Teses / dissertações: "Plants, Effect of zinc on"

1

Genc, Yusuf. "Screening for zinc efficiency in barley (Hordeum vulgare L.)". Title page, table of contents and summary only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phg324.pdf.

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Bibliography: leaves 229-250. The aims of the study were to develop a reliable method for screening for Zn efficiency as an alternative to the current field-based methods, and to determine the extent of genotypic variation in tolerance to Zn deficiency in barley.

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2

Mulyati. "Zinc requirements of transplanted oilseed rape". Thesis, Mulyati, (2004) Zinc requirements of transplanted oilseed rape. PhD thesis, Murdoch University, 2004. https://researchrepository.murdoch.edu.au/id/eprint/213/.

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Transplanting is a common practice for many horticultural crops and some field crops. Recently, transplanted oilseed rape (Brassica napus L.) crops have been reported to be sensitive to zinc (Zn) deficiency. However, Zn nutrition in transplanted field crops has not been investigated in detail. The objectives of this present research were to investigate whether transplanting increases external Zn requirements of transplanted oilseed rape, and the mechanisms of root function, growth and Zn uptake after transplanting including rhizosphere modification capacity by plant roots. The second objective was to examine the relative effects of root pruning and transplanting on Zn responses of oilseed rape, and the third objective was to determine external and internal Zn requirements of transplanted oilseed rape for diagnosing and predicting Zn deficiency. An experiment on a low Zn sand (DTPA extractable Zn 0.14 mg kg-1) was set up to determine whether transplanted oilseed rape had a higher Zn requirement than that of direct-sown plants. Low Zn supply depressed shoot dry weight, however, root growth was relatively more strongly suppressed than shoots. Maximum root dry weight required much higher external Zn for transplanted plants compared to direct-sown plants, whilst shoot dry weight required a similarly low external Zn supply. In addition, transplanted plants were sensitive to zinc deficiency during the early post-transplanting growth, and the response weakened as the plants recovered from root injury or transplanting stress. However, the transplanted plants also experienced root pruning before transplanting and so in this experiment the higher Zn requirement could have been due to root pruning or transplanting or both. A further experiment was undertaken to determine the comparative external Zn requirements of direct-sown and transplanted plants in well-stirred chelate-buffered solution culture where a rhizosphere effect on plant availability of Zn forms is absent and the effects of poor root-soil contact on post-transplanting growth are minimized. In solution culture at the same level of Zn supplied, direct- sown plants produced higher shoot and root dry matter and greater root length than those of transplanted plants. However, since a higher external Zn requirement was found for transplanted plants in buffered solution culture than for direct- sown plants, it was concluded that the higher Zn requirement was not related to decreased rhizosphere modification, to greater demand for Zn or to poor root-solution contact, but rather to the time required for transplanted plants to recover from transplanting and root injury. The recovery of root function in solution culture was more rapid than that in soil culture and expressed as a higher Zn requirement for shoot as well as root growth. It suggested that the delay in root recovery in soil culture was due to slower absorption of Zn from the soil after transplanting than was the case in solution culture. Chelate-buffered nutrient solution culture and harvesting plants successively at 5 day intervals until 25 days after transplanting was used to examine the mechanisms of the recovery of root growth and function. In this experiment, the external Zn requirement of transplanted plants was investigated with unpruned or pruned root systems. Plants with unpruned root system and sufficient Zn supply exhibited faster recovery from transplanting than those with pruned root system plants. The results suggest that root pruning impaired Zn uptake by plant roots and slowed down the root and shoot growth after transplanting. Increased solution Zn partly alleviated the effects of root pruning and presumably this is a major reason why transplanted oilseed rape had a high external Zn requirement. However, root pruning also appeared to impair water uptake, and may have suppressed shoot growth through sequestering carbon for new root growth and through decreased phytohormone production by roots. Since rapid root recovery of transplanted plants is essential for successful of growth in the field, Zn application to the nursery bed was explored as a starter fertilizer to stimulate root growth after transplanting. The objective of this experiment was to determine whether increasing the seedbed Zn would stimulate new root growth of transplanted oilseed rape, and therefore would alleviate the need for increased external Zn for post-transplanting growth. Results showed that adequate Zn concentration in the seedbed promoted the post-transplanting growth by stimulating the new root growth especially increased root length, and also hastened the recovery of root systems. However, high Zn concentration at transplanting still had a more dominant effect in stimulating the new root growth of oilseed rape after transplanting. The final experiment was set up using rhizobags with three rates of Zn supply and unpruned or pruned root systems. The purpose of this study was to investigate the chemical change in the rhizosphere and non-rhizosphere or bulk soil and its relationship to the recovery of root function after transplanting, and also to identify and quantify the organic acids in soil extracts of direct-sown and transplanted plants. The rhizosphere soil pH was lower than that of non-rhizosphere soil, and the decrease of soil pH was suggested as the mechanism of the increase of Zn availability and mobility in the rhizosphere soil. Direct-sown plants were more efficient in utilizing Zn than those of transplanted plants especially compared to those of plants with pruned root system. Zinc deficient plants excreted higher concentration of organic acids particularly citric acid, suggesting this was a mechanism of Zn mobilization and Zn uptake by roots of oilseed rape. The main implications of the present study for the management of Zn nutrition of transplanted crops were: the need to increase the Zn application to crops in the nursery and at transplanting compared to direct-sown plants; the possibility that external requirements of other nutrients will be greater in transplanted crops also requires further consideration; and in cropping systems where transplanting is practised, greater attention should be given to the avoidance of root damage during the transplanting.

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3

Mulyati. "Zinc requirements of transplanted oilseed rape". Murdoch University, 2004. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060109.135933.

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Transplanting is a common practice for many horticultural crops and some field crops. Recently, transplanted oilseed rape (Brassica napus L.) crops have been reported to be sensitive to zinc (Zn) deficiency. However, Zn nutrition in transplanted field crops has not been investigated in detail. The objectives of this present research were to investigate whether transplanting increases external Zn requirements of transplanted oilseed rape, and the mechanisms of root function, growth and Zn uptake after transplanting including rhizosphere modification capacity by plant roots. The second objective was to examine the relative effects of root pruning and transplanting on Zn responses of oilseed rape, and the third objective was to determine external and internal Zn requirements of transplanted oilseed rape for diagnosing and predicting Zn deficiency. An experiment on a low Zn sand (DTPA extractable Zn 0.14 mg kg-1) was set up to determine whether transplanted oilseed rape had a higher Zn requirement than that of direct-sown plants. Low Zn supply depressed shoot dry weight, however, root growth was relatively more strongly suppressed than shoots. Maximum root dry weight required much higher external Zn for transplanted plants compared to direct-sown plants, whilst shoot dry weight required a similarly low external Zn supply. In addition, transplanted plants were sensitive to zinc deficiency during the early post-transplanting growth, and the response weakened as the plants recovered from root injury or transplanting stress. However, the transplanted plants also experienced root pruning before transplanting and so in this experiment the higher Zn requirement could have been due to root pruning or transplanting or both. A further experiment was undertaken to determine the comparative external Zn requirements of direct-sown and transplanted plants in well-stirred chelate-buffered solution culture where a rhizosphere effect on plant availability of Zn forms is absent and the effects of poor root-soil contact on post-transplanting growth are minimized. In solution culture at the same level of Zn supplied, direct- sown plants produced higher shoot and root dry matter and greater root length than those of transplanted plants. However, since a higher external Zn requirement was found for transplanted plants in buffered solution culture than for direct- sown plants, it was concluded that the higher Zn requirement was not related to decreased rhizosphere modification, to greater demand for Zn or to poor root-solution contact, but rather to the time required for transplanted plants to recover from transplanting and root injury. The recovery of root function in solution culture was more rapid than that in soil culture and expressed as a higher Zn requirement for shoot as well as root growth. It suggested that the delay in root recovery in soil culture was due to slower absorption of Zn from the soil after transplanting than was the case in solution culture. Chelate-buffered nutrient solution culture and harvesting plants successively at 5 day intervals until 25 days after transplanting was used to examine the mechanisms of the recovery of root growth and function. In this experiment, the external Zn requirement of transplanted plants was investigated with unpruned or pruned root systems. Plants with unpruned root system and sufficient Zn supply exhibited faster recovery from transplanting than those with pruned root system plants. The results suggest that root pruning impaired Zn uptake by plant roots and slowed down the root and shoot growth after transplanting. Increased solution Zn partly alleviated the effects of root pruning and presumably this is a major reason why transplanted oilseed rape had a high external Zn requirement. However, root pruning also appeared to impair water uptake, and may have suppressed shoot growth through sequestering carbon for new root growth and through decreased phytohormone production by roots. Since rapid root recovery of transplanted plants is essential for successful of growth in the field, Zn application to the nursery bed was explored as a starter fertilizer to stimulate root growth after transplanting. The objective of this experiment was to determine whether increasing the seedbed Zn would stimulate new root growth of transplanted oilseed rape, and therefore would alleviate the need for increased external Zn for post-transplanting growth. Results showed that adequate Zn concentration in the seedbed promoted the post-transplanting growth by stimulating the new root growth especially increased root length, and also hastened the recovery of root systems. However, high Zn concentration at transplanting still had a more dominant effect in stimulating the new root growth of oilseed rape after transplanting. The final experiment was set up using rhizobags with three rates of Zn supply and unpruned or pruned root systems. The purpose of this study was to investigate the chemical change in the rhizosphere and non-rhizosphere or bulk soil and its relationship to the recovery of root function after transplanting, and also to identify and quantify the organic acids in soil extracts of direct-sown and transplanted plants. The rhizosphere soil pH was lower than that of non-rhizosphere soil, and the decrease of soil pH was suggested as the mechanism of the increase of Zn availability and mobility in the rhizosphere soil. Direct-sown plants were more efficient in utilizing Zn than those of transplanted plants especially compared to those of plants with pruned root system. Zinc deficient plants excreted higher concentration of organic acids particularly citric acid, suggesting this was a mechanism of Zn mobilization and Zn uptake by roots of oilseed rape. The main implications of the present study for the management of Zn nutrition of transplanted crops were: the need to increase the Zn application to crops in the nursery and at transplanting compared to direct-sown plants; the possibility that external requirements of other nutrients will be greater in transplanted crops also requires further consideration; and in cropping systems where transplanting is practised, greater attention should be given to the avoidance of root damage during the transplanting.

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4

Khan, Habib Ur Rahman. "Responses of chickpea (Cicer arietinum L.) to zinc supply and water deficits". Title page, contents and summary only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phk4446.pdf.

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Bibliography: leaves 201-228. Widespread deficiencies of mineral nutrients in soils along with limited moisture supply are considered major environmental stresses leading to yield losses in chickpea. This study was conducted to determine the zinc requirement of chickpea and the effect on plant water relations. Critical zinc concentration was estimated. It was found that high and low moisture regimes had no effect on critical zinc concentration and that the value remained almost the same in all chickpea genotypes. Sensitivity of 28 chickpea genotypes were evaluated at two zinc levels. Field studies on zinc fertilization in both Australia and Pakistan showed that the application of zinc increased grain yield in all chickpea genotypes. It was found that plants grown under zinc deficiency could not exploit available soil moisture and water use and water use efficiency was reduced, and concluded that high zinc availability may enhance the ability of plants to endure periods of drought by promoting osmotic adjustment.

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5

Neilsen, Denise. "Characterization and plant availability of zinc in British Columbia orchard soils". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72835.

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6

Deka, Priyanka. "The Effect of Zinc Oxide Nanoparticles on Plants, and on Host-Pathogen Interactions". Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29270.

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Zinc oxide nanoparticles (ZnO NPs) are a type of engineered nanomaterial that is currently being explored for use in different aspects of agriculture. So far, research on this area is limited to evaluating the phenotypical responses of plants to a high concentration of the NPs which is realistically not feasible in the actual environment. This research aims to investigate the molecular-level interactions between ZnO NPs and plants, together with another significant component of the environment, a fungal plant pathogen. Prior to studying these molecular-level interactions, the uptake of ZnO NPs in planta was validated using a fluorescent zinc ion sensor, Zinpyr-1 and a zinc ion chelator, TPEN in confocal laser scanning microscopy (CLSM) and Transmission Electron Microscopy (TEM). Phenotypical effects were studied in soybean plants exposed to environmentally relevant concentrations of ZnO NPs and bioaccumulation of zinc was studied in seeds of soybean and other soy products. The next phase of this research focused on investigating the physiological responses of plants exposed to ZnO NPs. This was achieved by elucidating the complete transcriptome of the plants using a Next Generation sequencing (NGS) platform, RNA seq. A significant part of this research emphasized on exploring the effects of ZnO NPs on host-pathogen interactions. The model monocot plant, barley was used in this study, together with a necrotrophic pathogen, Pyrenophora teres f. teres (Ptt). The barley line which was used, CI5791 is resistant to the disease Net Form Net Blotch (NFNB), caused by Ptt. Rapid responses of plants to ZnO NPs were observed that subsided at the later time-points, whereas the heightened responses to the pathogen alone (P) and combined application (ZnO NP + P) persisted. Exposure to ZnO NPs also induced transcriptional reprogramming in the Ptt inoculated plant that resulted in compromised immunity in the otherwise resistant barley, due to the persistence of salicylic acid (SA)-related genes. In ZnO NP-exposed Arabidopsis thaliana, the effects were contradictory. From the barley and Arabidopsis expression data, it could be concluded that both species react differently to ZnO NPs, giving a glimpse of the differential responses that ZnO NPs may elicit in different plant species.
USDA-NIFA
National Science Foundation (NSF)

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7

Wheal, Matthew Simon. "The influence of chlorsulfuron on the uptake and utilization of zinc by wheat /". Title page, table of contents and summary only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phw556.pdf.

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8

Nguyen, Thi Ngoc nga. "Functional expression of Plant Defensins type 1 for zinc tolerance in plants". Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20032/document.

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Plant Defensins type 1 (PDF1) sont principalement décrites pour leur rôle dans l'immunité innée en réponse à des attaques pathogènes via l'activation de la voie de signalisation de l'éthylène (Et) et de l'acide jasmonique (JA). Les défensines PDF1 du genre Arabidopsis sont également impliquées dans la tolérance cellulaire au zinc chez la levure. In planta, de nombreux résultats mettent en évidence une corrélation entre la forte accumulation des transcrits AhPDF1 et leur contribution dans la tolérance à un excès de zinc. Dans cette étude, l'analyse du transcriptome (qRT-PCR) révèle que les paralogues PDF1s, aussi bien chez A. thaliana que chez A. halleri sont très peu voire pas du tout sensibles au zinc. Toutefois, il y a une spécialisation des PDF1s en réponse à l'activation de la voie de l'acide jasmonique dans le genre Arabidopsis. De plus, la contribution fonctionnelle des membres de la famille PDF1s dans la tolérance au zinc a été caractérisée chez A. thaliana à l'aide d'une approche génétique combinant des mutants KO après insertion d'un ADN-T et la technologie de miRNA artificiel. L'étude de ces mutants souligne par ailleurs la diversité fonctionnelle au sein de la famille des défensines AtPDF1s qui ne confèrent pas toutes la tolérance au zinc. En effet, une diversité de déterminants moléculaires des PDF1s a été mise en évidence lors de cette étude. La forte accumulation des PDF1s n'est pas l'unique paramètre requis pour la tolérance au zinc. Il faut également considérer la spécificité de tissu où s'expriment ces PDF1s. A ces considérations s'ajoutent aussi des régulations post-transcriptionnelles et post-traductionnelles. L'étude de ces modifications est envisagée afin de comprendre la contribution des différentes défensines PDF1s dans la tolérance au zinc
Plant Defensin type 1 (PDF1s) are mainly recognized for their response to pathogen attack via ethylene (Et)/jasmonate (JA) signaling activation pathway. However, PDF1s originating from Arabidopsis genus also showed their capacity to induce cellular zinc tolerance up on expression in yeast. In planta, a group of observation highlighted the correlation of AhPDF1 high transcript accumulation for their contribution to zinc tolerance. Here, transcriptomic analysis (qRT-PCR) revealed that in both A. thaliana and A. halleri species, PDF1 paralogues were barely or not at all responsive to zinc. Nevertheless, there is a species specialization of PDF1s in response to activation of JA-signaling in Arabidopsis genus. In addition, in A. thaliana, the functional contribution of PDF1 members in zinc tolerance was investigated through genetic approach. Examining combination of T-DNA insertion knockout mutant and artificial miRNA, these studies were first direct demonstration of the functional involvement of AtPDF1s in zinc tolerance. These also highlighted the functional diversity among AtPDF1s because not all of them could play a role in zinc tolerance. Indeed, a diversity of PDF1 molecular determinants for zinc tolerance in plants was underlined. Remarkably, PDF1 high transcript is not the only important parameter for zinc tolerance and PDF1 tissue specificity could be an important factor to consider. Moreover, post-transcriptional and post-translational regulation might occur. Studies on these modifications are now the further questions in order to understand the contribution of the different PDF1s to zinc tolerance

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9

Ramesh, Sunita. "Molecular mechanism of zinc uptake and regulation in cereals". Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phr1724.pdf.

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Bibliography: leaves 174-204. "This work provides a starting point for understanding the molecular mechanisms of zinc uptake and the regulation of zinc transport in cereals. Zinc efficient cereals would yield more on soild with low zinc and could potentially result in increased zinc content grain."

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10

Singbo, Arnaud. "The effect of zinc and soil ph on grain yield and nutrient concentrations in spring wheat cultivated on potted soil". Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2845.

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Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2018.
Zinc deficiency on various soil types have been reported in arable soils of sub Saharan Africa (SSA) including South Africa. A pot trial was conducted at the Cape Peninsula University of Technology, Wellington campus to investigate the interaction of different application rates of Zn at various soil pH on the grain yield and quality of spring wheat in a completely randomized factorial design replicated three times. The four soil pH tested were: pHA: 5.1, pHB: 5.6, pHC: 6.1, pHD: 6.6 which correspond to lime application at 0, 0.5, 1 and 1.5 t/ha. Five Zn rates (Zn1: 3.5; Zn2: 4.5; Zn3: 5.5 Zn4: 6.5, and Zn5: 7.5 mg /kg soil which correspond to Zn1: 7; Zn2: 9; Zn3: 11; Zn4: 13 and Zn5: 15 kg /ha) were applied at two (planting and flowering) growth stages. Yield and yield component data collected were analyzed using SAS version 9.2 and means were separated by Duncun’s Multiple Range Test (DMRT). The results showed that grain yield and yield components were significantly affected by lime application pHC (6.1): 1t/ha at planting. Zn application at planting had no significant effect on the grain yield and yield components. However, at flowering, the simultaneous increase of Zn along with increase in lime positively affected grain yield and yield components. Plant analysis showed that at both stages (planting and flowering), Zn application, especially at pH 6.6, significantly increased P, K, Ca, Na, Mg Fe, Cu and B concentrations in wheat grain, but the concentrations of N, Mn, Zn and protein remained unaffected. Zn application had no effect on most nutrients due to the presence of lime. While the absence of lime, Zn4: 6.5mg/kg (corresponding to 13kg/ha) significantly increased the nutrients. In addition, Zn3: 5.5mg/kg (corresponding to 11kg/ha) promoted Zn absorption by grain in all treatments.

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11

Gettier, Stacy W. "Corn response to long-term application of CuSO₄, ZnSO₄ and Cu-enriched pig manure". Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49779.

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12

Sadeghzadeh, Behzad. "Mapping of chromosome regions associated with seed zinc accumulation in barley". University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0204.

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[Truncated abstract] Zinc deficiency in crops is the most widespread micronutrient deficiency, with about 50% of the cereal-growing areas worldwide containing low levels of plant-available Zn. Zinc plays multiple key roles in different metabolic and physiological processes; its deficiency in crops reduces not only grain yield, but also the nutritional quality of grains. Insufficient micronutrient intake, particularly Zn and Fe, afflicts over 3 billion people in the world, mainly in developing countries. Increasing the amount of Zn in food crops can contribute to improving the Zn status of people. Furthermore, Zn-dense seeds have agronomic benefits, resulting in greater seedling vigour, bigger root system and higher crop yield when sowed to soils with low plant-available Zn. Enhancing nutrient content and nutritional quality of crops for human nutrition is a global challenge currently, but it was mostly ignored during the breeding process in the past. There is a significant genotypic variation for seed Zn accumulation in several crops (including barley) which could be exploited in the breeding programs to produce genotypes with higher seed Zn concentration and content. However, the progress in Zn efficiency until now has mainly relied on conventional plant breeding approaches that have had limited success. Therefore, reliable alternative methods are required. Enhancing mineral nutrition through plant biotechnology may be a sustainable and beneficial approach in developing Zn-dense seeds in the staple crops. ... This DNA band was sequenced and converted into a simple sequence-specific PCR-based marker, which was designated as SZnR1 (seed Zn-regulator1). The developed marker is very easy to score, is inexpensive to run and amenable for a large number of plant samples. The successful development of SZnR1 molecular marker linked to chromosome region associated with seed Zn concentration and content using MFLP in this study illustrates the advantage of this technique over some other DNA fingerprinting methods used for identification of molecular markers for marker-assisted selection (MAS). In conclusion, the greater Zn efficiency of Sahara over Clipper under sufficient Zn supply may be attributed to its higher uptake of Zn. It appears that soil-based pot experiments under controlled condition may offer potential improvements over field experiments in screening for seed Zn accumulation. Shoot and seed Zn concentration and content can be used to diagnose the Zn statues of barley genotypes, and may be a useful selection criterion for Zn efficiency in large populations like doubled-haploid populations aimed at developing molecular markers for Zn efficiency. Identified QTLs influencing seed Zn concentration were repeatable in the field and glasshouse conditions, suggesting their robustness across environments as well as their value in marker-assisted selection. The developed PCR-based marker SZnR1 and other molecular markers associated with the QTLs on the short and long arms of chromosome 2H have the potential to be used for marker-assisted selection in breeding for Zn-dense seed in barley.

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Lima, Neto Antonio João de [UNESP]. "Crescimento e acúmulo de nutrientes em porta-enxertos de caramboleira adubados com zinco". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/110329.

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O Brasil está entre os maiores produtores mundiais de carambola, sendo o estado de São Paulo responsável pela maior parte da produção nacional. Apesar da importância da cultura, ainda são escassas na literatura informações sobre adubação, principalmente quanto ao uso de micronutrientes na produção de porta-enxertos. Diante da falta de informações, o trabalho objetivou avaliar a influência do zinco sobre o crescimento, composição mineral e eficiência nutricional de porta-enxertos de caramboleira. O trabalho foi desenvolvido entre os meses de setembro de 2012 e fevereiro de 2013, em um viveiro comercial de produção de mudas, localizado em Taquaritinga, SP. O delineamento utilizado foi em blocos casualizados, com cinco doses de zinco: D0 = zero de Zn; D1 = 2; D2 = 4; D3 = 6; e, D4 = 8 mg de Zn dm-3, quatro repetições e três plantas por parcela. Aos 170 dias após a aplicação do zinco avaliou-se: altura das plantas, diâmetro do caule e número de folhas. Em seguida, as plantas foram coletadas, separadas em parte aérea e raízes, secas, pesadas, moídas e determinados os teores, calculados os acúmulos, a eficiência de absorção, de transporte e de utilização de macro e micronutrientes. Todos os parâmetros de crescimento avaliados, responderam à aplicação das doses de zinco. O acúmulo de Zn, P, K, Mg e S na planta, também responderam à aplicação de zinco. As doses mais elevadas de zinco aumentaram a eficiência de absorção de Zn e, reduziram o transporte de Ca e Mn. Pelos resultados, conclui-se que, o maior desenvolvimento dos porta-enxertos de caramboleira esteve associado à dose entre 3,1 e 3,8 mg de Zn dm-3. Doses elevadas de zinco promovem menor teor, acúmulo e eficiência de utilização para a maioria dos macro e micronutrientes
Brazil is among the world's largest producers of starfruit, with the state of São Paulo accounting for most of the national production. Despite the importance of this culture, information about the fertilization of this culture is scarce in literature, particularly regarding the use of micronutrients in producing rootstocks. Due to lack of information, this study aimed to evaluate the influence zinc has on growth, mineral composition and nutritional efficiency of star fruit rootstocks. The study was conducted between the months of September 2012 and February 2013 in a seedling production nursery located in Taquaritinga, SP. A randomized block design with five doses of zinc was used to carry out the study with four replications and three plants per plot: D0 = zero, D1 = 2, D2 = 4, D3 = 6, and D4 = 8 mg Zn dm-3. At 170 days after applying the zinc, the plant height, stem diameter and number of leaves were analyzed. The plants were then collected and divided into shoots and roots, dried, weighed, ground and the content was evaluated. The accumulations were calculated as well as the efficiency of absorption, transport and utilization of macro and micronutrients. All growth parameters evaluated responded to the zinc doses. The accumulation of Zn, P, K, Mg and S in the plant also responded to the zinc. The higher doses of zinc increased the absorption efficiency of Zn and reduced the transport of Ca and Mn. From these results, it is concluded that largest development of starfruit rootstocks was associated with the dose between 3.1 and 3.8 mg of Zn dm-3. High doses of zinc promote lower content, accumulation and utilization efficiency for most macro and micronutrients

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14

Lima, Neto Antonio João de. "Crescimento e acúmulo de nutrientes em porta-enxertos de caramboleira adubados com zinco /". Jaboticabal, 2014. http://hdl.handle.net/11449/110329.

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Orientador: William Natale
Banca: Antonio Baldo Geraldo Martins
Banca: Danilo Eduardo Rozane
Resumo: O Brasil está entre os maiores produtores mundiais de carambola, sendo o estado de São Paulo responsável pela maior parte da produção nacional. Apesar da importância da cultura, ainda são escassas na literatura informações sobre adubação, principalmente quanto ao uso de micronutrientes na produção de porta-enxertos. Diante da falta de informações, o trabalho objetivou avaliar a influência do zinco sobre o crescimento, composição mineral e eficiência nutricional de porta-enxertos de caramboleira. O trabalho foi desenvolvido entre os meses de setembro de 2012 e fevereiro de 2013, em um viveiro comercial de produção de mudas, localizado em Taquaritinga, SP. O delineamento utilizado foi em blocos casualizados, com cinco doses de zinco: D0 = zero de Zn; D1 = 2; D2 = 4; D3 = 6; e, D4 = 8 mg de Zn dm-3, quatro repetições e três plantas por parcela. Aos 170 dias após a aplicação do zinco avaliou-se: altura das plantas, diâmetro do caule e número de folhas. Em seguida, as plantas foram coletadas, separadas em parte aérea e raízes, secas, pesadas, moídas e determinados os teores, calculados os acúmulos, a eficiência de absorção, de transporte e de utilização de macro e micronutrientes. Todos os parâmetros de crescimento avaliados, responderam à aplicação das doses de zinco. O acúmulo de Zn, P, K, Mg e S na planta, também responderam à aplicação de zinco. As doses mais elevadas de zinco aumentaram a eficiência de absorção de Zn e, reduziram o transporte de Ca e Mn. Pelos resultados, conclui-se que, o maior desenvolvimento dos porta-enxertos de caramboleira esteve associado à dose entre 3,1 e 3,8 mg de Zn dm-3. Doses elevadas de zinco promovem menor teor, acúmulo e eficiência de utilização para a maioria dos macro e micronutrientes
Abstract: Brazil is among the world's largest producers of starfruit, with the state of São Paulo accounting for most of the national production. Despite the importance of this culture, information about the fertilization of this culture is scarce in literature, particularly regarding the use of micronutrients in producing rootstocks. Due to lack of information, this study aimed to evaluate the influence zinc has on growth, mineral composition and nutritional efficiency of star fruit rootstocks. The study was conducted between the months of September 2012 and February 2013 in a seedling production nursery located in Taquaritinga, SP. A randomized block design with five doses of zinc was used to carry out the study with four replications and three plants per plot: D0 = zero, D1 = 2, D2 = 4, D3 = 6, and D4 = 8 mg Zn dm-3. At 170 days after applying the zinc, the plant height, stem diameter and number of leaves were analyzed. The plants were then collected and divided into shoots and roots, dried, weighed, ground and the content was evaluated. The accumulations were calculated as well as the efficiency of absorption, transport and utilization of macro and micronutrients. All growth parameters evaluated responded to the zinc doses. The accumulation of Zn, P, K, Mg and S in the plant also responded to the zinc. The higher doses of zinc increased the absorption efficiency of Zn and reduced the transport of Ca and Mn. From these results, it is concluded that largest development of starfruit rootstocks was associated with the dose between 3.1 and 3.8 mg of Zn dm-3. High doses of zinc promote lower content, accumulation and utilization efficiency for most macro and micronutrients
Mestre

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15

Genter, Robert B. "Population and community changes of attached-algae to zinc stress alone and in combination with selected environmental variables". Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49778.

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16

Winarko, Clementinus. "Response of corn to high levels of CuSO₄ and ZnSO₄ applications". Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45656.

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Copper and Zn deficiencies of crop plants occur in various areas throughout the world. The sulfate forms of Cu and Zn are generally used to correct these micronutrient deficiencies. In agricultural practices, Cu and Zn are applied to soils not only as a fertilizer but also as manures, pesticides and waste materials such as sewage sludge. High levels of Cu and Zn application to agricultural soils are considered to pose a potential hazard to plants and animals. Research findings have not established Cu and Zn levels that either injure plants or increase Cu and Zn concentrations in edible plant portions to undesirably high levels. Published data on the fate of applied Cu and Zn indicate that there is little, if any, downward movement of these micronutrients in soils and that, with time, applied Cu and Zn revert to plant unavailable forms in soils.

Master of Science

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17

Thongbai, Pongmanee. "The influence of Zn nutritional status on the severity of Rhizoctonia root rot of cereals". Title page, table of contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09pht486.pdf.

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18

Souza, Sarah Caroline Ribeiro 1986, e Sara Adrián López de 1971 Andrade. "Tolerância aos metais pesados chumbo e zinco e potencial fitorremediador de mudas de espécies arbóreas". [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315377.

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Orientadores: Marlene Aparecida Schiavinato, Sara Adrian Lopez de Andrade
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-15T21:26:06Z (GMT). No. of bitstreams: 1 Souza_SarahCarolineRibeiro_M.pdf: 990180 bytes, checksum: a52442f68f3a27dfa82cded6425db23c (MD5) Previous issue date: 2010
Resumo: A contaminação do solo por metais pesados (MPs), causada por processos naturais ou atividade humana, é um dos mais graves problemas ambientais devido à persistência e alto poder de toxicidade dos MPs. Em ambientes contaminados por MPs, as plantas podem apresentar uma série de distúrbios fisiológicos e nutricionais. No entanto, algumas espécies de plantas são tolerantes aos MPs e essa tolerância tem sido selecionada durante a evolução, e envolve diversos mecanismos. A associação com fungos micorrízicos arbusculares (FMAs) pode reduzir os efeitos negativos do estresse induzido por altas concentrações de metais sobre a planta hospedeira. Considerando a existência de plantas tolerantes, a fitorremediação, especialmente com espécies arbóreas, aparece como uma estratégia eficiente para a reabilitação de áreas contaminadas com MPs, uma vez que essas espécies imobilizam os metais absorvidos por mais tempo em seus tecidos. Assim, este estudo teve como objetivos: avaliar a tolerância, o acúmulo e a distribuição dos MPs, Pb e Zn, em três espécies de leguminosas nas diferentes partes das plantas; avaliar a influência destes metais na colonização micorrízica e na fixação biológica de nitrogênio e avaliar o potencial fitorremediador de cada espécie. Foram realizados dois experimentos, um com Pb e outro com Zn, com delineamento experimental totalmente casualizado e em esquema fatorial 3 x 4. Os tratamentos consistiram em três espécies de leguminosas arbóreas Mimosa caesalpiniaefolia (sansão-do-campo), Erythrina speciosa (eritrina-candelabro) e Schizolobium parahyba (guapuruvu) e quatro concentrações de metais, 0, 250, 500 e 1000 mg.dm-3 de Pb e 0, 200, 400 e 600 mg.dm-3 de Zn, adicionados ao solo na forma de acetato de chumbo e sulfato de zinco. Após aproximadamente 180 dias de cultivo as mudas foram coletadas. Determinaram-se altura, área foliar total, massa da matéria seca (MS) da parte aérea e raízes, número de nódulos e MS de nódulos das espécies que nodulam. Na espécie que não nodula, S. parahyba, foi feita a medição da raiz pivotante e o volume total de raízes. Foram feitas as determinações dos teores de Pb e Zn, dos nutrientes essenciais e calculado o índice de translocação (IT). Foram determinados o conteúdo de pigmentos fotossintéticos, a atividade da nitrogenase, aminoácidos livres, nitrato, amônia, peroxidação lipídica (MDA) e a taxa de colonização micorrízica. Os dados foram submetidos à análise de variância, análise de regressão e teste de Tukey. Verificou-se que altas concentrações de Zn adicionadas ao solo afetam mais significativamente o desenvolvimento de mudas de espécies arbóreas quando comparadas às concentrações de Pb utilizadas. Todas as espécies apresentam maiores concentrações de Zn e Pb nas raízes que agem como uma barreira à translocação dos MPs, considerado um mecanismo de fitoestabilização. O fato de serem espécies de leguminosas arbóreas de crescimento rápido, de fácil propagação, sistema radicular extenso e aliado ao fato de conseguirem absorver e concentrar os metais pesados Pb e Zn em suas raízes, sugere que estas espécies arbóreas analisadas podem ser potencias plantas fitorremediadoras de solos moderadamente contaminados, sendo que, para o Pb a espécie mais tolerante seria M. caesalpiniaefolia e para o Zn, a E. speciosa.
Abstract: Soil contamination by heavy metals (HM), caused by natural processes or human activity, is one of the most serious environmental problems due to their persistence and high toxicity potential. In HM contaminated environments, plants may present a series of physiological and nutritional disorders. However, some plant species are tolerant to HM and this tolerance has been selected during evolution. The mechanisms involved in plant tolerance to HM excess are diverse and varied. The association with arbuscular mycorrhizal fungi (AMF) can reduce the negative effects of stress induced by high concentrations of metals to the host plant. Considering the existence of tolerant plants, phytoremediation appears as na efficient strategy for the rehabilitation of areas contaminated with HM, especially using tree species, since these species immobilize absorbed metals for greater time periods in their tissues. Thus, this study aimed to evaluate the tolerance, accumulation and distribution of Pb and Zn in three species of leguminous trees, and further, to evaluate the influence of these metals in mycorrhizal colonization and nitrogen fixation and evaluate the phytoremediator potential of each of the studied species. For this purpose, two experiments were conducted, one with Pb and another with Zn, with a completely randomized experimental design in a factorial 3 x 4 scheme. The treatments consisted of three species of tree legumes Mimosa caesalpiniaefolia (sansão-do-campo), Erythrina speciosa (eritrinacandelabro) and Schizolobium parahyba (guapuruvu) and four concentrations of metal, 0, 250, 500 and 1000 mg.dm-3 Pb and 0, 200, 400 and 600 mg.dm-3 Zn added to soil in the form of lead acetate and zinc sulfate. Approximately 180 days after sowing, the seedlings were collected. We determined the height and total leaf area, the dry matter (DM) of shoots and roots, nodule number and nodule DM of nodulating species. In species that do not nodulate, S. parahyba, measurements were made of the tap root and root volume. Determinations were made of the levels of Pb and Zn as well as essential nutrients and the rate of translocation (IT) was calculated. The content of photosynthetic pigments was determined as well as photosynthesis, nitrogenase activity, amino acids, nitrate, ammonia and lipid peroxidation (MDA) and the rate of colonization was estimated. The data were subjected to analysis of variance, regression analysis and the Tukey test (5% significance). It was found that the higher concentrations of Zn added to soil affected the development of seedlings of the tree species studied more significantly than those of Pb. All species had higher Zn and Pb concentrations in their root, indicating this organ acts as a barrier for metal translocation to the shoots in these plants, considered a phytostabilization mechanism. The fact that these species are fast growing, easily propagated and have a extensive root system that can absorb and concentrate Pb and Zn, suggests that they have potential for use in phytoremediation of contaminated soils.
Mestrado
Biologia Vegetal
Mestre em Biologia Vegetal

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19

Hodgkinson, Mark. "Cause and control of oil induced phytotoxicity". Thesis, Queensland University of Technology, 1999.

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20

Mirouze, Marie. "Recherche de gènes impliqués dans la tolérance au zinc chez l'espèce modèle hyperaccumulatrice de zinc Arabidopsis halleri : un nouveau rôle possible pour les défensines de plantes". Montpellier 2, 2005. http://www.theses.fr/2005MON20183.

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Le zinc est un métal essentiel pour les êtres vivants, mais sa présence en excès dans la cellule peut s'avérer toxique. Or certaines plantes dites hyperaccumulatrices ont la capacité surprenante d’accumuler de fortes quantités de zinc dans leurs parties aériennes (jusqu’à 1% de leur matière sèche), sans présenter de symptômes de toxicité. La plante tolérante et hyperaccumulatrice de zinc Arabidopsis halleri représente, par sa proximité phylogénétique avec la plante modèle Arabidopsis thaliana, un matériel biologique parfaitement adapté pour aborder les mécanismes moléculaires, encore mal connus, de l’homéostasie du zinc chez les plantes. L’expression hétérologue d’une banque d’ADNc de feuilles d’A. Halleri dans la levure Saccharomyces cerevisiae en conditions de toxicité en zinc nous a permis d’isoler 5 clones indépendants présentant un phénotype de tolérance au zinc. Les ADNc correspondants codent tous des protéines fortement homologues à des protéines appelées défensines de plantes (PDF) chez Arabidopsis thaliana. Ces protéines sont ubiquitaires chez les plantes mais également chez les mammifères où elles sont connues pour participer aux mécanismes de défense immunitaire innée. Cependant, à notre connaissance, aucun rôle des défensines dans la physiologie des métaux n’a été établi à ce jour. Une des défensines d’A. Halleri, une fois exprimée chez A. Thaliana, confère aux plantes transgéniques une tolérance accrue à des concentrations toxiques de zinc. De plus, chez A. Halleri, l’expression des défensines semble être induite par un traitement des plantes par le zinc, que ce soit au niveau des transcrits ou des protéines. Ces résultats originaux proposent un nouveau rôle des défensines de plantes dans l’homéostasie des métaux
Zinc (Zn) is an essential metal that can become highly toxic when present in excess amount in the cell, indicating that Zn homeostasis has to be tightly regulated. Interestingly, Arabidopsis halleri, a close Arabidopsis thaliana relative, is able to accumulate more than 1% DW of Zn in its shoots without showing any toxicity symptom suggesting the existence of dedicated detoxification mechanisms. We exploit this natural Zn tolerant and hyperaccumulator plant species to characterize the molecular basis of Zn tolerance in plants. To identify A. Halleri genes involved in Zn tolerance, we carried out a functional screening by expressing an A. Halleri cDNA library in the yeast Saccharomyces cerevisiae. Selecting A. Halleri cDNAs conferring Zn tolerance in yeast grown on Zn contaminated medium, we isolated five cDNAs encoding for A. Halleri defensins (AhPDFs). Overexpression of one of them (AhPDF1. 1) in A. Thaliana Col-0 gave rise to a Zn tolerance phenotype. Thus, at least one of the AhPDF members is able to confer Zn tolerance both in yeast and in planta. In A. Halleri, AhPDFs are constitutively accumulated at a higher level in shoots compared to A. Thaliana. Furthermore, both AhPDF1. 1 mRNA and AhPDFs steady state levels were shown to be increased upon Zn treatment. Therefore, we assume that AhPDFs could be involved in A. Halleri Zn tolerance. Finally, this work highlights that plant defensins, well-known for their antifungal actvity, could also be implicated in metal physiology

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21

au, 30075885@student murdoch edu, e Ross F. Brennan. "Zinc Application and its Availability to Plants". Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050602.142302.

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Globally, low zinc (Zn) soils are widespread, but one of the largest expanses of such soils is in south west Australia (WA). Early Zn research in the region determined how much fertiliser Zn was required for profitable production of spring wheat (Triticium aestivum L.) and subterranean clover (Trifolium subterraneanum L), the major crop and pasture species at the time. The research showed that Zn sulfate and ZnO were equally effective Zn fertilisers, but ZnO was cheaper and so was widely used. The research indicated that in the year of application, depending on soil type, between 0.5-1.5 kg Zn/ha provided adequate Zn for the production of wheat and subterranean clover. The length of time that a single application of Zn fertiliser remains fully effective in maintaining the production of crops and pasture in future years (residual value; (RV)) had not been determined. This knowledge of the RV of Zn fertilisers is required for soils of WA. The experiments that measured the RV of fertiliser Zn for spring wheat and subterranean clover form the bulk of this thesis. The soils in the region were also initially acutely phosphorus (P) deficient requiring the application of fertiliser P for profitable production. Single superphosphate was the P fertiliser initially used. It was manufactured locally using phosphate rock imported from Nauru and Christmas Islands. This phosphate rock also contained much Zn, and the single superphosphate manufactured from it contained 400-600 mg Zn/kg. At amounts of application needed to provide adequate P, the Zn-contaminated superphosphate also supplied about 90 g Zn/ha. Therefore, early field experiments measured the RV of ZnO applied to soil when single superphosphate was applied annually at >150 kg/ha. In these experiments, the RV of Zn was measured when different amounts of fertiliser nitrogen (N) was applied. This was because it has recently been very profitable to apply fertiliser N to wheat crops, which greatly increased grain yields and so may have increased the demand for Zn, thereby probably decreasing the RV of the original ZnO application. In these experiments, there were many nil-Zn plots. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. No Zn deficiency was detected for up to 23 years after applying ZnO while applying superphosphate at >150 kg/ha per year and for all amounts of N applied. Subsequently cheap imported DAP fertiliser was used for wheat crops instead of locally produced Zn-contaminated single superphosphate and urea. The imported DAP contained about 50 mg Zn/kg (1/12 that of single superphosphate). This new fertiliser strategy induced Zn deficiency in many wheat crops. This led to further field studies to determine the RV of ZnO fertiliser when DAP was applied. The experiments also included 2 Zn-contaminated single superphosphate treatments. In one, no ZnO was applied, and superphosphate was applied at >150 kg/ha per year to match the amount of P applied as DAP to the other treatments. The other treatment was the same, except 1.5 kg/ha Zn as ZnO was applied in the first year only. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. Relative to freshly-applied Zn in each year, the RV of the original ZnO treatments decreased as the length of time that the Zn was in contact with soil increased. However, the rate of decline in the RV was also found to differ with soil type, and was affected by soil pH, clay and organic carbon content of soil, and in alkaline soils with the calcium carbonate content of soil. Parallel glasshouse studies measured the RV of Zn, as Zn sulfate, for wheat and subterranean clover, using many soils from WA and other Australian States. The glasshouse studies also showed that the rate of decline in the RV of the original Zn application varied markedly with soil type and was strongly influenced by soil pH, clay and organic carbon content of soil, and in the alkaline soils, the amount of calcium carbonate in soil. In the above studies, the RV of fertiliser Zn was measured relative to freshly-applied Zn using yield of plants (shoots and grain for wheat, shoots for clover), Zn content in shoots and grain, and soil test Zn using the ammonium oxalate and DTPA procedures. In addition, Zn concentration in young tissue and rest of shoots (glasshouse studies) and young tissue and whole shoots (field studies) was measured, and Zn concentration related to 90 % of the maximum yield (critical Zn in plant parts) was determined. The studies showed that the DTPA soil test procedure, together with soil pH, and clay and organic matter content of soil, was an accurate prognostic test for indicating when Zn deficiency was likely in the next clover or wheat crop. The study confirmed that young tissue (youngest fully expanded leaves) provided critical plant test values for diagnosing Zn deficiency in plants. The plant and soil tests for Zn are now used by commercial soil and tissue testing laboratories. When Zn deficiency was diagnosed early in field grown wheat, Zn sprays can be applied to the crop foliage to prevent or minimise decreases in grain yields at the end of the growing season. Zn sulfate and Zn chelate are the most widely used compounds. This thesis reports the results of a field study to compare the effectiveness of the two compounds when the spray was applied at two growth stages of wheat (Gs14; seedling growth and Gs24; tillering). In addition, Zn applied with the seed while sowing the wheat crop was also included. Zinc applied to the soil while sowing was the most effective treatment. Zn chelate was more effective as a spray than Zn sulfate when applied at the earlier growth stage, but Zn sulfate was cheaper, and both sprays were equally effective when applied at the later growth stage. Recently in the region, durum wheat (T. durum L.), narrow-leafed lupin (Lupinus angustifolius L.), yellow lupin (L. luteus L.), white lupin (L. albus L.), canola (Brassica napus L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.) and lentil (Lens culinaris Medik) were all increasingly grown in rotation with spring wheat. Consequently, the Zn requirement of the new crops was compared with the Zn requirements of spring wheat. Species requiring less Zn than spring wheat to produce the same relative yield were faba bean, chickpea, albus lupin and canola; species requiring more Zn were lentil and durum wheat. Spreadsheet models were developed to determine when re-application of fertiliser Zn was required for low and high production systems. Relative to freshly-applied Zn, the rate of decline in the RV of Zn applied in a previous year varied depending on the amount of Zn applied, time the Zn was in contact with soil since application, properties of the soil (soil pH, % clay, % organic carbon, % free calcium carbonate), plant species, and the amount of Zn removed in harvested grain or hay. The thesis has culminated in a better understanding of Zn in the agricultural production systems of WA. The distribution and correction of Zn deficiency is now predictable for the many soil types and cropping systems of WA. Accurate identification of Zn deficiency for a range of crop and pasture species by plant analyses, typically the youngest mature leaf, is now possible for local conditions. With the calibration of the DTPA Zn soil test for soils of WA, particularly for wheat the major crop species grown in WA, prognosis of potential Zn deficiency can now be predicted before the appearance of Zn deficiency or loss in plant production.

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22

Brennan, Ross F. "Zinc application and its availability to plants". Thesis, Brennan, Ross F. (2005) Zinc application and its availability to plants. PhD thesis, Murdoch University, 2005. https://researchrepository.murdoch.edu.au/id/eprint/436/.

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Globally, low zinc (Zn) soils are widespread, but one of the largest expanses of such soils is in south west Australia (WA). Early Zn research in the region determined how much fertiliser Zn was required for profitable production of spring wheat (Triticium aestivum L.) and subterranean clover (Trifolium subterraneanum L), the major crop and pasture species at the time. The research showed that Zn sulfate and ZnO were equally effective Zn fertilisers, but ZnO was cheaper and so was widely used. The research indicated that in the year of application, depending on soil type, between 0.5-1.5 kg Zn/ha provided adequate Zn for the production of wheat and subterranean clover. The length of time that a single application of Zn fertiliser remains fully effective in maintaining the production of crops and pasture in future years (residual value; (RV)) had not been determined. This knowledge of the RV of Zn fertilisers is required for soils of WA. The experiments that measured the RV of fertiliser Zn for spring wheat and subterranean clover form the bulk of this thesis. The soils in the region were also initially acutely phosphorus (P) deficient requiring the application of fertiliser P for profitable production. Single superphosphate was the P fertiliser initially used. It was manufactured locally using phosphate rock imported from Nauru and Christmas Islands. This phosphate rock also contained much Zn, and the single superphosphate manufactured from it contained 400-600 mg Zn/kg. At amounts of application needed to provide adequate P, the Zn-contaminated superphosphate also supplied about 90 g Zn/ha. Therefore, early field experiments measured the RV of ZnO applied to soil when single superphosphate was applied annually at >150 kg/ha. In these experiments, the RV of Zn was measured when different amounts of fertiliser nitrogen (N) was applied. This was because it has recently been very profitable to apply fertiliser N to wheat crops, which greatly increased grain yields and so may have increased the demand for Zn, thereby probably decreasing the RV of the original ZnO application. In these experiments, there were many nil-Zn plots. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. No Zn deficiency was detected for up to 23 years after applying ZnO while applying superphosphate at >150 kg/ha per year and for all amounts of N applied. Subsequently cheap imported DAP fertiliser was used for wheat crops instead of locally produced Zn-contaminated single superphosphate and urea. The imported DAP contained about 50 mg Zn/kg (1/12 that of single superphosphate). This new fertiliser strategy induced Zn deficiency in many wheat crops. This led to further field studies to determine the RV of ZnO fertiliser when DAP was applied. The experiments also included 2 Zn-contaminated single superphosphate treatments. In one, no ZnO was applied, and superphosphate was applied at >150 kg/ha per year to match the amount of P applied as DAP to the other treatments. The other treatment was the same, except 1.5 kg/ha Zn as ZnO was applied in the first year only. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. Relative to freshly-applied Zn in each year, the RV of the original ZnO treatments decreased as the length of time that the Zn was in contact with soil increased. However, the rate of decline in the RV was also found to differ with soil type, and was affected by soil pH, clay and organic carbon content of soil, and in alkaline soils with the calcium carbonate content of soil. Parallel glasshouse studies measured the RV of Zn, as Zn sulfate, for wheat and subterranean clover, using many soils from WA and other Australian States. The glasshouse studies also showed that the rate of decline in the RV of the original Zn application varied markedly with soil type and was strongly influenced by soil pH, clay and organic carbon content of soil, and in the alkaline soils, the amount of calcium carbonate in soil. In the above studies, the RV of fertiliser Zn was measured relative to freshly-applied Zn using yield of plants (shoots and grain for wheat, shoots for clover), Zn content in shoots and grain, and soil test Zn using the ammonium oxalate and DTPA procedures. In addition, Zn concentration in young tissue and rest of shoots (glasshouse studies) and young tissue and whole shoots (field studies) was measured, and Zn concentration related to 90 % of the maximum yield (critical Zn in plant parts) was determined. The studies showed that the DTPA soil test procedure, together with soil pH, and clay and organic matter content of soil, was an accurate prognostic test for indicating when Zn deficiency was likely in the next clover or wheat crop. The study confirmed that young tissue (youngest fully expanded leaves) provided critical plant test values for diagnosing Zn deficiency in plants. The plant and soil tests for Zn are now used by commercial soil and tissue testing laboratories. When Zn deficiency was diagnosed early in field grown wheat, Zn sprays can be applied to the crop foliage to prevent or minimise decreases in grain yields at the end of the growing season. Zn sulfate and Zn chelate are the most widely used compounds. This thesis reports the results of a field study to compare the effectiveness of the two compounds when the spray was applied at two growth stages of wheat (Gs14; seedling growth and Gs24; tillering). In addition, Zn applied with the seed while sowing the wheat crop was also included. Zinc applied to the soil while sowing was the most effective treatment. Zn chelate was more effective as a spray than Zn sulfate when applied at the earlier growth stage, but Zn sulfate was cheaper, and both sprays were equally effective when applied at the later growth stage. Recently in the region, durum wheat (T. durum L.), narrow-leafed lupin (Lupinus angustifolius L.), yellow lupin (L. luteus L.), white lupin (L. albus L.), canola (Brassica napus L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.) and lentil (Lens culinaris Medik) were all increasingly grown in rotation with spring wheat. Consequently, the Zn requirement of the new crops was compared with the Zn requirements of spring wheat. Species requiring less Zn than spring wheat to produce the same relative yield were faba bean, chickpea, albus lupin and canola; species requiring more Zn were lentil and durum wheat. Spreadsheet models were developed to determine when re-application of fertiliser Zn was required for low and high production systems. Relative to freshly-applied Zn, the rate of decline in the RV of Zn applied in a previous year varied depending on the amount of Zn applied, time the Zn was in contact with soil since application, properties of the soil (soil pH, % clay, % organic carbon, % free calcium carbonate), plant species, and the amount of Zn removed in harvested grain or hay. The thesis has culminated in a better understanding of Zn in the agricultural production systems of WA. The distribution and correction of Zn deficiency is now predictable for the many soil types and cropping systems of WA. Accurate identification of Zn deficiency for a range of crop and pasture species by plant analyses, typically the youngest mature leaf, is now possible for local conditions. With the calibration of the DTPA Zn soil test for soils of WA, particularly for wheat the major crop species grown in WA, prognosis of potential Zn deficiency can now be predicted before the appearance of Zn deficiency or loss in plant production.

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23

Brennan, Ross F. "Zinc application and its availability to plants". Brennan, Ross F. (2005) Zinc application and its availability to plants. PhD thesis, Murdoch University, 2005. http://researchrepository.murdoch.edu.au/436/.

Texto completo da fonte

Resumo:

Globally, low zinc (Zn) soils are widespread, but one of the largest expanses of such soils is in south west Australia (WA). Early Zn research in the region determined how much fertiliser Zn was required for profitable production of spring wheat (Triticium aestivum L.) and subterranean clover (Trifolium subterraneanum L), the major crop and pasture species at the time. The research showed that Zn sulfate and ZnO were equally effective Zn fertilisers, but ZnO was cheaper and so was widely used. The research indicated that in the year of application, depending on soil type, between 0.5-1.5 kg Zn/ha provided adequate Zn for the production of wheat and subterranean clover. The length of time that a single application of Zn fertiliser remains fully effective in maintaining the production of crops and pasture in future years (residual value; (RV)) had not been determined. This knowledge of the RV of Zn fertilisers is required for soils of WA. The experiments that measured the RV of fertiliser Zn for spring wheat and subterranean clover form the bulk of this thesis. The soils in the region were also initially acutely phosphorus (P) deficient requiring the application of fertiliser P for profitable production. Single superphosphate was the P fertiliser initially used. It was manufactured locally using phosphate rock imported from Nauru and Christmas Islands. This phosphate rock also contained much Zn, and the single superphosphate manufactured from it contained 400-600 mg Zn/kg. At amounts of application needed to provide adequate P, the Zn-contaminated superphosphate also supplied about 90 g Zn/ha. Therefore, early field experiments measured the RV of ZnO applied to soil when single superphosphate was applied annually at >150 kg/ha. In these experiments, the RV of Zn was measured when different amounts of fertiliser nitrogen (N) was applied. This was because it has recently been very profitable to apply fertiliser N to wheat crops, which greatly increased grain yields and so may have increased the demand for Zn, thereby probably decreasing the RV of the original ZnO application. In these experiments, there were many nil-Zn plots. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. No Zn deficiency was detected for up to 23 years after applying ZnO while applying superphosphate at >150 kg/ha per year and for all amounts of N applied. Subsequently cheap imported DAP fertiliser was used for wheat crops instead of locally produced Zn-contaminated single superphosphate and urea. The imported DAP contained about 50 mg Zn/kg (1/12 that of single superphosphate). This new fertiliser strategy induced Zn deficiency in many wheat crops. This led to further field studies to determine the RV of ZnO fertiliser when DAP was applied. The experiments also included 2 Zn-contaminated single superphosphate treatments. In one, no ZnO was applied, and superphosphate was applied at >150 kg/ha per year to match the amount of P applied as DAP to the other treatments. The other treatment was the same, except 1.5 kg/ha Zn as ZnO was applied in the first year only. In subsequent years, freshly-applied ZnO amounts were applied to measure the RV of the original ZnO treatments relative to the fresh Zn treatment. Relative to freshly-applied Zn in each year, the RV of the original ZnO treatments decreased as the length of time that the Zn was in contact with soil increased. However, the rate of decline in the RV was also found to differ with soil type, and was affected by soil pH, clay and organic carbon content of soil, and in alkaline soils with the calcium carbonate content of soil. Parallel glasshouse studies measured the RV of Zn, as Zn sulfate, for wheat and subterranean clover, using many soils from WA and other Australian States. The glasshouse studies also showed that the rate of decline in the RV of the original Zn application varied markedly with soil type and was strongly influenced by soil pH, clay and organic carbon content of soil, and in the alkaline soils, the amount of calcium carbonate in soil. In the above studies, the RV of fertiliser Zn was measured relative to freshly-applied Zn using yield of plants (shoots and grain for wheat, shoots for clover), Zn content in shoots and grain, and soil test Zn using the ammonium oxalate and DTPA procedures. In addition, Zn concentration in young tissue and rest of shoots (glasshouse studies) and young tissue and whole shoots (field studies) was measured, and Zn concentration related to 90 % of the maximum yield (critical Zn in plant parts) was determined. The studies showed that the DTPA soil test procedure, together with soil pH, and clay and organic matter content of soil, was an accurate prognostic test for indicating when Zn deficiency was likely in the next clover or wheat crop. The study confirmed that young tissue (youngest fully expanded leaves) provided critical plant test values for diagnosing Zn deficiency in plants. The plant and soil tests for Zn are now used by commercial soil and tissue testing laboratories. When Zn deficiency was diagnosed early in field grown wheat, Zn sprays can be applied to the crop foliage to prevent or minimise decreases in grain yields at the end of the growing season. Zn sulfate and Zn chelate are the most widely used compounds. This thesis reports the results of a field study to compare the effectiveness of the two compounds when the spray was applied at two growth stages of wheat (Gs14; seedling growth and Gs24; tillering). In addition, Zn applied with the seed while sowing the wheat crop was also included. Zinc applied to the soil while sowing was the most effective treatment. Zn chelate was more effective as a spray than Zn sulfate when applied at the earlier growth stage, but Zn sulfate was cheaper, and both sprays were equally effective when applied at the later growth stage. Recently in the region, durum wheat (T. durum L.), narrow-leafed lupin (Lupinus angustifolius L.), yellow lupin (L. luteus L.), white lupin (L. albus L.), canola (Brassica napus L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.) and lentil (Lens culinaris Medik) were all increasingly grown in rotation with spring wheat. Consequently, the Zn requirement of the new crops was compared with the Zn requirements of spring wheat. Species requiring less Zn than spring wheat to produce the same relative yield were faba bean, chickpea, albus lupin and canola; species requiring more Zn were lentil and durum wheat. Spreadsheet models were developed to determine when re-application of fertiliser Zn was required for low and high production systems. Relative to freshly-applied Zn, the rate of decline in the RV of Zn applied in a previous year varied depending on the amount of Zn applied, time the Zn was in contact with soil since application, properties of the soil (soil pH, % clay, % organic carbon, % free calcium carbonate), plant species, and the amount of Zn removed in harvested grain or hay. The thesis has culminated in a better understanding of Zn in the agricultural production systems of WA. The distribution and correction of Zn deficiency is now predictable for the many soil types and cropping systems of WA. Accurate identification of Zn deficiency for a range of crop and pasture species by plant analyses, typically the youngest mature leaf, is now possible for local conditions. With the calibration of the DTPA Zn soil test for soils of WA, particularly for wheat the major crop species grown in WA, prognosis of potential Zn deficiency can now be predicted before the appearance of Zn deficiency or loss in plant production.

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Vaillant, Nathalie. "Effet du zinc sur la croissance, l'activité photosynthétique et la synthèse de métabolites secondaires chez différentes espèces de Datura : développement d'un procédé d'épuration des effluents urbains couplé à la production de plantes à intérêt pharmaceutique". Clermont-Ferrand 1, 2003. http://www.theses.fr/2003CLF1MM01.

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Willems, Glenda. "Characterisation of zinc and cadmium tolerance in Arabidopsis halleri". Lille 1, 2006. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/481f2da5-d398-40e2-b36f-2796fb68be85.

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Dans cette étude, nous avons développé une approche de type Quantitative Trait Loci (QTL) afin d'étudier le déterminisme génétique de la tolérance au zinc (Zn) et au cadmium (Cd) dans l'espèce Arabidopsis halleri A. Halleri (n = 8) est une espèce métallophyte distribuée sur des sites pollués et non pollués. La tolérance au Zn et au Cd étant constitutivement présentes dans l'espèce étudiée, nous avons développé une population de type backcross (BC 1) à partir d'un croisement interspécifique entre un individu A. Halleri, et un individu de l'espèce proche non tolérante A. Lyrata ssp. Petraea (n = 8). Une carte génétique constituée de 8 groupes de liaison, équivalents au nombre de chromosomes des deux espèces parentales a été construite. Nous avons identifié 3 QTLs pour la tolérance au Zn, ainsi que pour la tolérance au Cd. Le QTL majeur de la tolérance au Cd est également impliqué dans la tolérance au Zn. Nous proposons 3 gènes candidats pour la tolérance au Zn HMA4 (pompe à métaux), MTP1-A et MTP1-B (des transporteurs de Zn). HMA4 co-localise aussi avec le QTL majeur de la tolérance au Cd. Nous n'avons identifié aucun gène candidat potentiel pour les deux autres régions QTL de la tolérance au Cd. Vu la taille des intervalles de confiance associés aux régions QTLs (> 4 cM), nous ne pouvons actuellement pas confirmer avec certitude l'implication des gènes proposés ci-dessus dans la tolérance au Zn ou au Cd. Cependant, la localisation dans les zones QTL de ces gènes actifs dans l'homéostasie des métaux justifie aujourd'hui qu'ils fassent l'objet d'une étude plus approfondie en génomique fonctionnelle afin de déceler leur contribution exacte à la tolérance aux métaux lourds dans A. Halleri ainsi qu'en évolution moléculaire afin de rechercher par analyse du polymorphisme nucléaire d'éventuelles signatures de sélection. En vue de l'identification d'autres gènes potentiellement impliqués dans la tolérance au Zn, nous avons appliqué une deuxième stratégie consistant dans l'intégration des résultats obtenus dans une analyse transcriptomique et dans l'analyse QTL de la tolérance au Zn.

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Adele, Nyekachi Chituru. "Effects of metal speciation on metal plant dynamics in the presence of plant growth promoting bacteria". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/25414.

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Excessive metal deposition in soil is of major concern to the environment due to the toxicity of metals to animals and plants. Since metals do not degrade, reducing risk of exposure relies in either removing the metals from soil, or changing their speciation which leads to changes in bioavailability, mobility and toxicity. Plants have been shown to provide a cheap alternative to chemical methods for both removing and changing metal speciation, particularly when augmented with plant growth promoting bacteria. The focus of this thesis was to investigate whether the form (speciation) in which a metal contaminant is introduced to soil affects both plant health and the efficiency of metal remediation by the plant, using the well-known hyperaccumulator Brassica juncea (L.) Czern and zinc (Zn) as the metal contaminant. This study also examined the role of plant growth promoting bacteria in changing metal speciation, impact on metal toxicity and phytoremediation efficiency. Brassica juncea was grown in pots containing soil spiked with equal amounts (600 mg Zn kg-1) of soluble Zn (ZnSO4) and nanoparticulate ZnS and ZnO. Plant height, number of leaves, root length, plant biomass and chlorophyll content of Brassica juncea were used to assess Zn toxicity. Zn localisation and speciation in soil and plant tissues was studied using transmission electron microscopy (TEM), synchrotron micro-X-ray fluorescence elemental mapping (μXRF) and synchrotron X-ray absorption spectroscopy (XAS). Growth parameters showed that ZnSO4 was the most toxic form of Zn whilst ZnS and ZnO effects were not statistically different. These differences were linked to differences in Zn content in root and shoot biomass, which was higher in ZnSO4 treatments. Inoculation with Rhizobium leguminosarum and Pseudomonas brassicacearum enhanced plant growth, Zn concentration in plant biomass and translocation of Zn in all Zn treatments. XAS analysis showed that Zn speciation was altered in roots of plants inoculated with bacteria, with Zn cysteine as the most dominant form of Zn in all inoculated Zn treatments, suggesting a role for cysteine in ameliorating Zn toxicity. By also assessing Zn speciation changes across the soilrhizosphere- plant interface, this study established that Rhizobium leguminosarum modified Zn speciation at the rhizosphere. Through this thesis work, metal speciation is a major factor in determining the efficiency of metal phytoremediation and plant tolerance. Hence, this research provides useful information on Zn speciation which will contribute to effective implementation of Zn phytoremediation.

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Brennan, R. F. "Zinc application and its availability /". Access via Murdoch University Digital Theses Project, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050602.142302.

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Defiani, Made Ria. "Zinc requirements of rice at elevated CO2 /". [Richmond, N.S.W.] : Centre for Horticulture and Plant Sciences, University of Western Sydney, Hawkesbury, 1999. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030519.171711/index.html.

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Holloway, R. E. "Zinc as a subsoil nutrient for cereals /". Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phh7454.pdf.

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Nedic, Stanko. "Zinc oxide nanowire field effect transistors". Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708233.

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Ondrasik, William E. "Evaluation of Native Ohio Plants to Lead and Zinc Contaminated Soils". Youngstown State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1246554091.

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Ondrasik, William Eric. "Evaluation of native Ohio plants to lead and zinc contaminated soils /". Connect to resource online, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1246554091.

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Kisko, Mushtak. "Study of Physiological and molecular mechanisms underlying the co-regulation between phosphate and zinc homeostasis in plants". Thesis, Montpellier, SupAgro, 2018. http://www.theses.fr/2018NSAM0004/document.

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Chez les plantes, alors qu'il est clair que l'homéostasie des différents nutriments est fortement dépendante les uns des autres, ils sont généralement étudiés indépendamment les uns des autres. Étant donné la rareté des études antérieures évaluant la signification biologique de l'interaction de l'homéostasie des nutriments minéraux, on en sait très peu sur la base génétique et moléculaire de ces interactions. Au cours de ma thèse, nous avons progressé de manière significative vers une compréhension plus intégrative du problème et identifié les bases moléculaires et génétiques d'une interaction nutritive très importante et conservée: l'interaction du zinc et du phosphate, dans laquelle les gènes PHO1;H3 et Lyso PhosphatidylCholine (PC) AcylTransferase 1 (LPCAT1) jouent des rôles centraux. En combinant des approches de biologie systémique et de biologie fonctionnelle, nous avons identifié le module fonctionnel (quatre facteurs transcriptions) qui régule l'expression de PHO1; H3 en condition de carence en Zn. Suite à une étude de génétique d’association (GWAS) nous avons découvert un nouveau rôle du gène LPCAT1 dans l’accumulation du phosphate en conditions de carence en Zn, Ensuite, nous avons déterminé une voie moléculaire complète contrôlant l'expression de ce gène. Ce travail nous permis de révéler un lien fondamental entre le métabolisme des phospholipides et l'interaction homéostasie Pi-Zn, et de proposer un nouveau rôle pour Lyso-PC et PC dans le contrôle de l'interaction homéostasie macro- et micronutriments chez les plantes. Les résultats obtenus offrent une nouvelle perspective pour élabore des nouvelles stratégies pour améliorer l’accumulation de Pi dans les plantes via la modulation de la voie de signalisation de la carence en Zn
In plants, while it is clear the homeostasis of different nutrients is highly dependent on each other, they are usually studied independent of each other. Given the paucity of past studies assessing the biological significance of mineral nutrient homeostasis interaction, very little is known about the genetic and molecular basis of such interactions. During my thesis, we made significant progress in going towards a more integrative comprehension of the problem and identify the molecular and genetic bases for a highly important and conserved nutrients interaction: the interaction of zinc and phosphate. First, using the phosphate transporter PHO1;H3 as entry molecular point, and by combining system biology and functional genomics approaches we have identified the functional module (four transcription factors) that regulates the expression and activity of PHO1;H3 under Zn deficiency leading to control Pi accumulation in shoots. Second, following our discovery of Lyso PhosphatidylCholine (PC) AcylTransferase 1 (LPCAT1) using genome-wide association studies (GWAS), we determined complete molecular pathway controlling the expression of this gene. We further uncovered a fundamental link between phospholipid metabolism and Pi-Zn homeostasis interaction via LPCAT1, which lays the foundations to explore a new role for Lyso-PC and PC in control of macro- and micronutrients homeostasis interaction. Taken together, our discoveries offer a new perspective on how to improve Pi content in plants, as our findings suggests that modulating the Zn-deficiency signalling pathway might be a good and simple approach for that

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Thomas, Louise. "The effect of zinc deprivation on protein energy and zinc metabolism in man". Thesis, University of Aberdeen, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245359.

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Dietary zinc deficiency was induced in four healthy male volunteers. The diet used was high in phytate (phytate:zinc molar ratio 381) and the depletion period was preceded by a 3 day starvation period. In the depletion period, there was a significant decrease in plasma zinc and urinary zinc excretion. The subjects also adapted to the low zinc intake by decreasing the faecal excretion of zinc. One subject (No.2) developed clinical signs of zinc deficiency and also had the lowest plasma zinc concentration at the end of the depletion stage. Whole body protein turnover was assessed by an 8hr primed constant infusion of Li-[1-¹³C]leucine. Zinc deficiency had an effect on whole body protein turnover in only one subject (No. 2). In this subject, there was a decrease in leucine oxidation (71%), protein synthesis (31%) and degradation (39%). In this group as a whole, zinc depletion was associated with a significant decrease in urinary excretion of 3-methylhistidine. Zinc deficiency appeared to have no effect on substrate utilization. With regard to zinc kinetics, zinc deficiency was associated with a significant decrease in the size of the plasma zinc pool and a liver pool. There was also a decrease in the flux between these two zinc pools, and an increase in the fractional decay of zinc from the plasma pool to the liver pool. Two further studies were carried out. In 4 volunteers the effect of a 3 day starvation period on whole body protein turnover and zinc kinetics was investigated. There was a significant increase in leucine oxidation and in the size of a liver zinc pool. In 6 volunteers, the effect of phytate on zinc kinetics was investigated. The addition of phytate to the test meal, (phytate:zinc molar ratio 88) was associated with a decrease in the size of a liver zinc pool.

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Pokhrel, Lok R., Brajesh Dubey e Phillip R. Scheuerman. "Developmental Phytotoxicity of Silver and Zinc Oxide Nanoparticles to the Crop Plants". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2950.

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Lopes, Sílvia Ferreira. "Effect of zinc oxide nanoparticles in Daphnia magna". Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10258.

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Mestrado em Biologia Aplicada - Toxicologia e Ecotoxicologia
O rápido desenvolvimento da nanotecnologia com o consequente aumento na produção de nanopartículas e nanoprodutos oferece muitas oportunidades mas também muitos desafios. A nanotecnologia tem vindo a ser descrita como uma área multidisciplinar que visa desenvolver uma variedade de nanoparticulas para aplicações medicinais e industriais. As propriedades que trazem às nanoparticulas especial atenção – pequeno tamanho, elevada área de superfície e consequente elevado grau de reatividade – podem também torná-las potencialmente perigosas para a saúde humana e para o ecossistema. A avaliação dos potenciais riscos inerentes à exposição das nanoparticulas torna-se portanto uma investigação de prioridade antes que estas sejam aplicadas em produtos comerciais e libertadas para o ambiente. Os ambientes aquáticos (de água doce e marinho) são considerados como potenciais destinos das nanoparticulas libertadas para o ambiente através de fontes diretas e/ou indiretas, expondo assim os organismos aquáticos a elevados níveis de contaminação. As nanoparticulas de óxido de zinco (ZnO-NPs) são uma das nanoparticulas mais utilizadas numa vasta gama de produtos comerciais (ex: protetores solares, cosméticos e tintas) e a sua produção estima-se que irá continuar a aumentar nos próximos anos. Em consequência, o risco de contaminação aquática por parte destas nanoparticulas irá forçosamente aumentar. Estudos toxicológicos já demonstraram que as ZnO-NPs exercem efeitos tóxicos em vários organismos, como por exemplo, em crustáceos, algas e bactérias. Os efeitos tóxicos das nanoparticulas são complexos e podem estar dependentes de vários fatores, tais como, o organismo-teste, fatores abióticos (pH, salinidade, dureza da água e presença de matéria orgânica), propriedades físico-quimicas das nanoparticulas, processos de adsorção, presença de outros contaminantes, entre outros. Os objetivos principais deste trabalho consistiram em avaliar a toxicidade das ZnO-NPs com diferentes tamanhos (30 e 80-100 nm) no cladócero Daphnia magna e comparar estes efeitos com os homólogos de tamanho micrómetro (ZnO > 200 nm) e a forma iónica (ZnCl2). Os efeitos foram avaliados nos parâmetros de imobilização, inibição alimentar e reprodução. Os resultados mostraram uma relação dose-resposta entre o decréscimo dos parâmetros avaliados e a concentração das ZnONPs, ZnO de tamanho micrómetro e ZnCl2 testadas. De acordo com os resultados obtidos foi possível concluir que o ZnCl2 induziu maior toxicidade aguda para a D. magna. Contudo, para a reprodução e inibição alimentar, as nanoparticulas de ZnO mostraram ter um efeito mais tóxico. Foi observado igualmente que o tamanho das nanopartículas não influenciou a toxicidade do ZnO. Este estudo realça a importância de se estudarem os efeitos de nanoparticulas de diferentes tamanhos uma vez que este é um parâmetro-chave que deve ser considerado quando se pretende estudar a toxicidade de nanoparticulas para o ambiente.
The rapid development of nanotechnology with the consequent increase in the production of nanoparticles and nanoproducts presents many opportunities but also many challenges. Nanotechnology has been described as a multidisciplinary field that develops a variety of engineered nanoparticles (ENPs) for medical and industrial applications. The properties that bring to ENPs special attention for commercial products – small size, large surface area and consequently high degree of reactivity – can also make them potentially harmful for human and ecosystem health. Therefore, assessing the potential risks associated with exposure of ENPs should be considered a major research priority before they are applied in commercial products and released to the environment. Aquatic (freshwater and marine) environment act as potential destinations for the ENPs released to the environment through direct and/or indirect sources, thus exposing aquatic organisms to high levels of pollutants. Zinc oxide nanoparticles (ZnO-NPs) are one of the ENPs most applied in a wide range of commercial products (e.g., sunscreens, cosmetics and paints) and its production is estimated to continue to rise in the upcoming years. As a consequence, the risk of aquatic environment contamination by these ENPs will increase. Toxicological studies have already demonstrated that nanoscale ZnO exert toxic effects in several organisms, such as crustaceans, algae and bacteria. The toxic effects of ZnO-NPs can be complex and may be dependent of several factors such as organism tested, abiotic factors (pH, salinity, water hardness, presence of natural organic matter), physico-chemical properties of NPs, adsorption phenomena, presence of other pollutants in the same environment, among others.

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Pokhrel, Lok R., Brajesh Dubey e Phillip R. Scheuerman. "Potential Developmental Toxicity of Silver and Zinc Oxide Nanoparticles to the Terrestrial Plants". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/2952.

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Tadayyon, Ali, Sedigheh Beheshti e Mohammad Pessarakli. "Effects of sprayed humic acid, iron, and zinc on quantitative and qualitative characteristics of niger plant ( Guizotia abyssinica L.)". Taylor & Francis, 2017. http://hdl.handle.net/10150/626135.

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In order to investigate the effect of foliar application of organic fertilizer and micronutrients on quantitative and qualitative characteristics of Niger plant, a field experiment was conducted in a complete randomized block design with three replications at Shahrekord University Research Farm during the years 2013-2014. Treatments included three levels of humic acid (1, 3, and 6 liters of humic acid per hectare), iron (4 parts per million, ppm), zinc (4 parts per million, ppm) and control (without humic acid iron, and zinc). In this experiment, traits of the number of heads per plant, seeds number per head, 1000 seeds' weight, grain yield, and also oil and protein content were evaluated. The findings showed that foliar application of humic acid, zinc and iron resulted in a significant increase in all analyzed traits. The most significant plant response was obtained with the use of 6 liters humic acid per hectare, and the second most significant plant response was seen with the sprayed zinc treatment which was probably due to limited absorption and deficiency of these elements in the tested soil.

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Sakhatska, I. M. "Study of medicinal plants with sedative effect". Thesis, БДМУ, 2021. http://dspace.bsmu.edu.ua:8080/xmlui/handle/123456789/18909.

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Brocavich-Nielsen, Juliann M. "Effect of dietary zinc and copper on plasma zinc, copper, total cholesterol in young adult males". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040757/.

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Haghighi, Maryam, e Mohammad Pessarakli. "Copper and zinc uptake by celery plants grown on acidic soil amended with biosolids". Taylor & Francis, 2015. http://hdl.handle.net/10150/615105.

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For trace elements, such as copper (Cu) and zinc (Zn), the bioavailability of these elements, Cu and Zn, in biosolids is important because both are essential elements and both are potential contaminants when biosolids are land applied. A greenhouse study was conducted in factorial experiment based on a completely randomized design (CRD) with four replications on a soil treated with four rates of Cu (0, 50, 100, and 150 mg/kg) and four rates of Zn (0, 150, 300, and 450 mg/kg) on celery plants to investigate the distribution and mobility of these elements as well as growth and antioxidant changes of celery. The results of antioxidant changes were inconclusive due to irregular changes with Zn and Cu applications. However, generally the results show that Cu did not affect superoxide dismutase (SOD) or peroxidase (POD) activities in most of the treatments. On the other hand, Zn stimulated SOD and POD activities in most of the treatments. The photosynthesis rate decreased with the applications of Cu and Zn at the rates above 100 and 300 mg/kg and increased in low Cu concentration (50 mg/kg) compared to S (soil without biosolid).

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Tiwale, Nikhil. "Zinc oxide nanowire field effect transistors for sensor applications". Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268227.

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A wide variety of tunable physio-chemical properties make ZnO nanowires a promising candidate for functional device applications. Although bottom-up grown nanowires are producible in volume, their high-throughput device integration requires control over dimensions and, more importantly, of precise placement. Thus development of top-down fabrication routes with accurate device positioning is imperative and hence pursued in this thesis. ZnO thin film transistors (TFT) were fabricated using solution based precursor zinc neodecanoate. A range of ZnO thin films were prepared by varying process parameters, such as precursor concentrations and annealing temperatures, and then analysed for their optical and electrical characteristics. ZnO TFTs prepared from a 15 % precursor concentration and annealing at 700 $^\circ$C exhibited best device performance with a saturation mobility of 0.1 cm$^2$/V.s and an on/off ratio of 10$^7$. Trap limited conduction (TLC) transport was found to be dominant in these devices. A direct-write electron beam lithography (EBL) process was developed using zinc naphthenate and zinc neodecanoate precursors for the top-down synthesis of ZnO nanowires. Nanoscale ZnO patterns with a resolution of 50 nm and lengths up to 25 $\mu$m were fabricated. A linear mobility of 0.5 cm$^2$/V.s and an on/off ratio of $\sim$10$^5$ was achieved in the micro-FETs with 50 $\mu$m channel width. Interestingly, on scaling down the ZnO channel width down to 100 nm, almost two orders of magnitude enhancement in the linear mobility was observed, which reached $\sim$33.75 cm$^2$/V.s. Such increment in the device performance was attributed to the formation of larger grains and thus reduction in the grain-boundary scattering. Six volatile organic compounds (VOCs) were sensed at room temperature using the direct-write EBL fabricated ZnO devices under UV sensitisation. As the surface-to-volume ratio increases with the decreasing channel width (from 50 $\mu$m to 100 nm), sensing response of the ZnO devices becomes more significant. Ppm level detection of various VOCs was observed; with a 25 ppm level Anisole detection being the lowest concentration. Additionally, using 100 nm device, detection of 10 ppm NO$_2$ was achieved at room temperature. The sensing response towards NO$_2$ was found to be increased with UV illumination and sensor temperature. This led to exhibit $\sim$171 % sensing response for a 2.5 ppm level of NO$_2$.

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Tabbaa, Mahmmoud M. "Pyrithione Zinc effect on Cancer Cell Proliferation and Viability". Ohio University Art and Sciences Honors Theses / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1509614945218889.

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44

Meindre, Fanny. "Etudes structurales de la défensine AhPDF1 de la plante Arabidopsis halleri impliquée dans la tolérance au zinc". Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-01058780.

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Mon travail de thèse porte sur la protéine AhPDF1 de la plante Arabidopsis halleri. AhPDF1 est une défensine de 51 résidus, riche en cystéines qui participe à la défense de la plante en jouant un rôle antifongique. La défensine AhPDF1 possède 8 cystéines impliquées dans ses 4 ponts disulfure, elle présente un repliement en CSαβ. Des travaux récents sur AhPDF1 ont permis d'identifier une nouvelle fonction : la tolérance aux métaux lourds, en particulier la tolérance au zinc. L'objectif général du projet dans lequel s'intègre ma thèse est donc de comprendre, au niveau atomique et en lien avec l'état d'oxydation des cystéines, le mécanisme par lequel les défensines de plantes confèrent la tolérance au zinc. Dans une majeure partie de ma thèse j'ai travaillé à la production de la défensine AhPDF1 d'abord dans Escherichia coli puis dans Pichia pastoris. J'ai ensuite mis au point la synthèse chimique de la protéine AhPDF1 et optimisé l'étape la plus délicate, celle du repliement oxydatif. Après avoir produit la défensine AhPDF1 en quantité et qualité suffisante, j'ai réalisé son étude structurale par RMN. De plus cette structure m'a servi de base pour modéliser, par homologie, toutes les autres défensines actuellement identifiées d'Arabidopsis halleri et Arabidopsis thaliana. Enfin, j'ai appris à maîtriser les conditions qui permettent de conserver la protéine dans un état partiellement réduit et j'ai réalisé les premiers essais de chélation de la défensine avec le zinc.

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45

Turner, Gary Chandler. "Zinc Oxide MESFET Transistors". Thesis, University of Canterbury. Electrical and Computer Engineering, 2009. http://hdl.handle.net/10092/3439.

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Zinc oxide is a familiar ingredient in common household items including sunscreen and medicines. It is, however, also a semiconductor material. As such, it is possible to use zinc oxide (ZnO) to make semiconductor devices such as diodes and transistors. Being transparent to visible light in its crystalline form means that it has the potential to be the starting material for so-called 'transparent electronics', where the entire device is transparent. Transparent transistors have the potential to improve the performance of the electronics currently used in LCD display screens. Most common semiconductor devices require the material to be selectively doped with specific impurities that can make the material into one of two electronically distinct types – p- or n-type. Unfortunately, making reliable p-type ZnO has been elusive to date, despite considerable efforts worldwide. This lack of p-type material has hindered development of transistors based on this material. One alternative is a Schottky junction, which can be used as the active element in a type of transistor known as a metal-semiconductor field effect transistor, MESFET. Schottky junctions are traditionally made from noble metal layers deposited onto semiconductors. Recent work at the Canterbury University has shown that partially oxidised metals may in fact be a better choice, at least to zinc oxide. This thesis describes the development of a fabrication process for metal-semiconductor field effect transistors using a silver oxide gate on epitaxially grown zinc oxide single crystals. Devices were successfully produced and electrically characterised. The measurements show that the technology has significant potential.

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Chakauya, Ereck. "Effect of manipulating pantothenate biosynthesis in higher plants". Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614866.

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Hayes, Sarah. "Effects of Mineral Weathering and Plant Roots on Contaminant Metal Speciation and Lability in Arid Lead-Zinc Sulfide Mine Tailings at the Klondyke Superfund Site, Graham County, AZ". Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/196007.

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Historic mine tailings pose a significant health risk to surrounding ecosystems and communities because of high residual concentrations of contaminant metals. The initial tailings mineral assemblage, metal sulfides, silicates, and carbonates are unstable at earth surface conditions and undergo oxidative and proton-promoted weathering. The weathering of metal sulfides generally produces acid that, if not balanced by protonconsuming dissolution of silicates and carbonates, leads to progressive acidification. The Klondyke State Superfund Site in Graham County, Arizona contains high concentrations of Pb (up to 13 g kg⁻¹) and Zn (up to 6 g kg⁻¹), and remains unvegetated 50 years after mining cessation. Field-scale investigation revealed a wide range of pH (2.5-8.0) and plant-available (DTPA-extractable) metals in the near surface of the tailings pile. Four samples were chosen for in-depth characterization ranging in pH, as denoted by subscript, from 2.6 to 5.4. The mineral transformations occurring in these four samples were investigated using a variety of techniques and the data indicated an increase in tailings weathering extent with increasing acidification (decreasing pH). Lead speciation, studied by a combination of chemical sequential extraction and X-ray absorption fine structure (XAFS) spectroscopy, was found to vary with tailings depth. The principle lead-bearing mineral was plumbojarosite (PbFe₆(SO₄)₄(OH)₁₂), with smaller amounts of anglesite (PbSO₄) and lead-sorbed iron-oxide. Anglesite, the most bioavailable mineral form of Pb in the tailings, was found to accumulate at the tailings surface, which has important implications for health risks. Total Zn content decreased by an order of magnitude (from 6 to 0.4 g kg⁻¹) and showed a change in molecular speciation with decreasing pH. Zinc-rich phyllosilicates and Zn-containing manganese oxides predominate at high pH, whereas low pH samples contained principally Zn-sorbed iron oxides. One of the overarching goals of the project is to remediate the Klondyke site using phytostabilization to keep contaminant metals from eroding offsite either by wind or water transport mechanisms. However, the impacts of plant growth on metal bonding environment are unknown. To address that gap in knowledge, we have developed a technique for the study of root-microbe-mineral-metal interactions that occur in the rhizosphere, the volume of soil surrounding, and affected by, plant roots. This technique involves the conjunctive use of fluorescence in-situ hybridization, X-ray fluorescence elemental mapping, XAFS and Raman micro-spectroscopies, and electron microscopy on single roots. Manganese and iron root plaques collocalized with elevated Pb, Zn, and Cr demonstrate that the rhizosphere can affect metal speciation. Metal speciation is an important factor in determining metal bioavailability, and thus is critical for understanding the health risk associated with mine tailings. The results of this research provides site-specific information about Pb and Zn speciation, which will be used to evaluate the effectiveness of site remediation within the context of metal toxicity.

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Simon, Kathryn D. "Effect of cellular zinc concentration on glucocorticoid induced gene expression". Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-06062008-155344/.

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Berthelot, Charlotte. "Les endophytes bruns septés dans les sols pollués aux éléments traces métalliques (ETM) : caractérisation, effet sur les plantes et mécanismes de tolérance aux ETM". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0024/document.

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Le phytomanagement est une méthode de gestion de sites pollués basée sur la capacité des plantes à séquestrer les polluants. L’utilisation de symbiotes fongiques peut représenter un atout afin d’augmenter la production de biomasse. Les endophytes bruns septés (DSE) pourraient stimuler la croissance végétale et augmenter leur protection contre les éléments-traces-métalliques (ETM). Cette thèse se déroule dans le cadre du projet LORVER et vise à comprendre l’interaction « plantes-DSE-sols pollués ». A ces fins, des champignons DSE isolés de racines de peupliers issues de sols pollués par des ETM ont été caractérisés. Ils appartiennent aux genres Leptodontidium, Phialophora, Cadophora et Phialocephala. Trois de ces souches ont ensuite été inoculées à des plantes en présence d’ETM. Dans certains cas, la croissance végétale a été stimulée et une augmentation de la teneur en chlorophylles, en P et en K, ou une réduction de la teneur en Cd dans les parties aériennes ont été mises en évidence. Puis, la souche la plus efficace sur la croissance végétale, Cadophora sp. Fe06, a été utilisée dans un double inoculum avec une souche endomycorhizienne, chez du ray-grass en présence d’ETM. Cette association diminue la teneur en Cd dans les feuilles. Enfin, les mécanismes impliqués dans la tolérance aux ETM chez les DSE ont été examinés via le criblage d’une banque de mutants d’insertions aléatoires, et via l’étude du rôle de la mélanine. Ce travail met en évidence que l’utilisation de DSE, de part leur capacité à coloniser de nombreuses plantes dans différents sols et à stimuler leur croissance, pourrait représenter un atout considérable pour des opérations de phytomanagement
Phytomanagement is a handling method of contaminated sites based on the ability of plants to sequester pollutants. Fungi could favor plant growth in contaminated sites but were far less studied in the context of phytomanagement. Dark septate endophytes (DSE) were reported to improve plant tolerance against metallic trace elements (TE). The present work is part of the LORVER project and aims to understand the “plant-DSE-TE”. DSE were isolated from poplar roots growing on TE-contaminated soils and characterized. They belong to Leptodontidium, Phialophora, Cadophora and Phialocephala genera. Three strains were inoculated to birch and poplar in TE-contaminated soils. Leptodontidium sp. improved plant growth with an increase in chlorophyll, P and K concentrations, whereas Cadophora sp. decreased Cd concentration in shoots of birch. Then, Cadophora sp. Fe06, was used with an endomycorrhizal fungus, to co-inoculate ryegrass in a TE-polluted soil. The co-inoculation leads to the decrease of Cd concentration in shoots. Finally, the mechanisms involved in TE-tolerance by DSE were studied through the screening of a library of Leptondontidium sp. insertional random-mutants and an evaluation of the role of melanin against TE stress. The present work highlights the complexity of the interactions between DSE and plants under TE stress. These interactions were influenced by different parameters including plant species, DSE strains, and soil properties. Nevertheless, the ability of DSE to colonize a broad spectrum of plants in different soils and to promote plant growth, suggest that DSE could represent a substantial benefit for the fungus-assisted phytomanagement of polluted soils

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Kim, ChulHwan. "The effect of dietary zinc level upon the efficiency of vitellogenin synthesis by male quail". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040742/.

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