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Articoli di riviste sul tema "Plants, Effect of gibberellins on"
1
Wang, Bing, e Alan R. Langille. "Response of a Gibberellin-deficient Potato Mutant to Induction and Growth Regulators as a Working Model for Tuber Initiation". HortScience 42, n. 3 (giugno 2007): 540–43. http://dx.doi.org/10.21273/hortsci.42.3.540.
Testo completoAbstract (sommario):
To explore further the role endogenous gibberellins play in the formation of the potato tuber, a gibberellin-deficient dwarf of Solanum tuberosum subsp. andigena (PI 281036) and its normal sibling were used in this study. Because gibberellins are known to be elevated and to affect tuber formation negatively when potato plants are grown under long day conditions, test plants were first grown in a growth chamber under conditions that did not favor tuberization (noninducing conditions). The stem apices of dwarfs received weekly applications of a 100-ppm gibberellic acid (GA3) solution to achieve growth similar to that of normal plants. When the requisite height was achieved, five dwarfs and five normal sibs were treated to foliar runoff with a 100-ppm GA3 solution, and a like number of these plants received a control spray of distilled water. These plants were then placed in a growth chamber adjusted to inducing conditions for tuber initiation. An additional five dwarfs and five normal sibs were sprayed with 600 ppm paclobutrazol (PB), a gibberellin inhibitor, and a similar number of plants received a distilled water control spray. This group of plants was returned to the noninducing chamber. After 1 week, plants were removed from their respective growth chambers and divided into two-node apical, medial, and basal leaf-bud cuttings. Basal buds of the cuttings were buried in moist potting mix in a mist chamber with a 16-hour photoperiod. Rhizome and tuberization responses were evaluated after 3 weeks. The experiment was repeated and results combined for statistical treatment. Orthogonal contrasts revealed that apical cuttings from normal donor plants produced rhizomes only under noninducing conditions or when treated with GA3. No rhizomes formed on apical cuttings from normal plants growing under inducing conditions (favoring tuberization) or noninduced plants receiving PB (a gibberellin inhibitor). For apical dwarf tissues, there were no effects of treatments on rhizome production, except for the PB treatment, which resulted in shorter rhizomes. Tuberization was observed in apical tissues of induced and noninduced dwarfs, which lack the ability to synthesize gibberellin, but only in induced cuttings of normal sibs. Noninduced dwarf cuttings tuberized as well as those from normal plants receiving the antigibberellin treatment. Tuber weights from induced apical cuttings of dwarfs and normal sibs were not significantly different. These results support the significant role played by gibberellins in tuber formation.
2
Mignolli, Francesco, Graciela Beatriz Rojas e María Laura Vidoz. "Supraoptimal ethylene acts antagonistically with exogenous gibberellins during Solanum lycopersicum (Solanaceae) hypocotyl growth." Boletín de la Sociedad Argentina de Botánica 51, n. 2 (15 giugno 2016): 235–42. http://dx.doi.org/10.31055/1851.2372.v51.n2.14836.
Testo completoAbstract (sommario):
In many plant species, ethylene and gibberellins interact to regulate plant growth and development. In some cases, these hormones can act in a synergistic way whereas in others they can be antagonistic. To date, the control of hypocotyl elongation by ethylene and gibberellins has been poorly explored in tomato. In this paper, we report that, application of exogenous ethylene to tomato seedlings or high endogenous ethylene production, as in the epinastic mutant, strongly prevent the effect of gibberellic acid (GA3) application. Moreover, constitutive activation of gibberellin signal in a DELLA deficient mutant is not able to counteract the inhibitory effect of ethylene on hypocotyl elongation, suggesting that ethylene acts independently from DELLA-mediated gibberellin response. Interestingly, when ethylene perception is blocked, the GA3 promotive effect on hypocotyl length is less effective, indicating that the presence of a basal level of ethylene could synergistically enhance hypocotyl growth. Taken together, these observations may suggest that, in tomato, supraoptimal concentrations of ethylene are able to antagonize gibberellin effect but normal levels seem to promote gibberellin-induced hypocotyl elongation.
3
Wiseman, Nadine J., e Colin G. N. Turnbull. "Effects of photoperiod and paclobutrazol on growth dynamics of petioles in strawberry (Fragaria × ananassa)". Functional Plant Biology 26, n. 4 (1999): 353. http://dx.doi.org/10.1071/pp98001.
Testo completoAbstract (sommario):
Petiole elongation of strawberry plants (Fragaria × ananassa) is modified by photoperiod, and gibberellins may mediate this response. To test the relationship further, we measured petiole growth dynamics under short and long days, in comparison with responses to paclobutrazol, which reduces gibberellin biosynthesis. Growth rate in short days was lower after 2 days, and at its maximum was 60% of long-day controls. Petiole length at maturity was 75%, and was accounted for primarily by decreased cell length. Subsequent leaves showed similar patterns, but in the third leaf, cell number was also reduced. Petiole growth rate after treatment with paclobutrazol (5 mg plant–1) was maximal at 2 days, 44% of the control maximum at day 7. Mature length was 30% of controls, again due to reduced cell length. Second leaves had even more severely reduced growth rates. Increasing paclobutrazol concentration over the range 0.025–1.0 mg progressively reduced growth, but a gibberellin-independent component accounted for 20% of elongation. Effects of combined paclobutrazol and photoperiod treatments were additive. The normal short-day response therefore occurred in paclobutrazol-treated plants with already slowed growth and reduced capacity for gibberellin synthesis. We conclude that assessment of the function of gibberellins requires direct measurement of gibberellins in petioles during growth.
4
Han, Jennifer, Jan E. Murray, Qingyi Yu, Paul H. Moore e Ray Ming. "The Effects of Gibberellic Acid on Sex Expression and Secondary Sexual Characteristics in Papaya". HortScience 49, n. 3 (marzo 2014): 378–83. http://dx.doi.org/10.21273/hortsci.49.3.378.
Testo completoAbstract (sommario):
The vegetative forms of male (XY), female (XX), and hermaphrodite (XYh) papaya (Carica papaya L.) plants are phenotypically identical. However, the flower and inflorescence morphology of each sex type is unique. Gynodioecious varieties SunUp, SunUp Diminutive mutant, and dioecious AU9 were used to test the response of papaya to gibberellic acid (GA3). Exogenous applications of GA3 on female and hermaphrodite flowers of papaya did not yield any sex reversal phenotype but caused a significant increase in peduncle elongation and inflorescence branch number in all treated plants. An increase in flower number was seen in females but not hermaphrodites or males. There was an increase in plant height for all treated plants except SunUp Diminutive mutant, suggesting that the mechanism causing the dwarf phenotype is independent of gibberellins. Gibberellin metabolism genes were identified in the papaya genome, none of which mapped to the sex-determining region of either the male- or hermaphrodite-specific region of papaya Y or Yh chromosome. We hypothesize that a transacting regulatory element that enhances gibberellin biosynthesis plays a role in the extreme length of the male papaya peduncle.
5
Sabovljevic, Aneta, Marko Sabovljevic e D. Grubisic. "Gibberellin influence on the morphogenesis of the moss Bryum argenteum Hedw. in in vitro conditions". Archives of Biological Sciences 62, n. 2 (2010): 373–80. http://dx.doi.org/10.2298/abs1002373s.
Testo completoAbstract (sommario):
The moss Bryum argenteum Hedw. was treated with gibberellins as well as some inhibitors of gibberellin biosynthesis in order to investigate their influence on B. argenteum morphogenesis. Generally, gibberellins have not been chemically identified in bryophytes, while other groups of classical phytohormones (auxins, cytokinins, abscisic acid and ethylene) have been chemically identified in these plants. The in vitro culture of the moss Bryum argenteum was established from sterilized spores. The apical shoots of untreated gametophytes grown in vitro were used to investigate the influence of different substances on secondary protonema and on the growth and multiplication of the gametophytes. B. argenteum reacts differently to the growth regulators applied. Both gibberellins applied in vitro (GA3 and GA7) have a positive effect on B. argenteum morphogenesis. Shoot multiplication was negatively affected by three tested growth retardants (ancymidol, BX-112 and chlorocholine chloride), while these substances did not have such strong effects on the moss protonema development.
6
Jaques, Lanes B. A., Ivan R. Carvalho, Vinícius J. Szareski, João R. Pimentel, Cristian Troyjack, Simone M. Dellagostin, Mayara T. Mendonça et al. "Gibberellic Acid Utilization in Seeds and Plants of Beans: Effect on Growth and Seeds Physiological Quality". Journal of Agricultural Science 11, n. 2 (15 gennaio 2019): 541. http://dx.doi.org/10.5539/jas.v11n2p541.
Testo completoAbstract (sommario):
The growth regulators from gibberellins, when applied on plants, might improve physic and physiological features, stimulate cell division and elongation, this study aimed at evaluating the influence of gibberellic acid doses applied exogenously on bean crop through seed treatment, and analyzing its effects on morphological attributes of seedlings and physiological quality of the seeds produced. The experimental design was completely randomized design, with treatments corresponding to the doses: zero (distilled water only), 50, 100 and 200 mg L-1, arranged in four replicates. The use of gibberellic acid in bean seeds did not result in changes on the number of leaves, leaf area, dry mass of leaves and stem. Applications of foliar gibberellic acid potentiated stem height and root dry mass of seedlings.
7
Zhang, L., S. Rajapakse, R. E. Ballard e N. C. Rajapakse. "Light Quality Regulation of Gene Expression in Chrysanthemum". HortScience 33, n. 3 (giugno 1998): 446c—446. http://dx.doi.org/10.21273/hortsci.33.3.446c.
Testo completoAbstract (sommario):
A major part of Clemson light quality research program focuses on understanding the mechanisms of plant growth alteration under spectral filters. We have extended this research to understand the molecular basis for plant height control by spectral filters. From the whole plant research we have found that gibberellins (GA) play a key role in height control under spectral filters. However, it is not clear whether an alteration of endogenous gibberellin levels or a change in sensitivity to gibberellins is causing the observed effects. Since gibberellins are a key hormone in cell expansion and flower development, an understanding of gibberellin regulation and metabolism under spectral filters is critical for the control of height and flowering of plants grown under these filters. For the molecular study, we have selected the gene that code for enzyme GA 20-oxidase, one of the key enzymes involved in producing functional GAs in the mevalonic acid pathway. GA 20-oxidase is thought to be a site of regulation of GA synthesis by the environment. We are currently studying the regulation of the expression of this gene by light quality using Northern analysis. Results from temporal and tissue specific regulation of chrysanthemum plants grown under CuSO4 filters will be presented.
8
Miceli, Alessandro, Alessandra Moncada, Leo Sabatino e Filippo Vetrano. "Effect of Gibberellic Acid on Growth, Yield, and Quality of Leaf Lettuce and Rocket Grown in a Floating System". Agronomy 9, n. 7 (16 luglio 2019): 382. http://dx.doi.org/10.3390/agronomy9070382.
Testo completoAbstract (sommario):
Gibberellins (GAs) are growth hormones strongly involved in a wide variety of physiological activities. Currently, gibberellins are commercially used to enhance phenotypic characteristics, earliness, and productivity of many vegetable and ornamental crops. In this work, the efficacy of supplementation of low levels of gibberellic acid (0, 10−8, 10−6, and 10−4 M GA3) through the mineral nutrient solution of a floating system on yield and quality of leaf lettuce and rocket plants was tested. The marketability of plants was lost when 10−4 M GA3 was added to the mineral nutrient solution. This study demonstrated that the addition of 10−4 M GA3 exceeded the acceptable threshold for use in hydroponics production systems. Below the concentration of 10−4 M, the presence of GA3 in the mineral nutrient solutions (MNS), especially at 10−6 M GA3, stimulated plant growth and enhanced the yield. Various morphological and physiological traits were enhanced by GA3 treatments (biomass accumulation, leaf expansion, stomatal conductance, water use efficiency (WUE), Nitrogen use efficiency (NUE), etc.), with superimposable trends in both lettuce and rocket. The addition of 10−6 M GA3 to the nutrient solution of a hydroponic floating system can promote growth and quality of lettuce and rocket plants.
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Harkess, Richard L., e Robert E. Lyons. "Gibberellin- and Cytokinin-induced Growth and Flowering Responses in Rudbeckia hirta L." HortScience 29, n. 3 (marzo 1994): 141–42. http://dx.doi.org/10.21273/hortsci.29.3.141.
Testo completoAbstract (sommario):
BA and GA4+7, were applied to vegetative, mature Rudbeckia hirta plants at the beginning of long days (LD). There were no synergistic effects, but BA inconsistently affected branching and had no effect on flowering. Floral initiation of the terminal inflorescence was promoted by GA4+7, although axillary inflorescences were not. Increasing GA4+7 levels decreased the time to terminal inflorescence anthesis. However, the interval between the terminal and second axillary inflorescence anthesis was increased. The net result was no significant effect on the time to second axillary inflorescence anthesis. Gibberellins may enhance the LD effect on the apical meristem of Rudbeckia, but axillary meristems, which initiate later, remained unaffected. Chemical names used: benzyladenine (BA), gibberellin4+7, (GA4+7).
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da Silva, Gustavo Cabral, Ivan de-la-Cruz-Chacón, Ana Beatriz Marques Honório, Bruna Cavinatti Martin, Marília Caixeta Sousa, Felipe Girotto Campos, Carmen Sílvia Fernandes Boaro e Gisela Ferreira. "Temperature and GA3 as Modulating Factors in the Biosynthesis of Alkaloids during Imbibition and Early Development of Annona x atemoya Mabb. cv. ‘Gefner’ Seedlings". Horticulturae 8, n. 9 (26 agosto 2022): 766. http://dx.doi.org/10.3390/horticulturae8090766.
Testo completoAbstract (sommario):
Alkaloids are products of the specialized metabolism of plants and temperature is a factor capable of modulating their biosynthesis. Species of the Annonaceae family biosynthesize alkaloids and present dormancy in their seeds, which can be overcome with the use of gibberellins. Therefore, the aim of this work was to evaluate whether temperature variations and the use of gibberellin in seeds affect the production of alkaloids during germination and early development of Annona x atemoya Mabb. cv. ‘Gefner’ seedlings. Results showed that the temperature of 30 °C associated with imbibition in water caused an increase in the production of total alkaloids and liriodenine and that the use of gibberellin decreased production. In addition, it was possible to identify the presence of nine other alkaloids with organ-specific distribution. The presence of none of them was induced by the effect of temperature or gibberellic acid. Therefore, it could be concluded that temperature variation and the use of GA3 alter the biosynthesis of alkaloids, with high temperature causing increased concentration, but the use of GA3 reducing production.
Tesi sul tema "Plants, Effect of gibberellins on"
1
Darwiche, Amal Omar 1964. "Effect of cytokinin, gibberellin, and nitrogen applications on the growth of eldarica pine seedlings". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276979.
Testo completoAbstract (sommario):
A greenhouse experiment was conducted over a ninety day period to test the effect of different nitrogen fertilizer regimes and several application rates of compounds with gibberellin and cytokinin activity (GA4/7 and BA, respectively) on the growth and development of Pinus brutia var. eldarica. Nitrogen produced no significant effects and this was attributed to its abundance in the potting medium, to begin with. All levels of growth regulators used showed a highly significant effect on vegetative development. A reduction in root collar diameter, shoot elongation, needle nitrogen content and oven-dry weight, was observed, especially when the medium and high hormonal rates were used. Phytotoxicity increased with the increase in concentration of both chemicals. Ba induced a proliferation of adventitious buds along the stem of saplings, but this was accompanied with rapid new top growth and branching at the top only when BA was applied in conjunction with GA4/7.
2
Bezuidenhout, Johannes Jacobus. "Elucidating the dual physiological induced effect of gliotoxin on plants / Johannes Jacobus Bezuidenhout". Thesis, North-West University, 2011. http://hdl.handle.net/10394/6945.
Testo completoAbstract (sommario):
Fungi and Oomycetes represent the two most important groups of eukaryotic plant pathogens. Besides chemical and physical control of these pathogens, biological control is an approach enjoying increasingly more focus. One of the biological agents increasingly employed in biological control of plant pathogenic fungi is ironically the fungus Trichoderma, more specifically Trichoderma harzianum. Besides control of the fungal plant pathogens, another interesting aspect observed when plants are treated with Trichoderma harzianum are effects such as complete and even stand of plants, faster seed germination, increases in plant height and overall enhanced plant growth. Though there have been various studies on this effect, almost no research has yet been conducted to elucidate the mechanism by which these effects occur. In particular, effects such as faster seed germination suggest that Trichoderma harzianum produces a metabolite that may mimic the plant growth hormone gibberellic acid. Through an evaluation of the various metabolites produced by Trichoderma harzianum; gliotoxin seemed structurally most similar to gibberellic acid. To verify that gliotoxin can indeed serve as an analogue for gibberellic acid and elicit similar physiological responses in plants, a two–pronged approach was followed.
Firstly, molecular similarity evaluation through common pharmacophore evaluation was conducted, followed by docking simulations into the recently discovered receptor for gibberellic acid. Common pharmacophore evaluation between gibberellic acid and gliotoxin showed successful alignment of gliotoxin into the gibberellic acid based pharmacophore space. Furthermore, docking simulations further strengthened this by the similarity in docking scores calculated and the similar poses of the ligands (gliotoxin and gibberellic acid) in the receptor space. However, similarity in pharmacophore alignment and docking simulation results only suggest that gliotoxin should be able to occupy the receptor space, but it is not a guarantee that similar physiological responses will be elicited.
In the second part of the project, the ability of gliotoxin to elicit similar physiological responses in plants to gibberellic acid was investigated. For this, a–amylase induction; plant emergence and height; and chlorophyll fluorescence were compared for both gliotoxin and gibberellic acid treatments. In terms of a–amylase induction, gliotoxin was able to induce production of the enzyme as visualised by starch–containing native gel electrophoresis (zymograms). Gliotoxin induced the strongest response at a 10–6 M dilution which is typically the range expected for hormones in biological systems in de–embryonated seeds of Phaseolus vulgaris. Gibberellic acid was able to induce the strongest response at a 10–7 M dilution. In essence, similar physiological responses were observed. In terms of plant emergence and plant height, treatment with gliotoxin or gibberellic acid resulted in plant emergence a day earlier than the untreated control. However, even though there were slight differences in plant height favouring the gliotoxin or gibberellic acid treated plants, the differences were not statistically significant. Thus, in this regard similar responses were again observed for both gliotoxin and gibberellic acid treatments. In the final evaluation the effect of gliotoxin and gibberellic acid treatments on the chlorophyll fluorescence of mature plants was investigated. Overall, both gliotoxin and gibberellic acid elicited beneficial effects on plant vitality, expressed through PI(Abs) with the gliotoxin treatment performing better than the equivalent gibberellic acid treatment.
Overall, the physiological tests demonstrated that gliotoxin can indeed elicit similar positive physiological responses to gibberellic acid in Phaseolus vulgaris. Furthermore the test used in this project can serve as a standard evaluation bench for screening for gibberellic acid analogues on a laboratory scale before larger scale field trials are considered.Thesis (Ph.D. (Microbiology))--North-West University, Potchefstroom Campus, 2012.
3
Buzzello, Gederson Luiz. "Uso de reguladores no controle do crescimento e no desempenho agronômico da cultura da soja cultivar CD 214 RR". Universidade Tecnológica Federal do Paraná, 2010. http://repositorio.utfpr.edu.br/jspui/handle/1/240.
Testo completoAbstract (sommario):
O acamamento de plantas provoca perdas significativas no rendimento de grãos da
cultura da soja e por isso estratégias de manejo para minimizar o acamamento são
importante necessidade na agricultura atual. O objetivo desse trabalho foi estudar
ação de reguladores de crescimento vegetal sobre o acamamento e outras características agronômicas da cultivar de soja CD 214 RR, em épocas de semeadura e densidades distintas. Foram conduzidos dois experimentos na Estação Experimental da Universidade Tecnológica Federal do Paraná, Campus Pato Branco. No primeiro experimento foram testados diferentes reguladores de
crescimento, sob concentrações distintas. O delineamento experimental foi inteiramente ao acaso com trinta e um tratamentos e quatro repetições. As quatro melhores combinações de reguladores/concentrações neste experimento foram utilizadas no segundo experimento. O segundo experimento foi conduzido em delineamento experimental de blocos ao acaso, com 3 repetições, em um esquema fatorial 5x3x3, em que o primeiro fator correspondeu às quatro combinações de
reguladores/concentrações selecionadas no primeiro experimento e, também, a
testemunha sem aplicação; o segundo fator correspondeu a três diferentes épocas
de semeadura (01 de novembro, 15 de novembro, e 11 de dezembro); o terceiro
fator correspondeu a três diferentes densidades de semeadura, em que a população
final para cada densidade foi de 200.000, 300.000 e 400.000 plantas ha-1. No primeiro experimento, foram avaliados o acamamento, injúria e estatura de planta, durante o desenvolvimento da cultura. No segundo experimento também foram avaliadas estas variáveis, somente ao final do ciclo da cultura. No primeiro experimento foram coletadas amostras de plantas em 0,45 m2, na área útil da parcela, para posterior determinação dos componentes do rendimento, no estádio R9. Uma amostra foi coletada no estádio R8, representada por 10 plantas por
parcela, em que foi obtido o índice de colheita e rendimento biológico aparente. Em
ambos os experimentos, no estádio R9 da cultura, houve a colheita do restante da
área útil da parcela, para determinação do rendimento de grãos. Os dados obtidos foram submetidos à análise de variância pelo teste F e foram comparados através de testes de comparação de médias. A relação entre variáveis dependentes e independentes foi ajustada através de regressão polinomial. Todos os tratamentos, de todos os seis grupos de reguladors vegetais foram eficientes em controlar o acamamento durante a maior parte do ciclo da cultura. O grupo do precursor de etileno ocasionou maior grau de fitotoxidade à cultura. Os compostos inibidores de auxina, inibidores de protox e bioestimulantes (AIB, GA3 e cinetina) apresentaram bons resultados na redução de estatura e do acamamento, apresentando grau de fitotoxidade leve e rápida recuperação dos sintomas de injúria. Os reguladores
trinexapac ethyl (312,5 g ha-1), IBA+GA3+cinetina (0,0375+0,0375+0,0675 g ha-¹) e lactofen (144 g ha-1) resultaram em rendimento de grãos mais elevados.
Isoladamente, as três concentrações de ethephon estudadas apresentam menor número de vagens por planta, menor peso de grão e menor rendimento de grãos. Os efeitos de fitorreguladores sobre o rendimento de grãos e componentes foram dependentes dos níveis em que estes foram aplicados sobre as plantas de soja. Onze tratamentos perfizeram o grupo que apresentou os rendimento de grãos mais elevados, entre eles os compostos por trinexapac ethyl (312,5 g ha-1),
IBA+GA3+cinetina (0,0375+0,0375+0,0675 g ha-1) e lactofen (144 g ha-1). Entre
todos os tratamentos, três concentrações de ethephon estudadas apresentam menor
número de vagens por planta, menor peso de grão e menor rendimento de grãos. O lactofen (144 g ha-1) promoveu maior redução em estatura, em plantas semeadas na primeira (01/11/08) e terceira época (11/12/08). Já o cloreto de mepiquat (250 g ha-1)foi mais eficaz na redução de estatura de plantas da terceira época de semeadura (11/12/08). O menor acamamento ocorreu na segunda época de semeadura, na densidade de 200.000 plantas ha-1. Considerando-se a média de densidades e
épocas de semeadura, os reguladores TIBA (6 g ha-¹), lactofen (144 g ha-¹) e
AIB+GA3+Cinetina (0,0375+0,0375+0,0675 g ha-¹) apresentaram o melhor desempenho na redução do acamamento. O maior rendimento de grãos de soja ocorreu na semeadura de 11 de dezembro, não sendo influenciado pela densidade de plantas nesta época. O menor rendimento de grãos em soja ocorreu na
semeadura do início de novembro, na densidade de 400.000 plantas ha-1. No
segundo experimento, as plantas de todos os tratamentos com regulador de crescimento não apresentaram sintoma de injúria na avaliação realizada no estádio R1 da cultura.The lodging of plants causes significant losses in grain yield of soybean and therefore management strategies to minimize the lodging are important in agriculture today. The aim of this work was to study the action of reducers of plant growth on lodging and other agronomic characteristics of soybean CD 214 RR at sowing dates and different densities. Two experiments were conducted at the Experimental Station of the Federal Technological University of Paraná, Pato Branco Campus. In the first experiment, testing different reducers of growth under different concentrations. The experimental design was completely andomized thirty-one treatments and four replicates. The four best combinations of concentrations in this experiment were used in the second experiment. The second experiment was conducted in a randomized block design with 3 replicates in a 5x3x3 factorial design, where the first factor corresponding to four combinations of concentrations selected in the first experiment (and also the control), the second factor corresponded to three different sowing dates (01 November, 15 November, and December 11), the third factor corresponded to three different plant densities in the final population for each density was 200.000, 300.000 and 400.000 plants ha-1. The first experiment examined the lodging, injury and plant height during the development of the culture. In the second experiment also evaluated these variables at the end of the cycle. In the first experiment samples were collected from plants in 0,45 m2 in each parcel, for later determination of yield components, the stage R9. A sample was collected at the R8 stage, represented by 10 plants per plot, which was obtained harvest index and biological yield apparent. In both experiments, the R9 stage of culture, there was the harvest of the remainder of each parcel to determine the yield. The data were subjected to analysis of variance by F test and were compared by means of comparison tests of means. The relationship between dependent and independent variables was adjusted by polynomial regression. All treatments in all six groups retardant were efficient in controlling the lodging for most of the crop cycle. The precursor of ethylene group caused a greater degree of phytotoxicity to the crop. The compounds of auxin inhibitors, protox and biostimulators (IBA, GA3 and kinetin) were able to reduce height and lodging, with slight degree of phytotoxicity and with rapid recovery of symptoms injury. Reducers trinexapac ethyl (312.5 g ha-1), IBA +GA3 +kinetin (0.0375, 0.0375 and 0.0675 g ha-¹) and lactofen (144 g ha-1) resulted in yield higher. Individually, the three concentrations of ethephon studied have a lower number of pods per plant, lower weight and lower grain yield. The effects of growth regulators on yield and components were dependent on the levels at which they are applied on the soybean plants. Eleven treatments accounted for the group the higher yield, among them the trinexapac ethyl (312.5 g ha-1), IBA GA3 kinetin (0.0375, 0.0375 and 0.0675 g ha-¹) and lactofen (144 g ha-1). Among all the treatments, the plants that received the three concentrations of ethephon studied have a lower number of pods per plant, lower weight and lower grain yield. The lactofen (144 g ha- 1) provided greater reduction in height, plants sown in the first (01/11/08) and third time (11/12/08). Since the chloride doses (250 g ha-1) was more effective in reducing plant height of the third sowing date (11/12/08). Smallest lodging occurred in the second sowing date, density of 200.000 plants ha-1. Considering the average densities and sowing dates, regulators TIBA (6 g ha-1), lactofen (144 g ha-1) and IBA +GA3+Kinetin (0.0375+0.0375+0.0675 g ha-1) showed the best performance in reducing lodging. The highest yield of soybean at sowing occurred on December 11 and is not influenced by the density of plants at this time. The lower yield in soybean planting occurred in early November, with a density of 400.000 plants ha-1. In the second experiment, plants of all treatments with growth retardant had no symptoms of injury in the assessment at the R1 stage of culture.
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Ertekin, Ozlem. "The Effect Of Indole Acetic Acid, Abscisic Acid, Gibberellin And Kinetin On The Expression Of Arf1 Gtp Binding Protein Of Pea (pisum Sativum L. Cv. Araka)". Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608902/index.pdf.
Testo completoAbstract (sommario):
ADP Ribosylation Factor 1 (ARF1) is a universal small GTP binding protein
which has an important role in vesicular trafficking between endoplasmic
reticulum and Golgi. ARF1 is a basic component of Coat Protein I (COPI) vesicles
which have functions in both formation of coatomer complex and recruitment of
cargo proteins. In this study, the expression ARF1 was analyzed in pea (P. sativum
L. cv. Araka) grown at different developmental stages. Because of the differential
hormonal levels at corresponding stages, the effects of hormones on ARF1
expression were also studied.
The results of present research show that ARF1 expression in embryos and 2 days
grown plants after germination is lower when compared to 6 days grown plants. In
order to see the hormonal effect, 3 weeks old plants were supplied with 50µM of each hormone for 3 times on alternate days. Protein extraction, cell fractionation,Western blot was carried out and immunoblot analysis was conducted with AtARF1 polyclonal antibodies. It was shown that, in pea shoots, abscisic acid and gibberellin increases the inactive GDP bound ARF1 by hydrolyzing ARF-GTP through activating ARFGTPase activating protein (ARF-GAP) or partially inhibiting ARF-Guanine Nucleotide Exchange Factor (ARF-GEF). In roots, ARF-GDP (cytosolic fraction), ARF-GTP (microsomal fraction) and total amount of ARF1 (13.000 x g supernatant fraction) were down regulated by ~11, ~19 and ~11 fold respectively with the application of gibberellin
and by ~11, ~7 and ~3 fold respectively with the application of abscisic acid
when compared to control plants. These results indicate the importance of plant hormones in the regulation of ARF1 in pea.
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Johnson, Kerry. "Photoperiod induction, Gibberellic acid, mulch and row cover effects on fresh cut flower production of three Rudbeckia hirta L. cultivars". Diss., Mississippi State : Mississippi State University, 2006. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
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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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Dickson, Ross L. "The effect of water stress, nitrogen and gibberellic acid on the phytotoxicity of post-emergent herbicides to Avena spp". Lincoln University, 1990. http://hdl.handle.net/10182/1283.
Testo completoAbstract (sommario):
A series of experiments was carried out on cultivated oat (Avena sativa L. cv Amuri) to examine the efficacies of fluazifop-butyl and glyphosate against water stressed plants, plants grown in low and high nitrogen and plants treated with gibberellic acid (GA₃). Avena sativa L. was used as a test plant and on completion of the experiments, further studies were carried out on the weed species wild oat (Avena fatua L.). In the laboratory, plants maintained at wilting point for five days before and nine days after spraying and treated with fluazifop-butyl (0.5 kg a.i./ha) appeared healthy 32 days after herbicide application, while plants supplied with water throughout the experiment were completely chlorotic/necrotic and had main stem detachment from within the leaf sheaths. In the field, plants maintained unirrigated until 14 days after spraying with fluazifop-butyl (0.25 kg a.i./ha) or glyphosate (0.18 kg a.i./ha) showed greater tolerance to the herbicides than plants irrigated regularly. Values for seed head yield for water stressed and irrigated plants, 45 days after applying fluazifop-butyl, were 66 g and zero g dryweight/m² respectively. Comparable values for glyphosate treated plants were 65 g and 25 g dryweight/m². Radiolabel studies indicated that in comparision with well watered plants, water stressed plants absorbed 20% less applied ¹⁴C-glyphosate. In addition, the proportion of absorbed ¹⁴C-glyphosate translocated from the treated leaf was 15% less under water stress conditions. Uptake of ¹⁴C-fluazifop-butyl was similar under well watered and water stress conditions and was 30-40% of that applied. The proportion of absorbed ¹⁴C-activity which was transported was very low, but was greater under well watered conditions (7.6%) than under water stress conditions (4.4%). Under well watered conditions in the laboratory and field, fluazifop-butyl (0.25 kg a.i./ha) and glyphosate (0.18 kg a.i./ha) were less toxic at low nitrogen than high nitrogen. For example, 34 days after spraying with fluazifop-butyl under laboratory conditions total plant dry weight was 1.51 g and 0.56 g at 1.0 mol/m³ and 10 mol/m³ applied nitrate respectively. As with soil water content, soil nitrogen content had no effect on uptake of fluazifop-butyl. However, the proportion of absorbed fluazifop-butyl which was translocated out of the treated lamina was greater under high nitrogen conditions (26.1 %) than under low nitrogen conditions (9.3%). Under laboratory conditions, addition of 200 µg GA₃to the leaf sheaths two days prior to spraying with fluazifop-butyl or glyphosate increased the efficacy of both herbicides at low nitrogen. Similarly, under field conditions application of GA₃ (0.21 kg/ha) two days prior to spraying with glyphosate increased the performance of the herbicide against Avena sativa L. growing in a nitrogen depleted soil. At harvest, seed head yield for GA₃ treated and non-treated plants was zero and 7.4 g dry weight/m² respectively. Experiments with Avena latua L. showed that this species was tolerant of fluazifop-butyl and glyphosate when grown in low water or low nitrogen conditions. Under water stress conditions, pre-treatment with GA₃ increased the phytotoxicity of fluazifop-butyl to Avena latua L. Similarily, GA₃ enhanced the phytotoxicity of glyphosate to Avena latua L. grown under low nitrogen conditions. Reduced performance of fluazifop-butyl under stress conditions involves a reduction in translocation of herbicide to meristems, but other factors are likely to be involved. It was concluded that for glyphosate, reductions in uptake and translocation of the herbicide are important factors causing reduced performance of this herbicide under stress conditions. Possible reasons for GA₃ enhancement of fluazifop-butyl and glyphosate activity under stress conditions are discussed and the potential of growth regulators as adjuvants is considered.
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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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Camut, Lucie. "Rôle des gibbérellines dans l’adaptation des plantes à la disponibilité en azote". Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAJ109.
Testo completoAbstract (sommario):
Les gibbérellines (GAs) sont des phytohormones régulant divers aspects de la croissance et du développement de la plante en réponse aux signaux endogènes et exogènes. Au niveau moléculaire, les GAs stimulent la dégradation des protéines DELLA, répresseurs nucléaires de croissance. L’azote (N), macronutriment essentiel au développement de la plante, représente un des facteurs les plus limitant pour la productivité agricole. Le nitrate (NO3-), principale source de N pour les plantes cultivées, est une molécule soluble dont la disponibilité varie dans l’espace et le temps. Depuis la Révolution Verte des années 1960, l’application d’engrais azotés et l’utilisation de variétés de céréales semi-naines (altérées dans leurs réponses aux GAs) à forts rendements ont permis d’augmenter significativement la productivité agricole. Récemment, il a été rapporté que des transporteurs NO3 - appartenant à la famille des NPF (NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY) étaient capables de transporter des GAs. Malgré les liens historiques et scientifiques établis entre les GAs et le NO3-, peu d’études se sont intéressées à l’effet du nitrate sur la biosynthèse, le transport et la signalisation GA chez les plantes. A l’aide d’approches génétiques, moléculaires et biochimiques réalisées chez Arabidopsis et le bl, ce travail de thèse démontre que le nitrate augmente la production et le transport acropète de GA12 (un intermédiaire de biosynthèse de GAs) et en conséquence, stimule la dégradation des répresseurs DELLAs. La diminution de l’abondance des DELLAs active la division cellulaire et donc la croissance de la plante. Par ailleurs, à l’aide de micro-greffes et de tests d’import de GAs réalisés dans des oocytes de Xenopus laevis, nous montrons que NPF2.12 et NPF2.13 facilitent le transport basipète de GA12 et du nitrate. Enfin, nous montrons que le transport acropète de GA12 est accru en réponse à une élévation de la température ambiante. Pris dans leur ensemble, ces résultats révèlent que la biosynthèse et le transport de GAs sont finement régulés en réponse à la disponibilité en nitrate et aux fluctuations de la température, permettant une croissance adaptée et optimale de la planteThe phytohormones gibberellins (GAs) regulate major aspects of plant growth and development in response to endogenous and exogenous signals. GAs promote growth by stimulating the degradation of nuclear growth repressing DELLA proteins. Nitrogen (N), a macronutrient essential for plant development, is one of the most limiting factors for agricultural productivity. Nitrate (NO3-) represents the main N source for cultivated plants but its availability fluctuates in both time and space due to its high solubility. Since the Green Revolution in the 1960’s, the use of N-fertilizers associated with high-yielding semi-dwarf cereal varieties, altered in GA responses, led to impressive yield increases. Recently, it has been reported that some NO 3 - transporters belonging to the NPF family (NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY), were able to transport GAs. Despite these observations, the effect of nitrate on GA biosynthesis, transport and signaling pathway is still unknown. Using genetics, molecular and biochemical approaches performed in Arabidopsis and wheat, this thesis work demonstrates that nitrate activates GA biosynthesis and GA12 transport (an inactive GA precursor), and as a consequence, DELLA protein degradation. The reduction in DELLA abundance increases cell division rate and thus plant growth. Moreover, through micrograftings and GA import assays in Xenopus laevis oocytes, we show that NPF2.12 and NPF2.13 facilitate the basipetal transport of GA12 and nitrate. Finally, we show that GA12 transport is enhanced by a small elevation of the ambient temperature. Altogether, these results reveal that GA biosynthesis and transport are tightly regulated in response to nitrate availability and temperature changes, enabling adaptive and optimal growth of the plant
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Voss, Joshua. "Forage adaptability trials for forage and seed production in Bolivia : effect of 5 herbicides on 7 native Utah forbs /". Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1639.pdf.
Testo completoLibri sul tema "Plants, Effect of gibberellins on"
1
Hall, J. Peter. Flower promotion in black spruce seedlings using gibberellins. St John's: Newfoundland Forestry Centre, 1986.
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2
Duckett, Catherine Mary. The effects of gibberellic acid on plant molecules. Norwich: University of East Anglia, 1992.
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3
Aftab, Tariq, a cura di. Auxins, Cytokinins and Gibberellins Signaling in Plants. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-05427-3.
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4
Big leaves for exotic effect. Lewes: Guild of Master Craftsman Publications, 2003.
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Photobiology of higher plants. Chichester: J. Wiley, 2004.
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6
N, Singh S., a cura di. Trace gas emissions and plants. Dordrecht, The Netherlands: Kluwer Academic, 2000.
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7
Mishra, S. K., e S. K. Mishra. Industrial pollution and plants. New Delhi: Ashish Pub. House, 1993.
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8
European Conference on Chemistry and the Environment (2nd 1984 Lindau, Bavaria, Germany). Air pollution and plants. Deerfield Beach, FL, USA: VCH Publishers, 1985.
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9
M, Orcutt David, e Hale Maynard G, a cura di. The physiology of plants under stress. New York: Wiley, 1996.
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10
Cunningham, J. D. Chernobyl: Its effect on Ireland. Dublin: Nuclear Energy Board, 1987.
Cerca il testo completoCapitoli di libri sul tema "Plants, Effect of gibberellins on"
1
Izumi, K., e H. Oshio. "Effects of the Growth Retardant Uniconazole-P on Endogenous Levels of Hormones in Rice Plants". In Gibberellins, 330–38. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4612-3002-1_32.
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2
Kamada, H., T. Ogasawara e H. Harada. "Effects of Gibberellin A3 on Growth and Tropane Alkaloid Synthesis in Ri Transformed Plants of Datura innoxia". In Gibberellins, 241–48. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4612-3002-1_23.
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3
Katsura, N., K. Takayanagi, T. Sato, T. Nishijima e H. Yamaji. "Gibberellin-Induced Flowering and Morphological Changes in Taro Plants". In Gibberellins, 370–77. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4612-3002-1_36.
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4
Junttila, O. "Gibberellins and the Regulation of Shoot Elongation in Woody Plants". In Gibberellins, 199–210. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4612-3002-1_19.
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5
Subroto, M. Ahkam, e Pauline M. Doran. "Production of steroidal alkaloids by hairy roots of Solanum aviculare and the effect of gibberellic acid". In Primary and Secondary Metabolism of Plants and Cell Cultures III, 93–102. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0237-7_2.
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Sponsel, Valerie M., e James B. Reid. "The effect of the growth retardant LAB 198 999 and its interaction with gibberellins A1, A3, and A20 in fruit growth of tall and dwarf peas". In Progress in Plant Growth Regulation, 578–84. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2458-4_69.
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Hooley, Richard. "Gibberellins: perception, transduction and responses". In Signals and Signal Transduction Pathways in Plants, 293–319. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0239-1_17.
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Ghassemi-Golezani, Kazem, e Samira Samea-Andabjadid. "Cytokinin Signaling in Plants Under Salt Stress". In Auxins, Cytokinins and Gibberellins Signaling in Plants, 189–212. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-05427-3_8.
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Ozga, Jocelyn A., Mark L. Brenner e Dennis Reinecke. "Characterization of the effect of seeds on gibberellin metabolism in pea pericarp". In Progress in Plant Growth Regulation, 591–96. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2458-4_71.
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Daramola, Olumide Samuel, Abraham Attah Shaibu e Vimal Kumar Semwal. "Iron Toxicity Tolerance in Rice: Roles of Auxins and Gibberellins". In Auxins, Cytokinins and Gibberellins Signaling in Plants, 337–51. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-05427-3_15.
Testo completoAtti di convegni sul tema "Plants, Effect of gibberellins on"
1
Kotova, L. M., e A. A. Kotov. "THE ROLE OF GIBBERELLINS IN CORRELATIVE INTERACTIONS BETWEEN THE SHOOTS OF PEA PLANTS". In The All-Russian Scientific Conference with International Participation and Schools of Young Scientists "Mechanisms of resistance of plants and microorganisms to unfavorable environmental". SIPPB SB RAS, 2018. http://dx.doi.org/10.31255/978-5-94797-319-8-443-447.
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Butler, A. D., C. C. Thomas, V. F. Medina e S. L. Larson. "The Effect of Plants on Lead Dissolution". In GeoFlorida 2010. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41095(365)277.
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Serag-Eldin, Mohamed A., e Mohammed A. Abdul Latif. "Magnus-Effect Rotors for Solar Chimney Power Plants". In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-31064.
Testo completoAbstract (sommario):
The paper proposes the use of spinning and rotating cylinders to replace the axial turbines of Solar Chimney power plants. A large number of circular cylinders are placed equidistant, on a circular track concentric with the solar chimney axis. The cylinders spin around their own axis while simultaneously rotating about the chimney axis. By virtue of the Magnus effect, Lift forces arise which create force components tangential to the track in the direction of motion of the cylinders; thus mechanical work is produced. Using CFD modeling, the paper analyzes the resulting flow pattern and presents the expected performance of the hypothetical design for different geometric parameters and operating conditions. It is demonstrated that the design is indeed promising, and worthy of further investigation and development. It is also revealed that good performance of the proposed rotor is highly dependent on the proper choice of operating parameters.
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Markova, Yu A., V. N. Nurminsky, I. S. Nesterkina, N. V. Ozolina, A. L. Tourskaya, V. A. Bybin, I. V. Klimenkov, L. A. Belovezovets e M. S. Tretyakova. "The effect of colchicine on microorganisms". In IX Congress of society physiologists of plants of Russia "Plant physiology is the basis for creating plants of the future". Kazan University Press, 2019. http://dx.doi.org/10.26907/978-5-00130-204-9-2019-279.
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Svistova, I. D., e N. M. Kuvshinova. "Phytosanitary effect of the plants – producers of sweet glycosides". In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.241.
Testo completoAbstract (sommario):
In the root zone of plants that accumulate sweet glycosides (honey stevia and naked licorice), a sharp decrease in the phytopathogenic potential of the soil was revealed without increasing its phytotoxic activity.
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Symochko, Lyudmyla, Ruslan Mariychuk, Olena Demyanyuk e Vitaliy Symochko. "Enrofloxacin in Agroecosystems: Uptake by Plants and Phytotoxical Effect". In 2019 International Council on Technologies of Environmental Protection (ICTEP). IEEE, 2019. http://dx.doi.org/10.1109/ictep48662.2019.8968989.
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Arifin, Zainal. "The effect of liquid NPK fertilizing on corn plants". In INTERNATIONAL CONFERENCE ON BIOLOGY AND APPLIED SCIENCE (ICOBAS). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5115617.
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"Study on Humidification and Cooling Effect of Garden Plants". In 2018 4th International Conference on Education, Management and Information Technology. Francis Academic Press, 2018. http://dx.doi.org/10.25236/icemit.2018.262.
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Efimova, M. V. "The protective effect of brassinosteroids in chloride salinity". In IX Congress of society physiologists of plants of Russia "Plant physiology is the basis for creating plants of the future". Kazan University Press, 2019. http://dx.doi.org/10.26907/978-5-00130-204-9-2019-168.
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HENRIQUE CABRAL DETTMER, PAULO, CARLOS OLAVO SLOTA OVELAR, MARCELO LUIZ NORILLER, JOSE JUNJI OTA e CLAUDIONOR FERNANDES CHAVES. "Computational and Experimental Modeling of Ejection Effect in Hydroelectric Plants". In 38th IAHR World Congress. The International Association for Hydro-Environment Engineering and Research (IAHR), 2019. http://dx.doi.org/10.3850/38wc092019-0379.
Testo completoRapporti di organizzazioni sul tema "Plants, Effect of gibberellins on"
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Friedman, Haya, Chris Watkins, Susan Lurie e Susheng Gan. Dark-induced Reactive Oxygen Species Accumulation and Inhibition by Gibberellins: Towards Inhibition of Postharvest Senescence. United States Department of Agriculture, dicembre 2009. http://dx.doi.org/10.32747/2009.7613883.bard.
Testo completoAbstract (sommario):
Dark-induced senescence could pose a major problem in export of various crops including cuttings. The assumption of this work was that ROS which is increased at a specific organelle can serve as a signal for activation of cell senescence program. Hormones which reduce senescence in several crops like gibberellic acid (GA) and possibly cytokinin (CK) may reduce senescence by inhibiting this signal. In this study we worked on Pelargonium cuttings as well as Arabidopsis rosette. In Pelargonium the increase in ROS occurred concomitantly with increase in two SAGs, and the increase persisted in isolated chloroplasts. In Arabidopsis we used two recentlydeveloped technologies to examine these hypotheses; one is a transcriptome approach which, on one hand, enabled to monitor expression of genes within the antioxidants network, and on the other hand, determine organelle-specific ROS-related transcriptome footprint. This last approach was further developed to an assay (so called ROSmeter) for determination of the ROS-footprint resulting from defined ROS stresses. The second approach involved the monitoring of changes in the redox poise in different organelles by measuring fluorescence ratio of redox-sensitive GFP (roGFP) directed to plastids, mitochondria, peroxisome and cytoplasm. By using the roGFP we determined that the mitochondria environment is oxidized as early as the first day under darkness, and this is followed by oxidation of the peroxisome on the second day and the cytoplast on the third day. The plastids became less oxidized at the first day of darkness and this was followed by a gradual increase in oxidation. The results with the ROS-related transcriptome footprint showed early changes in ROS-related transcriptome footprint emanating from mitochondria and peroxisomes. Taken together these results suggest that the first ROS-related change occurred in mitochondria and peroxisomes. The analysis of antioxidative gene’s network did not yield any clear results about the changes occurring in antioxidative status during extended darkness. Nevertheless, there is a reduction in expression of many of the plastids antioxidative related genes. This may explain a later increase in the oxidation poise of the plastids, occurring concomitantly with increase in cell death. Gibberellic acid (GA) prevented senescence in Pelargonium leaves; however, in Arabidopsis it did not prevent chlorophyll degradation, but prevented upregulation of SAGs (Apendix Fig. 1). Gibberellic acid prevented in Pelargonium the increase in ROS in chloroplast, and we suggested that this prevents the destruction of the chloroplasts and hence, the tissue remains green. In Arabidopsis, reduction in endogenous GA and BA are probably not causing dark-induced senescence, nevertheless, these materials have some effect at preventing senescence. Neither GA nor CK had any effect on transcriptome footprint related to ROS in the various organelles, however while GA reduced expression of few general ROS-related genes, BA mainly prevented the decrease in chloroplasts genes. Taken together, GA and BA act by different pathways to inhibit senescence and GA might act via ROS reduction. Therefore, application of both hormones may act synergistically to prevent darkinduced senescence of various crops.
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Kirova, Elisaveta. Effect of Nitrogen Nutrition Source on Antioxidant Defense System of Soybean Plants Subjected to Salt Stress. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, febbraio 2020. http://dx.doi.org/10.7546/crabs.2020.02.09.
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García Victoria, Nieves, Esteban Baeza Romero, Geert Franken, Silke Hemming e Gert Vletter. Effect of high scattering lamellae on growthand photosynthesis of young tomato plants : smart materials crop experiments. Bleiswijk: Stichting Wageningen Research, Wageningen Plant Research, Business Unit Greenhouse Horticulture, 2020. http://dx.doi.org/10.18174/564877.
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Palukaitis, Peter, Amit Gal-On, Milton Zaitlin e Victor Gaba. Virus Synergy in Transgenic Plants. United States Department of Agriculture, marzo 2000. http://dx.doi.org/10.32747/2000.7573074.bard.
Testo completoAbstract (sommario):
Transgenic plants expressing viral genes offer novel means of engendering resistance to those viruses. However, some viruses interact synergistically with other viruses and it is now known that transgenic plants expressing particular genes of one virus may also mediate synergy with a second virus. Thus, our specific objectives were to (1) determine if transgenic plants resistant to one virus showed synergy with another virus; (2) determine what viral sequences were essential for synergy; and (3) determine whether one of more mechanisms were involved i synergy. This project would also enable an evaluation of the risks of synergism associated with the use of such transgenic plants. The conclusion deriving from this project are as follows: - There is more than one mechanism of synergy. - The CMV 2b gene is required for synergistic interactions. - Synergy between a potyvirus and CMV can break natural resistance limiting CMV movement. - Synergy operates at two levels - increase in virus accumulation and increase in pathology - independently of each other. - Various sequences of CMV can interact with the host to alter pathogenicity and affect virus accumulation. - The effect of synergy on CMV satellite RNA accumulatio varies in different systems. - The HC-Pro gene may only function in host plant species to induce synergy. - The HC-Pro is a host range determinant of potyviruses. - Transgenic plants expressing some viral sequences showed synergy with one or more viruses. Transgenic plants expressing CMV RNA 1, PVY NIb and the TMV 30K gene all showed synergy with at least one unrelated virus. - Transgenic plants expressing some viral sequences showed interference with the infection of unrelated viruses. Transgenic plants expressing the TMV 30K, 54K and 126K genes, the PVY NIb gene, or the CMV 3a gene all showed some level of interference with the accumulation (and in some cases the pathology) of unrelated viruses. From our observations, there are agricultural implications to the above conclusions. It is apparent that before they are released commercially, transgenic plants expressing viral sequences for resistance to one virus need to be evaluated fro two properties: - Synergism to unrelated viruses that infect the same plant. Most of these evaluations can be made in the greenhouse, and many can be predicted from the known literature of viruses known to interact with each other. In other cases, where transgenic plants are being generated from new plant species, the main corresponding viruses from the same known interacting genera (e.g., potexviruses and cucumoviruses, potyviruses and cucumoviruses, tobamoviruses and potexviruses, etc.) should be evaluated. - Inhibition or enhancement of other resistance genes. Although it is unlikely that plants to be released would be transformed with HC-Pro or 2b genes, there may be other viral genes that can affect the expression of plant genes encoding resistance to other pathogens. Therefore, transgenic plants expressing viral genes to engender pathogen-derived resistance should be evaluated against a spectrum of other pathogens, to determine whether those resistance activities are still present, have been lost, or have been enhanced!
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Grumet, Rebecca, Rafael Perl-Treves e Jack Staub. Ethylene Mediated Regulation of Cucumis Reproduction - from Sex Expression to Fruit Set. United States Department of Agriculture, febbraio 2010. http://dx.doi.org/10.32747/2010.7696533.bard.
Testo completoAbstract (sommario):
Reproductive development is a critical determinant of agricultural yield. For species with unisexual flowers, floral secualdifferentation adds additional complexity, that can influenec productivity. The hormone ethylene has long, been known to play a primary role in sex determination in the Cucumis species cucumber (C. sativus) and melon (C. melo). Our objectives were to: (1) Determine critical sites of ethylene production and perception for sex determination; (2) Identify additional ethylene related genes associated with sex expression; and (3) Examine the role of environment ami prior fruit set on sex expression, pistillate flower maturation, and fruit set. We made progress in each of these areas. (1) Transgenic melon produced with the Arabidopsis dominant negative ethylene perception mutant gene, etrl-1, under the control of floral primordia targeted promoters [AP3 (petal and stamen) and CRC (carpel and nectary)], showed that ethylene perception by the stamen primordia, rather than carpel primordia, is critical for carpel development at the time of sex determination. Transgenic melons also were produced with the ethylene production enzyme gene. ACS, encoding l-aminocyclopropane-lcarboylate synthase, fused to the AP3 or CRC promoters. Consistent with the etr1-1 results, CRC::ACS did not increase femaleness; however, AP3::ACS reduced or eliminated male flower production. The effects of AP3:ACS were stronger than those of 35S::ACS plants, demonstratin g the importance of targeted expression, while avoiding disadvantages of constitutive ethylene production. (2) Linkage analysis coupled with SNP discovery was per formed on ethylene and floral development genes in cucumber populations segregating for the three major sex genes. A break-through towards cloning the cucumber M gene occurred when the melon andromonoecious gene (a), an ACS gene, was cloned in 2008. Both cucumber M and melon a suppress stamen development in pistillate flowers. We hypothesized that cucumber M could be orthologous to melon a, and found that mutations in CsACS2 co-segregated perfectly with the M gene. We also sought to identify miRNA molecules associated with sex determination. miRNA159, whose target in Arabidopsis is GAMYB[a transcription factor gene mediating response to10 gibberellin (GA)], was more highly expressed in young female buds than male. Since GA promotes maleness in cucumber, a micro RNA that counteracts GAMYB could promote femaleness. miRNA157, which in other plants targets transcription factors involved in flower development , was expressed in young male buds and mature flower anthers. (3) Gene expression profiling showed that ethylene-, senescence-, stress- and ubiquitin-related genes were up-regulated in senescing and inhibited fruits, while those undergoing successful fruit set up-regulated photosynthesis, respiration and metabolic genes. Melon plants can change sex expression in response to environmental conditions, leading to changes in yield potential. Unique melon lines with varying sex expression were developed and evaluated in the field in Hancock, Wisconsin . Environmental changes during the growing season influenced sex expression in highly inbred melon lines. Collectively these results are of significance for understanding regulation of sex expression. The fact that both cucumber sex loci identified so far (F and M) encode isoforms of the same ethylene synthesis enzyme, underscores the importance of ethylene as the main sex determining hormone in cucumber. The targeting studies give insight into developmental switch points and suggest a means to develop lines with earlier carpel-bearing flower production and fruit set. These results are of significance for understanding regulation of sex expression to facilitate shorter growing seasons and earlier time to market. Field results provide information for development of management strategies for commercial production of melon cultivars with different sex expression characteristics during fruit production.
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Citovsky, Vitaly, e Yedidya Gafni. Nuclear Import of the Tomato Yellow Curl Leaf Virus in Tomato Plants. United States Department of Agriculture, settembre 1994. http://dx.doi.org/10.32747/1994.7568765.bard.
Testo completoAbstract (sommario):
Tomato yellow leaf curl geminivirus (TYLCV) is a major pathogen of cultivated tomato, causing up to 100% crop loss in many parts of the world. In Israel the disease is well known and has an economic significance. In recent years viral symptoms were found in countries of the "New World" and since 1997, in Florida. Surprisingly, little is known about the molecular mechanisms of TYLCV interaction with the host plant cells. This proposal was aimed at expanding our understanding of the molecular mechanisms by which TYLCV enters the host cell nucleus. The main objective was to elucidate the TYLCV protein(s) involved in transport of the viral genomic DNA into the host cell nucleus. This goal was best served by collaboration between our laboratories one of which (V.C.) was already investigating the nuclear import of the T-DNA ofAgrobacterium tumefaciens, and the other (Y.G.) was studying the effect of TYLCV capsid protein (CP) in transgenic plants, hypothesizing its involvement in the viral nuclear entry. Three years of our collaborative work have provided signifcant data that strongly support our original hypothesis of the involvement of TYLCtr CP in viral nuclear import. Furthermore, our results have laid a foundation to study fundamental, but as yet practically unresolved, questions about the role ofthe host cell factors in the nuclear import of geminiviruses within their host plant. As a result, this research may lead to development of new approaches for plant protection based on control of TYLCV import to the host plant cell nucleus.
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Valverde, Rodrigo A., Aviv Dombrovsky e Noa Sela. Interactions between Bell pepper endornavirus and acute viruses in bell pepper and effect to the host. United States Department of Agriculture, gennaio 2014. http://dx.doi.org/10.32747/2014.7598166.bard.
Testo completoAbstract (sommario):
Based on the type of relationship with the host, plant viruses can be grouped as acute or persistent. Acute viruses are well studied and cause disease. In contrast, persistent viruses do not appear to affect the phenotype of the host. The genus Endornavirus contains persistent viruses that infect plants without causing visible symptoms. Infections by endornaviruses have been reported in many economically important crops, such as avocado, barley, common bean, melon, pepper, and rice. However, little is known about the effect they have on their plant hosts. The long term objective of the proposed project is to elucidate the nature of the symbiotic interaction between Bell pepper endornavirus (BPEV) and its host. The specific objectives include: a) to evaluate the phenotype and fruit yield of endornavirus-free and endornavirus-infected bell pepper near-isogenic lines under greenhouse conditions; b) to conduct gene expression studies using endornavirus-free and endornavirus-infected bell pepper near-isogenic lines; and c) to study the interactions between acute viruses, Cucumber mosaic virus Potato virus Y, Pepper yellow leaf curl virus, and Tobacco etch virus and Bell pepper endornavirus. It is likely that BPEV in bell pepper is in a mutualistic relationship with the plant and provide protection to unknown biotic or abiotic agents. Nevertheless, it is also possible that the endornavirus could interact synergistically with acute viruses and indirectly or directly cause harmful effects. In any case, the information that will be obtained with this investigation is relevant to BARD’s mission since it is related to the protection of plants against biotic stresses.
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Mudge, Christopher R., Kurt D. Getsinger e Benjamin P. Sperry. Simulated Herbicide Spray Retention on Floating Aquatic Plants as Affected by Carrier Volume and Adjuvant Type. U.S. Army Engineer Research and Development Center, giugno 2022. http://dx.doi.org/10.21079/11681/44540.
Testo completoAbstract (sommario):
Foliar delivery of herbicides is a common means for plant management in aquatic environments. Though this technique is decades old, little is known about vegetative spray retention relative to this application method. A more complete understanding of maximizing herbicide retention could lead to improved plant management while simultaneously decreasing pesticide load in aquatic environments. Therefore, outdoor mesocosm experiments were conducted in 2020 to evaluate the effect of adjuvant type on foliar spray retention in waterhyacinth [Eichhornia crassipes (Mart.) Solms]. Additionally, the effect of carrier volume on spray retention in waterhyacinth, waterlettuce (Pistia stratiotes L.), and giant salvinia (Salvinia molesta D.S. Mitchell) was documented. Spray deposition did not differ among the nine adjuvants tested; however, spray retention was reduced 6% to 11% when an adjuvant was excluded from the spray solution. The effect of carrier volume on spray retention in waterhyacinth, waterlettuce, and giant salvinia was also investigated. Decreases in spray retention were most sensitive to increased carrier volume in waterhyacinth, followed by giant salvinia and waterlettuce. Among species, spray retention potential, as determined by intercept estimates, was greatest in waterlettuce and giant salvinia regardless of carrier volume. Asymptotes estimates for waterhyacinth, waterlettuce, and giant salvinia were 33%, 46%, and 79% spray retention, respectively. In other words, spray retention was the lowest and remained relatively constant at these values for the high carrier volumes tested (935 and 1,870 L ha⁻¹), which were likely due to the presence of pubescence on leaves and flatter leaf architecture represented by waterlettuce and giant salvinia compared to the glabrous vertical leaves of waterhyacinth. Future research will evaluate these concepts under field condition.
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Weiss, David, e Neil Olszewski. Manipulation of GA Levels and GA Signal Transduction in Anthers to Generate Male Sterility. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7580678.bard.
Testo completoAbstract (sommario):
The original objectives of the research were: i. To study the role of GA in anther development, ii. To manipulate GA and/or GA signal transduction levels in the anthers in order to generate male sterility. iii. To characterize the GA signal transduction repressor, SPY. Previous studies have suggested that gibberellins (GAs) are required for normal anther development. In this work, we studied the role of GA in the regulation of anther development in petunia. When plants were treated with the GA-biosynthesis inhibitor paclobutrazol, anther development was arrested. Microscopic analysis of these anthers revealed that paclobutrazol inhibits post-meiotic developmental processes. The treated anthers contained pollen grains but the connective tissue and tapetum cells were degenerated. The expression of the GA-induced gene, GIP, can be used in petunia as a molecular marker to: study GA responses. Analyses of GIP expression during anther development revealed that the gene is induced only after microsporogenesis. This observation further suggests a role for GA in the regulation of post-meiotic processes during petunia anther development. Spy acts as a negative regulator of gibberellin (GA) action in Arabidopsis. We cloned the petunia Spy homologue, PhSPY, and showed that it can complement the spy-3 mutation in Arabidopsis. Overexpression of Spy in transgenic petunia plants affected various GA-regulated processes, including seed germination, shoot elongation, flower initiation, flower development and the expression of a GA- induced gene, GIP. In addition, anther development was inhibited in the transgenic plants following microsporogenesis. The N-terminus of Spy contains tetratricopeptide repeats (TPR). TPR motifs participate in protein-protein interactions, suggesting that Spy is part of a multiprotein complex. To test this hypothesis, we over-expressed the SPY's TPR region without the catalytic domain in transgenic petunia and generated a dominant- negative Spy mutant. The transgenic seeds were able to germinate on paclobutrazol, suggesting an enhanced GA signal. Overexpression of PhSPY in wild type Arabidopsis did not affect plant stature, morphology or flowering time. Consistent with Spy being an O-GlcNAc transferase (OGT), Spy expressed in insect cells was shown to O-GlcNAc modify itself. Consistent with O-GlcNAc modification playing a role in GA signaling, spy mutants had a reduction in the GlcNAc modification of several proteins. After treatment of the GA deficient, gal mutant, with GA3 the GlcNAc modification of proteins of the same size as those affected in spy mutants exhibited a reduction in GlcNAcylation. GA-induced GlcNAcase may be responsible for this de-GlcNAcylation because, treatment of gal with GA rapidly induced an increase in GlcNAcase activity. Several Arabidopsis proteins that interact with the TPR domain of Spy were identified using yeast two-hybrids screens. One of these proteins was GIGANTEA (GI). Consistent with GI and Spy functioning as a complex in the plant the spy-4 was epistatic to gi. These experiments also demonstrated that, in addition to its role in GA signaling, Spy functions in the light signaling pathways controlling hypocotyl elongation and photoperiodic induction of flowering. A second Arabidopsis OGT, SECRET AGENT (SCA), was discovered. Like SPY, SCA O-GlcNAc modifies itself. Although sca mutants do not exhibit dramatic phenotypes, spy/sca double mutants exhibit male and female gamete and embryo lethality, indicating that Spy and SCA have overlapping functions. These results suggest that O-GlcNAc modification is an essential modification in plants that has a role in multiple signaling pathways.
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Farazi, Mena, Michael Houghton, Margaret Murray e Gary Williamson. Systematic review of the inhibitory effect of extracts from edible parts of nuts on α-glucosidase activity. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, agosto 2022. http://dx.doi.org/10.37766/inplasy2022.8.0061.
Testo completoAbstract (sommario):
Review question / Objective: The aim of this review is to examine inhibitory effect of functional components in extracts from edible nuts on α-glucosidase activity. At the end of this review the following questions will be addressed by summarizing data of in-vitro studies: which nut extract has the strongest inhibitory effect? Which functional component (e.g. polyphenols) has the strongest inhibitory effect against α-glucosidase? Are there any differences between inhibition of α-glucosidase from different sources (e.g. yeast and mammalian)? Condition being studied: Any papers looking at inhibition of α-glucosidase activity (a carbohydrate digestive enzyme; includes sucrase, maltase and isomaltase activities) by extracts of edible parts of nut will be included in this review. Papers looking at other parts of nut plants and other enzymes will be excluded.