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1
Steffens, D., B. W. Hütsch, T. Eschholz, T. Lošák e S. Schubert. "Water logging may inhibit plant growth primarily by nutrient deficiency rather than nutrient toxicity". Plant, Soil and Environment 51, No. 12 (20 novembre 2011): 545–52. http://dx.doi.org/10.17221/3630-pse.
Testo completoAbstract (sommario):
The aim of our experiments was to investigate whether nutrient deficiency or toxicity is the cause for growth inhibition of wheat and barley in waterlogged soils. Experiments using two soils (top and subsoil) differing largely in various characteristics revealed a growth inhibition of wheat and barley in the case of subsoil due to water logging, without Fe or Mn toxicity. Water culture experiments with anaerobic (N<sub>2</sub>) and aerobic aeration confirmed that oxygen deficiency did not induce nutrient toxicity (Fe, Mn) but caused sub-optimum nutrient supply (N, P, K, Mn, Cu, Zn) of wheat and barley plants. In a split-root water culture experiment with barley, cultivating half of the root system in varying combinations of aerobic/anaerobic and with/without K supply, it was shown that sufficient K uptake occurred only when K and oxygen were applied in the same root compartment. We suggest that due to O<sub>2</sub> deficiency in the root medium, synthesis of ATP may be inhibited leading thus to a decrease in nutrient uptake. Nutrient deficiency rather than toxicity appears to be the major cause for the poor plant growth in waterlogged soils.
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Khan, Mohd Kamran, Anamika Pandey, Mehmet Hamurcu, Mateja Germ, Fatma Gokmen Yilmaz, Merve Ozbek, Zuhal Zeynep Avsaroglu, Ali Topal e Sait Gezgin. "Nutrient Homeostasis of Aegilops Accessions Differing in B Tolerance Level under Boron Toxic Growth Conditions". Biology 11, n. 8 (22 luglio 2022): 1094. http://dx.doi.org/10.3390/biology11081094.
Testo completoAbstract (sommario):
Boron (B) is a crucial microelement for several biological processes in plants; however, it becomes hazardous when present in excess in the soil. B toxicity adversely affects the wheat yield all around the world, particularly in the arid and semiarid regions. Aegilops, the nearest wild wheat relatives, could be an efficient source to develop B toxicity tolerance in modern cultivars. However, to potentially utilize these species, it is necessary to understand the underlying mechanisms that are involved in providing them tolerance. Other than hampering cellular and physiological activities, high B inhibits the uptake of nutrients in wheat plants that lead to nutrients deficiency causing a hindered growth. Thus, it is crucial to determine the effect of B toxicity on nutrient uptake and finally, to understand the role of nutrient homeostasis in developing the adaptive mechanism in tolerant species. Unfortunately, none of the studies to date has explored the effect of high B supply on the nutrient uptake in B toxicity tolerant wild wheat species. In this study, we explored the effect of 1 mM B (toxic B), and 10 mM B (very toxic B) B on the nutrient uptake in 19 Aegilops genotypes differing in B tolerance in contrast to Bolal 2973, the familiar B tolerant genotype. The obtained outcomes suggested a significant association between the B toxicity tolerance and the level of nutrient uptake in different genotypes. The B toxicity tolerant genotypes, Ab2 (TGB 026219, A. biuncialis genotype) and Ac4 (TGB 000107, A. columnaris genotype) were clustered together in the nutrient homeostasis-based heat map. Though B toxicity mostly had an inhibitory effect on the uptake of nutrients in root-shoot tissues, the tolerant genotypes revealed an increase in nutrient uptake under B toxicity in contrast with Control. The study directs towards future research where the role of external supply of few nutrients in enhancing the B toxicity tolerance of susceptible genotypes can be studied. Moreover, the genotype-dependent variation in the nutrient profile of the studied Aegilops genotypes under high B suggested that increasing number of Aegilops germplasm should be screened for B toxicity tolerance for their successful inclusion in the pre-breeding programs focusing on this issue.
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Pandey, Meena, Jiban Shrestha, Subash Subedi e Kabita Kumari Shah. "ROLE OF NUTRIENTS IN WHEAT: A REVIEW". Tropical Agrobiodiversity 1, n. 1 (18 giugno 2020): 18–23. http://dx.doi.org/10.26480/trab.01.2020.18.23.
Testo completoAbstract (sommario):
Wheat (Triticum aestivum L.) is an important cereal crop that provides ample nutritious calories for humans and animals. The nutrient plays a vital role in the production of wheat. In this review, previous works were evaluated to investigate the role of nutrients, nutrient deficiency and toxicity in wheat. Both macro and micronutrients are necessary for wheat plants. Every nutrient has its own character and is involved in different metabolic processes of plant life. Nutrient deficiency and toxicity conditions inhibit normal plant growth and exhibit characteristic symptoms. For optimal growth, development, and production, plants need all the necessary nutrients in balance. A balanced application of the primary nutrients (N, P, K), secondary nutrient (S) and some other micronutrients (Zn, B) are needed to enhance wheat production. The soil tests and the demand for crop nutrients should be assessed to identify the quantity of fertilizer recommended for the crop. This study would be a valuable means to wheat growers and researchers for sustainable and higher wheat production.
4
Mueller, Danica C., James S. Bonner, Robin L. Autenrieth, Kenneth Lee e Kenneth Doe. "The Toxicity of Oil-Contaminated Sediments During Bioremediation of a Wetland". International Oil Spill Conference Proceedings 1999, n. 1 (1 marzo 1999): 1049–52. http://dx.doi.org/10.7901/2169-3358-1999-1-1049.
Testo completoAbstract (sommario):
ABSTRACT Inorganic nutrients were applied to oiled wetland sediments during an experiment to assess the effect of enhanced bioremediation on petroleum degradation and toxicity reduction. For a period of 6 months after the controlled application of oil to experimental plots, oiled wetland sediment samples were tested for acute toxicity. The three treatments evaluated were an oiled control, inorganic nutrient addition, and inorganic nutrient addition plus an alternate electron acceptor. Sediment toxicity was assessed using Microtox® and amphipod bioassays. The Microtox® 100% Test detected significant sediment toxicity up to 29 days after oil and treatment application while the Solid-Phase Test detected significant sediment toxicity up to Day 15. The Microtox 100%® Test showed elevated toxicity on Day 8 for nutrient plus alternate electron acceptor plots and reduced toxicity on Day 15 for nutrient plots, relative to oiled controls. The observed decrease in sediment toxicity from the Microtox® assays correlated with petroleum losses. Oiled sediments were initially highly toxic to amphipods with average mortality rates ranging from 86 to 92%. Amphipod mortality decreased significantly 71 days after treatment to between 47 and 28%. However, a significant increase in mortality was observed at Day 140 in plots receiving nutrient amendments, possibly due to elevated ammonia levels.
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Dolling, PJ, WM Porter e AD Robson. "Effect of soil acidity on barley production in the south-west of Western Australia. 1. The interaction between lime and nutrient application". Australian Journal of Experimental Agriculture 31, n. 6 (1991): 803. http://dx.doi.org/10.1071/ea9910803.
Testo completoAbstract (sommario):
The effect of soil acidity on barley growth in Western Australia and the role of aluminium toxicity and nutrient deficiencies were examined at 9 sites using 5 application rates of lime and 3 levels of supply of nutrients. Nutrient plant analysis was also used to assess the mechanisms involved in any response to lime.Lime application increased barley yields at 3 sites, by 9-30%, by alleviating aluminium toxicity. Nutrient treatments did not interact with the lime response. The largest reduction in grain yield (>15%) that was due to aluminium toxicity occurred at the site which had the lowest pH (4.3 in 0.01 mol CaCl2/L) and the highest concentration of CaCl2-extractable aluminium (5 �g/g).
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Schier, George A., e Carolyn J. McQuattie. "Response of ectomycorrhizal and nonmycorrhizal pitch pine (Pinusrigida) seedlings to nutrient supply and aluminum: growth and mineral nutrition". Canadian Journal of Forest Research 26, n. 12 (1 dicembre 1996): 2145–52. http://dx.doi.org/10.1139/x26-243.
Testo completoAbstract (sommario):
Mycorrhizal colonization and nutrient supply may have important effects on aluminum toxicity in trees grown on acidic, nutrient-poor soils. The interacting effects of mycorrhizal inoculation, nutrient level, and Al treatment on growth and mineral nutrition of pitch pine (Pinusrigida Mill.) seedlings grown with and without the ectomycorrhizal fungus Pisolithustinctorius (Pers.) Coker & Couch were determined. The seedlings were grown for 66 days in sand irrigated with 0.1- or 0.2-strength nutrient solution (pH 3.8) containing 0, 10, or 20 mg/L Al (0, 0.37, or 0.74 mM). Across nutrient and Al levels total dry weight of ectomycorrhizal (ECM) seedlings was 75% greater than that of nonmycorrhizal (NM) seedlings. Doubling the nutrient level increased the dry weight of NM seedlings by 120%, versus 60% for ECM seedlings. Aluminum reduced root and shoot growth in NM seedlings, but had no effect on shoot growth and only a marginally significant effect on root growth of ECM seedlings. Shoot growth of NM seedlings was more sensitive to Al than root growth. Increased growth of NM seedlings by doubling the nutrient level was least at the highest Al level. Symptoms of Al toxicity in roots (dark, stunted tips) occurred at a lower Al level in NM than ECM seedlings. A strong relationship was not found between Al toxicity and concentrations of Mg and Ca in roots and needles. Enhancement of growth resulting from increased uptake of nutrients due to mycorrhizal inoculation (and) or an increased level of nutrients was the overriding factor affecting the response of pitch pine seedlings to Al.
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Choi, Jong‐Myung, Chun‐Ho Pak e Chiwon W. Lee. "Micro nutrient toxicity in French marigold". Journal of Plant Nutrition 19, n. 6 (giugno 1996): 901–16. http://dx.doi.org/10.1080/01904169609365169.
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Cockson, Paul, Hunter Landis, Turner Smith, Kristin Hicks e Brian E. Whipker. "Characterization of Nutrient Disorders of Cannabis sativa". Applied Sciences 9, n. 20 (18 ottobre 2019): 4432. http://dx.doi.org/10.3390/app9204432.
Testo completoAbstract (sommario):
Essential plant nutrients are needed at crop-specific concentrations to obtain optimum growth or yield. Plant tissue (foliar) analysis is the standard method for measuring those levels in crops. Symptoms of nutrient deficiency occur when those tissue concentrations fall to a level where growth or yield is negatively impacted and can serve as a visual diagnostic tool for growers and researchers. Both nutrient deficiency symptoms and their corresponding plant tissue concentrations have not been established for cannabis. To establish nutrient concentrations when deficiency or toxicity symptoms are expressed, Cannabis sativa ‘T1’ plants were grown in silica sand culture, and control plants received a complete modified Hoagland’s all-nitrate solution, whereas nutrient-deficient treatments were induced with a complete nutrient formula withholding a single nutrient. Toxicity treatments were induced by increasing the element tenfold higher than the complete nutrient formula. Plants were monitored daily and, once symptoms manifested, plant tissue analysis of all essential elements was performed by most recent mature leaf (MRML) tissue analysis, and descriptions and photographs of nutrient disorder symptomology were taken. Symptoms and progressions were tracked through initial, intermediate, and advanced stages. Information in this study can be used to diagnose nutrient disorders in Cannabis sativa.
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Munthe, Bonardo Vebry, Irwan Agusnu Putra e Dedi Kurniawan. "Defisiensi dan Toksisitas Hara Magnesium Tanaman Padi Gogo (Oryza Sativa L.) Pada Lapisan Tanah Subsoil". JINTAN : Jurnal Ilmiah Pertanian Nasional 2, n. 2 (28 luglio 2022): 129. http://dx.doi.org/10.30737/jintan.v2i2.2816.
Testo completoAbstract (sommario):
In increasing the production and quality of rice plants, it is essential to pay attention to proper nutrient management. One of the most important nutrients in increasing rice production and quality is magnesium, tested with deficiency and toxicity treatments in subsoil soils. This study used a factorial randomized block design with two factors where each treatment was repeated three times. First factor included Nutrient toxicity Mg, T0 = 0 (control), T1 = 2.2 g/polybag, T2 = 4.4 g/polybag, T3 = 8.8 g/polybag. Second factor included Mg nutrient deficiency D0 = 0 (control), D1 = 0.56 g/polybag, D2 = 0.28 g/polybag, and D3 = 0.14 g/polybag. The results showed that the deficiency treatment significantly affected plant height 5-6 weeks after fertilization and leaf chlorophyll 9 WSP. In contrast, the toxicity treatment significantly affected Total Chlorophyll 4 MSP and 1000 grain weight, where the D2 and T2 treatments showed the highest data. This study explained that the D2 and T2 treatments showed good plant responses. The red sigambiri variety was quite tolerant of magnesium deficiency and toxicity treatments.
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RUSSELLE, M. P., e R. L. McGRAW. "NUTRIENT STRESS IN BIRDSFOOT TREFOIL". Canadian Journal of Plant Science 66, n. 4 (1 ottobre 1986): 933–46. http://dx.doi.org/10.4141/cjps86-115.
Testo completoAbstract (sommario):
Birdsfoot trefoil (Lotus corniculatus L.) is often grown on poorly drained, low fertility, and low pH soils under marginal management. The objective of this research was to document several aspects of single nutrient stresses in birdsfoot trefoil. Plants were grown hydroponically in the glasshouse through two vegetative cycles and one reproductive growth cycle. Nutrient deficient treatments included P, K, Ca, Mg, S, B, Fe, Mn, Zn, Cu and Mo; toxicity treatments included B, Mn, Zn, Cu and Mo. Dry mass of shoots, shoot branching, and leaf area were typically lower in stressed plants than in plants grown in complete nutrient solution and specific leaf mass was generally larger in stressed plants. Nodule function and appearance were more severely affected by macronutrient than by micronutrient (except B) deficiencies. A deficiency or excess of a given nutrient often increased concentrations of other nutrients, but concentrations of some elements also decreased in response to a stress in another. In a few instances, concentrations of a nutrient differed from the complete treatment in an opposite manner in shoots than in roots. Seed yield and yield components were less frequently affected by nutrient stress than were herbage yields. Visual symptoms were generally similar to those of alfalfa (Medicago sativa) and the clovers (Trifolium spp.).Key words: Lotus corniculatus L., mineral nutrition, nutrient deficiency, nutrient toxicity, hydroponic solution culture, birdsfoot trefoil
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Bagale, Suman. "Nutrient Management for Soybean Crops". International Journal of Agronomy 2021 (6 settembre 2021): 1–10. http://dx.doi.org/10.1155/2021/3304634.
Testo completoAbstract (sommario):
Soybean is one of the most important pulse crops in the world which supplies most of the protein and oil requirements. The efficient production of soybean crops is a constraint, with several biotic factors, abiotic factors, and crop management practices. Nutrient management is one of the important aspects for achieving higher production of crops. Effective nutrient management helps to assure the required nutrients needed for the plant without causing a significant decrease in the yield of crops. In addition to this, managing the nutrient efficiently helps the crop to cope with several types of biotic and abiotic stress. For soybean crop, altogether fifteen nutrients are needed, which comprises six macronutrients, namely, nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur, which are required relatively in large amounts, and nine micronutrients which include iron, boron, zinc, cobalt, copper, manganese, molybdenum, nickel, and chlorine. These nutrients can be supplied to the plants through soil incorporation or foliar spray of commercially available fertilizers. Nutrient requirements for soybean crops vary in concentration, and deviations can cause nutrient deficiency or toxicity in soybean crops. Nutrient availability to soybean crops depends on the available nutrients in the soil solution, the form of available soil nutrients, mode of uptake of nutrients, its interaction with other soil nutrients, soil chemistry, and method of fertilizer application. This review article explores essential nutrients for sustainable soybean production in relation to the role and functions of nutrients, required concentration, and visual syndrome shown during deficiency, including findings from several researches. The review article is aimed to guide soybean farmers for effective nutrient management and academicians in reviewing the literature in soybean nutrient management.
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Baligar, V. C., N. K. Fageria e M. A. Elrashidi. "Toxicity and Nutrient Constraints on Root Growth". HortScience 33, n. 6 (ottobre 1998): 960–65. http://dx.doi.org/10.21273/hortsci.33.6.960.
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Roche, E., I. Maestre, F. Martín, E. Fuentes, J. Casero, J. A. Reig e B. Soria. "Nutrient toxicity in pancreatic β-cell dysfunction". Journal of Physiology and Biochemistry 56, n. 2 (giugno 2000): 119–28. http://dx.doi.org/10.1007/bf03179907.
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Mandal, Arindam, Saswati Biswas e Samares Pal. "Toxicity-mediated regime shifts in a contaminated nutrient–plankton system". Chaos: An Interdisciplinary Journal of Nonlinear Science 33, n. 2 (febbraio 2023): 023106. http://dx.doi.org/10.1063/5.0122206.
Testo completoAbstract (sommario):
In this article, we contemplate the dynamics of a three-tier system of nutrient, phytoplankton, and zooplankton with a gestation delay of discrete type and a distributed delay in nutrient recycling. Phytoplankton secretion-mediated alteration in the grazing pattern of zooplankton is encapsulated by a Monod–Haldane functional response. We carry out global sensitivity analysis for identifying the crucial model parameters having a significant impact on zooplankton density. The system potentially exhibits bistable configurations under identical ecological conditions by allowing different bifurcation scenarios, including multiple saddle-node and transcritical bifurcations with varying input rates of nutrients and inhibitory effects of phytoplankton against zooplankton. We observe that the gestation delay in zooplankton is responsible for the emergence of noxious bloom events. Interestingly, when the delay parameter crosses a threshold, the system experiences chaotic disorder, which prognosticates the onset of irregular bloom. Furthermore, by adding Gaussian white noise, we have extended the deterministic model to its stochastic counterpart. We found that white noise appears to regulate the survival and extinction of interacting populations. Comprehensive numerical simulations are consistent with mathematical results prognosticated by linear analysis.
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Sahrawat, K. L., C. K. Mulbah, S. Diatta, R. D. Delaune, W. H. Patrick, B. N. Singh e M. P. Jones. "The role of tolerant genotypes and plant nutrients in the management of iron toxicity in lowland rice". Journal of Agricultural Science 126, n. 2 (marzo 1996): 143–49. http://dx.doi.org/10.1017/s002185960007307x.
Testo completoAbstract (sommario):
SUMMARYIron toxicity is a nutrient disorder associated with high concentrations of iron in soil solutions. Deficiencies of other nutrients, such as P, K, Ca, Mg and Zn, have been implicated in its occurrence in rice plants. Field experiments were carried out in 1992 and 1993 in Ivory Coast to evaluate the iron toxicity tolerance of promising rice cultivars available in West Africa, and to provide additional information for selecting breeding materials. Two sites, differing in their potential to cause iron toxicity, were used. Glasshouse and field studies were also conducted to test the role of other nutrients in the occurrence of iron toxicity. The results showed that genetic tolerance to iron toxicity can significantly improve rice production in iron-toxic soils, with some cultivars producing yields in excess of 5 t/ha. The application of N, P, K and Zn in the field decreased the uptake of iron in rice tops, and this can be a significant factor in the iron-toxicity tolerance of the cultivars.
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Jahan, Badar, Faisal Rasheed, Zebus Sehar, Mehar Fatma, Noushina Iqbal, Asim Masood, Naser A. Anjum e Nafees A. Khan. "Coordinated Role of Nitric Oxide, Ethylene, Nitrogen, and Sulfur in Plant Salt Stress Tolerance". Stresses 1, n. 3 (8 settembre 2021): 181–99. http://dx.doi.org/10.3390/stresses1030014.
Testo completoAbstract (sommario):
Salt stress significantly contributes to major losses in agricultural productivity worldwide. The sustainable approach for salinity-accrued toxicity has been explored. The use of plant growth regulators/phytohormones, mineral nutrients and other signaling molecules is one of the major approaches for reversing salt-induced toxicity in plants. Application of the signaling molecules such as nitric oxide (NO) and ethylene (ETH) and major mineral nutrient such as nitrogen (N) and sulfur (S) play significant roles in combatting the major consequences of salt stress impacts in plants. However, the literature available on gaseous signaling molecules (NO/ETH) or/and mineral nutrients (N/S) stands alone, and major insights into the role of NO or/and ETH along with N and S in plant-tolerance to salt remained unclear. Thus, this review aimed to (a) briefly overview salt stress and highlight salt-induced toxicity, (b) appraise the literature reporting potential mechanisms underlying the role of gaseous signaling molecules and mineral nutrient in salt stress tolerance, and (c) discuss NO and ETH along with N and S in relation to salt stress tolerance. In addition, significant issues that have still to be investigated in this context have been mentioned.
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Bailey, Douglas A., e P. Allen Hammer. "Evaluation of Nutrient Deficiency and Micronutrient Toxicity Symptoms in Florists’ Hydrangea". Journal of the American Society for Horticultural Science 113, n. 3 (maggio 1988): 363–67. http://dx.doi.org/10.21273/jashs.113.3.363.
Testo completoAbstract (sommario):
Abstract Nutrient imbalances were investigated to a) document nutrient deficiency and micronutrient toxicity symptoms in florists’ hydrangea (Hydrangea macrophylla Thunb.) and b) examine the possible relationship of single-element deficiencies and toxicities with a foliar malformation prevelant on hydrangeas grown at >30°C. Plants subjected to N, P, K, Ca, Mg, S, B, Fe, and Zn deficiency and B and Mn toxicity treatments produced visual symptoms of the corresponding nutrient imbalance. Visual symptoms did not develop in +Fe, +Cu, +Zn, +Mo, −Mn, −Cu, and −Mo treatments. None of the symptoms induced were similar to the foliar malformations observed on hydrangeas grown at >30°. Hydrangea leaf malformation does not appear to be correlated with any single nutrient imbalance within hydrangea leaves. Results of the nutrient deficiency and toxicity experiments offer a diagnostic tool for interpretation of nutrient analysis of hydrangea.
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Pak, Chun-Ho, e Chiwon W. Lee. "MICRONUTRIENT TOXICITY IN PETUNIA HYBRIDA". HortScience 27, n. 6 (giugno 1992): 687e—687. http://dx.doi.org/10.21273/hortsci.27.6.687e.
Testo completoAbstract (sommario):
Foliar micronutrient toxicity symptoms of Petunia hybrida `Ultra Crimson Star' were induced by elevated levels (from 0.25 to 6 mM) of boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) in the nutrient solution. Foliar toxicity symptoms of most micronutrients (except Fe) were characterized by leaf yellowing, interveinal chlorosis, and marginal necrosis. Mo toxicity was most severe. Leaf abnormality was not induced by Fe in the concentration range tested. Visible foliar toxicity symptoms developed when nutrient solution contained 5.4, 32, 28, 24, and 16 mg· liter-1, respectively, of B, Cu, Mn, Mo and Zn. Biomass yield was reduced when the fertilizer solution contained (in mg· liter-1): 22 B, 64 Cu, 335 Fe, 28 Mn, 24 Mo, and 33 Zn.
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Kuswantoro, Heru. "Nutrient uptake of soybean genotypes under aluminum toxicity". Italian Journal of Agronomy 9, n. 3 (23 settembre 2014): 136. http://dx.doi.org/10.4081/ija.2014.600.
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PROIETTO, J. "Mechanisms of insulin resistance caused by nutrient toxicity". Hepatology Research 33, n. 2 (ottobre 2005): 87–91. http://dx.doi.org/10.1016/j.hepres.2005.09.010.
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Roper, Teryl R., e Armand R. Krueger. "Toxicity of Minor and Micronutrients in Cranberry". HortScience 33, n. 3 (giugno 1998): 468c—468. http://dx.doi.org/10.21273/hortsci.33.3.468c.
Testo completoAbstract (sommario):
Cranberry showed significant yield response to applied fertilizer. Some growers apply large quantities of some minor and micronutrients in an effort to increase yields. Tissue levels for nutrient sufficiency and excess have been determined in cranberry, but toxicity levels have not been determined. We exposed rooted cuttings of `Stevens' cranberry (Vaccinium macrocarpon Ait.) to high concentrations of individual nutrients in solution culture and then aeroponics. Shoot boron concentration rose rapidly, but not root concentration. At 300 ppm boron, leaf necrosis appeared and dry weight accumulation slowed. Copper and zinc accumulated in roots, but not in tops and thus will be difficult to diagnose. Shoot growth slowed with elevated root copper. Sulfur accumulated quickly in shoots and reduced growth when it exceeded 0.65%. These tissue levels are far higher than historical results from grower samples.
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Matar, A., W. L. Berry, C. L. Mackowiak, G. W. Stutte, R. M. Wheeler e J. C. Sager. "Tissue Nutrient Content Dynamics of Wheat and Potato Grown under Highly Productive Field and Hydroponic Conditions". HortScience 30, n. 4 (luglio 1995): 791A—791. http://dx.doi.org/10.21273/hortsci.30.4.791a.
Testo completoAbstract (sommario):
Tissue nutrient (element) content profiles were determined for wheat and potato plants grown hydroponically (NFT) in NASA's Biomass Production Chamber (20 m2) using a complete nutrient solution with electrical conductivity maintained at 0.12 S·m–1. Profiles were compared to patterns of nutrient accumulation during vegetative stages reported for highly productive wheat and potatoes grown in the field under a wide range of conditions. Among the essential elements, differences between the hydroponically and field-grown crops were observed only for Ca, Mg, and Mn in the recently mature leaves, and these differences were related to changes in growth phase and/or consistency of nutrient supply during plant growth. Nutrient profiles for both hydroponically and field-grown crops were also compared to deficiency and toxicity critical levels compiled by various workers. As expected for high-yielding crops, the profiles for both crops were well within the sufficiency ranges for all evaluated nutrients.
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Cole, David L., Savannah J. Kobza, Savannah R. Fahning, Samuel H. Stapley, Dicken K. A. Bonsrah, Rachel L. Buck e Bryan G. Hopkins. "Soybean Nutrition in a Novel Single-Nutrient Source Hydroponic Solution". Agronomy 11, n. 3 (11 marzo 2021): 523. http://dx.doi.org/10.3390/agronomy11030523.
Testo completoAbstract (sommario):
Hydroponic systems are efficient for studying plant nutrition. It is often desirable to adjust individual nutrients for unique species’ needs and/or to create multiple nutrient deficiencies within the same study. However, this is challenging to do with traditional solutions as nutrients are generally added as dual nutrient salts, such as when varying phosphorus (P) concentration also affects nitrogen concentration; potentially, the chemical form of the nutrient taken up when ammonium phosphate is the source for P. This can create unintended consequences with nutrients other than those intended for adjustment. A new hydroponic system has been created to allow for nutrient deficiencies using single-nutrient sources, including ammonium nitrate; phosphoric, sulfuric, hydrochloric, and boric acids; potassium, calcium, magnesium, zinc, and copper carbonates; manganese acetate; sodium molybdate; iron EDDHA; with HEDTA as an additional chelate. This nutrient solution was compared to a traditional “Hoagland” hydroponic solution to grow soybean (Glycine max (L.) Merr). Additional treatments included alteration of pH in the new solution as well as evaluating varying levels of calcium, magnesium, and manganese. This new solution proved effective, as soybean was grown to maturity and performed as well as the traditional Hoagland solution. Adjusting pH downward with hydrochloric acid resulted in healthy plants, but solution pH was not adequately buffered. Adjusting pH with acetic acid resulted in toxicity. Further work is required to provide better pH buffering and approximately align tissue nutrient concentrations with field-grown soybean.
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Romero Rosales, Kimberly, Gurpreet Singh, Kevin Wu, Jie Chen, Matthew R. Janes, Michael B. Lilly, Eigen R. Peralta et al. "Sphingolipid-based drugs selectively kill cancer cells by down-regulating nutrient transporter proteins". Biochemical Journal 439, n. 2 (28 settembre 2011): 299–311. http://dx.doi.org/10.1042/bj20110853.
Testo completoAbstract (sommario):
Cancer cells are hypersensitive to nutrient limitation because oncogenes constitutively drive glycolytic and TCA (tricarboxylic acid) cycle intermediates into biosynthetic pathways. As the anaplerotic reactions that replace these intermediates are fueled by imported nutrients, the cancer cell's ability to generate ATP becomes compromised under nutrient-limiting conditions. In addition, most cancer cells have defects in autophagy, the catabolic process that provides nutrients from internal sources when external nutrients are unavailable. Normal cells, in contrast, can adapt to the nutrient stress that kills cancer cells by becoming quiescent and catabolic. In the present study we show that FTY720, a water-soluble sphingolipid drug that is effective in many animal cancer models, selectively starves cancer cells to death by down-regulating nutrient transporter proteins. Consistent with a bioenergetic mechanism of action, FTY720 induced homoeostatic autophagy. Cells were protected from FTY720 by cell-permeant nutrients or by reducing nutrient demand, but blocking apoptosis was ineffective. Importantly, AAL-149, a FTY720 analogue that lacks FTY720's dose-limiting toxicity, also triggered transporter loss and killed patient-derived leukaemias while sparing cells isolated from normal donors. As they target the metabolic profile of cancer cells rather than specific oncogenic mutations, FTY720 analogues such as AAL-149 should be effective against many different tumour types, particularly in combination with drugs that inhibit autophagy.
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Elemike, Elias, Ifeyinwa Uzoh, Damian Onwudiwe e Olubukola Babalola. "The Role of Nanotechnology in the Fortification of Plant Nutrients and Improvement of Crop Production". Applied Sciences 9, n. 3 (1 febbraio 2019): 499. http://dx.doi.org/10.3390/app9030499.
Testo completoAbstract (sommario):
Nutrient deficiency in food crops is seriously affecting human health, especially those in the rural areas, and nanotechnology may become the most sustainable approach to alleviating this challenge. There are several ways of fortifying the nutrients in food such as dietary diversification, use of drugs and industrial fortification. However, the affordability and sustainability of these methods have not been completely achieved. Plants absorb nutrients from fertilizers, but most conventional fertilizers have low nutrient use and uptake efficiency. Nanofertilizers are, therefore, engineered to be target oriented and not easily lost. This review surveys the effects of the addition of macro- and nanonutrients to soil, the interaction, and the absorption capability of the plants, the environmental effect and food content of the nutrients. Most reports were obtained from recent works, and they show that plants nutrients could be enriched by applying nanoparticulate nutrients, which are easily absorbed by the plant. Although there are some toxicity issues associated with the use of nanoparticles in crop, biologically synthesized nanoparticles may be preferred for agricultural purposes. This would circumvent the concerns associated with toxicity, in addition to being pollution free. This report, therefore, offers more understanding on the application of nanotechnology in biofortification of plant nutrients and the future possibilities offered by this practice. It also highlights some of the ills associated with the introduction of nanomaterials into the soil for crop’s improvement.
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Q. Brearley, Francis. "Root Mass and Elemental Concentrations in an Irish Oak Woodland". Science & Technology Journal 8, n. 2 (1 luglio 2020): 5–7. http://dx.doi.org/10.22232/stj.2020.08.02.01.
Testo completoAbstract (sommario):
Fine roots (< 2 mm diameter) are key for nutrient and carbon cycling in forests but less well studied for oak than other European trees. To better understand controls on root mass and nutrient concentrations in oak stands, a study was conducted at Glendalough in Ireland. Roots were removed from soils and measured for biomass, length and nutrient concentrations along with soil nutrients. Fine root mass was 360 gm-2 and comparable to other oak stands. Whilst root N concentrations were high, P concentrations were low and N, P, K, Mg, but not C or Ca were at greater concentrations in fine roots compared to coarse (2-5 mm) roots. The root Ca:Al ratio suggested Al toxicity although this was less marked in organic-rich soils. Neither root mass nor root nutrient concentrations showed particularly strong correlations with soil nutrients or pH. Whilst this data agrees well with other similar studies, improved analysis by separating live and dead roots will further advance our understanding of controls on forest fine root dynamics.
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Barnes, Jared, Brian Whipker, Ingram McCall e Jonathan Frantz. "Nutrient Disorders of ‘Evolution’ Mealy-cup Sage". HortTechnology 22, n. 4 (agosto 2012): 502–8. http://dx.doi.org/10.21273/horttech.22.4.502.
Testo completoAbstract (sommario):
To produce floriculture crops like mealy-cup sage (Salvia farinacea), growers must be equipped with cultural information including the ability to recognize and characterize nutrient disorders. ‘Evolution’ mealy-cup sage plants were grown in silica-sand culture to induce, describe, and photograph symptoms of nutritional disorders. Plants received a complete modified Hoagland's all-nitrate solution of (macronutrient concentrations in millimoles) 15 nitrate-nitrogen (N), 1.0 phosphorus (P), 6.0 potassium (K), 5.0 calcium (Ca), 2.0 magnesium (Mg), and 2.0 sulfur (S) plus (micronutrient concentrations in micromoles) 72 iron (Fe), 18 manganese (Mn), 3 copper (Cu), 3 zinc (Zn), 45 boron (B), and 0.1 molybdenum (Mo). Nutrient-deficient treatments were induced with a complete nutrient formula minus one of the nutrients. The B-toxicity treatment was induced by increasing the element 10-fold higher than the complete nutrient formula. Reagent-grade chemicals and deionized (DI) water of 18 million ohms per centimeter purity were used to formulate treatment solutions. We monitored plants daily to document and photograph sequential series of symptoms as they developed. Typical symptomology of nutrient disorders and corresponding tissue concentrations were determined. Out of 13 treatments, 12 exhibited symptomology; Mo was asymptomatic. Symptoms of N, P, S, Ca, and K deficiencies and B toxicity manifested early; therefore, these disorders may be more likely problems encountered by growers. Unique symptoms were observed on plants grown under N-, Cu-, and Zn-deficient conditions. Necrosis was a common symptom observed, but use of other diagnostic criteria about location on the plant and progression of the disorder can aid growers in diagnosing nutrient disorders of mealy-cup sage.
28
Schier, George A., e Carolyn J. Mcquattie. "Effect of aluminum on the growth, anatomy, and nutrient content of ectomycorrhizal and nonmycorrhizal eastern white pine seedlings". Canadian Journal of Forest Research 25, n. 8 (1 agosto 1995): 1252–62. http://dx.doi.org/10.1139/x95-138.
Testo completoAbstract (sommario):
Effect of aluminum (Al) on the growth, anatomy, and nutrient content of eastern white pine (Pinusstrobus L.) was determined by growing newly germinated seedlings for 12 weeks in sand irrigated with nutrient solution (pH 3.8) containing 0, 12.5, 25, 50, 75, or 100 mg/L of Al. To determine the influence of mycorrhizal infection on Al toxicity, half of the seedlings were inoculated with the ectomycorrhizal fungus Pisolithustinctorius (Pers.) Coker & Couch. Across Al concentrations, shoot growth (height, needle length, biomass) but not root growth (lateral root length, biomass) was significantly greater in ectomycorrhizal (ECT) than nonmycorrhizal (NM) seedlings. Aluminum significantly decreased shoot and root growth in ECT and NM seedlings but had less effect on growth in ECT seedlings. Foliar symptoms of Al toxicity (chlorosis, tip necrosis) were more pronounced in NM than in ECT seedlings. Cellular and ultrastructural injury to needles and root meristematic tissues was observed at lower concentrations of Al in NM seedlings than in ECT seedlings. Amelioration of Al toxicity by mycorrhizal colonization appeared to result from enhanced uptake of nutrients, especially P, rather than to reduced uptake of Al.
29
OLALEYE, Adesola Olutayo, Ayoade Olayiwola OGUNKUNLE, Baij Nath SINGH, Festus Olugbenga ODELEYE, Oyeyemi Adigun DADA e Bolarinwa Ayoola SENJOBI. "Elemental Composition of Two Rice Cultivars under Potentially Toxic an Aquept and Aquent". Notulae Scientia Biologicae 1, n. 1 (7 dicembre 2009): 46–49. http://dx.doi.org/10.15835/nsb113470.
Testo completoAbstract (sommario):
Iron toxicity is a major nutrient disorder affecting rice production of wetland rice in the irrigated and rainfed ecosystem in West Africa sub-region. Little attention has been paid to evaluating nutrient contents of rice cultivars grown on such soils and their relationship to the iron toxicity scores, grain yield and dry matter yields. A pot experiment was conducted on two potentially Fe-toxic soils (Aeric Fluvaquent and Aeric Tropaquept). The experiment was a 2 x 2 x 4 factorial experiment with three replicates in arranged in a randomized fashion. The factors were two soil types, two rice cultivars (ITA 212) and tolerant (Suakoko 8) and four Fe 2+ levels (control, 1000, 3000 and 4000 mg L-1). The result showed that for both susceptible cultivar (ITA 212) and the relatively tolerant (Suakoko 8) cultivar, little or no differences were observed in their elemental composition with regards to micro and macro-nutrients. For the susceptible cultivar, results showed that none of the tissue nutrients significantly relates to iron toxicity scores (ITS), grain yield and dry matter yield on both soil types. However, for the tolerant cultivar, ITS was observed to be significantly related to tissue K and P contents on the two soil types respectively. Tissue Ca and Mg were observed to be significantly related to the dry matter yield (DMY) on Aeric Tropquept. It could be concluded that for these rice cultivars grown on two potentially Fe-toxic soils, different tissue nutrients may trigger the manifestation of bronzing or yellowing symptoms of rice cultivars.
30
Iswahyudi, Bagus, e Bakri Bakri. "Pemetaan Status Unsur Hara Fosfor Perkebunan Kelapa Sawit Rakyat di Kelurahan Babat Sumatera Selatan". Jurnal Lahan Suboptimal : Journal of Suboptimal Lands 8, n. 1 (17 gennaio 2019): 77–85. http://dx.doi.org/10.33230/jlso.8.1.2019.408.
Testo completoAbstract (sommario):
Iswahyudi et al, 2019. Oil Palm Plantation’s Phosporous Mineral Mapping on Babat District South Sumatera. JLSO 8(1):77-85. Soil nutrient status mapping was not initiated which lead to inefficiency in fertilization. Fertilizition without nutrient analysis could lead to nutrient deficiency or toxicity of nutrint. The Purpose of this research was to identify, map the nutrient status and fertilization recomendation of phosporous nutrient status in public oil palm plantation at Babat Village Babat Toman Districts Musi Banyuasin District South Sumatera Province. This research used a detailed survey methode with grid system for 16 sample which represent 16 ha and 60 cm depth of soil drilling. Phosporous nutrient status at research location ranged from 4,81 ppm to 21,86 ppm. 7 ha contained 8-20 ppm available phosphorous ot classified into medium, 6 ha contained < 8 ppm available phosphorous or classified into low and 3 h contained >20 ppm available phosporous or classified into high. Soil reaction (pH) of the research field was 5,0 and 5,5 which classify the soil into acid soil. Fertilization implemented to increase the nutrient status until medium (15 ppm) which resulted in SP-36 doses was 346,22 kg/ha for low nutrient status and 139,33 kg/ha for medium nutrient status.
31
Lee, Kyu-Min, Chiwon W. Lee e Murray E. Duysen. "Induced Iron Toxicity in Chinese Cabbage and Leaf Lettuce". HortScience 30, n. 4 (luglio 1995): 864C—864. http://dx.doi.org/10.21273/hortsci.30.4.864c.
Testo completoAbstract (sommario):
The influences of elevated nutrient solution Fe++ concentrations on tissue iron contents and toxicity symptom development in Chinese cabbage and leaf lettuce were investigated. Seedling plants established in peat-lite mix in 15-cm plastic pots were fertilized with nutrient solutions containing 0 to 10 mM Fe++ for 6 weeks. Both Chinese cabbage and leaf lettuce produced dark leaf spots on plants grown with 5 mM or higher Fe++ concentrations. Biomass yields were reduced when leaf tissue iron contents in Chinese cabbage and leaf lettuce, respectively, were 551 mg·kg–1 and 379 mg·kg–1 or higher on a dry matter basis. In both species, tissue iron contents increased as the nutrient Fe++ concentration increased. Tissue iron contents in both species may be greatly enhanced to a certain level without causing plant toxicity by micronutrient fertilization.
32
Yang, Tao-Yu, Li-Ya Cai, Yi-Ping Qi, Lin-Tong Yang, Ning-Wei Lai e Li-Song Chen. "Increasing Nutrient Solution pH Alleviated Aluminum-Induced Inhibition of Growth and Impairment of Photosynthetic Electron Transport Chain in Citrus sinensis Seedlings". BioMed Research International 2019 (27 agosto 2019): 1–17. http://dx.doi.org/10.1155/2019/9058715.
Testo completoAbstract (sommario):
Although the physiological and molecular responses of Citrus to Al-toxicity or low pH have been examined in some details, little information is available on Citrus responses to pH and aluminum (Al) interactions. Citrus sinensis seedlings were irrigated for 18 weeks with nutrient solution at a concentration of 0 or 1 mM AlCl3•6H2O and a pH of 2.5, 3.0, 3.5, or 4.0. Thereafter, biomass, root, stem, and leaf concentrations of Al and nutrients, leaf gas exchange, chlorophyll a fluorescence (OJIP) transients, and related parameters were investigated to understand the physiological mechanisms underlying the elevated pH-induced alleviation of Citrus toxicity. Increasing the nutrient solution pH from 2.5 to 4.0 alleviated the Al-toxic effects on biomass, photosynthesis, OJIP transients and related parameters, and element concentrations, uptake, and distributions. In addition, low pH effects on the above physiological parameters were intensified by Al-toxicity. Evidently, a synergism existed between low pH and Al-toxicity. Increasing pH decreased Al uptake per root dry weight and its concentration in roots, stems, and leaves and increased nitrogen, phosphorus, calcium, magnesium, sulfur, and boron uptake per plant and their concentrations in roots, stems, and leaves. This might be responsible for the elevated pH-induced alleviation of growth inhibition and the impairment of the whole photosynthetic electron transport chain, thus preventing the decrease of CO2 assimilation.
33
Jie Yang, Ming, Xiao E Yang e Volker Römheld. "GROWTH AND NUTRIENT COMPOSITION OFELSHOLTZIA SPLENDENSNAKAI UNDER COPPER TOXICITY". Journal of Plant Nutrition 25, n. 7 (11 luglio 2002): 1359–75. http://dx.doi.org/10.1081/pln-120005395.
Testo completo
34
Turhadi, Miftahuddin, Hamim e Munif Ghulamahdi. "The Effectiveness of Nutrient Culture Solutions with Agar Addition as An Evaluation Media of Rice Under Iron Toxicity Conditions". BIOEDUSCIENCE 5, n. 1 (30 aprile 2021): 24–29. http://dx.doi.org/10.22236/j.bes/516395.
Testo completoAbstract (sommario):
Background: Evaluation of the tolerance level of rice to iron (Fe) toxicity stress can be done using a hydroponic system in a nutrient culture solution under a controlled condition. This study aimed to obtain a nutrient culture solution that effective as a medium for evaluating the response of rice under Fe toxicity stress condition. Methods: This experiment was carried out by comparing the effectiveness of three kinds of nutrient culture media, namely Yoshida’s Half-Strength solution (HSY), Yoshida’s Half-Strength + 0.2% agar solution (HSYA), and Yoshida’s Full-Strength + 0.2% agar solution (FSYA) using two rice genotypes, Inpara 5 (sensitive to Fe toxicity) and Mahsuri (tolerant to Fe toxicity). Leaf bronzing level, plant dry weight, and pH of nutrient culture media were observed in this experiment. Results: The results showed that the stress response as represented by the bronzing score in Inpara 5 leaves was known to be higher than that of Mahsuri in the three nutrient culture media. The decrease of root and shoot dry weight in Inpara 5 was higher than that of Mahsuri. In addition, the decrease in the pH of nutrient culture solution media without an agar addition (HSY) occurred faster than the media with the agar addition (HSYA and FSYA). Conclusion: The HSYA and FSYA media exhibited a similar pattern of pH declining but causing significant differences in growth responses between Inpara 5 and Mashuri indicating the HSYA medium is considered more efficient compared to the FSYA medium because it only requires a smaller amount of agar.
35
Kerr, Skyler M., Elmer W. Gray e Darold Batzer. "Evaluation of Larval Medium in the Controlled Current Toxicity Test". Journal of the American Mosquito Control Association 35, n. 4 (1 dicembre 2019): 295–98. http://dx.doi.org/10.2987/19-6837.1.
Testo completoAbstract (sommario):
ABSTRACT The Controlled Current Toxicity Test (CCTT) is a protocol used by the University of Georgia Black Fly Rearing and Bioassay Laboratory to evaluate the efficacy of larvicides based on Bacillus thuringiensis subsp. israelensis (Bti) against Simulium vittatum larvae. A standard CCTT provides a larval medium with suspended organic nutrients, a sustained current, and a clean surface for black fly larval attachment in each exposure vessel. In an effort to streamline the CCTT and eliminate a potential source of variability, 3 types of larval medium were evaluated: deionized water, distilled water, and moderately hard water, which were compared to the currently used protocol. A statistical significance in mean lethal concentration (LC50) rates was observed between the CCTT (deionized water with suspended organic nutrients) medium and the other 3 experimental media. The presence of suspended organic nutrients in the CCTT significantly improved the efficacy of the Bti-based larvicide. The interaction of the suspended organic nutrient particles and the Bti-based particles in the larvicide appears to produce a mixture that is more efficiently captured and ingested by the black fly larvae than the larvicide formulation particles alone.
36
Almeida-Cortez, J. S., B. Shipley e J. T. Arnason. "Growth and chemical defense in relation to resource availability: tradeoffs or common responses to environmental stress?" Brazilian Journal of Biology 64, n. 2 (maggio 2004): 187–94. http://dx.doi.org/10.1590/s1519-69842004000200002.
Testo completoAbstract (sommario):
One aspect of plant defense is the production of constitutive secondary compounds that confer toxicity on herbivores and pathogens. The purpose of this study was to compare patterns of plant tissue toxicity across gradients of irradiance and nutrient content. We measured the potential toxicity (1/LC50) of extracts of six species of herbaceous Asteraceae grown under controlled conditions of temperature (25ºC), humidity (80%), photoperiod (16 h/day), in a range of concentrations of a modified Hoagland hydroponic solution (full-strength, 1/5 dilute, 1/10 dilute, and 1/50 dilute) and under two different light intensities (250 and 125 mumol/m²/s). The plants grew from seed for 42 days post-germination, and randomly chosen plants were harvested each 7 days. We did a general measure of potential phytochemical toxicity using an alcohol extraction of secondary compounds followed by brine shrimp (Artemia sp.) bioassay. Contrary to the carbon/nutrient balance hypothesis, tissue toxicity generally increased with decreasing irradiance and nutrient levels, so that plants whose growth was most restricted had tissues that were most toxic, although there were species-specific differences in this trend.
37
Cockson, Paul, Josh B. Henry, Ingram McCall e Brian E. Whipker. "Nutrient Disorders of ‘Orchestra Pink’ Gloxinia". HortTechnology 27, n. 6 (dicembre 2017): 789–93. http://dx.doi.org/10.21273/horttech03833-17.
Testo completoAbstract (sommario):
To produce popular floriculture crops, such as gloxinia (Sinningia speciosa), growers must be equipped with cultural information including the ability to recognize and characterize disorders. Diagnostic criteria for nutrient disorders of gloxinia are absent from current literature. Therefore, gloxinia plants were grown in silica-sand culture to induce, characterize, and photograph symptoms of nutritional disorders. Control plants received a complete modified Hoagland’s all-nitrate solution, whereas nutrient-deficient treatments were induced with a complete nutrient formula minus a single nutrient. Boron toxicity was induced by increasing the element 10-fold higher than the complete nutrient formula. We monitored plants continuously to document and photograph sequential series of symptoms as they developed. Typical symptomology of nutrient disorders and critical tissue concentrations are presented. Of 13 treatments, 10 exhibited symptomology; copper, molybdenum, and zinc remained asymptomatic. Symptoms of nitrogen, phosphorus, potassium, magnesium, and sulfur deficiencies, plus boron toxicity manifested early; therefore, these disorders may be more likely problems encountered by growers. Unique symptoms were observed on plants grown in nitrogen, potassium, sulfur, and iron deficient and boron toxic conditions.
38
Kitajima, Toshihiko, e Yasunori Chiba. "Selenomethionine metabolism and its toxicity in yeast". BioMolecular Concepts 4, n. 6 (1 dicembre 2013): 611–16. http://dx.doi.org/10.1515/bmc-2013-0033.
Testo completoAbstract (sommario):
AbstractThe importance of selenium for organisms can be explained by its existence as selenocysteine in the catalytic centers of glutathione peroxidase and thioredoxin reductase. Another selenoamino acid, selenomethionine, is the major form of selenium in foods, and organisms that require selenium as a nutrient directly metabolize selenomethionine to a reactive form of selenium or store it in general proteins. Selenium is recognized as an essential nutrient for human and animal health; however, its excessive uptake harms mammals and the cytotoxic mechanism of selenium remains unclear. Recent progress in the development of selenium-enriched yeast and selenomethionine-resistant mutant to produce selenomethionine-containing proteins for X-ray crystallography has provided new insights into the molecular mechanism of selenomethionine toxicity. In this review, we describe the metabolism of seleno-compounds in yeast and discuss the cytotoxicity caused by selenomethionine against yeast from a metabolic viewpoint.
39
Freitas, Lucas B. de, Dirceu M. Fernandes, Suelen C. M. Maia, Arianne Moniz, Beatriz G. Mazziero e Fábio Steiner. "Sources and doses of aluminum in experiments with rice in nutrient solution". Revista Brasileira de Engenharia Agrícola e Ambiental 23, n. 7 (luglio 2019): 511–17. http://dx.doi.org/10.1590/1807-1929/agriambi.v23n7p511-517.
Testo completoAbstract (sommario):
ABSTRACT The aluminum source to produce toxicity in upland rice in nutrient solution experiments is not yet well established, althought the aluminum potassium sulfate has been utilized source to produce aluminum toxicity. However, in recent studies have used aluminum chloride. The aim of this study was to evaluate the capacity of aluminum sources and doses to produce toxicity in upland rice plants grown in nutrient solution. The experiment was arranged in a block randomized design, in a 2 x 5 factorial scheme and four repetitions. The treatments were two aluminum sources (aluminum potassium sulfate - AlK(SO4)2.12H2O and aluminum chloride - AlCl3.6H2O) and five aluminum doses in nutrient solution (0, 370, 740, 1100 and 1480 μmol L-1). The experiment was conducted in a greenhouse in Botucatu city, São Paulo state, Brazil, starting in April 2012, and was carried out for 56 days from transplanting of the seedlings. Using aluminum chloride, the rice plants show lower production of root and total dry weight, area and root volume, medium and thick root length, potassium and sulfur contents and accumulations. Using aluminum potassium sulfate, there are lower aluminum activity and availability, besides the formation of large amount of aluminum compounds non-toxic to the plants (aluminum sulfate) in the nutrient solution. The aluminum doses between 1100 to 1480 µmol L-1, corresponding to aluminum activity of 336.8 to 429.0 µmol L-1 of aluminum chloride as source, are more effective to produce aluminum toxicity in upland rice plants grown in nutrient solution.
40
Barr, Susan I. "Introduction to Dietary Reference Intakes". Applied Physiology, Nutrition, and Metabolism 31, n. 1 (1 febbraio 2006): 61–65. http://dx.doi.org/10.1139/h05-019.
Testo completoAbstract (sommario):
Dietary Reference Intakes (DRIs) are nutrient reference standards used for planning and assessing the diets of apparently healthy Canadians and Americans. The development of DRIs reflects a joint initiative by the United States and Canada to update, expand on, and replace the former Recommended Nutrient Intakes for Canadians and Recommended Dietary Allowances for Americans. DRIs include the Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI), and Tolerable Upper Intake Level (UL). The EAR is the average daily intake level that meets the requirement of 50% of healthy individuals in a life stage and gender group, whereas the RDA is set at a level that will meet the requirements of almost all (97%-98%) individuals in that life stage and gender group. An AI is a recommended intake level that is thought to meet the needs of almost all healthy individuals, and is set when there are insufficient data to establish an EAR (and therefore an RDA). The UL represents a threshold above which adverse effects of excessive intake may increase. In addition to these DRIs, macro nutrients have an Acceptable Macro nutrient Distribution Range (AMDR) and, for energy, an Estimated Energy Requirement (EER) is described.Key words: nutrient reference standards, nutrient requirements, nutrient toxicity.
41
Jibril, Sani Ahmad, Siti Aishah Hassan, Che Fauziah Ishak e Puteri Edaroyati Megat Wahab. "Cadmium Toxicity Affects Phytochemicals and Nutrient Elements Composition of Lettuce (Lactuca sativa L.)". Advances in Agriculture 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/1236830.
Testo completoAbstract (sommario):
Lettuce varieties Bombilasta BBL and Italian 167 were treated with different concentrations of cadmium (0, 3, 6, 9, and 12 mg/L) in a nutrient film technique (NFT) system to study its toxicity on phytochemicals and nutrient elements. Antioxidants analysis which employed DPPH and FRAP, flavonoids, phenolic, vitamin C, malondialdehyde (MDA), and proline indicated significant effects of Cd treatment on the varieties tested. Different concentration levels of Cd lead to positive interactions in FRAP, phenolic, and MDA but no significant effect in flavonoids, vitamin C, and proline. Contents of macro- and microelements in the varieties were significantly affected with increase in the toxicity levels of Cd in all nutrient elements tested with interactions exhibited for iron, manganese, and zinc.
42
Bercz, J. P. "Endocrine Toxicity of Drinking Water Disinfectants. I. In Vivo Dehalogenation and Clearance of Iodinated Nutrients". Journal of the American College of Toxicology 10, n. 5 (settembre 1991): 525–32. http://dx.doi.org/10.3109/10915819109078649.
Testo completoAbstract (sommario):
Ingestion of aqueous chlorine-based disinfectants has been shown earlier to cause decreased serum thyroxine levels and increased 131-I thyroid uptake in nonhuman primates. Disinfectants also were shown to immobilize iodine on gastric mucosa and cause covalent binding of dietary iodide to gastrointestinal contents in laboratory rodents. It has been demonstrated that nutrients in the presence of chlorine oxides, under conditions simulating the alimentary tract, effectively organify I- in vitro. A logical consequence of these is that traces of iodinated organics are absorbed after ingestion of drinking water disinfectants. Since over 100 million consumers receive a daily dose of about 0.4 mM of free chlorine, the pharmacotoxicology of such modified nutrient molecules is of public health interest. Therefore, we examined the in vivo deiodination of randomly in vitro iodinated organic mixtures prepared from different nutrients. Using adult female rats, we determined the 24-hour thyroid uptake of 125-I liberated from nutrients administered by gavage, relative to simultaneously ip-injected I131-. Also, 24-hour fecal and urinary clearances of the iodinated organics as well as tissue distributions were determined. The results showed that although various iodinated nutrient classes widely differed in their in vivo fate, most were dehalogenated effectively. Thus, their iodine content was returned as inorganic I- for thyroid uptake. It was also shown that tissue (blood, liver, intestinal, adipose, and muscle) distribution of the two isotopes did not differ significantly, suggesting that at 24 hours, the originally organic iodine existed in the tissues as inorganic I-. It is likely that oral exposure to chlorine-based disinfectants did not disturb the bioavailability of I-, and any thyroid effects caused were due to mechanisms other than I- deficiency.
43
., S. Venkatesan, K. V. Hemalatha . e S. Jayaganesh . "Zinc Toxicity and its Influence on Nutrient Uptake in Tea". American Journal of Plant Physiology 1, n. 2 (15 febbraio 2006): 185–92. http://dx.doi.org/10.3923/ajpp.2006.185.192.
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44
Lin, Kuo‐Ching, Chwen‐I Lin e Chung‐Yuan Chen. "The effect of limiting nutrient on metal toxicity toselenastrum capricornutum". Toxicological & Environmental Chemistry 56, n. 1-4 (agosto 1996): 47–61. http://dx.doi.org/10.1080/02772249609358349.
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45
MIAO, A., e W. WANG. "Cadmium toxicity to two marine phytoplankton under different nutrient conditions". Aquatic Toxicology 78, n. 2 (15 giugno 2006): 114–26. http://dx.doi.org/10.1016/j.aquatox.2006.02.008.
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46
Mortley, Desmond G. "MANGANESE TOXICITY OR TOLERANCE IN SWEETPOTATO". HortScience 27, n. 6 (giugno 1992): 665e—665. http://dx.doi.org/10.21273/hortsci.27.6.665e.
Testo completoAbstract (sommario):
Greenhouse studies were conducted to evaluate 5 levels of Mn (0.00025 to 0.1 g.L-1) on Mn toxicity or tolerance of sweetpotato [Ipomoea batatas (L.) Lam] grown in a modified half Hoagland's solution. The presence of oxidized Mn on the roots and leaves was demonstrated by the blue staining test with benzidene and the solubility and bleaching of oxidized Mn in the oxalic-sulfuric acid solution. Both storage root and foliage fresh and dry weights were highest at Mn concn of 0.00025 g.L-1 in the nutrient solution, while fibrous root dry weight was highest with 0.01 g.L-1 Mn in the solution. More Mn accumulated in foliage than in fibrous roots for all levels of Mn evaluated. N, P, and K concn in foliage was highest at a Mn concn of 0.1 g.L-1 Mn in the solution. Foliage dry weight was preserved up to a high Mn level of about 2700 ug. g-1 Mn in tissues, while taht for storage roots was preserved up to a high Mn level of about 1000 ug. g-1 in the tissues. Deposition of oxidized Mn was observed on fibrous roots particularly at the highest Mn levels in the nutrient solution.
47
Reddy Anthay, Swetha, Arun Chokkalingam, Komathi B. Jeyashanker e Bharathiraja Natarajan. "An analysis on micronutrient deficiency in plant leaf and soil using digital image processing". Indonesian Journal of Electrical Engineering and Computer Science 26, n. 1 (1 aprile 2022): 568. http://dx.doi.org/10.11591/ijeecs.v26.i1.pp568-575.
Testo completoAbstract (sommario):
The plant <span>requires thirteen different nutrients. The two main types of nutrients are micronutrients and macronutrients. Diseases develop due to deficiency of vital nutrients, resulting in colored spots on the leaves. Plant development is affected by toxicity or lack of one or more of these nutrients, resulting in plant death. As a result, a continuous monitoring system is necessary to know the nutritional status of the plants to enhance production efficiency and output. Optical image recognition-based medical technology can identify indicators of inaccuracy faster than the human eye. Consequently, farmers are prepared to take prompt and effective remedial action. This article investigates the nutrient deficits in plants using image processing techniques.</span>
48
Lee, Kenneth, Kenneth G. Doe, Lucila E. J. Lee, Makram T. Suidan e Albert D. Venosa. "Remediation of an Oil-Contaminated Experimental Freshwater Wetland: II. Habitat Recovery and Toxicity Reduction". International Oil Spill Conference Proceedings 2001, n. 1 (1 marzo 2001): 323–28. http://dx.doi.org/10.7901/2169-3358-2001-1-323.
Testo completoAbstract (sommario):
ABSTRACT A controlled oil spill experiment to determine natural recovery rates and the efficacy of potential remediation strategies in wetland ecosystems was initiated in June 1999 at a site on the St. Lawrence River, Canada dominated by Scirpus pungens. A weathered light crude oil (Mesa) was applied on 16 plots (5 m × 4 m) at the rate of 12 L per plot. Treatment of the plots included: natural attenuation (no treatment), nutrient amendment with granular ammonium nitrate and super triple phosphate, a similar treatment with plants continuously cut back (to evaluate the influence of plant growth on remediation), and a nutrient amendment treatment with sodium nitrate instead of ammonium nitrate. To elucidate the effect of nutrient amendments alone, four unoiled plots were fertilized with ammonium nitrate and triple super phosphate. Sediment samples were routinely recovered for chemical and toxicological analysis over a 21-week period that effectively covered the natural growth season of the plants. Significant changes in biological measures of habitat were observed. S. pungens, the dominant plant species, was tolerant to the oil, and its growth was significantly enhanced above that of the unoiled control by the addition of nutrients. Other biotest organisms (bacteria, Vibrio sp.,; invertebrates, Daphnia, Hyalella, and Viviparus sp.) provided additional evidence of both enhanced recovery and potential detrimental effects. GC-MS analysis could not resolve significant changes in the composition of the residual oil as a result of experimental treatments. This discrepancy in the detection of treatment efficacy between the chemical and biological methods may be due to induced tolerance to the contaminant hydrocarbons, changes in the bioavailability of the residual oil associated with stimulated plant growth, and detrimental effects of the type and quantity of bioremediation agents used.
49
Brandenburg, Karen, Laura Siebers, Joost Keuskamp, Thomas G. Jephcott e Dedmer B. Van de Waal. "Effects of Nutrient Limitation on the Synthesis of N-Rich Phytoplankton Toxins: A Meta-Analysis". Toxins 12, n. 4 (1 aprile 2020): 221. http://dx.doi.org/10.3390/toxins12040221.
Testo completoAbstract (sommario):
Eutrophication has played a major role in the worldwide increase of harmful algal blooms (HABs). Higher input of key nutrients, such as nitrogen (N) and phosphorus (P), can stimulate the growth of harmful algal species in freshwater, estuarine, and coastal marine ecosystems. Some HAB-forming taxa, particularly several cyanobacteria and dinoflagellate species, are harmful through the production of N-rich toxins that have detrimental effects on the environment and human health. Here, we test how changes in nutrient availability affect N-rich toxin synthesis in cyanobacteria and dinoflagellates using a meta-analysis approach. Overall, N-rich toxin content showed an increase with P limitation, while it tended to decrease with N limitation, but we also observed substantial variation in responses both within and across genera and toxin groups. For instance, in response to N limitation, microcystin content varied from a 297% decrease up to a 273% increase, and paralytic shellfish poisoning (PSP) toxin content varied from a 204% decrease to an 82% increase. Cylindrospermopsin, produced by N2-fixing cyanobacteria, showed no clear direction in response to nutrient limitation, and cellular contents of this compound may thus vary independently of nutrient fluctuations. Our results confirm earlier reported stoichiometric regulation of N-rich phytoplankton toxins, showing increased toxin content with an increase in cellular N:P ratios, and vice versa. Thus, changes in N-rich toxin content largely follow the changes in relative cellular N content. Consequently, although nutrient limitation may limit bloom biomass and thereby bloom toxicity, our results warn that P limitation can cause accumulation of cellular toxins and thus lead to unexpected increases in bloom toxicity.
50
Salifu, K. F., e V. R. Timmer. "Optimizing nitrogen loading of Picea mariana seedlings during nursery culture". Canadian Journal of Forest Research 33, n. 7 (1 luglio 2003): 1287–94. http://dx.doi.org/10.1139/x03-057.
Testo completoAbstract (sommario):
Plant growth and nutrient uptake response to increased fertilization can be conceptually described by cur vi linear relationships depicting phases of nutrient deficiency, sufficiency, luxury consumption, and toxicity to rationalize fertilizer prescriptions and improve nutrient diagnosis. We validated this model to determine optimum nitrogen storage of young black spruce (Picea mariana (Mill.) BSP). Container seedlings were supplied with a mixed nitrogenphosphoruspotassium (NPK) fertilizer at rates ranging from 0 to 80 mg N/seedling and reared in a greenhouse for one growing season. Plant growth and nutritional parameters of the plants exhibited classic responses of N deficiency, luxury consumption, and toxicity that were corroborated by vector diagnosis and appeared consistent with the conceptual model. Seedling biomass production was maximized at sufficiency (30 mg N/seedling), whereas N content of tissues peaked at the optimum loading rate (64 mg N/seedling). Toxicity occurred at the 80 mg N/seedling dose rate that increased plant N concentration (5%) but reduced growth (17%) and N content (14%) relative to the optimum level. Plant N content was raised 150% by optimum loading, exemplifying the effectiveness of this practice for building internal N reserves prior to planting. The newly validated model will help refine fertilizer recommendations and nutrient diagnosis for other species or cultural systems.