Showing papers in "Journal of Plant Nutrition in 1996"
TL;DR: In this paper, added silicon (Si) could significantly enhance dry matter yields of both salt-sensitive (Hordeum vulgare L.7) and salt-tolerant (Jian 4) barley cultivars under salt-stressed condition.
Abstract: Added silicon (Si) could significantly enhance dry matter yields of both salt‐sensitive (Hordeum vulgare L. Kepin No. 7) and salt‐tolerant (Hordeum vulgare L. Jian 4) barley cultivars under salt‐stressed condition. The dry matter yield of Kepin No.7 grown in the solution containing high Si (1.0 mM Si/L) and high salt (120 mM NaCl/L) was 18.0% greater than that of the plants treated with 120 mM NaCl/L alone. The dry matter yield of Jian 4 treated with low Si (0.5 mM Si/L) and high salt (120 mM NaCl/L) was found to increase by 15.2% compared with that of plants treated with 120 mM NaCl/L only. Silicon added could increase net photosynthetic rate of two barley cultivars grown in the solution containing 120 mM NaCl/L. The electrolytic leakage percentage was significantly lower in the leaves of two barley cultivars treated with 120 mM NaCl/L and 1.0 mM Si/L than in the leaves treated with 120 mM NaCl/L alone, which indicated that added Si resulted in a reduction of membrane permeability of salt‐stress...
231 citations
TL;DR: In this paper, the effects of different levels of cadmium (Cd) in the nutrient solution (0.0, 1.5, and 6.0 mg/L Cd) on the assimilation of nitrate (NO3 ) and the uptake and distribution of cationic nutrients in pea (Pisum sativum cv. Argona) seedlings were made.
Abstract: A study was made of the effects of different levels of cadmium (Cd) in the nutrient solution (0.0, 1.5, and 6.0 mg/L Cd) on the assimilation of nitrate (NO3 ‐) and the uptake and distribution of cationic nutrients in pea (Pisum sativum cv. Argona) seedlings. Cadmium treatment resulted in an accumulation of NO3 ‐ in the root, indicating an alteration in NO3 ‐ translocation to the shoot. This was related to a decrease in the nitrate reductase (NR) activity in the shoot, severely inhibiting NO3 ‐ assimilation, and associated to a reduction in fresh tissue weight and in their relative water content. The concentration of potassium (K) decreased in both root and shoot, but its relative distribution between those tissues was not affected by the presence of Cd. Among other cationic nutrients, manganese (Mn) was the most affected, its concentration constantly decreased concomitantly with the increase in Cd supply. The distribution of Mn between shoot and root revealed that more was accumulated in the shoo...
174 citations
TL;DR: In this paper, pepper (Capsicum annuum L.) plants grown in pots were irrigated with nutrient solutions containing 50, 75, and 100 mM NaCl or a control solution.
Abstract: Pepper (Capsicum annuum L.) plants grown in pots were irrigated with the nutrient solutions containing 50, 75, and 100 mM NaCl or a control solution. Salinity markedly decreased plant growth. Increasing salinity levels increased stomatal resistance and sodium (Na), chloride (Cl), proline contents of the plants. Potassium (K), total‐nitrogen (N), and chlorophyll content of the plants were decreased under high salinity conditions.
139 citations
TL;DR: Ryegrass and cabbage were relatively tolerant to Cd toxicity compared to white clover and maize, and plant species differed extensively.
Abstract: Solution culture experiments were conducted under controlled environmental conditions to determine the effects of cadmium(II) [Cd(II)] activity (0, 8, 14, 28, 42, and 54 μM) on influx (IN) into roots and transport (TR) from roots to shoots of zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca), magnesium (Mg), phosphorus (P), and sulfur (S) in ryegrass (Lolium perenne L.), maize (Zea mays L.), white clover (Trifolium repens L.), and cabbage (Brassica oleracea var. capitata L.). Shoot and root dry matter (DM) decreased with increased external Cd, and plant species differed extensively. Ryegrass and cabbage were relatively tolerant to Cd toxicity compared to white clover and maize. Influx and TR of Cu, Zn, Fe, Mn, Ca, and Mg were lower with increasing external Cd compared to controls, and species also differed. Influx and TR of P were enhanced in each species with up to 14 μM Cd, decreased in white clover and cabbage at higher Cd levels, while in maize and ryegrass continued to increase...
132 citations
TL;DR: In a field experiment, NH4NO3 applications (+N) to drought-stressed soybean resulted in biomass and N accumulation rates similar to those rates for an irrigated treatment without N fertilizer as mentioned in this paper.
Abstract: Drought in soybean [Glycine max (L.) Merr.] decreases yield‐related processes and N2 fixation is more sensitive to drought than are many other of these processes. Therefore, application of nitrogen (N) fertilizer may increase drought tolerance over those plants primarily dependent on N2 fixation. In a field experiment, NH4NO3 applications (+N) to drought‐stressed soybean resulted in biomass and N accumulation rates similar to those rates for an irrigated treatment without N fertilizer (‐N). In contrast, biomass and N accumulation rates were decreased for the ‐N treatment. N fertilization increased seed growth rate and decreased seed fill duration for irrigated and drought treatments. In the drought treatment, N application increased seed number per unit area, which resulted in higher yields. In a greenhouse experiment, fertilization with either KN03 or NH4C1 increased biomass and N accumulation rates during drought over those of plants dependent solely on N2 fixation. It was concluded that applic...
120 citations
TL;DR: The influence of different zinc (Zn) concentrations (1.5 to 1500 μM) on organic acid levels in roots and shoots of the Zn hyperaccumulator plant Thlaspi caerulescens was investigated as discussed by the authors.
Abstract: The influence of different zinc (Zn) concentrations (1.5 to 1500 μM) on organic acid levels in roots and shoots of the Zn‐hyperaccumulator plant Thlaspi caerulescens was investigated. In shoots, malate was the most abundant organic acid (164 to 248 μmol/g f.w.), followed by citrate, succinate, and oxalate. A significant correlation between soluble Zn and both malate and oxalate was observed in shoots, but not in roots. In shoots, a significant correlation between inorganic cation equivalents and organic acid anion equivalents was found. These observations and the finding, that organic acid concentrations were high even under suboptimal Zn supply (1.5 μM) suggest that in T. caerulescens the high organic acid concentration in shoots is a constitutive property. The variation of the organic acid concentrations seem to be a consequence of the cation‐anion balance rather than a specific Zn tolerance mechanism. The constitutively high organic acid concentration may be responsible for the high Zn and iro...
112 citations
TL;DR: Nickel decreased both IN and TR of Zn, Cu, Ca, and Mg, but only TR of Fe and Mn in white clover, while cabbage and ryegrass showed markedly decreased by Ni >30 μM, whereas IN andTR of P increased with Ni treatment.
Abstract: Nickel (Ni) is an essential micronutrient for higher plants but is toxic to plants at excess levels. Plant species differ extensively for mineral uptake and accumulation, and these differences often help explain plant tolerances to mineral toxicities/deficiencies. Solution culture experiments were conducted under controlled conditions to determine the effects of Ni on influx into roots (IN) and transport from roots to shoots (TR) of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), calcium (Ca), magnesium (Mg), phosphorus (P), and sulfur (S) in white clover (Trifolium repens L.), cabbage (srassica oleracea van capitata L.), ryegrass (Lolium perenne L.), and maize (Zea mays L.). Nickel decreased both IN and TR of Zn, Cu, Ca, and Mg, but only TR of Fe and Mn in white clover. Both IN and TR of Cu, Fe, Mn, Mg, and S were markedly decreased by Ni >30 μM in cabbage, whereas IN and TR of P increased with Ni treatment. For ryegrass, TR of Cu, Fe, Mn, Ca, and Mg was decreased, but IN of these elements ex...
94 citations
TL;DR: In this paper, the influence of nitrogen on dry matter accumulation and yield in cotton is well documented, but its effects on carbon assimilation and transpiration are less clear, and the results of a study were to characterize leaf photosynthetic and stomatal responses of Pima cotton.
Abstract: The influence of nitrogen (N) on dry matter accumulation and yield in cotton is well documented, but its effects on carbon (C) assimilation and transpiration are less clear. The objectives of this study were to characterize leaf photosynthetic and stomatal responses of Pima cotton (Gossypium barbadense L., cv. S‐6) plants, grown under different N nutritional regimes. Pima cotton was grown in pots under natural environmental conditions. Varying N regimes were imposed on 20‐day‐old plants by fertilizing with nutrient solutions containing 0, 0.5, 1.5, and 6 mM of nitrate (NO3) concentrations. Net carbon dioxide (CO2) assimilation rates, stomatal conductance, internal CO2 partial pressures, transpiration rates, leaf carbohydrate status, ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco) activities, and leaf N concentrations were determined in the youngest fully expanded leaves. Net photosynthetic rates, stomatal conductance and transpiration were positively correlated with leaf N concentration...
87 citations
TL;DR: In plants grown without Zn, release of phytosiderophores progressively increased with the onset of visual Zn deficiency symptoms, such as inhibition of shoot elongation and appearance of chlorotic and necrotic patches on leaves.
Abstract: The effect of the zinc (Zn) nutritional status on the rate of phyto‐siderophore release was studied in three wild grass species (Hordeum murinum, Agropyron orientale, and Secale cereale) grown in nutrient solution under co‐trolled environmental conditions. These wild grasses are highly “Zn‐efficient”; and grow well on severely Zn‐deficient calcareous soils in Turkey (DTPA‐extractable Zn was 0.12 mg/kg soil and CaCO3 was 37%). In all wild grasses studied, Zn deficiency reduced shoot growth but had no effect on root growth. Low amounts of phytosiderophores were released from roots of all wild grasses adequately supplied with Zn. In plants grown without Zn, release of phytosiderophores progressively increased with the onset of visual Zn deficiency symptoms, such as inhibition of shoot elongation and appearance of chlorotic and necrotic patches on leaves. Compared to Zn‐sufficient plants, phytosiderophore release increased 18–20‐fold in deficient plants. HPLC analysis of root exudates showed that the...
78 citations
TL;DR: In this paper, the authors found that canola tolerant to arsenic (As) when grown in hydroponic solutions and generally sensitive to As when growing in soil, and that chlorosis, wilting, and stunted growth occurred in canola at the highest As rate in two of the three soils used.
Abstract: Separate studies found canola tolerant to arsenic (As) when grown in hydroponic solutions and generally sensitive to As when grown in soil. Fourteen‐day‐old canola was transferred to pots containing either soil or nutrient solution and then grown for an additional 14 days in a growth chamber at different times for the two different media. Plants were grown in 0.25‐strength Hoagland's solution containing either 0, 0.27, 6.67, or 13.3μM As or in three soils with As added at rates of 0,5, and 10 mg.kg‐1. Soil‐solution As concentrations were determined via column displacement and were the same or less (0.147 to 4.27μM) than the hydroponic As concentrations. Soil‐solution phosphorus (P) concentrations were determined in the same manner and averaged 9.28μM P compared to 500μM P from the hydroponic solutions. Chlorosis, wilting, and stunted growth—symptoms of As toxicity—occurred in canola at the highest As rate in two of the three soils used. Dry‐matter yields from the third soil were low from all trea...
73 citations
TL;DR: Field selection for resistant cultivars is complicated by heterogeneous soil and environmental conditions, and breeding programs implementing these techniques are slow and have reached a plateau.
Abstract: Iron (Fe)‐deficiency chlorosis is widespread in numerous crops grown on calcareous soils and results in significant yield losses. Examples of affected crops are soybean (Glycine max L.), chickpea (Cicer arietinum L.), peanut (Arachis hypogaea L.), dry bean (Phaseolus vulgaris L.), tomato (Lycopersicon esculentum Mill.), oat (Avenae sativa L.), wheat (Triticum aestivum L.), sorghum [Sorghum bicolor (L.) Moench], corn (Zea mays L.), rice (Oryza sativa L.), and various fruit species. Other than with high return fruit crops, the problem is not economically solved with fertilizer application. A more reasonable solution is the introduction of genotypes which are resistant to Fe‐deficiency chlorosis development (physiologically ‘Fe efficient')‐ Field selection for resistant cultivars is complicated by heterogeneous soil and environmental conditions, and breeding programs implementing these techniques are slow and have reached a plateau. The physiological responses to Fe‐deficiency stress include release...
TL;DR: In this article, the effects of salinity due to sodium chloride (NaCl) and nitrogen (N) concentration in the nutrient solution were studied with sweet pepper plants and four saline treatments combined with two N fertilization were used.
Abstract: The effects of salinity due to sodium chloride (NaCl) and nitrogen (N) concentration in the nutrient solution were studied with sweet pepper plants. Four saline treatments combined with two N fertilization were used. Nitrate‐nitrogen (NO3 ‐‐N) presence in the nutrient solution produced an increase of sodium (Na) and potassium (K) contents in leaves as well as N. Salinity promoted a reduction of K, phosphorus (P) and Ca and increased the Na concentration in leaves. Calcium (Ca) concentrations were lower in the higher NO3 ‐‐N treatment although N level was reached adding calcium nitrate and salinity increased P, K, Na, Ca, and magnesium (Mg) contents in fruits. Yield was increased in the highest N treatment.
TL;DR: In this paper, a solution culture experiment was conducted under controlled conditions to determine influx (IN) into roots, transport (TR) from roots to shoots, and accumulation of Ni in four plant species grown at different Ni levels.
Abstract: Plant tolerance to nickel (Ni) toxicity depends on plant differences for uptake and distribution within tissues. Differences among and within species for Ni tolerance/accumulation might be used to identify or develop plants for remediation of high Ni soil conditions. Solution culture experiments were conducted under controlled conditions to determine influx (IN) into roots, transport (TR) from roots to shoots, and accumulation of Ni in four plant species grown at different Ni levels. White clover (Trifolium repens L.) had high dry matter (DM) at high Ni levels because of its low IN and TR of Ni. At Ni levels <60 μM, maize (Zea mays L.) had high DM probably because of its low TR even though it had high IN of Ni. Ryegrass (Lolium perenne L.) was sensitive to Ni toxicity because of its high IN and TR of Ni. The sensitivity of cabbage (Brassica oleracea var. capitata L.) to Ni toxicity was correlated with high TR even though it had low IN of Ni. Nickel accumulation in shoots was relatively high for c...
TL;DR: These genotypic differences in susceptibility to zinc (Zn) deficiency were less severe in the bread wheats Gerek‐79 and particularly Dagdas‐94, while the others are highly susceptible to Zn deficiency, when grown on severely Zn deficient calcareous soils in Turkey.
Abstract: Using six bread wheat genotypes (Triticum aesttvum L. cvs. Dagdas‐94, Gerek‐79, BDME‐10, SBVD 1–21, SBVD 2–22 and Partizanka Niska) and one durum wheat genotype (Triticum durum L. cv. Kunduru‐1149) experiments were carried out to study the relationship between the rate of phytosiderophore release and susceptibility of genotypes to zinc (Zn) deficiency during 15 days of growth in nutrient solution with (1 μM Zn) and without Zn supply. Among the genotypes, Dagdas‐94 and Gerek‐79 are Zn efficient, while the others are highly susceptible to Zn deficiency, when grown on severely Zn deficient calcareous soils in Turkey. Similar to the field observations, visual Zn deficiency symptoms, such as whitish‐brown lesions on leaf blades occurred first and severely in durum wheat Kunduru‐1149 and bread wheats Partizanka Niska, BDME‐10, SBVD 1–21 and SBVD 2–22. Visual Zn deficiency symptoms were less severe in the bread wheats Gerek‐79 and particularly Dagdas‐94. These genotypic differences in susceptibility to ...
TL;DR: In this paper, the relative importance of osmotic and specific ion effect on plant growth seems to vary depending on the salt tolerance of the plant under study, and the importance of specific ion effects arc the most frequently mentioned mechanisms by which saline substrates reduce plant growth.
Abstract: Osmotic and specific ion effects arc the most frequently mentioned mechanisms by which saline substrates reduce plant growth. However, the relative importance of osmotic and specific ion effect on plant growth seems to vary depending on the salt tolerance of the plant under study. Pea plants grew in Na2SO4 and NaCl treatments up to the ‐1800 kPa level, but only in the Na2CO3 treatments up to the ‐1200 kPa level. The higher toxicity of Na2CO3 compared to that of Na2SO4 and NaCl treatments was observed. This point was made clear by their effects on fresh dry matter and water content of the pea plants. The value of osmotic pressure was markedly increased with increasing NaCl concentration in the soil and under the moderate levels of the Na2SO4 treatments, while it was significantly decreased with increasing Na2CO3 concentration. This was also related to the accumulation of soluble saccharides, proteins, amino acids, and prolines in plants treated with NaCl and in plants grown under Na2SO4, with the ...
TL;DR: In this article, the influence of elevated levels of micronutrients on the growth and flowering of French marigold (Tagetes patula L.) was investigated, where plants were grown with nutrient solution containing 0.25, 0.5, 1, 2, 3, 4, 5, or 6 mM boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn) and toxicity development was monitored.
Abstract: The influence of elevated levels of micronutrients on the growth and flowering of French marigold (Tagetes patula L.) was investigated. Plants were grown with nutrient solution containing 0.25, 0.5, 1, 2, 3, 4, 5, or 6 mM boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn) and toxicity development was monitored. The threshold micronutrient concentrations that induced visible foliar toxicity symptoms were 0.5 mM B, 4 mM Cu, 4 mM Fe, 2 mM Mn, 1 mM Mo, and 5 mM Zn. The dry matter yields during the 5 week experimental period were reduced when micronutrient concentrations exceeded 0.5 mM B, 3 mM Cu, 3 mM Fe, 6 mM Mn, 0.5 mM Mo, and 5 mM Zn in the fertilizer solution. Leaf chlorophyll contents decreased when the nutrient solution concentrations of Cu, Fe, and Mn were greater than 0.5 mM, 3 mM, and 2 mM, respectively. Visual toxicity symptoms of the six micronutrients were characterized.
TL;DR: In this paper, the influence of zinc supply on mineral nutrition in T. caerulescens was investigated, in order to establish the extent to which growth stimulation by high Zn supply is related to changes in the levels of other essential nutrients.
Abstract: Thlaspi caerulescens, a metallophyte that is able to accumulate up to 4% zinc (Zn) in leaf dry matter, has attracted much attention for its possible use in phytoremediation of metal contaminated soils. In the present study, the influence of Zn supply on mineral nutrition in T. caerulescens was investigated, in order to establish the extent to which growth stimulation by high Zn supply is related to changes in the levels of other essential nutrients. The plants were exposed to nutrient solutions containing 1.5, 100, 500, 750, 1000, or 1500 μM Zn. Zinc supply significantly influenced root and shoot concentrations of essential nutrients, but excepting Zn, the concentrations stayed within the range considered adequate for optimum growth in Brassicaceae crops. Best performance was achieved with the supply of 500 μM Zn. Growth stimulation by this treatment was accompanied by increased translocation of iron (Fe) from root to shoot and a significant correlation between shoot dry weight and Fe concentrati...
TL;DR: In this paper, the feasibility of using a hand held chlorophyll meter (SPAD 502, Minolta Co. Ltd., Japan) to monitor the status of tall fescue (Festuca arundinacea Schreb).
Abstract: The nitrogen (N) status of a crop can be used to predict yield and supplemental N fertilizer requirements, and rapid techniques for evaluating the N status of crops are needed. A study was conducted to determine the feasibility of using a hand held chlorophyll meter (SPAD 502, Minolta Co. Ltd., Japan) to monitor N status of tall fescue (Festuca arundinacea Schreb.). Four diverse tall fescue genotypes were grown at three locations in Alabama and fertilized at four N‐rates from 0 to 336 kg ha‐1. A similar experiment was conducted in the greenhouse using soil from the same field sites. Chlorophyll meter readings (SPAD) were taken, and extractable chlorophyll content, tissue N concentration and dry matter yield were determined at harvest. SPAD, extractable chlorophyll content, tissue N concentration, and dry matter yield increased quadratically (0.67 < R2 < 0.99) with increasing N fertilization in both experiments. All genotypes responded similarly to applied N, with some differences in magnitude. Re...
TL;DR: It is still an open question whether plant ferritin can serve as a long distance Fe shuttle between sources and sink organs, or whether its function is limited to the metabolism of plastics.
Abstract: The iron‐storage protein ferritin, which is localized in the plastics in plants, plays roles during development and under stress conditions, due to its ability to buffer iron (Fe) fluxes, keeping this element temporary in a safe and bioavailable form. Ferritin Fe of leaves or nodules may serve as a preliminary pool for the building up of Fe containing proteins. Ferritin could also play a general role in stress response in plants. Concerning stress, it is more specifically involved in the buffering of Fe in the chloroplast during recovery of Fe deficiency and as an important component to protect plastics against Fe‐mediated oxidative stress. It is still an open question whether plant ferritin can serve as a long distance Fe shuttle between sources and sink organs, or whether its function is limited to the metabolism of plastics.
TL;DR: In this article, the effect of Fe fertilizer on the plant micronutrients was investigated in calcareous soils. But, although a positive response to iron (Fe) is, usually, expected in calcaous soils, this has not always been always the case; and in some instances a depressing effect has been observed.
Abstract: Although a positive response to iron (Fe) is, usually, expected in calcareous soils; this has not been always the case; and in some instances a depressing effect has been observed. An induced micronutrient imbalance is suspected. This experiment was designed to study the effect of Fe fertilizer on the plant micronutrients. Twenty three highly calcareous soils (18–46% calcium carbonate equivalent; pH 7.7–8.4; and a wide range of extractable Fe) from southern Iran were used in an eight‐week greenhouse experiment to study the effect of Fe fertilizers on soybean [Glycine max (L.) Merr.] growth and chemical composition. The statistical design was a 23 × 3 factorial arranged in a completely randomized block with three replications. Treatments consisted of 23 soils and three levels of applied Fe (0, 10, and 20 mg Fe/kg as FeEDDHA). Uniform doses of nitrogen (N), phosphorus (P), copper (Cu), manganese (Mn), and zinc (Zn) were applied to all pots. Dry matter (DM) and micronutrients concentrations and upta...
TL;DR: Identification of plant attributes that improve the performance of tropical forage ecotypes when grown as monocultures or as grass+legume associations in low fertility acid soils will assist the development of improved forage plants and pasture management technology.
Abstract: Identification of plant attributes that improve the performance of tropical forage ecotypes when grown as monocultures or as grass+legume associations in low fertility acid soils will assist the development of improved forage plants and pasture management technology. The present work compared the shoot and root growth responses of four tropical forages: one grass and three legumes. The forages were grown in monoculture or in grass+legume associations at different levels of soil phosphate. Two infertile acid soils, both Oxisols, were used: one sandy loam and one clay loam. They were amended with soluble phosphate at rates ranging from 0 to 50 kg ha‐1. The forages, Brachiaria dictyoneura (grass), Arachis pintoi, Stylosanthes capitata and Centrosema acutifolium (legumes), were grown in large plastic containers (40 kg of soil per container) in the glasshouse. After 80 days of growth, shoot and root biomass production, dry matter partitioning, leaf area production, total chlorophyll content in leaves,...
TL;DR: In this paper, a multifactorial trial was conducted, where tomato plants, grown in rockwool in a circulating system, were fed with 0.75, 1.25, and 1.75 mM phosphate (P) and two calcium (Ca) levels resulting in 4.0 and 11.2 mM Ca in the leachate.
Abstract: Blossom‐end rot is not the result of a single factor, but from the interaction of several factors. To prove this and to get information on how to lower the detrimental effect of blossom‐end rot, a multifactorial trial was conducted. Tomato plants, grown in rockwool in a circulating system, were fed with 0.75, 1.25, and 1.75 mM phosphate (P) and two calcium (Ca) levels resulting in 4.0 and 11.2 mM Ca in the leachate. Two air humidity levels were maintained. The low Ca, P, and humidity resulted in higher levels of blossom‐end rot than the higher levels of these factors. The increasing effect of low P on blossom‐end rot could be the result of the fact that at low P, ammonium (NH4) addition was higher than at high P, because at low P, the pH tended to increase and pH control was done by adding NH4. However, it is possible that an effect of P remains. The combination of the factors at the low levels gave rise to 59% blossom‐end rot. In this treatment, plants suffered in course of time from severe leaf...
TL;DR: In this article, the authors characterized and quantified the chemical form of cadmium (Cd) in intercellular solutions of the apparent free space (AFS) of roots and leaves of bush bean plants.
Abstract: We characterized and quantified the chemical form of cadmium (Cd) in intercellular solutions of the apparent free space (AFS) of roots and leaves of bush bean plants. Plants were grown in sand and treated daily for five days with Hoagland nutrient solution containing, respectively, 0.5 and 1 mM Cd(NO3)2. The intercellular solution was collected by infiltration‐extraction procedure using successively distilled water, 5 mM CaCl2, and 5 mM EDTA in order to collect separately the water soluble, exchangeable, and complexed Cd. The ability of extradant solutions to remove Cd from the AFS of roots and leaves was: H2O < CaCl2 ≪ EDTA, confirming that most of Cd was bound at the cell wall. Voltarimetric technique showed that water‐soluble Cd in intercellular solutions of the root and leaf tissues was as the Cd2+ ion, suggesting that Cd might be taken up by the roots and transported to leaves as the free ion.
TL;DR: Barley, Hordeum vulgare L., is extremely sensitive to excess soluble or exchangeable aluminum (Al) in acid soils having pH values below about 5.5 as discussed by the authors.
Abstract: Barley, Hordeum vulgare L., is extremely sensitive to excess soluble or exchangeable aluminum (Al) in acid soils having pH values below about 5.5. Aluminum tolerant cultivars are needed for use in rotations with potatoes which require a soil pH below 5.5 for control of scab disease. They are also potentially useful in the currently popular “low input, sustainable agriculture (LISA)”; in which liming even the plow layer of soil is not always possible or cost effective, or in situations where surface soils are limed but subsoils are acidic and Al toxic to roots. Ten barley cultivars were screened for Al tolerance by growing them for 25 days in greenhouse pots of acid, Al‐toxic Tatum subsoil (clayey, mixed, thermic, typic Hapludult) treated with either 750 or 4000 μg•g‐1 CaCO3 to produce final soil pH values of 4.4 and 5.7, respectively. Based on relative shoot dry weight (weight at pH 4.4/weight at pH 5.7 X 100), Tennessee Winter 52, Volla (England), Dayton and Herta (Denmark) were significantly mo...
TL;DR: In contrast to the wild form which as high nicotianamine synthase activity, no activity of the enzyme could be detected in roots or shoots of ‘chloronerva’, regardless of the iron nutritional status of the plants.
Abstract: Nicotianamine is proposed to play a key role in iron (Fe) metabolism in plants. In graminaceous plants nicotianamine is the precursor for phytosiderophores, and the activity of the nicotianamine synthase is strongly enhanced under Fe deficiency. The tomato mutant ‘chloronerva’ (Lycopersicon esculentum Mill, cv. chloronerva) lacks nicotianamine and has a disturbed Fe homeostasis. Our objective was to compare nicotianamine synthase activity of the mutant ‘chloronerva’ with the wild form ('Bonner Beste'). In contrast to the wild form which as high nicotianamine synthase activity, no activity of the enzyme could be detected in roots or shoots of ‘chloronerva’, regardless of the iron nutritional status of the plants. This finding might allow comparison of promoter regions of the genes of ‘chloronerva’, ‘Bonner Beste’, and graminaceous species to clarify the regulatory mechanism of gene expression by the Fe nutritional status in graminaceous species.
TL;DR: Leaf chlorophyll readings were higher in +VAM than in ‐VAM plants and followed a sequence similar to DM, and plants colonized with Gi had higher leaf Fe, phosphorus (P), and zinc (Zn) concent...
Abstract: Vesicular‐arbuscular mycorrhizal fungi (VAMF) are known to improve the mineral nutritional status of plants. Since information on effects of VAMF on plant iron (Fe) nutrition is limited, an Fe deficient‐susceptible maize (Zea mays L., ysi/ysi) was grown on alkaline Quinlan (Typic Ustochrept, pH 8.0) and Ulysses (Aridic Haplustoll, pH 7.8) soils with Glomus VAMF isolates G. etunicatum WV579A (Ge), G. diaphanum WV579B (Gd), and G. intraradices WV894 (Gi) to determine plant growth responses to VAMF associations and efficacy of these VAMF isolates to enhance Fe acquisition. Shoot and root dry matter (DM) were higher in mycorrhizal (+VAM) then in nonmycorrhizal (‐VAM) plants, and followed a sequence of Ge > Gd ≥ Gi > ‐VAM. Root DM of Ge plants was higher than other +VAM plants. Even though relatively low, leaf chlorophyll (SFAD unit) readings were higher in +VAM than in ‐VAM plants and followed a sequence similar to DM. Plants colonized with Gi had higher leaf Fe, phosphorus (P), and zinc (Zn) concent...
TL;DR: In this article, the authors compared the SAM synthetase activities between Fe-deficient and Fe-sufficient barley roots and found no difference in the amount of mRNA produced by the two groups.
Abstract: S‐adenosyl‐L‐methionine (SAM) synthetase, which catalyzes methionine to SAM, is one of the enzymes involved in the biosynthesis of the mugineic acid‐family phytosiderophores (MAs). The MAs are secreted from grass roots under iron (Fe)‐deficient conditions. We compared the SAM synthetase activities between Fe‐deficient and Fe‐sufficient barley roots. However, no difference was observed. Then we performed Northern hybridization analysis between Fe‐deficient and Fe‐sufficient barley tissues by a cDNA fragment of SAM synthetase isolated from barley. No increase in the amount of mRNA was detected in the Fe‐deficient barley roots as compared to the Fe‐sufficient ones. It was suggested that the first step in the phytosiderophore biosynthesis induced under the Fe‐deficiency is not SAM synthetase, but NA synthase and the second induced step is NA aminotransferase.
TL;DR: All the detected nutrient accumulations increased abruptly during leaf ontogeny and leaf maturation until a maximum level, whereas Ca, Fe, Mn, and Zn concentrations were at higher levels as compared to those previously reported.
Abstract: The dry weight accumulation per leaf as well as the concentration per gram of dry weight and the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined in walnut tree leaves (Juglans regia L.) during a complete life cycle. Additionally, the dynamics of plant nutrient concentration in leaf petiole sap and carbohydrate accumulation in leaves were studied in relation to the main life cycle events of the walnut tree. Total N, P, K, Cu, and Zn concentrations decreased, whereas that of Ca, Mg, and Mn increased during the season. Iron concentration fluctuated around a mean value. Total N, P, K, Mg, and Cu concentrations detected in younger mature leaves were at the sufficient level, whereas Ca, Fe, Mn, and Zn concentrations were at higher levels as compared to those previously reported. All the detected nutrient accumulations increased abruptly during leaf ontogeny and leaf maturation until a maximu...
TL;DR: In this article, the effectiveness of three local liming materials: basic slag (a byproduct of iron and steel industry), cement flue dust (a waste product of cement factory), and ground limestone was compared with that of imported hydrated lime in a greenhouse study using acid soils from two sites in Southern Nigeria.
Abstract: The effectiveness of three local liming materials: basic slag (a byproduct of iron and steel industry), cement flue dust (a waste product of cement factory), and ground limestone was compared with that of imported hydrated lime in a greenhouse study using acid soils from two sites in Southern Nigeria. The soils were taken from Onne, near Port Harcourt in Rivers State and Epe near Lagos in Lagos State. The soils were classified as Typic paleudult and Typic udipsamment, respectively. The results show that the four liming materials were capable of neutralizing soil acidity. Their relative effectiveness was in the order: hydrated lime > basic slag > cement flue dust > ground limestone. Uptake of phosphorus (P), potassium (K), and calcium (Ca), and dry matter yield increased with increasing lime rates up to 500 and 1,000 mg Ca/kg soil for Epe and Onne soils, respectively. The lime requirements of the two soils are in the order of the aluminum (Al) saturation of the effective cation exchange capacity (...
TL;DR: In this article, the authors examined the petiole NO3-N dynamics during the growing season for both chipping and table stock varieties and found that most consistent NO3−N readings could be obtained by collecting tissue samples between 1100 and 1400 hours of the day.
Abstract: Petiole nitrate nitrogen (NO3‐N) concentrations have been successfully used in Northwestern New Mexico to make timely nitrogen (N) recommendations for irrigated potatoes. However, a quick test and consistent sampling time is needed to precisely determine fertigation and to prevent over fertilization, especially in sandy soils. This study examined the petiole NO3‐N dynamics during the growing season for both chipping and table stock varieties. Readings from a quick in‐field sap NO3‐N meter were highly correlated with NO3‐N indications using the conventional laboratory method. The sap NO3‐N meter can significantly reduce testing turnaround time and has great potential for potato N management. Results showed that most consistent NO3‐N readings could be obtained by collecting tissue samples between 1100 and 1400 hours of the day.