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IntroductionGuar is a one-year plant from the Fabaceae family and tolerates dry and salty conditions, and therefore can be used as a high potential for production. The planting date is one of the most critical factors in the cultivation and production of crops. This is especially important for plants being introduced for cultivation in a region for the first time, as research on the optimal planting date for that area is essential. Mineral nutrition of agricultural plants is one of the most important aspects of production, and among the micronutrient elements, zinc has a fundamental role in the catalytic activities of proteins and enzymes involved in biological processes in growing plants. Facilitating the activity of many enzymes in the plant depends on the presence of appropriate amounts of zinc. Considering the research gap related to the effect of planting date and application of zinc sulfate in the study area and in order to compare with other different regions of the country, as well as the importance and development of new plant cultivation in the country, this research was carried out. Materials and MethodsTo investigate the response of morphological traits and yield components of guar plant (Cyamopsis tetragonoloba L.) on different planting dates and zinc sulfate levels in the KhorramAbad region in the 2020 crop year, was carried out. This exfaiment was carried out as a split plot in the form of a basic design of randomized complete blocks with three replications. In the main plots, the planting date factor was set at three levels (including May 1, 20, and June 10), and in the secondary plots, zinc sulfate foliar treatments were applied at four levels: zero, 20, 40, and 60 kg fa hectare of zinc sulfate applied. The amount of zinc sulfate in each plot was mixed with soil based on the treatment levels and the area of each plot. According to the test results, the soil was not deficient in phosphorus and potassium elements, so only urea fertilizer was used. Results and Discussion The results showed that the effect of planting date, zinc sulfate, and their interaction on plant height traits, the number of sub-branches fa plant, leaf dry weight, and specific leaf surface area were significant. Also, the effect of planting date and zinc sulfate on the number of pods fa m2, grain yield, and leaf area index were significant. Planting guar on June 10 resulted in the highest number of pods fa m2 (1998.6 pods) and the number of seeds fa m2 (13920 seeds), and on the other hand, despite the positive correlation between them and seed yield, the highest seed yield on this date, 3889.7 kg fa hectare was planted. The highest number of leaves fa plant (846.75 leaves) and leaf area index (6.02) were obtained on the planting date of June 10 and with the application of 60 kg fa hectare of zinc sulfate (689.44 leaves and 5.43, respectively). The highest amount of dry weight of leaves fa plant in the treatment of application of 20 kg.ha-1 of zinc sulfate was 21.08 grams and the highest specific surface area of guar leaf was obtained on the planting date of May 20 and in the treatment of no application of zinc sulfate (0.47). The presence of a positive correlation between growth characteristics, yield components, and leaf characteristics with grain yield also indicated the positive effect of zinc sulfate application and planting date of 10 June in increasing these characteristics and as a result increasing grain yield. ConclusionsWith the delay in planting and the application of zinc sulfate fertilizer, which led to an increase in the grain yield components in the guar plant, the grain yield also increased. According to the results of this study, it can be said that to achieve the maximum seed yield in the guar plant in the Khorramabad region, this plant can be cultivated on the planting date of 10 Khordad. Also, considering that there was no significant difference in terms of grain yield among the different levels of zinc sulfate application, in order to achieve the highest grain yield with the lowest amount of cost, it is possible to use 20 kg of zinc sulfate fa hectare. [ABSTRACT FROM AUTHOR]

Biofilm obtained from Bacillus subtilis subsp. spizizenii inoculated on vegetable seeds has been shown to have plant growth-promoting capacity. Seed inoculation with biofilm produced by this strain could also reduce the adverse effects on plant growth caused by soil or substrate heavy metal overabundance. Therefore, the objective of this work was to evaluate the impact of biofilm inoculated on tomato (Solanum lycopersicum L.) seeds, which were planted on a substrate with artificially added zinc. First, seeds of the Río Grande tomato variety were exposed to increasing zinc concentrations, namely: 50, 100, 200, and 400 ppm, with and without bacterial biofilm inoculation. Zinc addition and seed inoculation affected germination parameters. For example, an extra 200 and 400 ppm of zinc led to high toxicity. Biofilm inoculation, however, reduced the noxious effects of excess zinc, bringing acute toxicity down to moderate. Then, tomato plants growing from inoculated and non-inoculated seeds were cropped for 4 months in both substrates with 400 ppm zinc and without added zinc. Extra zinc addition significantly (p < 0.05) reduced tomato root and shoot biomass, plant height, and fruit number at harvest time. However, seed biofilm inoculation avoided the harmful effect of zinc on plant growth parameters, fruit yield, and fruit quality. The roots and shoots of plants growing on contaminated substrates showed very noticeable increases in zinc levels compared to the control, while fruits only showed a much weaker zinc gain, even if this was significant (p < 0.05). Moreover, root shoot and fruit concentrations of elements other than zinc, (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, lead, and cadmium) were not or only weakly affected by the addition of this metal to the substrate. In summary, the biofilm of B. subtilis proved to be effective as a bioinoculant to alleviate negative effects on tomatoes cropped in a substrate with excess zinc. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated the impact of phosphorus and zinc on both yield and quality parameters of chickpea. Topics discussed include importance of maintaining a favourable balance between phosphorus and zinc to the optimum growth of plants, nutrient content and uptake of chickpea, and effect of phosphorus and zinc levels on nutrient uptake by chickpea.

This research focused on the evaluation of twelve newly bred rice genotypes with diverse morphological traits under aerobic cultivation to develop strategies for water conservation while maintaining grain productivity and quality. The experiment was conducted during the summer season of 2016, employing a Randomized Complete Block Design (RCBD) with wetland cultivation as a control. For analysis, various vegetative and reproductive traits namely, Plant height, Number of Tillers, Shoot Weight, Days to 50% flowering, Days to Maturity, Number of Productive Tillers, Panicle Length, Grain Weight, Length of the seed, Breadth of the seed, Ratio of Length and Breadth of the Seed, and Test weight of 100 seeds were recorded. Data on analysis of variance revealed the significant difference for days to flowering, maturity, plant height, panicle length, test weight, and grain yield under aerobic and wetland cultivation methods during the summer season, 2016, suggesting these traits are under high genetic control. Genetic parameters such as percentage of GCV, PCV, Heritability, and GAM were estimated across 13 parameters comprising vegetative and reproductive characters. The findings suggest a considerable amount of genetic variability for most traits, providing a foundation for the potential implementation of an effective selection procedure in breeding new rice varieties within the selected genotypes. [ABSTRACT FROM AUTHOR]

A field experiment on the effect of zinc and molybdenum application on the yield of lentil was carried out at The University of Agriculture Peshawar during the Rabi season of 2021. The experiment was carried out in a randomised complete block design with three replications. Four levels of molybdenum (0, 1, 2 and 3 kg ha-1) and 0.5% zinc foliar spray at different intervals of lentil crop (control, 50 days after sowing, 100 days after sowing, 50 days after sowing + 100 days after sowing) were tested in the experiment. The results revealed that 3 kg ha-1 of molybdenum enhanced plant height (55 cm), nodules plant-1 (25), branches plant-1 (7), days to flowering (107) and maturity (159), dry matter of leaves at the flowering stage (64 g m-2), dry matter of leaves at the maturity stage (113 g m-2), dry matter of branches at the physiological maturity stage (304 g m-2), dry matter of pods at the maturity stage (439 g m-2), pods plant-1 (92), seeds pod-1 (2.0), 1000-seed weight (31 g), biological yield (3207 kg ha-1), and seed yield (1002 kg ha-1). Zinc foliar spray (0.5%) at 50 days after sowing + 100 days after sowing of lentil crop improved the dry matter of leaves at the flowering stage (62 g m-2), days to first flowering (109), days to physiological maturity (157), dry matter of leaves at the physiological maturity stage (111 g m-2), dry matter of pods at the physiological maturity stage (435 g m-2), pods plant-1 (91), 1000 seed weight (32 g), biological yield (3236 kg ha-1) and seed yield (1026 kg ha-1). Lastly, scatterplots revealed a significant correlation of grain and biological yield with their components. It is concluded that molybdenum application at a rate of 3 kg ha-1 and 0.5% zinc foliar spray at 50 days after sowing + 100 days after sowing of the lentil crop increased seed yield and is thus recommended for the Peshawar region. [ABSTRACT FROM AUTHOR]

The relationship between zinc mineral nutrition and plant growth-promoting bacteria (PGPB) is pivotal in enhancing agricultural productivity, especially in tropical regions characterized by diverse climatic conditions and soil variability. This review synthesizes and critically evaluates current knowledge regarding the synergistic interaction between zinc mineral nutrition and PGPB in tropical agricultural systems. Zinc is an essential and fundamental micronutrient for various physiological and biochemical processes in plants. Its deficiency affects plant growth and development, decreasing yields and nutritional quality. In tropical regions, where soil zinc availability is often limited or imbalanced, the PGPB, through different mechanisms such as Zn solubilization; siderophore production; and phytohormone synthesis, supports Zn uptake and assimilation, thereby facilitating the adverse effects of zinc deficiency in plants. This review outlines the impacts of Zn–PGPB interactions on plant growth, root architecture, and productivity in tropical agricultural systems. The positive relationship between PGPB and plants facilitates Zn uptake and improves nutrient use efficiency, overall crop performance, and agronomic biofortification. In addition, this review highlights the importance of considering indigenous PGPB strains for specific tropical agroecosystems, acknowledging their adaptability to local conditions and their potential in sustainable agricultural practices. It is concluded that Zn fertilizer and PGPBs have synergistic interactions and can offer promising avenues for sustainable agriculture, addressing nutritional deficiencies, improving crop resilience, and ensuring food security. [ABSTRACT FROM AUTHOR]

Antimicrobial hybrid polymer composites are developed for application in floating solar power plants. To avoid the degradation of the floater because of microbes living in the water as well as possible biofouling, zinc oxide (ZnO) is used as an antimicrobial agent, varying the weight percent (1, 2, and 3 wt%) within the high-density polyethylene (HDPE) matrix, along with carbon black (CB) as a reinforcing agent (1, 1.5, 2, and 2.5 wt%). Escherichia coli (facultative anaerobic) and Pseudomonas aeruginosa (aerobic-facultatively anaerobic) gram-negative bacteria formed a biofilm on HDPE in a 96-well plate for 5 days. In vitro, biofilm formation was determined by measuring absorbance (A420) in crystal violet dye, and the colony-forming unit (CFU) was determined by the spread plating technique. The biofilm formation and disruption are observed through a scanning electron microscope (SEM), where both the CFU and the SEM revealed uniform formation of biofilm onto neat HDPE. The best performance in terms of reduced biofilm formation and biofouling onto HDPE floaters was achieved for E. coli (ZnO: 2 wt% and CB: 2 wt%), whereas for Pseudomonas aeruginosa (ZnO: 3 wt% and CB: 2 wt%). Application of greener polymers and nanoparticles for future studies is highly recommended. [ABSTRACT FROM AUTHOR]

This article explores the impact of plant growth regulators and nano zinc on the growth and yield of wheat. The study was conducted in Prayagraj, India and found that the application of Nano zinc 120 ppm + Salicylic acid 400 mg/l resulted in higher growth parameters and superior yield parameters. The study suggests that using plant growth regulators and nano zinc can enhance wheat growth and yield. The combination of Nano zinc and Salicylic acid was found to be particularly effective in improving plant dry weight, number of tillers per hill, and test weight. [Extracted from the article]

Background: Environment contamination with heavy metals is a major problem both to the environment and human health. Aims: The aim of this work is to evaluate the physiological, nutritional, and biochemical responses of safflower plants (Carthamus tinctorius L.) grown under different zinc concentrations at vegetative stage. Methods: The effect of zinc on safflower plants was studied through the evaluation of growth parameters, colorimetric assay of phenolic compounds, and antioxidant enzymes activities. Results: Zinc inhibited shoot and root growth and resulted in leaf chlorosis at 75, 225, and 1000 µM zinc concentrations. At higher concentrations, Zn also reduced photosynthetic parameters except the internal CO2 concentration that was higher at these levels. Zinc reduced potassium content of the shoots at 75 µM of zinc. The presence of Zn at 1000 µM concentration reduced the iron content and led to the accumulation of the copper content in the shoots. In roots, iron and copper contents were reduced from 15 µM Zn. In the case of copper, this content was canceled out at 225 and 1000 µM of zinc. Lipid peroxidation (evaluated as thiobarbituric acid reactive substances content) increased with zinc treatment. Safflower plants generally responded to this oxidative stress by enhancing the antioxidant enzymes activities, namely, catalase, ascorbate peroxidase, and guaiacol peroxidase. There was no increase in superoxide dismutase activity in shoots and roots, except at the highest zinc concentration in the roots. Total soluble sugars (TSS) and starch contents increased, whereas proline content decreased in shoots. In roots, TSS was not altered, whereas starch was decreased, and proline content was increased. There were no changes in the protein content in both organs under different Zn treatments. There was a gradual increase in the total polyphenols in shoots with increasing zinc concentration; however, no changes were observed in the roots. Flavonoids decreased in roots at 225 and 1000 µM Zn. Total antioxidant activity increased in shoots but it decreased in roots with increasing zinc concentration. The inverse trend was observed for the DPPH and ABTS tests. Conclusions: Our results suggest that the decline in safflower plant growth under high zinc concentrations is related to altered photosynthetic activity and antioxidant response to oxidative stress. [ABSTRACT FROM AUTHOR]

The article discusses a field experiment that examined the effects of phosphorus and foliar application of iron and zinc on the growth and yield of cowpea. The study found that a specific treatment involving phosphorus, iron, and zinc significantly increased the growth and yield of cowpea compared to other treatments. The research highlights the importance of these nutrients in enhancing the productivity of cowpea, a legume crop that can provide affordable protein. The addition of phosphorus, iron, and zinc promotes plant development and can improve the economic analysis of crop cultivation. However, further research is needed to confirm these findings. [Extracted from the article]

Abiotic stresses are among the major limiting factors for plant growth and crop productivity. Among these, salinity is one of the major risk factors for plant growth and development in arid to semi-arid regions. Cultivation of salt tolerant crop genotypes is one of the imperative approaches to meet the food demand for increasing population. The current experiment was carried out to access the performance of different rice genotypes under salinity stress and Zinc (Zn) sources. Four rice genotypes were grown in a pot experiment and were exposed to salinity stress (7 dS m-1), and Zn (15 mg kg-1 soil) was applied from two sources, ZnSO4 and Zn-EDTA. A control of both salinity and Zn was kept for comparison. Results showed that based on the biomass accumulation and K+/Na+ ratio, KSK-133 and BAS-198 emerged as salt tolerant and salt sensitive, respectively. Similarly, based on the Zn concentration, BAS-2000 was reported as Zn-in-efficient while IR-6 was a Zn-efficient genotype. Our results also revealed that plant growth, relative water content (RWC), physiological attributes including chlorophyll contents, ionic concentrations in straw and grains of all rice genotypes were decreased under salinity stress. However, salt tolerant and Zn-in-efficient rice genotypes showed significantly higher shoot K+ and Zn concentrations under saline conditions. Zinc application significantly alleviates the harmful effects of salinity by improving morpho-physiological attributes and enhancing antioxidant enzyme activities, and the uptake of K and Zn. The beneficial effect of Zn was more pronounced in salt-tolerant and Zn in-efficient rice genotypes as compared with salt-sensitive and Zn-efficient genotypes. In sum, our results confirmed that Zn application increased overall plant's performance under saline conditions, particularly in Zn in-efficient and tolerant genotypes as compared with salt-sensitive and Zn efficient rice genotypes. [ABSTRACT FROM AUTHOR]

Many authors who investigated the effect of Zn on seed germination, and growth and development of plants showed that zinc is reducing the seed germination rate, and inhibits the elongation of shoot and root in various plant species. The aim of this research was to investigate the effect of different concentrations of zinc on seed germination, stem and root growth as well as the increase of fresh and dried (dry) weight in corn. The substance used in the experiments for this type of plant was: Zinc sulfate (ZnSO4) and that in the following concentrations: 10-5, 10-4, 10-3, 10-2, 2 x 10-2, 4 x 10-2, 5 x 10-2, 6 x 10-2, 8 x 10-3 M. These concentrations have been used in tests in the form of aqueous solutions prepared with distilled water. The action of the substance during the experiment was permanent- permanent treatment (T.P.) and limited- before treatment (P. T.) for 24, 48 and 72. The seeds, before being placed in germination, are cleaned with ordinary water and then with distilled water two or three times. The seeds were germinated in a thermostat at a temperature of 26°C. The percentage of germinated seeds is determined after 96 hours from the moment they are placed for germination. The determination of the length of the plant organs was done 10 days after the placement of the seeds for germination. Their length is determined by measuring the main shoots and roots and is expressed as the average for a stalk, respectively root. Ten days after the seeds are set for germination, the increase of fresh and dry weight of corn is also determined, depending on the concentrations of ZnSO4. Based on the obtained results it can be noticed that zinc sulfate in lower concentrations (10-5, 10-4, 10-3 M) not only does not inhibit seed germination but in many cases stimulates seed germination, compared to high concentrations (10-2, 2 x 10-2, 4 x 10-2, 6 x 10-2, and 8 x 10-2 M). Zinc sulfate in small concentrations (10-5 to 2 x 10-2 M) did not inhibit further growth of previously germinated seeds. High concentrations (4 x 10-2 to 8 x 10-2 M) significantly inhibit further shoot and root growth in germinated seeds. Small concentrations of zinc sulfate stimulate stem and root growth. The greatest inhibitory effect of high concentrations occurs in root growth because the cell membrane walls are thinner. [ABSTRACT FROM AUTHOR]

Background: Soybean [Glycine max (L.) Merrill] is an annual herbaceous leguminous grain crop which is cultivated mainly for its oil and protein. The objective of the study was to determine the effects of plant density and zinc added to phosphorus fertilizer sources on soybean yield performance under different environmental conditions. Methods: A field trial was executed in two sites during the 2018/19 and 2019/20 summer planting seasons. The experimental design involved a 2 × 2 × 5 factorial fitted into a randomized complete block design (RCBD) with four replications. The experiment consisted of two plant densities, a lower plant density of 66 666 plants/ha and a higher plant density of 111 111 plants/ha. The five different types of fertilizer treatments were single superphosphate, monoammonium phosphate, zinc sulphate added to single superphosphate, zinc sulphate added to monoammonium phosphate and control. Result: The results showed that plant density has a significant effect (P<0.05) on soybean number of pods per plant and the field biomass yield. Soybean planted under lower plant density conditions produced a significantly larger number of pods per plant during both planting seasons, whereas higher plant density conditions resulted in a higher soybean field biomass yield during the 2018/19 planting season. It was observed that soybean treated with monoammonium phosphate had higher seed mass. [ABSTRACT FROM AUTHOR]

Zinc is an important microelement that enters into the composition of hundreds of enzymes and thousands of proteins in the plant and animal world. The aim of the study was to analyze the effect of foliar application of zinc in acid soil on the most important seed yield components and seed yield of selected red clover (Trifolium pratense L.) genotypes from Serbia and Bulgaria. The experiment was established in 2012 in Čačak (Serbia) on loessivized vertisol soil type with acid reaction (pHH2O 4.8). Sowing was done at a distance of 70x40 cm. There were used four different genotypes of red clover, three of which were isolated from the local population and variety of K-39. For the analysis was used the second cut in the second year of cultivation. Two treatments were used: control - no fertilization and foliar treatment with zinc in the form of ZnSO4 x 7H2O, at a concentration of 0.2%, using 1000 L ha-1 of water, at the stage of intensive plant growth. Foliar application of zinc had a positive effect on the number of stems per plant, the number of inflorescences per stem, the number of inflorescences per plant and the number of flowers per inflorescence. The negative effect of foliar application of zinc has been reported on the thousand seeds weight and the fertility of flowers at the genotypes originating from Bulgaria. A significant increase in seed yield per plant, under the influence of foliar application of zinc, was observed only in the variety K-39 (for 11.4 g plant-1), which otherwise had the highest seed yield. [ABSTRACT FROM AUTHOR]

Background: Non-destructive high-throughput plant phenotyping is becoming increasingly used and various methods for growth analysis have been proposed. Traditional longitudinal or repeated measures analyses that model growth using statistical models are common. However, often the variation in the data is inappropriately modelled, in part because the required models are complicated and difficult to fit. We provide a novel, computationally efficient technique that is based on smoothing and extraction of traits (SET), which we compare with the alternative traditional longitudinal analysis methods. Results: The SET-based and longitudinal analyses were applied to a tomato experiment to investigate the effects on plant growth of zinc (Zn) addition and growing plants in soil inoculated with arbuscular mycorrhizal fungi (AMF). Conclusions from the SET-based and longitudinal analyses are similar, although the former analysis results in more significant differences. They showed that added Zn had little effect on plants grown in inoculated soils, but that growth depended on the amount of added Zn for plants grown in uninoculated soils. The longitudinal analysis of the unsmoothed data fitted a mixed model that involved both fixed and random regression modelling with splines, as well as allowing for unequal variances and autocorrelation between time points. Conclusions: A SET-based analysis can be used in any situation in which a traditional longitudinal analysis might be applied, especially when there are many observed time points. Two reasons for deploying the SET-based method are (i) biologically relevant growth parameters are required that parsimoniously describe growth, usually focussing on a small number of intervals, and/or (ii) a computationally efficient method is required for which a valid analysis is easier to achieve, while still capturing the essential features of the exhibited growth dynamics. Also discussed are the statistical models that need to be considered for traditional longitudinal analyses and it is demonstrated that the oft-omitted unequal variances and autocorrelation may be required for a valid longitudinal analysis. With respect to the separate issue of the subjective choice of mathematical growth functions or splines to characterize growth, it is recommended that, for both SET-based and longitudinal analyses, an evidence-based procedure is adopted. [ABSTRACT FROM AUTHOR]

Zinc deficiency is among the top five micronutrient deficiencies and severely affects one-third of world's population, especially rural communities. Micronutrient malnutrition is a global health problem affecting more than 3 billion people world-wide. Among the various micronutrient deficiency, Zn is the most prevalent. About 44 % of children under five years of age are Zn-deficient in India. As one of the most common cereal crops, wheat contributes to the provision of daily calories, proteins and bioavailable micronutrients. Wheat is inherently very low in the bioavailability of Zn, Fe, Mn and Cu. Under severely Zn-deficient soils, Zn concentration of wheat grains may be as low as 10 mg/kg, whereas the human requirement is 40-60 mg/kg and the world current situation is 10-30 mg/kg. In many developing nations wheat provides over 50% of the daily intake of calories. Inadequate intake of foods low in Zn content is a major contributor to the prevalence of Zn deficiency in humans. The effects of Zn deficiency on human health are significant and lead to reduced growth and immunity, learning deficits, mental retardation and DNA damage. Different reports are available indicating that more than 50% of wheat around the globe is cultivated on Zn-deficient soils, which further lower grain Zn content. In response to the aforementioned problem, different approaches have been suggested in developing nations in which the biofortification of cereals with important micronutrient is receiving a great deal of attention. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of foliar application of zinc and manganese at different stage of potato growth on some quality characteristics of potato tuber (Solanum tuberosum L.) class (Desiree) fertilized with organic matterin silt clay loam texture soil in one of the agricultural fields in Deptartment of Horticulture, Faculty of Agricultural Engineering Sciences, University of Baghdad for the spring season 2012. A randomized complete block design RCBD was used with three replicates including two factors the first factor is foliar application includes the treatment (T0 water spray only, T1 spraying with zinc at 60 mg l-1, T2 spraying with manganese at 30 mg L-1 and T3 spraying with zinc at 60 mg L-1 + Spraying with manganese at 30 mg L-1) and the second factor is the stage of potato growth includes the treatments (F1 spraying in the vegetative growth, F2 spraying in tuber initiation and F3 spraying at tuber bulking). Addition of organic manure (mixture of equal amounts of cows, sheep and chicken) at 50 tons.ha-1 for all treatments at 10 days before planting. The results showed the significant effect of zinc and manganese spraying at different stage and their interactions, the treatment T3F1 has recorded the highest dry matter for tubers at 16.17% with an increase of 24.57% compared to the treatment T0F1 and recorded the highest Starch percentage at 10.40% with an increase of 42.08% compared to the treatment T0F2. [ABSTRACT FROM AUTHOR]

The study was conducted in the non-heated plastic house belonging to Department of Horticulture and Landscaper gardening, Collage of Agriculture and Forestry, University of Mosul, Iraq for the period from January 2013 to August 2013 on Gladiolus hybrida plants (Traderhorn cultivar). The corms were soaked with Gibberellic acid (GA3) at a concentration of (100 mg.L-1) for 24 hours or soaking with paclobutrazol at concentration of (50 mg.L-1), for 10 min before cultivating, the plants were sprayed with Boric acid (17% Boron) at two concentrations of (0, 30 mg.L-1), with the chelated zinc of (11% zinc) at three concentrates of (0, 30, 60 mg.L-1). The spraying process was conducted in two batches when the second leaf appears and at the beginning of the emergence of flower stalk. A factorial experiment was used in the conducting the research according to Complete Randomized Blocks Design with the split plot system. The results showed that the spraying with boron or zinc or soaking with Gibberellic acid had a significant effect on increasing the length of flower stalk, number of florets, vase life, diameter of corms, number of cormels, Concentration of chlorophyll in leaves, The concentration of zinc at the concentration of (60 mg.L- 1) was significantly excelled on the concentration of (30 mg.L-1) for all studied traits, as for the soaking with paclobutrazol gave a significant increase in the number of florets, vase life, diameter of corms, number of cormels, Concentration of chlorophyll in leaves, which led to significant reduction in the length of flower stalk, A significant increase in most of the studied traits was observed in the bi-interactions. There were significant differences in most of the studied traits in the triple interaction when spraying with boron at a concentration of (30 mg.L-1) with spraying at a concentration of (60 mg.L-1) zinc mixed with Gibberellic acid or paclobutrazol, The number of cormels increased with percentage amounted of (143.13%) when paclobutrazol was mixed with both boron and zinc at a concentration of (60 mg.L-1). [ABSTRACT FROM AUTHOR]

A field experiment was carried out in the fields of the Faculty of Agriculture, University of Baghdad, in a soil mixed with green clay, classified under the group TypicTorrifluvents, to study the effect of paper feeding in iron and zinc in grains and leaves in wheat grains 99, 29 and 7. The experiment was carried out using the whole randomized sections and three replicates (0, 50 and 100 mg) Fe-1, (0, 50 and 100) Zn-1mg in the stages of plant growth and interference was sprayed in the same proportions. The results showed that all iron and zinc concentrations and their interactions significantly increased all study parameters. However, the Zn2Fe2 interaction coefficients achieved the highest values with a value of 190.50 mg.kg-1. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of foliar applications of potassium and zinc on the fruit yield and quality as well as leaf nutrient concentrations of pistachio cv. 'Chrokeh'. The experiment was conducted based on a completely randomized block design with nine treatments and three replications per treatment. Treatments were three levels of K2SO4 (0, 1 and 2%) and three levels of ZnSO4 (0, 0.5 and 1%). The nutrition solutions were sprayed on trees at two times (bud swell stage and green tip stage) in 2017-2018. Based on the obtained results, nutrient treatments especially 1% K2SO4+1% ZnSO4 and 2% K2SO4+1% ZnSO4 caused a significant increase in chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents. Application of K2SO4 and ZnSO4 significantly affected concentrations of P, K, Mg, Zn, Mn and Fe in the leaves of 'Chrokeh' pistachio, whereas nutrient treatments had no significant effect on leaf concentration of N. Nutrient treatments especially 2% K2SO4+1% ZnSO4 led to significant increases in the fresh (up to 65%) and dry (up to 67%) yield when compared with the control trees. Moreover, nutrient applications had a significant effect on the percentage of splitting (an 11 % increase) and blankness (a 26% decrease). It can be concluded that foliar application of K and Zn fertilizers is necessary for obtaining better fruit yield and quality in pistachio. [ABSTRACT FROM AUTHOR]

Abstract Aquaporins are water channel proteins that regulate plant development, growth, and response to environmental stresses. Populus trichocarpa is one of the plants with the highest number of aquaporins in its genome, but only few of them have been characterized at the whole plant functional level. Here we analyzed a putative aquaporin gene, aqua1 , a gene that encodes for a protein of 257 amino acid with the typical NPA (Asp-Pro-Ala) signature motif of the aquaporin gene family. aqua1 was down-regulated of ∼10 fold under excess Zn in both leaves and roots, and conferred Zn tolerance when expressed in yeast Zn hypersensitive strain. In vivo localization of AQUA1-GFP in Arabidopsis protoplast showed a heterogeneous distribution of this protein on different membranes destined to form aggregates related to autophagic multivesicular bodies. Zn-dependent AQUA1-GFP re-localization was perturbed by phosphatases' and kinases' inhibitors that could affect both intracellular trafficking and aquaporins' activity. Exposed to high concentration of Zn, AQUA1 also co-localized with AtTIP1;1, a well-known Arabidopsis vacuolar marker, probably in pro-vacuolar multivesicular bodies. These findings suggest that high concentration of Zn down-regulates aqua1 and causes its re-localization in new forming pro-vacuoles. This Zn-dependent re-localization appears to be mediated by mechanisms regulating intracellular trafficking and aquaporins' post-translational modifications. This functional characterization of a poplar aquaporin in response to excess Zn will be a useful reference for understanding aquaporins' roles and regulation in response to high concentration of Zn in poplar. Highlights • AQUA1 is a Hg-sensitive aquaporin. • aqua1 is regulated at transcriptional levels in response to Zn excess. • Excess Zn causes the relocalization of aqua1 in newly forming compartments. • aqua1 sub-cellular localization is regulated by post-translational modification. [ABSTRACT FROM AUTHOR]

Abstract Zinc (Zn) possesses similar properties to cadmium (Cd) and inhibits Cd uptake in plants. To get more detailed mechanisms of Zn-inhibited Cd uptake in pakchoi, a hydroponic experiment was conducted to investigate the effects of various Zn levels on Cd concentrations, real time flux of Cd, expressions of genes related to Cd uptake under Cd exposure. The results showed that the Cd concentrations and Cd accumulations in pakchoi root decreased with increasing Zn levels, which were coincident with that real time Cd influx and net Cd influx of pakchoi root decreased with increasing Zn levels by non-invasive micro-test technology (NMT). Additionally, the expressions of Cd-related transporters including BcNRAMP5 , BcIRT1 and BcMGT1 decreased with the increase of Zn levels under Cd exposure, especially BcIRT1 with the highest decreased rates. Furthermore, the expressions of these genes decreased gradually with the prolongation of Zn treated time under Cd toxicity. The results indicate that Zn inhibits Cd uptake by inhibition of the expressions of Cd-related transporters, especially BcIRT1 in pakchoi root. Highlights • NMT showed that Zn inhibited net Cd2+ influx in root. • Zn reduced Cd uptake by inhibiting expressions of Cd transporter in root. • Zn-reduced Cd uptake was involved in Zn-alleviated Cd toxicity in shoot. [ABSTRACT FROM AUTHOR]

More than a billion people suffer from iron or zinc deficiencies globally. Rice (Oryza sativa L.) iron and zinc biofortification; i.e., intrinsic iron and zinc enrichment of rice grains, is considered the most effective way to tackle these deficiencies. However, rice iron biofortification, by means of conventional breeding, proves difficult due to lack of sufficient genetic variation. Meanwhile, genetic engineering has led to a significant increase in the iron concentration along with zinc concentration in rice grains. The design of impactful genetic engineering biofortification strategies relies upon vast scientific knowledge of precise functions of different genes involved in iron and zinc uptake, translocation and storage. In this review, we present an overview of molecular processes controlling iron and zinc homeostasis in rice. Further, the genetic engineering approaches adopted so far to increase the iron and zinc concentrations in polished rice grains are discussed in detail, highlighting the limitations and/or success of individual strategies. Recent insight suggests that a few genetic engineering strategies are commonly utilized for elevating iron and zinc concentrations in different genetic backgrounds, and thus, it is of great importance to accumulate scientific evidence for diverse genetic engineering strategies to expand the pool of options for biofortifying farmer‐preferred cultivars. Human iron and zinc deficiencies are serious global health concerns. Iron and zinc homeostasis is tightly regulated in plants. By modulating mechanisms underlying iron and zinc uptake, translocation and storage, various biotechnological strategies succeeded in enhancing the iron and zinc concentrations in rice grains. [ABSTRACT FROM AUTHOR]

Human activities generate environmental stresses that can lead plant populations to become extinct. Population survival would require the evolution of adaptive responses that increase tolerance to these stresses. Thus, in pseudometallophyte species that have colonized anthropogenic metalliferous habitats, the evolution of increased metal tolerance is expected in metallicolous populations. However, the mechanisms by which metal tolerance evolves remain unclear. In this study, parent populations were created from non-metallicolous families of Noccaea caerulescens. They were cultivated for one generation in mesocosms and under various levels of zinc (Zn) contamination to assess whether Zn in soil represents a selective pressure. Individual plant fitness estimates were used to create descendant populations, which were cultivated in controlled conditions with moderate Zn contamination to test for adaptive evolution in functional traits. The number of families showing high fitness estimates in mesocosms was progressively reduced with increasing Zn levels in soil, suggesting increasing selection for metal tolerance. In the next generation, adaptive evolution was suggested for some physiological and ecological traits in descendants of the most exposed populations, together with a significant decrease of Zn hyperaccumulation. Our results confirm experimentally that Zn alone can be a significant evolutionary pressure promoting adaptive divergence among populations. [ABSTRACT FROM AUTHOR]

Enzymatic browning (EB) in apple occurred during processing or fresh consumption as fresh cut. EB in response to pre-harvest Zn spray at two apple cultivars was investigated. Trees of apple ( Malus domestica cultivar ‘Delbard Estival’ and ‘Kohanz’) were sprayed with water (control), 0.13% of Chelated Zn (C-Zn) or 0.13% of Nano-Chelated Zn (NC-Zn) three or four weeks before harvest. Assessments were carried at spray time, three or four weeks (H1 and H2) after spray and also after 3 weeks of storage (H1 + 3 W and H2 + 3 W) at 4 °C with 95% (RH). The browning index (BI) and total color changes (ΔE) decreased from spray time until harvest time. BI and ΔE in treated fruit were lower than control at all time points except in H1. Starch index was delayed in fruit treated with C-Zn or NC-Zn. The highest firmness of ‘Delbard Estival’ and ‘Kohanz’ cultivars was observed in NC-Zn than other treatments at all sampling times. Titratable acidity, soluble solids content and total phenol showed no distinct changes during time. The ascorbic acid, total antioxidant activity and superoxide dismutase in C-Zn or NC-Zn treatments were higher than control in both cultivars except superoxide dismutase activity at H1 for NC-Zn. The polyphenol oxidase activity in both cultivars treated with C-Zn or NC-Zn was lower than control at all sampling time except at H1 in ‘Kohanz’ cultivar. These findings suggest that the pre-harvest spray with Zn and especially NC-Zn can improve flesh color changes and quality parameters in apples. [ABSTRACT FROM AUTHOR]

Suitable germplasm and breeding for zinc (Zn)-efficient genotypes has been prioritized to combat Zn deficiency problem. Six maize genotypes were grown in a nutrient solution with or without Zn to identify genotype tolerance to low Zn and its mechanism. Zhongnong 99 was found to be about 2-fold more Zn-efficient than L69 × 178. Young shoot Zn concentration and content was significantly correlated with Zn efficiency (ZE). Furthermore, Zn-efficient genotype as Zhongnong 99 distributed more Zn into young parts of shoot and also developed longer and thinner roots (≤ 0.2 mm) under -Zn conditions than inefficient genotypes. The close relationship (0.82***, 0.88***, 0.90***) between Zn content of young shoots and fine roots indicated that fine roots (≤ 0.2 mm) contributed more efficient Zn uptake into old parts which distributed to young parts. In conclusion, the analysis of young shoots and fine roots (≤ 0.2 mm) represent a suitable screening technique for ZE evaluation of under -Zn conditions. [ABSTRACT FROM AUTHOR]

The time, quantity and method of nutrients application are crucial factors for enhanced crop yield and economic return. This study investigated the effect of phosphorous (0, 35, 70 and 105 kg P2O5 ha-1) and zinc (0, 10, 20 and 30 kg ha-1) levels applied through broadcast and banding on chickpea growth and yield during winter 2013-14 at the New Developmental Farm, The University of Agriculture, Peshawar. The experiment was carried out by following randomized complete block design procedure replicated four times. Pods number plant-1 (PN), grain yield (GY) biological yield (BY), and harvest index (HI) were significantly increased by 9, 4, 23 and 8%, respectively over the control with fertilizer banding compared with broadcast. Plots receiving 10 kg Zn ha-1 registered a significant increase of 8, 9, 4, 27 and 9%, in plant height (PH), PN, GY, BY and HI, respectively over the control, and recorded the lowest number of days to maturity (185) compared to control (188 days). Both 70 and 105 kg P2O5 ha-1 registered PH with 8% increase, PN with 8 and 7.4% increase, respectively, GY with 4% increase, BY with 25% increase and HI with 9.2 and 9.5% increase over the control. Number of days to achieve crop maturity also remained the same (185 days) for the P2O5 levels and remained statistically similar with each other (185 days) compared to the control (188 days). Interaction of 70 kg P2O5 with 10 kg Zn ha-1 produced maximum HI (35%). This study suggested that 70 kg P2O5 ha-1 and 10 kg Zn ha-1 should be applied in bands for enhanced yield and related growth traits of the chickpea crop. Interaction among nutrients and application methods showed that application of nutrients with band placement method gave excellent results even at lower doses emphasizing proper application method as more important than mare increasing nutrient levels for obtaining higher returns. [ABSTRACT FROM AUTHOR]

Key message: Twelve meta-QTL for seed Fe and Zn concentration and/or content were identified from 87 QTL originating from seven population grown in sixteen field trials. These meta-QTL include 2 specific to iron, 2 specific to zinc and 8 that co-localize for iron and zinc concentrations and/or content.Abstract: Common bean (Phaseolus vulgaris L.) is the most important legume for human consumption worldwide and it is an important source of microelements, especially iron and zinc. Bean biofortification breeding programs develop new varieties with high levels of Fe and Zn targeted for countries with human micronutrient deficiencies. Biofortification efforts thus far have relied on phenotypic selection of raw seed mineral concentrations in advanced generations. While numerous quantitative trait loci (QTL) studies have been conducted to identify genomic regions associated with increased Fe and Zn concentration in seeds, these results have yet to be employed for marker-assisted breeding. The objective of this study was to conduct a meta-analysis from seven QTL studies in Andean and Middle American intra- and inter-gene pool populations to identify the regions in the genome that control the Fe and Zn levels in seeds. Two meta-QTL specific to Fe and two meta-QTL specific to Zn were identified. Additionally, eight Meta QTL that co-localized for Fe and Zn concentration and/or content were identified across seven chromosomes. The Fe and Zn shared meta-QTL could be useful candidates for marker-assisted breeding to simultaneously increase seed Fe and Zn. The physical positions for 12 individual meta-QTL were identified and within five of the meta-QTL, candidate genes were identified from six gene families that have been associated with transport of iron and zinc in plants. [ABSTRACT FROM AUTHOR]

Adequate supply of micronutrients is important for the proper growth and yield of lentil, particularly in poorly fertile soil. This study was carried out to understand the effects of zinc (Zn), boron (B), and molybdenum (Mo) on the growth and yield of lentil, and how these elements can help manage soil fertility issues. In this regard, the morpho-physiological traits of lentils (BARI Masur-7) were collected from two experiments receiving the same treatments carried out during consecutive rabi seasons of 2015-2016 and 2016-2017. The experiments were laid out with a randomized complete block design having eight treatments, and was replicated thrice. The treatments were T1 (Control), T2 (Zn2.0 kg ha-1), T5 (Zn2.0B1.5 kg ha-1), T6 (Zn2.0Mo1.0 kg haha-1), T7 (B1.5Mo1.0 kg ha-1), and T8 (Zn2.0B1.5Mo1.0 kg ha-1). The results revealed that the application of micronutrients either singly or in combination had significant effects on the plant height, number of branches per plant, number of pods per plant, number of seeds per pod, thousand seed weight, and the seed yield of lentil. The maximum seed production was, however, observed in plots receiving treatment T8, i.e., the combined application of Zn, B, and Mo. Agronomic biofortification also had significantly increased protein content of lentil seeds while affecting the macro and micronutrient content of lentil seed. These results suggest that any micronutrient deficiencies might lead to a yield loss of lentil, and such a scenario could be avoided by a combined application of micronutrients at a proportionate level. [ABSTRACT FROM AUTHOR]

This present paper studies the response of Anthyllis vulneraria-Rhizobium symbiosis to heavy metal stress. The symbiotic rhizobium bacteria isolated from root nodules of A. vulneraria from zinc and lead wastes were examined in this project. Light microscopy (LM) and transmission electron microscopy (TEM) were used to analyze the nodule anatomy and ultrastructure and conduct a comparison with nonmetal-treated nodules. 16S ribosomal DNA sequence analysis of bacteria isolated from metal-treated nodules revealed the presence of Rhizobium metallidurans and Bradyrhizobium sp. In regard to heavy metal resistance/tolerance, a similar tolerance to Pb was shown by both strains, and a high tolerance to Zn and a lower tolerance to Cd and Cu by R. metallidurans, whereas a high tolerance to Cd and Cu and a lower tolerance to Zn by Bradyrhizobium were found. The nodules of Anthyllis from metal-polluted tailing sites were identified as the typical determinate type of nodules. Observed under TEM microscopy changes in nodules ultrastructure like: (1) wall thickening; (2) infection thread reduction; (3) vacuole shrinkage; (4) synthesis of phenolics in vacuoles; (5) various differentiation of bacteroids and (6) simultaneous symbiosis with arbuscular mycorrhiza fungi could be considered as a form of the A.vulneraria-Rhizobium symbiosis adaptation to metal stress. [ABSTRACT FROM AUTHOR]

Iron (Fe) and zinc (Zn) are essential micronutrients required for proper development in both humans and plants. Rice (Oryza sativa L.) grains are the staple food for nearly half of the world’s population, but a poor source of metals such as Fe and Zn. Populations that rely on milled cereals are especially prone to Fe and Zn deficiencies, the most prevalent nutritional deficiencies in humans. Biofortification is a cost-effective solution for improvement of the nutritional quality of crops. However, a better understanding of the mechanisms underlying grain accumulation of mineral nutrients is required before this approach can achieve its full potential. Characterization of gene function is more time-consuming in crops than in model species such as Arabidopsis thaliana. Aiming to more quickly characterize rice genes related to metal homeostasis, we applied the concept of high throughput elemental profiling (ionomics) to Arabidopsis lines heterologously expressing rice cDNAs driven by the 35S promoter, named FOX (Full Length Over-eXpressor) lines. We screened lines expressing candidate genes that could be used in the development of biofortified grain. Among the most promising candidates, we identified two lines ovexpressing the metal cation transporter OsZIP7. OsZIP7 expression in Arabidopsis resulted in a 25% increase in shoot Zn concentrations compared to non-transformed plants. We further characterized OsZIP7 and showed that it is localized to the plasma membrane and is able to complement Zn transport defective (but not Fe defective) yeast mutants. Interestingly, we showed that OsZIP7 does not transport Cd, which is commonly transported by ZIP proteins. Importantly, OsZIP7-expressing lines have increased Zn concentrations in their seeds. Our results indicate that OsZIP7 is a good candidate for developing Zn biofortified rice. Moreover, we showed the use of heterologous expression of genes from crops in A. thaliana as a fast method for characterization of crop genes related to the ionome and potentially useful in biofortification strategies. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency remarkably depresses the protein concentration in the grain of winter wheat. Cultivar ‘Pingan 8’ showed lower Zn concentrations in the grain than did cultivar ‘Yangao 006’ after nitrogen (N) combined with Zn application. However, little is known about how amino acids are influenced by Zn combined with N application or about the differences in amino acid accumulation between the two winter wheat cultivars. A pot experiment was conducted to characterize amino acid accumulation in the low Zn-accumulating cultivar ‘Pingan 8’ and the high Zn-accumulating cultivar ‘Yangao 006’ at various growth stages (seedling, jointing, grain filling and maturity) as influenced by N and Zn supply. The N (N 0.2 ) combined with Zn (Zn 10 ) application significantly increased grain yields and the concentrations of N, Zn and crude protein in the grain of both wheat cultivars. N combined with Zn application significantly increased the concentrations of glutamate (Glu) and asparagine (Asn) but decreased the concentrations of glutamine (Gln) and aspartate (Asp) in cultivar ‘Yangao 006’; the N combined with Zn application decreased the concentrations of Glu and Gln but increased the concentrations of Asp and Asn in cultivar ‘Pingan 8’ at the jointing, grain filling and mature stages. Correlation analysis results showed that there were significant relationships between grain yields, spike number, grain number and Zn, N, crude protein, Glu, Gln, Asp and Asn concentrations in the shoots and grain of winter wheat at different growth stages. These results demonstrate that N combined with Zn application enhanced protein synthesis by altering amino acid accumulation in both winter wheat cultivars. Cultivar ‘Pingan 8’ had lower Gln, Asp and Asn concentrations and higher Glu concentrations than did cultivar ‘Yangao 006’ after the N 0.05 treatment but had higher Glu, Gln, Asp, and Asn concentrations and lower Glu concentrations than did cultivar ‘Yangao 006’ after the N 0.2 treatment. These results revealed that the difference in amino acid concentrations between the two cultivars was related to the N application level. [ABSTRACT FROM AUTHOR]

Summary: Rhizobium leguminosarum bv. trifolii is a soil bacterium that establishes symbiosis with clover (Trifolium spp.) under nitrogen‐limited conditions. This microorganism produces exopolysaccharide (EPS), which plays an important role in symbiotic interactions with the host plant. The aim of the current study was to establish the role of EPS in the response of R. leguminosarum bv. trifolii cells, free‐living and during symbiosis, to zinc stress. We show that EPS‐deficient mutants were more sensitive to Zn2+ exposure than EPS‐producing strains, and that EPS overexpression conferred some protection onto the strains beyond that observed in the wild type. Exposure of the bacteria to Zn2+ ions stimulated EPS and biofilm production, and increased cell hydrophobicity. However, zinc stress negatively affected the motility and attachment of bacteria to clover roots, as well as the symbiosis with the host plant. In the presence of Zn2+ ions, cell viability, root attachment, biofilm formation and symbiotic efficiency of EPS‐overproducing strains were significantly higher than those of the EPS‐deficient mutants. We conclude that EPS plays an important role in the adaptation of rhizobia to zinc stress, in both the free‐living stage and during symbiosis. [ABSTRACT FROM AUTHOR]

Zinc (Zn) deficiency is one of the main micronutrient disorders in rice and it may inflict its deficiency in the people feeding on it. Selection of rice genotypes with higher potential of Zn uptake is considered as natural and better way to combat malnutrition. Present study evaluated the potential of foliar and soil applied Zn in improving the performance of paddy rice and Zn bioavailability. In glass house, different sources of zinc (ZnSO4.7H2O and ZnCl2) and rate treatments for soil (control, 5 kg ha-1, 10 kg ha-1, 15 kg ha-1 and 20 kg ha-1 of Zn) and foliar application (control, 0.25%, 0.5%, 0.75% and 1% solution) were used. Selected rate and source treatments were appraised in field experiments. The rice grains harvested thereof were fed to albino rats for Zn bioavailability. Results revealed that soil application with 15 kg ha-1 and foliar application of 0.25% solution using ZnSO4.7H2O improved the early seedling growth of rice genotypes by modulating the agronomic, water related and biochemical attributes. Field experiments confirmed that Zn application through soil and foliar spray improved the performance of rice genotypes by improving growth attributes, chlorophyll pigments, and yield and resulted in Zn enrichment of rice grains in various genotypes. The maximum weekly body weight gain and white blood cells count of albino rats was observed for feeding the kernels of Accession-164 (high Zn) as compared with the minimum for Super Basmati (low Zn) feed. In crux, soil application of ZnSO4 at 15 kg ha-1 followed by foliar application of 0.25% ZnSO4 solution at tillering and heading stage not only recorded the highest growth and grain yield, but also showed maximum bioavailable Zn in the grains. Such rice grains with high Zn concentrations were also effective for combating malnutrition in the tested rats. [ABSTRACT FROM AUTHOR]

Jatropha curcas seedlings were cultured for 21 d under 6 zinc concentrations of 0, 25, 50, 100, 200, 400mg/l to study the effects of ZnS04 stress on the mechanism of resistance to heavy metal stress of J. curcas seedlings. The results showed that with the increase of stress concentration, the content of chlorophyll-a decreased and the activity of POD first increased and then maintained at a certain level or decreased slowly. The contents of soluble sugar, malondialdehyde, soluble protein and free proline increased, and the root activity increased first and then decreased. The relative conductivity of J. curcas seedlings decreased first and then increased, which indicated that the leaves of J. curcas seedlings had some adaptability and self-repairing capability under zinc toxicity stress, but the adaptability and self-repair ability were limited. [ABSTRACT FROM AUTHOR]

Twenty-five field experiments were conducted on rice (Oryza sativa) as test crop across Uttar Pradesh, Punjab, Haryana and Himachal Pradesh during the two consecutive kharif seasons of 2015 and 2016. The effects of soil and foliar fertigation of zinc (Zn) on rice grain yield and grain Zn concentration were studied. Farmer's field under three different Zn application methods was designed with complete randomized block design in three replicates, as following treatments : (i) Farmers' practices without Zn application or business as usual (control), (ii) Farmers' practices with 50 kg ZnSO4.7H2O/ha soil Zn application before transplanting of rice crop and (iii) Farmers' practices with foliar Zn application (0.5% (w/v) aqueous solution of ZnSO4.7H2O was realized two times (i. e. first at anthesis or heading and the second one at early milking stage of rice crop). Both Zn application methods increased rice grain yield across 25 sites. However, the effect of soil Zn fertilizer on grain yield was more effective than foliar Zn. Foliar Zn treatments on rice increased grain Zn concentration significantly over control across all locations. In particular rice crop, soil Zn application noticeably increased grain yield and slightly less content of grain Zn over foliar Zn application. However, foliar application of Zn at particular growth stages of rice was an important agronomic practice for the farmers to enhance grain yield and Zn concentration to alleviate 'hidden hunger'. In conclusion, soil Zn application method increased rice yield and profitability as compared to farmers' practices (control). Given the high effectiveness of foliar Zn application in increasing grain Zn concentration, it is recommended that farmers apply Zn to rice by foliar application for both grain yield and optimum grain Zn biofortification to combat Zn deficiency. [ABSTRACT FROM AUTHOR]

The effect of excess Zn and arbuscular mycorrhizal (AM) fungus on bioproduction and trace element nutrition were investigated in tomato. In a completely randomized factorial design, the experimental treatments - Zn addition at 0 (normal) and 300 (excess) mg Zn kg−1 soil, and AM inoculation (non-AM and Rhizophagus irregularis) - were set up in a growth chamber for 10 weeks. Generally, AM effects on the available Zn, Mn, Cu, and Fe in the rhizosphere soil were in tandem with the effects in host tissues. Under normal Zn condition, AM enhanced Cu availability in the rhizosphere, optimized the Cu:Zn balance in shoots, and increased the host biomass production. Excess Zn reduced mycorrhizal colonization in AM plants and the total plant biomass in both AM and non-AM plants. Although AM decreased the Zn concentrations in soil and host tissues under excess Zn, the distortions in host TE balance were not significantly ameliorated by the fungus. While Zn in fruit was within the safety threshold, Mn deficiency in the fruit was observed under excess Zn, alongside increased root-to-fruit Fe and Cu translocations. Mycorrhizal reductions in soil and tissue Mn concentrations were considered a minus in terms of probable symbiont amelioration of Mn:Zn in-balance under excess Zn. Additional microbe(s) that can enhance Mn homeostasis might be helpful in tomato under elevated soil Zn. [ABSTRACT FROM AUTHOR]

Iron deficiency affects one third of the world population. Most iron biofortification strategies have focused on genes involved in iron uptake and storage but facilitating internal long-distance iron translocation has been understudied for increasing grain iron concentrations. Citrate is a primary iron chelator, and the transporter FERRIC REDUCTASE DEFECTIVE 3 (FRD3) loads citrate into the xylem. We have expressed AtFRD3 in combination with AtNAS1 ( NICOTIANAMINE SYNTHASE 1 ) and PvFER ( FERRITIN ) or with PvFER alone to facilitate long-distance iron transport together with efficient iron uptake and storage in the rice endosperm. The citrate and iron concentrations in the xylem sap of transgenic plants increased two-fold compared to control plants. Iron and zinc levels increased significantly in polished and unpolished rice grains to more than 70% of the recommended estimated average requirement (EAR) for iron and 140% of the recommended EAR for zinc in polished rice grains. Furthermore, the transformed lines showed normal phenotypic growth, were tolerant to iron deficiency and aluminum toxicity, and had grain cadmium levels similar to control plants. Together, our results demonstrate that deploying FRD for iron biofortification has no obvious anti-nutritive effects and should be considered as an effective strategy for reducing human iron deficiency anemia. [ABSTRACT FROM AUTHOR]

To investigate the effect of oxalic and citric acids on the uptake and relationship of phosphorus and zinc in corn (Zea mays L.), some greenhouse experiments were performed by individual and combined application of monopotassium phosphate [KH232PO4] and zinc sulfate [65ZnSO4.7H2O] fertilizers in microcosm. For this purpose after planting corn seeds, solutions of phosphorus (32P) and zinc (65Zn) (14 and 2 M) and organic acids treatments (1 and 10 mM) were injected in microcosms at suitable times. Then, plants were harvested, digested, extracted, and activity of 32P and 65Zn was measured in samples. Results revealed that the highest uptake of 32P in shoots was 18.8% and observed at 10 mM concentration of oxalic acid. But no effect on 65Zn uptake was seen and the highest uptake was observed in control (1.27%). The highest uptake of 32P and 65Zn in plant shoots and roots was observed at 10 mM concentration of oxalic and citric acids, respectively. [ABSTRACT FROM AUTHOR]

Zinc is an essential micronutrient for all living organisms and is involved in a plethora of processes including growth and development, and immunity. However, it is unknown if there is a common genetic and molecular basis underlying multiple facets of zinc function. Here we used natural variation in Arabidopsis thaliana to study the role of zinc in regulating growth. We identify allelic variation of the systemic immunity gene AZI1 as a key for determining root growth responses to low zinc conditions. We further demonstrate that this gene is important for modulating primary root length depending on the zinc and defence status. Finally, we show that the interaction of the immunity signal azelaic acid and zinc level to regulate root growth is conserved in rice. This work demonstrates that there is a common genetic and molecular basis for multiple zinc dependent processes and that nutrient cues can determine the balance of plant growth and immune responses in plants. [ABSTRACT FROM AUTHOR]

Summary: Zinc (Zn) hyperaccumulation and hypertolerance are highly variable traits in Arabidopsis halleri. Metallicolous populations have evolved from nearby nonmetallicolous populations in multiple independent adaptation events. To determine whether these events resulted in similar or divergent adaptive strategies to high soil Zn concentrations, we compared two A. halleri metallicolous populations from distant genetic units in Europe (Poland (PL22) and Italy (I16)). The ionomic (Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP‐AES)) and transcriptomic (RNA sequencing (RNA‐Seq)) responses to growth at 5 and 150 μM Zn were analyzed in root and shoot tissues to examine the contribution of the geographic origin and treatment to variation among populations. These analyses were enabled by the generation of a reference A. halleri transcriptome assembly. The genetic unit accounted for the largest variation in the gene expression profile, whereas the two populations had contrasting Zn accumulation phenotypes and shared little common response to the Zn treatment. The PL22 population displayed an iron deficiency response at high Zn in roots and shoots, which may account for higher Zn accumulation. By contrast, I16, originating from a highly Zn‐contaminated soil, strongly responded to control conditions. Our data suggest that distinct mechanisms support adaptation to high Zn in soils among A. halleri metallicolous populations. [ABSTRACT FROM AUTHOR]

Rice is an important food crop and zinc (Zn) is a beneficial microelement. However, there are few reports on the effect of zinc on yield and physiological characteristics of rice. In this study, exogenous zinc (ZnSO 4 ·7H 2 O) was applied on plant to explore the effects of zinc on rice yield, quality and photosynthetic capacity. The results showed that appropriate concentration of zinc could increase the net photosynthetic rate (Pn) of rice leaves, and Zn2 (2 mg/L ZnSO 4 •7H 2 O) treatment was the most significant. However, the Zn treatment had no positive effect on rice yield except under the concentration of Zn2. Meanwhile, the result showed that Zn treatment could increase chalkiness degree (CD) and chalky grain rate (CGR), decreased amylose content (AC), increased protein content and changed protein composition of rice. The above indexes were most significant in Zn2 treatment. In addition, the Zn2 treatment significantly increased rapid viscosity analyzer (RVA) of rice. In conclusion, the results of this study suggested that Zn treatment could enhance the photosynthetic capacity of rice leaves, and improve the processing quality, taste quality and nutritional quality of rice. However, it will have a negative impact on the appearance quality of rice and cannot be used to increase rice production. This study will provide a basis for the application of zinc in rice production. [Display omitted] • Zinc can increase the net photosynthetic rate of rice leaves. • Zinc did not have a positive effect on rice yield. • Zinc can increase appearance quality of rice. • Zinc treatment can decrease amylose content, increased protein content of rice. [ABSTRACT FROM AUTHOR]

Enhancement of micronutrient bioavailability is crucial to address the malnutrition in the developing countries. Various approaches employed to address the micronutrient bioavailability are showing promising signs, especially in cereal crops. Phytic acid (PA) is considered as a major antinutrient due to its ability to chelate important micronutrients and thereby restricting their bioavailability. Therefore, manipulating PA biosynthesis pathway has largely been explored to overcome the pleiotropic effect in different crop species. Recently, we reported that functional wheat inositol pentakisphosphate kinase (TaIPK1) is involved in PA biosynthesis, however, the functional roles of the IPK1 gene in wheat remains elusive. In this study, RNAi-mediated gene silencing was performed for IPK1 transcripts in hexaploid wheat. Four non-segregating RNAi lines of wheat were selected for detailed study (S3-D-6-1; S6-K-3-3; S6-K-6-10 and S16-D-9-5). Homozygous transgenic RNAi lines at T4 seeds with a decreased transcript of TaIPK1 showed 28-56% reduction of the PA. Silencing of IPK1 also resulted in increased free phosphate in mature grains. Although, no phenotypic changes in the spike was observed but, lowering of grain PA resulted in the reduced number of seeds per spikelet. The lowering of grain PA was also accompanied by a significant increase in iron (Fe) and zinc (Zn) content, thereby enhancing their molar ratios (Zn:PA and Fe:PA). Overall, this work suggests that IPK1 is a promising candidate for employing genome editing tools to address the mineral accumulation in wheat grains. [ABSTRACT FROM AUTHOR]