Plant Protein Content Research Articles

Effect of Foliar Applied Acetylsalicilic Acid on Wheat (Triticum aestivum L.) under Field Conditions

The exogenous application of salicylic acid prevents plant damage caused by various abiotic stresses (drought, high and low temperatures, salinity) and helps plants to build resistance to biotic stresses (pathogens). Acetylsalicylic acid, which is a synthetic salicylic acid derivative, has the same properties. In the face of climate change and a greater likelihood of extreme weather events, the use of these acids can significantly help to ensure proper growth and development of plants, especially sensitive species, even under stress conditions. The problem, however, is choosing the right dose (concentration) and time of application, and individual species sensitivity. The aim of the study was to assess the effect of acetylsalicylic acid on the growth and yield parameters of spring wheat. A field trial was carried out in 2013 and 2014 at the Institute of Plant Protection—National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv. ‘Tybalt’, in four replications. Acetylsalicylic acid was tested in two concentrations: 0.3 and 0.5 mM. Each concentration was applied to the crop twice at growth stage BBCH 29 (end of tillering) and 7 days afterwards, and at growth stage BBCH 37 (flag leaf just visible) and 7 days afterwards. The study evaluated 12 traits of the crop, including plant height, chlorophyll content in the flag leaf, length of the ear, and quality and quantity parameters of the yield. The study showed that both the selection of the appropriate concentration and the time of acetylsalicylic acid application have a significant impact on the growth and development of the wheat. The acetylsalicylic acid increased the amount of chlorophyll in the leaves, the number of grains in the ear, the mass of a thousand grains, and grain yield. The present study did not confirm significant differences between the acetylsalicylic acid concentrations. The concentration of 0.5 mM proved more effective only for such traits as plant height and protein content in the grain. The study showed that it is not the concentration but the time of acetylsalicylic acid application that is more important for the growth of the wheat. Although there were no significant differences between the effects of earlier and later application time on plant height or chlorophyll content, most of the structural and qualitative parameters of the yield (number of grains in the ear, grain density, grain hardness, protein, gluten and starch content) were better after later application of acetylsalicylic acid (GS BBCH 37).

Performance of Zea mays L. cultivars in tannery polluted soils: Management of chromium phytotoxicity through the application of biochar and compost.

Soil contamination with heavy metals caused by various industrial activities is a threatening global environmental issue of the current era. Chromium (Cr) is the most toxic heavy metal used in leather industry and disposal of untreated wastewater into natural water bodies leads to contamination of natural soil and water resources. We studied the combined effect of biochar and compost on improving the tolerance to Cr toxicity by enhancing the morpho-physiological and biochemical attributes of two maize cultivars (P-1543 and NK-8441) grown in tannery waste polluted soils. The results of this study reveal that Cr toxicity reduced the plant growth by affecting physiological and biochemical attributes. Here, compost and biochar application significantly increased the plant biomass (fresh and dry), height, photosynthesis, chlorophyll content, water relation, starch, and protein content over treatment set as control. However, significant decline in electrolyte leakage (EL), proline, lipid peroxidation, soluble sugars, and antioxidant enzymes (APX, GPX, GR, GST, GSH, SOD, and CAT) was observed by combined application of compost and biochar. Hexavalent chromium concentration was maximum decreased to 4.1μg g-1 in soil after post-harvesting of maize cultivar NK-8441, while in roots and shoots to 22.6 and 19.2μg g-1 of maize cultivar P-1543, respectively, by combined application of compost and biochar. Moreover, these both amendments in combination showed considerably better results than their sole application and cultivar P-1543 comparatively performed better than NK 8441, in both K and S soils. Correlation and principal component analysis (PCA) revealed mostly highly positive associations among all the studied morpho, physio, and biochemical attributes of maize plant with the few exceptions, particularly concentration of Cr(III) and Cr(VI) in soil. The present work concluded that combined use of biochar and compost has great potential to decrease Cr toxicity and improve plant growth in tannery polluted soils.

Применение новых комплексных удобрений и биологических препаратов на посевах кормовой озимой ржи в условиях Псковской области

Abstract. The development of optimal nutritional system for agricultural crops is one of the main factors for the getting of stable yields. The deficiency of some macro- and microelements in plant nutrition, leading to yield decreasing, can be compensated with new complex of balanced fertilizers and biological products. The aim of the work is to study the effect of nitrogen fertilization, new forms of complex fertilizers based on active biological substances (“Kodamin B-Mo”, “K-Gumat-Na”, “Agroflorin” “Auksinolen”) and the microbiological preparation (MBP) “Bisolbifit” on the yield and quality of grain of fodder winter rye “Novaya Era” on sod-podzolic soils in the Pskov region. The originality is that for the agro-ecological conditions of the Pskov region, the influence of new complex fertilizers, biological and humic preparations in the cultivation of winter rye has been studied. Methods. The research was carried out in 2019 on the experimental field of the laboratory of agricultural technologies of the Federal research center for Bast Crops (Pskov Department). The records, observations and analyzes were carried out according to generally accepted methods. Results. The maximal positive effect on grain yield was made with the introduction of complete mineral fertilizer in doses of N80P40K70 with fractional nitrogen application: 20 kg of active substance – in the main fertilizer, 40 kg – in the tillering phase and 20 kg – in the booting phase. Up to 1,3 t/ha or 42.2 % to the control level were obtained in that variation. Application of mineral fertilizers in a dose of N40P40K70 and MBP “Bisolbifit” increased on 0,4 t/ha of grain, which amounted 10.6 %. Foliar double treatment of plants with fertilizer “Kodamin B-Mo” increased grain yield up to 8.6 %. The influence of the investigated factors on the protein content and nitrate nitrogen in plants of fodder winter rye, the weight of 1000 seeds and the structure of the yield was established. For 1 kg of active substance of mineral fertilizers at various doses of nitrogen fertilizing the additional yield of grain from 3.68 to 6.39 kg was obtained.

Morpho-physiological changes in carrots by foliar γ-aminobutyric acid under drought stress

The present study was aimed to investigate the effects of foliar spray of γ-aminobutyric acid (GABA) on the morpho-physiological traits of water-stressed carrot cultivars (Supertaj and Bharat). The different levels of GABA (0, 1, 2, and 4 mM) were sprayed after 20 days of carrot germination grown under 100% and 50% field capacity of soil moisture. The samples were taken after 2 weeks of GABA application and morphological characteristics, integrity of cell-membrane, photosynthetic pigments, and enzymatic antioxidants were measured. The results revealed that the foliar application of GABA improved the vegetative growth and significantly increased the levels of free amino acids, plastid pigments, enzymatic antioxidants, and the relative water content in the roots grown under 50% field capacity as compared to control. Additionally, the GABA application decreased the electrolyte leakage of ions and malondialdehyde content in carrot leaves. The protein contents of GABA-treated carrot plants did not significantly vary with untreated plants. In conclusion, the application of GABA for the production of carrots may help plants to mitigate the adverse effects of water deficit stress.

Employ of arbuscular mycorrhizal fungi for pharmaceuticals ibuprofen and diclofenac removal in mesocosm-scale constructed wetlands

This study investigated the effects of arbuscular mycorrhizal fungi (AMF) colonization on the growth of wetland plants (Glyceria maxima), and treatment performance in constructed wetlands (CWs) under the stress of pharmaceuticals ibuprofen (IBU) and diclofenac (DCF). Results showed that the growth of G. maxima was significantly increased by AMF colonization. AMF significantly increased the activities of antioxidant enzymes (peroxidase and superoxide dismutase) and soluble protein content in wetland plants, but the contents of malondialdehyde and O2•− were reduced. The removal efficiencies of TOC, PO43−-P, NH4+-N, and TN were increased in AMF+ treatments by 6%, 11%, 15% and 11%, respectively. AMF increased the removal efficiencies of IBU and DCF by 6–14% and 2–21%, respectively, and reduced the content of their metabolites (2-OH IBU, CA IBU and 4′-OH DCF) in the effluent. Besides, the presence of AMF increased the contents of IBU and DCF in plant roots, while decreased their transportation to shoots. AMF symbiosis decreased the contents of IBU metabolites (2-OH IBU and CA IBU) but increased the contents of DCF metabolite (4′-OH DCF) in the roots of the host plant. In conclusion, these results indicated that AMF plays a promising role in CWs for emerging pollutants removal.

Organic nitrogen modulates not only cadmium toxicity but also microbial activity in plants

It is known that organic nitrogen may modify uptake and toxicity of metals but direct metabolic and microbial comparison of various organic N sources is not available. We therefore studied comparative impact of additional N sources (nitrate, urea or allantoin as 1 mM of N for each compound in addition to 15 mM of inorganic N in the Hoagland solution) on Cd toxicity and microbial activity in common crop cucumber. Organic N significantly elevated the growth, chlorophyll content and photosynthetic activity under Cd excess in comparison with inorganic N though the impact on Cd uptake was negligible. Both organic N compounds also affected accumulation of mineral nutrients, total N, amino acids, and protein content in Cd-stressed plants. Among organic acids, mainly allantoin and partially urea affected accumulation of citrate and tartrate. The most notably, we detected that allantoin was decomposed even within 24 h by microbes into the urea, but it significantly elevated rhizosphere microbial activity. All these data indicate that allantoin is metabolized by plants/microbes into the urea and that it affects microbes mainly in the rhizosphere, which could contribute to amelioration of Cd toxicity.

Uptake, accumulation, and translocation mechanisms of steroid estrogens in plants

Applying sewage sludge or animal manure onto agricultural land can result in estrogen pollution, which increases the risk of human exposure to steroid estrogens (SEs) via the food chain. However, the uptake and accumulation mechanism of SEs by plants is still unclear. In this study, the uptake, accumulation, and translocation of 17β-E2, a representative SE, were investigated through a series of wheat hydroponic experiments. Various inhibitors were applied to explore the uptake pathways of 17β-E2 by wheat. In addition, the effects of exposure concentrations, coexisting 17α-ethynylestradiol (EE2) and plant properties on the uptake of 17β-E2 were examined. The results indicated that the accumulation of 17β-E2 in wheat roots mainly resulted from adsorption and active uptake that involved aquaporins and anion channels transport. The chlorophyll and protein contents of plants were positively correlated with the uptake of 17β-E2, whereas competitive inhibition occurred when 17β-E2 and EE2 coexisted in the same solution. Nevertheless, the results of a split-root experiment showed that 17β-E2 absorbed by wheat could further migrate in plant via long-distance transport and ultimately was discharged from plants, suggesting that 17β-E2 was still at risk of being released even though it had been absorbed by plants. These results could provide valuable insights into the risk assessment and risk control of the uptake of SEs by plants.

Nitrogen fertilizer decreases survival and reproduction of female locusts by increasing plant protein to carbohydrate ratio.

Nitrogen limitation theory predicts that terrestrial plants should benefit from nitrogen inputs and that herbivores should benefit from subsequent higher plant protein contents. While this pattern has generally been supported, some herbivorous insects have shown preference and higher performance on low protein (p), high carbohydrate (c) diets as juveniles. However, little is known about the effects on reproduction in adults. Using nitrogen fertilizer, we demonstrate that high plant p:c has negative effects on Senegalese locust (Orthoptera: Oedaeleus senegalensis) reproduction and survival in an agroecological setting. For this, we measured p:c in millet plants Pennisetum glaucum that received two levels of fertilizer (high and moderate) and a control, then we caged locusts on these plants for 2weeks. In the laboratory, we gave locusts the choice between untreated millet leaves and leaves that received one of the two fertilization treatment. We found that fertilization increased p:c ratio in a concentration-dependent fashion. We counted the number of locusts alive over the course of 2weeks and showed that fewer females survived on fertilized plants than on control plants. Females that ate plants from the high fertilization treatment laid lighter eggs. Finally, we showed that female locusts prefer unfertilized plants to plants with a high p:c. We hypothesize that this pattern will apply broadly to species that have extensive carbohydrate needs, such as long-distance migrators. Because many ecological studies focus primarily on nitrogen or protein, and fail to consider carbohydrates, this study has important implications for how ecologists consider nutrient limitation of primary consumers in ecosystems globally.

Combining Ability and Gene Action Analysis for Seed Yield and Component Traits in F2 Generation of Vigna mungo L. Hepper by using Griffing Approach

Background: Urdbean (2n=2x=22), also known as blackgram is an important short duration legume crop belonging to family Fabaceae, widely cultivated in Asia. Urdbean occupies an important position among pulses owing to its high seed protein (25-26%), carbohydrates (60%), fat (15%), minerals, amino acids and vitamins. Owing to its low water requirement, it is also suitable for rainfed conditions. It adapts well to various cropping systems owing to its ability to fix atmospheric nitrogen in symbiosis with soil bacteria, rapid growth and early maturity. Half diallel analysis was adopted in present study to gather information on gca (general combining abilities) and sca (specific combining abilities) of 6 diverse parents and simultaneously estimating various types of gene effects involved in the expression of seed yield and related attributes in urdbean. Methods: The F1’s were developed during 2017 in 9 x 9 half diallel fashion by Sharma et al. 2019 and these F1’s were evaluated. Significant crosses on the basis of gene action and combining ability were selected for further advancement. The experimental material comprised of the six parents and 15 F2’s of a 6 x 6 half diallel cross among six cultivars of urdbean (four are purelines viz., Palampur-93, HPBU-111, DU-1 and KU-553 and rest of the two are advanced and indigenous lines viz., Him Mash-1 and IC-281994). The F2’s along with the parental genotypes were grown in a Randomized block Design (RBD) with three replications at Experimental Farm of the Department of Crop Improvement, COA, CSK HPKV Palampur (H.P.) during Kharif, 2018. Results: The cross combination, Him Mash-1× HPBU-111, was identified the best for high seed yield on the basis of sca. The specific crosses, Palampur-93 × IC-281994, Palampur-93 × KU-553 were good specific combiners for most of the traits viz., plant height, branches per plant, pods per plant, biological yield per plant, seed yield per plant, harvest index, 100-seed weight and crude protein content.

Synthesis and application of controlled size copper oxide nanoparticles for improving biochemical and growth parameters of maize seedling

Nanoparticles can enhance growth and yield of different plants due to their favorable physicochemical properties. This study investigated the effect of copper oxide (CuO) nanoparticles on biochemical and growth parameters of maize seedling. CuO nanoparticles were synthesized by co-precipitation method and characterized for their chemical composition, structure, surface morphology and size distribution. The size distribution was found in the range of 11–28 nm. The majority nanoparticles exhibited sizes between 20 and 26 nm. The effect of these nanoparticles on catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), sugar level, protein, and chlorophyll content of maize plants was investigated during early growth stages. A randomized block design was used to quantify the effect of CuO concentration on maize seedling. It was revealed that CuO nanoparticles have a stimulating effect on the growth of plantlets. However, high CuO concentrations induced an inhibitory effect on plant growth parameters. CAT, SOD, and POD were more influenced by 550 ppm concentration whereas sugar level, protein and chlorophyll content were more affected by 800 ppm concentration. Outcomes of present study reveal that CuO-NPs have the potential to increase growth and yield of maize, but their effect is concentration dependent. Further research is required to explore the best effective concentration of CuO-NPs and mode of applications for yield maximization of maize.

Biosynthesis of ZnO Nanoparticles Using Bacillus Subtilis: Characterization and Nutritive Significance for Promoting Plant Growth in Zea mays L.

Nano-fertilizer(s), an emerging field of agriculture, is alternate option for enhancement of plant growth replacing the synthetic fertilizers. Zinc oxide nanoparticles (ZnO NPs) can be used as the zinc source for plants. The present investigation was carried out to assess the role of ZnO NPs in growth promotion of maize plants. Biosynthesized ZnO NPs (using Bacillus sp) were characterized using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), X-ray diffraction (XRD) and Zeta potential. Different concentrations of ZnO NPs (2, 4, 8, 16 mg/L) were explored in pot culture experiment. Size of ZnO NPs ranged between 16 and 20 nm. A significant increase in growth parameters like shoot length (61.7%), root length (56.9%) and significantly higher level of protein was observed in the treated plants. The overall pattern for growth biomarkers including the protein contents was maximum at 8 mg/L of ZnO NPs. It was observed that application of biosynthesized ZnO NPs has improved majority of growth biomarkers including plant growth parameters, protein contents and leaf area. Therefore, biosynthesized ZnO NPs could be considered as an alternate source of nutrient in Zn deficient soils for promoting the modern agriculture.

Biological Control of Fusarium Wilt Disease of Tomato Plants Using Seaweed Extracts

The present research was conducted to evaluate the marine algal extracts effectiveness on tomato Fusarium wilt disease. The organic extracts of macroalgae exhibited antagonistic activity against Fusarium oxysporum. The highest antifungal activity obtained from the methanolic extract of Cystoseira myrica followed by methanol extract of Sargassum cinereum. GC–mass analysis of some seaweed extracts was used to identify the presence of main compounds as dimethylocta-1,6-dien-3-ol,1-methoxy-4-(2-propenyl), hexadecanoic acid, methyl ester, and octadecanoic acid, and methyl ester. The infection of tomato plants with F. oxysporum induced a significant decrease in shoot and root dry weights as well as the photosynthetic pigments. There was a marked increase in soluble contents of saccharides and protein for infected tomato plant shoots and roots. On the other hand, pathogenicity stress induced a significant decrease in total contents of saccharides and protein of tomato shoots and roots. The results indicated a significant increase in total free amino acid content and antioxidant enzymes (CAT, POD, and APX) activities of inoculated tomato shoots and roots. The plant fresh and dry weights increased significantly by increasing its pigments content as a result of marine algal extracts application. On the other hand, algal extracts pretreatment decreased soluble saccharides and protein contents of plants, whereas increased significantly amino acid content in shoots of the inoculated plants. The increase in the activity of antioxidant enzymes played an essential role in increasing plant resistance against F. oxysporum. Finally, the marine macroalgae could serve as a new bioagent source for biological control of soil fungi.

Woody vegetation remnants within pastures influence locust distribution: Testing bottom-up and top-down control

Agriculture is a major factor in landscape fragmentation, altering nutrient cycling and animal and plant populations through increasing habitat edge density. Most research on insect herbivores in agroecosystems has focused on the top-down effects of predators moving throughout the habitat mosaic. Few studies have focused on the top-down and bottom-up factors modulating the distribution of insect herbivore populations between natural and agricultural patches. For example, despite an understanding that Australian plague locusts (Chortoicetes terminifera) avoid tree patches, the underlying mechanisms remain unknown. Here, we explored how wooded remnants within pastures affect locust density and the potential top-down and bottom-up mechanistic explanations. We tested three hypotheses: 1) grasses near wooded areas are nutritionally suboptimal, 2) predator density is higher near wooded areas, and 3) temperatures are cooler underneath trees. We measured locust density, grass nutrient content, predator abundance, temperature, and ground cover along 50 m transects from wooded areas to open grassy areas. We ran those transects in three fields and had four transects per field. We confirmed locust avoidance for trees at a 20 m periphery, however none of the variables tested independently explained this trend. Grass nutrient content was similar underneath wooded areas and in open patches. Predator abundance did not differ between the two habitats. The ground was warmer under wooded areas than in grassy areas potentially due to woody vegetation negating windchill. Further, we found that locust density was negatively correlated with plant protein content and was highest in areas with approximately 20 % bare ground cover. Both plant protein and ground cover are important for grasshopper performance and reproduction. It is likely a complex interaction between these variables and others that drive the distribution of this species and other insect herbivores in agroecosystems. The small-scale mechanisms driving the response of insect herbivores to landscape changes is critical to understanding and predicting population dynamics at large-scales.

Palatability of common cover crops to voles (Microtus)

Use of cover crops in intensive row-crop agriculture has dramatically increased over the last decade. Cover crops provide vegetative cover and forage that may support more diverse and abundant rodent communities than those found in conventional row-crop agroecosystems. However, increasing vole populations can lead to depredation of the soybean (Glycine max) commodity crop. We tested for selection of 13 commonly planted cover crops and 4-5 additional benchmark species by meadow (Microtus pennsylvanicus) and prairie (M. ochrogaster) voles using cafeteria-style feeding trials conducted in semi-natural outdoor enclosures. Red clover (Trifolium pratense), alfalfa (Medicago sativa), and hairy vetch (Vicia villosa) were commonly preferred among vole species, and canola (Brassica napus) was avoided. Meadow and prairie voles consistently chose or avoided highly and minimally preferred species, respectively, but were more variable in choosing moderately preferred species. Consumption scores were negatively associated with the number of plants offered in a trial, and the relationship was stronger for males than females. The interaction of protein and fiber content of plants, and vole identity included as a random effect, were also important in predicting score probability for both vole species. Identifying minimally preferred plants and factors that influence selection may allow farmers to manage cover-cropped soybean fields to discourage immigration of small mammals into fields, thus reducing negative consequences that might otherwise limit future adoption of a valuable soil conservation practice.

Productivity and economic indicators of sweet maize silage treated with diazotrophic bacteria and thiamine

Objective. Evaluate the productivity, sweet maize plants characteristics, crude protein and economic indicators of the production of sweet maize silage inoculated with Azospirillum brasilense and thiamine as seed treatment (0; 15; 30; 45 mg kg-1). Material and Methods. Biometric characteristics, productivity, crude protein content were evaluated, and the total operational cost structure was used to determine the economic indexes of a productive cycle. Results. It was observed that treatments with isolated or combined application of A. brasilense and thiamine did not affect the plant height, stem diameter, fresh and dry mass productivity and crude protein contents of sweet maize plants. However, the inoculation with A. brasilense increased in 24.36%, 24.36%, 53.15% and 10.47%, the productivity of fresh matter, gross revenue, operating profit and the profitability index, respectively, compared to the control treatment. Even with different responses, all treatments resulted in positive profitability indices, indicating the appropriate economic return with this activity. Conclusions. It was concluded that A. brasilense and thiamine applied as seed treatment do not significantly affect sweet maize plants development and composition; treatments influenced the economical indexes, and the isolated application of A. brasilense resulted in higher earnings; thiamine isolated application as seed treatment can be used as an alternative for improvement of economical gains.

Effects of antimony contamination in soil on the nutrient composition of three green leafy vegetables

This study aims to explore the effects of antimony (Sb) on the nutrient composition of green leafy vegetables. Red beets (Beta vulgaris L.), mallow (Malva sinensis Cavan.), and Chinese cabbage (Brassicacampestris L.) were planted by pouring antimony solution in flowerpot, then the protein content of plants and the changes of seven nutrient elements such as Ca, Mg, Fe, Mn, Zn, Cu, and I under Sb stress were studied. The results showed that the red beet had the highest protein content when the concentration was 20 mg L−1, which was 0.2856 gprot L−1. With an increase in the antimony concentration, the protein content decreased gradually, and the protein content of mallow and Chinese cabbage did not change significantly. For nutrient elements, except for Ca and I, other nutrients in red beets increased with the increase in antimony concentration, and Mn and Zn contents in mallow were reduced to the lowest when Sb was treated with 100 mg L−1, while content of I element was the highest at 100 mg·L−1, and the content of nutrients in Chinese cabbage changed in a small range. The research showed that the antimony pollution had a great influence on the protein content of red beet. The nutrient content of mallow was fluctuated greatly when Sb was treated with 100 mg L−1. The content of Mn, Zn, and Cu in Chinese cabbage almost did not change due to the antimony concentration.

THE EFFECT OF FOLIAR APPLICATION OF AMINO ACIDS ON THEIR CONTENT AND COMPOSITION IN WINTER WHEAT GRAIN

Field experiments were carried out at the Experimental Station of Vytautas Magnus University (54º52′ N, 23º49′ E) in Lithuania. Winter wheat was grown on the background of N150P90K90 mineral fertilization and was additionally foliar-fertilized with different concentrations of amino acid solutions (0.5-3.0%) at stem elongation and heading stages. The study was aimed to establish protein content as well as quantitative and qualitative distribution of amino acids in winter wheat grain as influenced by fertilization with different concentrations of amino acids. Experimental evidence showed that solutions with different concentrations of amino acids applied at winter wheat stem elongation and heading stages increased grain protein content and total amino acids contents. Plants, fertilized with amino acids solutions at stem elongation stage accumulated higher protein content by on average 4.8%, at heading stage by 4.5% compared with the grain protein content of plants that had not received amino acids fertilization. The total amino acids content in winter wheat grain in response to amino acids applied at stem elongation stage increased by on average 2.0 g kg-1, at heading stage by 5.3 g kg-1. Nonessential and essential amino acids content in winter wheat grain was significantly increased by 2.5 and 3.0% amino acids solutions, applied at stem elongation stage by 0.5, 1.0, 1.5% amino acids solutions applied at heading stage. Winter wheat fertilization with amino acids solutions at stem elongation stage mostly increased the content of glutamic acid, at heading stage mostly increased the contents of glutamic, aspartic, valine, isoleucine, leucine, phenylalanine, methionine, threonine and lysine acids.

Combined application of biochar and sulfur regulated growth, physiological, antioxidant responses and Cr removal capacity of maize (Zea mays L.) in tannery polluted soils

Soil contamination due to heavy metals is a serious problem worldwide. Leather industry is one of the leading sectors in this regard in Pakistan, discharging heavy metal chromium (Cr) through untreated wastewater. In this study, effect of biochar and elemental sulfur (ES) were evaluated on maize growth, physiology, redox homeostasis and Cr dynamics in tannery polluted soils. Biochar was produced through pyrolysis of sugarcane bagasse at 350 °C and was applied at a rate of 3% (w/w) along with different rates of ES (3 and 6 g kg−1 soil). Results revealed that Cr toxicity in tannery polluted soils negatively affected plant growth, physiological and biochemical attributes. Reduction in plant growth and accumulation of Cr(III) and Cr(VI) in roots and shoots were higher in Sialkot (S) soil compared to Kasur (K) soil. Application of biochar and ES (6 g kg−1) resulted in maximum increase in plant height, biomass, chlorophyll content, photosynthesis, relative water, starch and protein content, as compared to control. While electrolyte leakage, soluble sugars, proline content, lipid peroxidation and antioxidant enzymes (APX, CAT, GSH, GR, GPX, GST and SOD) were decreased by addition of biochar and ES in tannery polluted soils. Similarly, combined application of biochar and ES decreased Cr concentrations in soil, and reduced uptake of Cr(VI) and Cr(III) concentration in roots and shoots of plants in S soil compared with K soil. In conclusion, application of biochar in combination with ES could be considered an interesting environmentally sound option for remediation of tannery polluted soils.

Acclimation strategy and plasticity of different soybean genotypes in intercropping.

In response to shading, plant leaves acclimate through a range of morphological, physiological and biochemical changes. Plants produce a myriad of structurally and functionally diverse metabolites that play many important roles in plant response to continually changing environmental conditions as well as abiotic and biotic stresses. To develop a clearer understanding of the effects of shade on soybeans at different growth stages, a comprehensive, three-year, stage-wise study was conducted. Leaf area, leaf thickness, stem diameter, chlorophyll contents, photosynthetic characteristics and other morphological and physiological features were measured along with biochemical assays for antioxidants such as superoxide dismutase, peroxidase and caralase and yield attributes of different soybean genotypes (Guixia 2, Nandou12, Nandong Kang-22, E61 and C103) under shading nets with 50% light transmittance. It was observed that early shading (VER1 and VER2) significantly decreased main stem length and main stem length/stem diameter. Later shading (R1R8 and R2R8) had significant effects on morphological characters such as branch number and pod height. In Nandou 12, the protein contents in plants shaded at R1R8, R2R8 and R5R8 were 9.20, 8.98 and 6.23% higher than in plants grown under normal light levels (CK), respectively, and the crude fat content was 9.31, 10.74 and 4.28% lower. The influence of shading in the later period on anatomy was greater than that in the earlier period. Shading reduced the light saturation point (LSP), the light compensation point (LCP) and the maximum photosynthetic rate (Pnmax), and increased the apparent quantum yield (AQ). Shading also increased the antioxidant enzyme activity in the plants, and this increase was greater with early shading than late. The variability in the chlorophyll (a + b) content and the chlorophyll a/b ratio in R2 stage plants was less than in R5 stage (VER5) plants. Similarly, the activity of antioxidant enzymes in R2 after returning the plants to normal light levels (VER2) was lower than in R5 after relighting (VER5). Compared with later shading, the early shading had a greater effect on the photosynthetic and related characteristics. The longer the shading time, the greater the adverse effects and the less able the plants' were to recover. The data collected in this study contribute to an understanding of the physiological mechanisms underlying the early and late growth stage acclimation strategies in different soybean genotypes subjected to shade stress.

Exogenous application of 24-epibrassinosteroid mitigates NaCl toxicity in flax by modifying free amino acids profile and antioxidant defence system.

In the present study, we investigated the ameliorative effects of 24-epibrassinosteroid (24-epiBL) on antioxidant response and ion homeostasis in two NaCl-stressed Linum usitatissimum L. (flax) cultivars differing in salt tolerance. The content and profile of amino acids were also studied in the tolerant cultivar. Salt stress differently altered the activity of antioxidant enzymes, phenol and flavonoid contents, total antioxidant capacity and ion homeostasis in both cultivars, whereas H2O2 and malondialdehyde (MDA) contents were induced only in the TN-97-95 cultivar. Free amino acid concentrations showed variable patterns under salinity conditions compared with the control plants. 24-epiBL decreased the soluble protein content in NaCl-treated plants and also decreased stimulatory effects of salinity on the production and accumulation of phenol and flavonoid contents and antioxidant capacity with altered ion (Na+, K+, and Cl-) contents. The 24-epiBL reduced the chlorophylls (a, b) and carotenoid contents in salt-treated TN-97-95 cultivar while enhanced the activity of antioxidant enzymes and declined the H2O2 content and lipid peroxidation in both NaCl-stressed cultivars. The profile and content of amino acids were significantly changed by 24-epiBL application under salinity treatment. In summary, our findings demonstrate that 24-epiBL seed priming mitigates the deleterious effects of salt stress in flax plants.