Arif Hussain

Melatonin, a multifunctional, non‐toxic regulatory molecule, plays a crucial role in enhancing tolerance to abiotic stress, which is tightly linked to S metabolism. Despite the proven efficacy of sulfur (S) in enhancing abiotic stress tolerance, the combined effect of S and melatonin in stress mitigation remains to be elucidated. This is particularly relevant in the context of climate change, where the increased occurrence of waterlogging stress increases the risk of reduced S availability, leading to reduced yield and quality in rapeseed. The objective of this study is to examine the impact of a combination of foliar melatonin and sulfur, when administered to soil or leaves, on the response of plants to waterlogging stress. The experimental design involved the supplementation of rapeseed (Brassica napus L.) plants with sulfur (S) to either the soil (0.2 g kg⁻¹) or the leaves (300 ppm) 5 days prior to stress induction. The plants were subjected to waterlogging at BBCH–31 for a period of 7 days, preceded by a pretreatment 2 days prior to the stress with melatonin (200 μM). In comparison, untreated plants subjected to waterlogging showed a significant reduction in growth, nutrient uptake, photosynthetic activity, and sugar content but an increase in the antioxidant defense system. However, the application of melatonin significantly mitigated the adverse effects of waterlogging stress. In comparison with the control, soil‐S application exhibited higher efficacy than foliar S application in increasing plant resistance, as reflected by improved dry weight (+50%), photosynthesis (+12%), stomatal conductance (+40%), sulfur (+40%), magnesium (+59%), and reduced hydrogen peroxide (−22%) and lipid peroxidase (−26%). This combination also increased antioxidant defense by increasing catalase (+43%), glutathione reductase (+17%), ascorbate peroxidase (+47%), ascorbate (+39%), and glutathione (+40%) contents, in contrast to untreated waterlogged plants. The study underlines the potential of melatonin and sulfur as effective agents to alleviate waterlogging stress.

Vibrio alginolyticus is one of the major disease-causing bacteria in shrimp aquaculture. The widespread use of antibiotics in shrimp aquaculture to treat bacterial diseases has raised concerns about antibiotic resistance. As a result, alternative treatments, such as plant extract phytochemicals are being explored to mitigate these risks. This study aims to identify promising biologically active compounds from garlic (Allium sativum) that can inhibit the virulent protein thermolabile hemolysin of V. alginolyticus, which causes shrimp vibriosis. Various computational approaches, including molecular docking, pharmacokinetic analysis, and molecular dynamics simulation, were conducted to predict the compounds that can inhibit the phospholipase and hemolysis activities of the thermolabile hemolysin protein. Out of thirty-five compounds from A. sativum, protopine (CID 4970), gibberellin A7 (CID 92782), and gibberellic acid (CID 6466) demonstrated the strongest binding affinities, with scores of -9.4, -8.0, and -7.4 kcal/mol, respectively. Pharmacokinetic and toxicity analyses showed favorable drug-like properties for gibberellin A7 and gibberellic acid with no violations. Molecular dynamics simulations demonstrated that gibberellin A7 and gibberellic acid exhibited the highest stability over 100 nanoseconds. The investigation shows that gibberellin A7 and gibberellic acid from A. sativum have the potential to inhibit the virulent activity of thermolabile hemolysin. However, the study needs further in-vitro and in-vivo analysis to test our predicted results.

Cadmium (Cd), being a highly toxic heavy metal, significantly impacts plant growth and development by altering nutrient uptake and causing oxidative and structural damage, resulting in reduced yield. To combat Cd toxicity and accumulation in wheat, it was hypothesized that co-application of Selenium (Se) and Silicon (Si) can reduce the adverse effect of Cd and regulate Cd resistance while improving Se fortification in wheat. Therefore, this study evaluated the comparative effect of Se and Si on the growth and antioxidant defense systems of wheat plants grown in a hydroponic setup. Briefly, the plants were acclimatized to the hydroponic solution for 1 week and then exposed to 10 µmol Cd. Afterwards, the treatments, including 0.2 mmol Si and 1.5 µmol Se, were applied as a root and foliar application, respectively. Plants supplemented with both Se and Si showed improved biomass and other physiological growth attributes, and this response was associated with improved activity/contents of antioxidants, including glutathione (GSH) content, glutathione reductase (GR), ascorbate peroxidase (APX), and catalase (CAT), with related lowering of hydrogen peroxide, malondialdehyde content, and structural damages. Moreover, by Se + Si supplementation, a decrease in total S levels in plant tissues was observed, whereas an increase in total protein concentration and GSH indicated a different and novel mechanism of Cd tolerance and S homeostasis in the plant. It was observed that Si was more involved in significantly reducing Cd translocation by stabilizing Cd in the root and reducing its content in the soluble fraction in both the root and shoot. Whereas Se was found to play the main role in reducing the oxidative damage caused by Cd, and the effect was more profound in the shoot. In addition, this study also observed a positive correlation between Si and Se for relative uptake, which had not been reported earlier. Our findings show that the Se and Si doses together benefit growth regulation and nutrient uptake; additionally, their combinations support the Cd resistance mechanism in wheat through upregulation of the antioxidant system and control of Cd translocation and subcellular distribution, ultimately contributing to the nutritional quality of wheat produced. Thus, it is concluded that the co-application of Se and Si has improved the nutritional quality while reducing the Cd risk in wheat and therefore needs to be employed as a potential strategy to ensure food safety in a Cd-contaminated environment.

Waterlogging significantly impacts plant growth and development by altering nutrient uptake and antioxidant enzyme functions, resulting in reduced yield. Plants need sulfur (S) to produce reduced glutathione (GSH), a thiol compound that combats abiotic stresses. It is hypothesized that supplying S to high S-demanding oilseed rape plants beyond its growth requirements can reduce the adverse effect of waterlogging stress. Therefore, this study evaluated the comparative effect of different S doses (mg kg^− 1 soil), i.e., no-S (S₀), low-S (S₁, 35), medium-S (S₂, 70), and high-S (S₃, 140) on growth, yield and antioxidant defense systems of normal growing and waterlogged oilseed rape plants. Waterlogging was imposed at the inflorescence emergence stage for 7 days by retaining a 3-cm layer of water above the soil surface. Waterlogged plants supplemented with high-S showed improved growth and higher yield than those supplemented with lower S levels, and this response was associated with improved activity/contents of antioxidants, including ascorbate (AsA), GSH, ascorbate peroxidase, catalase, glutathione reductase, glutathione peroxidase, glutathione S-transferase, monodehydroascorbate reductase, and dehydroascorbate reductase, with concomitant lowering of hydrogen peroxide, dehydroascorbate and malondialdehyde content. Furthermore, leaf S concentration was enhanced in waterlogged plants treated with high-S, while anions were regulated whereby Cl⁻ uptake was decreased. However, under control conditions, high-S did not provide additional benefits of improved plant growth, yield, and antioxidant activities compared to the medium-S application. Thus, it is concluded that additional S supplementation mitigates the adverse effects of waterlogging stress on oilseed rape, and needs to be employed as a potential strategy to alleviate the negative effects of this abiotic stress.

Background: Waterlogging at early and later growth stages could affect sulfur (S) uptake, distribution, yield, and quality of winter wheat. We hypothesized that the hybrid winter wheat variety (Hyvento), with a high degree of heterosis and genetic diversity, is likely to uptake and utilize S more efficiently and withstands waterlogging better than the inbred wheat variety (Kredo).Aims: The objective of the present study was to investigate the effect of 2‐week waterlogging at the end of tillering stage (Feekes Stage 6) and/or ear emergence stage (Feekes Stage 10.1) on grain yield, yield components, S‐uptake and its partitioning, and composition of grain storage proteins (glutenins and gliadins) of hybrid (Hyvento) and inbred (Kredo) winter wheat varieties.Methods: Plants were grown in large containers (120 L) in a semi‐controlled greenhouse and harvested three times immediately after each waterlogging treatment and at agronomic maturity. Grain yield, S concentration in different plant organs, total protein content, and patterns of gluten proteins (gliadin and glutenin) and their subunits (by sodium dodecyl sulfate–polyacrylamide gel electrophoresis) in grains were evaluated.Results: Grain yield of the inbred variety was more negatively affected under early and late waterlogging than the hybrid variety and was associated with reduced grain size. The decline in grain yield was significantly higher under late waterlogging (30%–31%) than early waterlogging (17%–18%). Compared to the hybrid variety Hyvento, the waterlogging‐induced decline in S concentration in grains, husk, and straw was markedly lower in the inbred variety Kredo. While early waterlogging did not affect total grain protein content in either of the varieties, late waterlogging significantly reduced the total grain protein content (18%) in the inbred variety Kredo. Similarly, the grain gliadin content of the hybrid variety was not affected by both waterlogged conditions, whereas 32% and 23% reductions were recorded for the inbred variety under early and late waterlogging, respectively. Nevertheless, waterlogging significantly increased the proportion of S‐poor high‐molecular‐weight glutenin subunits and ω‐gliadin in the inbred variety.Conclusion: It could be inferred from the present study that hybrid winter wheat variety is relatively resistant to waterlogging than the inbred wheat variety, and thereby produces higher grain yield. Efficient uptake and metabolism of S could be one of the mechanisms conferring waterlogging resistance in winter wheat.

Yield Potentiality and Grain Physio-Chemical Properties of Some Advanced Lines and High Yielding Varieties of Rice in Bangladesh