Zargar Tahoora Batool, Sobh Mawia, Basal Oqba, Veres Szilvia
Department of Applied Plant Biology, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary.
BMC Plant Biol. 2025 Jan 8;25(1):29. doi: 10.1186/s12870-024-05972-y.
Water deficits, exacerbated by climate change and unpredictable weather, have become a significant global challenge to agricultural productivity. In this context, exogenous melatonin treatment is well documented as a stress alleviator; however, its effects on various biological processes, particularly in less-explored genotypes, remain understudied. This study aimed to enhance water deficit resilience in sweet corn by applying foliar melatonin to four genotypes-Messenger, Dessert, Royalty, and Tyson under two levels of water deprivation induced by polyethylene glycol at 8% and 12% concentrations in a hydroponic, controlled environment.
The melatonin treatments were assessed for their impact on various morphological, physiological, and biochemical parameters under both normal and water-deficit conditions. Under severe water deprivation (12% PEG), melatonin increased root length by 75%, peroxidase activity by 31% while reducing malondialdehyde content by 34% in genotype Dessert indicating enhanced antioxidant defense and reduced oxidative damage. Likewise in genotype Royalty, stomatal conductance increased by 68%, with increasing specific area by 125% on melatonin treatment under severe water deprivation. The treatment also improved chlorophyll-a content by 93% in Royalty and 37% in Tyson, while decrease in malondialdehyde levels by 42% in Tyson, indicating reduced oxidative damage under severe water deprivation. In addition, melatonin increased photosystem II efficiency (Fv/Fm) in all genotypes with 27% increase in Royalty and improved quantum yield across all genotypes, regardless of the water deficit level.
Overall, melatonin treatment showed genotype-specific and dose-dependent effects in mitigating water deficit effects, offering a promising strategy to improve crop resilience and productivity in limited water environments. These results suggest the practical application for integrating melatonin treatments into sustainable agricultural practices, such as improving water deficit tolerance in sweet corn and potentially other crops, to maintain productivity under adverse climatic conditions.
气候变化和不可预测的天气加剧了水分亏缺，这已成为全球农业生产力面临的重大挑战。在此背景下，外源褪黑素处理作为一种应激缓解剂已有充分记录；然而，其对各种生物过程的影响，尤其是在研究较少的基因型中，仍未得到充分研究。本研究旨在通过在水培控制环境中，对四种基因型——信使、甜点、皇室和泰森，在8%和12%浓度的聚乙二醇诱导的两种水分亏缺水平下，喷施叶面褪黑素，来增强甜玉米对水分亏缺的耐受性。
评估了褪黑素处理在正常和水分亏缺条件下对各种形态、生理和生化参数的影响。在严重水分亏缺（12%聚乙二醇）条件下，褪黑素使甜点基因型的根长增加了75%，过氧化物酶活性增加了31%，同时丙二醛含量降低了34%，表明抗氧化防御增强，氧化损伤减少。同样，在皇室基因型中，在严重水分亏缺条件下，褪黑素处理使气孔导度增加了68%，比表面积增加了125%。该处理还使皇室基因型的叶绿素a含量提高了93%，泰森基因型提高了37%，而泰森基因型的丙二醛水平降低了42%，表明在严重水分亏缺条件下氧化损伤减少。此外，褪黑素提高了所有基因型的光系统II效率（Fv/Fm），皇室基因型提高了27%，并且无论水分亏缺水平如何，都提高了所有基因型的量子产量。
总体而言，褪黑素处理在减轻水分亏缺影响方面表现出基因型特异性和剂量依赖性效应，为在有限水环境中提高作物耐受性和生产力提供了一种有前景的策略。这些结果表明，将褪黑素处理整合到可持续农业实践中的实际应用，如提高甜玉米以及可能其他作物的水分亏缺耐受性，以在不利气候条件下维持生产力。
