Drought stress is a major limitation in enhancing agricultural productivity in order to fulfill the food demand for the world's population. Fertigation of plants with a variety of biochemicals is being used to create drought resistance in wheat, however, the previous work has been limited in addressing? these issues in plants at different growth stages. Therefore, a greenhouse study was conducted to ameliorate the drought stress in two wheat varieties (Chakwal-50 and Faisalabad-2008) by foliar application of 24-epibrassinolide (EBL). It was evident that drought stress had a negative effect on the growth, photosynthesis, and yield of wheat plants. EBL significantly enhanced the plant growth both under optimal and drought conditions. EBL improved the plant height, spike length and the dry weights of roots, shoots and grains as compared to control. Furthermore, the foliar application of EBL positively enhanced the osmolyte accumulation, increased the amounts of photosynthetic pigments, and improved the gas exchange parameters. The EBL minimized the oxidative stress by reducing electrolyte leakage, malondialdehyde, and hydrogen peroxide contents whereas it enhanced the activities of antioxidant enzymes such as catalase, superoxide dismutase and peroxidase under drought stress. The EBL significantly improved the level of stress hormones such as abscisic acid, indol acetic acid, and cytokinin under drought stress. The growth response of Chakwal-50 was higher than that of Faisalabad-2008 when exposed to EBL under drought stress. Overall, the EBL plays a major role in the enhancement of growth, biomass, yield, and decrease in oxidative damage in wheat under drought conditions, however; field investigations with different doses of EBL are needed before any further recommendation. This article is protected by copyright. All rights reserved.

中文翻译：

---

24-表油菜素内酯对干旱胁迫下两个小麦品种植物生长、抗氧化防御系统及内源激素的影响

干旱压力是提高农业生产力以满足世界人口粮食需求的主要限制因素。使用各种生化剂对植物施肥以提高小麦的抗旱性，然而，以前的工作在解决问题方面受到限制？这些问题存在于不同生长阶段的植物中。因此，进行了一项温室研究，通过叶面喷施 24-表布拉斯内酯 (EBL) 来改善两个小麦品种（Chakwal-50 和 Faisalabad-2008）的干旱胁迫。很明显，干旱胁迫对小麦植株的生长、光合作用和产量有负面影响。EBL 在最佳和干旱条件下均显着增强了植物生长。EBL 提高了株高、穗长和根干重，与对照相比，芽和谷粒。此外，叶面喷施 EBL 积极增强渗透剂的积累，增加光合色素的量，并改善气体交换参数。EBL 通过减少电解质泄漏、丙二醛和过氧化氢含量来最大限度地减少氧化应激，同时它在干旱胁迫下增强抗氧化酶（如过氧化氢酶、超氧化物歧化酶和过氧化物酶）的活性。EBL显着提高了干旱胁迫下脱落酸、吲哚乙酸、细胞分裂素等胁迫激素水平。在干旱胁迫下暴露于 EBL 时，Chakwal-50 的生长响应高于 Faisalabad-2008。总体而言，EBL 在促进生长、生物量、产量、然而，干旱条件下小麦的氧化损伤减少；在提出进一步建议之前，需要对不同剂量的 EBL 进行现场调查。本文受版权保护。版权所有。