College of Enology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
School of Food Science and Technology, Shihezi University, Shihezi, 832061, Xinjiang, China.
Plant Cell Rep. 2024 Aug 19;43(9):219. doi: 10.1007/s00299-024-03283-y.
Exogenous application of 24-epibrassinolide can alleviate oxidative damage, improve photosynthetic capacity, and regulate carbon and nitrogen assimilation, thus improving the tolerance of grapevine (Vitis vinifera L.) to drought stress. Brassinosteroids (BRs) are a group of plant steroid hormones in plants and are involved in regulating plant tolerance to drought stress. This study aimed to investigate the regulation effects of BRs on the carbon and nitrogen metabolism in grapevine under drought stress. The results indicated that drought stress led to the accumulation of superoxide radicals and hydrogen peroxide and an increase in lipid peroxidation. A reduction in oxidative damage was observed in EBR-pretreated plants, which was probably due to the improved antioxidant concentration. Moreover, exogenous EBR improved the photosynthetic capacity and sucrose phosphate synthase activity, and decreased the sucrose synthase, acid invertase, and neutral invertase, resulting in improved sucrose (190%) and starch (17%) concentrations. Furthermore, EBR pretreatment strengthened nitrate reduction and ammonium assimilation. A 57% increase in nitrate reductase activity and a 13% increase in glutamine synthetase activity were observed in EBR pretreated grapevines. Meanwhile, EBR pretreated plants accumulated a greater amount of proline, which contributed to osmotic adjustment and ROS scavenging. In summary, exogenous EBR enhanced drought tolerance in grapevines by alleviating oxidative damage and regulating carbon and nitrogen metabolism.
外源施用 24-表油菜素内酯可以减轻氧化损伤，提高光合作用能力，并调节碳氮同化，从而提高葡萄(Vitis vinifera L.)对干旱胁迫的耐受性。油菜素内酯(BRs)是植物中的一组植物甾体激素，参与调节植物对干旱胁迫的耐受性。本研究旨在探讨 BRs 对干旱胁迫下葡萄碳氮代谢的调节作用。结果表明，干旱胁迫导致超氧自由基和过氧化氢的积累以及脂质过氧化的增加。在 EBR 预处理的植物中观察到氧化损伤的减少，这可能是由于抗氧化剂浓度的提高。此外，外源 EBR 提高了光合作用能力和蔗糖磷酸合酶活性，降低了蔗糖合酶、酸性转化酶和中性转化酶，从而提高了蔗糖(190%)和淀粉(17%)的浓度。此外，EBR 预处理增强了硝酸盐还原和铵同化。EBR 预处理的葡萄中硝酸还原酶活性增加了 57%，谷氨酰胺合成酶活性增加了 13%。同时，EBR 预处理的植物积累了更多的脯氨酸，有助于渗透调节和 ROS 清除。总之，外源 EBR 通过减轻氧化损伤和调节碳氮代谢来增强葡萄的耐旱性。
