硅提高植物抗旱性的生理机制研究进展

Research Progress on Physiological Mechanism of Silicon on Enhancing Plant Drought Resistance

摘要:

干旱作为限制作物产量和品质的主要非生物胁迫之一，对全球社会、经济和生态造成巨大损失。在全球气候变化背景下，提高植物抗旱性的重要性日益突显。硅能够提高植物的抗旱性：外源硅的施用可以影响气孔导度，改变蒸腾速率，改善植物水分状况；通过调节气孔动力学、合成光合色素，促进光化学反应，从而改善光合作用；此外硅可通过渗透调节以平衡植物对矿质元素的吸收，以及调节抗氧化防御系统，减轻植物在干旱胁迫中的氧化损伤。总结了硅对干旱胁迫下植物水分利用、光合作用、矿质元素吸收、抗氧化系统、植物激素代谢等方面的作用及相关生理机制。建议未来从复合逆境胁迫、低硅积累植物等方面进一步揭示硅提高植物抗旱性的作用机制，从而为农林生态系统合理利用硅素来提高生产效率提供科学依据和理论基础。

Abstract:

In the context of global climate change, drought has become one of the major abiotic stresses limiting crop yield and quality worldwide, which causes huge losses to the global society, economy and ecology. Hence, it is increasingly critical to enhance the drought resistance of plants. Numerous studies at domestic and abroad have confirmed that silicon can promote plant drought resistance. For example, the application of exogenous silicon can improve water status of plants by affecting the stomatal conductance and changing the transpiration rate; silicon can also improve photosynthesis by regulating stomatal dynamics, synthesizing photosynthetic pigments and promoting photochemical reactions; in addition, silicon can not only balance the absorption and utilization of minerals by plants through osmotic adjustment but also regulate the antioxidant defense system to reduce the oxidative damage of plants under drought stress. Here, we systematically summarize the effects of silicon on plant water utilization, photosynthesis, mineral absorption, antioxidant systems, plant hormone metabolism and related physiological mechanisms under drought stress. It was suggested that the mechanism by which silicon enhances drought resistance of plants should be revealed from the aspects of combined stress and low silicon accumulating plants in the future, so as to provide a scientific basis and lay a theoretical foundation for the rational use of silicon in agroforestry ecosystems to improve production efficiency.