棉花盐害与耐盐性的生理和分子机理研究进展

Physiological and Molecular Mechanisms of Salt Injury and Salt Tolerance in Cotton

盐胁迫通过离子毒害、营养失衡和渗透胁迫,引起棉株体生理生化代谢失调,进而影响棉花的生长发育和产量、品质。但棉株体可以通过膜脂过氧化清除系统活性的提高维持质膜的相对稳定,通过合成和积累脯氨酸、葡萄糖和氨基酸等小分子有机物质缓解渗透胁迫,通过调节盐离子在不同器官、组织或细胞内的区域(隔)化分布减轻离子毒害,而表现出较强的耐盐性。Na+/H+反向转运蛋白和LEA蛋白(晚期胚胎发生富集蛋白)等的合成及其相关基因的表达可能参与甚至调控了棉株体防御或忍耐盐胁迫的过程。

Salinity is a big threat to cotton production. Salt stress leads to a series of physiological and biochemical decompensation in cotton plants through osmotic effects （dehydration）, nutritional imbalance and toxicity of salt ions （Na^- and Cl）, and finally results in depressed plant growth, lint yield and quality. However, cotton plants usually exhibit a relatively high tolerance to salt stress via several mechanisms that include protection of cytoplasmic membrance from oxidative damage by salt-induced higher levels of antioxidants, salt-inhanced synthesis of organic solutes like proline, glucose, amino acid to mantain water potential, and efficient ion compartmentation and redistribution in organs, tissues or within a cell. Genes encoding proteins like LEA （late embryogenesis abundance） protein and Na^-/H^＋ antiporter, might be involved in the defence system.