脱水导致的胞内溶质变化与植物耐干性的获得

植物耐干性是指许多植物个体和部分植物种子能在含水量极低的条件下存活,在回水的过程中迅速启动修复机制,细胞经重新水合修复所受损伤的能力。在脱水过程中,植物会合成和积累某些小分子物质、碳水化合物和特殊的蛋白质;在极度脱水状态下,多组分参与的玻璃化的形成和两性物质的重新分配、耐干性植物中特有的抗氧化机制都是植物获得耐干性的重要条件。复苏植物(resurrection plant)和部分被子植物种子是当前研究植物耐干性的模式材料。

Dehydration-induced Intracellular Solute Changes and Acquisition of Plant Desiccation Tolerance

Some desiccation-tolerant plants can survive the loss of water even when the water content becomes as low as 0.3 g H2O/g dry weight, and can still repair quickly their cellular structures and function damages by desiccation when they get access to enough moisture again. While moderate dehydration, the tissue could accumulate some special proteins, small molecules, carbohydrate etc. which can protect the original structure and function of macromolecule and membrane through themselves' natural characteristics. Mean-while, water loss results in increased activities of reactive-oxygen-scavenging enzymes (SOD, CAT, APX and GR). For the acquisition of desiccation tolerance, water in the plants or seeds must be induced to enter the glassy state, a change which can be induced by many compounds. The crucial protective means also include the increased formation of endogenous antioxidants and the partitioning of amphiphilic substances in the lipid phase to protect the membrane. The resurrection plants and seeds are good materials for desiccation tolerance research.