Zhang Ming, Lu Yun, Wang Xiao-Feng
College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China.
Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao. 2007 Feb;33(1):9-17.
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.
一些耐旱植物即使在含水量低至0.3克水/克干重时仍能在水分流失的情况下存活,并且当它们再次获得足够的水分时,仍能迅速修复因脱水造成的细胞结构和功能损伤。在适度脱水时,组织会积累一些特殊的蛋白质、小分子、碳水化合物等,这些物质可以通过自身的特性保护大分子和膜的原始结构和功能。同时,水分流失会导致活性氧清除酶(超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶)的活性增加。为了获得耐旱性,植物或种子中的水必须被诱导进入玻璃态,这种变化可以由许多化合物诱导。关键的保护手段还包括增加内源性抗氧化剂的形成以及两亲性物质在脂质相中的分配以保护膜。复苏植物和种子是耐旱性研究的良好材料。