苔藓植物耐旱机制研究进展

耐旱藓类快速脱水并存活的能力可由快速建立起来的对环境变化的耐受机制来反映,保护细胞完整性的组成型机制与修复细胞损伤的诱导机制协同作用使苔藓植物渡过干旱胁迫.再水化时光合系统原初恢复非常迅速;ABA处理可显著改变PSⅡ的生理特征;基因表达的变化主要由翻译调控引起;脱水组织中贮存mRNPs既保护了mRNAs,又加快了再水化修复速度.山墙藓(Tortula ruralis)是耐旱研究较多的一个种,已建立了表达序列文库(EST),将会成为耐旱研究的重要模式植物.

Advances in the Desiccation Tolerance of Mosses

Mosses can survive rapid desiccation by a constructive mechanism response to the surrounding environment. Desiccation tolerance is a balance between two fundamental components: the protection of cellular integrity and the repair of desiccation- and rehydration-induced cellular damage. Abscisic acid (ABA) treatment increases the physiological properties of photosystem II in mosses. The alteration in gene expression associated with rehydration is mediated mainly by an alteration in translational controls at the level of differential selection and/or recruitment by transla- tional machinery from a qualitatively constant mRNA pool. The formation of mRNPs in response to water loss and their possible roles in mRNA storage and protection have important consequences for study of vegetative desiccation tolerance and stress responses of plants in general. Tortula ruralis is the most studied desiccation-tolerant species in established expressed sequence tag (EST) data- bases and will be an important experimental model in investigating vegetative desiccation tolerance.