Abstract: 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 translational 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) databases and will be an important experimental model in investigating vegetative desiccation tolerance.