Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 8, 2001
Publication Date: N/A
Technical Abstract: Desiccation-tolerance in plants can be exhibited in a variety of tissues both propagative and vegetative. Vegetative tolerance to desiccation, although rare, occurs in species that represent most major classes of plants, the majority, however, are found in the phylogenetically basal taxons that constitute the bryophytes, algae and lichens. It has been suggested that plants employ mechanisms of desiccation-tolerance that follow two basic scenarios, cellular protection and cellular repair, and that most plants employ aspects of both but to differing degrees. Many of the desiccation tolerant members of the phylogenetically basal taxons, including the bryophyte Tortula ruralis, appear to employ a tolerance mechanism comprised of a constitutive cellular protection component, combined with genes whose expression increases upon rehydration (rehydrins). The rehydrins are presumably directed primarily towards the repair of damage incurred during the drying and/or rehydration processes. Using a collection of plant DNA samples from desiccation tolerant and related species, we have cloned and sequenced sections of several orthologs of the rehydrin, Tr288, and replacement histone genes (rhis3). These sequence data were used to explore the evolutionary history of the cellular repair component of desiccation tolerance.