Submitted to: Annual International Meeting for Moss Research
Publication Type: Abstract Only
Publication Acceptance Date: May 16, 2005
Publication Date: July 25, 2005
Citation: Oliver, M.J., Payton, P.R. 2005. Evolutionary linkage between drought and vegetative desiccation tolerance in plants: Moss as a basal comparison[abstract]. Annual International Meeting for Moss Research. Paper No. T13. Technical Abstract: Drought tolerance and desiccation tolerance have often been cited as manifestations of the same mechanism: desiccation tolerance being the extreme form of drought tolerance. However, there is a fundamental difference between drought and desiccation tolerance; drought tolerance mechanisms include ways of maintaining cell water content, such as osmotic regulation and stomatal closure, whereas desiccation tolerance consists of ways to survive the complete loss of water. It is clear that an evolutionary understanding of the relationship between drought and desiccation tolerance is necessary to determine which genes are adaptive in nature and which simply respond to secondary events such as cell injury. Our approach is to compare the expression profiles for genes in response to water deficits in drought sensitive species with their orthologues in desiccation-tolerant species during desiccation and within a phylogenetic framework. Our comparisons encompass a dicot to dicot pairing, a monocot to monocot pairing, and the comparison of both to the most primitive form of vegetative desiccation tolerance as manifested in the desiccation tolerant bryophyte Tortula ruralis. Initial comparisons between the water stress response of Arabidopsis and the desiccation response of Tortula have generated a solid baseline of similarities and differences that have generated the necessary hypotheses for our pair-wise comparisons. These data will allow us to focus attention on genes and gene networks that are truly central to cellular dehydration tolerance and may enable a more rational approach for the improvement of drought tolerance in crop species.