Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/21/2009
Publication Date: 10/11/2009
Citation: Oliver, M.J., Cushman, J.C., Sharp, R.E., Payton, P.R. 2009. Exploiting the Genomes of Dehydration/Desiccation-Tolerant Species in Crop Improvement Strategies. Interdrought III Meeting, October 11-16, 2009, Shanghai, China. 2009 CDROM. Interpretive Summary:
Technical Abstract: An understanding of plant responses to dehydration has important consequences for plant biology in general and direct impacts for agriculture. Over 10% of arable lands are affected by drought, declining average yields for most crops by more than 50%. Thus, improving drought tolerance is a priority area for agricultural research agencies. Understanding how plant cells tolerate water loss, as opposed to how plants limit water loss, is a prerequisite for developing novel strategies for improving drought tolerance. The focus of our work is to combine comparative “omics” and phylogenetics to identify genes and gene networks that are adaptive and central to the tolerance of cellular dehydration. This involves the use of resurrection species as models for dehydration tolerance coupled with a suite of comparative “omic” and functional analyses that allows for the phylogenetic assessment of mechanistic components related to the acquisition and expression of dehydration tolerance. Building on our transcriptomic work with a desiccation tolerant moss (Tortula ruralis) we have extend our phylogentic-based studies into the more complex resurrection plants, Selaginella lepidophylla (a lycophyte) and Sporobolus stapfianus (a grass). By utilizing sister-group contrasts, which compare sensitive to tolerant phenotypes, we are able to discern those responses that are injury related from those that are involved in the tolerance mechanisms. We can also distinguish between water deficit responses (related to water retention mechanisms) from responses related to cellular dehydration, which appear to be distinctly different. Our studies have revealed the importance of maintaining ATP levels during dehydration, new insights into the involvement of sugars in cellular dehydration tolerance, the involvement of signaling pathways in the recovery response, and the value of nitrogen storage during the drying phase. As our “omics” tool-kit becomes better developed, the functional role of individual genes and gene networks will become a major focus of the group. Our initial work in this area has focused on regulatory genes that we suspect activate entire networks of genes and gene products associated with dehydration tolerance in the land plants.