|Alexander, Danny -|
Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2009
Publication Date: July 18, 2009
Citation: Oliver, M.J., Alexander, D. 2009. A Comparative Metabolite Profile Assessment of Dehydration Tolerance Strategies in Two Species of Sporobolus: The Desiccation Tolerant S. Stapfianus and the Desiccation Sensitive S. Pyrimidalis. American Society of Plant Biologists Annual Meeting, July 18-22, 2009, Honolulu, Hawaii. 2009 CDROM. Technical Abstract: An understanding of plant responses to dehydration has important consequences for plant biology in general and directly 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 is a vital prerequisite for developing strategies for improving drought tolerance. We used the desiccation tolerant grass Sporobolus stapfianus and the desiccation sensitive S. pyrimidalis to form a sister-group contrast to reveal adaptive metabolic responses to dehydration. Leaf extracts from plants at various stages of dehydration for both species were analyzed using three independent platforms, LC-MS/MS (+ESI), LC-MS/MS (-ESI), and GC-MS. The design and statistical analysis of the data allowed for a robust assessment of the levels of 167 individual metabolites. Significant changes in metabolite levels did not occur in S. pyrimidalis in response to severe water deficit. S. stapfianus,however, exhibits significant increases in anti-oxidant related compounds, amino acids, and sugars. The most significant are the gamma-glutamyl peptides that presumably serve an anti-oxidant role within the cell. The accumulation of amino acids occurs during the later stages of drying indicating that they may play a role in nitrogen storage during desiccation. The accumulation of sugars during drying is not unexpected, however, the fact that tri- and tetrasaccharides exhibit the largest increase is unusual in desiccation tolerant plants. These studies help to form a framework for further functional studies into the mechanisms of dehydration tolerance in plants.