Muse, Tom , Orlov, Lev , Lapchyk, Ludmila , Kachroo, Aardra , Kachroo, Pradeep .
Role of glycerol-3-phosphate dehydrogenase in plant defense signaling.
Glycerol-3-phosphate (G3P) derived from glycerol metabolism, is an essential precursor of all glycerolipid biosynthesis. In plants, G3P is produced either by the G3P dehydrogenase (G3Pdh) catalyzed reduction of dihydroxyacetone phosphate (DHAP), or via the glycerokinase catalyzed phosphorylation of glycerol. The Arabidopsis genome encodes several isoforms of G3Pdh likely targeted to different subcellular locations including, cytosol, mitochondria, and plastids. A mutation in the GLY1-encoded G3Pdh results in reduced carbon flux through the prokaryotic pathway, which leads to a reduction in the hexadecatrienoic acid (16:3) levels. Interestingly, a mutation in gly1 affects the plantís ability to induce systemic acquired resistance, a very important mode of resistance in plants (Nandi et al., 2004). The Gly1 gene also participates in the fatty acid-mediated defense pathway of Arabidopsis. A mutation in gly1 restores altered defense responses associated with reduced 18:1 levels (Kachroo et al., 2004).
To further characterize the role of the GLY1 derived G3P in plant defense, we have initiated a screen for second-site mutations in the gly1 background. Plants obtained from the EMS mutagenized gly1 seeds were characterized for their fatty acid (FA) profiles. Analysis of FA content of over 10,000 plants has yielded 10 plants carrying wild type like levels of 16:3. Genotypic analysis of these plants confirmed presence of the gly1 mutation. Putative gly1 suppressors will be further analyzed for FA content in subsequent generations. True suppressors will eventually be evaluated for their abilities to respond to pathogen infection. Mutations affecting defense responses will eventually be identified using map-based cloning.
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1 - University of Kentucky, Plant Pathology, 201F Plant Science Bldg, 1405 Veterans drive, Lexington, KY, 40546, USA
2 - University of Kentucky, Plant Pathology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM