McKenzie, Jonathan , Luesse, Darron , Wyatt, Sarah .
Colocalization of GPS2 and PIN proteins to demonstrate their role in the signal transduction in gravitropism.
The ability of a plant to respond to a gravity vector is vital for optimal organ positioning, nutrient uptake, and metabolism. The process of gravitropism can be simplified into three basic stages: perception, signal transduction, and response. Near the end of the signal transduction phase, a differential auxin gradient is established with more auxin being distributed to the lower side of the plant stem, stimulating differential cell elongation and resulting in organ curvature. To study signal transduction, Arabidopsis plants can be gravistimulated under cold conditions that inhibit auxin transport. Wild type plants bend normally when returned to room temperature, but the gravity persistent signal (gps2) mutants bend the opposite direction, indicating a defect upstream of auxin transport. GPS2 is a vesicle-associated membrane protein responsible for vesicle docking. In gps2 mutants, lateral auxin transport is reversed, with more auxin distributed to the upper side of the stem, suggesting a connection between PIN-FORMED (PIN) proteins and GPS2. PIN genes encode a family of proteins involved in the exportation of auxin from one cell to another, and their possible mis-localization could be responsible for the altered auxin distribution in gps2. Sequences that code for PIN1, PIN2, and PIN3 and their endogenous promoters were each fused with the sequence for the fluorescent protein DsRed-monomer. Ultimately, to elucidate the spatial and temporal relationship of the PINs and GPS2, the PIN constructs will be co-expressed in Arabidopsis with a GPS2::GFP fusion and will be examined using confocal microscopy.
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1 - Ohio University, Department of Environmental and Plant Biology, 317 Porter Hall, Athens, OH, 45701, US
2 - Ohio University, Department of Environmental and Plant Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM