Integrative Plant Physiology
Daniel, Janet , Hupalo, Daniel , Ruck, Kate , McAdams, Julia , Souther, Stephanie .
Characterization of the role of STP1 in seed germination and root growth in Arabidopsis thaliana.
STP1 is a high affinity monosaccharide/proton symporter which transports the monosaccharides glucose and galactose. STP1 belongs to a family of at least 14 highly homologous monosaccharide transporters predominantly localized to plasma membranes of sink tissues. STPs play roles in pollen development and maturation and are regulated by wounding and pathogen attack. In germinating seed and seedlings, STP1 mRNA expression peaks at 2 days and declines slowly over the next 5 days. To understand the role that STP1 plays in the regulation of osmotic balance in the growing plant, we studied the response of an STP1 T-DNA knockout mutant of Arabidopsis thaliana to exogenous osmolytes. Seed germination rates and root growth of seven-day seedlings that were grown on 0.5X MS salts solid media supplemented with various sugars and sodium chloride were analyzed. Our initial findings support previous observations that plants deficient in STP1 show no obvious morphological malformations during germination and seedling growth, as well as insensitivity to galactose. We report that the average root length of STP1 knockout 7-day old seedlings was significantly shorter than wildtype when grown on media supplemented with either sucrose or fructose. We also found that, compared to wildtype, STP1 knockout seeds had lower germination rates when grown on media supplemented with 50-150mM NaCl. Taken together, these results suggest that the absence of STP1 alters the germination and growth of seedlings in response to external osmolytes.
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1 - James Madison University, Biology, Burruss Hall, MSC 7801, Harrisonburg, VA, 22807, USA
2 - James Madison University, Biology
seedling growth and development.
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM