See more from this Session: Global Agronomy Graduate Student Poster Competition
Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level
Increased climate variability is affecting crop yield and quality. Ameliorating this predicament will require an investigation of how plants respond to stresses such as a reduced supply of water. Using 10-day-old wheat seedlings, we withheld irrigation for 3 to 9 d. Their performance was then compared with untreated control plants (standard watering schedule). At each sample point, proteins were extracted from the chloroplasts, separated by two-dimensional electrophoresis (2-DE), and stained with Coomassie brilliant blue. During short-term water stress, rates of photosynthesis and transpiration, stomatal conductance, and relative water content decreased while the proline content increased. Through 2-DE, we detected 20 differentially expressed proteins from the chloroplasts and analyzed them with high through-put MALDI-TOF/TOF-MS. Under these stress conditions, 9 proteins were up-regulated in their protein abundance while the levels of 11 proteins were unevenly affected. Levels of the Rubisco small and large subunits, plasma membrane proteins in the chloride carrier/channel family, and H+-transporting two-sector ATPase were up-regulated by this treatment whereas other plasma membrane proteins, e.g., membrane-bound ATP synthase subunit b, were down-regulated by drought. Single-pass transmembrane domain such as the cytochrome b6-f complex declined in abundance under water stress. These results suggest that members of the chloride carrier/channel family as well as H+-transporting two-sector ATPase are target proteins that are induced by water stress in wheat chloroplasts.