Poster: Temperature responses

Abs # 143: Distribution and relative amounts of chloroplast protein synthesis elongation factor (EF-Tu) in granal and non-granal chloroplasts in maize

Presenter:	Rahn, Christopher , crahn@usd.edu
Authors	Ristic, Zoran  (A)   Rahn, Christopher  (A)
Affiliations:	(A): The University of South Dakota

Chloroplast protein synthesis elongation factor, EF-Tu, is a protein (45 – 46 kD) that is involved in the elongation of polypeptides during the translational process. In maize, chloroplast EF-Tu has been implicated in heat tolerance, and the recent study of Momcilovic and Ristic [Plant Sci. (2004) 166: 81-88] has indicated that there may be an unequal distribution of this protein between non-granal and granal chloroplasts. This study was undertaken to further investigate this possibility. We separated bundle sheath strands from the rest of the leaf tissue, and we extracted proteins from each group of cells. The purity of each cell preparation was checked by probing for phosphoenolpyruvate carboxylase (PEPC), which accumulates in mesophyll cells, and for Rubisco, which accumulates in bundle sheath cells. We are currently investigating the relative amounts of chloroplast EF-Tu using anti-EF-Tu antibody and western blotting. The results of this analysis will be presented and discussed.