Analysis of the function of OsSUT1 (R188K) in yeast and plants. (A) 14C-sucrose uptake by yeast SEY6210 expressing OsSUT1 wild type, OsSUT1(R188K) mutant, and the empty vector pDR196. Assays were performed at 30°C with 1 mM sucrose in Na phosphate buffer at pH 4.0 or pH 7.0 for 5 minutes. Data are presented as mean ± SE (n=3). (B) 30-day Arabidopsis plants, including the wild type control (SUC2/SUC2), suc2-5 homozygous (suc2/suc2), suc2 homozygous transformed with OsSUT1, and suc2 homozygous transformed with OsSUT1(R188K).