Developmental regulation and effect of glucose on OsSUT2 promoter activity. a GUS activity was quantitatively analyzed in the embryos from germinating seeds of transgenic rice carrying the OsSUT2 promoter::GUS construct. b GUS activity was determined in isolated embryos cultured in medium with or without glucose. MU 4-methylumbelliferone. The data are presented as mean ± SD, and statistical significance is set at p < 0.05 (asterisk).