Abstract
Phototropins act as blue light receptors for phototropism, chloroplast relocation, stomatal opening and leaf expansion. In the blue light-induced stomatal opening, blue light signal perceived by phototropins induces activation of the plasma membrane H+-ATPase through the phosphorylation of the C-terminus with subsequent binding of the 14-3-3 protein and stomatal opening. However, signaling pathway between phots and H+-ATPase is largely unknown. In this study, we performed the screening to isolate the suppressor mutants for closed stomata phenotype in phot1 phot2 double mutant in Arabidopsis. One of the isolated mutants, named scs1 (suppressor mutant for closed stomata phenotype in phot1 phot2), showed open stomata phenotype, but this mutant was sensitive to abscisic acid. Interestingly, the H+-ATPase in guard cells of scs1 showed constitutively high activity state, therefore, this mutant is likely to show the opened stomata phenotype. Now, we are trying to identify SCS1 locus by map-based cloning.
