Abstract
Stomata in the epidermis regulate gas exchange between plants and atmosphere. Stomatal opening, which is mediated by blue-light receptor phototropins, is driven by activation of the plasma membrane H+-ATPase. Under drought stress, a phytohormone abscisic acid (ABA) induces stomatal closure to prevent water loss from plants. However, the signaling pathways for blue light-induced stomatal opening and ABA-induced stomatal closure have yet to be determined. Here, we performed the mutant screening focused on stomatal aperture-dependent transpiration in detached leaves from EMS-treated Arabidopsis thaliana and isolated ftd (fast transpiration in detached leaves) mutants. Of these, ftd2 showed dwarf and pale green phenotypes in addition to open-stomata phenotype with ABA-sensitivity in stomatal guard cells. Rough mapping analysis revealed that FTD2 locus locates on the 5th chromosome. We will report the results of fine mapping.
