OsKAT2 is the prevailing functional inward rectifier potassium channels in rice guard cell

AtKAT 1 plays roles as a major channel to uptake K⁺ in guard cell when stomata open in dicot model plant Arabidopsis. In a recent publication, we isolated 3 KAT -like potassium channels in rice. We expressed them in CHO cell to identify electrophysiological characteristics of the channels. OsKAT 2 showed much bigger inwardly rectifying potassium channel activities among them. The histochemical X-glu staining of transgenic rice leaf blades expressing β-glucuronidase fused with OsKAT 2 promoter showed that the OsKAT 2 is dominantly expressed in rice guard cell. These findings indicate that OsKAT 2 may be a functional ortholog of AtKAT 1 in rice. Thus this gene will be the prime target for engineering the guard cell movement to improve drought tolerance in monocot plants, including most major crops.