Abstract
In order to find the genes involved in salt tolerance of rice, we carried out the screening of a rice full-length cDNA expression library through functional complementation in yeast. The yeast expression library was constructed using Gateway System (Invitrogen) from the rice full-length cDNA library of NIAS that contains about 28,000 clones. The library was transformed in salt-sensitive yeast strain G19 (Δena1-4) and the transformants were selected on SD plate containing 0.5 M of NaCl. In the screening, a cDNA clone encoding a homologue of the Arabidopsis potassium channel protein KAT1 (OsKAT1) suppressed the salt-sensitive phenotype of G19. The transformants accumulated lesser amounts of Na+ than mutant cells under 0.5 M NaCl condition, whereas the K+ amount of these cells were almost the same. These results suggest that OsKAT1 may be participated in maintenance of cytosolic ion homeostasis during salt stress.
