Enhances Salt Stress Tolerance in Rice.

High salinity seriously affects crop growth and yield. Abscisic acid-, stress-, and ripening-induced (ASR) proteins play an important role in plant responses to multiple abiotic stresses. In this study, we identified a new salt-induced gene in rice () and functionally characterized its role in mediating salt tolerance. Transcript levels of were upregulated under salinity stress, HO and abscisic acid (ABA) treatments. Nuclear and cytoplasmic localization of the OsASR6 protein were confirmed. Meanwhile, a transactivation activity assay in yeast demonstrated no self-activation ability. Furthermore, transgenic rice plants overexpressing showed enhanced salt and oxidative stress tolerance as a result of reductions in HO, malondialdehyde (MDA), Na/K and relative electrolyte leakage. In contrast, RNAi transgenic lines showed opposite results. A higher ABA content was also measured in the overexpressing lines compared with the control. Moreover, OsNCED1, a key enzyme of ABA biosynthesis, was found to interact with OsASR6. Collectively, these results suggest that OsASR6 serves primarily as a functional protein, enhancing tolerance to salt stress, representing a candidate gene for genetic manipulation of new salinity-resistant lines in rice.