GRAS transcription factors are proteins that play diverse roles in plant development. However, the functions of some GRAS genes identified in rice are unknown, especially those related to rice drought resistance. Lijun Luo of the Huazhong Agricultural University in China isolated a novel GRAS transcription factor gene from rice, OsGRAS23.

The expression of OsGRAS23 was found to be induced by drought, salt, and jasmonic acid treatments. OsGRAS23-overexpressing rice plants showed improved drought resistance and oxidative stress tolerance as well as less hydrogen peroxide accumulation than wild-type plants. Further analysis showed that several anti-oxidation related genes were also up-regulated in the OsGRAS23-overexpressing rice plants.

Results demonstrate that OsGRAS23 encodes a stress-responsive GRAS transcription factor that positively modulates rice drought tolerance via the induction of a number of stress-responsive genes.

For more information on the study, read the full article on BMC Plant Biology.

Fig. 3. Molecular identification of OsGRAS23-overexpressing transgenic lines. A Schematic diagram of overexpression construct. LB, left border; HPT, hygromycin phosphotransferase; P_CaMV35S, cauliflower mosaic virus 35S promoter; T_NOS, nopaline synthase gene terminator; and RB, right border. B Relative expression levels of OsGRAS23 in transgenic rice lines. WT: wild type, OE1-OE58: transgenic lines. The gene expression level was analyzed by quantitative real-time PCR. The data represent the mean ± SE (n = 3). C Phenotypes of transgenic rice plants and WT plants grown in PVC pipes