Overexpression of Oshsp16.9 Gene Encoding Small Heat Shock Protein Enhances Tolerance to Abiotic Stresses in Rice

Plants have adapted the ability to respond to various abiotic stresses such as high salinity, osmotic stress, high and low temperatures, and drought in order to survive. Small heat shock proteins (sHsps) play important and extensive roles in plant defenses against abiotic stresses. Herein, we cloned an sHsp gene from the rice, which we named Oshsp16.9 based on the molecular weight of the protein. Real-time PCR analysis showed that expression of the Oshsp16.9 gene was rapidly and strongly induced by stresses including high-salinity (250 mM NaCl), osmotic stress (300 mM mannitol), 100 μM ABA, cold (4°C) and heat (45°C). Subcellular localization assay indicated that Oshsp16.9 was localized specifically in the cytoplasm. In addition, overexpression of Oshsp16.9 in rice conferred tolerance of transgenic plants to salt and drought stress. Taken together, these results suggest that the Oshsp16.9 gene is an important determinant of stress response in plants.