Down-regulation of OsRACK1 by Anti-sense Approach Results in Drought Tolerance Enhancement in Rice (Oryza sativa)

RACK1 is a scaffold protein with versatile functions and plays important roles in the regulation of plant growth and development. Transgenic rice (Oryza sativa), with the expression of OsRACK1 anti-sense construct, was used to study possible functions of OsRACK1 in response of rice to drought stress. Real-time PCR analysis showed that the expression of OsRACK1 in transgenic rice plants was reduced by more than 50%. The tolerance to drought stress was stronger in transgenic than in non-transgenic rice plants. The epioxidation of membrane and production of malonaldehyde were significantly lower and the superoxide dismutase (SOD) activity was significantly higher in transgenic plants than in non-transgenic plants. OsRACK1 may negatively regulates tolerance of rice to drought stress, which is associated with the redox system in rice.