Functional Analysis Of Rice OsCIPK10 Gene In Stress Tolerance

Calcium is a ubiquitous secondary messenger in plants and plays crucial roles in plant growth, and development and responses to internal and external stimulation. The spatial.and temporal Ca2+ signal can be caused by the different stresses, and decoded by many Ca2+ -sensors which will activate the phosphorylation cascades in downstream and the expression of stress-related genes. The CBL-interacting protein kinase (CIPKs) belongs to the serine/threonine class of kinases with a high conserved SNF kinase domain and a NAF motif. CBLs and CIPKs are interact in complicated network, and CBL-CIPK is considered having an important function in the stress-signaling pathways of plant cell. The researches of CIPK in rice will help to understand the mechanism of CBL-CIPK signaling network under stresses in plants. Previous studies have found that, the gene expression of OsCIPK10 were various in different tissues (leaf and root), and stresses including salt, low K+, ABA, Hg2+, cold and Xanthomonas oryzae pv. oryzae was induced by all kinds of stresses. These genes may be upstream regulators in these pathways and participate in the pathways of multi-stress resistance. To investigate the cellular function of rice OsCIPK10 gene, we constructed OsCIPK10 gene overexpression and RNAi inhibit expression vector, transformated into rice calli by agrobacterium-mediated co-transformation, After hygromycin selection and regeneration, Received 80 regenerated rice lines. PCR identification proved that the vector was integrated into the genomes of the rice plants. Semi-quantitative RT-PCR analysis on the T1 generation of transgenic lines showed that the expression of OsCIPK10 extremely increased in overexpression transgenic plants, and decreased to some extent in inhibiton transgenicones. By evalution of tolerance to 150mmol NaCl, drought and low temperature (4℃) treatments, OsCIPK10 overexpression transgenic plants can increase drought tolerance, and RNAi OsCIPK10 transgenic plants might enhance the salt tolerance. It means that OsCIPK10 gene may be involved in the response of rice salt or drought-tolerant approach, this result remain needs to be proved.