Founction Analysis Of Stress-activated Protein Kinase OsSAPK2 Involved In Disease Resistance In Rice

Rice sucrose nonfermenting1-related protein kinase2(SnRK2),which is also known as stress-activated protein kinases(OsSAPKs),plays an important role in signal transduction of abiotic stress,but their role in biotic stress is still unclear.In this study OsSAPK2(LOC_Os07g42940),a member of SnRK2 family,was used for further analysis.We analyzed the amino sequence and constructed the phylogenetic tree genetic analysis;We constructed the GFP vector for subcellular location and used yeast two-hybrid technology to screen and analyze the interact protein;We choose the specific sequence of the cDNA as the RNAi targer fragment,and construct the RNAi vectors.Transform to the9804 and get the transgenic rice plant,and identification the resistance of the transgenic plant.Analyze the expression of disease-related gene and the candidate interacting protein gene.The main results are as follows:1: OsSAPK2 is one member of Kulik's II group like OsSAPK1,OsSAPK3,contains a special domain STYKC and located in nucleus and cytoplasm,may involved in the signal transduction and metabolism both of cell nucleus and the cytoplasm.There ere multiple cis acting element related with disease resistance in the promoter speculate that OsSAPK2 may participate in regulating plant biological signal pathway.2: Compared with non-transgenic plants,transgenic plants were more susceptible to Xoo infection.The expression level and lesion length after inoculation different bacterial have obvious different may due to the different types of the OsSAPK2 in response to different race of leaf blight or the exist of genetic redundancy.It may also due to the interaction with the R gene of the plant.3: OsSAPK2 and disease-resistant genes OsLRR1,OsHIR1 were down regulated in OsSAPK2-RNAi transgenic rice,while disease-related gene OsMAPK5 was up regulated,indicate that OsSAPK2 may regulate the resistance by control more than one disease-related genes and is a positive regulater of rice bacterial leaf blight resistance.4: In addition,OsSAPK2 can activate itself and may interact with some other function proteins such as OsEREBP1 which expression have significant differences between OsSAPK2-RNAi transgenic rice and 9804.It may caused by OsSAPK2 gene was knockoutted in OsSAPK2-RNAi transgenic plants.The results provide information and theoretical reference for the further study on the molecular mechanism and signaling pathways of OsSAPK2 regulation of bacterial blight.