Cloning And Preliminary Functional Characterization Of Rice Blast Resistance Gene Pi-hk1in Heikezijing

Rice blast caused by Magnaporthe oryzae is one of the most devastating rice diseases worldwide. The use of resistance (R) genes is considered to be the most economical, effective and environmental friendly strategy for blast control. Therefore, carry out new rice blast resistance genes research on the identification and breeding for disease resistance has important practical significance. In our previous research, we found that a japonica landrace rice Heikezijing collected from Taihu Lake region of China exhibited broad-spectrum resistance to at least300isolates collected from China and Japan. The new blast resistance gene Pi-hkl has been fine mapped and physical mapped. In order to identify candidate genes of the Pi-hkl, studies were carried out as follows:1. Gene prediction and annotation was conducted in the45kb interval by the gene prediction systems. The results showed that4genes served as the candidate genes of the Pi-hkl. Expression pattern of these candidate genes was investigated by realt-ime PCR, and the results showed that one candidate gene did not express, which may be pseudo genes. The other three genes P13, P15and P16expressed constructively, and were induced by rice blast.2. The three candidate genes were amplified from the genomic DNA or cDNA by long-range PCR, and the over-expression vector of three candidate genes were constructed. Besides,3genomic sequence fragments of P15, P16, P15and P16were introduced to vectors. The combinants were transformed into the highly susceptible cultivar Suyunuo through Agrobacterium-mediated transformation.3. The blast resistance of transgenic plants was confirmed by artificial inoculation of blast fungus. The results showed that T2transgenic individuals over-expressing P13and T1transgenic individuals over-expressing P15showed slightly increased blast resistance, while the To individuals over-expressing P15showed significantly enhanced resistance to blast. Also, co-transform of P15and P16increased resistance significantly in our expriment.