[Identification of genes related to resistance to Magnaporthe grisea using differential display technique in rice]

Rice blast caused by Magnaporthe grisea is one of the most serious constraints on high productivity. Understanding the mechanism of the infection of Magnaporthe grisea and the change of gene expression after infection is useful to control blast disease in rice. This work presents the isolation of differentially expressed cDNA fragments from rice leaf induced by the inoculum suspension of Magnaporthe grisea using mRNA differential display technique. Total 87 differential expressed cDNA fragments were recoveried and reamplified. The dot-blotting results showed that 6 fragments of 81 were confirmed to be the expression induced by Magnaporthe grisea inoculum. Those fragments were then cloned into vectors for sequencing. Sequence analysis through Internet Blast searching showed that 3 fragments were novel gene fragments. One was homologous with a putative malate synthase gene on rice chromosome 4 with 78% identities of amino acid; one was highly homologous (75% identity) with rice RPR1 gene on chromosome 11, which has a conservative structure of NBS-LRR domain and may be related to signal transduction of rice defense reaction;another one was homologous with a putative thioredoxin gene on rice chromosome 6 with the identity of 72%.