Functional Analysis Of Chitinase Gene In Magnaporthe Oryzae

Chitinases are digestive enzymes that break down glycosidic bonds in chitin. In fungi, chitinase is shown to be involved in the regulation of cell wall degradation, spore germination, tip growth, hyphal branch, spore detachment and hyphal autolysis. In our previous study, a putative chitinases gene MGG₀8054.6 knock-out mutants showed decreased pathogenicity to rice and barley in Magnaporthe oryzae, we therefore studied their functions of 3 genes encoding glycosyl hydrolases family 18.First, protein domains, properties and their phylogenetic relationship of all members in glycosyl hydrolases family 18 in Magnaporthe oryzae were analyzed by using several bioinfomatics tools. Their gene expression profile at different growth stages was detected by real-time quantitative PCR.Second, functional analysis of three genes MGG₀0086.6, MGG₀7927.6, MGG₀1247.6 in Magnaporthe oryzae was conducted by gene knock-out techniques. The phenotype analysis showed that these gene knock-out mutants had no effects on olony growth, conidial development, conidial septum compared with the wild type. There is no difference neither when inoculating these mutants on onion epidermis, barley leaves and rice leaves.Taking together, the morphogenesis and pathogenicity of genes MGG₀0086.6, MGG₀7927.6 and MGG₀1247.6 mutants were not affected by gene knock-out. Since chitinases of glycosyl hydrolases family 18 in Magnaporthe oryzae form a superfamily, our results may suggest there are redundant effects among members in the superfamily. however, the mechanism under which needs to further study.