Preliminary Functional Analysis Of Chitinases, CTS1-like Genes In Magnaporthe Oryzae

Chitinase is a kind of glycoside hydrolases, widely exists in various organisms.In the Fungi,chitinase hydrolyzes the cell wall during in cell division so it play animportant role in the fungi cell division and morphogenesis. The research results areshown that disruption of the Saccharomyces cerevisiae CTS1gene encoding thisenzyme led to cell condensation and a defect in cell separation. For understand therole of CTS1genes in pathogenic fungus, we analyze the preliminary function ofCTS1-like gene MGG₁0333.6,MGG₁0876.6,MGG₀3599.6and MGG₀4073.6inMagnaporthe oryzae.First, protein functional domains, subcellular localization and phylogeneticrelationship of CTS1-like genes in Magnaporthe oryzae were analyzed by usingseveral bioinfomatics tools. Moreover, functional analysis of this genes wasconducted by gene knock-out techniques. The results showed that these four mutantshave no significant difference in colony growth rate, conidial germination andappressorium formation compared with wide-type. In penetration assays with onionepidermal cells, there were no difference in the mutants and wide-type andappressorium were able to penetrate and form limited infectious hyphae in onionepidermal cells. Moreover, The results were the same in the plant pathogenicity assays.In comparison with the Saccharomyces cerevisiae CTS1gene, Magnaporthe griseaCTS1-like genes formed multigene family. These four CTS1-like genes deletionrespectively did not affect Morphogenesis and pathogenicity, suggesting thepotential for functional redundancy within protein families. The mechanism needsto be further researched.