Function Research Of BC1G₀8931in Botrytis Cinerea

Gray mold caused by Botrytis cinerea is a worldwide distribution plant disease, and B.cinerea has a very wide host range and causes serious economic losses. Control of gray mold mainly depends on fungicides. Exploring the mechanism of the pathogenicity or development of B.cinerea at the molecular level can lay a basis for the control of B.cinerea. The gene funtion of the BC1G₀8931was analyzed preliminarily using gene silencing and overexpression technology in this study, the main results were listed as following:1. BC1G₀8931was the homologous of SSIG₁1468, which was screened from the gene expression profile of Sclerotinia sclerotiorum. The ORF of BC1G₀8931was829bp in length, containing two exons and one intron. Its cDNA sequence was741bp, encoded a246aa protein. This protein had a signal peptide and two conserved domains, DUF3129and DUF3988, with unknown function. RT-PCR results showed that the expression level of BC1G₀8931was high at the mycelial growth stage, while was low at the sclerotia formation stage.2. Overexpression and silencing vector of BC1G₀8931were constructed, and then transformed to B. cinerea strains CanBC-3V by ATMT technology.147silencing and89overexpression transformants were obtained. These transformants were confirmed by PCR detection of the hygromycin resistance gene fragment. The RT-PCR results showed that the expression of BC1G₀8931in most transformants was changed in different degrees. Expression of BC1G₀8931in five transformants （three silencing transformants and two overexpression tansformants） was verified by Real-time PCR.3. Results showed that silenced or overexpressed the BC1G_O8931had no obvious effect on morphology of mycelia and spore. But the ability of acid production, mycelial growth rate, pathogenicity and biomass in silence transformants were decreased, while the above four aspects all were increased in overexpression transformants. These results demonstrated that BC1G₀8931was related with mycelial growth, biomass and pathogenicity. The silence transformants produced more sclerotias and smaller sclerotia, while the sclerotia of overexpression transformants were fewer and bigger, indicated that BC1G₀8931was related to the ability of sclerotia formation.4. According to the test on the growth rate of the transformants under the different temperatures and carbon sources medium, BC1G₀8931had no significant influence on the growth of B. cinerea in different carbon sources and temperature.These results primarily indicated that BC1G₀8931was associated with mycelial growth, sclerotia formation and pathogenicity in B. cinerea.