Functional Analysis Of Sclerotial Formation And Pathogenicity Associated Gene SOP1in Sclerotinia Sclerotiorum

Sclerotinia sclerotiorum is an important plant pathogenic fungus with a worldwide distribution, and this fungus can infect408species at least. Sclerotium, which can survive many years in soil and play key roles in the life cycle, is the main form through the hard situation. Therefore, study on the molecular mechanisms of sclerotial formation and pathogenicity is important in the control of disease caused by S. sclerotiorum. Based on the S. sclerotiorum digital gene expression profile (DGE) and using the bioinformatic method we obtained a G protein-coupled receptor (GPCRs) like gene SOP1, which was related to the sclerotial formation and pathogenicity. The function of this gene was studied using Gene Silence technology. The main results are listed as following:1. SOP1is composed of1058bp containing three exons and two introns. Its cDNA sequence was942bp encoding313amino acids. In DGE profile, the expression level of SOP1significantly increased at stages of sclerotial formation and pathogenicity, which was confirmed with the Real-time quantitative PCR (qRT-PCR) data. The results suggested that SOP1maybe related to the sclerotial formation and pathogenicity. Protein SOP1was pridicted to contain seven transmembrane helixes and a conserved bacteriorhodopsin domain. Phylogenetic analysis revealed that homologs of SOP1exsisted in archaea, bacteria, blue algae and partial fungus, but not in higher plants and animals.2. Silencing vector of SOP1was constructed, and then transformed to S. sclerotiorum strain Ep-1PNA367by ATMT method. Comparsion to the strain Ep-1PNA367, the expression level of SOP1declined significantly in silencing transformants.3. Biological experiments suggested that SOP1has a relationship with mycelial growth, sclerotial formation and pathogenicity. The tests of stress revealed that SOP1play roles in maintaining the integrity of cell wall and membrane, H2O2tolerance, and pesticide resistance. These results primarily indicated the roles of SOP1in mycelial growth, sclerotium formation, pathogenicity and the integrity of cell wall and membrane.