ARS | Publication request: Random T-DNA mutagenesis identifies a Cu-Zn-superoxide dismutase gene as a virulence factor of Sclerotinia sclerotiorum

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2011
Publication Date: June 1, 2011
Citation: Xu, L., Chen, W. 2011. Random T-DNA mutagenesis identifies a Cu-Zn-superoxide dismutase gene as a virulence factor of Sclerotinia sclerotiorum. Phytopathology. 101:S104.

Technical Abstract: The Ascomycetous fungus Sclerotinia sclerotiorum is a devastating pathogen capable of infecting more than 400 plant species including many economically important crops. In order to gain a better mechanistic understanding of its non-specific host-pathogen interactions, random mutagenesis through Agrobacterium-mediated transformation (AMT) was used to identify potential virulence/pathogenicity factors in S. sclerotiorum. Screening several hundreds of AMT transformants identified two stable mutants that showed significantly less virulence in comparison with the wild type strain as measured by colonizing pea leaves in detached leaf assays. Southern hybridization analysis showed that the mutation was due to a single T-DNA insertion, and inverse PCR and DNA sequencing identified that the T-DNA insertion site was in the gene of Cu-Zn-superoxide dismutase (SOD, SS1G00699) of S. sclerotiorum. This SOD gene consists of an open reading frame of 465 bps, and its expression levels were significantly induced under oxidative stresses or during infection of pea plants. These results suggest that this SOD gene plays critical roles in detoxification of reactive oxygen species during host-pathogen interactions and is an important virulence factor of S. sclerotiorum in pathogenesis.