A novel sterol regulatory element-binding protein gene (sreA) identified in penicillium digitatum is required for prochloraz resistance, full virulence and erg11 (cyp51) regulation.

ABSTRACT: Penicillium digitatum is the most destructive postharvest pathogen of citrus fruits, causing fruit decay and economic loss. Additionally, control of the disease is further complicated by the emergence of drug-resistant strains due to the extensive use of triazole antifungal drugs. In this work, an orthologus gene encoding a putative sterol regulatory element-binding protein (SREBP) was identified in the genome of P. digitatum and named sreA. The putative SreA protein contains a conserved domain of unknown function (DUF2014) at its carboxyl terminus and a helix-loop-helix (HLH) leucine zipper DNA binding domain at its amino terminus, domains that are functionally associated with SREBP transcription factors. The deletion of sreA (?sreA) in a prochloraz-resistant strain (PdHS-F6) by Agrobacterium tumefaciens-mediated transformation led to increased susceptibility to prochloraz and a significantly lower EC50 value compared with the HS-F6 wild-type or complementation strain (COsreA). A virulence assay showed that the ?sreA strain was defective in virulence towards citrus fruits, while the complementation of sreA could restore the virulence to a large extent. Further analysis by quantitative real-time PCR demonstrated that prochloraz-induced expression of cyp51A and cyp51B in PdHS-F6 was completely abolished in the ?sreA strain. These results demonstrate that sreA is a critical transcription factor gene required for prochloraz resistance and full virulence in P. digitatum and is involved in the regulation of cyp51 expression.

SUBMITTER: Liu J 

PROVIDER: S-EPMC4336317 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature