Year-end Sale % OFF 
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 (ΔsreA) 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 ΔsreA 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 ΔsreA 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.
Highlights
Fungal infection is one of the three main diseases of crops, other than bacteria and viruses that can result in reductions in agricultural output [1]
Upc2, a typical zinc cluster protein identified in S. cerevisiae and C. albicans, was the first documented transcription factor highly correlated with fungal drug resistance [34,35,36,37]
Deletion of CaUpc2 rendered C. albicans increased susceptibility to a range of common antifungal drugs used in clinical therapy, and this increased susceptibility is observed for drugs targeting the ergosterol biosynthesis pathway [16]
Summary
Fungal infection is one of the three main diseases of crops, other than bacteria and viruses that can result in reductions in agricultural output [1]. Control of P. digitatum is critical to solving this worldwide problem; the emergence of drug-resistant strains due to excessive use of demethylation inhibitor (DMI) fungicides has resulted in less efficient control of this disease [3,4,5]. Under this circumstance, an understanding of the potential molecular mechanisms involved in DMI resistance is of great significant because it will provide a basis for the designing of novel antifungal chemicals with greater efficacy. Seven ABC proteins induced by imazalil in P. digitatum contributed to DMI fungicide efflux, and PdMFS1, a typical MFS member, is involved in imazalil-resistance and pathogenicity of P. digitatum [11,12,13,14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
