Botrytis cinerea has been described as one of the most devastating phytopathogenic fungi responsible for grey mould disease. This ascomycete is able to infect a wide range of crop species at any plant stage and at any plant structure (leaves, fruits, roots, flowers). The infection strategy of this necrotrophic fungi is based on the acidification of its ambient environment via the production of oxalic acid and on the secretion of a set of numerous Cell Wall Degrading Enzymes. The production of some of these enzymes has been shown to be under the transcriptional control of the ambient pH. It has been established in fungi that the regulation of gene expression in response to changes in ambient pH is mediated by a conserved signal transduction pathway which has been well characterized by Penalva et al. in Aspergillus nidulans. It involves six PAL proteins and the PacC transcription zinc finger transcription factor. Under neutral or alkaline conditions, the transcription factor PacC present in an inactive form in the cytoplasm of the cell is cleaved upon activation of the signalling pathway migrates to the nucleus where it activates alkaline genes and represses acidic genes. The orthologue of the PacC gene has been identified in B.cinerea and the deletion of the gene has been carried out. Characterization of the mutant has shown that PacC is implied in several essential functions such as growth rate, spore germination, oxalic acid production. Exploration of the secreted proteins revealed that the mutant presents proteins pattern modified. This approach revealed also that the production of several proteins is independent of PacC. Through the characterization of the mutants, our work investigates the importance of the transcription factor PacC and the pH signalling in the infection process of this fungus.
Full conference title:
9th EUROPEAN CONFERENCE ON FUNGAL GENETICS
- ECFG 9th (2008)