Abstract
Hypovirus infection of the chestnut blight fungus Cryphonectria parasitica is known to downregulate the fungal laccase1 ( lac1), the modulation of which is tightly governed by the inositol triphosphate (IP 3) and calcium second messenger system in a virus-free strain. We cloned the gene cplc1 encoding a phosphatidyl inositol-specific phospholipase C (PLC), to investigate the regulation of lac1 expression and to better characterize fungal gene regulation by hypovirus. Sequence analysis of the cplc1 gene indicated that the protein product contained both the X and Y domains, which are the two conserved regions found in all known PLCs, with a 133 amino acid extension between the 2nd β-strand and the α-helix in the X domain. In addition, the gene organization appeared to be highly similar to that of a δ-type PLC. Disruption of the cplc1 gene resulted in slow growth and produced colonies characterized by little aerial mycelia and deep orange in color. Accordingly, reduced virulence of the cplc1-null mutant as compared to the wild-type was observed, which can be ascribed to the growth defect. However, other PLC-associated characteristics including temperature sensitivity and osmosensitivity did not differ from the wild-type strain. Northern blot analysis revealed no accumulation of the lac1 gene transcript due to the disruption of the cplc1 gene. Functional complementation of the cplc1-null mutant with the PLC1 gene from Saccharomyces cerevisiae restored lac1 expression, which suggests that the cloned gene encodes PLC activity. The present study indicates that the cplc1 gene is required for normal mycelial growth rate and colony morphology, and that it regulates the lac1 expression, which is also modulated by the hypovirus. Although several PLC genes have been identified in various simple eukaryotic organisms, the deletion analysis of the cplc1 gene in this study appears to be the first report on the functional analysis of PLC in filamentous fungi.
Sign-in/Register to access full text options 
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.
