Identification and functional characterization of phytochrome genes in the filamentous fungus Podospora anserina

Abstract:

Phytochromes play a key role in bacterial and plant development, while their roles in fungi are not fully understood. [Objective] To explore the roles of phytochrome genes PaPhy1 and PaPhy2 in the sexual reproduction and asexual development of Podospora anserina and decipher the regulatory mechanisms. [Methods] The homologous recombination method was employed to knock out the two phytochrome genes, and the resulting mutants, ΔPaPhy1 and ΔPaPhy2, were obtained. A double mutant, ΔPaPhy1ΔPaPhy2, was constructed via genetic cross. We compared the sexual production, asexual development, growth rate, and reactive oxygen metabolism between the mutants and wild-type strains under different light conditions to reveal the main roles of the phytochrome genes in P. anserina. [Results] Blue light and white light induced the formation of P. anserina ascospore shells. ΔPaPhy produced fewer ascospores in the light and showed prolonged life cycle. [Conclusion] Phytochrome genes are associated with the sexual reproduction of P. anserina. The aging delay of ΔPaPhy is related to reactive oxygen metabolism. The results of this study provide new ideas for further exploring the mechanism of light in regulating the reproduction of filamentous fungi as well as anti-aging studies.