1887

Abstract

The filamentous fungus, , is a ubiquitously distributed insect pathogen, currently used as an alternative to chemical pesticides for pest control. Conidiospores are the means by which the fungus disseminates in the environment, and these cells also represent the infectious agent most commonly used in field applications. Little, however, is known concerning the molecular basis for maintenance of spore viability, a critical feature for survival and persistence. Here, we report on the role of a putative methyltransferase, , in conidial viability, normal fungal growth and development, and virulence, via characterization of a targeted gene knockout strain. Loss of resulted in pleiotropic effects including reduced germination, growth and conidiation, with growing mycelia displaying greater branching than the WT parent. Conidial viability dramatically decreased over time, with <5 % of the cells remaining viable after 30 days as compared with >80 % of the WT. Reduced production of extracellular proteins was also observed for the Δ mutant, including protease/peptidases, glycoside hydrolases and the hydrophobin. The latter was further confirmed by gene expression analysis. Insect bioassays using the greater wax moth, , further revealed that the Δ strain was attenuated in virulence and failed to sporulate on host cadavers. These data support a global role for in fungal physiological processes.

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2014-11-01
2020-09-19
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