1887

Abstract

Regulators of the G protein signalling (RGS) pathway have been implicated in the control of a diverse array of cellular functions, including conidiation in filamentous fungi. However, the regulatory processes involved in conidiation in insect-pathogenic fungi are poorly understood. Since conidia are the infective propagules in these fungi, an understanding of the regulatory processes involved in conidiation is essential to the development of an effective biocontrol fungus. Here, the cloning and characterization of an RGS protein gene, (conidiation-associated gene), from the insect-pathogenic fungus is reported. Phylogenetic analysis showed that CAG8 was orthologous to the RGS protein FlbA from . Complementation of Δ, which cannot conidiate, with restored conidiation. Gene disruption of in resulted in the lack of conidia on agar plates and on infected insects, reduced mycelial growth, decreased virulence, lysis during growth in liquid medium as well as lack of pigmentation and irregularly shaped blastospores. Transcript levels of (hydrophobin-encoding gene) were markedly reduced in a Δ strain, while (subtilisin-like protease) transcription was unaffected. These results suggest that is involved in the modulation of conidiation, virulence and hydrophobin synthesis in .

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2007-04-01
2020-07-10
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