The regulatory factor X protein MoRfx1 is required for development and pathogenicity in the rice blast fungus Magnaporthe oryzae.
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ABSTRACT: Magnaporthe oryzae is a cereal pathogen causing 20%-30% rice yield losses. Regulatory factor X transcription factors are highly conserved proteins with diverse functions among organisms. Here, we show that MoRfx1 is required for cell division, development and pathogenicity in M. oryzae. Deletion of MoRFX1 resulted in reduced growth and conidiation, decreased appressorium turgor and impaired virulence. ?Morfx1 displayed increased sensitivity to UV light, four DNA-damaging agents and three cell wall-perturbing compounds. However, ?Morfx1 showed decreased sensitivity to bleomycin, a DNA/cell wall-damaging agent, and increased chitin content of the cell wall in vegetative mycelium. In addition, cell division speed was reduced in ?Morfx1, and ?Morfx1 did not produce three-celled conidia. RNA-sequencing and quantitative polymerase chain reaction analyses suggested that MoRfx1 has bipartite functions in the control of the expression of genes required for cell division and chitin metabolism, not only as a transcriptional repressor, but also as a transcriptional activator. In particular, the expression of chitin deacetylase genes MoCDA2 and MoCDA1 was greatly down-regulated in ?Morfx1, and deletion of MoCDA2 and MoCDA1, similar to ?Morfx1, increased resistance to bleomycin. Taken together, our results indicate that MoRFX1 regulates development and pathogenicity by modulating the expression of genes involved in cell division and cell wall integrity.
SUBMITTER: Sun D
PROVIDER: S-EPMC6638216 | biostudies-literature | 2017 Oct
REPOSITORIES: biostudies-literature
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