An Ash1-Like Protein MoKMT2H Null Mutant Is Delayed for Conidium Germination and Pathogenesis in .

Ash1 is a known H3K36-specific histone demethylase that is required for normal Hox gene expression and fertility in and mammals. However, little is known about the expression and function of the fungal ortholog of Ash1 in phytopathogenic fungus . Here we report that MoKMT2H, an Ash1-like protein, is required for conidium germination and virulence in rice. We obtained null mutant (Δ) using a target gene replacement strategy. In the Δ null mutants, global histone methyltransferase modifications (H3K4me3, H3K9me3, H3K27me3, and H3K36me2/3) of the genome were unaffected. The Δ mutants showed no defect in vegetative hyphal growth, conidium morphology, conidiation, or disease lesion formation on rice leaves. However, the deletion mutants were delayed for conidium germination and consequently had decreased virulence. Taken together, our results indicated that MoKMT2H plays an important role in conidium germination during appressorium formation in the rice blast fungus and perhaps other pathogenic plant fungi.