MoJMJD6, a Nuclear Protein, Regulates Conidial Germination and Appressorium Formation at the Early Stage of Pathogenesis in Magnaporthe oryzae

Abstract

In plant-pathogen interactions, <i>Magnaporthe oryzae</i> causes blast disease on more than 50 species of 14 monocot plants, including important crops such as rice, millet, and most 15 recently wheat. <i>M. oryzae</i> is a model fungus for studying plant-microbe interaction, and the main source for fungal pathogenesis in the field. Here we report that <i>MoJMJD6</i> is required for conidium germination and appressorium formation in M. oryzae. We obtained <i>MoJMJD6</i> mutants (Δ<i>Mojmjd6</i>) using a target gene replacement strategy. The <i>MoJMD6</i> deletion mutants were delayed for conidium germination, glycogen, and lipid droplets utilization and consequently had decreased virulence. In the Δ<i>Mojmjd6</i> null mutants, global histone methyltransferase modifications (H3K4me3, H3K9me3, H3K27me3, and H3K36me2/3) of the genome were unaffected. Taken together, our results indicated that <i>MoJMJD6</i> function as a nuclear protein which plays an important role in conidium germination and appressorium formation in the <i>M. oryzae</i>. Our work provides insights into <i>MoJMJD6</i>-mediated regulation in the early stage of pathogenesis in plant fungi.