Unveiling the Role of MoRph1 Histone Demethylase in Fungal Epigenetic Regulation and DNA Damage Repair for Controlling Rice Blast Disease
Rice blast, caused by the fungal pathogen Magnaporthe oryzae, threatens global food security due to its severe impact on rice production. Although histone demethylases regulate epigenetics, their role in DNA damage repair within plant pathogens remains unclear. In this study, we identified a novel putative histone demethylase, MoRph1, which interacts with the COMPASS complex and modulates fungal growth, appressorium development, and pathogenicity. MoRph1 deletion impairs fungal development and reduces virulence on rice and barley.Results: Functional analysis showed that MoRph1 exhibits slower mycelial growth, reduced conidiation, defective appressorium formation, and significantly decreased lesion formation in host. The mutant appressoria displayed compromised turgor pressure due to impaired glycogen and lipid degradation, resulting in inefficient host penetration. Subcellular localization confirmed MoRph1 nuclear residence. Furthermore, MoRph1 specifically demethylates H3K36me3 and regulates DNA damage repair-related gene expression. Nuclear abnormalities in UV stressed mutants suggest its role in maintaining genome stability.