The DNA damage repair complex MoMMS21-MoSMC5 is required for infection-related development and pathogenicity of Magnaporthe oryzae

The conserved DNA damage repair complex, MMS21-SMC5/6 (Methyl methane sulfonate 21 - Structural maintenance of chromosomes 5/6), has been extensively studied in yeast, animals, and plants. However, its role in phytopathogenic fungi, particularly in the highly destructive rice blast fungus Magnaporthe oryzae, remains unknown. In this study, we functionally characterized the homologues of this complex, MoMMS21 and MoSMC5, in M. oryzae. We first demonstrated the importance of DNA damage repair in M. oryzae by showing that the DNA damage inducer phleomycin inhibited vegetative growth, infection-related development and pathogenicity in this fungus. Additionally, we discovered that MoMMS21 and MoSMC5 interacted in the nuclei, suggesting that they also function as a complex in M. oryzae. Gene deletion experiments revealed that both MoMMS21 and MoSMC5 are required for infection-related development and pathogenicity in M. oryzae, while only MoMMS21 deletion affected growth and sensitivity to phleomycin, indicating its specific involvement in DNA damage repair. Overall, our results provide insights into the roles of MoMMS21 and MoSMC5 in M. oryzae, highlighting their functions beyond DNA damage repair.