The putative elongator complex protein Elp3 is involved in asexual development and pathogenicity by regulating autophagy in the rice blast fungus

Abstract

Autophagy is responsible for maintaining fundamental cellular homeostasis and is, therefore, essential for diverse development processes. This study reported that PoElp3, the putative catalytic subunit of Elongator complex, is involved in the maintenance of autophagy homeostasis to facilitate asexual development and pathogenicity in the rice blast fungus Pyricularia oryzae. It was found that the ΔPoelp3 strains were defective in vegetative growth, conidiation, stress response, and pathogenicity. The mutants exhibited hyper-activated autophagy in the vegetative hyphae under both nutrient-rich and nutrient-deficient conditions. The hyper-activation of autophagy possibly suppressed the production of vegetative hyphae in the ΔPoelp3 strains. Moreover, the ΔPoelp3 strains were found to be more sensitive to rapamycin during vegetative- and invasive-hyphal growth but have no effect on Target-of-Rapamycin (TOR) signaling inhibition. Taken together, these results demonstrated that PoElp3 is involved in asexual development and pathogenicity by regulating autophagy in the rice blast fungus.