THE ROLE OF SELECTIVE AUTOPHAGY AND CELL SIGNALING IN FUNGAL DEVELOPMENT AND PATHOGENESIS

Abstract

Magnaporthe oryzae, a filamentous fungus that causes rice blast disease, was used here to study the function of mitochondrial dynamics during host pathogen interaction. Disruption of mitochondrial dynamics by deleting mitochondrial fusion or fission machineries highly reduce the pathogenicity of M. oryzae. Specifically, mitochondrial fusion is required to maintain biotrophic growth while mitochondrial fission is required for biotrophy to necrotrophy switch in M. oryzae. Subsequently, we identified that the mitochondria-to-nucleus retrograde pathway functions downstream of mitochondrial dynamics during invasive growth. In addition to mitochondrial fusion and fission, mitophagy also regulates turnover of mitochondria. We identified a mitophagy specific mediator, Atg24, in M. oryzae. Deletion of MoATG24 results in disruption of mitophagy, without affecting macroautophagy or other types of selective autophagy. Highly reduced conidiation and inhibition of invasive growth were observed in Moatg24?. To summarize, remodeling and integrity of mitochondrial network plays a key role in development of rice blast.