Role of Autophagy-Related Gene atg22 in Developmental Process and Virulence of Fusarium oxysporum

Abstract

Autophagy is a universal catabolic process preserved in eukaryotes from yeast to plants and mammals. The main purpose of autophagy is to degrade cytoplasmic materials within the lysosome/vacuole lumen and generate an internal nutrient pool that is recycled back to the cytosol during nutrient stress. Here, <i>Fusarium oxysporum</i> was utilized as a model organism, and we found that autophagy assumes an imperative job in affecting the morphology, development, improvement and pathogenicity of <i>F. oxysporum</i>. The search of autophagy pathway components from the <i>F. oxysporum</i> genome database recognized putative orthologs of 16 core autophagy-related (<i>ATG</i>) genes of yeast, which additionally incorporate the ubiquitin-like protein <i>atg22</i>. Present study elucidates the unreported role of <i>Foatg22</i> in formation of autophagosomes. The deletion mutant of <i>Foatg22</i> did not demonstrate positive monodansylcadaverine (MDC) staining, which exposed that <i>Foatg22</i> is required for autophagy in <i>F. oxysporum</i>. Moreover, the <i>∆Foatg22</i> strains exhibited a decrease in hyphal development and conidiation, and reduction in pathogenicity on potato tubers and leaves of potato plant. The hyphae of ∆<i>Foatg22</i> mutants were less dense when contrasted with wild-type (WT) and overexpression (OE) mutants. Our perceptions demonstrated that <i>Foatg22</i> might be a key regulator for the control of dry rot disease in tuber and root crops during postharvest stage.