The vascular wilt fungi Verticillium dahliae and the closely related Verticillium albo-atrum are devastating plant pathogens. Both pathogens produce resting structures that accumulate in soil, and are difficult to eradicate. V dahliae produces microsclerotia (MCS), while V albo-atrum produces dark resting mycelia (DRM). The role ofATG8, an autophagy marker was studied by generating A TG8 knockouts in V dahliae (vdatg8), and V albo-atrum (vaatgS). Although dispensable for pathogenicity in both species, in V dahliae ATG8 was involved in dimorphic growth, conidiation, and MCS formation, but not glycogen accumulation. Increased temperatures restored conidiation and MCS formation in vdatg8, indicating that autophagy is involved in, but not essential for MCS formation in V dahliae. In V albo-atrum ATG8 was involved in glycogen accumulation, but not DRM formation. Considerable functional redundancy exists in V dahliae MCS formation, and although VdATG8 and VaATG8 amino acid sequences are almost identical, A TG8 function is species specific
