Characterization of a cytolytic-like gene from the aphid-obligate fungal pathogen Conidiobolus obscurus

Cytolytic (Cyt)-like genes are known by omics analyses to exist widely in bacterial and fungal pathogens, but their insecticidal activities in fungi remains unknown. A full-length coding sequence of a Cyt-like gene was first amplified from Conidiobolus obscurus (an obligate aphid-pathogenic fungus) through RACE (rapid-amplification of cDNA ends). The deduced protein structure was structurally characterized by a single Cyt-typical alpha/beta domain. The expression level of the Cyt-like gene in conidia correlated well with the fungal virulence against aphids (r(2) = 0.97). The results demonstrate the Cyt-like gene acts as an important virulence factor of C. obscurus against aphids, and has potential for exploitation in aphid control.