Differential Roles of Five Fluffy Genes (-) in the Lifecycle In Vitro and In Vivo of the Insect-Pathogenic Fungus .

The fluffy genes - are well-known players in the upstream developmental activation pathway that activates the key gene of central developmental pathway (CDP) to initiate conidiation in . Here, we report insignificant roles of their orthologs in radial growth of under normal culture conditions and different stresses although and were involved in respective responses to heat shock and HO. Aerial conidiation level was lowered in the deletion mutants of and (15%) less than of and (30%), in which the key CDP genes and were repressed consistently during normal incubation. The CDP-controlled blastospore production in submerged cultures mimicking insect hemolymph was abolished in the mutant with and being sharply repressed and decreased by 55% in the mutant with only being downregulated. The fungal virulence against a model insect was attenuated in the absence of more than of irrespective of normal cuticle infection or cuticle-bypassing infection (intrahemocoel injection). These findings unravel more important role of than of , but null roles of , in 's insect-pathogenic lifecycle and a scenario distinctive from that in .