Metarhizium anisopliae E6 secretome reveals new insights in cattle tick infection and the identification of potential molecular players implicated in host specificity

Abstract

Although Metarhizium anisopliae being one of the most studied fungal biocontrol agents the molecular mechanisms of its infection on different hosts is far to be completely understood. Here we analyzed secreted proteins related to the infection of the cattle tick, Rhipicephalus microplus. The results showed relative abundance changes in the expression of 194 proteins after exposure to host cuticle. Several proteins related with adhesion, penetration, stress and fungal defense were identified. We further performed a comparative genomic distribution of the differentially expressed proteins of the M. anisopliae secretome with Beauveria bassiana. Among the analyzed families, almost all of them have had a superior amount of genes identified in M. anisopliae genome. An in vivo toxicity assay using Galleria mellonella model was also performed showing that the molecular results found at genomic and proteomic level confirmed the expected higher toxic effect of M. anisopliae E6 secretome related with the cattle tick infection, over the other secretomes tested, B. bassiana related with cattle tick and M. anisopliae E6 related with the cotton stainer bug infection, Dysdercus peruvianus. This new set of results may help to explain molecular aspects associated with host infection specificity due to evolutive/gene set and gene expression control at protein level differences in arthropodpathogenic fungi.