Expression analysis of the genes involved in the virulence of Beauveria bassiana

The entomopathogenic fungus Beauveria bassiana is used as a natural pest killer in many agricultural systems due to its power of overcoming the host immune system. This is partially due to its genome content that expresses key proteins involved in its virulence. In this study, we used Real-Time PCR technique to analyze the relative expression at 48 and 72 h post inoculation of the Hyd1, Hyd2, Bbchit1, Cdep1, Bbbeas, Bbbsls and Vlp4 genes implicated in the pathogenesis process of an indigenous strain (LTB) and a commercial strain (IND) of B. bassiana. This analysis revealed a higher induction of Bbbeas, Bbbsls and Vlp4 genes by the LTB strain when comparing to the IND strain and the calibrator. Furthermore, a more rapid repression of Hyd1 and Hyd2 gene was notable by LTB strain. No significant difference was recorded by the expression of the Cdep1 gene between the test samples and the control. Finally, a significant difference was recorded with the expression of Bbchit1 gene by the IND strain 72 h post-inoculation. In conclusion, these results suggest that B. bassiana strains have differential expression of virulence genes that could reflect adaptation to their geographical environment and could help classifying their entomopathogenic efficacy accordingly.