Differential expression of the pr1A gene in Metarhizium anisopliae and Metarhizium acridum across different culture conditions and during pathogenesis

The entomopathogenic fungi of the genus Metarhizium have severalsubtilisin-like proteases that are involved in pathogenesis and these have been usedto investigate genes that are differentially expressed in response to differentgrowth conditions. The identification and characterization of these proteases canprovide insight into how the fungus is capable of infecting a wide variety of insectsand adapt to different substrates. In addition, the pr1A gene hasbeen used for the genetic improvement of strains used in pest control. In this studywe used quantitative RT-PCR to assess the relative expression levels of thepr1A gene in M. anisopliae and M.acridum during growth in different culture conditions and duringinfection of the sugar cane borer, Diatraea saccharalis Fabricius.We also carried out a pathogenicity test to assess the virulence of both speciesagainst D. saccharalis and correlated the results with the patternof pr1A gene expression. This analysis revealed that, in bothspecies, the pr1A gene was differentially expressed under the growthconditions studied and during the pathogenic process. M. anisopliaeshowed higher expression of pr1A in all conditions examined, whencompared to M. acridum. Furthermore, M. anisopliaeshowed a greater potential to control D. saccharalis. Takentogether, our results suggest that these species have developed different strategiesto adapt to different growing conditions.