Abstract: To provide genetic targets for increasing the pathogenicity of Beauveria bassiana, and improve the control efficiency of B. bassiana against Plutella xylostella, the infection related genes of B. bassiana on P. xylostella was studied in this paper. The high virulence strain of B. bassiana was selected through indoor bioassay. Solexa high-throughout sequencing technology was employed in the transcriptome analysis of the pure culture of B. bassiana and the mixture sample of P. xylostella infected by B. bassiana after 48 h. Differentially expressed genes (DEGs) and their functions, classifications and pathways were analyzed by bioinformatic methods. Twenty DEGs were further identified by fluorescence quantitative PCR. Paired analysis of DEG libraries derived from B. bassiana infected larvae for 48 h and pure-cultivated B. bassiana was conducted. 8383 DEGs were obtained, which included 716 significantly differentially expressed genes. There were 350 up-regulated genes and 366 down-regulated genes. The DEGs screened in this study, especially the up-regulated genes, should be related to the infection of B. bassiana on P. xylostella. GO annotation was used to analyze the DEGs and found 26 terms, which included biological processes (11), cellular component (8) and molecular function (7). 93 up-regulated genes and 61 down-regulated genes were enriched in 12 KEGG pathways. Further analysis showed that many DEGs were enriched in infection and virulence processes, including extracellular serine-rich protein, cell wall protein, extracellular dioxygenase,siderophore iron transporter mirB and antigeniccell wall galactomannoprotein. The results of this study provided a basis for elucidating the infection mechanism of B. bassiana on P. xylostella and improving the control efficiency of B. bassiana against P. xylostella from molecular level.

Key words: Beauveria bassiana, Plutella xylostella, dip-dye related gene, transcriptome