Genes involved in Beauveria bassiana infection to Galleria mellonella

Abstract

The ascomycete fungus Beauveria bassiana is a natural pathogen of hundreds of insect species and is commercially produced as an environmentally friendly mycoinsecticide. Many genes involved in fungal insecticide infection have been identified but few have been further explored. In this study, we constructed three transcriptomes of B. bassiana at 24, 48 and 72 h post infection of insect pests (BbI) or control (BbC). There were 3148, 3613 and 4922 genes differentially expressed at 24, 48 and 72 h post BbI/BbC infection, respectively. A large number of genes and pathways involved in infection were identified. To further analyze those genes, expression patterns across different infection stages (0, 12, 24, 36, 48, 60, 72 and 84 h) were studied using quantitative RT-PCR. This analysis showed that the infection-related genes could be divided into four patterns: highly expressed throughout the whole infection process (thioredoxin 1); highly expressed during early stages of infection but lowly expressed after the insect death (adhesin protein Mad1); lowly expressed during early infection but highly expressed after insect death (cation transporter, OpS13); or lowly expressed across the entire infection process (catalase protein). The data provide novel insights into the insect-pathogen interaction and help to uncover the molecular mechanisms involved in fungal infection of insect pests.

In vivo transcriptomic analysis of Beauveria bassiana reveals differences in infection strategies in Galleria mellonella and Plutella xylostella

“…Results showed that the survival of both insects was highest at 48 h BbI, but decreased dramatically at 60 h BbI, reflecting intense fungus–insect interactions at ∼ 48 BbI. This suggests that a critical period of host–pathogen interaction occurs before 48 BbI …”

“…P. xylostella is a global insect pest that attacks crucifers, particularly cabbage, broccoli and cauliflower. Although previous studies have shown that thousands of B. bassiana genes were differentially expressed in the infection courses of both G. mellonella and P. xylostella , differences between infection strategies were unknown . Therefore, in this study, we attempted to investigate the transcriptomic differences that occur in B. bassiana at different infection stages when it infects G. mellonella and P. xylostella .…”

“…Fifth‐instar G. mellonella and third‐instar P. xylostella larvae were infected following the method reported previously . Conidia were applied by immersing larvae in an aqueous suspension containing 5 × 10 7 conidia mL −1 .…”

“…Total RNA (5 µg) was prepared for Illumina RNA‐seq according to previously reported methods . Briefly, poly(A) mRNA was purified from the total RNA using oligo(dT) beads.…”

Host–pathogen interaction after infection of Galleria mellonella with the filamentous fungus Beauveria bassiana

“…B. bassiana kills the infected host by mechanical destruction of the host tissues with the growing mycelium and by the action of secreted secondary metabolites (Vilcinskas et al ., ; Fang et al ., ; Gibson et al ., ). Recently, genes involved in B. bassiana infection of G. mellonella have been identified (Fan et al ., ; Chen et al ., ). The set of genes whose expression level changes upon the infectious process depends on the host (Zhou et al ., )…”