Analysis of Whitefly Transcriptional Responses to Beauveria bassiana Infection Reveals New Insights into Insect-Fungus Interactions

Abstract

BackgroundThe fungal pathogen, Beauveria bassiana, is an efficient biocontrol agent against a variety of agricultural pests. A thorough understanding of the basic principles of insect-fungus interactions may enable the genetic modification of Beauveria bassiana to enhance its virulence. However, the molecular mechanism of insect response to Beauveria bassiana infection is poorly understood, let alone the identification of fungal virulent factors involved in pathogenesis.Methodology/Principal FindingsHere, next generation sequencing technology was applied to examine the expression of whitefly (Bemisia tabaci) genes in response to the infection of Beauveria bassiana. Results showed that, compared to control, 654 and 1,681genes were differentially expressed at 48 hours and 72 hours post-infected whiteflies, respectively. Functional and enrichment analyses indicated that the DNA damage stimulus response and drug metabolism were important anti-fungi strategies of the whitefly. Mitogen-activated protein kinase (MAPK) pathway was also likely involved in the whitefly defense responses. Furthermore, the notable suppression of general metabolism and ion transport genes observed in 72 hours post-infected B. tabaci might be manipulated by fungal secreted effectors. By mapping the sequencing tags to B. bassiana genome, we also identified a number of differentially expressed fungal genes between the early and late infection stages. These genes are generally associated with fungal cell wall synthesis and energy metabolism. The expression of fungal cell wall protein genes might play an important role in fungal pathogenesis and the dramatically up-regulated enzymes of carbon metabolism indicate the increasing usage of energy during the fungal infection.Conclusions/SignificanceTo our knowledge, this is the first report on the molecular mechanism of fungus-whitefly interactions. Our results provide a road map for future investigations on insect-pathogen interactions and genetically modifying the fungus to enhance its efficiency in whitefly control.

Life‐history strategy determines constraints on immune function

“…We also detected significant downregulation of cuticle proteins, which may be biologically important as Pandora penetrates the host cuticle. Similar to other transcriptomic studies of invertebrate responses to fungal infections (Xia et al 2013), we also found differential expression of genes that may be involved in detoxification, such as cytochrome P450 and peroxidasin, and in DNA repair, such as Cop 9 signalosome. A complete list of transcripts and expression values is included as a supplementary data file.…”

Pathogenicity of Isaria fumosorosea to Bemisia tabaci, with some observations on the fungal infection process and host immune response

“…Recently, genetic sequencing technology has revealed the differential expression of hundreds of genes in B. tabaci in response to infection with the fungus Beauveria bassiana, as well as fungal genes differentially expressed at different stages of infection (Xia et al, 2013). The infection process is thus highly complex, and subject to specific host/pathogen evolutionary pathways.…”

CYP4BN6 and CYP6BQ11 mediate insecticide susceptibility and their expression is regulated by Latrophilin in Tribolium castaneum

“…61 On the other hand, a time-dependent induction of resistance genes is typically observed after 12 h. 14,24 This lag in the response is frequently due to the time needed for exogenous toxic molecules to penetrate the insect's cuticle. 62,63 Therefore, different CYPs could well act at different exposure times to protect various tissue-specific physiological pathways. Moreover, we also discovered that TcCYP4BN6 and TcCYP6BQ11 were both most highly expressed at the late pupae stage (Fig.…”