title: Analysis of whitefly transcriptional responses to Beauveria bassiana infection reveals new insights into insect-fungus interactions.
abstract: BACKGROUND
  The 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.
  
  
  RESULTS
  Here, 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
  To 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.
authors.affiliation: Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Hangzhou, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xia
authors.forename: Chang-Rong
authors.initials: CR
authors.lastname: Zhang
authors.forename: Shan
authors.initials: S
authors.lastname: Zhang
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Li
authors.forename: Ming-Guang
authors.initials: MG
authors.lastname: Feng
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Wang
authors.forename: Shu-Sheng
authors.initials: SS
authors.lastname: Liu
mesh_terms: D000818:Animals; D052982:Beauveria / Q000502:physiology*; D001692:Biological Transport; D002473:Cell Wall / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015723:Gene Library; D003368:Gossypium / Q000469:parasitology; D006430:Hemiptera / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D054884:Host-Pathogen Interactions / Q000235:genetics; D007477:Ions / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D058977:Molecular Sequence Annotation; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D037521:Virulence Factors / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D007477:Ions; D037521:Virulence Factors