The immune strategy and stress response of the Mediterranean species of the Bemisia tabaci complex to an orally delivered bacterial pathogen.
BACKGROUND
The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. The interactions of the whitefly with entomopathogens as well as its endosymbionts have received great attention, because of their potential importance in developing novel whitefly control technologies. To this end, a comprehensive understanding on the whitefly defense system is needed to further decipher those interactions.


RESULTS
We conducted a comprehensive investigation of the whitefly's defense responses to infection, via oral ingestion, of the pathogen, Pseudomonas aeruginosa, using RNA-seq technology. Compared to uninfected whiteflies, 6 and 24 hours post-infected whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis of the differentially expressed genes revealed that the mitogen associated protein kinase (MAPK) pathway was activated after P. aeruginosa infection. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune responses were also activated, indicating that key immune elements recognized in other insect species are also important for the response of B. tabaci to pathogens. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly's defense against oral bacterial infection. In addition, we show stress responses to be an essential component of the defense system.


CONCLUSIONS
We identified for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This study provides a framework for future research into the complex interactions between whiteflies and microbes.
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Chang-Rong
CR
Zhang
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Shan
S
Zhang
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Jun
J
Xia
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Fang-Fang
FF
Li
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Wen-Qiang
WQ
Xia
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Shu-Sheng
SS
Liu
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Xiao-Wei
XW
Wang
D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000276:immunology; D057771:Cystine-Knot Miniproteins / Q000235:genetics* / Q000276:immunology; D005786:Gene Expression Regulation; D049750:Genome, Insect; D006430:Hemiptera / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D054884:Host-Pathogen Interactions; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D019476:Insect Proteins / Q000235:genetics* / Q000276:immunology; D008136:Longevity / Q000276:immunology; D058977:Molecular Sequence Annotation; D010572:Pest Control, Biological; D011550:Pseudomonas aeruginosa / Q000502:physiology; D013312:Stress, Physiological / Q000276:immunology
D023181:Antimicrobial Cationic Peptides; D057771:Cystine-Knot Miniproteins; D019476:Insect Proteins