Identification of Saliva Proteins of the Whitefly Bemisia tabaci

The whitefly Bemisia tabaci is a notorious pest of worldwide agriculture. It is believed to secrete saliva to counter plant defenses, but the underlying mechanism remains to be elucidated. Here, we characterize the gene/protein repertoires of B. tabaci salivary glands and secreted saliva by transcriptomic and LC–MS/MS analysis. A total of 698 salivary gland-higher expressed unigenes, as well as 172 saliva proteins are identified. Comparative analysis of the saliva composition in different arthropod species illustrates that proteins associated with binding, hydrolysis and oxidation-reduction are widely distributed in herbivorous saliva. There are 74 saliva proteins exclusively identified in B. tabaci, with 34 of them being B. tabaci-specific. In addition, eleven B. tabaci-specific saliva proteins plastically regulated in response to different diets, which might be associated with wide host range of this pest. Our results gain insight into whitefly–plant interactions, and provide a good resource for functional characterization of effectors