Analyses Of MED Whitefly Salivary Glands Transriptomes And Saliva Proteome

The whitefly Bemisia tabaci(Hemiptera:Aleyrodidae)is a typical piercing-sucking insect of tiny size.This wide-spread whitefly has been considered as important agricultural pests with a variety of host plants and can cause great damage to crops,including transmitting many genus of plant viruses.During whitefly feeding,its saliva plays an essential role.The saliva of whitefly includes gel saliva and watery saliva.The watery saliva may contain complex proteins that can interact with substance in plants and respond to plants’ defence responses,which ensures the whitefly’s successful feeding.The identification of the component of watery saliva can help to find out proteins involved in whitefly-plant interaction and clarify the interaction mechanism during insect feeding and transmitting virus.This study combines transcriptomics and proteomics to identify proteins in whitefly saliva.First,we sequenced the transcriptome of whitefly primary salivary glands(PSG)and accessory salivary glands(ASG)respectively.A total of 73459 unigenes with average length of 481bp in ASG and 59736 unigenes with average length of 665bp in PSG were identified.Analyses of the transcriptomic data indicated that both salivary glands have high metabolic and substance synthesis activity,and they both have the capability to synthetize proteins efficiently.We also predicted 705 and 1005 potential secreted proteins in ASG and PSG respectively,including digesting enzymes,defence related proteins,detoxification enzymes,insecticide resistance proteins and effectors in both ASG and PSG.We predicted that whitefly ASG and PSG are both involved in saliva secretion and they are likely to have similar functions.For proteomic analysis we collected large amount of whitefly saliva and conducted shotgun protein identification by Q-Exactive mass spectrum.Totally 223 peptides were identified and 155 reliable proteins were screened out with the criteria of FDR ≤0.01.Proteins in whitefly saliva identified by mass spectrum include cytochrome P450,elongation factor,heat shock protein,actin,GAPDH,some unknown genes and several oxidoreductase,some of which have been previously found in aphid and brown planthopper.This study laid the foundation for future studies in clarifying whitefly saliva component and finding more defence related proteins and effectors.