Parallel analysis of gut and salivary glands proteomes-transcriptomes of the Bemisia tabaci NAFME cryptic species to identify effectors involved in whitefly-squash leaf curl virus transmission

Plant-infecting begomoviruses cause crop damage worldwide. They are transmitted by the whitefly Bemisia tabaci. The molecular and cellular basis for begomovirus-whitefly vector interactions are not well understood. Here, complementary approaches were used to dissect these interactions, including multidimensional chromatography and tandem mass spectrometry LC-LC-MS/MS analysis of whole adult whiteflies and the alimentary canal, or gut, and transcriptome analysis whole adult whiteflies, uts, and salivary glands (SGs). Transcripts were translated and curated and used for proteome identification, yielding six hundred and twelve unique whitefly proteins from 12 MudPIT runs. Three hundred seventy-nine unique proteins were identified from ‘whole whitefly’ proteome (9 MudPITs; 8,021 unique peptides; 67,006 spectra), and three hundred and ninety-one proteins were identified from the gut (3 MudPITs; 4,140 unique peptides; 20,135 total spectra). Annotations resulted in identification of 221whole body- and 233 gut-specific proteins. Whole body, gut, and SGs-associated proteins were associated with processes involving the endoplasmic reticulum localized protein-disulfide isomerase (catalytic activity; protein and lipid synthesis, transport, and secretion), cytoskeletal remodeling, endocytosis and membrane remodeling (dynamin GTPase), exocytosis, transport ATPases, protein, Ras-like GTP-binding proteins (actin dynamics; signaling, immunity), and heat shock protein response, among others. Selected transcripts were analyzed by real-time quantitative PCR (qRT-PCR) for differential expression in B. tabaci (NAFME) harboring Squash leaf curl virus (SLCV) and non-viruliferous whiteflies in a time-course study. Collectively, identification of over and under-expressed proteins implicated cytoskeletal remodeling and endo-exocytosis as key pathways involved in B. tabaci mediated circulative transmission of Squash leaf curl virus together with whitefly defense responses.