Comparative analyses of salivary proteins from three aphid species

Abstract

Saliva is a critical biochemical interface between aphids and their host plants; however, the biochemical nature and physiological functions of aphid saliva proteins are not fully elucidated. In this study we used a multidisciplinary proteomics approach combining liquid chromatography-electrospray ionization tandem mass spectrometry and two-dimensional differential in-gel electrophoresis/matrix-assisted laser desorption/ionization time-of-flight/mass spectrometry to compare the salivary proteins from three aphid species including Acyrthosiphon pisum, Megoura viciae and Myzus persicae. Comparative analyses revealed variability among aphid salivary proteomes. Among the proteins that varied, 22% were related to DNA-binding, 19% were related to GTP-binding, and 19% had oxidoreductase activity. In addition, we identified a peroxiredoxin enzyme and an ATP-binding protein that may be involved in the modulation of plant defences. Knowledge of salivary components and how they vary among aphid species may reveal how aphids target plant processes and how the aphid and host plant interact.

The Salivary Protein Repertoire of the Polyphagous Spider Mite Tetranychus urticae: A Quest for Effectors

“…Polyphagous species are proposed to harbor a larger collection of salivary proteins because they are exposed to a greater diversity of selection pressures, i.e. host plants that vary in morphology and (defensive) physiology (52). Analogous gene family proliferations have been described for other proteins relevant for plant-spider mite interactions, such as detoxification enzymes (cytochrome P450s, carboxyl/choline esterases, and glutathione S-transferases), transporters (21,123,124), and digestive cysteine peptidases (125).…”

“…A successful approach for obtaining sufficient amounts of salivary secretions suitable for protein analysis from nonmite arthropods has been to collect secretions from artificial diets encapsulated by a membrane on which feeding has taken place. For example, using this approach, multiple proteins, in a range from 10 to 100, have been identified in the secreted saliva of aphids (51,52) and true bugs (53).…”

GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense

“…Using antibodies against Escherichia coli GroEL, the presence of this type of protein had been reported in aphid saliva (18). More recently, using proteomics, a single peptide matching to both E. coli and Buchnera GoEL has also been identified in aphid saliva (12). Because of the cross-reactivity of the GroEL antibody and the cross-match of the GroEL peptide to E. coli and Buchnera, a conclusive determination of the origin of the GroEL in aphid saliva could not be made.…”

“…However, direct profiling of the aphid salivary proteome using mass spectrometry (MS) identified only about three dozen secreted proteins (11)(12)(13)(14)(15)(16). This apparent discrepancy is likely due to the scarcity of saliva secreted by aphids in vitro.…”

Proteomic Insights into the Hidden World of Phloem Sap Feeding

“…The other common proteins belong to the GMC-oxidoreductase family and these are the most frequently reported bioactive proteins in studies of aphid saliva detected either by substrate-specifi c assays (Madhusudhan and Miles 1998 ) or by direct identifi cation using mass spectrometry (Harmel et al 2008 ;Carolan et al 2009 ;Nicholson et al 2012 ;Rao et al 2013 ;Vandermorten et al 2014 ;Nicholson and Puterka 2014 ;see Table 1 ). GMC oxidoreductase in insect saliva in general has been implicated in the modifi cation of plant defence mechanisms (Eichenseer et al 1999 ;Musser et al 2002 ;2005 ), and in aphids specifi cally is speculated to be involved in the detoxifi cation of noxious phytochemicals and in promoting the gelling of sheath saliva by enhancing disulphide bridge formation (Miles and Oertli 1993 ).…”