Comparisons of Salivary Proteins From Five Aphid (Hemiptera: Aphididae) Species

Abstract

Aphid (Hemiptera: Aphididae) saliva, when injected into host plants during feeding, causes physiological changes in hosts that facilitate aphid feeding and cause injury to plants. Comparing salivary constituents among aphid species could help identify which salivary products are universally important for general aphid feeding processes, which products are involved with specific host associations, or which products elicit visible injury to hosts. We compared the salivary proteins from five aphid species, namely, Diuraphis noxia (Kurdjumov), D. tritici (Gillette), D. mexicana (Baker), Schizaphis graminum (Rondani), and Acyrthosiphon pisum (Harris). A 132-kDa protein band was detected from the saliva of all five species using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Alkaline phosphatase activity was detected from the saliva of all five species and may have a universal role in the feeding process of aphids. The Diuraphis species cause similar visible injury to grass hosts, and nine electrophoretic bands were unique to the saliva of these three species. S. graminum shares mutual hosts with the Diuraphis species, but visible injury to hosts caused by S. graminum feeding differs from that of Diuraphis feeding. Only two mutual electrophoretic bands were visualized in the saliva of Diuraphis and S. graminum. Ten unique products were detected from the saliva of A. pisum, which feeds on dicotyledonous hosts. Our comparisons of aphid salivary proteins revealed similarities among species which cause similar injury on mutual hosts, fewer similarities among species that cause different injury on mutual hosts, and little similarity among species which feed on unrelated hosts.

Proteomic analysis of secreted saliva from Russian Wheat Aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat

“…This model is supported by the occurrence of low protein numbers for RWA1 and 8 (least virulent), and the highest numbers of salivary proteins for RWA2 (most virulent), with the exception of RWA5, a biotype of intermediate virulence, that displayed the lowest number of salivary proteins. Other studies have found limited genetic variation among D. noxia biotypes [37], biotypic proteome variation in whole-body extracts of S. graminum [38], and variation among salivary proteomes of separate aphid species [20] which supports the high level of variation found among RWA biotypes in our results. Our research is the first to demonstrate protein differences in the saliva of aphids at the biotype level within an aphid species.…”

“…There were thirty-eight individual protein bands ranging from <10 kDa to > 250 kDa and the majority of these bands were previously undetected in D. noxia [15,20]. The most intense protein bands in each RWA biotype were located at 45, 50, 80, and 95 kDa.…”

“…Watery saliva is a complex mixture of amino acids, proteins (e.g. hydrolases, oxidases) and other materials that the aphid uses to modify plant defenses and phloem chemistry in order to successfully feed on the phloem [10,12,13,15,[19][20][21]. The aphid's watery saliva contains a wide range of protein classes with distinct functions [13][14][15]21,22] which act in concert to allow the aphid to continue feeding while avoiding further elicitation of plant defenses.…”

Chlorophyll Content of Aphid-Infested Seedling Leaves of Fifteen Maize Genotypes

“…One such effect is chlorosis (Heng-Moss et al, 2003;Smith et al, 2005;Botha et al, 2006;Diaz-Montano et al, 2007;Goławska et al, 2010). Highly bioactive effector molecules in aphid salivary gland secretions may cause severe damage to infested plants (Cooper et al, 2010;Cooper et al, 2011;Nicholson et al, 2012;Rao et al, 2013). Although Z. mays is one of the most important model plants and a valuable crop, there has been no published assessment of aphid-evoked changes in the total chlorophyll concentration of seedlings representing a wide range of genotypes.…”

A novel virus from Macrosiphum euphorbiae with similarities to members of the family Flaviviridae

“…Recently, with the development of genomics and transcriptomic resources and the availability of highly sensitive proteomics technology, the composition of saliva from a number of aphid species, including the potato aphid, has been investigated (Carolan et al, 2009(Carolan et al, , 2011Chaudhary et al, 2014Chaudhary et al, , 2015Cooper et al, 2010Cooper et al, , 2011Harmel et al, 2008;Nicholson et al, 2012;Rao et al, 2013;Vandermoten et al, 2014). Almost all proteins identified in the potato aphid saliva had homologues in the pea aphid (Acyrthosiphum pisum), the only aphid with a published genome sequence (International Aphid Genomics Consortium, 2010).…”