Salivary Proteins of Russian Wheat Aphid (Hemiptera: Aphididae)

Abstract

Salivary secretions play critical roles in aphid-host plant interactions and are responsible for damage associated with aphid feeding. The objectives of this study were to evaluate aspects of salivation and the salivary constituents of Diuraphis noxia (Hemiptera: Aphididae). Salivary proteins were isolated and compared from three aphid probed diets: pure water, 15% sucrose, or amino acids (100 mM serine, 100 mM methionine, 100 mM aspartic acid, and 15% sucrose). After 6 h, more aphids settled on sucrose diet compared with other diets, but there were no significant differences in the number of stylet sheaths produced per aphid after 24 h. There were differences in the amount of soluble salivary protein (watery saliva), with the greatest amount secreted in sucrose diet, followed by amino acid diet and pure water, respectively. Protein constituents secreted into sucrose and amino acid diets were compared using gel electrophoresis using standardized amounts of protein. More protein bands and bands of greater intensity were visualized from probed sucrose diet compared with probed amino acid diet, indicating qualitative differences. Phosphatase was putatively identified from D. noxia saliva from a major protein band using gel electrophoresis and mass spectrophotometry. Alkaline phosphatase activity was confirmed in sucrose diet using enzymatic assays but was not detected in aphid probed water or amino acid diets. Other peptides in sucrose diet weakly but significantly showed similarities to putative dehydrogenase and RNA helicase expressed sequence tags identified from other aphids. The implications of these findings in aphid salivation and plant-insect interactions are discussed.

The Leucine-Rich Repeat Receptor-Like Kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 and the Cytochrome P450 PHYTOALEXIN DEFICIENT3 Contribute to Innate Immunity to Aphids in Arabidopsis

“…Aphids secrete saliva into the plant while probing and feeding; however, the plant is not only exposed to aphid saliva, but also aphid mouthparts and honeydew. In addition, aphid saliva collected from feeding membranes differs in composition depending on the medium into which it is secreted (Cherqui and Tjallingii, 2000;Cooper et al, 2010). Studies of aphid saliva have identified proteins that were not detected in the salivary gland (Carolan et al, 2011), did not possess secretion signals (Harmel et al, 2008), or originated from bacterial endosymbionts (Filichkin et al, 1997).…”

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).…”