Protein patterns in the salivary gland of the sunn pest, Eurygaster integriceps (Put.) (Hemiptera: Scutelleridae)

Abstract

Salivary glands of the members of the Order Hemiptera contain proteins which are involved in extra oral digestion and insect-plant interactions. Identification of proteins and determination of their physiological roles in the salivary gland is an essential step to elucidate sunn pest-wheat interactions. In this study, proteomic techniques were used to compare protein patterns in the salivary gland of fifth-instar nymphs and adults of the sunn pest, Eurygaster integriceps. Among 139 detected spots, 31 spots were selected for protein identification. Thirteen spots were differentially expressed between the two life stages. Trypsin, arginine kinase and phospholipase A2 levels were higher in the adult stage whereas chymotrypsin, arginine methyltransferase and salivary endonuclease levels were greater in fifth-instar nymphs. The remaining eighteen spots were selected for protein mapping of the salivary gland. Serine protease ssp3, alpha-amylase, glucose dehydrogenase, vacuolar H+ATPase and thrombostasin-3 were expressed at similar levels in fifth-instar nymphs and adults