Abstract
AbstractSaliva secretion is essential for successful feeding by piercing–sucking insects. Despite extensive studies of the saliva composition of phloem- and blood-feeding insects, less is known about the oral secretions of seed-feeding insects. The firebug Pyrrhocoris apterus is a polyphagous insect that feeds primarily on dry seeds of various plant species. Here, liquid chromatography‒mass spectrometry/mass spectrometry (LC‒MS/MS) was used to identify 165 P. apterus salivary proteins, including 110 gelling-specific proteins, 24 watery-specific proteins, and 31 proteins common to both groups. Transcriptomic analysis of saliva glands identified 567 potential salivary proteins, of which 87 overlapped with those detected by LC‒MS/MS. Comparative analysis showed that 98 out of 165 (59.4%) P. apterus saliva proteins were associated with extra-oral digestion and detoxification and had homologs in ten other species of arthropods examined. In addition, 67 proteins were specific to P. apterus, of which 22 proteins were defined with unknown functions. RNA interference-mediated gene silencing assays indicated that P. apterus-specific proteins were vital for P. apterus survival. Our findings shed light on the function of salivary proteins in feeding by seed-feeding insects and the evolution of feeding habits in piercing–sucking insects.
Funder
Key Projects of Natural Science Foundation of Zhejiang Province
National Natural Science Foundation of China
Development and Demonstration of Comprehensive Technology for Prevention and Control of Major Disease and Pests
Publisher
Springer Science and Business Media LLC