Prediction of a peptidome for the western tarnished plant bug Lygus hesperus

Authors: CHRISTIE, ANDREW - University Of Hawaii; Hull, Joe; Richer, Joshua; Tassone, Erica; Geib, Scott

Submitted to: General and Comparative Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2016
Publication Date: 10/24/2016
Publication URL: http://handle.nal.usda.gov/10113/63300
Citation: Christie, A.E., Hull, J.J., Richer, J.A., Tassone, E.E., Geib, S.M. 2016. Prediction of a peptidome for the western tarnished plant bug Lygus hesperus. General and Comparative Endocrinology. 243:22-38. doi: 10.1016/j.ygcen.2016.10.008.

Interpretive Summary: Neuropeptides control and regulate virtually every aspect of insect biology from growth and development to critical behaviors such as mating and feeding. Consequently, targeted disruption of these neuropeptide systems has great potential as a pest management strategy. Our knowledge of these systems in the western tarnished plant bug, an important pest of numerous crops in the western United States, is currently limited. To fill this gap, we used previously generated transcriptome databases, which contain information on the genes turned on in whole body adults including genes that encode neuropeptides, to provide an initial assessment. Specialized computer algorithms predicted the presence of 53 neuropeptides, many of which are similar to peptides with known functions. These data provide base-line information to better document the underlying physiology of the western tarnished plant bug. This knowledge is essential to fully understand how this pest interacts with its agricultural environment, and will facilitate the development of improved biologically-based management strategies.

Technical Abstract: Many strategies for controlling insect pests require an understanding of their hormonal signaling agents, peptides being the largest and most diverse single class of these molecules. Lygus hesperus is a pest species of particular concern; it responsible for millions of dollars of damage to cotton, alfalfa and strawberry crops annually. At present, little is known about the peptide hormones of L. hesperus. Here, transcriptomic data for this species were mined for sequences encoding putative peptide precursors; the pre/preprohormones deduced from the identified transcripts were subsequently used to predict mature L. hesperus peptide structures. Fifty-three L. hesperus transcripts encoding peptide precursors were identified, allowing for the prediction of a 119-sequence peptidome for this species, seven of which were amplified from adult L. hesperus heads and sequence verified. The identified peptides included isoforms of allatostatin A, allatostatin B (AST-B), allatostatin C, allatotropin, bursicon, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/ion transport peptide, diuretic hormone 31, GSEFLamide, insulin-like peptide, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pyrokinin, short neuropeptide F, SIFamide, sulfakinin and tachykinin-related peptide. Of note were several isoforms of AST-B that possess –WX7Wamide carboxyl-termini (where X7 represents seven variable residues) rather than the stereotypical –WX6Wamide (e.g., KWQDMQNPGWamide), an allatotropin ending in –SARGFamide rather than –TARGFamide (GLKNGPLNSARGFamide), a GSEFLamide ending in –GTEFLamide (TVGTEFLamide), several orcokinins with PMDEIDR– rather than NFDEIDR– amino-termini (e.g., PMDEIDRAGFTHFV), and an eight rather 12 amino acid long isoform of SIFamide (PPFNGSIFamide). Collectively, the L. hesperus peptidome predicted here provides a resource for initiating physiological investigations of peptidergic signaling in this species, including studies directed the biological control of this agricultural pest.