Octopamine signaling is involved in the female postmating state in Nilaparvata lugens Stål (Hemiptera: Delphacidae)

Authors: AHMAD, SHERAZ - Yangzhou University; CHEN, YU - Yangzhou University; ZHANG, JIEYU - Yangzhou University; Stanley, David; SONG, QISHENG - University Of Missouri; GE, LINQUAN - Yangzhou University

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2021
Publication Date: 6/23/2021
Citation: Ahmad, S., Chen, Y., Zhang, J., Stanley, D.W., Song, Q., Ge, L. 2021. Octopamine signaling is involved in the female postmating state in Nilaparvata lugens Stål (Hemiptera: Delphacidae). Archives of Insect Biochemistry and Physiology. 107(4). Article 21825. https://doi.org/10.1002/arch.21825.
DOI: https://doi.org/10.1002/arch.21825

Interpretive Summary: Long-term agricultural sustainability is severely threatened by widespread use of classical insecticides. Threats include increasing resistance to insecticides and sharply decreasing environmental quality. These issues drive research into alternatives to classical insecticides. One potential alternative is based on applying molecular tools to inhibit expression of genes that are crucial to insect pest biology. In this paper, we examined the impact of inhibiting a specific gene responsible for production of proteins necessary for successful reproduction in a pest insect species. We found that inhibiting this gene in females led to reduced gene expression, ovarian development, and egg-laying. These findings drive on-going research into the possibilities of applying molecular methods to develop novel pest management technologies.

Technical Abstract: Mating triggers physiological and behavioral changes in insect females, many of which are mediated by octopamine (OA). The OA mode of action remains unclear, especially in hemipterans. Here, we report that mating led to OA-induced cAMP/PKA signaling in brown planthoppers (BPH) Nilaparvata lugens Stål. RNAi silencing of TßH, which catalyzes the last step in OA biosynthesis, led to reduced expression of OA receptor, OA2B2 and reduced expression of genes in cAMP/PKA signaling pathway, including JHAMT and Met. The silencing treatments also led to reductions in circulating JHIII titer, vitellogenin synthesis and CREB1 phosphorylation. These changes coincided with reductions in body weight, soluble protein concentration, longevity, oviposition period, egg-laying, numbers of offspring and egg hatching. It also led to increased ovarian dysplasia and impaired oocyte growth. Exogenous OA injection or methoprene topical application rescued the effect of TBH silencing, indicating the synergistic actions of down-stream JHIII and OA led to post-mating changes in female reproduction. Taken together, our data support our hypothesis that OA-triggered cAMP/PKA signaling operates in female post-mating biology.