Reproductive capacity in Adelphocoris suturalis (Hemiptera: Miridae) is regulated by the insulin signaling pathway

Authors: XUE, HUI - Huazhong Agricultural University; HUANG, XINGXING - Huazhong Agricultural University; CHANG, GUOFENG - Huazhong Agricultural University; MA, WEIHUA - Huazhong Agricultural University; Hull, Joe; CHEN, LIZHEN - Huazhong Agricultural University

Submitted to: Pesticide Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2022
Publication Date: 8/13/2022
Citation: Xue, H., Huang, X., Chang, G., Ma, W., Hull, J.J., Chen, L. 2022. Reproductive capacity in Adelphocoris suturalis (Hemiptera: Miridae) is regulated by the insulin signaling pathway. Pesticide Biochemistry and Physiology. 187. Article 105195. https://doi.org/10.1016/j.pestbp.2022.105195.
DOI: https://doi.org/10.1016/j.pestbp.2022.105195

Interpretive Summary: Although the roles of insulin and other insulin-like peptides on insect physiology are well documented, their impact on plant bug reproduction remains to be fully elucidated. To begin to address this knowledge deficit, key components of the insulin signaling system in a specific species of plant bug (Adelphocoris suturalis) were identified and targeted for RNA interference (RNAi)-mediated knockdown. The genes selected include the insulin receptor itself, insulin receptor substrate 1 (IRS1), which is activated in response to insulin interactions with the insulin receptor, and forkhead box O, an insulin-dependent transcription factor. Impaired egg maturation was observed following knockdown of only IRS1. Further examination of IRS1 knockdown revealed significant reductions in lifetime egg laying and egg hatch rate as well as reduced female survival and longevity. These findings demonstrate a role for insulin signaling in plant bug reproductive development and identify a potential candidate for targeted pest management strategies that seek to disrupt the reproductive capacity of plant bugs.

Technical Abstract: The peptide hormone insulin has essential roles in regulating insect metabolism, growth, and reproduction. There are, however, few studies assessing the effects of insulin signaling on reproduction in Miridae (Hemiptera). Here, we used RNA interference (RNAi)-mediated knockdown to examine the role of three critical insulin signaling pathway components (insulin receptor, InR; insulin receptor substrate 1, IRS1; and forkhead box O, FOXO) on reproductive capacity in the mirid Adelphocoris suturalis. Knockdown of AsIRS1 led to a significant reduction in egg maturation in unmated females. To further verify the role of AsIRS1, we examined a number of reproductive parameters following knockdown. Suppression of AsIRS1 transcript levels throughout the reproductive period resulted in reduced lifetime fecundity, egg hatch rate, and oviposition capacity. Although not expansive, statistically significant deviations in female survival rate and longevity were also observed. These findings demonstrate that the insulin signaling pathway plays a key role in the reproductive development of A. suturalis, and that IRS1 is a key regulatory factor. These findings provide an important theoretical basis for the regulation of insect reproduction by insulin and introduce a new target for potential development is A. suturalis control.