Functional analysis of lncRNAs regulating the TOR signaling pathway and reproduction in the white‐backed planthopper, Sogatella furcifera

BACKGROUND: long non-coding RNAs (lncRNAs), as key endogenous regulators, have been reported to be involved in regulating insect reproduction in recent years. However, little is known about their role in the reproductive regulation of insects. RESULTS: In this study, we predicted four lncRNAs of potential cis-regulated TOR signaling pathway genes using bioinformatics analysis. They were named MSTRG.5802.1, MSTRG.5803.1, MSTRG.9854.1, and MSTRG.26502.2, and we explored their biological functions in Sogatella furcifera. RT-qPCR revealed that four lncRNAs were expressed in all life stages, with tissues specificity and were highly expressed in the head and ovary of females. Following RNAi treatment, ovarian development was significantly delayed and eggs was reduced. However, hatchability was not significantly affected. In addition, the expression levels of multiple TOR- and JH-related genes, as well as SfVg, SfVgR, and SfVg-like, were significantly decreased. With in vivo JH supplementation, the ovaries were filled with banana-shaped mature oocytes. Fecundity was also significantly higher than that of the experimental group injected with dsRNA alone, but still lower than that of the dsGFP group. CONCLUSION: Four lncRNAs play a pivotal role in ovarian development. These lncRNAs may be involved in reproductive regulation through the TOR-juvenile hormone signaling pathway. Collectively, our findings suggest these lncRNAs as potential molecular targets for developing RNAi-based biocontrol strategies against S. furcifera.