A Novel RNA Interference Target: lncRNA MSTRG.7482.1 for Control of the Rice Stem Borer Chilo suppressalis

Long noncoding RNAs (lncRNAs) have emerged as promising targets for the development of species-specific RNA interference (RNAi) strategies aimed at controlling insect pests. However, their roles in major pest species remain largely uncharacterized. In this study, we identified and conducted a functional analysis of a novel lncRNA, MSTRG.7482.1, in the destructive rice pest, Chilo suppressalis (C. suppressalis). We successfully obtained the full-length sequence of this lncRNA and observed that it exhibits a tightly regulated spatiotemporal expression pattern, with peak expression levels occurring specifically in the larval head during the critical fourth instar stage. Silencing of MSTRG.7482.1 via RNAi, achieved through the injection of two independent small interfering RNAs (siRNAs) or a long double-stranded RNA (dsRNA), resulted in effective knockdown of its expression. This suppression led to significantly reduced larval growth, as indicated by decreased weight gain. Additionally, the knockdown severely disrupted pupal development, resulting in significantly lower pupal weight and an extended pupation duration. Our findings demonstrate that MSTRG.7482.1 is essential for normal larval growth and successful pupation in C. suppressalis. This study provides the first functional evidence of an lncRNA in this pest and, importantly, establishes MSTRG.7482.1 as a highly effective RNAi target. Its disruption results in significant fitness impairments, underscoring its potential for the development of innovative, targeted management strategies against this major rice pest.