Seed-delivered dual action RNAi for insect protection and modified plant traits

Double-stranded RNA (dsRNA) biologics used for RNA interference (RNAi)–based agricultural applications offer a powerful strategy for crop protection and trait modification, yet their deployment remains limited by the lack of efficient exogenous RNA delivery systems. While most explored approaches rely on foliar application or carrier-based formulations, we demonstrate that seeds provide an alternative entry point for non-transgenic RNA delivery to plants. Simple seed treatments enable the delivery of both small interfering RNAs (siRNAs) and long-dsRNAs into developing seedlings. Despite sharing a common entry route, the two RNA types follow distinct localisation pathways that can be exploited to achieve different functional outcomes. Seed-delivered siRNAs move into aerial tissues, access the plant cytoplasmic RNAi machinery and trigger silencing of endogenes, resulting in transitive RNAi and visible phenotypes later in development. In contrast, long-dsRNAs are largely unprocessed in the apoplast and remain available for ingestion by herbivorous insects, triggering host-delivered RNAi for insect pest control. Simultaneous seed delivery of siRNA and long-dsRNA enables dual functionality, combining endogenous plant gene silencing with insect gene knockdown from a single treatment. These findings establish seed-mediated RNA delivery as a simple and scalable platform for deploying RNAi-based crop protection and transient trait modulation without genetic modification.