Resistance to RNA interference by plant‐derived double‐stranded RNAs but not plant‐derived short interfering RNAs in Helicoverpa armigera. (5th April 2022)

• Record Type: Journal Article
• Authors: Fu, Jinqiu; Xu, Shijing; Lu, Huan; Li, Fanchi; Li, Shengchun; Chang, Ling; Heckel, David G.; Bock, Ralph; Zhang, Jiang
• Is Part Of: Plant, cell and environment. Volume 45:Number 6(2022)
• Page Start: 1930
• Page End: 1941
• Publication Date: 2022-04-05
• Subjects: cotton bollworm -- double‐stranded RNA -- plastid transformation -- RNA interference -- short interfering RNA -- transgenic plants; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14314
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Plant‐mediated RNA interference (RNAi) has emerged as a promising technology for pest control through expression of double‐stranded RNAs (dsRNAs) targeted against essential insect genes. However, little is known about the underlying molecular mechanisms and whether long dsRNA or short interfering RNAs (siRNAs) are the effective triggers of the RNAi response. Here we generated transplastomic and nuclear transgenic tobacco plants expressing dsRNA against the Helicoverpa armigera ATPaseH gene. We showed that expression of long dsRNA of HaATPaseH was at least three orders of magnitude higher in transplastomic plants than in transgenic plants. HaATPaseH ‐derived siRNAs are absent from transplastomic plants, while they are abundant in transgenic plants. Feeding transgenic plants to H. armigera larvae reduced gene expression of HaATPaseH and delayed growth. Surprisingly, no effect of transplastomic plants on insect growth was observed, despite efficient dsRNA expression in plastids. Furthermore, we found that dsRNA ingested by H. armigera feeding on transplastomic plants was rapidly degraded in the intestinal fluid. In contrast, siRNAs are relatively stable in the digestive system. These results suggest that plant‐derived siRNAs may be more effective triggers of RNAi in Lepidoptera than dsRNAs, which will aid the optimization of the strategies for plant‐mediated RNAi to pest control. Summary statement: We report that plant‐derived short interference RNAs but not double‐stranded RNAs are largely resistant to degradation in the intestinal fluid and the effective RNAi triggers that induce gene silencing in Helicoverpa armigera, thus provide new opportunities for the future optimization of transgenic strategies for the control of Lepidopteran pests by RNA interference.