Host-derived artificial miRNA-mediated silencing of ecdysone receptor gene provides enhanced resistance to Helicoverpa armigera in tomato

Helicoverpa armigera causes huge crop losses due to its polyphagous nature. The present study demonstrates the use of artificial microRNA (amiRNA) mediated gene silencing approach to generate insect resistant tomato plants. Ecdysone receptor (HaEcR) gene of the target pest, H. armigera, which is involved in the regulation of all developmental stages of the insect life cycle, was silenced by sequence-specific amiRNA (amiRNA-HaEcR). Continuous feeding on detached tomato leaves expressing the amiRNA-319a-HaEcR resulted in reduced target gene transcripts and affected the overall growth and survival of H. armigera. Not only the target gene was down regulated but, the feeding also affected the expression of down-stream genes involved in the ecdysone signaling pathway. The resistant trait was also observed in T1 generation of tomato transgenic lines. These results further established the role of EcR as a master regulator in insect development and effectiveness of amiRNA technology for efficient control of H. armigera.

Automated summary

The study successfully generated insect-resistant tomato plants using amiRNA technology to silence the HaEcR gene of Helicoverpa armigera, impacting its growth and survival. In addition to down-regulating the target gene, amiRNA also affected the expression of downstream genes in the ecdysone signaling pathway. These findings highlight the role of EcR as a key regulator in insect development and the potential efficacy of amiRNA technology in controlling H. armigera.