Drought stress enhances plastid-mediated RNA interference for efficient the willow leaf beetle management

Plastid-mediated RNA interference has emerged as a promising and effective approach for pest management. By expressing high levels of double-stranded RNAs (dsRNAs) in plastid that target essential pest genes, it has been demonstrated to effectively control certain herbivorous beetles and spider mites. However, as plants are sessile organisms, they frequently experience a combination of biotic and abiotic stresses. It remains unclear whether abiotic stress, such as drought stress, influences the accumulation of dsRNAs produced in plastids and its effectiveness in controlling pests. In this study, we aimed to investigate the effects of drought stress on dsACT expression in transplastomic poplar plants and its control efficiency against the willow leaf beetle (Plagiodera versicolora). Our findings revealed that drought stress did not significantly affect the dsRNA contents in transplastomic poplar plants, but it did lead to higher mortality of insect larvae. This increased mortality may be attributed to increased levels of jasmonic acid and cysteine proteinase inhibitor induced by water deficit. These results contribute to understanding of the mechanisms linking water deficit in plants to insect performance and provide valuable insights for implementing appropriate pest control strategies under drought stress conditions.