Affiliation:
1. State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Insect Sciences Zhejiang University Hangzhou China
2. Analysis Center of Agrobiology and Environmental Sciences Zhejiang University Hangzhou China
Abstract
ABSTRACTNicotiana benthamiana, a widely acknowledged laboratory model plant for molecular studies, exhibits lethality to certain insect pests and can serve as a dead‐end trap plant for pest control in the field. However, the underlying mechanism of N. benthamiana's resistance against insects remains unknown. Here, we elucidate that the lethal effect of N. benthamiana on the whitefly Bemisia tabaci arises from the toxic glandular trichome exudates. By comparing the metabolite profiles of trichome exudates, we found that 51 metabolites, including five O‐acyl sugars (O‐AS) with medium‐chain acyl moieties, were highly accumulated in N. benthamiana. Silencing of two O‐AS biosynthesis genes, branched‐chain keto acid dehydrogenase (BCKD) and Isopropyl malate synthase‐C (IPMS‐C), significantly reduced the O‐AS levels in N. benthamiana and its resistance against whiteflies. Additionally, we demonstrated that the higher expression levels of BCKD and IPMS‐C in the trichomes of N. benthamiana contribute to O‐AS synthesis and consequently enhance whitefly resistance. Furthermore, overexpression of NbBCKD and NbIPMS‐C genes in the cultivated tobacco Nicotiana tabacum enhanced its resistance to whiteflies. Our study revealed the metabolic and molecular mechanisms underlying the lethal effect of N. benthamiana on whiteflies and presents a promising avenue for improving whitefly resistance.