Abstract
This study aimed to explore the physiological and biochemical mechanisms of the interaction between N. grossedentata and A. nigripes. First, specimens were categorized into low- (6.16% ± 0.66%), medium- (9.23% ± 1.19%), and high-content groups (21.23% ± 1.23%) based on the initial dihydromyricetin concentration in N. grossedentata. Subsequently, we assessed the variations in total flavonoids, dihydromyricetin, myricitrin, and myricetin in plants 24, 48, and 72 h post-feeding. Concurrently, we analyzed the impact of plant leaf consumption on the detoxifying [glutathione S-transferase (GST), carboxylesterase (CarE), acetylcholinesterase (AchE), and cytochrome P450 (CYP450)] and protective enzyme [superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT)] activities in A. nigripes, along with its metabolic processes. The results demonstrated that N. grossedentata enhanced its secondary metabolites, particularly dihydromyricetin, as a defensive response to insect-induced stress. A. nigripes utilized its detoxification and protective enzyme systems to mitigate the effects of high flavonoid levels in the host plant, with particular emphasis on the roles of detoxification enzymes (GST, AchE, CYP450, and CarE) in detoxification metabolism, which showed significant correlation (p < 0.01) with dihydromyricetin, exhibiting correlation coefficients of 0.689, 0.633, 0.579, and 0.561, respectively. Additionally, key flavonoids in N. grossedentata were observed to accumulate with different degrees during digestion and metabolism in insects. These findings lay a theoretical foundation for the further exploration of the molecular mechanisms of A. nigripes adaptation to a flavonoid-rich plant N. grossedentata and inform the development of novel pest control strategies and the selection of resistant plant varieties.