Fe induced a dynamic and biased allocation of material flux within terpenoid metabolism is controlled by CbNudix in Conyza blinii

Conyza blinii is a unique traditional Chinese medicine growing in Sichuan, China, which has soils with an abundant iron content. This Fe-enriched environment contributes to a variety of terpenoids in C. blinii, such as blinin and saponin, which play an important role in the process of resisting abiotic stress. The relationship between Fe and terpenoid metabolism was studied to explore the Fe tolerance mechanism of C. blinii. In this study, C. blinii was treated with ferrous iron solutions, and the effect of ferrous iron on the synthesis of blinin and saponins was further studied by spectrophotometry and liquid chromatography. Additionally, gene expression was detected by qRT-PCR. Under ferrous treatment, the blinin content of C. blinii increased, while the total saponin content decreased. When the ferrous concentration reached 200 μM, the difference in metabolite production was the largest. Furthermore, it was found that blinin and saponins have synchronous and opposite accumulation trends, characterized by time dependence. The gene expression results of key enzymes in the MVA and MEP pathways showed the same trends. In this process, the expression of CbNudixs played a key role in switching the material flux between MVA and MEP by catalyzing the dephosphorylation of isoprenoid diphosphate. In this study, it was found that under ferrous iron stimulation, the terpenoid content in C. blinii was different, and the metabolic pathways of MVA and MEP were periodically regulated.