Early stem growth mutation alters metabolic flux changes enhance sesquiterpenoids biosynthesis in Atractylodes lancea (Thunb.) DC.

Atractylodes lancea (Thunb.) DC. is a well-known medicinal herb in China, containing abundant active components, including a variety of sesquiterpenoids. Owing to a shortage of wild resources, artificial cultivation has become the main breeding mode, leading to the germplasm degradation. In preliminary research, our research group found that a mutant tissue culture seedling of A. lancea is an excellent germplasm resource, characterized by early stem growth and higher sesquiterpenoid content than that of the wild type. In this study, the physiological and biochemical mechanisms underlying efficient sesquiterpenoids synthesis by this mutant A. lancea were systematically evaluated. The results showed that the photosynthetic efficiency, central carbon metabolism efficiency, and energy metabolism efficiency were significantly improved in mutant A. lancea compared with the wild type, and the content of endogenous hormones, such as gibberellin and jasmonic acid, changed significantly. In addition, levels of key metabolites and the expression level of key genes in the mevalonate and 2-C-methyl-d-erythritol-4-phosphate pathways were significantly higher in mutant type than in wild type, resulting in elevated sesquiterpenoid synthesis in the mutant. These physiological and biochemical properties explain the rapid growth and high sesquiterpenoid content of mutant A. lancea.