Stigmasterol Biosynthesis Pathway is Associated With the Dehiscence Process in Panax Ginseng Seeds

Abstract

Background: Ginseng, officially known as Panax ginseng C.A. Meyer, has been traditionally used as a medicinal herb, especially in Asia. Ginseng is propagated from seeds, and seed germination difficulty makes it challenging to grow the species naturally in farms. P. ginseng seeds typically exhibit morphophysiological dormancy. Therefore, they require both morphological and physiological dormancy releases before germination. Although some studies have proposed methods of increasing seed germination rates, the underlying mechanisms of the seed dormancy release process remain unclear. In the present study, we investigated metabolic alterations during dehiscence in P. ginseng with the aim of unraveling their potential roles in dormancy release. We compared ginseng seed metabolome before and after dehiscing, in addition to the compositions of ginsenosides and phytosterols in the two periods and the presence of associated enzymes.Results: Sugar, amino acid, and squalene concentrations were altered significantly after dehiscing. Phytosterols associated with the stigmasterol biosynthesis pathway increased after seed dehiscence, while ginsenosides and brassinosteroids were not altered significantly. In addition, squalene epoxidase, cycloartenol synthase, and 24-methylenesterol C-methyltransferase were activated after seed dehiscence.Conclusions: After seed dehiscence, the stigmasterol biosynthesis pathway was activated. Overall, our findings suggest that morphological activities that facilitate ginseng seed growth are the primary phenomena occurring during the dehiscence process. The findings of the present study enhance our understanding of P. ginseng germination processes and could promote further research on its germination and cultivation in farms.