Genome-wide methylation, transcriptome and metabolite reveal the balance between diosgenin and brassinosteroids in Dioscorea zingiberensis by Jialu Li lab in Wuhan University

Diosgenin, a secondary metabolite isolated from the Dioscorea spp. plant family, is an irreplaceable and ideal starting material for the synthesis of steroid hormone drugs. Dioscorea zingiberensis is the world's most desirable and important plant source of steroid hormone drugs. Brassinosteroids are an important class of phytohormones found in all plants. Diosgenin and brassinosteroids share similar structures and biosynthetic pathways, yet the regulatory networks of diosgenin and brassinosteroids biosynthesis and metabolism in plants are distinct, necessitating further elucidation of their relationship.

The group analysed the changes in the contents of cholesterol, campesterol, diosgenin and brassinosteroids in Dioscorea zingiberensis by mass spectrometry detection. The results indicated that there was a certain equilibrium relationship between the contents of diosgenin and brassinosteroids after treatment with brassinolide and brassinazole, respectively.

Through an association analysis of genome-wide methylation, transcriptome and characteristic metabolite data of Dioscorea zingiberensis, we were able to identify a number of genes and transcription factors that appear to be involved in the balance process of diosgenin and brassinosteroids including CAS, CYP90s and B3-ARFs. Our findings suggest that CAS and CYP90s may be subject to hypomethylation, which appears to be closely related to their high transcription. It was demonstrated that CAS and CYP90s play a pivotal role in the sterol homeostasis of diosgenin and brassinosteroids. The findings of this study provide compelling evidence for the balance between diosgenin and brassinosteroids.

This work offers a new perspective on the regulatory network of diosgenin and brassinosteroids biosynthesis and metabolism, as well as a new insight into the function of secondary metabolites.

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References

Authors

Zihao Li¹, Yi Li¹, Luyu Geng¹, Jiachen Wang¹, Yidan Ouyang² and Jiaru Li¹

Affiliations

1 .State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University.

2. National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan), Hubei Hongshan Laboratory, Huazhong Agricultural University.

About Jiaru Li

Dr. Jiaru Li, Professor of plant physiology & molecular biology at Wuhan University. Research in Dr. Li’s group is divided into two parts: secondary metabolism of medicinal plants, which focuses on dissecting the molecular mechanisms responsible for the biosynthesis, transportation, accumulation & conversion of plant secondary metabolites and their ecological function, and plant physiology & molecular biology, which focuses on the plant source of steroidal saponins such as Dioscorea zingiberensis, Dioscorea composita and Paris polyphylla.