Identification of tectorigenin biosynthesis in flowers of kudzu (Pueraria montana var. lobata)

May 20, 2026

A beneficial component can be mass-produced without using rare botanical materials

Researchers at RIKEN CSRS identified the genes encoding enzymes involved in the biosynthesis of tectorigenin, an isoflavone accumulating in kudzu (Pueraria montana var. lobata) flowers. They also demonstrated that Saccharomyces cerevisiae (S. cerevisiae) can be used to produce tectorigenin in large quantities.

Kudzu flowers have long been used as herbal medicine in China, and they are now widely used in Japan as products such as supplements. Tectorigenin is a beneficial component in kudzu flowers, known for its various advantageous activities, including antioxidant and anti-tumor effects. However, the mechanism of its biosynthesis in the flowers remains unknown.

In this study, the research team selected candidate genes encoding enzymes involved in biosynthesis based on the results of a transcriptome analysis of kudzu, which comprehensively examines the information on expressed genes, and checked the functions of the candidates by expressing them in S. cerevisiae. They successfully identified genes encoding two enzymes, one involved in hydroxylating the 6th position of the isoflavone molecule (isoflavone 6-hydroxylase) and the other in transferring methyl groups to other molecules (methyltransferase), elucidating the tectorigenin biosynthesis pathway in kudzu. They also demonstrated that tectorigenin can be produced in large quantities from an inexpensive isoflavone, genistein, rich in soy beans, using S. cerevisiae into which these genes are introduced.

The findings of this study will enable the production of the beneficial component tectorigenin without using rare botanical materials, and thus are expected to contribute to improving the production of helpful compounds using biotechnology in the future.

 

Original article

Plant Biotechnology　doi: 10.5511/plantbiotechnology.26.0330b

K. Uchida, M. Y. Hirai,

"Identification of an isoflavone 6-hydroxylase involved in tectorigenin biosynthesis in kudzu (Pueraria montana var. lobata) and the efficient production of 6-methoxyisoflavones".

Contact

Kai Uchida; Research Scientist
Masami Yokota Hirai; Team Director
Metabolic Systems Research Team