Increased glycyrrhizin production by the inoculation of Rhizobia in Glycyrrhiza uralensis.

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22314
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 39:Agricultural and environmental biology and related fields
• Research Institution: Saga University
• Principal Investigator: Suzuki Akihiro 佐賀大学, 農学部, 教授 (50305108)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 薬用植物 / カンゾウ / 根粒菌 / 共生 / 窒素固定 / グリチルリチン / 機能性成分

Outline of Final Research Achievements

Glycyrrhiza uralensis is a medicinal plant that contains glycyrrhizin (GL), which has various pharmacological activities. Because G. uralensis is a legume, it can establish a symbiotic relationship with Rhizobia. So, Rhizobia were isolated from root nodules of Glycyrrhiza glabra, and a rhizobium that can form root nodules in G. uralensis was selected. This rhizobium was classified as Mesorhizobium by phylogenetic analysis and was designated Mesorhizobium sp. J8. When G. uralensis plants grown from cuttings were inoculated with J8, root nodules formed. Shoot biomass and SPAD values of inoculated plants were significantly higher than those of uninoculated controls, and the GL content of the roots was 3.2 times that of controls. These results indicate that rhizobial symbiosis promotes both biomass and GL production in G. uralensis.

Free Research Field

作物生理学

Academic Significance and Societal Importance of the Research Achievements

生薬としてのウラルカンゾウの大部分は自生種を採集して調達されているが、ほぼ100 %が中国からの輸入であり、価格の高騰や供給不安などから国内栽培が推奨されている。また，ウラルカンゾウはその機能性ゆえに多くの漢方薬に配合されており、我が国は今後もウラルカンゾウの大消費国であり続けると予想される。今回の研究成果は，根粒菌の接種によってウラルカンゾウの成長が促進され，機能性成分のグリチルリチン酸の合成まで活性化されることを示すものであり，実際の栽培に適用できることになればそのインパクトは非常に大きなものとなる。