The precious chemistry of a plant used for 2000 years in Chinese traditional medicine has been unlocked in project that raises the prospect of rapid access to a wide array of therapeutic drugs.
Carried out by Shanghai Chenshan Botanical Garden, Shanghai Institute of Plant Physiology and Ecology, and John Innes Centre of UK- the project has successfully delivered a high-quality reference genome of the mint-family member Scutellaria baicalensis Georgi.
The plant, commonly known as Chinese Skullcap, is well-known in Traditional Chinese Medicine (TCM) and is cultivated worldwide for its therapeutic properties.
Preparations of dried roots, ‘Huang Qin’, show pharmacological activities conferred by novel compounds called flavonoids, including antibacterial, antiviral, antioxidant, anti-cancer, hepatoprotective and neuroprotective properties.
Despite the commercial interest and increasing demand for Scutellaria, improvements through breeding have been limited and advances hampered by an absence of genome information.
The project team took DNA from a single plant at the Shanghai Chenshan Botanical Garden and employed a combination of sequencing strategies to successfully assemble 93% of the genome organised into 9 subsets of information or “pseudo chromosomes.”
The development means that researchers are now able to identify the genes that produce a wealth of valuable compounds then turn them into drug candidate compounds using metabolic engineering techniques in the lab.
The sequencing project outlined in the journal Molecular Plant, also provides a reference gateway for genetic exploration of other valuable members of the Lamiaceae or mint family.
“The reference genome of S. baicalensis will facilitate the development of improved assemblies of genome sequences for other members of the mint family used in TCM and offers an important foundation for decoding the synthetic pathways of valuable compounds in medicinal plants generally,” says Professor Cathie Martin, the corresponding author of the study.
This study highlights the current revival in TCM following the award of the Nobel Prize for Physiology and Medicine in 2015 to Professor You-you Tu for her discovery of artemisinin as a broad spectrum anti-malarial from Artemesia annua (wormwood).
Since then, pharmacology has started examining the healing properties of preparations from plants listed in the traditional texts, such as Shennong Bencaojing (The Divine Farmer’s Materia Medica) written between 200 and 250 AD. Such preparations have recently been reported as effective against a variety of complaints including complementary cancer treatments.
The dried root of S.biacalensis is a TCM known as Huang-Qin used for the treatment of cold, liver and lung problems as recorded by Shennong Bencaojing (The Divine Farmer’s Materia Medica) written between 2000 and 250AD.
The reference genome has already started to deliver valuable information that could be applied to development of modern remedies.
Qing Zhao from Chenshan Botanical Garden is the first author of the paper. Jun Yang is the co- first author. Scientists Mengying Cui, Jie Liu, Yumin Fang and Mengxiao Yan contributed to this study.
The full study: The Reference Genome Sequence of Scutellaria baicalensis Provides Insights into the Evolution of Wogonin Biosynthesis is published in Molecular Plant journal.
https://www.cell.com/molecular-plant/fulltext/S1674-2052(19)30131-5
