From plant to pharma: decoding the synthesis of BaiJi's potent polysaccharides

A pioneering study has shed light on the biosynthesis of glucomannan in Bletilla striata, a plant known as BaiJi with profound medicinal properties. The research meticulously maps the conversion process from sucrose to bioactive glucomannan polysaccharides, pinpointing key genes that orchestrate this transformation. This discovery is set to revolutionize our understanding of traditional Chinese medicine, potentially leading to the development of more effective therapeutic agents.

Bletilla striata, a key traditional Chinese medicine, is valued for its medicinal polysaccharides found in its pseudobulbs. Despite its widespread use, the cellular distribution and molecular mechanisms behind these polysaccharides' biosynthesis remain unclear. Understanding these processes is crucial for improving the medicinal quality of B. striata. Due to these challenges, in-depth research is necessary to uncover the molecular pathways and key genes involved in glucomannan synthesis, paving the way for potential genetic enhancements.

In a recent study (DOI: 10.1093/hr/uhae092) published in Horticulture Research on April 22, 2024, scientists from the Wuhan Botanical Garden of the Chinese Academy of Sciences and Hubei Normal University have unveiled the molecular mechanisms underlying the biosynthesis of glucomannan in Bletilla striata. The research provides significant insights into the polysaccharide content, composition, and distribution within the plant.

The study conducted a detailed investigation into the pseudobulbs of Bletilla striata, revealing that the primary polysaccharide is glucomannan with a mannose ratio of approximately 3:2. Through chemical and immunologic analyses, the researchers mapped the biosynthetic pathway from sucrose to glucomannan, identifying key genes such as BsGPI, BsmanA, and BsCSLAs. Gene silencing experiments demonstrated that reducing the expression of Bs03G11846 and Bs03G11849 significantly decreased glucomannan content. Additionally, yeast two-hybrid and luciferase complementation assays confirmed that these genes can form homo- or heterodimers, suggesting the formation of a complex essential for glucomannan biosynthesis. These findings provide a comprehensive understanding of the molecular mechanisms behind glucomannan production in B. striata.

Dr. Qiong Liang, the lead researcher, stated, "Our findings provide cytological evidence and characterize the key genes involved in glucomannan biosynthesis in Bletilla striata. This study lays a solid foundation for further research on the regulation mechanisms and genetic engineering of B. striata to enhance its medicinal properties."

This breakthrough in understanding the biosynthesis of glucomannan in Bletilla striata opens new avenues for genetic engineering and selective breeding. By manipulating the identified key genes, it may be possible to enhance the medicinal properties and polysaccharide content of B. striata, thus increasing its value in traditional Chinese medicine and pharmaceutical applications.

###

References

DOI

10.1093/hr/uhae092

Original Source URL

https://doi.org/10.1093/hr/uhae092

Funding information

This work was supported by the National Natural Science Foundation of China (grant numbers 31771871 and 32301633) the Hubei Provincial Natural Science Foundation of China (grant number 2023AFB281), and the Biological Resources Program, Chinese Academy of Sciences (grant numbers KFJ-BRP-007 and KFJ-BRSN-2018-6-002).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2022. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.