Lycium barbarum pectin polysaccharides (LBPPs) possess various functions such as antioxidant, immune regulation, and anti-aging effects. Due to the lack of a genetic map for Lycium barbarum, little is known about the synthesis process and regulatory mechanisms of its active component, LBPPs, which limits its applications in molecular breeding and biotechnology.

Recently, a research teams led by Profs. CHEN Runsheng and CHEN Chang from the Institute of Biophysics, Chinese Academy of Sciences, have deciphered the genome map and active components of Lycium barbarum.

For the first time, they revealed the complete biosynthetic pathway of LBPPs and identified key synthetic enzymes and RNA related to sugar metabolism regulation. This study was published in Genomics, Proteomics & Bioinformatics.

Using third-generation sequencing technology, optical mapping technology, and self-developed efficient three-dimensional genome capture technology, the researchers conducted de novo genome assembly of Lycium barbarum, overcoming the challenges of high heterozygosity and high repetition in the Lycium barbarum genome, and obtained a high-precision genome map.

Based on this foundation, the researchers elucidated the core role of the polysaccharide-active enzyme gene library CAZymes in the synthesis of LBPPs, particularly in the cumulative expansion of the LBPP skeleton extension (RRTs), side chain synthesis (GAUTs), and chain modification (PAEs).

The study further identified a key rhamnosyltransferase gene RRT3020, which significantly promotes the production of LBPPs. Additionally, this work initially analyzed long non-coding RNAs (lncRNAs) associated with the metabolism of LBPPs, providing new insights into gene regulation.

This study established a comprehensive model for pectin polysaccharide synthesis in Lycium barbarum, revealing the entire synthesis process from sugar transport to polysaccharide modification, thus providing an important molecular basis for the further development and utilization of Lycium barbarum in the medicinal and food fields.

Figure. Schematic diagram of pectin polysaccharide synthesis and sugar transport in Lycium barbarum

(Image by CHEN Runsheng's group and CHEN Chang's group)

Article link: https://doi.org/10.1093/gpbjnl/qzae079

Contact: YUE Haiyan

Institute of Biophysics, Chinese Academy of Sciences

Beijing 100101, China

Email: yue_yhy@foxmail.com

(Reported by Prof. CHEN Runsheng's group and Prof. CHEN Chang's group)