Lycium barbarum, commonly known as goji berry, is renowned for its pectin polysaccharides (LBPPs), which offer a range of benefits including antioxidant, immune-regulating, and anti-aging effects. However, the absence of a genetic map for Lycium barbarum has hindered our understanding of the synthesis and regulatory mechanisms of its active components, limiting its applications in molecular breeding and biotechnology.

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

For the first time, the team revealed the complete biosynthetic pathway of LBPPs and identified key synthetic enzymes and RNA molecules involved in sugar metabolism regulation. Their findings were published in Genomics, Proteomics & Bioinformatics.

Utilizing third-generation sequencing technology, optical mapping, and their own efficient three-dimensional genome capture technology, the researchers performed a de novo genome assembly of Lycium barbarum. This approach allowed them to overcome challenges related to the high heterozygosity and repetitive nature of the Lycium barbarum genome, resulting in a high-precision genome map.

Based on this foundation, the researchers elucidated the critical role of the polysaccharide-active enzyme gene library, known as CAZymes, in the synthesis of LBPPs. They focused on three key processes: the cumulative expansion of the LBPP skeleton (RRTs), side chain synthesis (GAUTs), and chain modification (PAEs).

The study also identified a key rhamnosyltransferase gene, RRT3020, which significantly enhances LBPP production. Additionally, the researchers conducted an initial analysis of long non-coding RNAs (lncRNAs) associated with LBPP metabolism, providing new insights into gene regulation.

This study established a comprehensive model for pectin polysaccharide synthesis in Lycium barbarum, detailing the entire process from sugar transport to polysaccharide modification. These findings provide an important molecular basis for the further development and utilization of Lycium barbarum in medicinal and food applications.

Schematic diagram of pectin polysaccharide synthesis and sugar transport in Lycium barbarum (Image by CHEN Runsheng's group and CHEN Chang's group)