Kadsura coccinea Lignan Metabolism Based on Metabolome and Transcriptome Analysis

Kadsura coccinea is an important resource of traditional Chinese medicine. We find out the gene information of enzymes related to lignan biosynthesis and metabolism of Kadsura coccinea, so as to provide a scientific basis for the breeding of new varieties of Kadsura coccinea. In this paper, 2-year-old Kadsura coccinea from Hunan Kadsura coccinea provincial germplasm resource bank was used as the material and its root, stem, and leaf were analyzed by extensive targeted metabolomics combined with transcriptome sequencing. The results showed the following: (1) 51 lignans were detected by metabolome analysis, and the content of lignans in roots was higher than that in stems and leaves. The high content of lignans in roots, stems, and leaves includes ring-opening isolarch phenol-4-o-glucoside, narrow leaf schisandrin E, and schisandrin B. (2) After transcriptome sequencing, 13 classes of 137 Unigenes related to lignan biosynthesis pathway were retrieved. The analysis of differential genes in different parts showed that the overall expression amount and species of Kadsura coccinea lignan synthase gene in stems and leaves were closer than those in roots. CCoAOMT, C3H, and SIDR gene families are mainly expressed in roots and stems. (3) Metabolome combined with transcriptome analysis further screened these genes and obtained 11 genes of enzyme gene families such as HCT, DIR, COMT, CAD, SIDR, and PLR, which are highly correlated in lignan synthesis. Therefore, there are many lignans and their synthase-related genes in Kadsura coccinea roots, stems, and leaves, but the content and expression of different lignans and their synthase-related genes are quite different in each part. In this study, the gene information of the Kadsura coccinea lignan biosynthesis enzyme was obtained for the first time, which laid a good foundation for the cloning and molecular breeding of the key enzyme gene of lignan biosynthesis.