Integrated transcriptome and metabolome provide insight into phenolics and soluble sugar variation in the different varieties of Gastrodia elata Blume from different areas in China

Liangping Zha^1*Haixia Wang¹Shuo Yu¹Hanwen Yu¹Qingying Fang¹Juan Liang¹Nannan Zhi¹Chengjun Peng¹Tingyu Shan²Shuangying Gui¹

• ¹Anhui University of Chinese Medicine, Hefei, China
• ²Bozhou University, Bozhou, China

Gastrodia elata Blume is known for its "medicinal food homology", its chemical components include phenols, glycosides and polysaccharides. In China, the Anhui, Hubei, Guizhou, and Yunnan provinces are the primary G. elata-producing areas, among which Gastrodia elata Bl. f. elata (GR), Gastrodia elata Bl. f. glauca S. Chow (GB), and Gastrodia elata Bl. f. glauca S. Chow and Gastrodia elata Bl. f. elata (GR×GB) are essential varieties. In this study, 19 soluble sugars and six phenols were investigated using metabolomics and Ultra Performance Liquid Chromatography (UPLC) from different producing areas and varieties of G. elata. Sucrose, glucose, D-fructose, and D-xylose were identified as the major soluble sugar components in G. elata. The phenolic content of the same variety showed significant regional differences in different production areas. Transcriptome sequencing of 24 G. elata samples was performed. In the GR, the largest number of differentially expressed genes (DEGs) was identified in the AH-GR vs. GZ-GR comparison (4,866). In addition, 96 genes encoded 11 key enzymes in the phenolic biosynthesis pathways. In the phenolic synthesis pathway, we identified several alcohol dehydrogenase (ADH) and glucosyltransferase (GT) genes at the downstream level that potentially contribute to the variation in phenolic metabolism. Phylogenetic, structural modeling, and molecular docking analyses suggested that six GTs catalyze the production of gastrodin from p-hydroxybenzyl alcohol. This study provides a fundamental theoretical basis and data support for the selective breeding of G. elata varieties and aids in elucidating the regulatory mechanisms of phenolic active compounds.