Medicinal Quality And Genetic Research Of Golden Buckwheat(fagopyrum Cymosum) Rhizome

Golden buckwheat(Fagopyrum cymosum)is a traditional Chinese medicinal material,whicht is also included in the "Pharmacopoeia of the People’s Republic of China".Owning rich nutritional value and health care functions,golden buckwheat is widely used in both modern medicine and traditional medicine.The underground rhizomes of golden buckwheat are rich in bioflavonoid compounds and have important pharmacological activities.the content of epicatechin,one compound of flavanol,is the important indicator for testing whether the rhizomesmeets the standard of Chinese medicinal material.However,related research mainly focused on the detection of flavonoids content and pharmacological research,and the related genes involved in the biosynthesis of flavonoids in rhizomes of golden buckwheat are still unclear.In this study,211 golden buckwheat collection lines were used as the research marerials,and the basic medicinal quality traits and agronomic traits were investigated,tested and analyzed.The tested buckwheat materials can be clustered into four categories.Thereafter the transcriptome and metabolome analyses of four representative collection lines were performed.The main results of this study are as follows:1.Changes in medicinal quality traits and agronomic traits of golden buckwheat collection linesFour medicinal qualities traits(water content,ash content,alcohol-soluble extract content,flavonol content)and 6 agronomic traits(main stem height,main stem thickness,main stem branch number,main stem node number,stem color,leaf size)in 211 golden buckwheat collection lines,and epicatechin and catechins content in 50 representative golden buckwheat rhizomes were investigated and tested.Then correlation analyses among these traits were performed.Clustering analysis divided them into four groups,among which Group Ⅰ had good medicinal quality and agronomic traits,Group Ⅱ had good agronomic traits,Group Ⅲ had not so good medicinal quality and agronomic traits,Group Ⅳ had good medicinal quality traits.2.Transcription and metabolic regulation of flavonoid synthesis in buckwheat rhizomeFor each group,1~2 golden buckwheat collection linewas selected,coming to a total of 4 collection lines(H1、H2、L1、L2),.The rhizomes of them were used for transcriptome and metabolome sequencing,with 3 biological replicates.At the transcriptome level,a total of 25,165 differentially expressed genes(DEGs)were identified by pairwise comparison,of which 25 DEGs were annotated to genens in flavonoid synthesis pathway(2 PAL,4 C4 H,2 4CL,5 CHS,1 CHI,2 F3’5’H,1 F3’H,1 F3 H,1 DFR,1 FLS,2 LAR,2 UFGT and 1 ANR).QRT-PCR was used to verify transcriptome data,the results of 21 DEGs were consistent with their transcriptome results(Pearson R > 0.7).At the metabolome level,a total of 439 metabolites were detected,which were divided into 11 categories: flavonoids,amino acids and their derivatives,phenolic acids,lipids,organic acids,nucleotides and their derivatives,alkaloids,tannins,quinones,lignansm coumarins,and others.A total of 90 flavonoids were detected,including 30 flavonoids,25 flavonols,15 flavanols,7 dihydroflavonoids,5 flavonoid glycosides,and 8 other flavonoids.Through combined analyses of transcriptome and metabolome,the key regulatory pathway of flavonoids synthesis of golden buckwheat rhizomes was constructed.22 key flavonoid synthesis genes were closely related to 16 key metabolites.This study preliminarily explored the regulation mechanism of flavonoids biosynthesis in golden buckwheat rhizomes,which laid foundation for the molecular breeding of high flavonoids content in golden buckwheat.