Metabolomic Analysis and Phenylpropanoid Biosynthesis in Hairy Root Culture of Tartary Buckwheat Cultivars

Aye Aye Thwe,Md Romij Uddin,Nam Il Park,Jae Kwang Kim,Sang Un Park,Tatsuro Suzuki,Yeon Bok Kim,Sun Ju Kim,Xiaohua Li,Richard H Barton

doi:10.1371/journal.pone.0065349

Abstract

Buckwheat, Fagopyrum tataricum Gaertn., is an important medicinal plant, which contains several phenolic compounds, including one of the highest content of rutin, a phenolic compound with anti-inflammatory properties. An experiment was conducted to investigate the level of expression of various genes in the phenylpropanoid biosynthetic pathway to analyze in vitro production of anthocyanin and phenolic compounds from hairy root cultures derived from 2 cultivars of tartary buckwheat (Hokkai T8 and T10). A total of 47 metabolites were identified by gas chromatography–time-of-flight mass spectrometry (GC-TOFMS) and subjected to principal component analysis (PCA) in order to fully distinguish between Hokkai T8 and T10 hairy roots. The expression levels of phenylpropanoid biosynthetic pathway genes, through qRT-PCR, showed higher expression for almost all the genes in T10 than T8 hairy root except for FtF3’H-2 and FtFLS-2. Rutin, quercetin, gallic acid, caffeic acid, ferulic acid, 4-hydroxybenzoic acid, and 2 anthocyanin compounds were identified in Hokkai T8 and T10 hairy roots. The concentration of rutin and anthocyanin in Hokkai T10 hairy roots of tartary buckwheat was several-fold higher compared with that obtained from Hokkai T8 hairy root. This study provides useful information on the molecular and physiological dynamic processes that are correlated with phenylpropanoid biosynthetic gene expression and phenolic compound content in F. tataricum species.

Highlights

Phenylpropanoids are a diverse group of compounds derived from the carbon skeleton of phenylalanine, which are involved in plant defense, structural support, and survival [1]
This study provides useful information on the molecular and physiological dynamic processes that are correlated with phenylpropanoid biosynthetic gene expression and phenolic compound content in F. tataricum species
A tartary buckwheat cultivar Hokkai T8 was bred by pureline selection from a Russian cultivar, Rotundatum, whereas Hokkai T10 was obtained through ethyl methane sulfonate (EMS) mutagenesis of Hokkai T8

Summary

Introduction

Phenylpropanoids are a diverse group of compounds derived from the carbon skeleton of phenylalanine, which are involved in plant defense, structural support, and survival [1]. Quercetin, gallic acid, caffeic acid, ferulic acid, 4-hydroxybenzoic acid, and 2 anthocyanin compounds were identified in Hokkai T8 and T10 hairy roots. Biotechnological production of rutin by hairy root culture of common buckwheat has been reported [16].

Results

Conclusion