Multi-omics Identification of a Key Glycosyl Hydrolasegene FtGH1 Involved in Rutin Hydrolysis in Tartary Buckwheat (Fagopyrum tataricum)
Published:25 Dec.2023 Source:Plant Biotechnology Journal
Rutin, a flavonoid rich in buckwheat, is important for human health and plant resistance toexternal stresses. The hydrolysis of rutin to quercetin underlies the bitter taste of Tartary buckwheat. In order to identify rutin hydrolysis genes, a 200 genotypes mini-core Tartary buckwheat germplasm resource was re-sequenced with 30-fold coverage depth.
By combiningthe content of the intermediate metabolites of rutin metabolism with genome resequencing data, metabolite genome-wide association analyses (GWAS) eventually identified a glycosyl hydrolase gene FtGH1, which could hydrolyse rutin to quercetin. This function was validatedboth in Tartary buckwheat overexpression hairy roots and in vitro enzyme activity assays. Mutation of the two key active sites, which were determined by molecular docking and experimentally verified via overexpression in hairy roots and transient expression in tobaccoleaves, exhibited abnormal subcellular localization, suggesting functional changes.
Sequenceanalysis revealed that mutation of the FtGH1 promoter in accessions of two haplotypes might benecessary for enzymatic activity. Co-expression analysis and GWAS revealed that FtbHLH165 not only repressed FtGH1 expression, but also increased seed length. This work reveals a potential mechanism behind rutin metabolism, which should provide both theoretical support in the studyof flavonoid metabolism and in the molecular breeding of Tartary buckwheat.