2024/01/31 by Jana-Freja Frommann, Boas Pucker, Lennart Malte Sielmann +4 · 1 voice
Biochemistry, Genetics and Molecular Biology · Medicine · #Phytochemicals and Antioxidant Activities #Plant Gene Expression Analysis #Plant biochemistry and biosynthesis
paper · pdf · doi:10.1101/2024.01.30.577901
openalex publication_date 2024/01/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/14
Abstract Flavonoids are specialized metabolites that play important roles in plants, including interactions with the environment. The high structural diversity of this metabolite group is largely due to enzyme-mediated modifications of flavonoid core skeletons. In particular, glycosylation with different sugars is very common. In this study, the functions of the Arabidopsis thaliana glycoside hydrolase family 1-type glycosyltransferase proteins BGLU1, BGLU3 and BGLU4 were investigated, using a reverse genetics approach and untargeted metabolic fingerprinting. We screened for metabolic differences between A. thaliana wild type, loss-of-function mutants and overexpression lines and partially identified differentially accumulating metabolites, which are putative products and/or substrates of the BGLU enzymes. Our study revealed that the investigated BGLU proteins are glycosyltransferases involved in the glycosylation of already glycosylated flavonoids using different substrates. While BGLU1 appears to be involved in the rhamnosylation of a kaempferol diglycoside in leaves, BGLU3 and BGLU4 are likely involved in the glycosylation of quercetin glycosides in A. thaliana seeds. In addition, we present evidence that BGLU3 is a multifunctional enzyme that catalyzes other metabolic reactions with more complex substrates. This study deepens our understanding of the metabolic pathways and enzymes that contribute to the high structural diversity of flavonoids. Highlight The proteins BGLU1, BGLU3 and BGLU4 are involved in glycosylations of different, already glycosylated flavonoids in Arabidopsis thaliana . BGLU3 appears to be multifunctional, acting on several complex substrates.