UGT79B31 is responsible for the final modification step of pollen-specific flavonoid biosynthesis in Petunia hybrida

Abstract

Main conclusion UGT79B31 encodes flavonol 3- O -glycoside: 2″- O -glucosyltransferase, an enzyme responsible for the terminal modification of pollen-specific flavonols in Petunia hybrida.Flavonoids are known to be involved in pollen fertility in petunia (P. hybrida) and maize (Zea mays). As a first step toward elucidating the role of flavonoids in pollen, we have identified a glycosyltransferase that is responsible for the terminal modification of petunia pollen-specific flavonoids. An in silico search of the petunia transcriptome database revealed four candidate UDP-glycosyltransferase (UGT) genes. UGT79B31 was selected for further analyses based on a correlation between the accumulation pattern of flavonol glycosides in various tissues and organs and the expression profiles of the candidate genes. Arabidopsis ugt79b6 mutants that lacked kaempferol/quercetin 3-O-glucosyl(1 → 2)glucosides, were complemented by transformation with UGT79B31 cDNA under the control of Arabidopsis UGT79B6 promoter, showing that UGT79B31 functions as a flavonol 3-O-glucoside: 2″-O-glucosyltransferase in planta. Recombinant UGT79B31 protein can convert kaempferol 3-O-galactoside/glucoside to kaempferol 3-O-glucosyl(1 → 2)galactoside/glucoside. UGT79B31 prefers flavonol 3-O-galactosides to the 3-O-glucosides and rarely accepted the 3-O-diglycosides as sugar acceptors. UDP-glucose was the preferred sugar donor for UGT79B31. These results indicated that UGT79B31 encodes a flavonoid 3-O-glycoside: 2″-O-glucosyltransferase. Transient expression of UGT79B31 fused to green fluorescent protein (GFP) in Nicotiana benthamiana showed that UGT79B31 protein was localized in the cytosol.Electronic supplementary materialThe online version of this article (10.1007/s00425-017-2822-5) contains supplementary material, which is available to authorized users.

Tandem UGT71B5s Catalyze Lignan Glycosylation in Isatis indigotica With Substrates Promiscuity

“…To investigate the subcellular localizations of Ii UGT71B5a and Ii UGT71B5b, their ORFs were fused with YFP at the C -terminus and transiently expressed in N. benthamiana leaves. As shown in Figure 8C , the signals of both fused proteins presented in the cytoplasm, which was consistent with those of previously reported UGTs, such as Mt UGT72L1, Ph UGT79B31, and Pb UGT72AJ2 ( Pang et al, 2013 ; Knoch et al, 2018 ; Cheng et al, 2019 ). This result also indicated that the cytoplasm might be the subcellular site for lignan glycoside biosynthesis.…”

Transcriptome analysis revealed expression of genes related to anthocyanin biosynthesis in eggplant (Solanum melongena L.) under high-temperature stress

“…Sme2.5_06210.1_g00004.1 is annotated as anthocyanidin 3-O-glucosyltransferase. Studies have confirmed that this gene is a terminal modification enzyme of pollen-specific flavonol in Petunia hybrida [55]. The gene was down-regulated when eggplant fruits were exposed to high-temperature stress; then, anthocyanin synthesis decreased, and the expression of 3GT decreased, which is consistent with the findings of previous studies.…”

Integrative Transcriptomic, and Proteomic Analysis of Flavonoid Biosynthesis During Fruit Maturation In Chinese Raspberry “Rubus Chingii Hu”

“…Moreover, there is another class of avonoid glycosyltransferases, i.e. avonol 3-O-glycoside: 2''-O glucosyltransferase (3GGT/UGT79), an enzyme responsible for the terminal modi cation of pollen-speci c avonols (Knoch et al 2018). In blueberry, two 3-O glycosyltransferase genes are both up-regulated as fruit matured, while another 5-O glycosyltransferase is down-regulated (Li et al 2019).…”