Multiple loss-of-function 5-O-glucosyltransferase alleles revealed in Vitis vinifera, but not in other Vitis species

Abstract

Wild and loss-of-function alleles of the 5 - O - glucosyltransferase gene responsible for synthesis of diglucoside anthocyanins in Vitis were characterized. The information aids marker development for tracking this gene in grape breeding. Anthocyanins in red grapes are present in two glycosylation states: monoglucoside (3-O-glucoside) and diglucoside (3, 5-di-O-glucoside). While monoglucoside anthocyanins are present in all pigmented grapes, diglucoside anthocyanins are rarely found in the cultivated grape species Vitis vinifera. Biochemically 3-O-glucoside anthocyanins can be converted into 3,5-di-O-glucoside anthocyanins by a 5-O-glucosyltransferase. In this study, we surveyed allelic variation of the 5-O-glucosyltransferase gene (5GT) in 70 V. vinifera ssp. vinifera cultivars, 52 V. vinifera ssp. sylvestris accessions, 23 Vitis hybrid grapes, and 22 accessions of seven other Vitis species. Eighteen 5GT alleles with apparent loss-of-function mutations, including seven premature stop codon mutations and six frameshift indel mutations, were discovered in V. vinifera, but not in the other Vitis species. A total of 36 5GT alleles without apparent loss-of-function mutations (W-type) were identified. These W-type alleles were predominantly present in wild Vitis species, although a few of them were also found in some V. vinifera accessions. We further evaluated some of these 5GT alleles in producing diglucoside anthocyanins by analyzing the content of diglucoside anthocyanins in a set of representative V. vinifera cultivars. Through haplotype network analysis we revealed that V. vinifera ssp. vinifera and its wild progenitor V. vinifera ssp. sylvestris shared many loss-of-function 5GT alleles and extensive divergence of the 5GT alleles was evident within V. vinifera. This work advances our understanding of the genetic diversity of 5GT and provides a molecular basis for future marker-assisted selection for improving this important wine quality trait.

Comparing Wild American Grapes with Vitis vinifera: A Metabolomics Study of Grape Composition

“…The wild American grapes tend to accumulate mostly diglycosidic anthocyanins, whereas V. vinifera contains most exclusively monoglycosidic anthocyanins . Recently, it has been reported that the gene encoding for a 5- O -uridil-diphosphate-glycosyl-transferase (5-UFGT) has different alleles in V. vinifera and wild American grapes . The alleles present in the vinifera grape are almost all nonfunctional; they do not produce the 5-UFGT enzyme able to bind the glycosides to the 5-terminal end of anthocyanins.…”

Quality Characteristics and Anthocyanin Profiles of Different Vitis amurensis Grape Cultivars and Hybrids from Chinese Germplasm

“…Correlation analysis was also performed between samples' phenolic contents and antioxidant activities. Generally, the richer the phenolic content grape materials possess, the stronger the antioxidant activities their phenolic extracts [30,42,43]. The correlations in the grape seeds were extremely significant (0.965-0.989, Table S3), and there were also significant correlations (0.257-0.896, Table S2) except for the coefficients of TFA and FRAP (0.197).…”

“…9 chromosome (chr 9) might result in the inability of V. vinifera grapes to synthesize diglucoside anthocyanins [61]. Through the cloning and analysis of the 5GT allele in chr 9 from V. vinifera and other 7 Vitis spcies, Yang et al [43] found that 27 functional 5GT alleles were present in non-V. vinifera Vitis species, and 18 out of 26 5GT alleles were apparently nonfunctional in V. vinifera. He et al [62] isolated successfully a 5GT allele in chr 9 from V. amurensis 'Zuoshan-1', whose recombinant proteins were confirmed to have a 5GT function by enzymology tests; and a functional 5GT allele was found in chr 5 of V. vinifera 'Cabernet Sauvignon' [63], which might explain the trace diglucosides anthocyanins (0.23% on everage) detected in the three V. vinifera grapes of this study.…”

Identification of red grape varieties by anthocyanin profile

“…V. vinifera grapes encode an inactive 5-O-glucosyltransferase isoform truncated at the C-Terminus, which, on the contrary, is active in American Vitis species, catalyzing the biosynthesis of 3.5-O-diglucoside anthocyans [15]. Although they are sometimes found in trace amounts in red wines derived from V. vinifera, diglucosylated anthocyanins are considered characteristic compounds of grapes other than V. vinifera, and are tracked as species-specific markers [16], which is used to differentiate between V. vinifera and non-V. Vinifera species.…”