Location: Grape Genetics ResearchTitle: Multiple loss-of-function 5-O-Glucosyltransferase alleles revealed in Vitis vinifera, but not in other Vitis species) Author
|Prins, Bernard - Bernie|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/17/2014
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Anthocyanins in red grapes (Vitis genus) are important components of wine and beneficial to human health. These antioxidant compounds 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 widely 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 through adding a glucose moiety to the 5-OH of 3-O-glucoside anthocyanins. In this study, we surveyed allelic variation of the 5-O-glucosyltransferase gene (5GT) in 70 V. vinifera spp. vinifera cultivars, 52 V. vinifera spp. sylvestris accessions, 21 Vitis hybrid grapes, and 24 accessions of other Vitis species including V. amurensis, V. riparia, V. rupestris, V. cinerea, V. labrusca, V. aestivalis, and V. rotundifolia. As many as 18 5GT alleles with apparent loss-of-function mutations, including seven premature stop codon mutations and six frame-shift indel mutations, were discovered in V. vinifera, but not in the other Vitis species. A total of 36 wild-type 5GT alleles which have no apparent loss-of-function mutations were identified. These wild-type alleles were predominantly present in wild Vitis species, although a few of them were also found in some V. vinifera spp. vinifera cultivars and V. vinifera spp. sylvestris accessions. Anthocyanin composition analysis by HPLC revealed the presence of diglucoside anthocyanins in the berries of six colored V. vinifera cultivars which carry a functional 5GT allele but not in those which don’t have functional 5GT alleles. The genetic diversity, distribution patterns and haplotype networks of these 5GT alleles were characterized among and within Vitis species. An extreme high level of polymorphisms in the 5GT gene in Vitis species and the involvement of multiple forms of mutations in creating the polymorphsims were revealed. 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.