Abstract
Grapevine (Vitis vinifera) teinturier cultivars are characterized by their typical reddish leaves and red-fleshed berries due to ectopic anthocyanin formation. Wines of these varieties have economic importance as they can be used for blending to enhance the color of red wines. The unique and heritable mutation has been known for a long time but the underlying genetic mechanism still is not yet understood. Here we describe the association of the red-fleshed berry phenotype with a 408 bp repetitive DNA element in the promoter of the VvmybA1 gene (grapevine color enhancer, GCE). Three different clones of ‘Teinturier’ were discovered with two, three and five allelic GCE repeats (MybA1t2, MybA1t3 and MybA1t5). All three clones are periclinal chimeras; these clones share the same L1 layer, but have distinct L2 layers with different quantities of GCE repeats. Quantitative real time PCR and HPLC analysis of leaf and berry samples showed that the GCE repeat number strongly correlates with an increase of the expression of VvmybA1 itself and the VvUFGT gene regulated by it and the anthocyanin content. A model is proposed based on autoregulation of VvmybA1t to explain the red phenotype which is similar to that of red-fleshed apples. This study presents results about the generation and modes of action of three MybA1t alleles responsible for the red-fleshed berry phenotype of teinturier grapevines.
Highlights
Anthocyanins represent a ubiquitous class of metabolites in nature [1]
For grapevines (Vitis vinifera L.), the important fruit traits with a broad spectrum ranging from green/yellow to blue/black are linked with anthocyanin-based berry color formation [4]
VvmybA1 region, expression data of anthocyanin biosynthesis genes, vines; ten ripe berries of three sun-exposed bunches were collected at three developmental stages and content and veraison, composition tissues
Summary
Anthocyanins (from Greek “anthos” = flower and “kyanos” = blue) represent a ubiquitous class of metabolites in nature [1]. They belong to the very large group of flavonoids, which includes more than 4000 known compounds that have been isolated from plants [2] and are among the most important pigments responsible for the coloration of plant tissues, especially fruits, flowers and leaves [3]. The anthocyanin biosynthesis pathway shares with all flavonoids the same upstream pathway that branches at the level of flavanones [7,8]. All precursors of the anthocyanins are colorless up to a final glycosylation by UFGT (UDP-glucose: flavonoid-3-O-glucosyltransferase) resulting in the color-intensive pigments [11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
