Oglesby Lillian, Ananga Anthony, Obuya James, Ochieng Joel, Cebert Ernst, Tsolova Violeta
Center for Viticulture and Small Fruit Research, College of Agriculture and Food Science, Florida A & M University, 6505 Mahan Drive, Tallahassee, FL 32317, USA.
Food Science Program, College of Agriculture and Food Sciences, Florida A & M University, Tallahassee, FL 32307, USA.
Antioxidants (Basel). 2016 Oct 12;5(4):35. doi: 10.3390/antiox5040035.
The skin color of grape berry is very important in the wine industry. The red color results from the synthesis and accumulation of anthocyanins, which is regulated by transcription factors belonging to the MYB family. The transcription factors that activate the anthocyanin biosynthetic genes have been isolated in model plants. However, the genetic basis of color variation is species-specific and its understanding is relevant in many crop species. This study reports the isolation of , and genes from muscadine grapes for the first time. They are designated as (GenBank Accession No. KJ513437), and () (GenBank Accession No. KJ513438). The findings in this study indicate that, the deduced and protein structures share extensive sequence similarity with previously characterized plant MYBs, while phylogenetic analysis confirms that they are members of the plant MYB super-family. The expressions of , and () gene sequences were investigated by quantitative real-time PCR using in vitro cell cultures, and berry skin samples at different developmental stages. Results showed that , and genes were up-regulated in the veràison and physiologically mature red berry skins during fruit development, as well as in in vitro red cell cultures. This study also found that in ripening berries, the transcription of , and in the berry skin was positively correlated with anthocyanin accumulation. Therefore, the upregulation of , and results in the accumulation and regulation of anthocyanin biosynthesis in berry development of muscadine grapes. This work greatly enhances the understanding of anthocyanin biosynthesis in muscadine grapes and will facilitate future genetic modification of the antioxidants in .
葡萄浆果的颜色在葡萄酒行业中非常重要。红色源于花青素的合成与积累，这一过程受MYB家族转录因子调控。在模式植物中已分离出激活花青素生物合成基因的转录因子。然而，颜色变异的遗传基础具有物种特异性，对其的了解在许多作物物种中都具有重要意义。本研究首次报道了从圆叶葡萄中分离出 、 和 基因。它们被命名为 （GenBank登录号：KJ513437）和 （ ）（GenBank登录号：KJ513438）。本研究结果表明，推导的 和 蛋白质结构与先前鉴定的植物MYB具有广泛的序列相似性，而系统发育分析证实它们是植物MYB超家族的成员。利用体外细胞培养物和不同发育阶段的浆果表皮样本，通过定量实时PCR研究了 、 和 （ ）基因序列的表达。结果表明，在果实发育过程中， 、 和 基因在转色期和生理成熟的红色浆果表皮以及体外红细胞培养物中上调。本研究还发现，在成熟浆果中，浆果表皮中 、 和 的转录与花青素积累呈正相关。因此， 、 和 的上调导致了圆叶葡萄浆果发育过程中花青素生物合成的积累和调控。这项工作极大地增进了对圆叶葡萄花青素生物合成的理解，并将有助于未来对 中抗氧化剂的基因改造。
