Flavonoid gene expression and metabolite profiling during fruit development in highbush blueberry (Vaccinium corymbosum L.)

• Main Author: Zifkin, Michael
• Other Authors: Constabel, Carsten Peter
• Language: en
• Published: 2011
• Subjects: blueberry; real-time quantitative PCR; gene expression; flavonoid biosynthesis; proanthocyanidin; anthocyanin; abscisic acid; fruite ripening; reference gene normalization; flavonoid hydroxylation; EST library
• Online Access: http://hdl.handle.net/1828/3658

Highbush blueberry (Vaccinium corymbosum L.) has one of the highest antioxidant capacities and flavonoid concentrations of any fruit or vegetable, and regular consumption of blueberries has been connected to a wide range of health benefits. A diversity of flavonoids (flavonols, anthocyanins, proanthocyanidins) are likely responsible for many of the health benefits, and these compounds also significantly contribute to the organoleptic properties of ripe blueberries. Despite the potential importance of these flavonoids in diet, there has been little investigation into the molecular genetics of blueberry flavonoid biosynthesis. Therefore, I developed a real-time quantitative PCR protocol to monitor expression of flavonoid genes throughout development and ripening. Following evaluation of five reference genes, expression profiling of biosynthetic genes revealed that flavonoid synthesis is tightly controlled at the transcriptional level in a biphasic developmental pattern. These results are discussed in relation to flavonoid metabolite accumulation profiles, which were produced as part of a collaboration. Finally, in conjunction with a second group of collaborating scientists, some promising preliminary evidence is provided suggesting that the hormone abscisic acid might have a role in regulating ripening initiation in blueberry. === Graduate