Transcriptome comparison of Cabernet Sauvignon grape berries from two regions with distinct climate.

Primary and secondary metabolism in grape berries is under the control of complex interactions among environmental conditions, genotypes, and management practices. To obtain an interpretation from the view of transcriptome on distinct metabolite accumulation between ecologically different regions in China, next-generation sequencing technology was performed on E-L 31, 35, and 38 stages of Cabernet Sauvignon grape berries from Changli (CL, eastern) and Gaotai (GT, western). The transcript abundance of epoxycarotenoid dioxygenase and xanthoxin dehydrogenase required for ABA biosynthesis was significantly higher in the GT berries at E-L 35 and 38 stages compared with the CL berries, which may explain the relatively short maturation period of berries in the western region. Some genes required for carbohydrate metabolism, such as hexose transporter, L-idonate dehydrogenase, and phosphoenolpyruvate carboxylase, were significantly up-regulated in the CL berries in relation to the GT berries, which positively correlated with the sugar and organic acid accumulations. Pathway enrichment analysis of differentially expressed genes revealed that the CL berries had higher levels of phenylpropanoid biosynthesis at E-L 38 stage than the GT berries, which may relate to the quick fading of the GT wines because of weak co-pigmentation. This observation lays a foundation for further study concerning the molecular basis for environmental effects on berry quality formation.