Global gene expression was analyzed in the berry skin of two red grape cultivars, which can (‘Jingyan’) or cannot (‘Jingxiu’) synthesize anthocyanins after sunlight exclusion from fruit set until maturity. Gene transcripts responding to sunlight exclusion in ‘Jingyan’ were less complex than in ‘Jingxiu’; 528 genes were induced and 383 repressed in the former, whereas 2655 genes were induced and 205 suppressed in ‘Jingxiu’. They were regulated either in the same or opposing manner in the two cultivars, or in only one cultivar. In addition to VvUFGT and VvMYBA1, some candidate genes (e.g. AOMT, GST, and ANP) were identified which are probably involved in the differential responses of ‘Jingxiu’ and ‘Jingyan’ to sunlight exclusion. In addition, 26 MYB, 14 bHLH and 23 WD40 genes responded differently to sunlight exclusion in the two cultivars. Interestingly, all of the 189 genes classified as being relevant to ubiquitin-dependent protein degradation were down-regulated by sunlight exclusion in ‘Jingxiu’, but the majority (162) remained unchanged in ‘Jingyan’ berry skin. It would be of interest to determine the precise role of the ubiquitin pathway following sunlight exclusion, particularly the role of COP9 signalosome, cullins, RING-Box 1, and COP1-interacting proteins. Only a few genes in the light signal system were found to be regulated by sunlight exclusion in either or both cultivars. This study provides a valuable overview of the transcriptome changes and gives insight into the genetic background that may be responsible for sunlight-dependent versus -independent anthocyanin biosynthesis in berry skin.

Summary This study investigated ten polyphenolic compounds in the peel of 145 apple cultivars grown in the same location while originated from different countries over two successive years. Despite significant year effect of individual and total polyphenol concentrations on each cultivar, both concentrations showed similar distributions in the 2 years, and genotypic correlations among them were relatively stable. Genotypic variations were considerable, with total polyphenol concentration ranging from 363.9 to 2516.9 μg g−1 FW. Cyanidin‐3‐galactoside was found only in red apple peels, at levels of 67.8–371.6 μg g−1 FW. Flavanols (epicatechin and catechin) and dihydrochalcones (mainly phloridzin) accounted for 8.8–66.1% and 8.58–61.2% of total polyphenols, respectively. Six flavonols (quercetin‐3‐galactoside, quercetin‐3‐glucoside, quercetin‐3‐rhamnoside, quercetin‐3‐xyloside, quercetin‐3‐arabinoside, and quercetin‐3‐rhamnoglucoside) were identified. The proportion of flavonols was 9.3–70.6% of total polyphenols. This wide variation could help in selecting cultivars with different polyphenol patterns in the peel. Principal component analysis showed that cultivars originated from different countries could not be distinguished in terms of polyphenol profiles.