Content of phenol and stilbene compounds and gene expression related to fruit development during ripening in Ampelopsis

Abstract

AbstractGrapes are used worldwide and are rich in polyphenols, such as anthocyanins and stilbene compounds. Wild grapes contain abundant stilbene compounds, which are beneficial to humans. This study examined the polyphenol content and gene expression involved in skin coloration in the ripening stage of Ampelopsis spp. Accession compared to ‘VC-1’ (Vitis coignetiae) and ‘Super Hamburg’ (V. labruscana). The flavonoid content was generally higher in the Ampelopsis fruit than in the other grape lines, and the highest content among Ampelopsis accessions was found in ‘YG10075’ at 9.67 mg quercetin equivalent (QE) per g fresh weight. The anthocyanin content was highest in ‘VC-1’ at 1.2% (w/w), and the Ampelopsis accession with the highest anthocyanin content was ‘YG10062’ with 0.27%. The resveratrol content was highest in ‘VC-1’ at 70.4 μg/g, and the Ampelopsis accession with the highest resveratrol content was ‘YG10075’ with 48.5 μg/g. Expression levels of genes involved in skin color development increased during maturation in ‘VC-1’ and ‘Super Hamburg’, but decreased with maturation in Ampelopsis ‘YG10042’, ‘YG10075’, and ‘YG10062’. The expression of the genes related to stilbene compound synthesis, skin coloration, and reactive oxygen species (ROS) was high in the leaves of ‘YG10045’, young berries of ‘YG10075’, and ripe berries ‘YG-Songni4’. The gene expression showed different patterns depending on the accession of Ampelopsis, the organ, and the ripening stage. Our results indicate that ‘YG-Songni4’ is the most valuable Ampelopsis spp. accession with the highest expression of genes related to synthesis of stilbenic compounds throughout all organs. This accession could be a useful genetic resource in grape breeding programs.