Proteomic Comparison of Fruit Ripening between ‘Hedelfinger’ Sweet Cherry (Prunus avium L.) and Its Somaclonal Variant ‘HS’

The somaclonal variant HS, from sweet cherry (Prunus avium L.) 'Hedelfinger' (H), was previously selected for reduced tree vegetative vigor and lesser canopy density. In this work, we compared H and HS fruits at early unripe (green) and full ripe (dark red) stages by biochemical and proteomic approaches. The main biochemical parameters showed that fruit quality was not affected by somaclonal variation. The proteomic analysis identified 39 proteins differentially accumulated between H and HS fruits at the two ripening stages, embracing enzymes involved in several pathways, such as carbon metabolism, cell wall modification, stress response, and secondary metabolism. The evaluation of fruit phenolic composition by mass spectrometry showed that HS sweet cherries have higher levels of procyanidin, flavonol, and anthocyanin compounds. This work provides the first proteomic characterization of fruit ripening in sweet cherry, revealing new positive traits of the HS somaclonal variant.