Molecular Bases of Fruit Quality in Prunus Species: An Integrated Genomic, Transcriptomic, and Metabolic Review with a Breeding Perspective

Abstract

In plants, fruit ripening is a coordinated developmental process that requires the change in expression of hundreds to thousands of genes to modify many biochemical and physiological signal cascades such as carbohydrate and organic acid metabolism, cell wall restructuring, ethylene production, stress response, and organoleptic compound formation. In Prunus species (including peaches, apricots, plums, and cherries), fruit ripening leads to the breakdown of complex carbohydrates into sugars, fruit firmness reductions (softening by cell wall degradation and cuticle properties alteration), color changes (loss of green color by chlorophylls degradation and increase in non-photosynthetic pigments like anthocyanins and carotenoids), acidity decreases, and aroma increases (the production and release of organic volatile compounds). Actually, the level of information of molecular events at the transcriptional, biochemical, hormonal, and metabolite levels underlying ripening in Prunus fruits has increased considerably. However, we still poorly understand the molecular switch that occurs during the transition from unripe to ripe fruits. The objective of this review was to analyze of the molecular bases of fruit quality in Prunus species through an integrated metabolic, genomic, transcriptomic, and epigenetic approach to better understand the molecular switch involved in the ripening process with important consequences from a breeding point of view.

Visible light regulates anthocyanin synthesis via malate dehydrogenases and the ethylene signaling pathway in plum (Prunus salicina L.)

“…The primary and secondary metabolites in plum fruits changed greatly during the ripening process (García-Gómez et al, 2020, 2021. The process of fruit ripening is also a process of senescence.…”

Characterization of Japanese Plum (Prunus salicina) PsMYB10 Alleles Reveals Structural Variation and Polymorphisms Correlating With Fruit Skin Color

“…In some fruits, red color is associated with ripeness and better taste and flavor, and red fruits are also highly valued for their content of healthy compounds. Therefore, there is considerable interest in breeding these crops to obtain new varieties bearing fruits with diverse colors, hues, and patterns, while enhancing fruit nutritional quality (Ogah et al, 2014 ; Panche et al, 2016 ; García-Gómez et al, 2021 ). Such breeding efforts have been accompanied by a growing scientific interest in understanding the molecular mechanisms underlying the biosynthesis and accumulation of anthocyanins.…”

Genetic Differentiation in Anthocyanin Content among Berry Fruits

“…Anthocyanins are widely distributed secondary metabolites that play an essential role in skin pigmentation of many plant organs and microorganisms [1]. They are flavonoids by classification, sharing the same diphenylpropane skeleton (C 6 C 3 C 6 ) (Figure 1), and are predominantly found in berry fruits [2].…”

“…This is due to the accumulation of anthocyanins in the flesh and skin of the fruit [7,8]. In the case of fruits like peaches, apricots, plums, and grape berries, anthocyanins accumulate more in the skin than in the flesh [1]. Their specific color depends on the environmental pH and the presence, at the same time, of other compounds from flavone and flavonol groups and metal ions [9].…”