Ripening of Pomegranate Skin as Revealed by Developmental Transcriptomics

Abstract

The appearance of pomegranate (Punica granatum L.) fruit is highly important for its marketing. The primary concerns are obtaining sufficient red pigment accumulation and minimal cracking of the fruit skin (the outer red layer of the peel). We analyzed the skin transcriptome of pomegranate cv. Wonderful at distinct time points of fruit development to characterize the processes that occur in the skin during fruit ripening and which may reflect on processes in the whole fruit, such as the non-climacteric nature of pomegranate. The data suggested a ripening mechanism in pomegranate skin that differs from that in strawberry—the model plant for non-climacteric fruit where abscisic acid is the growth regulator that drives ripening—involving ethylene, polyamine, and jasmonic acid pathways. The biosynthetic pathways of important metabolites in pomegranate—hydrolyzable tannins and anthocyanins—were co-upregulated at the ripening stage, in line with the visual enhancement of red coloration. Interestingly, cuticle- and cell-wall-related genes that showed differential expression between the developmental stages were mainly upregulated in the skin of early fruit, with lower expression at mid-growth and ripening stages. Nevertheless, lignification may be involved in skin hardening in the mature fruit.

Identification of fungi associated with post-harvest diseases and physicochemical analysis of sweet and sour Pomegranates in Haramoush Valley, Gilgit Baltistan, Pakistan

“…There is dual functionality of the fruit skin in safeguarding the fruit against pathogens while concurrently serving a vital role in withstanding internal growth pressures, regulating fruit expansion, and preserving overall fruit integrity. Previous studies also reveal that skin characteristics contribute significantly to the differing vulnerabilities observed between sweet and sour pomegranates [26]. This insight into the contrasting skin attributes provides a valuable perspective on potential variations in fruit resilience and quality, emphasizing the importance of understanding the unique properties of the skin in different pomegranate varieties for effective disease management and overall fruit preservation.…”

Therapeutic Potential of Punica granatum and Isolated Compounds: Evidence-Based Advances to Treat Bacterial Infections

“…Te tannin synthesis pathway is regulated by transcription factors expressed during fruit development. Studies have indicated increased expression of the shikimate dehydrogenase and UDP-glucosyltransferase genes of the shikimate pathway, suggesting increased expression of tannins and diferential expression at rind maturation compared to earlier developmental stages of the fruit [65].…”