Genome-Wide Characterization and Expression Analysis of the ANS Gene Family Associated with Fruit Anthocyanin Accumulation in Two Contrasting Chinese Plums (Prunus salicina Lindl.)

Abstract

The 2-oxoglutarate/iron-dependent dioxygenase (2OGD) superfamily contains anthocyanidin synthase (ANS) genes that play vital roles in anthocyanin biosynthesis. Here, we performed a genome-wide identification of PsANS genes in Prunus salicina Lindl., and characterized their phylogeny, gene structure, conserved domains, synteny, cis-elements, and expression patterns using qRT-PCR. In total, 137 PsANS members were identified, which were unevenly distributed across eight chromosomes. Structural and conserved-motif analyses revealed conserved domain organization and functional divergence among PsANS paralogs. Synteny analysis revealed high conservation of ANS genes within Rosaceae. Numerous cis-acting elements for light, temperature, phytohormone, and stress responses were predicted in PsANS promoters, implying multi-signal networks modulate anthocyanin biosynthesis. Two contrasting Nai plum genotypes (red-fleshed Huanai and green-fleshed Qingnai) were used to investigate tissue- and cultivar-specific pigment accumulation during fruit development. Spatiotemporal expression and Person correlation analysis showed that PsANS2-35, PsANS7-8 and PsANS6-1 are promising candidate genes associated with fruit anthocyanin accumulation. This study provides candidate gene resources and theoretical support for molecular breeding of colored plum varieties.