Integrated Physiological and Transcriptomic Analysis Provide Insights into Anthocyanin Biosynthesis for Petal Color Formation in Jasminum sambac

Flower color is a core ornamental trait. Jasminum sambac (L.) Ait., a famous raw material for jasmine tea and fragrance, produces white flowers with extremely low seed-setting, which limits its hybrid breeding. Jasmine petals naturally accumulate pigments under biotic/abiotic stress or senescence, while relevant studies on its regulatory mechanism are limited. Here, we established a stable artificial system to reproduce petal coloration, defined four petal developmental stages, and identified cyanidin 3-rutinoside as the main pigment. At 0 h, petal abscisic acid (ABA) was at a relatively high level, and salicylic acid (SA) and ethylene (ETH) peaked at 12 h. Cyanidin 3-rutinoside initiated accumulation at 24 h and peaked at 36 h. By integrating transcriptomic and metabolomic datasets, we uncovered the regulatory TF-gene-metabolite network linked to pigment formation and pinpointed two key structural genes, dihydroflavonol 4-reductase gene (DFR) and anthocyanidin synthase gene (ANS), whose expression surged over five-fold and tightly correlated with pigment accumulation, highlighting their core functions in anthocyanin biosynthesis. JsWRKY70 and two MYBs were further identified as potential regulators of flavonoid and anthocyanin pathways. These findings deepen the understanding of jasmine petal coloration at metabolic and transcriptional levels, and reveal the molecular basis of its flavonoid and anthocyanin biosynthesis.