Multi-omics study uncovered key differences in taste and nutritional quality among three distinct bitter gourd (Momordica charantia L.) cultivars

Bitter gourd is a widely consumed vegetable recognized for its diverse health-promoting functions. Bitter-melon cultivars (D, B, Q) differ in consumer preferences due to quality variations. Given the lack of studies on flavor, color, and nutrition coregulation in bitter gourd, we hypothesized that these traits are driven by genetic modulation of bitterness-linked pathways. This study used comparative trans-meta-analysis to systematically explore the metabolic and molecular basis of these quality traits. The metabolome analysis shows the 8R-dihydrodehydrodiconferyl alcohol 4-O-β-D-glucopyranoside (phenolic) and borneol 7-O-[β-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside (saponin), geranyl 3-O-xylopyranosyl-glucopyranoside (saponin) all are highly induced in B and Q, while, glycosylated terpenoids (e.g. goyaglycoside, kuguaglycoside) were markedly higher in cv. D compared to other cultivars, that may cause the concurrent superior traits in D. Accordingly, DEGs encoding structural enzymes i.e. sugars (<i>SUS</i>, <i>INV</i>, <i>EGN</i>), carotenoids (<i>LCY</i>, <i>CHX</i>, <i>ZEP</i>), chlorophyll (<i>CS</i>, <i>CAO</i>), and terpenoids (<i>TTPS</i>, <i>GGPP</i>, <i>DTPS</i>) synthases were found as key-contributors. This study uncovers key mechanisms controlling taste, color and nutritional traits in bitter gourd.