Carotenoid content and expression of phytoene synthase and phytoene desaturase genes in bitter melon (Momordica charantia)

► Momordica charantia produces a fruit that has a β-carotene. ► Expression levels of McPSY and McPDS were high in the flowers. ► Expression levels of McPSY and McPDS decreased during the mid stages but increased in the fully mature fruit. ► Riper fruits had higher carotenoid concentrations than less ripe fruits.