The molecular and enzymatic basis of bitter/non-bitter flavor of citrus fruit: evolution of branch-forming rhamnosyltransferases under domestication.

Domestication and breeding of citrus species/varieties for flavor and other characteristics, based on the ancestral species pummelo, mandarin and citron, has been an ongoing process for thousands of years. Bitterness, a desirable flavor characteristic in the fruit of some citrus species (pummelo and grapefruit) and undesirable in others (oranges and mandarins), has been under positive or negative selection during the breeding process of new species/varieties. Bitterness in citrus fruit is determined by the composition of branched-chain flavanone glycosides, the predominant flavonoids in citrus.

ANTHOCYANIN1 from Solanum chilense is more efficient in accumulating anthocyanin metabolites than its Solanum lycopersicum counterpart in association with the ANTHOCYANIN FRUIT phenotype of tomato.

Anthocyanins are flavonoid metabolites contributing attractive colors and antioxidant qualities to the human diet. Accordingly, there is a growing interest in developing crops enriched with these compounds. Fruits of the cultivated tomato, Solanum (S.