Vitamins in fleshy fruits.
Résumé
Abstract This chapter focuses on three vitamins for which fleshy fruits are important sources in the human diet: two fat-soluble vitamins, the provitamin A carotenoids, which are precursors of vitamin A (retinoids), and vitamin E (tocopherols), and the water-soluble vitamin C (ascorbate). In the first part of the chapter, a general overview is given for each vitamin: its physiological role in plants, the biosynthetic pathways in fleshy fruits and regulation by genetic factors, and environmental cues in terms of fruit development and during postharvest storage. In the second part, the various strategies currently being undertaken to improve the vitamin content of fleshy fruits are reviewed, such as genetic engineering and breeding. The rapid acquisition of genome sequences and high-density-marker genetic maps in fleshy fruit species will considerably improve the speed and efficiency of the identification of genes underlying fruit vitamin quantitative trait loci and, subsequently, the transfer of the alleles of interest to elite varieties.