Why is Golden Rice pale yellow in color?

Golden Rice (Oryza sativa) denotes a genetically modified rice capable of biosynthesizing and accumulating ?-carotene (provitamin A) in the endosperm, yielding a characteristic yellow color in the polished grains. Golden rice was developed to help cope with vitamin A deficiency, a problem that prevails in developing countries, affecting millions (Underwood, 2000; UNICEF, 2000). Vitamin A deficiency causes mortality and growth retardation in children and frequently impairs vision, leading to blindness. It also contributes indirectly to anemia by interfering with iron bioavailability.

The endosperm of Golden Rice (Oryza sativa) is yellow due to the accumulation of ?-carotene (provitamin A) and xanthophylls. The product of the two carotenoid biosynthesis transgenes used in Golden Rice results in Pale Yellow color.