Phytoene desaturase (lycopene-forming) of a bacterial phytoene desaturase into transgenic tomatos increased the lycopene content without the need to alter several of the plants enzymes. This approach was later used in rice to increase its β-carotene content resulting in the Golden Rice project. Phytoene desaturase (lycopene-forming) Phytoene desaturase (lycopene-forming) (CrtI, "four-step phytoene desaturase") (, "15-cis-phytoene:acceptor oxidoreductase (lycopene-forming)") are enzymes found in archaea, bacteria and fungi that are involved in carotenoid biosynthesis. They catalyze the conversion of colorless 15-"cis"-phytoene into a bright red lycopene in a biochemical pathway called the poly-trans pathway. The same process in plants and cyanobacteria utilizes four separate enzymes in
Pigment called metamerism. Averaged measurements of pigment samples will only yield approximations of their true appearance under a specific source of illumination. Computer display systems use a technique called chromatic adaptation transforms to emulate the correlated color temperature of illumination sources, and cannot perfectly reproduce the intricate spectral combinations originally seen. In many cases, the perceived color of a pigment falls outside of the gamut of computer displays and a method called gamut mapping is used to approximate the true appearance. Gamut mapping trades off any one of lightness, hue, or saturation accuracy to render the color on screen, depending on