- The tomato photomorphogenetic mutant, aurea, is deficient in phytochromobilin synthase for phytochrome chromophore biosynthesis. Muramoto, T., Kami, C., Kataoka, H., Iwata, N., Linley, P.J., Mukougawa, K., Yokota, A., Kohchi, T. Plant Cell Physiol. (2005)