Patterns of luminescence in transgenic plants transformed with the PHYA:LUC construct. A through C, Images from a 7-d-old light-grown seedling. A, Overexposed luminescence image, the arrows point at the lateral root and primary root tip. B, Luminescence image. C, Reflected light image. D through F, Images from a 7-d-old dark-grown seedling. D, Overexposed luminescence image, the arrow points to the root tip. E, Luminescence image. F, Reflected light image.