Phytochrome Photoconversion in Vivo

Publisher Website
Google Scholar
Abstract
The measured rates of phytochrome photoconversion in vivo, in etiolated cabbage (Brassica oleraea L.) seedlings and cucumber (Cucumis sativus L.) cotyledons, under blue, red, and far red irradiation, are significantly different from those predicted on the basis of the spectral photon flux distributions of the light sources and optical parameters of purified pytochrome. The geometrical relationships between the light source and the irradiated sample affect the rate of phytochrome photoconversion, which is significantly faster in cabbage seedling laying flat on white, wet filter paper than in seedlings in a vertical position. Light reflected from the white filter paper on the bottom of the dish contributed significantly to phytochrome photoconversion. Substituting the white filter paper with a less reflective black one results in a significant decrease of the rate of phytochrome photoconversion in cucumber cotyledons.