Abstract
Rice phytochrome family is comprised of three members, phyA, phyB and phyC. In order to obtain the information about the fundamental characters of rice phytochromes, we have analyzed the expression levels and patterns of these three phytochromes in rice seedlings as well as different tissues under different light conditions. In dark-grown seedlings, PHYA protein was dominant over other two phytochromes. In contrast, PHYB was dominant in light-grown seedlings. PHYA was highly light-labile, and the protein level was reduced to less than one tenth after 8 h irradiation. PHYB was relatively light-stable, only showing a slight reduction by 8 h light treatment. We also analyzed phytochrome levels in various tissues of 6-day old dark-grown seedlings. PHYA was highest in coleoptiles, and relatively lower in roots and leaves, whereas PHYB and PHYC were highest in leaves. Light stability of three phytochromes was different among different tissues.
