Kinetic of lipoquinone synthesis in etiolated Raphanus seedlings in continuous far-red and white light

Abstract

Continuous far-red light changes the lipoquinone metabolism of etioplasts from Raphanus seedlings to that of chloroplasts in much the same way as does white light. In contrast to darkness far-red induces the formation of more total plastoquinone-9 than total α-tocopherol. The oxidized quinone forms are enriched to a higher degree than in the Bark. Far-red enhances the formation of vitamin K 1 and decreases the level of the second naphthoquinone vitamin ≪K≫. The results indicate that active phytochrome P fr in its excited state (high irradiance response) regulates the lipoquinone synthesis related to thylakoid formation.