Kinetic of Lipoquinone and Pigment Synthesis during Red Light-Induced Thylakoid Formation in Etiolated Barley Seedlings

Abstract

Abstract Red light induces in etioplasts of dark-grown barley seedlings (H ordeum vulgare L.) parallel to the formation of chlorophyll an increased synthesis of carotenoids, lipophilic benzoquinones and of vitamin K1. 1. Among the carotenoids red light initiates an enhanced synthesis of β-carotene, lutein, violaxanthine and neoxanthine whereas the pools of zeaxanthine and antheraxanthine are decreased. 2. The formation of plastoquinone-9, vitamin K1 and a-tocoquinone is more enhanced than that of a-tocopherol. 3. The red light-induced changes of carotenoid and lipoquinone metabolism are similar in a qualitative sense to those obtained under continuous far-red, white or blue light. 4. In contrast to blue light, red light induces in the first hours of illumination a lower rate of chlorophyll and vitamin K1 formation. There are also differences in the ratios of the individual pigments and lipoquinones throughout the greening period.