Biologisches Institut II der Universität, Schaenzlestraße 1, D-7800, Freiburg i.Br., Federal Republic of Germany.
Planta. 1985 Jun;164(3):390-5. doi: 10.1007/BF00402951.
The composition of coloured carotenoids in the milo shoot was investigated quantitatively (high performance liquid chromatography) during light-mediated plastidogenesis, including the time span of 'photodelay' as caused by medium and high light fluxes. It was found that as long as only the far-red-absorbing form of phytochrome operates, the carotenoid pattern remains virtually the same as in complete darkness (violaxanthin and lutein as major constituents, traces of β-carotene). On the other hand, the pattern changes dramatically in white or red light with increasing amounts of chlorophyll (lutein and β-carotene dominate, β-carotene showing the strongest relative increase). Photodelay during the early phase of plastidogenesis affects the carotenoid composition strongly. Increase of neoxanthin, violaxanthin and β-carotene contents are diminished while lutein accumulation proves resistant towards chlorophyll-mediated photoinhibition. The photodelay can be diminished by an appropriate light pretreatment. The data indicate that light-mediated control over carotenoid accumulation is exerted at three levels: i) a coarse control through phytochrome, ii) fine tuning in connection with chlorophyll accumulation, iii) stabilization of holocomplexes against photodecomposition.
米罗芽在光介导的质体发生过程中，定量研究了有色类胡萝卜素的组成（高效液相色谱法），包括中、高光通量引起的“光延迟”时间范围。结果发现，只要远红光吸收型的光敏色素起作用，类胡萝卜素的模式就与完全黑暗中几乎相同（玉米黄质和叶黄素为主要成分，β-胡萝卜素痕迹）。另一方面，在白光或红光中，随着叶绿素含量的增加，模式变化剧烈（叶黄素和β-胡萝卜素占主导地位，β-胡萝卜素的相对增加最强）。质体发生早期的光延迟强烈影响类胡萝卜素的组成。新黄质、玉米黄质和β-胡萝卜素含量的增加减少，而叶黄素的积累对叶绿素介导的光抑制具有抗性。适当的光预处理可以减少光延迟。这些数据表明，光介导的类胡萝卜素积累的控制作用于三个水平：i）通过光敏色素进行粗控制，ii）与叶绿素积累相关的微调，iii）稳定完整复合物以防止光降解。
