Tang L, Okazawa A, Fukusaki E, Kobayashi A
Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Japan.
Z Naturforsch C J Biosci. 2000 Nov-Dec;55(11-12):923-6. doi: 10.1515/znc-2000-11-1213.
Autumnal tints are one of the most manifest and fascinating natural phenomena, but the mechanism of chlorophyll (Chl)-breakdown in deciduous trees has not been fully elucidated. In this study, we analyzed the composition of Chl-related compounds and determined the activities of initial Chl-degrading enzymes in Ginkgo leaves at various stages in the process of autumnal coloring. Only pheophytin a (Pheo a, Mg-free Chl a) was detected in yellow leaves by HPLC analysis, and the activity of Mg-dechelatase in yellow leaves was found to be higher than in green leaves. These findings showed that the removal of magnesium from Chl a occurred in advance of dephytylation in the Ginkgo.
秋色是最明显且迷人的自然现象之一，但落叶树中叶绿素（Chl）分解的机制尚未完全阐明。在本研究中，我们分析了银杏叶在秋季变色过程中各个阶段与叶绿素相关化合物的组成，并测定了初始叶绿素降解酶的活性。通过高效液相色谱分析，在黄叶中仅检测到脱镁叶绿素a（Pheo a，无镁叶绿素a），并且发现黄叶中镁脱螯合酶的活性高于绿叶。这些发现表明，在银杏中，叶绿素a的镁去除发生在脱植基作用之前。
