Removal of Magnesium by Mg-dechelatase Is a Major Step in the Chlorophyll-Degrading Pathway in Ginkgo biloba in the Process of Autumnal Tints
Removal of Magnesium by Mg-dechelatase Is a Major Step in the Chlorophyll-Degrading Pathway in Ginkgo biloba in the Process of Autumnal Tints
复制标题
镁脱螯合酶去除镁是银杏秋色过程中叶绿素降解途径的一个主要步骤
DOI：
10.1515/znc-2000-11-1213
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
A. Kobayashi
中科院分区：
文献类型：
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作者：
L. Tang;A. Okazawa;E. Fukusaki;A. Kobayashi
秋天的色彩是最明显和迷人的自然现象之一，但在落叶树木叶绿素（Chl）的分解机制尚未完全阐明。本研究分析了银杏叶片秋转色过程中叶绿素相关化合物的组成，并测定了不同时期银杏叶片叶绿素降解酶的活性。在黄叶中只检测到脱镁叶绿素a（Pheo a，无镁叶绿素a），黄叶中镁脱螯合酶活性高于绿色叶。这些结果表明，镁从叶绿素a中的去除发生在银杏脱植酸之前。
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.