Pectin methylesterases from poplar cambium and inner bark: Localization, properties and seasonal changes
Pectin methylesterases from poplar cambium and inner bark: Localization, properties and seasonal changes
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DOI：
10.1007/s004250050104
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发表时间：
1997-05-01
期刊：
影响因子：
4.3
通讯作者：
Goldberg, R
中科院分区：
文献类型：
--
作者：
Guglielmino, N;Liberman, M;Goldberg, R
在欧美杨形成层衍生物分化的早期事件的研究过程中，果胶甲基酯酶（PME，EC 3.1.1.11）亚型的模式的季节性变化如下。在休眠期，细胞壁提取物主要含有碱性异构体，M-r在55 kDa左右，最适PPI在5.6 - 6.0之间;在高分生活性期，中性异构体占主导地位，M-r在35 kDa左右，最适pH在6.0 - 6.6之间。在活跃的形成层的初始和直接衍生物，酶免疫定位专门在dictyosomes。在较老的细胞中，它们既存在于高尔基体中，也存在于壁连接处。这些结果表明，中性PMEs向壁的输出可能被认为是形成层衍生物分化的早期标志。
In the course of a study on the early events of cambial derivative differentiation in Populus x euramericana, seasonal changes in the pattern of pectin methylesterase (PME, EC 3.1.1.11) isoforms were followed. During the resting season, cell wall extracts contained mainly alkaline isoforms with an M-r around 55 kDa and optimal PPI between 5.6 and 6.0, Neutral isoforms with an M-r around 35 kDa and optimal pH between 6.0 and 6.6 predominated in the extracts during the period of high meristematic activity. In the active cambial initials and in their immediate derivatives, the enzymes were immunolocalized exclusively in the dictyosomes. In older cells, they were present both in dictyosomes and in wall junctions. These results indicate that exportation of neutral PMEs towards the walls might be considered as an early marker of differentiation in cambial derivatives.