Mathur Jaideep, Mathur Neeta, Hülskamp Martin
Botanical Institute III, University of Köln, Gyrhofstrase 15, 50931 Cologne, Germany.
Plant Physiol. 2002 Mar;128(3):1031-45. doi: 10.1104/pp.011018.
Peroxisomes were visualized in living plant cells using a yellow fluorescent protein tagged with a peroxisomal targeting signal consisting of the SKL motif. Simultaneous visualization of peroxisomes and microfilaments/microtubules was accomplished in onion (Allium cepa) epidermal cells transiently expressing the yellow fluorescent protein-peroxi construct, a green fluorescent protein-mTalin construct that labels filamentous-actin filaments, and a green fluorescent protein-microtubule-binding domain construct that labels microtubules. The covisualization of peroxisomes and cytoskeletal elements revealed that, contrary to the reports from animal cells, peroxisomes in plants appear to associate with actin filaments and not microtubules. That peroxisome movement is actin based was shown by pharmacological studies. For this analysis we used onion epidermal cells and various cell types of Arabidopsis including trichomes, root hairs, and root cortex cells exhibiting different modes of growth. In transient onion epidermis assay and in transgenic Arabidopsis plants, an interference with the actin cytoskeleton resulted in progressive loss of saltatory movement followed by the aggregation and a complete cessation of peroxisome motility within 30 min of drug application. Microtubule depolymerization or stabilization had no effect.
利用带有由SKL基序组成的过氧化物酶体靶向信号的黄色荧光蛋白,在活植物细胞中观察到了过氧化物酶体。在瞬时表达黄色荧光蛋白-过氧化物酶体构建体、标记丝状肌动蛋白丝的绿色荧光蛋白-mTalin构建体以及标记微管的绿色荧光蛋白-微管结合域构建体的洋葱(葱属)表皮细胞中,实现了过氧化物酶体与微丝/微管的同时观察。过氧化物酶体与细胞骨架成分的共观察显示,与动物细胞的报道相反,植物中的过氧化物酶体似乎与肌动蛋白丝而非微管相关。药理学研究表明过氧化物酶体运动基于肌动蛋白。为了进行此分析,我们使用了洋葱表皮细胞以及拟南芥的各种细胞类型,包括毛状体、根毛和表现出不同生长模式的根皮层细胞。在瞬时洋葱表皮试验和转基因拟南芥植物中,对肌动蛋白细胞骨架的干扰导致跳跃运动逐渐丧失,随后过氧化物酶体聚集,并在药物应用后30分钟内完全停止运动。微管解聚或稳定化没有影响。