Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, CSIC, 18080 Granada, Spain.
Free Radic Biol Med. 2009 Dec 1;47(11):1632-9. doi: 10.1016/j.freeradbiomed.2009.09.012. Epub 2009 Sep 15.
Peroxisomes are organelles with an essentially oxidative metabolism that are involved in various metabolic pathways such as fatty acid beta-oxidation, photorespiration, and metabolism of reactive oxygen species (ROS) and reactive nitrogen species. These organelles are highly dynamic but there is little information about the regulation of, and the effects of environment on, peroxisome movement. In this work a stable Arabidopsis line expressing the GFP-SKL peptide targeted to peroxisomes was characterized. Peroxisome-associated fluorescence was observed in all tissues, including leaves (mesophyll and epidermal cells, trichomes, and stomata) and roots. The dynamics of peroxisomes in epidermal cells was examined by confocal laser microscope, and various types of movement were observed. The speed of movement differed depending on the plant age. Treatment of plants with CdCl(2) (100 microM) produced a significant increase in speed, which was dependent on endogenous ROS and Ca(2+), but was not related to actin cytoskeleton modifications. In light of the results obtained, it is proposed that the increase in peroxisomal motility observed in Arabidopsis plants could be a cellular mechanism of protection against the Cd-imposed oxidative stress. Other possible roles for the enhanced peroxisome movement in plant cell physiology are discussed.
过氧化物酶体是具有本质上氧化代谢的细胞器，参与各种代谢途径，如脂肪酸β-氧化、光呼吸以及活性氧（ROS）和活性氮（RNS）的代谢。这些细胞器具有高度的动态性，但关于过氧化物酶体运动的调节以及环境对其的影响的信息却很少。在这项工作中，我们对表达靶向过氧化物酶体的 GFP-SKL 肽的稳定拟南芥系进行了表征。在所有组织中，包括叶片（叶肉和表皮细胞、毛状体和气孔）和根中，都观察到与过氧化物酶体相关的荧光。通过共聚焦激光显微镜检查了表皮细胞中过氧化物酶体的动态，观察到了各种类型的运动。运动速度取决于植物的年龄。用 CdCl2（100 μM）处理植物会显著增加速度，这依赖于内源性 ROS 和 Ca2+，但与肌动蛋白细胞骨架的修饰无关。根据获得的结果，提出拟南芥植物中观察到的过氧化物酶体运动增加可能是一种细胞保护机制，可抵御 Cd 引起的氧化应激。还讨论了增强的过氧化物酶体运动在植物细胞生理学中的其他可能作用。
