Biology Department, Texas A&M University, 3258 TAMU, College Station, TX 77843, USA.
Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
J Exp Bot. 2017 Jul 10;68(15):4075-4087. doi: 10.1093/jxb/erx243.
Plasmolysis of hypocotyl cells of transgenic Arabidopsis thaliana and Nicotiana benthamiana diminishes the dynamics of the remodeling of the endoplasmic reticulum (ER) in the central protoplast, namely that withdrawn from the cell wall, and more persistent cisternae are formed, yet little change in the actin network in the protoplast occurs. Also, protein flow within the ER network in the protoplast, as detected with fluorescence recovery after photobleaching (FRAP), is not affected by plasmolysis. After plasmolysis, another network of strictly tubular ER remains attached to the plasma membrane-wall interface and is contained within the Hechtian strands and reticulum. FRAP studies indicate that protein flow within these ER tubules diminishes. Actin is largely absent from the Hechtian reticulum and the ER becomes primarily associated with altered, branched microtubules. The smaller volume of the central protoplast is accompanied by decreased movement rates of tubules, cisternae, and spheroid organelles, but this reduced movement is not readily reversed by the increase in volume that accompanies deplasmolysis.
拟南芥和本氏烟的下胚轴细胞的质壁分离会减少中央原生质体中内质网（ER）重塑的动态性，即从细胞壁中撤出的内质网，并且会形成更多持久的潴泡，但原生质体中的肌动蛋白网络几乎没有变化。此外，用荧光恢复后漂白（FRAP）检测到的原生质体中 ER 网络内的蛋白质流动不受质壁分离的影响。质壁分离后，另一个严格管状的 ER 网络仍然附着在质膜-细胞壁界面上，并包含在 Hechtian 链和网中。FRAP 研究表明，这些 ER 管内的蛋白质流动减少。肌动蛋白主要不存在于 Hechtian 网中，内质网主要与改变的、分支的微管相关联。中央原生质体的较小体积伴随着小管、潴泡和球形细胞器的运动速度降低，但这种减少的运动在质壁分离伴随的体积增加时不容易逆转。
