Paradez Alex, Wright Amanda, Ehrhardt David W
Department of Plant Biology, Carnegie Institution, 260 Panama Street, Stanford, California 94305, USA.
Curr Opin Plant Biol. 2006 Dec;9(6):571-8. doi: 10.1016/j.pbi.2006.09.005. Epub 2006 Sep 28.
Plant cell cortical microtubule arrays attain a high degree of order without the benefit of an organizing center such as a centrosome. New assays for molecular behaviors in living cells and gene discovery are yielding insight into the mechanisms by which acentrosomal microtubule arrays are created and organized, and how microtubule organization functions to modify cell form by regulating cellulose deposition. Surprising and potentially important behaviors of cortical microtubules include nucleation from the walls of established microtubules, and treadmilling-driven motility leading to polymer interaction, reorientation, and microtubule bundling. These behaviors suggest activities that can act to increase or decrease the local level of order in the array. The SPIRAL1 (SPR1) and SPR2 microtubule-localized proteins and the radial swollen 6 (rsw-6) locus are examples of new molecules and genes that affect both microtubule array organization and cell growth pattern. Functional tagging of cellulose synthase has now allowed the dynamic relationship between cortical microtubules and the cell-wall-synthesizing machinery to be visualized, providing direct evidence that cortical microtubules can organize cellulose synthase complexes and guide their movement through the plasma membrane as they create the cell wall.
植物细胞皮层微管阵列在没有诸如中心体这样的组织中心的情况下达到高度有序。用于活细胞分子行为和基因发现的新检测方法正在深入了解无中心体微管阵列的形成和组织机制，以及微管组织如何通过调节纤维素沉积来改变细胞形态。皮层微管令人惊讶且可能重要的行为包括从已有的微管壁上成核，以及踏车运动驱动的运动，导致聚合物相互作用、重新定向和微管束集。这些行为表明存在一些活动，可增加或降低阵列中局部的有序程度。SPIRAL1（SPR1）和SPR2微管定位蛋白以及径向肿胀6（rsw - 6）位点是影响微管阵列组织和细胞生长模式的新分子和基因的例子。纤维素合酶的功能标记现在使得皮层微管与细胞壁合成机制之间的动态关系得以可视化，提供了直接证据表明皮层微管可以组织纤维素合酶复合物，并在它们构建细胞壁时引导其通过质膜移动。
