Department of Biosciences, University of Milan , Milan, Italy.
Institute of Biophysics, National Research Council and Fondazione Bruno Kessler , Trento, Italy.
Front Plant Sci. 2015 Feb 10;6:51. doi: 10.3389/fpls.2015.00051. eCollection 2015.
In plants, actin filaments have an important role in organelle movement and cytoplasmic streaming. Otherwise microtubules (MTs) have a role in restricting organelles to specific areas of the cell and in maintaining organelle morphology. In somatic plant cells, MTs also participate in cell division and morphogenesis, allowing cells to take their definitive shape in order to perform specific functions. In the latter case, MTs influence assembly of the cell wall, controlling the delivery of enzymes involved in cellulose synthesis and of wall modulation material to the proper sites. In angiosperm pollen tubes, organelle movement is generally attributed to the acto-myosin system, the main role of which is in distributing organelles in the cytoplasm and in carrying secretory vesicles to the apex for polarized growth. Recent data on membrane trafficking suggests a role of MTs in fine delivery and repositioning of vesicles to sustain pollen tube growth. This review examines the role of MTs in secretion and endocytosis, highlighting new research cues regarding cell wall construction and pollen tube-pistil crosstalk, that help unravel the role of MTs in polarized growth.
在植物中，肌动蛋白丝在细胞器运动和细胞质流中起着重要作用。而微管（MTs）则在将细胞器限制在细胞的特定区域和维持细胞器形态方面发挥作用。在体细胞中，MT 还参与细胞分裂和形态发生，使细胞获得确定的形状，以执行特定的功能。在后一种情况下，MT 影响细胞壁的组装，控制参与纤维素合成的酶和细胞壁调节物质的输送到适当的位置。在被子植物花粉管中，细胞器运动通常归因于肌动球蛋白系统，其主要作用是在细胞质中分配细胞器，并将分泌小泡运送到顶端以进行极化生长。最近关于膜运输的研究数据表明，MT 在小泡的精细输送和重新定位中发挥作用，以维持花粉管的生长。本文综述了 MT 在分泌和内吞作用中的作用，强调了有关细胞壁构建和花粉管-柱头相互作用的新研究线索，这些线索有助于阐明 MT 在极化生长中的作用。
