Qu Xiaolu, Jiang Yuxiang, Chang Ming, Liu Xiaonan, Zhang Ruihui, Huang Shanjin
Center for Plant Biology, School of Life Sciences, Tsinghua University Beijing, China.
Key Laboratory of Plant Molecular Physiology, Institute of Botany - Chinese Academy of Sciences Beijing, China.
Front Plant Sci. 2015 Jan 8;5:786. doi: 10.3389/fpls.2014.00786. eCollection 2014.
Proper organization of the actin cytoskeleton is crucial for pollen tube growth. However, the precise mechanisms by which the actin cytoskeleton regulates pollen tube growth remain to be further elucidated. The functions of the actin cytoskeleton are dictated by its spatial organization and dynamics. However, early observations of the distribution of actin filaments at the pollen tube apex were quite perplexing, resulting in decades of controversial debate. Fortunately, due to improvements in fixation regimens for staining actin filaments in fixed pollen tubes, as well as the adoption of appropriate markers for visualizing actin filaments in living pollen tubes, this issue has been resolved and has given rise to the consensus view of the spatial distribution of actin filaments throughout the entire pollen tube. Importantly, recent descriptions of the dynamics of individual actin filaments in the apical region have expanded our understanding of the function of actin in regulation of pollen tube growth. Furthermore, careful documentation of the function and mode of action of several actin-binding proteins expressed in pollen have provided novel insights into the regulation of actin spatial distribution and dynamics. In the current review, we summarize our understanding of the organization, dynamics, and regulation of the actin cytoskeleton in the pollen tube.
肌动蛋白细胞骨架的正确组织对花粉管生长至关重要。然而，肌动蛋白细胞骨架调节花粉管生长的精确机制仍有待进一步阐明。肌动蛋白细胞骨架的功能由其空间组织和动态变化决定。然而，早期对花粉管顶端肌动蛋白丝分布的观察相当令人困惑，导致了数十年的争议性辩论。幸运的是，由于固定花粉管中肌动蛋白丝染色固定方案的改进，以及在活花粉管中可视化肌动蛋白丝的适当标记物的采用，这个问题已经得到解决，并产生了关于整个花粉管中肌动蛋白丝空间分布的共识观点。重要的是，最近对顶端区域单个肌动蛋白丝动态变化的描述扩展了我们对肌动蛋白在调节花粉管生长中功能的理解。此外，对花粉中表达的几种肌动蛋白结合蛋白的功能和作用模式的仔细记录为肌动蛋白空间分布和动态变化的调节提供了新的见解。在本综述中，我们总结了我们对花粉管中肌动蛋白细胞骨架的组织、动态变化和调节的理解。
