中文摘要：

极化的尖端生长是在许多优核质的一个基本细胞的过程。在这研究，我们检验了在 Arabidopsis 的在花粉尖端生长期间的到泡运输的肌动朊细胞骨架和它的关系的动态重构。我们发现从顶端的膜发源的肌动朊细丝形成由排列肌动朊与不同分布在外皮和内部细胞质的细丝绑的纵组成的专业化结构。用在联合与的基于肌动朊的药理学处理和基因异种捆牢(在 photobleaching 以后的荧光恢复) 在花粉试管的生长领域以内设想泡的运输的技术，我们证明外皮的肌动朊细丝便于尖端病房泡运输。我们也发现内部顶端的肌动朊细丝阻止泡的向后的运动，因此保证足够的泡在花粉试管尖端积累支持花粉试管的快速的生长。外皮、内部的顶端的肌动朊细丝的组合效果完美地在花粉试管尖端解释转换 V 锥形的泡分发模式的产生。当花粉试管转弯时，在面对的方面的顶端的肌动朊细丝经历 depolymerization 和聚合到使适应向新生长方向的顶端的肌动朊结构。重构的这肌动朊先于泡累积并且在试管形态学变化。因此，我们的学习在快速、方向性的花粉试管生长期间提供新卓见进在肌动朊动力学和泡运输之间的功能的关系。

英文摘要：

Polarized tip growth is a fundamental cellular process in many eukaryotes. In this study, we examined the dynamic restructuring of the actin cytoskeleton and its relationship to vesicle transport during pollen tip growth in Arabidopsis. We found that actin filaments originating from the apical membrane form a specialized structure consisting of longitudinally aligned actin bundles at the cortex and inner cytoplasmic fila- ments with a distinct distribution. Using actin-based pharmacological treatments and genetic mutants in combination with FRAP （fluorescence recovery after photobleaching） technology to visualize the transport of vesicles within the growth domain of pollen tubes, we demonstrated that cortical actin filaments facilitate tip-ward vesicle transport. We also discovered that the inner apical actin filaments prevent backward movement of vesicles, thus ensuring that sufficient vesicles accumulate at the pollen tube tip to support the rapid growth of the pollen tube. The combinatorial effect of cortical and internal apical actin filaments perfectly explains the generation of the inverted ＂V＂ cone-shaped vesicle distribution pattern at the pollen tube tip. When pollen tubes turn, apical actin filaments at the facing side undergo depolymerization and repolymerization to reorient the apical actin structure toward the new growth direction. This actin restructuring precedes vesicle accumulation and changes in tube morphology. Thus, our study provides new insights into the functional relationship between actin dynamics and vesicle transport during rapid and directional pollen tube growth.