高等植物需要花粉管传递精细胞到雌配子体完成双受精过程，故正常的花粉萌发及花粉管生长对于被子植物有性生殖是至关重要的。细胞骨架在花粉萌发和花粉管极性生长过程中起着重要作用，其结构和动态变化受很多微丝/微管结合蛋白精准调控。KCH是一类植物所特有的驱动蛋白，除保守的马达结构域外，还含有一个结合微丝的调宁蛋白同源域。然而，目前有关KCH家族成员在花粉管生长中的生理功能还未见报道。申请人已有的研究结果发现，缺失花粉特异表达的KCH（R-KCH）突变体植株产生了明显的花粉管生长减慢、生长方向改变、种子败育等表型，暗示着R-KCHs在植物生殖相关生理活动中起着非常重要的作用。本项目拟系统研究R-KCHs在植物生殖相关生理活动中的功能，探索它们参与调控微丝/微管结构和动态变化的机理，旨在阐明KCH在植物演化中的重要性及其生物学意义，为揭示细胞骨架参与调控花粉管极性生长的机理研究提供新的理论依据。

Pollen tube translates sperm cell to ovary for double fertilization, and normal pollen tube growth is vital for plant sexual reproduction. The cytoskeleton plays critical roles in pollen germination and pollen tube tip growth，and its structure and dynamic are precisely regulated by actin binding proteins (ABPs) and microtubule-associated proteins (MAPs). KCHs are plant-unique kinesin, containing conserved motor domain and a Calponin-homology domain. However, the function of KCHs in pollen tube growth is remain unknown. Here, we show that four Arabidopsis thaliana KCHs preferentially expressed in pollen grains and pollen tubes were named as reproductive KCH (R-KCHs), and R-KCHs loss-of-function inhibits pollen tube growth, and leads to aberrant pollen tube growth patterns and morphologies, and fewer fertilization events, indicating that R-KCHs play an important role in plant reproductive process. Thus, our goal is to understand the mechanism of R-KCHs playing in pollen tube tip growth via regulatingcytoskeleton structure and dynamic. This research not only helps to reveal the molecular mechanism of pollen tube tip growth, but also has important theoretical value in plant reproductive field.