【摘要】 【目的】在显花植物生殖过程中花粉萌发和花粉管生长起着至关重要的作用,这一过程受许多因素的影响,其中钙调素类似蛋白（calmodulin-like proteins,CMLs）通过直接或间接的作用机制调控花粉萌发及花粉管生长。然而,迄今人们对CMLs的功能研究尚少。本文旨在初步了解CMLs蛋白在花粉竞争优势中的作用,为深入探究CMLs蛋白在植物花粉竞争优势中的分子机制奠定理论基础。【方法】本文主要通过对参与调控花粉萌发以及花粉管生长过程的CMLs蛋白的结构、表达水平、细胞定位及其作用机理的归纳,结合不同植物中出现的花粉竞争现象,综合分析并总结国内外相关研究结果。【结果】CMLs蛋白约有4个保守的EF手性结构域,当CMLs蛋白结合Ca²⁺时,其构象发生变化,增强与下游受体蛋白的结合能力,并启动Ca²⁺依赖的级联信号放大效应,引起花粉管中Ca²⁺的浓度变化,影响从萌发孔到花粉管顶端Ca²⁺浓度梯度的形成,从而调控花粉管的正常生长。CMLs蛋白的表达还可以影响Mg²⁺、NO等离子的浓度变化,影响Ca²⁺与EF手性结构域的结合及花粉管生长的导向。不同CMLs蛋白具有不同生理功能,其中参与花粉萌发及花粉管生长的CMLs蛋白主要在植物花器官中表达;部分显花植物在受精过程中,不同倍性花粉之间可能由于基因组大小或者营养物质含量的差异,导致萌发率及生长速率的不同。【结论】CMLs蛋白可能通过在不同倍性花粉中的差异表达,影响花粉在体内萌发的进程,使其在某一时期表现出竞争优势。更多还原

【Abstract】 [Objective] Pollen germination and pollen tube growth play a critical role in reproductive process of flowering plants. Pollen germination and pollen tube growth is regulated directly or indirectly by many factors, such as calmodulin-like proteins（CMLs）. However, very little research has focused on the function of CMLs till now. The aim of this paper is to reveal the role of CML proteins in the competitive advantage of pollen, and to provide a theoretical foundation for further exploring the molecular mechanism of CMLs in plant pollen competitive advantage. [Method] This paper comprehensively summarizes the structure, expression level, cell localization and mechanisms of CMLs proteins involved in the regulation of pollen germination and pollen tube growth, and analyzes the pollen competition phenomena in different plants. [Result] There were about four conserved EF-hand domains in CMLs. When CMLs bind to Ca²⁺, its conformation changes enhanced its binding ability to downstream receptor proteins, and initiated Ca²⁺dependent cascade signal amplification effect, which resulted in changes in Ca²⁺ concentration in pollen tube and influenced the formation of Ca²⁺ concentration gradient from germination aperture to the top of pollen tube, thus regulating the normal growth of pollen tube. The expression of CML proteins can also affect the concentration of Mg²⁺, NO and the binding of Ca²⁺ to EF-hand domains and the orientation of pollen tube growth. Different CML proteins had different physiological functions. Among them, CML proteins involved in pollen germination and pollen tube growth were mainly expressed in plant floral organs. During fertilization of some flowering plants, different ploidy pollens may have different germination rates and growth rates due to differences in genome size or nutrient content. [Conclusion] CMLs proteins may affect the process of pollen germination in vivo by differentially expressing in different ploidy pollens, and make them show competitive advantage in a certain period of time.更多还原