裸子植物和被子植物花粉管生长机制的细胞学比较

为了比较裸子植物和被子植物花粉管生长机制,本研究利用激光共聚焦显微镜、全内反射荧光显微镜、透射电子显微镜观测比较了青杄、雪松、烟草和百合花粉管中FM4-64染色的时间变化特性和波动特性、囊泡移动速度、单位时间内细胞壁体积的增加,结果发现:与被子植物烟草和百合花粉管相比,裸子植物青杄和雪松花粉管中FM4-64荧光强度前期...

Cytological comparison of pollen tube growth between gymnosperms and angiosperms

In order to compare the mechanism underlying pollen tube growth in gymnosperms and angiosperms, laser confocal microscopy, total internal reflection fluorescence microscopy and transmission electron microscopy were used to observe the time variation and fluctuation characteristics of FM4-64 staining, the velocities of vesicles, and the increase of cell wall volume per unit time in pollen tubes of Picea wilsonii Mast., Cedrus deodara(Roxburgh) G. Don, Nicotiana tabacum L., Lilium longiflorum Thunb.. Our findings show that, compared with those of pollen tubes of Nicotiana tabacum L. and Lilium longiflorum Thunb., the fluorescence intensity of FM4-64 in the pollen tubes of Picea wilsonii Mast. and Cedrus deodara(Roxburgh) G. Don increased more slowly in the early stage and decreased more slowly in the late stage, indicating that the endocytosis and exocytosis rates of gymnosperm pollen tubes were significantly lower than those of angiosperms. Secondly, only 28% and 34% of the vesicles in gymnosperms’ pollen tubes were moving, and most of the vesicles moved slower than those in tobacco and lily pollen tubes, which revealed that the number of vesicles in gymnosperms’ pollen tubes that could move to the top for exocytosis per unit time was less than that in angiosperms’. However, the increased cell wall volume of Picea wilsonii Mast. and Cedrus deodara(Roxburgh) G. Don pollen tubes per unit time was larger than that of Nicotiana tabacum L. pollen tubes. These results suggest that the accumulation of cell wall precursors from vesicles contributes differently to the increase of pollen tube apical cell wall in gymnosperms and angiosperms.