裸子植物和被子植物花粉管生长机制的细胞学比较

郑茂钟*,林 立,叶宏萌,华伟平

裸子植物和被子植物花粉管生长机制的细胞学比较

郑茂钟*,林  立,叶宏萌,华伟平

(1.武夷学院生态与资源工程学院,福建武夷山354300;2.福建省生态产业绿色技术重点实验室,福建武夷山354300 )

   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、囊泡运输速度、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荧光强度前期增加速度慢,后期降低速度慢,表明裸子植物花粉管的胞吞和胞吐速率明显低于被子植物花粉管。其次,裸子植物花粉管青杄和雪松花粉管中分别只有28%和34%的囊泡在移动,且多数囊泡移动速度小于被子植物烟草和百合花粉管,揭示了裸子植物花粉管中单位时间内能移动到顶端进行胞吐运动的囊泡的数量要少于被子植物的。然而裸子植物青杄和雪松花粉管单位时间内需要增加的细胞壁体积大于被子植物烟草花粉管。这些结果暗示着来自囊泡的细胞壁前体物质的积累对裸子植物和被子植物花粉管顶端细胞壁的增加其贡献是不同的。

关键词   花粉管;被子植物;裸子植物;胞吐;胞吞;生长机制

中图分类号:Q 256;Q 336;Q 274     

文献标识码:Adoi:10.3969/j.issn.1000-6281.2022.01.009

 

Cytological comparison of pollen tube growth between gymnosperms and angiosperms

ZHENG Mao-zhong 1, 2,  LIN Li1, 2, YE Hong-meng1, 2, HUA Wei-ping 1, 2

(1.College of Ecology and Resource Engineering, Wuyi University Wuyishan 354300;2.Fujian Provincial Key Laboratory of Eco-indurstrial Green Technology, Wuyi University Wuyishan 354300, China)

Abstract  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 ofNicotiana 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.

Keywords   pollen tube; angiosperm; gymnosperm; exocytosis; endocytosis; growth mechanism

 

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