油杉花粉萌发与花粉管细胞骨架系统的研究

应用免疫荧光标记法结合激光扫描共聚焦显微镜术对油杉花粉管中的微管、微丝骨架进行观察.结果表明:伸长的花粉管大致可分为3个区,即位于顶端的管细胞区、体细胞区和其后的退化区;花粉管中微管与微丝的分布样式不同;微管骨架主要分布于管细胞区和体细胞区,而退化区的微管较稀疏；管细胞区内微管呈网状结构,微管一直延伸至花粉管极顶端;体细胞具独立的微管系统.花粉管内微丝骨架呈轴向排列于整个花粉管,自花粉粒内一直延伸至花粉管顶端,粗微丝束几乎平行于花粉管的长轴.本研究结果为进一步研究微管与微丝骨架系统在油杉花粉管顶端极性生长中的作用提供依据.

Pollen Germination and Cytoskeletal Organization in Pollen Tube of Keteleeria fortunei

The cytoskeletal organization in pollen tube of Keteleeria fortunei was investigated using a confocal laser scanning microscope after immunolabeling for microtubules and rhodamine-phalloidin fluorescence labeling for microfilaments. The K. fortunei mature pollen grain contained two degenerated prothallial cells, a body cell, a stalk cell, and a tube cell. In the elongating pollen tubes, three cytological zones were identified, which were the tube cell zone, the body cell zone and the deterioration zone. The results of confocal microscopy showed that the distribution pattern of microtubules within pollen tubes was distinct from that of microfilaments. An enriched microtubules network was present in the tube cell zone and the body cell zone. However, the deterioration zone had poor microtubules. In the tube cell zone, microtubules formed an ordered network and extended towards the pollen tube tip. The body cell possessed a separate dense meshwork of microtubules. The microfilaments formed a longitudinal array within the pollen tube, which extended from the pollen grain throughout the tube. There was also a network of microfilaments at the tube tip. The cytoskeletal function in conifer pollen tube growth was discussed in this present paper. It was also suggested that the microtubule cytoskeleton within the K. fortunei pollen tube might play key roles in determining the shapes of tube cell and body cell, and maintaining the polarity of tip growth, while the microfilament cytoskeleton was responsible for pollen tube growth and was involved in the movement of body cell. It might provide an important foundation for further studies on the cytoskeletal function in K. fortunei pollen tube growth.