Analysis of the transport of generative cells in pollen tubes of higher plants

已有研究表明，肌动蛋白细胞骨架参与了高等植物花粉管中生殖细胞的运输。我们研究了肌球蛋白在这种运输中的作用，并试图从百合花粉管中鉴定肌球蛋白1。肌球蛋白参与生殖细胞的运输。肌球蛋白抑制剂2，3-丁二酮单肟(BDM)可逆地抑制百合花粉管中生殖细胞和营养核的胞质流动和运输。BDM处理改变了生殖细胞和营养核的长度和形态。经BDM处理的花粉管中肌动蛋白细丝的组织只有轻微的扰动，这表明肌球蛋白实际上负责生殖细胞运输的动力的产生。负责生殖细胞运输的肌球蛋白的鉴定从百合花粉管中分离到一种由120 kDa重链组成的肌球蛋白。这条120 kDa的重链具有不同于170 kDa肌球蛋白重链的抗原性，肌球蛋白重链参与高等植物细胞的细胞质流动。该肌球蛋白被认为是生殖细胞或营养核运输的候选分子马达。

It has been suggested that actin cytoskeleton is involved in the transport of generative cells In pollen tubes of higher plants. We studies the involvement of myosin in this transport and tried to identify the myosin from lily pollen tubes1. Involvement of myosin in the transport of generative cells. 2,3-butanedione monoxime (BDM), a myosin inhibitor, reversibly suppressed the cytoplasmic streaming and the transport of both generative cells and vegetative nuclei in lily pollen tubes. The length and morphology of generative cells and vegetative nuclei were altered by the treatment with BDM. The organization of actin-filaments in the treated pollen tubes with BDM was only slightly perturbed, suggesting that myosin is actually responsible for the generation of motive force for the transport of generative cells.2. Identification of myosin responsible for the transport of generative cells A myosin composed of 120-kDa heavy chain was isolated from lily pollen tubes. An antigenicity of this 120-kDa heavy chain was different from the 170-kDa myosin heavy chain which is involved in the cytoplasmic streaming in higher plant cells. It was considered that this myosin is a candidate of molecular motor for the transport of generative cells or vegetative nuclei.