用非固定的荧光探针方法观察紫萼花粉管肌动蛋白纤丝的形式

用非固定的、二甲基亚砜作为渗透剂的、异硫氰四甲基罗丹明标记的鬼笔环肽染色方法,观察了紫萼(Hosta caerulea Tratt.)未萌发的花粉粒及不同生长时期的花粉管中的肌动蛋白纤丝的形式。显示未萌发的花粉粒中具有结晶状的梭状体,为肌动蛋白的一种贮藏形式。花粉萌发时,这种梭状体转移到短的花粉管中,逐渐松解、分支和形成肌动蛋白纤丝交错的网络。在花粉管迅速生长和达到一定长度时,肌动蛋白纤丝形成以与花粉管长轴平行的细丝占优势的网络系统,这是在大多数情况中紫萼花粉管典型的肌动蛋白纤丝的形式。在某些条件下,在花粉管接近顶端的前部,肌动蛋白纤丝可集合成长的粗束,这种粗束也常有分支和并合。肌动强白纤丝一直分布到花粉管的末端。讨论了研究肌动蛋白纤丝的非固定方法的重要性和进一步研究花粉管肌动蛋白纤丝值得注意的问题。

VISUALIZATION OF ACTIN FILAMENT PATTERNS IN POLLEN TUBES OF HOSTA CAERULEA TRATT.WITH A NON-FIXATION AND TRITC-PHALLOIDIN METHOD

Actin filament patterns during pollen germination in Hosta caerulea Tratt.were visua- lized with a simple method in which there was no pre-fixation,with dimethylsulphoxide (DMSO)as a permeabilising agent and staining with TRITC-Phalloidin.The cytoplasm of the vegetative cell of the ungerminated pollen grain contained numerous crystalline fusiform bodies to constitute a storage form of actin.These bodies were transferred to the emerging pollen tube after the germination of the pollen grain.Following the growth of pollen tube, the fusiform bodies were gradually dissociated,branched,slenderized and formed a cross-link- ed actin network.During the further growth of the pollen tube,the preponderance of long- itudinally-oriented thin actin filaments with some anastomoses to form a more complex net- work present always in the long pollen tube.This was the typical pattern of actin filaments in most cases.In some conditions,actin filaments were assembled to form thick actin cables near the proximate part of the pollen tube tip.The branching and connecting of the cables were probably also seen in some parts.Actin filaments were always entering to the apical region of a tube tip.The significance of the non-fixation and fluorescence-phalloidin(F1-Ph)me- thod and the problems in the future studies are discussed.