凤眼莲柱头细胞中肌动蛋白纤丝分布形式的荧光显微观察

FLUORESCENCE MICROSCOPIC OBSERVATIONS ON THE DISTRIBUTION PATTERNS OF ACTIN FILAMENTS IN STIGMA CELLS OF EICHHORNIA CRASSIPES

以异硫氰酸荧光素-鬼笔环肽为探针对未经固定的花期凤眼莲(Eichhornia crassipes (Mort)Solms)柱头细胞内肌动蛋白纤丝的存在形式进行荧光显微观察。结果表明,在外延呈指状的柱头乳突细胞中肌动蛋白具有明显的区域性分布特征:在基部呈具强烈荧光的梭状体散在分布;中段富含细胞质,大量粗细不等的肌动蛋白纤丝以大体平行于纵轴的方向构成密集的网络,并渐次集束向顶部延伸;顶端区肌动蛋白纤丝分布稀疏,且常出现弥散状特异荧光。进而发现,周质层中存在着由极细纤丝相互平行或局部相交形成的网络,自基部向顶端呈螺旋状分布。联系柱头细胞中活跃的原生质流动、溶质从细胞基部大量向上运转与在顶端分泌外排以及维持指状细胞周质层的结构完整与稳定,付论了肌动蛋白纤丝分布和存在形式与这些生理活动间的可能联系。

The distribution patterns of actin filaments in the non-fixed stigma of Eichhornia crassipes (Mart) Solms were examined with fluorescence microscopy by using FITC-phalloidin as fluores- cence probe. In the finger-like papillae the distribution patterns of actin filament varied greatly with actin localization. In the basal region fusiform bodies emitting intense fluorescence were scat- teredly distributed. In the middle zone(often occupied by dense cytoplasm) a network composed of numerous actin filaments appeared. These filaments of various diameters lay more or less paral- lelly to the cell axis,extending upwards and gradually merging into some thick dense bundles. In the apical region a few actin filaments sparsely and longitudinally distrubuted in the subcortical cytoplasm, and diffuse fluorescence often appeared in the spheroidal protrusion. Furthermore, an actin network composed of very thin filaments in the periplasm of the cell was observed;the con- stituent filaments were in helical arrangement and often branched and interconnected. Considering possible relationship between the actin configurations and the physiological activities and functions of the stigma cells, it is proposed that the active cytoplasmic streaming,the translocation of solutes towards the apical region, the active secretion of exudate from the spheroidal protrusion and main- taining of the structural integrity and stability of periplasm,all these might be considered as cer- tain physiological events being affected or regulated by the actin filament patterns described above.