Changes of Microtubular Organization During the Embryo Sac Development in Rice

Abstract

Changes in the patterns of microtubular distributions and organization in various stages of development of the embryo sac in rice ( Oryza sativa L. ) were different. In the megasporocyte, most microtubules were radially distributed but some were longitudinally oriented. Similar distributional patterns were seen in the dyad cells and the functional megaspore. Microtubules in the uni-nucleate embryo sac were mostly randomly distributed, although some radiated type was also present. The pattern of distribution of the microtubules in the two and four-nucleate embryo sac was quite similar and the microtubules were mainly of the pe.rinuclear type. Microtubules in the cells of the eight-nucleate embryo sac were more complex. In the egg cell, the microtubules were mostly randomly distributed whereas in the synergids they were pred6minantly in longitudinal alignment. Those in the central cell were transversely aligned. The antipodal mass had very few microtubules and few longitudinally aligned ones were present in the cytoplasm.

對水稻(Oryza sativa L.)胚囊發育過程中微管變化的研究表明，微管在胚囊發育的不同階段變化 多樣。在大孢子母細胞階段微管分佈主要呈輻射狀，部分縱向排列。二分體和功能大孢子具類似的微管分佈，而在單核胚囊微管主要是隨機分佈，部分呈輻射狀。兩核和四核胚囊的微管組成和分佈非常相似，主要分佈於細胞核周圍。而八核胚囊的微管分佈較為複雜，胚囊中的細胞微管分佈各異，在卵細胞中呈隨機分佈，在助細胞中大多數呈縱向分佈，而在中央細胞中呈橫向分佈，微管在反足細胞中非常分散，細胞質中有少量縱向排列的微管。