甘蔗茎尖细胞有丝分裂过程中微管骨架的变化

利用改进的冰冻切片法结合间接免疫荧光标记技术对甘蔗茎尖细胞有丝分裂过程中微管骨架的变化进行了研究。结果表明, 在甘蔗茎尖细胞有丝分裂过程中存在4种循序变化的典型微管列阵,即周质微管、早前期微管带、纺锤体微管及成膜体微管。同时, 还观察到在各种典型微管列阵相互转变过程中存在各种微管列阵的过渡状态。甘蔗茎尖正在伸长的幼叶部位细胞的周质微管主要为与细胞伸长轴相垂直的横向周质微管; 茎尖幼叶部位伸长缓慢细胞的微管主要为纵向及斜向排列的周质微管,在甘蔗茎尖幼叶基部初生增粗分生组织处, 横向、斜向、纵向及随机排列的周质微管列阵均有分布。在少数分裂前期的细胞中, 发现细胞具有2条早前期微管带, 其具体功能还不清楚。表明甘蔗茎尖细胞微管列阵的变化与许多双子叶植物及部分单子叶植物具有共同的变化规律, 进一步证明微管骨架的周期性变化在植物中具有普遍性。

Microtubule Cytoskeleton Change During Mitosis in the Shoot Apex of Sugarcane

The microtubule cytoskeleton was investigated by using improved cryosectioning and indirect immunofluores cence staining in the shoot apex of sugarc ane (Saccharum officinarum‘YueTang 86/368’). We observed four basic types of microtubule arrays: cortical, preprophase-band, spindle and phragmoplast microtubule arrays. Other transitional microtubule arrays were observed, which constituted the typical microtubule cycle in the dividing cells of plants. Cortical microtubule arrays were mainly oriented transversely to the cell elongation axis in cells of elongating young leaves in the shoot apex of sugarcane. Longitudinal and oblique cortical microtubules to the axis are the main arrays in the slowly elongating young leaves, and other cortical microtubule arrays, such as transverse, longitudinal, oblique and random microtubules, were observed in the primary thickening meristem in the primordium of the shoot apex in sugarcane. Unexpected were some double bands of preprophase-band microtubules in a small population of cells; their functions are still unknown. The results suggest that sugarcane microtubule arrays have the same periodic change patterns as those of many dicotyls and some monocotyls during cell division. The relation between the change pattern of microtubule arrays and development or morphogenesis in the shoot apex of sugarcane is discussed.