Roles of microtubules and microfibrils in growth and differentiation of plants.

已知皮质微管(MTS)和壁微纤维(MFS)在调节单细胞植物的生长和分化中起着重要作用。然而，在组织复杂得多的多细胞植物中，皮层MT和壁面MFS在生长和分化调控中的作用尚不清楚。本研究旨在观察高等植物器官(如茎尖、茎和叶)中皮层MT和壁面MFS的总体排列与器官生长和分化的关系。取得的主要结果如下。1.建立了一种免疫荧光显微镜的改进方法，使研究皮质MTS在各器官中的排列成为可能。2.顶端组织中MTS和MFS的排列方式不同，与顶端圆顶状结构和鞘-体部结构的形成和维持相对应。3.燕麦胚芽鞘伸长过程中，表皮和内部组织具有相反的力学性质。MTS和MFS在表皮和内部组织中的排列不同，与这些力学性能相对应。4.叶的表皮细胞和薄壁细胞的MTS和MFS排列不同。单子叶植物和双子叶植物表皮细胞中MTS和MFS排列的悖论观点不同，与叶表面的生长模式相对应。这些结果表明，器官组织之间的细胞学差异值得重视，MTS和MFS可能普遍参与高等植物器官生长模式的调控。

It is known that cortical microtubules (MTs) and wall microfibrils (MFs) play important roles in the regulation of growth and differentiation of unicellular plants. However, in multi-cellular plants, which have much more complex organization, involvement of cortical MTs and wall MFs in the regulation of growth and differentiation is not clearly revealed.The present study aimed observation of the overall arrangement of cortical MTs and wall MFs throughout tissues in organs of higher plants, such as shoot apices, stems and leaves, in relation to growth and differentiation of organs. The main results obtained are followings. 1.An improvement of immunofluorescence microscopy which made possible to examine the arrangement of cortical MTs throughout organs was established. 2.Arrangements of MTs and MFs are different between the tissues of the shoot apex, corresponding to formation and maintenance of the dome-like shape of the apex and tunics-corpus structure. 3.In elongating coleoptiles of Avena, epidermis and the inner tissue have the opposite mechanical properties each other. The arrangements of MTs and MFs are different between the epidermis and the inner tissues, corresponding to these mechanical properties. 4.Arrangements of MTs and MFs are different between epidermis and parenchyma cells of leaves. The paradermal view of arrangements of MTs and MFs in epidermal cells are different between monocotyledonous and dicotyledonous plants, corresponding to the growth patterns of leaf surface.In conclusion, these results demonstrate that much attention should be paid to the cytological differences between tissues of organs and that MTs and MFs may be involved universally in the regulation of growth pattern of organs in higher plants.