农杆菌附着于烟草、花叶芋的扫描电镜比较观察

SEM Comparative Observations of Agrobacterium tumefaciens Attachment to Nicotiana tabaccum and Caladium bicolor

用扫描电镜观察比较了共培养中农杆菌与烟草、花叶芋相互作用的差异.在烟草幼苗叶盘、茎的断面,观察到大量的细菌附着。它们通过菌体与细胞壁紧密接触、或通过纤维丝连接附着到烟草的伤口表面。类似的附着现象在花叶芋茎段表面也观察到.农杆菌能以与在烟草中相同的附着方式附着到花叶芋幼苗茎段伤口表面,特别是对维管束内及维管束周围的组织具有最大的亲和性,大量地附着到茎段维管束区域,但不能附着到叶盘断面的叶肉细胞上.

The attachment of Agrobacterium tumefaciens to dicotyledonous plant Nicotiana tabaccum and monocotyledonous plant Caladium bicolor was examined comparatively with scanning electron microscopy. A large number of agrobacteria were observed to attach to the cells on the surface cuts of tobacco leaf disks and young stems. Agrobacterial cells could attach to tobacco cell wall not only in both polar and lateral orientiations but also by celluose fibrils synthesized by the bacterium. A similar attachment pattern was also obsetrved in the co-cultivation of Agrobacterium tumefaciens with stem fragments of Caladium bicolor (The agrobactetrial cell attach to the cells on the surface cuts of the stem fragments in the same manner as they attach to tobacco cells.). In particular, Agrobactoria showed the greatest affinity for the cells in and around the vascular bundles in Caladium bicolor. However, they did not attach to the parenchyma cells on the surface cuts of Caladium bicolor leaf disks.