Structure of dinitrogen fixing nodules in Erythrina poeppigiana
محفوظ في:
| المؤلفون: | , |
|---|---|
| التنسيق: | artículo original |
| الحالة: | Versión publicada |
| تاريخ النشر: | 1994 |
| الوصف: | The development and anatomy of root nodules induced in seedlings of Erythrina poeppigiana by a strain of Bradyrhizobium spp (CR 751) is described. Infection apparently occurred via injuries where lateral roots (devoid of root hairs) emerged. The first sign of infection was a group of epidermal cells (fluffy) on the secondary (emerging) root that covered the nodule primordium. Here, thin-walled cells with plastids and in active division were observed but not infection threads. Infection appears to have occurred via protoxylem which was preceded by a dissolution of the vessels' cell wall. A peribacteroid, membrane-generating organelle in infected cells is described. The adjacent noninfected cells showed electron dense depositions (phenolics 2). Developed nodules were spherical 0.5 to 2 cm in diameter. The surface was corky, with lenticels. The peridermis showed several layers of suberized dead cells. The cortex consisted of external, medium and internal layers. Vascular bundles ran in the medium cortex in a centripetal way to join the root vascular system at the base of the nodule. In these vascular bundles, baciliar bacteria were observed which were confirmed to be Bradyrhizobium sp (results of a separate study using immunocitochemistry). Bacteroids densely filled infected cells of the nodule medulla within peribacteroid membranes. Among infected cells non-infected auxiliary cells were seen loaded with starch granules. During later stages of root development few root hairs appeared on tertiary and secondary roots. Infection also occurred via root hairs, resulting in oblong nodules caused by a tumefaction of the root cortex. |
| البلد: | Portal de Revistas UCR |
| المؤسسة: | Universidad de Costa Rica |
| Repositorio: | Portal de Revistas UCR |
| اللغة: | Inglés |
| OAI Identifier: | oai:portal.ucr.ac.cr:article/28688 |
| الوصول للمادة أونلاين: | https://revistas.ucr.ac.cr/index.php/rbt/article/view/28688 |
| كلمة مفتاحية: | Poró Erythrina poeppigiana Bradyrhizobium sp root nodules nodule structure |