Fester T, Hause G
Leibniz-Institut für Pflanzenbiochemie, Weinberg 3, 06120 Halle (Saale), Germany.
Mycorrhiza. 2005 Jul;15(5):373-9. doi: 10.1007/s00572-005-0363-4. Epub 2005 May 4.
We investigated the accumulation of reactive oxygen species (ROS) in arbuscular mycorrhizal (AM) roots from Medicago truncatula, Zea mays and Nicotiana tabacum using three independent staining techniques. Colonized root cortical cells and the symbiotic fungal partner were observed to be involved in the production of ROS. Extraradical hyphae and spores from Glomus intraradices accumulated small levels of ROS within their cell wall and produced ROS within the cytoplasm in response to stress. Within AM roots, we observed a certain correlation of arbuscular senescence and H2O2 accumulation after staining by diaminobenzidine (DAB) and a more general accumulation of ROS close to fungal structures when using dihydrorhodamine 123 (DHR 123) for staining. According to electron microscopical analysis of AM roots from Z. mays after staining by CeCl3, intracellular accumulation of H2O2 was observed in the plant cytoplasm close to intact and collapsing fungal structures, whereas intercellular H2O2 was located on the surface of fungal hyphae. These characteristics of ROS accumulation in AM roots suggest similarities to ROS accumulation during the senescence of legume root nodules.
我们使用三种独立的染色技术，研究了来自蒺藜苜蓿、玉米和烟草的丛枝菌根（AM）根中活性氧（ROS）的积累情况。观察到定殖的根皮层细胞和共生真菌伙伴参与了ROS的产生。根内球囊霉的根外菌丝和孢子在其细胞壁内积累少量ROS，并在受到胁迫时在细胞质内产生活性氧。在AM根中，用二氨基联苯胺（DAB）染色后，我们观察到丛枝衰老与H2O2积累之间存在一定的相关性，而使用二氢罗丹明123（DHR 123）染色时，ROS在真菌结构附近有更普遍的积累。根据用CeCl3染色后的玉米AM根的电子显微镜分析，在靠近完整和正在解体的真菌结构的植物细胞质中观察到H2O2的细胞内积累，而细胞间的H2O2位于真菌菌丝的表面。AM根中ROS积累的这些特征表明，其与豆科植物根瘤衰老过程中的ROS积累具有相似性。
