Dipartimento di Biologia Vegetale dell' Università and Centro di Studio sulla Micologia del Terreno, Viale Mattioli 25, 1-10125, Torino, Italy.
Planta. 1990 Mar;180(4):537-47. doi: 10.1007/BF02411452.
Two different types of contacts (or interfaces) exist between the plant host and the fungus during the vesicular-arbuscular mycorrhizal symbiosis, depending on whether the fungus is intercellular or intracellular. In the first case, the walls of the partners are in contact, while in the second case the fungal wall is separated from the host cytoplasm by the invaginated host plasmamembrane and by an interfacial material. In order to verify the origin of the interfacial material, affinity techniques which allow identification in situ of cell-wall components, were used. Cellobiohydrolase (CBH I) that binds to cellulose and a monoclonal antibody (JIM 5) that reacts with pectic components were tested on roots ofAllium porrum L. (leek) colonized byGlomus versiforme (Karst.) Berch. Both probes gave a labelling specific for the host cell wall, but each probe labelled over specific and distinct areas. The CBH I-colloidal gold complex heavily labelled the thick epidermal cell walls, whereas JIM 5 only labelled this area weakly. Labelling of the hypodermis was mostly on intercellular material after treatment with JIM 5 and only on the wall when CBH I was used. Suberin bands found on the radial walls were never labelled. Cortical cells were mostly labelled on the middle lamella with JIM 5 and on the wall with CBH I. Gold granules from the two probes were found in interfacial material both near the point where the fungus enters the cell and around the thin hyphae penetrating deep into the cell. The ultrastructural observations demonstrate that cellulose and pectic components have different but complementary distributions in the walls of root cells involved in the mycorrhizal symbiosis. These components show a similar distribution in the interfacial material laid down around the vesicular-arbuscular mycorrhizal fungus indicating that the interfacial material is of host origin.
在泡囊丛枝菌根共生中，植物宿主和真菌之间存在两种不同类型的接触（或界面），这取决于真菌是细胞间的还是细胞内的。在第一种情况下，伙伴的细胞壁相互接触，而在第二种情况下，真菌壁被凹陷的宿主质膜和界面物质与宿主细胞质隔开。为了验证界面物质的来源，使用了亲和技术，该技术允许原位鉴定细胞壁成分。对被Glomus versiforme (Karst.) Berch 定殖的葱属植物（韭菜）的根进行了纤维素酶（CBH I）和一种与果胶成分反应的单克隆抗体（JIM 5）的亲和实验。两种探针都对宿主细胞壁进行了特异性标记，但每种探针都标记了特定而不同的区域。CBH I-胶体金复合物强烈标记厚表皮细胞壁，而 JIM 5 仅对此区域进行弱标记。用 JIM 5 处理后，下皮的标记主要在细胞间物质上，而当使用 CBH I 时仅在细胞壁上进行。在径向壁上发现的角质带从未被标记过。皮层细胞主要在用 JIM 5 标记在中间层上，用 CBH I 标记在细胞壁上。来自两种探针的金颗粒都存在于靠近真菌进入细胞的点和穿透细胞深处的细菌丝周围的界面物质中。超微结构观察表明，纤维素和果胶成分在参与菌根共生的根细胞细胞壁中具有不同但互补的分布。这些成分在围绕泡囊丛枝菌根真菌形成的界面物质中分布相似，表明界面物质来自宿主。
