Ultrastructural and cell wall modifications during infection of Eucalyptus viminalis roots by a pathogenic Fusarium oxysporum strain
Ultrastructural and cell wall modifications during infection of Eucalyptus viminalis roots by a pathogenic Fusarium oxysporum strain
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DOI：
10.1007/s10327-004-0107-x
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发表时间：
2004-06-01
影响因子：
1.2
通讯作者：
Gianinazzi-Pearson, Vivienne
中科院分区：
文献类型：
--
作者：
Salerno, Maria-Isabel;Gianinazzi, Silvio;Gianinazzi-Pearson, Vivienne
镰刀菌是一种土壤传播的真菌病原体，在攻击农作物时会产生各种病害症状。在超微结构水平上描述了病原菌FOEUL在桉树幼苗根部定植的方式，以及病原菌相互作用过程中细胞壁果胶的变化。在体外模拟系统中，将尖孢镰刀菌接种于青枯草的根系。尖孢镰刀菌的菌丝通过纤维状物质附着在外表皮细胞壁上，穿透后扩散到内部组织。它们在根皮层中发育为细胞间和细胞内，并侵入维管组织。在定植的细胞中诱导出乳突，寄主质膜破裂，造成寄主组织和细胞的迅速破坏。用两株单抗Jim 5和Jim 7研究了尖孢镰刀菌根定殖后未酯化果胶和甲酯化果胶的分布和存在的变化。对照根中的非酯化果胶主要分布在皮层的表皮细胞壁和中层，而甲酯化果胶在皮层和韧皮部的初级细胞壁中积累较多。免疫检测到的非酯化和甲酯化果胶的减少与病原真菌根部定植后植物组织的广泛降解有关。
Fusarium species are soil-borne fungal pathogens that produce a variety of disease symptoms when attacking crop plants. The mode of root colonization of Eucalyptus viminalis seedlings by a pathogenic F. oxyporum strain (Foeul) at the ultrastructural level and changes in cell wall pectin during host pathogen interactions are described. Root systems of E. viminalis plants were inoculated with F. oxysporum in an in vitro model system. Hyphae of F. oxysporum adhered to the outer epidermal cell walls through fibrillar material, and after penetration they spread into the internal tissues. They developed intercellularly and intracellularly in the root cortex and invaded vascular tissues. Papillae were induced, and the host plasma membrane ruptured in colonized cells, causing rapid host tissue and cell damage. Changes in distribution and occurrence of nonesterified and methyl-esterified pectins were evaluated after root colonization by F. oxysporum using two monoclonal antibodies, JIM 5 and JIM 7, respectively. Nonesterified pectin in control roots was mainly localized in the epidermal cell walls and middle lamellae in parenchymal cortex, whereas methyl-esterified pectin accumulated more in primary cell walls of the cortex and phloem. Decreases in immunodetected nonesterified and methyl-esterified pectins were associated with extensive plant tissue degradation after root colonization by the pathogenic fungus.