Tissue specific localization of root infection by fungal pathogens: Role of root border cells
Tissue specific localization of root infection by fungal pathogens: Role of root border cells
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DOI：
10.1094/mpmi.2002.15.11.1128
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发表时间：
2002-11-01
影响因子：
3.5
通讯作者：
Hawes, MC
中科院分区：
文献类型：
--
作者：
Gunawardena, U;Hawes, MC
当豌豆苗的根均匀接种赤壳菌或其他豌豆病原真菌的孢子，超过90%的发展在该地区的伸长在3天内病变。大多数根的更成熟的区域以及尖端没有明显的感染迹象。然而，显微镜观察显示，“外套”，由真菌菌丝与边缘细胞群体相互交织组成，覆盖了大多数根的尖端。在物理分离外套膜后，发现大多数根的下面尖端没有感染。地幔覆盖的根尖没有响应其边界细胞的入侵激活已知的防御基因，除非有入侵的尖端本身，所揭示的病变的存在。伴随着防御基因的激活是诱导的细胞壁降解酶的表达是一个标志，重新生产的边缘细胞。地幔的形成没有发生在响应nonpathogens。这些数据是一致的假设，即边缘细胞作为主机特定的“诱饵”，保护根分生组织抑制真菌感染的根尖。
When roots of pea seedlings were inoculated uniformly with spores of Nectria haematocca or other pea pathogenic fungi, more than 90% developed lesions in the region of elongation within 3 days. More mature regions of most roots as well as the tip showed no visible signs of infection. Yet, microscopic observation revealed that 'mantles,' comprised of fungal hyphae intermeshed with populations of border cells, covered the tips of most roots. After physical detachment of the mantle, the underlying tip of most roots was found to be free of infection. Mantle-covered root tips did not respond to invasion of their border cells by activation of known defense genes unless there was invasion of the tip itself, as revealed by the presence of a lesion. Concomitant with the activation of defense genes was the induction of a cell-wall degrading enzyme whose expression is a marker for renewed production of border cells. Mantle formation did not occur in response to nonpathogens. The data are consistent with the hypothesis that border cells serve as a host-specific 'decoy' that protects root meristems by inhibiting fungal infection of the root tip.