Phytophthora parasitica biofilm formation:: installation and organization of microcolonies on the surface of a host plant
Phytophthora parasitica biofilm formation:: installation and organization of microcolonies on the surface of a host plant
复制标题
DOI：
10.1111/j.1462-2920.2008.01619.x
复制
发表时间：
2008-08-01
影响因子：
5.1
通讯作者：
Engler, Gilbert
中科院分区：
文献类型：
--
作者：
Galiana, Eric;Fourre, Sandra;Engler, Gilbert
卵菌寄生疫霉的游动孢子在其宿主烟草的受伤叶片表面上建立微生物球状小菌落和生物膜。小菌落的形成涉及一些游动孢子从伤口部位向引诱剂移动，随后它们被不可逆地吸附并形成一簇细胞。这些细胞通过建立外部趋化梯度驱动第二波游动孢子（数百个细胞）的迁移，导致大量游动孢子包囊化和包囊定向萌发。在这个阶段仍然游动的游动孢子通过打开通道在新生的生物膜内循环。同时，细胞群分泌各种物质来制造细胞外粘液。包埋在细胞外基质中，生物膜细胞被组织成结构化的群落作为凝聚体。颗粒状表面由位于小菌落外部的单个包囊组成。这些孢囊中的菌丝向下扎向创始细胞形成的致密核心。这份报告是第一个显示的安装和组织的生物膜形成的真核细胞在植物表面。寄生疟原虫小菌落构成了嵌入和循环细胞的异质微环境。它们可能影响植物-病原体相互作用，作为病原微生物的储存库，作为保护生态位免受宿主防御或作为感染种群的结构。
Zoospores of the oomycete Phytophthora parasitica establish microbial spheroid microcolonies and biofilms on the surface of wounded leaves of their host, Nicotiana tabacum. The formation of microcolonies involves the movement of some zoospores towards attractants from wound sites, followed by their irreversible adsorption and the formation of a cluster of cells. These cells drive the migration of a second wave of zoospores (several hundreds cells) by setting up an external chemotactic gradient leading to massive zoospore encystment and cyst-orientated germination. Zoospores that are still swimming at this stage circulate within the nascent biofilm by opening channels. Concomitantly, the cell population secretes various substances to elaborate an extracellular mucilage. Embedded within the extracellular matrix, biofilm cells are organized into a structured community as coacervates. The granular surface is composed of individual cysts, located on the outside of the microcolony. Hyphae from these cysts plunge downwards towards the dense core formed by the founder cells. This report is the first to show the installation and organization of a biofilm formed by eukaryotic cells on plant surfaces. The P. parasitica microcolonies constitute heterogeneous microenvironments for the embedded and circulating cells. They may affect plant-pathogen interactions by serving as reservoirs for pathogenic microorganisms, as protecting niche against host defences or as structures for infecting populations.