Diversity and Characterization of Endophytic Bacteria Associated with Tidal Flat Plants and their Antagonistic Effects on Oomycetous Plant Pathogens
Diversity and Characterization of Endophytic Bacteria Associated with Tidal Flat Plants and their Antagonistic Effects on Oomycetous Plant Pathogens
复制标题
DOI：
10.5423/ppj.oa.06.2011.0123
复制
发表时间：
2012-03-01
影响因子：
2.3
通讯作者：
Chung, Young Ryun
中科院分区：
文献类型：
--
作者：
Bibi, Fehmida;Yasir, Muhammad;Chung, Young Ryun
从生长在韩国南海岛滩涂的6种植物（玫瑰、碱蓬、圆叶荆条、糙叶苔草、北沙参和翅果草）的根组织中分离到256株内生细菌，研究了滩涂植物对卵菌植物病原菌的拮抗作用。为了了解拮抗潜力，进行体外拮抗测定以表征和鉴定来自总群体的对卵菌植物病原体辣椒疫霉和终极腐霉具有拮抗性的菌株。9%的分离细菌对目标植物病原卵菌表现出体外抑制活性。通过16 S rRNA基因序列分析，对拮抗细菌的分类学和系统发育位置进行了研究。序列分析将拮抗菌株分为4大类（厚壁菌门（Firmicutes）、α-变形菌门（α-Proteobacteria）、γ 43旋转菌门（γ 43 roteobacteria）和放线菌门（Actinomycetes））和10个不同的属。进一步生产的次生代谢产物，水解酶和植物生长促进性状的推定的新物种的拮抗内生细菌进行了测定。这些新菌株不能被鉴定为已知的α-变形菌门的种，因此可能代表新的细菌分类群。与滩涂植物相关的出乎意料的高拮抗细菌多样性可能表明它们在滩涂植物中作为新型抗微生物化合物和生物防治剂的有希望的来源的重要性。
Endophytic bacterial communities of tidal flat plants antagonistic to oomycete plant pathogens were studied by the isolation of 256 root colonizing endophytic bacteria from surface-disinfected root tissues of six plants (Rosa rugosa, Suaeda maritima, Vitex rotundifolia, Carex scabrifolia, Glehnia littoralis and Elyinus mollis) growing in a tidal flat area of Namhae Island, Korea. To understand the antagonistic potential, an in vitro antagonistic assay was performed to characterize and identify strains that were antagonistic to the oomycete plant pathogens Phytophthora capsici and Pythium ultimum from the total population. Nine percent of the total number of isolated bacteria exhibited in vitro inhibitory activity against target plant pathogenic oomycetes. Taxonomic and phylogenetic placement of the antagonistic bacteria was investigated by analysis of the 16S rRNA gene sequences. The sequence analysis classified the antagonistic strains into four major classes of the domain bacteria (Firmicutes, a-Proteobacteria, y43roteobacteria and Actinomycetes) and 10 different genera. Further production of secondary metabolites, hydrolytic enzymes and plant growth promoting traits were determined for the putative new species of antagonistic endophytic bacteria. These new strains could not be identified as known species of a-Proteobacteria, and so may represent novel bacterial taxa. The unexpected high antagonistic bacterial diversity associated with the tidal flat plants may be indicative of their importance in tidal flat plants as a promising source of novel antimicrobial compounds and biocontrol agents.