PDF(Pubmed)
Abstract：
Stenotrophomonas strains, which are often described as plant growth promoting (PGP) bacteria, are ubiquitous in many environments. A total of 213 genomes of strains of Stenotrophomonas were analyzed using comparative genomics to better understand the ecological roles of these bacteria in the environment. The pan-genome of the 213 strains of Stenotrophomonas consists of 27,186 gene families, including 710 core gene families, 11,039 unique genes and 15,437 accessory genes. Nearly all strains of Stenotrophomonas harbor the genes for GH3-family cellulose degradation and GH2- and GH31-family hemicellulose hydrolase, as well as intact glycolysis and tricarboxylic acid cycle pathways. These abilities suggest that the strains of this genus can easily obtain carbon and energy from the environment. The Stenotrophomonas strains can respond to oxidative stress by synthesizing catalase, superoxide dismutase, methionine sulfoxide reductase, and disulfide isomerase, as well as managing their osmotic balance by accumulating potassium and synthesizing compatible solutes, such as betaine, trehalose, glutamate, and proline. Each Stenotrophomonas strain also contains many genes for resistance to antibiotics and heavy metals. These genes that mediate stress tolerance increase the ability of Stenotrophomonas strains to survive in extreme environments. In addition, many functional genes related to attachment and plant colonization, growth promotion and biocontrol were identified. In detail, the genes associated with flagellar assembly, motility, chemotaxis and biofilm formation enable the strains of Stenotrophomonas to effectively colonize host plants. The presence of genes for phosphate-solubilization and siderophore production and the polyamine, indole-3-acetic acid, and cytokinin biosynthetic pathways confer the ability to promote plant growth. These strains can produce antimicrobial compounds, chitinases, lipases and proteases. Each Stenotrophomonas genome contained 1-9 prophages and 17-60 genomic islands, and the genes related to antibiotic and heavy metal resistance and the biosynthesis of polyamines, indole-3-acetic acid, and cytokinin may be acquired by horizontal gene transfer. This study demonstrates that strains of Stenotrophomonas are highly adaptable for different environments and have strong potential for use as plant growth-promoting bacteria.
摘要：
窄食单胞菌属菌株，通常被描述为植物生长促进（PGP）细菌，在许多环境中无处不在。使用比较基因组学分析了总共213个寡养单胞菌菌株的基因组，以更好地了解这些细菌在环境中的生态作用。213株寡养单胞菌的全基因组由27,186个基因家族组成，包括710个核心基因家族，11,039个独特基因和15,437个辅助基因。几乎所有的寡养单胞菌菌株都含有GH3家族纤维素降解和GH2-和GH31家族半纤维素水解酶的基因，以及完整的糖酵解和三羧酸循环途径。这些能力表明，该属的菌株可以轻松地从环境中获得碳和能量。狭窄单胞菌菌株可以通过合成过氧化氢酶来响应氧化应激，超氧化物歧化酶,蛋氨酸亚砜还原酶，和二硫键异构酶，以及通过积累钾和合成相容的溶质来管理它们的渗透平衡，比如甜菜碱,海藻糖,谷氨酸,和脯氨酸。每个寡养单胞菌菌株还包含许多对抗生素和重金属具有抗性的基因。这些介导胁迫耐受性的基因增加了寡养单胞菌菌株在极端环境中存活的能力。此外,许多与依恋和植物定植有关的功能基因，确定了促进生长和生物防治。详细来说,与鞭毛组装相关的基因，运动性,趋化性和生物膜形成使得寡养单胞菌的菌株能够有效地定殖宿主植物。磷酸盐溶解和铁载体生产的基因和多胺的存在，吲哚-3-乙酸,和细胞分裂素生物合成途径赋予促进植物生长的能力。这些菌株可以产生抗菌化合物，几丁质酶,脂肪酶和蛋白酶。每个寡养单胞菌基因组包含1-9个噬菌体和17-60个基因组岛，以及与抗生素和重金属抗性以及多胺生物合成相关的基因，吲哚-3-乙酸,细胞分裂素可以通过水平基因转移获得。这项研究表明，Stenotrophomonas的菌株对不同的环境具有很强的适应性，并且具有用作植物生长促进细菌的强大潜力。
