Genome Analysis of Pseudomonas fluorescens PCL1751: A Rhizobacterium that Controls Root Diseases and Alleviates Salt Stress for Its Plant Host.
Genome Analysis of Pseudomonas fluorescens PCL1751: A Rhizobacterium that Controls Root Diseases and Alleviates Salt Stress for Its Plant Host.
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DOI：
10.1371/journal.pone.0140231
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Kuo CH
中科院分区：
文献类型：
--
作者：
Cho ST;Chang HH;Egamberdieva D;Kamilova F;Lugtenberg B;Kuo CH
荧光假单胞菌PCL 1751是从乌兹别克斯坦温室种植的番茄植物的根际分离的杆状革兰氏阴性细菌。它通过竞争养分和生态位（CNN）的机制控制由镰刀菌引起的几种植物根部疾病。这种机制不依赖于抗生素的生产，因此避免了耐药性发展的担忧，并且对环境安全。此外，这种细菌通过减轻其植物宿主的盐胁迫来促进植物生长。为了研究可能解释这些观察结果的遗传机制，我们确定了该细菌的完整基因组序列，检查了其基因内容，并与其他假单胞菌菌株进行了比较基因组学分析。荧光假单胞菌PCL1751的基因组由一条环状染色体组成，大小为6，143，950个碱基对（bp），未发现质粒，注释包括19个rRNA、70个tRNA和5，534个蛋白质编码基因。基因含量分析确定了大量的基因参与的趋化性和运动性，根际的殖民化，铁载体的生物合成，和植物保护剂的生产。与其他假单胞菌基因组的比较显示，它们的基因组大小和基因含量存在广泛的差异。分泌系统基因的存在和不存在是高度可变的。正如预期的那样，菌株之间的同线性保守性作为系统发育分化的函数而降低。原噬菌体的整合似乎是基因组重排的重要驱动力。全基因组基因含量分析对该植物根际促生菌的表型特征提供了一定的遗传学解释。广泛和通用的底物利用途径，以及参与竞争性根定殖的许多基因的存在下，提供了进一步的支持，这一发现，该菌株实现生物控制的病原体通过有效的竞争养分和生态位。
Pseudomonas fluorescens PCL1751 is a rod-shaped Gram-negative bacterium isolated from the rhizosphere of a greenhouse-grown tomato plant in Uzbekistan. It controls several plant root diseases caused by Fusarium fungi through the mechanism of competition for nutrients and niches (CNN). This mechanism does not rely on the production of antibiotics, so it avoids the concerns of resistance development and is environmentally safe. Additionally, this bacterium promotes plant growth by alleviating salt stress for its plant host. To investigate the genetic mechanisms that may explain these observations, we determined the complete genome sequence of this bacterium, examined its gene content, and performed comparative genomics analysis with other Pseudomonas strains. The genome of P. fluorescens PCL1751 consisted of one circular chromosome that is 6,143,950 base-pairs (bp) in size; no plasmid was found. The annotation included 19 rRNA, 70 tRNA, and 5,534 protein-coding genes. The gene content analysis identified a large number of genes involved in chemotaxis and motility, colonization of the rhizosphere, siderophore biosynthesis, and osmoprotectant production. In contrast, the pathways involved in the biosynthesis of phytohormones or antibiotics were not found. Comparison with other Pseudomonas genomes revealed extensive variations in their genome size and gene content. The presence and absence of secretion system genes were highly variable. As expected, the synteny conservation among strains decreased as a function of phylogenetic divergence. The integration of prophages appeared to be an important driver for genome rearrangements. The whole-genome gene content analysis of this plant growth-promoting rhizobacterium (PGPR) provided some genetic explanations to its phenotypic characteristics. The extensive and versatile substrate utilization pathways, together with the presence of many genes involved in competitive root colonization, provided further support for the finding that this strain achieves biological control of pathogens through effective competition for nutrients and niches.