Pseudomonas sp. Hg3Tf, Hg5Tf and Hg7Tf genome sequencing and assembly. Pseudomonas

The Hg3Tf, Hg5Tf and Hg7Tf isolates are mercury-resistant endosymbionts of coltsfoot (Tussilago farfara) that show plant growth-promoting properties and biofilm formation. All three of them contain a mer operon on a plasmid, a 68 kb long fragment on the chromosome predicted to code resistance to cobalt, zinc, cadmium, copper, chromate, nickel, silver and arsenic (an ars operon containing arsenate reductases), as well as another ars operon without an arsenate reductase located at a different site on the chromosome. Metal resistance, plant growth promotion, and biofilm formation make the isolates potentially relevant for phytobioremediation studies of metal-contaminated sites. Knowledge of their genomes will allow more in-depth studies of the mechanisms of metal resistance and bacterial interaction with coltsfoot and other plants.

Hg3Tf、Hg5Tf与Hg7Tf分离菌株是款冬（Tussilago farfara）的抗汞内生共生菌，兼具植物生长促生特性与生物被膜形成能力。三株菌株的质粒上均携带汞抗性操纵子（mer operon）；其染色体上存在一段长度为68kb的片段，该片段经预测可编码对钴、锌、镉、铜、铬酸盐、镍、银及砷的抗性，其中包含一个编码砷酸还原酶的砷抗性操纵子（ars operon）；同时染色体的另一位置还存在另一个不编码砷酸还原酶的砷抗性操纵子。金属抗性、植物生长促生与生物被膜形成特性，使得这些分离菌株在金属污染场地的植物修复（phytobioremediation）研究中具备潜在应用价值。对其基因组的解析，将助力更深入地探究金属抗性机制以及细菌与款冬和其他植物的互作机制。