title: Exopolysaccharide biosynthesis is important for Mesorhizobium tianshanense: plant host interaction.
abstract: Mesorhizobium tianshanense is a nitrogen-fixing bacterium that can establish symbiotic associations with Glycyrrhiza uralensis in the form of root nodules. Nodule formation in rhizobia often requires various secreted carbohydrates. To investigate exopolysaccharide (EPS) production and function in M. tianshanense, we performed a genome-wide screen using transposon mutagenesis to identify genes involved in EPS production. We identified seven mutants that produced significantly lower amounts of EPS as well as a two-component sensor kinase/response regulator system that is involved in the activation of EPS synthesis. EPS mutants formed significantly less biofilm and displayed severely reduced nodulation capacity than wild type bacteria, suggesting that EPS synthesis can play important roles in the symbiosis process.
authors.affiliation: Department of Microbiology, MOA Key Lab of Microbiological Engineering of Agricultural Environment, Nanjing Agricultural University, Nanjing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Zengtao
authors.initials: Z
authors.lastname: Zhong
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.forename: Tao
authors.initials: T
authors.lastname: Cai
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D020561:Alphaproteobacteria / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D018441:Biofilms / Q000254:growth & development; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000032:analysis; D015964:Gene Expression Regulation, Bacterial; D029882:Glycyrrhiza uralensis / Q000382:microbiology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009586:Nitrogen Fixation; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D053204:Root Nodules, Plant / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial