title: In vitro induction of lipo-chitooligosaccharide production in Bradyrhizobium japonicum cultures by root extracts from non-leguminous plants.
abstract: Bradyrhizobium japonicum can form a N2-fixing symbiosis with compatible leguminous plants. It can also act as a plant-growth promoting rhizobacterium (PGPR) for non-legume plants, possibly through production of lipo-chitooligosaccharides (LCOs), which should have the ability to induce disease resistance responses in plants. The objective of this work was to determine whether non-leguminous crop plants can induce LCO formation by B. japonicum cultures. Cultures treated with root extracts of soybean, corn, cotton or winter wheat were assayed for presence and level of LCO. Root extracts of soybean, corn and winter wheat all induced LCO production, with extracts of corn inducing the greatest amounts. Root washings of corn also induced LCO production, but less than the root extract. These results indicated that the stimulation of non-legume plant growth by B. japonicum could be through the production of LCOs, induced by materials excreted by the roots of non-legume plants.
authors.affiliation: The Province Key Laboratory of Fermentation Engineering and Bio-Pharmaceutical, Chemistry and Bio-Engineering College, Guizhou University of Technology, Guiyang, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Lian
authors.forename: Alfred
authors.initials: A
authors.lastname: Souleimanov
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zhou
authors.forename: Donald L
authors.initials: DL
authors.lastname: Smith
mesh_terms: D020369:Bradyrhizobium / Q000187:drug effects* / Q000378:metabolism; D003368:Gossypium; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D013025:Glycine max; D014908:Triticum; D003313:Zea mays
chemical_list: D008070:Lipopolysaccharides; D010936:Plant Extracts; C023023:lipid-linked oligosaccharides