title: A host-specific bacteria-to-plant signal molecule (Nod factor) enhances germination and early growth of diverse crop plants.
abstract: Lipo-chitooligosaccharides (LCOs), or Nod factors, are host-specific bacteria-to-plant signal molecules essential for the establishment of a successful N(2)-fixing legume-rhizobia symbiosis. At submicromolar concentrations Nod factors induce physiological changes in host and non-host plants. Here we show that the Nod factor Nod Bj V(C18:1,MeFuc) of Bradyrhizobium japonicum 532C enhances germination of a variety of economically important plants belonging to diverse botanical families: Zea mays, Oryza sativa (Poaceae), Beta vulgaris (Chenopodaceae), Glycine max, Phaseolus vulgaris (Fabaceae), and Gossypium hirsutum (Malvaceae), under laboratory, greenhouse and field conditions. Similar increases in germination were observed for filtrates of genistein-induced cultures of B. japonicum 532C, while non-induced B. japonicum, induced Bj 168 (a nodC mutant of B. japonicum deficient in Nod factor synthesis) or the pentamer of chitin did not invoke such responses, demonstrating the role of Nod factor in the observed effects. In addition, three out of four synthetic LCOs evaluated also promoted germination of corn, soybean and Arabidopsis thaliana seeds. LCO also enhanced the early growth of corn seedlings under greenhouse conditions. These findings suggest the possible use of LCOs for improved crop production.
authors.affiliation: Plant Science Department, Macdonald Campus, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Prithiviraj
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.forename: A
authors.initials: A
authors.lastname: Souleimanov
authors.forename: W M
authors.initials: WM
authors.lastname: Khan
authors.forename: D L
authors.initials: DL
authors.lastname: Smith
authors.forename: W M
authors.initials: WM
authors.lastname: Kahn
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D027461:Beta vulgaris / Q000187:drug effects / Q000254:growth & development; D018525:Germination / Q000187:drug effects* / Q000502:physiology; D003368:Gossypium / Q000187:drug effects / Q000254:growth & development; D008070:Lipopolysaccharides / Q000378:metabolism / Q000494:pharmacology*; D009586:Nitrogen Fixation / Q000187:drug effects / Q000502:physiology; D012275:Oryza / Q000187:drug effects / Q000254:growth & development; D063245:Plant Development; D010944:Plants / Q000382:microbiology*; D012639:Seeds / Q000187:drug effects* / Q000254:growth & development; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D013025:Glycine max / Q000187:drug effects / Q000254:growth & development; D013559:Symbiosis / Q000187:drug effects / Q000502:physiology; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development
chemical_list: D008070:Lipopolysaccharides; C091899:Nod factor V, Bradyrhizobium japonicum