title: Inactivation of the nodH gene in Sinorhizobium sp. BR816 enhances symbiosis with Phaseolus vulgaris L.
abstract: Sulfate modification on Rhizobium Nod factor signaling molecules is not a prerequisite for successful symbiosis with the common bean (Phaseolus vulgaris L.). However, many bean-nodulating rhizobia, including the broad host strain Sinorhizobium sp. BR816, produce sulfated Nod factors. Here, we show that the nodH gene, encoding a sulfotransferase, is responsible for the transfer of sulfate to the Nod factor backbone in Sinorhizobium sp. BR816, as was shown for other rhizobia. Interestingly, inactivation of nodH enables inoculated bean plants to fix significantly more nitrogen under different experimental setups. Our studies show that nodH in the wild-type strain is still expressed during the later stages of symbiosis. This is the first report on enhanced nitrogen fixation by blocking Nod factor sulfation.
authors.affiliation: Centre of Microbial and Plant Genetics, Kasteelpark Arenberg, Heverlee, Belgium.
authors.forename: Roseline
authors.initials: R
authors.lastname: Remans
authors.forename: Carla
authors.initials: C
authors.lastname: Snoeck
authors.forename: Christel
authors.initials: C
authors.lastname: Verreth
authors.forename: Anja
authors.initials: A
authors.lastname: Croonenborghs
authors.forename: Ellen
authors.initials: E
authors.lastname: Luyten
authors.forename: Maxime
authors.initials: M
authors.lastname: Ndayizeye
authors.forename: Esperanza
authors.initials: E
authors.lastname: Martínez-Romero
authors.forename: Jan
authors.initials: J
authors.lastname: Michiels
authors.forename: Jos
authors.initials: J
authors.lastname: Vanderleyden
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D009586:Nitrogen Fixation / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D027805:Phaseolus / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D053204:Root Nodules, Plant / Q000235:genetics / Q000382:microbiology / Q000648:ultrastructure; D020579:Sinorhizobium / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism; D013559:Symbiosis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D010088:Oxidoreductases; C029130:nitrogenase reductase; C092976:NodH protein, Sinorhizobium meliloti; D015238:Sulfotransferases