title: Proteome reference maps of the Lotus japonicus nodule and root.
abstract: Legume symbiosis with rhizobia results in the formation of a specialized organ, the root nodule, where atmospheric dinitrogen is reduced to ammonia. In Lotus japonicus (Lotus), several genes involved in nodule development or nodule function have been defined using biochemistry, genetic approaches, and high-throughput transcriptomics. We have employed proteomics to further understand nodule development. Two developmental stages representing nodules prior to nitrogen fixation (white) and mature nitrogen fixing nodules (red) were compared with roots. In addition, the proteome of a spontaneous nodule formation mutant (snf1) was determined. From nodules and roots, 780 and 790 protein spots from 2D gels were identified and approximately 45% of the corresponding unique gene accessions were common. Including a previous proteomics set from Lotus pod and seed, the common gene accessions were decreased to 7%. Interestingly, an indication of more pronounced PTMs in nodules than in roots was determined. Between the two nodule developmental stages, higher levels of pathogen-related 10 proteins, HSPs, and proteins involved in redox processes were found in white nodules, suggesting a higher stress level at this developmental stage. In contrast, protein spots corresponding to nodulins such as leghemoglobin, asparagine synthetase, sucrose synthase, and glutamine synthetase were prevalent in red nodules. The distinct biochemical state of nodules was further highlighted by the conspicuous presence of several nitrilases, ascorbate metabolic enzymes, and putative rhizobial effectors.
authors.affiliation: Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Centre for Carbohydrate Recognition and Signalling, Aarhus University, Aarhus, Denmark.
authors.forename: Svend
authors.initials: S
authors.lastname: Dam
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Dyrlund
authors.forename: Anna
authors.initials: A
authors.lastname: Ussatjuk
authors.forename: Bjarne
authors.initials: B
authors.lastname: Jochimsen
authors.forename: Kasper
authors.initials: K
authors.lastname: Nielsen
authors.forename: Nicolas
authors.initials: N
authors.lastname: Goffard
authors.forename: Miguel
authors.initials: M
authors.lastname: Ventosa
authors.forename: Andrea
authors.initials: A
authors.lastname: Lorentzen
authors.forename: Vikas
authors.initials: V
authors.lastname: Gupta
authors.forename: Stig U
authors.initials: SU
authors.lastname: Andersen
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Enghild
authors.forename: Clive W
authors.initials: CW
authors.lastname: Ronson
authors.forename: Peter
authors.initials: P
authors.lastname: Roepstorff
authors.forename: Jens
authors.initials: J
authors.lastname: Stougaard
mesh_terms: D018506:Gene Expression Regulation, Plant; D000070116:Lotus / Q000737:chemistry / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D009154:Mutation; D009586:Nitrogen Fixation; D010940:Plant Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D020543:Proteome / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D053204:Root Nodules, Plant / Q000737:chemistry / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D015398:Signal Transduction; D013559:Symbiosis
chemical_list: D010940:Plant Proteins; D020543:Proteome
keywords: Comparative analysis; Lotus japonicus; Plant proteomics; Root; Root nodule