title: Nitric oxide-fixation by non-symbiotic haemoglobin proteins in Arabidopsis thaliana under N-limited conditions.
abstract: Nitric oxide (NO) is an important signalling molecule that is involved in many different physiological processes in plants. Here, we report about a NO-fixing mechanism in Arabidopsis, which allows the fixation of atmospheric NO into nitrogen metabolism. We fumigated Arabidopsis plants cultivated in soil or as hydroponic cultures during the whole growing period with up to 3 ppmv of NO gas. Transcriptomic, proteomic and metabolomic analyses were used to identify non-symbiotic haemoglobin proteins as key components of the NO-fixing process. Overexpressing non-symbiotic haemoglobin 1 or 2 genes resulted in fourfold higher nitrate levels in these plants compared with NO-treated wild-type. Correspondingly, rosettes size and weight, vegetative shoot thickness and seed yield were 25, 40, 30, and 50% higher, respectively, than in wild-type plants. Fumigation with 250 ppbv15NO confirmed the importance of non-symbiotic haemoglobin 1 and 2 for the NO-fixation pathway, and we calculated a daily uptake for non-symbiotic haemoglobin 2 overexpressing plants of 250 mg N/kg dry weight. This mechanism is probably important under conditions with limited N supply via the soil. Moreover, the plant-based NO uptake lowers the concentration of insanitary atmospheric NOx, and in this context, NO-fixation can be beneficial to air quality.
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.
authors.forename: Gitto Thomas
authors.initials: GT
authors.lastname: Kuruthukulangarakoola
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.
authors.forename: Jiangli
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Research Unit Environmental Simulation, Helmholtz Zentrum München, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Albert
authors.affiliation: Research Unit Environmental Simulation, Helmholtz Zentrum München, Germany.
authors.forename: Barbro
authors.initials: B
authors.lastname: Winkler
authors.affiliation: Research Unit Environmental Simulation, Helmholtz Zentrum München, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Lang
authors.affiliation: Institute of Soil Ecology, Helmholtz Zentrum München, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Buegger
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Gaupels
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Heller
authors.affiliation: Research Unit Analytical Biogeochemistry, Helmholtz Zentrum München, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Michalke
authors.affiliation: Research Unit Protein Sciences, Helmholtz Zentrum München, Ingolstädter Landstrasse 1, 85764, Neuherberg/Munich, Germany.
authors.forename: Hakan
authors.initials: H
authors.lastname: Sarioglu
authors.affiliation: Research Unit Environmental Simulation, Helmholtz Zentrum München, Germany.
authors.forename: Jörg-Peter
authors.identifier: 0000-0002-9825-867X
authors.initials: JP
authors.lastname: Schnitzler
authors.affiliation: Department of Molecular Biology and Genetics, Aarhus University, Forsøgsvej 1, DK-4200, Slagelse, Denmark.
authors.forename: Kim Henrik
authors.initials: KH
authors.lastname: Hebelstrup
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.|Chair of Biochemical Plant Pathology, Technische Universität München, 85354, Freising, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Durner
authors.affiliation: Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lindermayr
mesh_terms: D000641:Ammonia / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D005651:Fumigation; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006454:Hemoglobins / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism* / Q000494:pharmacology; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000494:pharmacology*; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D020005:Propanols / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D026403:S-Nitrosothiols / Q000378:metabolism; D013559:Symbiosis
chemical_list: D029681:Arabidopsis Proteins; D006454:Hemoglobins; D009566:Nitrates; D009573:Nitrites; D020005:Propanols; D012333:RNA, Messenger; D026403:S-Nitrosothiols; C439395:1-phenylpropanol; D009569:Nitric Oxide; D000641:Ammonia; D009584:Nitrogen
keywords: Arabidopsis thaliana; nitric oxide-fixation; nitrogen; non-symbiotic haemoglobin