title: The plant growth-promoting effect of the nitrogen-fixing endophyte Pseudomonas stutzeri A15.
abstract: The use of plant growth-promoting rhizobacteria as a sustainable alternative for chemical nitrogen fertilizers has been explored for many economically important crops. For one such strain isolated from rice rhizosphere and endosphere, nitrogen-fixing Pseudomonas stutzeri A15, unequivocal evidence of the plant growth-promoting effect and the potential contribution of biological nitrogen fixation (BNF) is still lacking. In this study, we investigated the effect of P. stutzeri A15 inoculation on the growth of rice seedlings in greenhouse conditions. P. stutzeri A15 induced significant growth promotion compared to uninoculated rice seedlings. Furthermore, inoculation with strain A15 performed significantly better than chemical nitrogen fertilization, clearly pointing to the potential of this bacterium as biofertilizer. To assess the contribution of BNF to the plant growth-promoting effect, rice seedlings were also inoculated with a nitrogen fixation-deficient mutant. Our results suggest that BNF (at best) only partially contributes to the stimulation of plant growth.
authors.affiliation: KU Leuven, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium.
authors.forename: Van T K
authors.identifier: http://orcid.org/0000-0003-3832-2294
authors.initials: VT
authors.lastname: Pham
authors.affiliation: KU Leuven-Campus De Nayer, Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Fortsesteenweg 30A, 2860, Sint-Katelijne-Waver, Belgium. hans.rediers@kuleuven.be.
authors.forename: Hans
authors.initials: H
authors.lastname: Rediers
authors.affiliation: KU Leuven, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium.
authors.forename: Maarten G K
authors.initials: MG
authors.lastname: Ghequire
authors.affiliation: Can Tho University-Campus II, Biotechnology R&D Institute, 3/2 Street, Xuan Khanh Ward, Nink Kieu, Can Tho, Vietnam.
authors.forename: Hiep H
authors.initials: HH
authors.lastname: Nguyen
authors.affiliation: KU Leuven, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium.
authors.forename: René
authors.initials: R
authors.lastname: De Mot
authors.affiliation: KU Leuven, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium.
authors.forename: Jos
authors.initials: J
authors.lastname: Vanderleyden
authors.affiliation: KU Leuven, Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, Box 2460, 3001, Leuven, Belgium.|Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany.
authors.forename: Stijn
authors.initials: S
authors.lastname: Spaepen
mesh_terms: D060026:Endophytes / Q000502:physiology; D009154:Mutation; D009584:Nitrogen / Q000494:pharmacology; D009586:Nitrogen Fixation / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D012275:Oryza / Q000382:microbiology*; D063245:Plant Development / Q000187:drug effects / Q000502:physiology; D018517:Plant Roots / Q000382:microbiology; D044223:Pseudomonas stutzeri / Q000502:physiology*
chemical_list: D009584:Nitrogen
keywords: Biological nitrogen fixation; Effect size Cohen’s d s; Endophytes; Nitrogenase-deficient mutant; Plant growth-promoting bacteria; Pseudomonas