Phenotypical and molecular responses of Arabidopsis thaliana roots as a result of inoculation with the auxin-producing bacterium Azospirillum brasilense.
The auxin-producing bacterium Azospirillum brasilense Sp245 can promote the growth of several plant species. The model plant Arabidopsis thaliana was chosen as host plant to gain an insight into the molecular mechanisms that govern this interaction. The determination of differential gene expression in Arabidopsis roots after inoculation with either A. brasilense wild-type or an auxin biosynthesis mutant was achieved by microarray analysis. Arabidopsis thaliana inoculation with A. brasilense wild-type increases the number of lateral roots and root hairs, and elevates the internal auxin concentration in the plant. The A. thaliana root transcriptome undergoes extensive changes on A. brasilense inoculation, and the effects are more pronounced at later time points. The wild-type bacterial strain induces changes in hormone- and defense-related genes, as well as in plant cell wall-related genes. The A. brasilense mutant, however, does not elicit these transcriptional changes to the same extent. There are qualitative and quantitative differences between A. thaliana responses to the wild-type A. brasilense strain and the auxin biosynthesis mutant strain, based on both phenotypic and transcriptomic data. This illustrates the major role played by auxin in the Azospirillum-Arabidopsis interaction, and possibly also in other bacterium-plant interactions.
Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium.
Stijn
S
Spaepen
Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium.
Stijn
S
Bossuyt
Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium.|Fondazione Edmund Mach, Research and Innovation Centre, Via E. Mach, 1, 38010, San Michele all'Adige, Trento, Italy.
Kristof
K
Engelen
Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium.
Kathleen
K
Marchal
Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, 3001, Heverlee, Belgium.
Jos
J
Vanderleyden
D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology*; D015806:Azospirillum brasilense / Q000378:metabolism*; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D007210:Indoleacetic Acids / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D018517:Plant Roots / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development / Q000382:microbiology*; D015398:Signal Transduction / Q000235:genetics
D007210:Indoleacetic Acids
PGPR; auxin; beneficial bacteria; plant defense; transcriptome analysis