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Phenotypical and molecular responses of A rabidopsis thaliana roots as a result of inoculation with the auxin‐producing bacterium A zospirillum brasilense
Author(s) -
Spaepen Stijn,
Bossuyt Stijn,
Engelen Kristof,
Marchal Kathleen,
Vanderleyden Jos
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12590
Subject(s) - auxin , azospirillum brasilense , arabidopsis thaliana , biology , mutant , transcriptome , plant hormone , root hair , arabidopsis , wild type , gene , microbiology and biotechnology , botany , bacteria , genetics , gene expression , nitrogen fixation
Summary The auxin‐producing bacterium A zospirillum brasilense S p245 can promote the growth of several plant species. The model plant A rabidopsis 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 A rabidopsis roots after inoculation with either A . brasilense wild‐type or an auxin biosynthesis mutant was achieved by microarray analysis. A rabidopsis 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 A zospirillum–Arabidopsis interaction, and possibly also in other bacterium–plant interactions.