Genome-wide interacting effects of sucrose and herbicide-mediated stress in Arabidopsis thaliana: novel insights into atrazine toxicity and sucrose-induced tolerance
1 Centre National de la Recherche Scientifique, Université de Rennes 1, UMR 6553 ECOBIO, Campus de Beaulieu, bâtiment 14A, F-35042 Rennes Cedex, France
2 UMR INRA 1165-CNRS 8114-UEVE, Unité de Recherche en Génomique Végétale (URGV), 2, rue Gaston Crémieux, CP5708, F-91057 Evry Cedex, France
3 UMR AgroParisTech-INRA, Mathématique et Informatique Appliquées 518, F-75231 Paris Cedex 05, France
BMC Genomics 2007, 8:450 doi:10.1186/1471-2164-8-450Published: 5 December 2007
Soluble sugars, which play a central role in plant structure and metabolism, are also involved in the responses to a number of stresses, and act as metabolite signalling molecules that activate specific or hormone-crosstalk transduction pathways. The different roles of exogenous sucrose in the tolerance of Arabidopsis thaliana plantlets to the herbicide atrazine and oxidative stress were studied by a transcriptomic approach using CATMA arrays.
Parallel situations of xenobiotic stress and sucrose-induced tolerance in the presence of atrazine, of sucrose, and of sucrose plus atrazine were compared. These approaches revealed that atrazine affected gene expression and therefore seedling physiology at a much larger scale than previously described, with potential impairment of protein translation and of reactive-oxygen-species (ROS) defence mechanisms. Correlatively, sucrose-induced protection against atrazine injury was associated with important modifications of gene expression related to ROS defence mechanisms and repair mechanisms. These protection-related changes of gene expression did not result only from the effects of sucrose itself, but from combined effects of sucrose and atrazine, thus strongly suggesting important interactions of sucrose and xenobiotic signalling or of sucrose and ROS signalling.
These interactions resulted in characteristic differential expression of gene families such as ascorbate peroxidases, glutathione-S-transferases and cytochrome P450s, and in the early induction of an original set of transcription factors. These genes used as molecular markers will eventually be of great importance in the context of xenobiotic tolerance and phytoremediation.