title: Safeners recruit multiple signalling pathways for the orchestrated induction of the cellular xenobiotic detoxification machinery in Arabidopsis.
abstract: Safeners enhance herbicide tolerance in crop plants but not in target weeds, thus improving herbicide selectivity. The safeners isoxadifen-ethyl and mefenpyr-diethyl protect cereal crops from sulfonyl urea herbicides in postemergence application. The two safeners were shown here to induce the cellular xenobiotic detoxification machinery in Arabidopsis thaliana when applied to leaves in a way mimicking field application. Gene expression profiling revealed the induction of 446 genes potentially involved in the detoxification process. Transgenic Arabidopsis plants expressing a reporter gene under control of a safener-responsive maize promoter were used as a model system to study the safener signalling pathway. Reporter gene analysis in the tga2/3/5/6, sid2-2 and npr1 mutants as compared with the wild-type background showed that safener inducibility required TGA transcription factors and salicylic acid (SA) in a NON-EXPRESSOR of PR-1 (NPR1)-independent pathway converging on two as-1 promoter elements. For the majority of the safener-responsive Arabidopsis genes, a similar dependence on TGA transcription factors and/or SA was shown by gene expression profiling in wild-type plants as compared with the tga2/3/5/6 and sid2-2 mutants. Thirty-eight percent of the genes, however, were induced by safeners in a TGA/SA-independent manner. These genes are likely to be controlled by WRKY transcription factors and cognate W-boxes in their promoters.
authors: Institute of Plant Physiology and Biotechnology, University of Hohenheim, D-70599 Stuttgart, Germany.
authors: Carina
authors: C
authors: Behringer
authors: Klaus
authors: K
authors: Bartsch
authors: Andreas
authors: A
authors: Schaller
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D008658:Inactivation, Metabolic; D008957:Models, Genetic; D058977:Molecular Sequence Annotation; D011401:Promoter Regions, Genetic / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D017384:Sequence Deletion; D015398:Signal Transduction / Q000187:drug effects*; D014157:Transcription Factors / Q000378:metabolism; D015262:Xenobiotics / Q000494:pharmacology*
chemical_list: D029681:Arabidopsis Proteins; C105496:NPR1 protein, Arabidopsis; D014157:Transcription Factors; D015262:Xenobiotics; D020156:Salicylic Acid