title: Synergistic Activation of RD29A Via Integration of Salinity Stress and Abscisic Acid in Arabidopsis thaliana.
abstract: Plants perceive information from the surroundings and elicit appropriate molecular responses. How plants dynamically respond to combinations of external inputs is yet to be revealed, despite the detailed current knowledge of intracellular signaling pathways. We measured dynamics of Response-to-Dehydration 29A (RD29A) expression induced by single or combined NaCl and ABA treatments in Arabidopsis thaliana. RD29A expression in response to a combination of NaCl and ABA leads to unique dynamic behavior that cannot be explained by the sum of responses to individual NaCl and ABA. To explore the potential mechanisms responsible for the observed synergistic response, we developed a mathematical model of the DREB2 and AREB pathways based on existing knowledge, where NaCl and ABA act as the cognate inputs, respectively, and examined various system structures with cross-input modulation, where non-cognate input affects expression of the genes involved in adjacent signaling pathways. The results from the analysis of system structures, combined with the insights from microarray expression profiles and model-guided experiments, predicted that synergistic activation of RD29A originates from enhancement of DREB2 activity by ABA. Our analysis of RD29A expression profiles demonstrates that a simple mathematical model can be used to extract information from temporal dynamics induced by combinatorial stimuli and produce experimentally testable hypotheses.
authors: Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
authors: Sang Y
authors: SY
authors: Lee
authors: Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
authors: Neville J
authors: NJ
authors: Boon
authors: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
authors: Alex A R
authors: AA
authors: Webb
authors: Department of Bioengineering, Imperial College London, London SW7 2AZ, UK r.tanaka@imperial.ac.uk.
authors: Reiko J
authors: RJ
authors: Tanaka
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003198:Computer Simulation; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D054712:Salinity; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C520629:RD29a protein, Arabidopsis; D012965:Sodium Chloride; D000040:Abscisic Acid
keywords: Combined stress; Gene expression dynamics; Mathematical modeling; Plant abiotic stresses; Signaling cross-talk