title: Transcriptomics and functional genomics of ROS-induced cell death regulation by RADICAL-INDUCED CELL DEATH1.
abstract: Plant responses to changes in environmental conditions are mediated by a network of signaling events leading to downstream responses, including changes in gene expression and activation of cell death programs. Arabidopsis thaliana RADICAL-INDUCED CELL DEATH1 (RCD1) has been proposed to regulate plant stress responses by protein-protein interactions with transcription factors. Furthermore, the rcd1 mutant has defective control of cell death in response to apoplastic reactive oxygen species (ROS). Combining transcriptomic and functional genomics approaches we first used microarray analysis in a time series to study changes in gene expression after apoplastic ROS treatment in rcd1. To identify a core set of cell death regulated genes, RCD1-regulated genes were clustered together with other array experiments from plants undergoing cell death or treated with various pathogens, plant hormones or other chemicals. Subsequently, selected rcd1 double mutants were constructed to further define the genetic requirements for the execution of apoplastic ROS induced cell death. Through the genetic analysis we identified WRKY70 and SGT1b as cell death regulators functioning downstream of RCD1 and show that quantitative rather than qualitative differences in gene expression related to cell death appeared to better explain the outcome. Allocation of plant energy to defenses diverts resources from growth. Recently, a plant response termed stress-induced morphogenic response (SIMR) was proposed to regulate the balance between defense and growth. Using a rcd1 double mutant collection we show that SIMR is mostly independent of the classical plant defense signaling pathways and that the redox balance is involved in development of SIMR.
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland ; Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Mikael
authors.initials: M
authors.lastname: Brosché
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Blomster
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Salojärvi
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Cui
authors.affiliation: Department of Biology, University of Eastern Finland, Joensuu, Finland.
authors.forename: Nina
authors.initials: N
authors.lastname: Sipari
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Leppälä
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Airi
authors.initials: A
authors.lastname: Lamminmäki
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Gloria
authors.initials: G
authors.lastname: Tomai
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Shaman
authors.initials: S
authors.lastname: Narayanasamy
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Ramesha A
authors.initials: RA
authors.lastname: Reddy
authors.affiliation: Department of Biology, University of Eastern Finland, Joensuu, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Keinänen
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Kirk
authors.initials: K
authors.lastname: Overmyer
authors.affiliation: Division of Plant Biology, Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kangasjärvi
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D016923:Cell Death / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D023281:Genomics; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics*; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D009687:Nuclear Proteins; C492758:RCD1 protein, Arabidopsis; D017382:Reactive Oxygen Species