title: Homologous NF-YC2 subunit from Arabidopsis and tobacco is activated by photooxidative stress and induces flowering.
abstract: The transcription factor NF-Y consists of the three subunits A, B and C, which are encoded in Arabidopsis in large gene families. The multiplicity of the genes implies that NF-Y may act in diverse combinations of each subunit for the transcriptional control. We aimed to assign a function in stress response and plant development to NF-YC subunits by analyzing the expression of NF-Y genes and exploitation of nf-y mutants. Among the subunit family, NF-YC2 showed the strongest inducibility towards oxidative stress, e.g. photodynamic, light, oxidative, heat and drought stress. A tobacco NF-YC homologous gene was found to be inducible by photooxidative stress generated by an accumulation of the tetrapyrrole metabolite, coproporphyrin. Despite the stress induction, an Arabidopsis nf-yc2 mutant and NF-YC2 overexpressors did not show phenotypical differences compared to wild-type seedlings in response to photooxidative stress. This can be explained by the compensatory potential of other members of the NF-YC family. However, NF-YC2 overexpression leads to an early flowering phenotype that is correlated with increased FLOWERING LOCUS T-transcript levels. It is proposed that NF-YC2 functions in floral induction and is a candidate gene among the NF-Y family for the transcriptional activation upon oxidative stress.
authors.affiliation: Institute of Biology/Plant Physiology, Humboldt-Universität Berlin, Philippstr.13, Building 12, 10115 Berlin, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Hackenberg
authors.affiliation: Institute of Biology/Plant Physiology, Humboldt-Universität Berlin, Philippstr.13, Building 12, 10115 Berlin, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Keetman
authors.affiliation: Institute of Biology/Plant Physiology, Humboldt-Universität Berlin, Philippstr.13, Building 12, 10115 Berlin, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Grimm
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D023081:CCAAT-Binding Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003304:Coproporphyrinogen Oxidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D003306:Coproporphyrins / Q000378:metabolism; D035264:Flowers / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009154:Mutation; D018384:Oxidative Stress; D052817:Phototrophic Processes; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D021122:Protein Subunits; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D029681:Arabidopsis Proteins; D023081:CCAAT-Binding Factor; D003306:Coproporphyrins; C418905:FT protein, Arabidopsis; D010940:Plant Proteins; D021122:Protein Subunits; D003304:Coproporphyrinogen Oxidase