Homologous NF-YC2 subunit from Arabidopsis and tobacco is activated by photooxidative stress and induces flowering

• Published in: International journal of molecular sciences Vol. 13; no. 3; pp. 3458 - 3477
• Main Authors: Hackenberg, Dieter, Keetman, Ulrich, Grimm, Bernhard
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-03-2012; Molecular Diversity Preservation International (MDPI)
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; CCAAT-Binding Factor - chemistry; CCAAT-Binding Factor - genetics; CCAAT-Binding Factor - metabolism; Cell death; Coproporphyrinogen Oxidase - antagonists & inhibitors; Coproporphyrinogen Oxidase - genetics; Coproporphyrinogen Oxidase - metabolism; Coproporphyrins - metabolism; Embryos; Endoplasmic reticulum; expression profile; flowering time; Flowers - growth & development; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; gene family; Genes; Genes, Plant; Genotype & phenotype; Mutation; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana - metabolism; Oxidative Stress; photooxidative stress; Phototrophic Processes; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified; Protein Subunits; Tobacco; transcription factor; Transcription factors; Transcriptional Activation; Berlin Germany; Germany; transcription factor; gene family; flowering time; expression profile; photooxidative stress
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms13033458

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.