Circadian and Light Regulated Expression of CBFs and their Upstream Signalling Genes in Barley

• Published in: International journal of molecular sciences 2017-08, Vol.18 (8), p.1828
• Main Authors: Gierczik, Krisztián, Novák, Aliz, Ahres, Mohamed, Székely, András, Soltész, Alexandra, Boldizsár, Ákos, Gulyás, Zsolt, Kalapos, Balázs, Monostori, István, Kozma-Bognár, László, Galiba, Gábor, Vágújfalvi, Attila
• Format: Article
• Language: English
• Subjects: Acclimation; Acclimatization; Barley; Calcium - metabolism; calcium signalling; CBF gene; CBF protein; Circadian Clocks - genetics; Circadian rhythm; Circadian Rhythm - genetics; Circadian rhythms; Cold; Cold acclimation; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Plant - radiation effects; Genes; Hordeum - physiology; HvCBF-phylogenetic subgroups; Light; Light emitting diodes; light quality; Lipid Metabolism - genetics; low red/far-red ratio; Phospholipids; Phospholipids - metabolism; Phylogeny; Signal processing; Signal transduction; Signal Transduction - radiation effects; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms18081828

CBF (C-repeat binding factor) transcription factors show high expression levels in response to cold; moreover, they play a key regulatory role in cold acclimation processes. Recently, however, more and more information has led to the conclusion that, apart from cold, light-including its spectra-also has a crucial role in regulating expression. Earlier, studies established that the expression patterns of some of these regulatory genes follow circadian rhythms. To understand more of this complex acclimation process, we studied the expression patterns of the signal transducing pathways, including signal perception, the circadian clock and phospholipid signalling pathways, upstream of the gene regulatory hub. To exclude the confounding effect of cold, experiments were carried out at 22 °C. Our results show that the expression of genes implicated in the phospholipid signalling pathway follow a circadian rhythm. We demonstrated that, from among the tested genes expressed in ( ) under our conditions, only the members of the HvCBF4-phylogenetic subgroup showed a circadian pattern. We found that the HvCBF4-subgroup genes were expressed late in the afternoon or early in the night. We also determined the expression changes under supplemental far-red illumination and established that the transcript accumulation had appeared four hours earlier and more intensely in several cases. Based on our results, we propose a model to illustrate the effect of the circadian clock and the quality of the light on the elements of signalling pathways upstream of the s, thus integrating the complex regulation of the early cellular responses, which finally lead to an elevated abiotic stress tolerance.