Light signalling mediated by phytochrome plays an important role in cold-induced gene expression through the C-repeat/dehydration responsive element (C/DRE) in Arabidopsis thaliana.

Abstract

Low temperature induces a number of genes that encode the proteins promoting tolerance to freezing, mediated by ABA-dependent and ABA-independent pathways in plants. The cis-acting element called C/DRE is known to respond to low temperature independently of ABA action. To investigate the signalling and network of ABA-independent pathways, the transgenic Arabidopsis plants were generated containing several copies of the C/DRE derived from cor15a gene with a minimal promoter fused to a GUS reporter gene. The transgenic plants containing four copies of the C/DRE (4C/DRE-GUS) showed responsiveness to cold and drought treatments and were used for characterization of cold signalling and cross-talk. Cold-induced GUS expression was inhibited by okadaic acid at 1 nM, indicating that protein phosphatase 2A might act as a positive regulator. Light was shown to activate cold- and drought-induced GUS expression. Photo-reversibility of the GUS mRNA by red and far-red light with concomitant cold treatment suggests a role of phytochrome as a photoreceptor in mediating light signalling to activate the cold-induced gene expression through the C/DRE. Furthermore, GUS expression analysis in phyA or phyB or phyAphyB mutant backgrounds showed that phytochrome B is a primary photoreceptor responsible for the activation of cold-stress signalling in response to light. Light enhanced the induction kinetics of CBF1, 2, and 3 encoding the cognate transcription factors, and cor15a, in a consecutive manner compared to the dark condition in the cold, suggesting that the connection point between cold and light signalling mediated by phytochrome is at a higher step than the expression of CBF genes.

• Authors: Hyoun-Joung Kim, Yun-Kyoung Kim, Jin-Young Park, Jungmook Kim
• Journal: The Plant journal : for cell and molecular biology (Plant J) Vol. 29 Issue 6 Pg. 693-704 (Mar 2002) ISSN: 0960-7412 [Print] England
• PMID: 12148528 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Arabidopsis Proteins
• CBF1 protein, Arabidopsis
• COR15 protein, Arabidopsis
• DNA-Binding Proteins
• DREB1A protein, Arabidopsis
• PHYB protein, Arabidopsis
• Trans-Activators
• Transcription Factors
• Phytochrome
• Phytochrome B
• Okadaic Acid
• Sodium Chloride
• Abscisic Acid
• Diuron
• Phosphoprotein Phosphatases
• Protein Phosphatase 2
• Staurosporine

Topics

• Abscisic Acid (pharmacology)
• Acclimatization (drug effects, radiation effects)
• Arabidopsis (genetics, physiology)
• Arabidopsis Proteins (genetics)
• Cold Temperature
• DNA-Binding Proteins (genetics)
• Darkness
• Disasters
• Diuron (pharmacology)
• Gene Expression Regulation (drug effects, radiation effects)
• Light
• Mutation
• Okadaic Acid (pharmacology)
• Phosphoprotein Phosphatases (metabolism)
• Photoreceptor Cells
• Phytochrome (drug effects, metabolism, radiation effects)
• Phytochrome B
• Plants, Genetically Modified
• Protein Phosphatase 2
• Signal Transduction (drug effects, physiology, radiation effects)
• Sodium Chloride (pharmacology)
• Staurosporine (pharmacology)
• Trans-Activators (genetics)
• Transcription Factors (genetics)