Independent Action of ELF3 and phyB to Control Hypocotyl Elongation and Flowering Time

• Published in: Plant physiology (Bethesda) Vol. 122; no. 4; pp. 1149 - 1160
• Main Authors: Reed, Jason W., Nagpal, Punita, Bastow, Ruth M., Keely S. Solomon, Mandy J. Dowson-Day, Elumalai, Rangasamy P., Millar, Andrew J.
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01-04-2000; American Society of Plant Biologists
• Subjects: Arabidopsis; Base Sequence; Biological and medical sciences; Circadian rhythm; Circadian rhythms; DNA Primers; elf3 gene; ELF3 protein; Flowering; Fundamental and applied biological sciences. Psychology; Genetic mutation; Growth and Development; hy4 gene; Hypocotyl - physiology; Hypocotyls; Mutants; Mutation; Phenotype; Phenotypes; Photoreceptor Cells; Photoreceptors; Photosynthetic Reaction Center Complex Proteins; phyA gene; phyB gene; Physical agents; Phytochrome - genetics; Phytochrome - physiology; Phytochrome B; Plant cells; Plant growth; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - physiology; Plants; Plants, Genetically Modified - genetics; Plants, Genetically Modified - physiology; Protoplasts; Seedlings; Transcription Factors; Vegetative apparatus, growth and morphogenesis. Senescence; Growth; Genetic variant; Environmental factor; Photomorphogenesis; Arabidopsis thaliana; Morphogenesis; Regulation(control); Hypocotyl; Cruciferae; Dicotyledones; Light; Angiospermae; Phytochrome; Flowering; Spermatophyta; Experimental plant; Elongation
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.122.4.1149

Light regulates various aspects of plant growth, and the photoreceptor phytochrome B (phyB) mediates many responses to red light. In a screen for Arabidopsis mutants with phenotypes similar to those of phyB mutants, we isolated two new elf3 mutants. One has weaker morphological phenotypes than previously identified elf3 alleles, but still abolishes circadian rhythms under continuous light. Like phyB mutants, elf3 mutants have elongated hypocotyls and petioles, flower early, and have defects in the red light response. However, we found that elf3 mutations have an additive interaction with a phyB null mutation, with phyA or hy4 null mutations, or with a PHYB overexpression construct, and that an elf3 mutation does not prevent nuclear localization of phyB. These results suggest that either there is substantial redundancy in phyB and elf3 function, or the two genes regulate distinct signaling pathways.