The Calcium Rhythms of Different Cell Types Oscillate with Different Circadian Phases

• Published in: Plant physiology (Bethesda) Vol. 125; no. 2; pp. 787 - 796
• Main Authors: Nicola T. Wood, Haley, Ann, Martine Viry-Moussaïd, Johnson, Carl H., Arnold H. van der Luit, Anthony J. Trewaves
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.02.2001; American Society of Plant Biologists
• Subjects: Aequorin - genetics; Biological and medical sciences; Calcium; Calcium - physiology; Cell biochemistry; Cell Biology and Signal Transduction; Cell physiology; Circadian rhythm; Circadian Rhythm - physiology; Circadian rhythms; Cotyledons; Cytosol - metabolism; Epidermal cells; Fundamental and applied biological sciences. Psychology; Guard cells; Luminescence; Molecular and cellular biology; Nicotiana - genetics; Nicotiana - physiology; Oscillators; Plant physiology and development; Plants; Plants, Genetically Modified - physiology; Seedlings; Signal transduction; Transgenic plants; Cell function; Calcium; Enzyme; Cell nucleus; Biological rhythm; Concentration; Circadian rhythm; Cytosol; Signal transduction; Nicotiana plumbaginifolia; Regulation(control); Dicotyledones; Angiospermae; Spermatophyta; Transgenic plant; Oxidoreductases; Solanaceae; Experimental plant; Localization; Renilla-luciferin 2-monooxygenase; Comparative study
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.125.2.787

Transgenic tobacco (Nicotiana plumbaginifolia) seedlings containing the Ca2+-sensitive luminescent protein aequorin have been shown to exhibit circadian variations in cytosolic calcium. Concomitant measurements of cytosolic and nuclear calcium show that circadian variations in the cytoplasm are not expressed in the nucleus. To investigate whether all cells of transgenic seedlings contribute equally to circadian variations in cytosolic calcium, different promoters eliciting different expression patterns have been placed upstream of aequorin and used for transformation. The circadian peak occurred at different times in the three transgenic lines constructed. Luminescence imaging of these transgenic lines indicated that aequorin was differentially accumulated among the main tissues and cells of the seedlings and overcoat technology with applied epidermal strips indicated that the surface cell layers contribute the vast majority of luminescent light. We conclude that the Ca2+ rhythmicities of cells and tissues oscillate with distinct differences in phase, that this might represent different underlying cellular control mechanisms and that these observations have significant implications for our understanding and study of Ca2+ mediated signal transduction in plant cells.