This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/11/3474    most recent tpc.106.046011v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Plant Cell Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Xu, X. Articles by Webb, A. A.R. Search for Related Content PubMed PubMed Citation Articles by Xu, X. Articles by Webb, A. A.R. Agricola Articles by Xu, X. Articles by Webb, A. A.R.

Distinct Light and Clock Modulation of Cytosolic Free Ca²⁺ Oscillations and Rhythmic CHLOROPHYLL A/B BINDING PROTEIN2 Promoter Activity in Arabidopsis^[W]

^a Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235
^b Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
^c Department of Plant Sciences, Montana State University, Bozeman, Montana 59717

⁴ Address correspondence to alex.webb{at}plantsci.cam.ac.uk.

Plants have circadian oscillations in the concentration of cytosolic free calcium ([Ca²⁺]_cyt). To dissect the circadian Ca²⁺-signaling network, we monitored circadian [Ca²⁺]_cyt oscillations under various light/dark conditions (including different spectra) in Arabidopsis thaliana wild type and photoreceptor and circadian clock mutants. Both red and blue light regulate circadian oscillations of [Ca²⁺]_cyt. Red light signaling is mediated by PHYTOCHROME B (PHYB). Blue light signaling occurs through the redundant action of CRYPTOCHROME1 (CRY1) and CRY2. Blue light also increases the basal level of [Ca²⁺]_cyt, and this response requires PHYB, CRY1, and CRY2. Light input into the oscillator controlling [Ca²⁺]_cyt rhythms is gated by EARLY FLOWERING3. Signals generated in the dark also regulate the circadian behavior of [Ca²⁺]_cyt. Oscillations of [Ca²⁺]_cyt and CHLOROPHYLL A/B BINDING PROTEIN2 (CAB2) promoter activity are dependent on the rhythmic expression of LATE ELONGATED HYPOCOTYL and CIRCADIAN CLOCK-ASSOCIATED1, but [Ca²⁺]_cyt and CAB2 promoter activity are uncoupled in the timing of cab1 (toc1-1) mutant but not in toc1-2. We suggest that the circadian oscillations of [Ca²⁺]_cyt and CAB2 promoter activity are regulated by distinct oscillators with similar components that are used in a different manner and that these oscillators may be located in different cell types in Arabidopsis.

Related articles in Plant Cell:

Circadian Regulation of Cytosolic Ca²⁺

Nancy A. Eckardt
Plant Cell 2007 19: 3317. [Full Text]  

This article has been cited by other articles:

				A. N. Dodd, M. J. Gardner, C. T. Hotta, K. E. Hubbard, N. Dalchau, F. C. Robertson, J. Love, D. Sanders, and A. A. R. Webb Response to Comment on "The Arabidopsis Circadian Clock Incorporates a cADPR-Based Feedback Loop" Science, October 9, 2009; 326(5950): 230 - 230. [Abstract] [Full Text] [PDF]

				X. Chen, W.-H. Lin, Y. Wang, S. Luan, and H.-W. Xue An Inositol Polyphosphate 5-Phosphatase Functions in PHOTOTROPIN1 Signaling in Arabidopis by Altering Cytosolic Ca2+ PLANT CELL, February 1, 2008; 20(2): 353 - 366. [Abstract] [Full Text] [PDF]