Plant and Cell Physiology Advance Access originally published online on May 26, 2005
Plant and Cell Physiology 2005 46(8):1226-1236; doi:10.1093/pcp/pci131
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
UV-A Induces Two Calcium Waves in Physcomitrella patens
1 Natural Science Department, Baruch College, City University of New York, 17 Lexington Avenue, New York, NY 10010, USA
2 Department of Biology, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji-shi, Tokyo, 192-03 Japan
3 Department of Cell Biology, Scripps Research Institute, 10550 North Terry Pines Road, La Jolla, CA 92037, USA
4 Gene Research Center, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509 Japan
5 Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
* Corresponding author: E-mail, edward_tucker{at}baruch.cuny.edu; Fax, +1-212-802-3082.
Our understanding of the role of Ca2+ in blue/UV-A photoreceptor signaling in a single cell is limited. Insight into calcium signaling has now been attained in Physcomitrella patens and its cryptochrome and phototropin knock-outs. Physcomitrella patens caulonemal filaments grow in the dark by apical extension and their apical cells are highly polarized. Fura-2-dextran ratio images of the apical cell from wild type (WT), Ppcry1a/1b and PpphotA2/B1/B2 were obtained immediately following UV-A exposure (30 µW cm–2 at 340 nm for 1,000 ms plus 30 µW cm–2 at 380 nm for 1,000 ms) [abbreviated as 1,000 ms (340/380 nm)] and demonstrated two intracellular waves: a Ca2+ wave from the growing apical tip through the apical cap, and a wave from the junction of the neighboring cell through the vacuolar, nuclear and plastid regions. In WT, the UV-A-induced tip wave increase had a magnitude of 454.0 ± 40 nM, traveled at a rate of 3.4 ± 0.7 µm s–1 and was complete within 26.6 ± 2.3 s, while the basal vacuolar wave had a magnitude of 596.8 ± 110 nM, a rate of 8.4 ± 0.8 µm s–1 and duration of 25.3 ± 4.9 s. Subsequent Ca2+ spikes of similar magnitude followed these waves. The amplitude of the Ca2+ waves in the apical cap and basal vacuolar regions of Ppcry1a/1b were higher than those in the WT, while the duration of those in PpphotA2/B1/B2 was longer. Subsequent Ca2+ spikes occurred in WT and Ppcry1a/1b but not in PpphotA2/B1/B2. When Mn2+ was added to the culture medium, the [Ca2+]cyt increase was delayed, did not move as a wave and lasted longer. The results indicate that plants respond to blue light and UV-A radiation by generating a wave of changes in the [Ca2+]cyt. The characteristics of these Ca2+ waves were dependent upon cryptochrome and phototropin. Blue/UV-A signaling in P. patens appears to differ from that in Arabidopsis.
(Received December 13, 2004; Accepted May 17, 2005)
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  E. Qudeimat, A. M. C. Faltusz, G. Wheeler, D. Lang, C. Brownlee, R. Reski, and W. Frank A PIIB-type Ca2+-ATPase is essential for stress adaptation in Physcomitrella patens PNAS, December 9, 2008; 105(49): 19555 - 19560. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. F Jaffe Calcium waves Phil Trans R Soc B, April 12, 2008; 363(1495): 1311 - 1317. [Abstract] [Full Text] [PDF]
|
|