Abstract
Etiolated wheat (Triticum aestivum cv Mercia) leaf protoplasts respond to brief red-light irradiation by increasing in volume over a 10-min incubation period (M.E. Bossen, H.A. Dassen, R.E. Kendrick, W.J. Vredenberg [1988] Planta 174: 94-100). When the calcium-sensitive dye Fluo-3 was incorporated into these protoplasts, red-light irradiation initiated calcium transients lasting about 2 min (P.S. Shacklock, N.D. Read, A.J. Trewavas [1992] Nature 358: 153-155). Release of calcium in the protoplasts by photolysis of incorporated 1-{2-amino-5-[1-hydroxy-1-(2-nitro-4, 5-methylenedioxyphenyl)-methyl]-phenoxy}-2-(2[prime]-amino-5[prime]-methylp henoxy)-ethane-N,N, N[prime],N[prime] -tetraccetic acid, tetrasodium salt (caged calcium) or caged inositol trisphosphate frequently induced transient increases in intracellular calcium levels, although the kinetics of these changes showed variation between experiments. Upon exposure to red light, a pronounced increase in the phosphorylation of a 70-kD and to a lesser extent a 60-kD peptide was observed, commencing within 15 s and continuing for up to 2 min. Simultaneous far-red and red irradiation attenuated the response. Upon release of incorporated caged calcium by cage photolysis, the labeling of these two peptides was greatly increased. When incorporated caged inositol trisphosphate was photolyzed, only the labeling of the 70-kD peptide was enhanced. Phosphorylation of the 70-kD peptide was also increased when extracellular calcium was elevated, but it decreased with increasing extracellular EGTA. These data thus provide direct evidence for the operation of an in vivo transduction sequence involving red light-dependent, calcium-sensitive protein phosphorylation.
Full Text
The Full Text of this article is available as a PDF (1.7 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blowers D. P., Trewavas A. J. Autophosphorylation of plasma membrane bound calcium calmodulin dependent protein kinase from pea seedlings and modification of catalytic activity by autophosphorylation. Biochem Biophys Res Commun. 1987 Mar 13;143(2):691–696. doi: 10.1016/0006-291x(87)91409-4. [DOI] [PubMed] [Google Scholar]
- Blowers D. P., Trewavas A. J. Rapid cycling of autophosphorylation of a ca-calmodulin regulated plasma membrane located protein kinase from pea. Plant Physiol. 1989 Aug;90(4):1279–1285. doi: 10.1104/pp.90.4.1279. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Datta N., Chen Y. R., Roux S. J. Phytochrome and calcium stimulation of protein phosphorylation in isolated pea nuclei. Biochem Biophys Res Commun. 1985 May 16;128(3):1403–1408. doi: 10.1016/0006-291x(85)91096-4. [DOI] [PubMed] [Google Scholar]
- Edwards G. E., Robinson S. P., Tyler N. J., Walker D. A. Photosynthesis by isolated protoplasts, protoplast extracts, and chloroplasts of wheat: influence of orthophosphate, pyrophosphate, and adenylates. Plant Physiol. 1978 Aug;62(2):313–319. doi: 10.1104/pp.62.2.313. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilroy S., Fricker M. D., Read N. D., Trewavas A. J. Role of Calcium in Signal Transduction of Commelina Guard Cells. Plant Cell. 1991 Apr;3(4):333–344. doi: 10.1105/tpc.3.4.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hale C. C., Roux S. J. Photoreversible calcium fluxes induced by phytochrome in oat coleoptile cells. Plant Physiol. 1980 Apr;65(4):658–662. doi: 10.1104/pp.65.4.658. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Li H., Dauwalder M., Roux S. J. Partial purification and characterization of a Ca(2+)-dependent protein kinase from pea nuclei. Plant Physiol. 1991;96:720–727. doi: 10.1104/pp.96.3.720. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Park M. H., Chae Q. Intracellular protein phosphorylation in oat (Avena sativa L.) protoplasts by phytochrome action. 1. Measurement of action spectra for the protein phosphorylation. Biochem Biophys Res Commun. 1989 Jul 14;162(1):9–14. doi: 10.1016/0006-291x(89)91954-2. [DOI] [PubMed] [Google Scholar]
- Roux S. J., Wayne R. O., Datta N. Role of calcium ions in phytochrome responses: an update. Physiol Plant. 1986;66:344–348. doi: 10.1111/j.1399-3054.1986.tb02430.x. [DOI] [PubMed] [Google Scholar]