Abstract
Leaf senescence and abscission have been studied in the semi-parasitic plant mistletoe (Viscum album). Leaf senescence and abscission occur in the summer, when the metabolic activity of the host has reached its maximum. In contrast with their hosts, mistletoes selectively degrade only one major leaf protein during leaf senescence, the sulfur-rich viscotoxin, whereas most of the remaining leaf proteins are lost during abscission. The changes in viscotoxin content are paralleled by changes in the concentration of the corresponding mRNA. Shortly before the onset of leaf senescence, the mRNA for viscotoxin has disappeared from the leaves. The anticyclic timing of leaf senescence and the degradation of only one major leaf protein seems to reflect an adaptation of the parasite to its habitat.
Full Text
The Full Text of this article is available as a PDF (1.6 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allen M. M., Smith A. J. Nitrogen chlorosis in blue-green algae. Arch Mikrobiol. 1969;69(2):114–120. doi: 10.1007/BF00409755. [DOI] [PubMed] [Google Scholar]
- Bohlmann H., Clausen S., Behnke S., Giese H., Hiller C., Reimann-Philipp U., Schrader G., Barkholt V., Apel K. Leaf-specific thionins of barley-a novel class of cell wall proteins toxic to plant-pathogenic fungi and possibly involved in the defence mechanism of plants. EMBO J. 1988 Jun;7(6):1559–1565. doi: 10.1002/j.1460-2075.1988.tb02980.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chirgwin J. M., Przybyla A. E., MacDonald R. J., Rutter W. J. Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. Biochemistry. 1979 Nov 27;18(24):5294–5299. doi: 10.1021/bi00591a005. [DOI] [PubMed] [Google Scholar]
- Ferreira R. M., Teixeira A. R. Sulfur starvation in Lemna leads to degradation of ribulose-bisphosphate carboxylase without plant death. J Biol Chem. 1992 Apr 15;267(11):7253–7257. [PubMed] [Google Scholar]
- Forde B. G., Kreis M., Bahramian M. B., Matthews J. A., Miflin B. J., Thompson R. D., Bartels D., Flavell R. B. Molecular cloning and analysis of cDNA sequences derived from poly A+ RNA from barley endosperm: identification of B hordein related clones. Nucleic Acids Res. 1981 Dec 21;9(24):6689–6707. doi: 10.1093/nar/9.24.6689. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Franz H. Inhaltsstoffe der Mistel (Viscum album L.) als potentielle Arzneimittel. Pharmazie. 1985 Feb;40(2):97–104. [PubMed] [Google Scholar]
- Melzer S., Majewski D. M., Apel K. Early Changes in Gene Expression during the Transition from Vegetative to Generative Growth in the Long-Day Plant Sinapis alba. Plant Cell. 1990 Oct;2(10):953–961. doi: 10.1105/tpc.2.10.953. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SAMUELSSON G. Phytochemical and pharmacological studies on Viscum album L. V. Further improvements in the isolation methods for viscotoxin. Studies on viscotoxin from Viscum album growing on Tilia cordata Mill. Sven Farm Tidskr. 1961 Jul 10;65:481–494. [PubMed] [Google Scholar]
- Schrader G., Apel K. Isolation and characterization of cDNAs encoding viscotoxins of mistletoe (Viscum album). Eur J Biochem. 1991 Jun 15;198(3):549–553. doi: 10.1111/j.1432-1033.1991.tb16049.x. [DOI] [PubMed] [Google Scholar]
- Spurr A. R. A low-viscosity epoxy resin embedding medium for electron microscopy. J Ultrastruct Res. 1969 Jan;26(1):31–43. doi: 10.1016/s0022-5320(69)90033-1. [DOI] [PubMed] [Google Scholar]