Abstract
Seeds of paper birch (Betula papyrifera Marsh.) were induced to germinate by prechilling at 3 C or by red light. The light requirement was mediated by phytochrome and the action of phytochrome during prechilling was investigated. Red irradiation (R) prior to prechilling markedly enhanced the effectiveness of the prechilling treatment in inducing subsequent germination at 18 C. Reversal of this enhancement by far-red irradiation (FR) was more effective when FR was supplied after a 1-week prechill treatment than after a 2-week treatment. The R enhancement effect exhibited a sharp drop as prechilling temperature was increased from 5 to 7 C. This decline is consistent with a membrane phase transition at about 7 C where Pfr action is diminished by a loss in sensitivity of its receptor sites. Although phytochrome action was observed during prechilling treatments, the seeds failed to germinate at prechilling temperatures. Therefore, it was concluded that while potentiation of germination by Pfr occurred during prechilling, some other reaction(s) leading to radicle protrusion requires higher temperatures. In one seed source loss of germination potential was observed with protracted storage at 3 C. This was prevented by R supplied during the prechilling treatment. Taken collectively the data suggest that action of phytochrome during prechilling is accentuated in these seeds by two factors: (a) an increase in the sensitivity (or number) of Pfr receptor sites; and (b) preservation of Pfr by deferment of thermal reversion.
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Selected References
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- Borthwick H. A., Hendricks S. B., Parker M. W., Toole E. H., Toole V. K. A Reversible Photoreaction Controlling Seed Germination. Proc Natl Acad Sci U S A. 1952 Aug;38(8):662–666. doi: 10.1073/pnas.38.8.662. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hendricks S. B., Taylorson R. B. Dependence of thermal responses of seeds on membrane transitions. Proc Natl Acad Sci U S A. 1979 Feb;76(2):778–781. doi: 10.1073/pnas.76.2.778. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hendricks S. B., Taylorson R. B. Variation in germination and amino Acid leakage of seeds with temperature related to membrane phase change. Plant Physiol. 1976 Jul;58(1):7–11. doi: 10.1104/pp.58.1.7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Poff K. L., Norris K. H. Four low-cost monochromatic sources of known equal intensities. Plant Physiol. 1967 Aug;42(8):1155–1157. doi: 10.1104/pp.42.8.1155. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roth-Bejerano N., Koller D., Negbi M. Mediation of phytochrome in the inductive action of low temperature on dark germination of lettuce seed at supra-optimal temperature. Plant Physiol. 1966 Jun;41(6):962–964. doi: 10.1104/pp.41.6.962. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scheibe J., Lang A. Lettuce Seed Germination: Evidence for a Reversible Light-Induced Increase in Growth Potential and for Phytochrome Mediation of the Low Temperature Effect. Plant Physiol. 1965 May;40(3):485–492. doi: 10.1104/pp.40.3.485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Taylorson R. B., Hendricks S. B. Action of Phytochrome During Prechilling of Amaranthus retroflexus L. Seeds. Plant Physiol. 1969 Jun;44(6):821–825. doi: 10.1104/pp.44.6.821. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vander Woude W. J., Toole V. K. Studies of the Mechanism of Enhancement of Phytochrome-dependent Lettuce Seed Germination by Prechilling. Plant Physiol. 1980 Aug;66(2):220–224. doi: 10.1104/pp.66.2.220. [DOI] [PMC free article] [PubMed] [Google Scholar]