Abstract
The flowering of Lemma perpusilla grown on half-strength Hutner's medium with sucrose under inductive photo-periods is inhibited in a periodic manner by daily transfers to water for short periods of time. The phase of maximal inhibition of flowering caused by water treatment is about 1 to 2 hours after the time of maximal sensitivity to light pulses. The rhythm of sensitivity to water treatments does not persist under continuous blue light. Supplementing the water with either Ca(NO3)2 or K2HPO4 partially reverses the inhibition of flowering, with the first salt being more effective. Supplementation with NH4NO3 or MgSO4 increases the inhibition. The water effect on flowering is not observed in plants grown on half-strength Hutner's medium without sucrose. The water treatments may act by removing or destroying a crucial precursor for photoperiodic induction, with the other conditions modifying permeability. The system provides a new technique for investigating the mechanism of photoperiodic induction.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- HAMNER K. C. Photoperiodism and circadian rhythms. Cold Spring Harb Symp Quant Biol. 1960;25:269–277. doi: 10.1101/sqb.1960.025.01.029. [DOI] [PubMed] [Google Scholar]
- Halaban R. The flowering response of coleus in relation to photoperiod and the circadian rhythm of leaf movement. Plant Physiol. 1968 Dec;43(12):1894–1898. doi: 10.1104/pp.43.12.1894. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hammer W. M., Enright J. T. Relationships between photoperiodism and circadian rhythms of activity in the house finch. J Exp Biol. 1967 Feb;46(1):43–61. doi: 10.1242/jeb.46.1.43. [DOI] [PubMed] [Google Scholar]
- Hillman W. S. Carbon dioxide output as an index of circadian timing in Lemna photoperiodism. Plant Physiol. 1970 Mar;45(3):273–279. doi: 10.1104/pp.45.3.273. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Menaker M., Eskin A. Circadian clock in photoperiodic time measurement: a test of the Bünning hypothesis. Science. 1967 Sep 8;157(3793):1182–1185. doi: 10.1126/science.157.3793.1182. [DOI] [PubMed] [Google Scholar]
- Posner H. B. Inhibitory Effect of Carbohydrate on Flowering in Lemna perpusilla. I. Interaction of Sucrose With Calcium and Phosphate Ions. Plant Physiol. 1969 Apr;44(4):562–566. doi: 10.1104/pp.44.4.562. [DOI] [PMC free article] [PubMed] [Google Scholar]