ISSN:
1432-2048
Keywords:
cAMP
;
Circadian rhythms
;
Imidazole
;
Leaf movement
;
Rhythms (circadian)
;
Theophylline
;
Trifolium
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The period length of the leaf movement rhythm of Trifolium repens L. is lengthened by continuously offered cAMP (0.5–1.0 mol m-3) and theophylline (0.5–4 mol m-3). At the higher concentrations this effect is more pronounced and the rhythm damps out faster. Imidazole (0.5 and 1 mol m-3) has no effect on the period length; however, after 5 mol m-3 the rhythm is abolished. Offered as 4 h pulses the resulting phase response curves for cAMP and imidazole are similar and show delays of up to 4 h during the day position of the leaves. Theophylline pulses lead to delays of up to 5 h during closure and advances of up to 3 h during opening. No phase shift is brought about by 4-(3,4-dimethoxybenzyl)-2-imidazolidone. The results do not support the cAMP-model of the circadian clock which has been proposed by Cummings (J. theor. Biol. 55, 455–470; 1975). The effect of the substances tested could, however, be based upon influences on the transport of Ca2+.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00387893
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