ISSN:
1365-3040
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
Abstract Blue-light-induced cell division in single-celled Adiantum protonemata was studied by using two or three pulses (pulse duration: 30 s) separated by various periods and by using relatively long irradiation (e.g. 30 min). The results showed: (1) that the response is saturated by a single pulse, (2) that after the application of a saturating pulse, the protonemata gradually become responsive to another pulse, showing time-dependent saturation to the second pulse, and (3) that although reciprocity holds in the pulse-induced response, it becomes invalid as the exposure duration extends in the range of minutes. These results were analysed in view of a reaction model in which a molecular component is considered to exist in two forms A and B. The response to a single pulse is considered to result from a light-dependent conversion of the component (A→B), and the restoration response measured by two pulses, from its dark reversion (B→A). The analyses yielded (1) the value of the constant which relates the fluence rate to the rate constant of the light-induced reaction, and (2) the rate constant of the dark reaction. The model was extended to formulate the responses to long irradiations as a function of the integrated concentration of B over time. The responses predicted by the formula by using the parameter values estimated from the pulse responses were able to explain the responses measured for long irradiation.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-3040.1988.tb01794.x
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