ISSN:
1365-3040
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3040.1988.tb01794.x
