Premium
Relationships between Photo‐induced and Gravity‐induced Electrical Potentials in Zea Mays
Author(s) -
Johnsson Anders
Publication year - 1967
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1967.tb07197.x
Subject(s) - stimulation , logarithm , coleoptile , stimulus (psychology) , physics , latency (audio) , biophysics , mechanics , chemistry , mathematics , mathematical analysis , neuroscience , biology , telecommunications , biochemistry , psychology , computer science , psychotherapist
A comparison is made between gravity‐induced and light‐induced transversal electrical potentials in excised coleoptiles of Zea Mays . The potentials are measured with a vibrating condensor method, thus the plants are not touched at the measuring point. It is found that all experimental evidence supports the assumption that the reaction chains leading to the potentials are identical in the two cases, apart of course from the perception stages. This theory is based on the following points which have been experimentally verified:1 The stimulus‐response functions are quite similar. In both cases the voltage is a logarithmic function of the stimulation time (at least for shorter stimulation times). When continuous stimulation is used, the stimulation time must exceed a threshold value to cause a transversal potential. 2 Some inhibitors (DNP and NaN 3 ) diminish both types of potential. 3 A latency time is found in photo‐induced potentials as well as in gravity‐induced ones. The Q 10 for the latency period of the photo‐induced potentials is found to be 2.8, which is the same as for the chemical part of the latency period of the gravity‐induced potentials. 4 In both cases the potential‐generating process is controlled by a Q 10 of 1.6–1.8, thus indicating this process as separate from the one mentioned above. 5 The temperature dependence of the maximum voltage follows in both cases the same pattern with a maximum at about 25–30°C.Some measurements on potential oscillations are described and discussed. The origin of the potentials is discussed.