Simulation of acetylcholine action by {beta}-indole acetic acid in inducing diurnal change of floral response to chilling under continuous light in Lemna gibba G3

IAA induced a diurnal change in floral response to chillingof Lemna gibba G3 under continuous light, as has been reportedfor ACh. This IAA effect was antagonized by an antiauxin, T-CA.NAA and 2,4-D had no influence on the temperature sensitivityof the duckweed. ACh-like reagents were examined with respectto the sensitivity to their antagonists. Atropine, an ACh-specificantagonist, inhibited the action of IAA. The IAA treatment,however, decreased the ACh content of the plant by ca. 30%.Thus, IAA and ACh are surmised to attack the same or similaraction site(s) independently. (Received July 19, 1978; )