Phytochrome Control of Maize Coleoptile Section Elongation

Abstract
A rapid loss of far red light (FR) reversibility of red-light (R) stimulated elongation of maize coleoptile sections was observed. Reversal was not possible when the interval between R and FR treatment was greater than 45 s. Most R-stimulated elongation occurred during the first 15 h after irradiation. Exogenous GA3 did not alter the time course of R/FR reversibility loss. Independence of R- and GA3-stimulated elongation in this system was indicated.