Rates of production and internal levels of ethylene in the vegetative cotton plant1

摘要

The internal levels of ethylene in and the production rates of ethylene by various parts of the cotton plant {Gossypium hirsutumL. cultivar Acala 4–42) were determined by separate techniques. Wounding of tissue, which resulted from both techniques, increased ethylene production. A peak in wound-induced ethylene occurred around the second to third hour after wounding and gradually declined until the sixth or seventh hour when ethylene production began to level off. Using two techniques, with numerous observations from each technique, ethylene levels were found to be relatively uniform throughout the vegetative cotton plant. There was a small trend for levels of ethylene to increase from the bottom (oldest tissue) to the top of the plant (youngest tissue). Of major interest was the observation that the production rates and internal concentrations of ethylene in the petiole were two to six times higher than those in the leaf blade. This relative concentration of ethylene in the petiole supports the hypothesis that ethylene is a natural regulator of abscission which acts, in part, through modification of auxin transpor