Abstract
For investigations of the possible mechanism of action of ethylene, intact mitochondria with respiratory control were prepared from bean cotyledons of various ages. Ethylene treatment resulted in an increase in the rate of mitochondrial volume change caused by ADP or ATP, but was without effect on spontaneous changes or those mediated by phosphate or calcium ions. This suggested that ethylene affects an enzyme with which the nucleotides react and which is associated with mitochondrial volume changes. Such an enzyme is mitochondrial ATP, and it was found that ouabain, known to be an inhibitor of this enzyme in some cotyledons, prevented tha response to ethylene.