Accelerated ethylene production by a microsomal membrane fraction from carnation petals in vitro

Incubation of microsomal membranes in the presence of 1-aminocyclopropane-1-carboxylic acid (ACC) resulted in a continuous rise in the rate of ethylene production and a parallel increase in the ACC content of the membrane pellet. The rate of ethylene production was temperature dependent, being very low at 4°C. Upon transfer to the optimum temperature of 30°C, a high rate of ethylene production was measured. In fact in the latter the rate of production was higher than that measured with microsomal membranes incubated continuously at 30°C. The increase in the rate of ACC conversion to ethylene was enhanced upon disruption of the membrane by subjecting them to either a repeated freeze-thaw procedure, sonication or treatment with the non-ionic detergent Triton X-100. The results collectively suggest that penetration of ACC into the microsomal vesicles is the rate-determining factor in the conversion of ACC to ethylene.