AbstractConversion of 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene was studied in submitochondrial particles (SMP) which were prepared by sonication of the mitochondrial fraction isolated from 7-day-old etiolated pea (Pisum sativum var. Kelvedon Wonder) seedlings. The reaction was enhanced by the addition of Mn2+ and had a maximal rate at pH 8.0. Conversion of ACC to ethylene was inhibited under anaerobic conditions and by the addition of KCN, EDTA, NaN3, n-propyl gallate and CoCl2. Addition of the uncouplers 2,4-DNP, CCCP and FCCP, however, did not inhibit the reaction. Structural analogs of ACC inhibited ACC conversion to enthylene by SMP. The structural analog of methionine, α-keto-γ-methylthiobutyric acid (KMB), was converted to ethylene by SMP at a rate which was only about 2% that of ACC conversion to ethylene
