Effect of E8 on ACO activity and ethylene production. (A) Ectopically overexpressed in vitro ACO activity was not altered by the addition of ectopically overexpressed E8. (B) The effect of a possible ACO activity inhibition was also evaluated in pericarp enzyme extracts, by mixing a sample with no E8 abundance and high ACO activity (left) with a sample containing a high E8 abundance and low ACO activity (middle), resulting in no inhibition of ACO activity (right). Error bars represent the standard deviation of 3 replicates. Statistical significant differences (P < 0.05) between treatments are indicated with A and B.