1-Aminocyclopropanecarboxylic acid (1, Acc) holds a prime position in plant physiology as it is oxidatively decarboxylated by the so-called" ethylene-forming enzyme"(EFE) to produce ethylene 3 (Scheme I). l Ethylene is a major plant hormone involved in regulating a number of important physiological processes including germination, ripening of fruits, abscission of fruits and leaves, and senescence. In recent years, the mechanism of the biochemical ...