Chemical and biochemical aspects of the biosynthesis of ethylene, a plant hormone.

Ethylene is a plant hormone which controls numerous aspects of the growth and development of plants. Plants produce ethylene starting from methionine via 1-aminocyclopropanecarboxylic acid (ACC). Two key enzymes take part successively in the course of this transformation: ACC synthase, which is now well known, and ACC oxidase, the mechanism of action and the structure of which are still being studied. In this article we assemble and analyze the chemical and biochemical aspects of the biosynthesis of ethylene and describe studies directed towards the rational design of new classes of regulators of plant growth. These investigations may have commercial importance if they lead to prolonging the viable life of fruit after harvesting or allow the modification of other processes, such as abscission, controlled by ethylene. In humanitarian terms, the impact on agricultural zones lacking refrigerated storage or an effective means of maintaining foodstuffs after harvest may be more important and more worthy of interest. The loss of foodstuffs due to deterioration and mould growth after harvest remains a universal problem both for developed and under-developed countries.