Abstract
The gaseous plant hormone ethylene plays an essential role in a number of developmental processes, including seed germination, seedling growth, leaf and petal abscission, fruit ripening, and senescence. 1-Aminocyclopropane-1-carboxylic acid synthase (ACS) is a key enzyme in the ethylene biosynthetic pathway, and its activity increased in response to endogenous and exogenous factors. In fruit, different ACS isogenes are induced and are responsible for differences in ethylene production among cultivars. ACS is phosphorylated in vivo, and phosphorylation confers protein stability. Ethylene is perceived by ethylene receptors, many of which have been identified and are known to be negative regulators of ethylene signaling. This review focuses on transcriptional and post-translational regulation of ACS. Furthermore, the effect of ethylene on the stability of ethylene receptors in apple is described.
