Characterisation of expression of the ACC oxidase gene family of apple (Malus domestica)

It is now well established in plants that ACC oxidase comprises a small multigene family of typically 4–5 members. Further, in many of the species studied, this gene family displays differential expression in response to developmental, tissue-specific stimuli, and/or environmental cues (Barry et al., 1996; Hunter et al., 1999). In apple (Malus domestica), an ACC oxidase gene that is associated with fruit ripening has been identified (Ross et al., 1992), as well as a fruit-associated isoform purified and characterised in terms of kinetic properties (Pirrung et al., 1993). However, very little is known about the other members of the gene family in apple.