The expression pattern of the Arabidopsis ACC synthase gene 1 during rosette leaf development

In Arabidopsis thaliana (L.) Heynh,, 1-aminocyclopropane-1-carboxylate (ACC ) synthase, an enzyme of the ethylene biosynthesis pathway, is encoded by a gene family that contains at least five members, The AT-ACS1 gene is regul ated in a tissue-specific manner and is induced during early development. E xpression of AT-ACS1 during rosette leaf development was analysed in furthe r detail by using a competitive reverse transcriptase PCR method to monitor transcript levels in individual leaves at different stages of rosette deve lopment. AT-ACS1 expression was the highest at leaf emergence and decreased sharply in rapidly expanding leaves, to increase again after the leaf expa nsion phase. Leaf emergence was also accompanied by an increase in ethylene production. AT-ACS1 transcript levels in rosette leaves were not influence d by the transition from the vegetative to the reproductive phase.