MOLECULAR MECHANISMS OF ETHYLENE REGULATION OF GENE-TRANSCRIPTION

Ethylene-regulated gene transcription has been studied in the context of plant defense, carnation flower petal senescence, and tomato fruit ripening. This review summarizes what is known about the molecular mec hanisms of this process. Activation of plant defense genes in response to ethylene involves a promoter element called the GCC box, which int eracts with ethylene-responsive element-binding proteins (EREBPs). Gen es expressed in response to ethylene during petal senescence and fruit ripening use different promoter elements. For fruit ripening genes, t wo cooperative promoter elements are required for ethylene-responsive transcription. DNA-binding proteins of carnation and tomato that inter act with ethylene-responsive promoter elements have been studied, and in some cases cDNAs encoding such proteins have been isolated. The imm ediate goal of this work is to determine which DNA-binding proteins ar e involved in mediating ethylene-responsive gene transcription, and ho w they interact with other components of the ethylene signaling pathwa y. This work will lead to a more complete understanding of ethylene si gnal transduction.