Molecular Basis of the Ethylene Signaling and Response Pathway in Arabidopsis

The gaseous phytohormone ethylene is a key regulator in plant growth and developmental process as well as biotic and abiotic stress response. This review focuses on the recent advances in the ethylene- signaling pathway in Arabidopsis, with particular emphasis on the latest information about the downstream events of the ethylene-response pathway. Notable new findings include identification of a specific regulator of the ethylene receptor ETR1, discovery of protein degradation and RNA turnover processes in modulating EIN3-dependent transcriptional regulation, demonstration of the involvement of auxin biosynthesis in ethylene-mediated inhibition of root growth, and determination of possible integration points between ethylene and other hormonal and environmental signals (gibberellin, jasmonic acid, light, and sugar)in various plant processes. The elucidation of the molecular mechanisms of the ethylene-signaling and ethyleneresponse pathway in Arabidopsis might provide a framework for understanding how other plant species sense and respond to ethylene.