Ethylene-triggered subcellular trafficking of CTR1 suppresses the response to ethylene gas

Ethylene gas controls plant growth and stress responses. Ethylene-exposed dark-grown seedlings exhibit a dramatic growth reduction, yet the seedlings rapidly return to the basal growth rate when ethylene gas is removed. However, the underlying mechanism governing this remarkable reversible acclimation of dark-grown seedlings to ethylene remains enigmatic. Here, we report that ethylene triggers the translocation of the Raf-like protein kinase CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), a negative regulator of ethylene signaling, from the endoplasmic reticulum to the nucleus. Nuclear-localized CTR1 inhibits the ETHYLENE-INSENSITIVE3 (EIN3) transcription factor via the EIN3-BINDING F-box Proteins, resulting in rapid suppression of the ethylene response, thus promoting fast growth recovery. These findings uncover a mechanism of the ethylene signaling pathway that links the spatiotemporal dynamics of cellular signaling components to organismal responses.