Post Doc Purdue University WEST LAFAYETTE, Indiana
Body of Abstract: The phytohormone ethylene controls plant growth and stress responses. Dark-grown Arabidopsis seedlings exposed to ethylene exhibit dramatic growth reductions, yet rapidly return to their basal growth rate upon removal of the gas. However, the underlying mechanism governing this acclimation to ethylene in dark-grown seedlings remains enigmatic. In this study, we report that ethylene triggers 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 stabilizes the ETHYLENE-INSENSITIVE3 (EIN3) transcription factor by interacting with and inhibiting EIN3-BINDING F-box (EBF) proteins, enhancing the ethylene response, and delaying growth recovery. Furthermore, Arabidopsis plants with enhanced nuclear-localized CTR1 exhibit improved tolerance to drought and salinity stress. These findings uncover a mechanism of the ethylene signaling pathway that links the spatiotemporal dynamics of cellular signaling components to physiological responses.