Ethylene receptor (ETR) (ETR)

Plant ethylene receptors are a family of membrane-bound proteins, primarily located in the endoplasmic reticulum, that mediate the response to the gaseous hormone ethylene (Chen et al., 2002, PubMed: 11884530). In the model plant Arabidopsis thaliana, this family consists of five members—ETR1, ETR2, ERS1, ERS2, and EIN4—which function as negative regulators of the ethylene signaling pathway (Hua and Meyerowitz, 1998, PubMed: 9660874). In the absence of ethylene, these receptors are active and maintain the signaling pathway in an "off" state by activating the kinase CTR1; upon binding ethylene, the receptors are inactivated, leading to the relief of CTR1-mediated inhibition and the subsequent activation of the EIN2 and EIN3/EIL1 transcription factor cascade (Ju et al., 2012, PubMed: 22932631). These receptors are critical targets in agriculture and horticulture for controlling processes such as fruit ripening, flower senescence, and leaf abscission. Commercial compounds like 1-methylcyclopropene (1-MCP) act as potent inhibitors by binding irreversibly to the ethylene-binding site, thereby extending the shelf life of various produce (Sisler and Serek, 1997, PubMed: 9230557). Understanding these receptors is essential for developing biotechnological strategies to improve crop yield and post-harvest stability under various environmental stresses.

Other names

ETR1ETR2ERS1ERS2EIN4Ethylene response 1Ethylene-binding protein

The receptors function as negative regulators of the ethylene signaling pathway; binding of ethylene or inhibitors like 1-MCP suppresses receptor activity, thereby inactivating the associated CTR1 kinase and allowing downstream signaling to proceed.