In hormone perception, varying the concentrations of hormone, receptor, or downstream signaling elements can modulate signal transduction. Previous research has demonstrated that ethylene biosynthesis in plants is regulated by abiotic factors. Here we report that exposure of Arabidopsis plants to NaCl reduced expression of the ethylene receptor ETR1. The change in gene expression was reflected at the protein level based on immunoblot analysis. Further analysis supports a general effect of osmotic stress upon the expression level of ETR1. The reduction in ETR1 levels should cause increased sensitivity of the plant to ethylene. These results suggest that plant responses to abiotic stress are modulated by changes in the expression level of ethylene receptors.