Figure 1.

Expression of the ETR1 N terminus partially suppresses constitutive ethylene responses mediated by ctr1-1. A, Structure and mutations of ETR1 and CTR1 isoforms described in this study. TM, Transmembrane domain. B, Seedling hypocotyl length of ctr1-1 and ctr1-1 expressing etr1-1^1-349 or etr1^1-349. C and D, Phenotype (C) and hypocotyl length (D) of etiolated seedlings of ctr1-1 and etr1-1 ctr1-1. E, Rosette phenotype of ctr1-1 and etr1-1 ctr1-1. F and G, Phenotype of light-grown seedlings (F) and rosettes (G) of ctr1-1 and ctr1-1 expressing etr1^1-349 or etr1-1^1-349. H, ERF1 expression in ctr1-1 and ctr1-1 expressing the ETR1 N terminus. I and J, Measurement of the relative transgene expression for etr1-1^1-349 (I) and etr1^1-349 (J) of corresponding ctr1-1 transformation lines. etr1^1-349 and etr1-1^1-349 denote the etr1^1-349 and etr1-1^1-349 transgenes, respectively, that are driven by the native ETR1 promoter. L indicates the transformation lines used in this assay. Data are means ± sd (n ≥ 30). ** P < 0.01 by Student’s t test. [See online article for color version of this figure.]