Figure 1. The ctr1–8 mutant shows a mild constitutive ethylene response phenotype. The constitutive ethylene response phenotypes are shown for wild type (Col-0), ctr1–1, ctr1–2, and ctr1–8. a. Etiolated seedlings of air-grown ctr1–8 show weaker hypocotyl growth inhibition than ctr1–1 and ctr1–2. Ethylene treatment inhibits the seedling hypocotyl elongation of each genotype to a similar level. b. Light-grown seedlings show stronger growth inhibition in cotyledons and roots for ctr1–1 and ctr1–2 than ctr1–8. c. At the adult stage, ctr1–8 produces a much larger rosette than ctr1–1 and smaller rosette than the wild-type plant.