The study of the ethylene status of the pea mutant SGEcrt, which is characterized by a modified morphology of the root system (whose development depends considerably on physical and mechanical environmental conditions), was carried out. The dependence of the manifestation of the mutant root system phenotype on the plant’s ethylene status was confirmed. It was demonstrated that the mutant is characterized by increased production and increased sensitivity to ethylene against a background of a violation in ethylene biosynthesis regulatory mechanisms, resulting in an increased activity of the ethylene-producing enzyme ACC-oxidase.