The effect of mechanical impedance on ethylene production by maize roots

The role of ethylene in mediating the response of primary roots of Zea mays cv. Merit to experimentally imposed mechanical impedance was examined. Root elongation was stimulated during the first 100 min of impedance. Within 300 min, impedance inhibited ethylene evolution while simultaneously stimulating 1-aminocyclopropane-1-carboxylic acid production. The root cap is not necessary for the observed impedance-mediated inhibition in ethylene, and ethylene evolution was not stimulated by excising root caps. Ethylene synthesis in roots is normally controlled by the production of 1-aminocyclopropane-1-carboxylic acid.