Elongation and Gravireactivity of Roots from an Agravitropic Maize Mutant: Implications of Growth Inhibitors

Growth of agravitropic (AGT) mutant (c.v. Kys) maize roots wassignificantly higher in comparison to that of two normal gravitropiccultivar roots. Vertical halfdecapitated roots bent towardsthe remaining half tip. This result can be explained by thefact that cap cells produced growth inhibitors (GI) moving inbasipetal direction. The curvatures of half-decapitated rootsin Kys AGT root were significantly smaller than in normal cultivarroot. One essential consequence of this AGT mutation was broughtby low GI content inside the extension zone. ¹ In honour of Professor J. Ashida (Received August 27, 1982; Accepted January 17, 1983)