TY - JA AU - Pilet,P.E. AU - Rivier,L. TI - Light and ark georeaction of maize roots: effect and endogenous level of abscisic acid U1 - 81-586261 PY - 1980/// KW - Maize KW - AGROVOC KW - Zea mays N1 - 24 ref.; Summary (En) N2 - An ABA pretreatment enhanced the geotropism of maize (cv. LG 11) root segments. Such stimulation was much stronger for georeacting roots in darkness. When ABA was applied asymmetrically on the lower part of the apical cut end of decapped segments, it induced a downward curvature which increased with increasing ABA concentration. Using the GC/MS technique, ABA was found in the root tip: the light exposed roots containing more ABA than those kept in darkness. But no changes in the total ABA level were obtained between vertical and horizontal segments. This indicates that the increase in the growth inhibitor amount in the lower part of the T2 - Plant Science Letters ER -