Figure 3.

Radish root segments cultured in MS and IAA, or IAA prereacted with AAO and then filter-sterilized and added to cultures. A, Effect of increasing concentrations of IAA. As the concentration is increased, tip growth becomes inhibited and lateral root frequency increases. B, Effects of IAA prereacted with increasing amounts of AAO. As AAO units are increased, inhibition of tip growth and lateral root frequency are decreased. C, Representative repetition of the effect on roots in culture with IAA pretreated with 5 units of AAO. The original tip region of the root before elongation growth in culture is marked by the swollen cortical region located proximally about one-third the distance to the present tip. D, Radish root segments cultured with 3 μm IAA reacted with 5 units of AAO previously boiled to denature the protein.