The transport of auxin and regeneration of xylem in okra and pea stems

Internodes were isolated from okra and pea plants grown from seed under controlled conditions. Isolated internodes were treated apically or basally with IAA-C¹⁴ or 2,4-D-C¹⁴ and several vascular bundles were severed in the middle of the internodes. Transport of auxins was basipetally polar, IAA moving with greater facility than 2,4-D. Apically applied auxin stimulated vascular regeneration in the wound area; basally applied auxin did not, but radioactivity from basally applied IAA reached the wound. This suggests that the path of transport or mode of presentation to cells is important unless basally and apically applied auxin are metabolized differently.