Effect of kinetin on auxin uptake and distribution in normal and tumor-prone Nicotiana shoots

Stem segments of non-tumorous Nicotiana glauca and N. langsdorffii plants and of their tumor-producing amphidiploid F1 hybrid were treated with 6-furfurylaminopurine (kinetin) prior to transport tests with applied labeled indoleacetic acid (IAA-2-14C). Kinetin-treatments increased the uptake of IAA in non-tumorous shoots; the IAA uptake by N. langsdorffii segments was increased up to 3-fold. The auxin uptake in stem-segments of the tumor-forming hybrid, however, could not be increased significantly by kinetin. The even distribution of IAA-14C in segments of normal and tumorprone Nicotiana shoots is stimulated by kinetin. Data are discussed in conjunction with previous results on auxin transport and tumorformation in Nicotiana.