Botanisches Institut der Universität, Schloßgarten 3, D-4400, Münster, Federal Republic of Germany.
Planta. 1980 Nov;150(1):32-6. doi: 10.1007/BF00385611.
The effect of externally applied indoleacetic acid (IAA) and abscisic acid (ABA) on the growth of roots of Zea mays L. was measured. Donor blocks of agar with IAA or ABA were placed laterally on the roots and root curvature was measured. When IAA was applied to vertical roots, a curvature directed toward the donor block was observed. This curvature corresponded to a growth inhibition at the side of the root where the donor was applied. When IAA was applied to horizontal roots from the upper side, normal geotropic downward bending was delayed or totally inhibited. The extent of retardation and the inhibition of curvature were found to depend on the concentration of IAA in the donor block. ABA neither induced curvature in vertical roots nor inhibited geotropic curvature in horizontal roots; thus the growth of roots was not inhibited by ABA. However, when, instead of donor blocks, root tips or coleoptile tips were placed onto vertical roots, a curvature of the roots was observed.
研究了外源吲哚乙酸（IAA）和脱落酸（ABA）对玉米（Zea mays L.）根生长的影响。将含有 IAA 或 ABA 的琼脂供体块侧向放置在根上，并测量根的曲率。当 IAA 施加到垂直的根上时，观察到朝向供体块的弯曲。这种弯曲对应于供体施加侧根的生长抑制。当 IAA 从上方施加到水平根上时，正常的向地向下弯曲被延迟或完全抑制。延迟的程度和曲率的抑制被发现取决于供体块中 IAA 的浓度。ABA 既不会诱导垂直根的弯曲，也不会抑制水平根的向地性弯曲；因此，ABA 不会抑制根的生长。然而，当将根尖或胚芽鞘尖端而不是供体块放置在垂直的根上时，观察到根的弯曲。
