Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Illinois.
Plant Physiol. 1966 Jan;41(1):59-65. doi: 10.1104/pp.41.1.59.
The effect of phototropic stimulation of Zea coleoptile tips on the distribution of both endogenous indoleacetic acid (IAA) and applied C(14)-labeled IAA was determined. The tips rested on bisected agar blocks. More IAA was found in the blocks under the shaded side of the coleoptile tips than those under the irradiated side. However, no significant difference was observed between the total amounts of IAA, endogenous or labeled, in the irradiated and shaded sides of the experimental system. In addition, less endogenous auxin was found in the shaded tissues than in their irradiated counterparts. It is suggested that phototropism following unilateral irradiation with first positive radiant densities might be a consequence of lateral inequalities in the ability of the irradiated and shaded tissues to transport auxin basipetally.
测定了玉米胚芽鞘尖端向光刺激对内源吲哚乙酸(IAA)和外加 C(14)-标记 IAA 分布的影响。尖端放在琼脂块的中剖面上。在胚芽鞘尖端的遮光侧发现的 IAA 比照射侧多。然而,在实验系统的照射侧和遮光侧的内源 IAA 或标记 IAA 的总量之间没有观察到显著差异。此外,在遮光组织中发现的内源生长素比照射组织中的少。有人认为,用正辐射密度单侧照射后产生的向光性可能是由于照射组织和遮光组织向基运输生长素的能力存在侧向差异的结果。