1. トウモロコシ幼葉鞘先端における赤色光照射によるIAA生合成の抑制

概要

論文の詳細を見る
The plant hormone auxin (indole-3-acetic acid (IAA)) plays an important role in physiological responses such as gravitropism and phototropism. We reported that in maize coleoptiles the main site of IAA biosynthesis is 0-2mm tip region and the produced IAA moves constantly to the lower part. It has been reported that red light irradiation to the coleoptiles caused the reduction of the IAA level in the tip region and therefore the diffusible IAA from the tip to the lower parts was also decreased. In the present work, to investigate the mechanism(s) for the IAA reduction by red light irradiation we examined free and conjugated IAA levels, and rate of IAA transport. IAA was extracted by an improved method using Micro-Smash (TOMY) and determined with GC-SIM-MS. The results revealed that the red light did not cause any changes in the amount of conjugated IAA and the rate of polar transport, indicating that red light suppresses the rate of IAA biosynthesis in the coleoptile tip.
2005-10-13