Plant Growth-Regulating Activities of 3-Hydroxy-5-Methylisoxazole : II. Effect of 3-hydroxy-5-methylisoxazole on the geotropic response of rice seedlings

[摘要] The results of the investigation showed that 3-hydroxy-5-methylisoxazole (HMI) accelerated the geotropic response of rice seedlings. In general, the horizontally placed rice seedlings gradually revert to a nearly vertical positon. This response to gravity is referred to as the geotropic curvature of rice seedlings. The extent of this response by rice seedlings is important in determining their physiological status which influences future growth and development. The HMI-treated seedlings had a high geotropic curvature response. The effect of HMI on the geotropic curvature could also be observed when untreated control seedlings were soaked in HMI solution. The rate of geotropic curvature response of rice seedlings increased with increasing HMI dosage. HMI showed no auxin activity in the rice lamina joint test. However, the auxin activity of indoleacetic acid was increased in the presence of HMI. Therefore, the increased geotropic curvature response of rice seedlings caused by HMI may be due to a synergistic effect of HMI on endogenoud auxin.

[学科分类] 农业科学（综合）