Fundamental study on in situ monitoring of environmental mutagens with Tradescantia

点击翻译按钮获取中文摘要

This study was carried out in 1993 to 1995 using the stamen hairs of Tradescantia, in order to investigate (1) the mutagenicities of alkylating agents and their synergistic effects with X rays, (2) the mutagenicity of maleic hydrazide (being used as herbicide) and its interactions with X rays, (3) the mutagenicities of air pollutants, and (4) variation of spontaneous mutation frequency, as well as to develop (5) a new testing system.As for (1), the mutagenicities of ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), dimethyl sulfate (DMS), N-ethyl-N-nitrosoures (ENU) and N-methl-N-nitrosourea (MNU) were determined, and EMS,MMS,DMS and MNU were confirmed to show clear synergistic effects with X rays. Concerning (2), maleic hydrazide (MH), a promutagen, was found to be activated into a mutagen in Tradescantia cells by peroxidase, and to act both antagonistically and synergistically with X rays when the activation of MH was inhibited and not inhibited by X rays, respectively. As for (3), treatments with nitrogen dioxide in nitrogen or air/nitrogen mixtures were conducted using a gas exposing chamber, but inconsistent results were obtained. The effect of ozone is now being investigated. About (4), a certain extent of variation in spontaneous mutation frequency due to temperature conditions was confirmed. Concerning (5), young inflorescence-bearing shoots with roots of clone BNL 4430 cultivated in the nutrient solution circulating growth chamber were found to be the most efficient materials for mutagenicity testings.