TRADESCANTIA STAMEN HAIR MUTATION BIOASSAY

The Tradescantia stamen hair mutation (Trad-SH) assay (clone 4430) was evaluated for its efficiency and reliability as a screen for mutagens in an IPCS collaborative study on plant systems. Four coded chemicals, i.e. azidoglycerol (AG, 3-azido-1,2-propanediol), N-methyl-N-nitrosourea (MNU), sodium azide (NaN3) and maleic hydrazide (MH) were distributed by the Radian Corporation to the five laboratories in five different countries for testing mutagenicity. Pink mutations were scored between the 7th and 14th day according to a standard protocol. Test results from the five individual laboratories were analyzed and compared after decoding. One out of the two laboratories that conducted tests on AG demonstrated that AG is a mutagen with genetically effective doses ranging from 50 to 100 mu g/ml. MH yielded positive responses in all laboratories but no linear dose-response pattern was observed. The effective dose range for MH was between 1 and 45 mu g/ml. The mutagenicity of MNU was reported by five laboratories in the dose range between 10 and 80 mu g/ml. NaN3, which exhibited a relatively high degree of toxicity, elicited a positive mutagenic response in three of the five laboratories in which it was tested. As with MNU the effective dose for NaN3 ranged between 3 and 80 mu g/ml. The results from the current study substantiate the Trad-SH assay as a reliable system for screening chemicals for their potential mutagenic effects. Although the study was carried out exclusively under laboratory conditions, a survey of the current literature would indicate that the Trad-SH assay could be an effective in situ monitor of gaseous, liquid, and radioactive pollutants as well.