摘要：A system was developed for the detection and analysis of mutations occurring on chromosomal DNA in plants. The plasmid pML4, carrying the Escherichia coli rpsL gene, a target gene for mutagenesis, was inserted into a shuttle vector, pCGN5138, to construct a plasmid which could be used for the transformation of plants. pML4 sequences were introduced into Arabidopsis thaliana mediated by Agrobacterium . The pML4 DNA was rescued from transgenic Arabidopsis plants exposed to mutagens, and the plasmids were introduced into Escherichia coli DH10B to isolate mutant clones. In this system, any form of inactivation mutation in the rpsL gene can be positively selected since it makes the E. coli cells resistant to streptomycin. Here we report that the system could detect the mutagenic effect of ethylmethanesulfonate (EMS). Further characterization of the mutants revealed that G:C to A:T transitions predominated among the EMS-induced mutations. This assay system is useful for the detection and analysis of mutations arising on chromosomal DNA in plants, and should be useful for evaluating analysis of the effects of environmental mutagens.
