Induction of somatic mutations in Tradescantia clone 4430 by three phenylenediamine isomers and the antimutagenic mechanisms of diethyldithiocarbamate and ammonium meta-vanadate.
Three isomers of the promutagen phenylenediamine at mM concentrations were plant-activated and induced mutation in stamen hairs of Tradescantia clone 4430. The rank order of the mutagenicity of the isomers was: o-phenylenediamine > m-phenylenediamine > p-phenylenediamine with corresponding mutagenic potencies of 5.60, 1.43, and 0.46 mutant stamen hair cells/mumole, respectively. Diethyldithiocarbamate (DEDTC) and ammonium meta-vanadate (vanadate) repressed the mutagenic activity of o-phenylenediamine (o-PDA) in intact plants. Based on inhibition kinetics and reaction rates, the mechanism of DEDTC antimutagenicity was attributed to the inhibition of peroxidases that are required in the plant activation of o-PDA to mutagenic product(s). Spectrophotometric measurements of equimolar concentrations of o-PDA and vanadate demonstrated that the antimutagenic property of vanadate was mainly due to its reactivity with o-PDA.
Gichner
T
T
Institute of Experimental Botany, Prague, Czech Republic.
Cabrera Lopez
G
G
Wagner
E D
ED
Plewa
M J
MJ
D004050:Ditiocarb / Q000031:analogs & derivatives / Q000494:pharmacology*; D009153:Mutagens; D010655:Phenylenediamines / Q000633:toxicity*; D010944:Plants / Q000235:genetics; D014638:Vanadates / Q000494:pharmacology
D009153:Mutagens; D010655:Phenylenediamines; D014638:Vanadates; C034193:1,2-diaminobenzene; D004050:Ditiocarb; C039353:dihydroxyethyldithiocarbamate; C008381:3-phenylenediamine; C029728:4-phenylenediamine