<i>L</i>-2-Oxothiazolidine-4-Carboxylic Acid Protection Against Tridiphane Toxicity

Abstract

Tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane] inhibited growth of seedling corn ( Zea mays L. ‘DK T 1100’), wheat ( Triticum aesetivum L. ‘Arthur’), and sorghum ( Sorghum vulgare Pers. ‘DK 42Y’) in growth chamber experiments. These inhibitions were partially circumvented by simultaneous treatment with OTC ( L -2-oxothiazolidine-4-carboxylic acid). Tridiphane, atrazine [6-chloro- N -ethyl- N′ -(1-methylethyl)-1,3,5-triazine-2,4-diamine], and OTC each increased levels of low molecular weight thiols (glutathione) in intact roots of treated corn seedlings, but only OTC did in excised roots. Tridiphane and atrazine caused a decrease in thiol content of excised roots. Tridiphane treatments reduced the amount of glutathione S -transferase activity extractable from corn roots, and this reduction was circumvented partially by OTC applied in combination with tridiphane. These data present evidence that tridiphane interference with cysteine or glutathione metabolism can be reversed by increasing cellular content of cysteine.