Phytotoxicity of Herbicides, Reduction of 3-Amino-1,2,4-triazole Phytotoxicity in Tomato Plants

Abstract

Reduction of 3-Amino-l,2,4-triazole Phytotoxicity in Tomato PlantsThe phytotoxicity of 3-amino-1,2,4-triazole was studied using tomato plants to determine the efficacy of selected compounds in reducing growth and chlorophyll toxicities. When the concentration of 3-AT was 1 X 10-4M, equimolar solutions of certain purine precursors simultaneously applied caused a reduction of 3-AT growth inhibition; but this did not occur when all concentrations were five times this amount. Adenine, hypoxanthine, and guanine and their ribosides acted like the purine precursors. Riboflavin, FMN, and FAD reduced not only 3-AT growth inhibition at 5 X 10-4M, but also the inhibition of chlorophyll formation. A hypothesis of the mechanism of 3-AT phytotoxicity is presented.

Effect of Administration of 3-Aminotriazole on the Activity of Microsomal Drug-Metabolizing Enzyme Systems of Rat Liver

“…The administration of phenobarbital increased the activity of drug metabolism as well as content of P-450 in liver microsomes (4-6, 9, 10). On the other hand, the admi nistration of 3-aminotriazole depressed the activity of liver and kidney catalase and liver peroxidase and depressed biosynthesis of chlorophyl (13)(14)(15)16). However, detailed mechanism by which the activity of catalase was depressed is not yet elucidated.…”

Riboflavin Nullification of Inhibitory Actions of 3-Amino-1,2,4-Triazole on Seedling Growth

“…adenine. Reduction of amitrole toxicity by purines is usually small in comparison to reductions obtained with riboflavin or histidine but theylhave been reported for three species of higher plants (1,22) and one species each of yeast (13), algae (24), and bacteria (23). These observations may be interpreted as evidence either A, that amitrole is a general inhibitor of purine utilization or B. that amitrole inhibits the biosynthesis of purines.…”

Histidine Biosynthesis

“…Aminotriazole inhibition of growth can also be relieved in tomatoes (Sund et al, 1960) and algae (Wolf, 1962) by adenine and related nucleotide bases but histidine alone appears to be relatively inefiFective in a range of chlorophyllous plants (Hilton, 1969) suggesting that the herbicide has multi ple sites of action.…”