Some metabolic responses of bush bean plants to a subherbicidal concentration of certain s-triazine compounds

Abstract

A solution containing 0.5 p.p.m. of atrazine, simazine, igran, or GS-14254 with 0.2% triton-B 1956 was applied to the foliage of 11-day-old seedlings of bush beans, Phaseolus vulgaris L. cultivar Tender-green, growing on vermiculite in a controlled environment. The activities of nitrate reductase, glutamic-pyruvic transaminase, α-amylase, starch phosphorylase, and adenosine triphosphatase were determined 5,10, and 20 days after treatment. In general, the activity of each of the five enzymes was stimulated by the treatment. The results suggest that protein increase following the application of.s-triazines to bean plants may stem in part from an enhanced rate of amino acid formation resulting from the induced increment in nitrate reductase and transaminase activity. The application of these chemicals also creates a metabolic condition favorable for greater use of carbohydrates needed for nitrate reduction and protein synthesis, and as a source of organic acid synthesis.