PLANT METABOLIC STUDIES OF THE GROWTH-REGULATOR MALEIC HYDRAZIDE

The metabolism of maleic hydrazide has been studied in cell suspension cultures of soybean, wheat, and maize under standardized conditions ( 40 mt flasks, I ppm, 48 h). Maleic hydrazide was converted to its beta -D-glucoside as the predominant soluble metabolite in yields of betwee n 2 and 15%. The latter was completely cleaved under simulated stomach conditions (pH 1, 37 degrees C, 24 h). In addition, up to 18% of the applied maleic hydrazide became associated with the nonextractable res idue. The residue from soybean cells was solubilized only to a low deg ree (similar to 3%) under simulated stomach conditions. The lignin and hemicellulose components appeared to contain most of the radioactivit y in the nonextractable residue from soybean cells. It is concluded th at metabolism in Cultured plant cells resembled that in whole plants a nd that the beta-D-glucoside of maleic hydrazide belongs to the small group of acid-labile pesticidal conjugates.