Short communication Effects of Glyphosate on Caffeic Acid Metabolism in Perilla Cell Suspension Cultures

Perilla cell suspension cultures contained caffeic acid at 0.073 % of the fresh weight. When 1 min glyphosate was administered to the cell culture in the logarithmic and stationary phases, the amount of caffeic acid ceased to increase and remained at a nearly constant level during the following several days. Phenylalanine ammonia-lyase (PAL) activity in the cell culture increased immediately after transfer to a fresh medium, decreased rapidly in the midst of the logarithmic phase and became almost undetectable in the stationary phase. PAL activity was markedly inhibited by glyphosate at more than 0.2 mM. The shikimic acid content of cells from 14-day culture grown in the presence of 1 miw glyphosate increased up to 74.9 /ig per g fresh weight during 6-day culture, whereas that of the control cells was undetectable. The dosage of 0.15 mM L-2-aminooxy-3-phenylpropionic acid (L-AOPP), an inhibitor of PAL, to the cells did not cause shikimic acid accumulation. Key words: Caffeic acid — Glyphosate — Perilla cell culture — Phenylalanine ammonia-lyase — Shikimic acid. The effects of the broad-spectrum herbicide glyphosate (N-fphosphonolnethylJglycine) o