Genomic profile of roundup treatment of yeast using DNA microarray analysis

The herbicide Roundup, which contains glyphosate as the active ingredient, was first introduced in 1974 and has enjoyed widespread use in Japan and elsewhere in the world. Roundup-induced reactions occurring in the yeast Saccharomyces cerevisiae may have a predictive value for understanding responses in higher eukaryotes, and we applied yeast DNA microarray analysis for this purpose. Functional characterization of up-regulated open reading frames (ORFs) following Roundup treatment suggests that Roundup affects membrane structures and cellular organelles. Expression profiles induced by treatments with detergents, oils and hydrostatic pressure were similar to those following Roundup treatment based on cluster analysis. Glyphosate alone was not found to inhibit yeast growth at the concentration contained in the Roundup treatment used for microarray analysis. The toxicity of Roundup appeared to be due to detergent in the product.