FIG. 5.

Growth inhibition of S. cerevisiae BY4741 MATa (BY4741/a) and single deletion mutants of genes that constitute the HOG pathway or are known to regulate or be regulated by the HOG pathway. (a) Cultures were grown to late exponential phase in ME medium (pH 3.5) in the presence or absence of 300 mM citric acid. For each strain, growth inhibition is expressed as the percent inhibition of growth rate. This was calculated by measuring the growth rate in the presence or absence of 300 mM citric acid and expressing the additional inhibition seen in the citric acid-treated culture relative to the untreated culture as a percentage. Three replicate experiments were performed. The values are shown as the means ± standard deviations (error bars) of the three experiments. (b) Complementation of the Δhog1 citric acid-sensitive phenotype. Growth inhibition of S. cerevisiae BY4741 MATa (BY4741/a), Δhog1 mutant, and Δhog1 mutant carrying pRS313::HOG1 is shown on ME agar (pH 3.5) and ME agar (pH 3.5) plus 200, 300, and 400 mM citric acid (CA). A representative result is shown.