Effect on the tolerance to lithium chloride of deletion of the HAL3 gene in wild-type, ppz1Δ, ppz2Δ, and ppz1Δ ppz2Δ backgrounds. PPZ1 PPZ2 (A), ppz1Δ PPZ2 (B), PPZ1 ppz2Δ (C), and ppz1Δ ppz2Δ (D) cells, carrying a wild-type (+) or deleted (−) HAL3 gene as indicated, were grown at 28°C on YPD medium containing the indicated concentrations of lithium chloride. Growth was scored after 3 days.