Ethanol enhances the drought tolerance of the adh1 mutants, but not the aldh triple mutant. Two-week-old A. thaliana adh1 and aldh triple mutant (aldh2b4/aldh2b7/aldh2c4) plants were treated with 10 mM ethanol for 3 d and then subjected to drought stress. (A, C) The adh1 (A) and aldh triple mutant (C) plants were photographed at 4 d after rewatering. (B, D) Survival rate (%) of the adh1 (B) and aldh triple mutant (D) plants. (E, F). Two-week-old aldh triple mutant plants were treated with 10 mM acetic acid for 3 d and then subjected to drought stress treatment. (E) Plants were photographed at 4 d after rewatering. (F) Survival rate (%) of the aldh triple mutant plants. Asterisks indicate significant differences (compared with the control) according to the SNK test (P < 0.05; n = 3).