Differential drought physiological traits of H471, P28, and HHZ. (A) Water loss rate of P28, HHZ, and H471. For each replicate, 15 fully expanded leaves at the tillering stage were used in a triplicate experiment. (B) Relative water content of HHZ, P28, and H471 treated with 3 days of natural drought using the fully expanded leaves. (C) The stomatal closure rate in HHZ, P28, and H471 (upper epidermis: 6 randomly selected high power field for HHZ; 5 for P28; 6 for H471; lower epidermis: 8 randomly selected high power field for HHZ; 6 for P28; 6 for H471). (D) Relative electrolyte leakage of HHZ, P28, and H471 after 3 days of drought stress. (E), (F) Activity of ROS-scavenging enzymes (CAT and APX) in three rice genotypes subjected to drought stress. Each column represents mean ± s.d. (three replicates); **p <0.01; *p <0.05 versus HHZ (ANOVA, Dunnett’s multiple comparison test).