Figure 9.

OsABI5 acts downstream of OsSAE1 to regulate salt tolerance in rice seedlings. A, Phenotypes of Nip, ossae1, osabi5, and sae1abi5 double mutants under salt stress. The images of the plants were digitally extracted for comparison. B, Survival rates of the plants shown in (A), 7 d after stopping salt stress. Approximately 50–60 seedlings were used per experiment. Data show mean ± sd of three independent replicates. Asterisks indicate significant differences compared to Nip at *P < 0.05 and **P < 0.01 by Student’s t test. C and D, Expression of SOS1 (C) and LEA3 (D) in Nip, ossae1, osabi5, and sae1abi5 double mutant seedlings with or without salt treatment. Ten DAI seedlings were treated with or without 150-mM NaCl for 6 h. RNA was isolated from shoots and used for RT-qPCR. Actin1 was used as an internal control. The relative expression levels were represented by fold change relative to the expression levels of Nip-control. E and F, MDA (E) and H₂O₂ (F) contents in leaves of 10 DAI seedlings with or without 150-mM NaCl treatment for 3 d. For (C, D, E, and F), the error bars indicate the sds based on three independent replicates, different letters indicate significant differences (P < 0.05, one-way ANOVA with Tukey’s test).