Fig. 4.

SmAP2-17-overexpression transgenic lines did not show increased tolerance to salt stress. a SmAP2-17-overexpression transgenic line T-15 had a delayed germination phenotype under salt stress compared to the WT (wild-type) at 48 h and 72 h after sowing. b Statistical analysis of the germination rate of WT and transgenic lines T-15 and T-1 at 72 h after sowing under different concentrations of NaCl (75 mM NaCl, 100 mM NaCl, and 150 mM NaCl). c qRT-PCR analysis of the expression levels of SmAP2-17 in WT and transgenic lines T-1 and T-15 under normal conditions and after treatment with 100 mM NaCl. c-f Physiological indices of transgenic and WT Arabidopsis seedlings under normal and salt stress conditions. The MDA content (c) and antioxidant enzyme activities, including peroxidase (d), catalase (e), and superoxide dismutase (f), were measured in WT and transgenic lines T-15 and T-1 under normal and salt stress conditions. Two-week-old seedlings were exposed to 200 mM NaCl for 4 d before the measurements. g qRT-PCR analysis of the expression levels of SmAP2-17 in WT and transgenic lines T-1 T-3, and T-15 under normal and salt stress (100 mM) conditions. Data represent the mean of three replicates, and the error bars indicate the SD; *P < 0.05 and **P < 0.01 by Student’s t-test