in leaves of grape plants sprayed with H
O ( filled circles ) and SA ( open circles ) at normal growth temperature (NT, 25°C), and treated with H
O ( filled triangles ) and SA ( open triangles ) under heat stress (HT, 43°C) and recovery. Each value is the mean ± SE of 4 replicates. 0.1 mM SA solution or H2O was sprayed at 9:30 h on Day 1, immediately afterwards photosynthesis and chlorophyll fluorescence parameters were measured. Heat stress was from 9:30 to 14:30 h on Day 2. The recovery period was from 14:30 h on Day 2 to 9:30 h on Day 6. At the same time point, numerical values with different letters are significantly different (P < 0.05).