vacuumized

— Except for the cold stress at 4°C, other treatments were conducted in a growth chamber with cycles of 8h light (~150 μEm -2 sec -1 ) and 16h dark at 22±2°C. After 24h treatment, the plants were sampled and vacuumized for 10min and incubated at 37°C overnight in the GUS solution (10mL solution: 3mL 0.2M NaH 2 PO 4 ·H 2 O, 6mL 0.2M Na 2 HPO 4 ·2H 2 O, 200μL 100mM X-Gluc stock, 1mL methyl alcohol).