Fig. 8.

Drought, salt, and freezing stress tolerance of wild type and NtLEA7-3-overexpressing transgenic Arabidopsis plants. The stress treatments were performed as follows: Control: 6-week-old plants growing under normal conditions; Drought stress (A): water withheld for 2 weeks; Salt stress (B): plants soaked in the nutrient solution was supplemented with NaCl with increasing concentration from 50 through 100, and 150 to a final 200 mm for 4 d at each concentration. Freezing stress (C): plants exposed to 4 °C for 1 d and then subjected to a series of temperature from 0 °C through −2 °C, −4 °C, −6 °C and −8 °C to a final temperature of −10 °C for 2 h at each temperature and returned to 22 °C for 5 days; WT: Wild type plants; OE: Transgenic plants.