Fig. 1

Cold tolerance achieved by AB. After germinating at room temperature (21 °C) for 3 days, rapeseed seedlings were kept at 21 °C or exposed to cold stress condition (4 °C) with or without 1 mg L.⁻¹ AB treatment for another 3 days. Afterwards, corresponding photographs were taken (A). Meanwhile, the length of shoots (B) and roots (C), the diameter of stems (D), fresh weight of 50 plants (E), RWC (F), and chlorophyll content (G), were also determined. The error bars represent the SD. The different letters indicate significantly different values (P < 0.05 according to Turkey’s multiple range test)