D1
Rapeseed D1 were planted in the plant chamber under 22  (10 h/14 h, light/dark). When the plants have five leaveshalf of the seedlings were moved into 4 plant growth chamber for cold acclimation for 3 days, and then the plant growth chamber was imposed at 2 , 0 , -2  for 1 hour, respectively. The sample was collected after 1 hour under -2 .