Expression levels of (A) AtCBF1 (DREB1B), (B) AtCBF2 (DREB1C) and (C) AtCBF3 (DREB1A) genes and (D) COR15A, (E) COR47 and (F) RD29A downstream genes in 7-day old AtRAN1-OE, the atran1-1 atran3 mutant and wild-type plants under before and after freezing treatment. Values are means and SD (n = 4). Expression of (G) MCM2, (H) MCM5, (I) Cycb1;1, (J) Cyca3;1, (K) Cycd3;1, (L) Cdkb1;1, (M) Cdkb2;1 and (N) Cyca2;1 cell cycle-related gene levels in wild-type, atran1-1 atran3 mutant and transgenic plants before and after 0.5h freezing stress, after 4°C acclimation, The error bars show SD, and are from three independent replications. And the results were repeated three times. Asterisk (*) indicates significant difference (P < 0.05).