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<i>Malus baccata</i> (L.) Borkh is an apple rootstock with good drought and cold resistance. The ICE gene is a key factor in the molecular mechanisms of plant drought and cold resistance. In the present research, the function of drought- and cold-induced <i>MbICE1</i> of <i>Malus baccata</i> was investigated in <i>Arabidopsis</i>. According to GFP fluorescence images, MbICE1 was determined to be a nuclear protein. The <i>MbICE1</i> was transferred to <i>Arabidopsis</i>, showing enhanced tolerance to drought and cold stresses. Under drought and cold treatments, the transgenic <i>Arabidopsis</i> had higher chlorophyll content and free proline content than WT plants, but the Malondialdehyde (MDA) content and electrolyte leakage (EL) were lower than those of WT plants. In addition, drought and cold led to a large accumulation of ROS (H₂O₂ and O²⁻) content in <i>Arabidopsis</i>, while overexpression of <i>MbICE1</i> enhanced the antioxidant enzyme activity in <i>Arabidopsis</i> and improved the plant’s resistance to stresses. Moreover, the accumulation of <i>MbICE1</i> promoted the expression of <i>AtCBF1</i>, <i>AtCBF2</i>, <i>AtCBF3</i>, <i>AtCOR15a</i>, <i>AtCOR47</i> and <i>AtKIN1</i> genes in <i>Arabidopsis</i>. These data indicate that <i>MbICE1</i> is a key regulator of drought and cold and can be used as a backup gene for breeding <i>Malus</i> rootstocks.