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As an excellent grafting material, <i>Malus baccata</i> (L.) Borkh is native to Liaoning, Jilin, Heilongjiang and other regions in China, with a strong adverse environmental adaptability. As a typical transcription factor, the NAC gene acts as a regulator in many molecular pathways responding to abiotic stress. However, research of NAC in the <i>Malus baccata</i> has just begun. In the present research, a new NAC transcription factor, <i>MbNAC22</i>, was obtained from the seedlings of <i>Malus baccata</i>, and its function in drought and salt treatments was studied by heterologous expression. The open reading frame of the <i>MbNAC22</i> gene is 768, encoding 255 amino acids (aa). Through confocal microscopy, <i>MbNAC22</i> was found to be located in the nucleus. The heterologous expression of <i>MbNAC22</i> in <i>Arabidopsis</i> showed that it enhanced the viability of <i>Arabidopsis</i> under drought and salt treatments. Under stresses, the chlorophyll content of the plants decreased, but the decline of the overexpressed-<i>MbNAC22 Arabidopsis</i> was relatively low. Through phenotypic observation and determination of stress-related physiological indicators, it was found that compared with WT <i>Arabidopsis</i>, overexpressed-<i>MbNAC22 Arabidopsis</i> had a higher tolerance to stresses. Under stresses, the overexpression of <i>MbNAC22</i> positively regulated ion-transport-related genes (<i>AtNHX1</i> and <i>AtSOS1</i>), the key genes of the ABA pathway (<i>AtNCED3</i> and <i>AtDREB2A</i>), the proline synthesis gene (<i>AtP5CS2</i>) and the drought-induced gene (<i>AtERD11</i>), while the expression of the leaf senescence-associated gene (<i>AtSAG21</i>) and programmed cell death related gene (<i>AtAEP1</i>) was inhibited. Therefore, we speculate that <i>MbNAC22</i> responds positively to drought and salt stresses by regulating the expression of stress-related genes.