Xyloglucan represents the primary hemicellulose component in higher plant cell walls, providing mechanical support. The XTH gene family encodes xyloglucan endotransferase/hydrolase, a crucial enzyme in cell wall remodeling. Studies examining XTH family-related genes in apples remain limited. This study investigated the MdXTH30 gene, isolated from apple (Malus×domestica), which demonstrated responsiveness to abscisic acid, NaCl, and polyethylene glycol (PEG) 6000, with cytoplasmic localization confirmed through subcellular mapping. To elucidate the role of MdXTH30 in stress response, transgenic MdXTH30 apple calli were generated and the gene was heterologously expressed in Arabidopsis via Agrobacterium-mediated transformation. The findings revealed that MdXTH30 enhanced resistance to drought, salt stress, and pathogens through regulation of relevant genes in both apple calli and Arabidopsis. These results identify potentially significant candidate genes for improving biotic and abiotic stress resistance at the cell wall level.