Fuente: PubMed "Tomato process" Planta. 2026 Apr 9;263(5):129. doi: 10.1007/s00425-026-04993-1.ABSTRACTThis study identified the MdDIC2 gene and demonstrated that its overexpression enhanced salt tolerance in apple by mediating citric acid efflux from mitochondria to the cytoplasm. To counteract osmotic water loss caused by salt, plants release citric acid, a tricarboxylic acid (TCA) cycle intermediate whose transmembrane movement is mediated by dicarboxylate carriers (DICs). Although this process has been demonstrated in other plant species, the role of DIC transporters in apple salt tolerance remains unclear. The gene encoding the DIC protein, MdDIC2, was cloned and studied in the current work. Salt stress elevated citric acid levels in apple plants; moreover, exogenous citric acid further enhanced salt tolerance in both apple and Arabidopsis. At the same time, salt stress significantly induced MdDIC2 expression. Arabidopsis and tomato transgenic lines expressing MdDIC2 exhibited enhanced salt stress tolerance, along with reduced accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS) under salt stress. The overexpression of MdDIC2 significantly enhanced salt stress tolerance in apple calli. Moreover, MdDIC2 overexpression enhanced citric acid efflux from mitochondria in apple calli, Arabidopsis and tomato. These results indicate that MdDIC2 enhances apple salt tolerance by mediating citric acid efflux. In conclusion, this study revealed that MdDIC2 plays a pivotal role in plant salt tolerance by mediating citric acid efflux, thus providing a basis for dissecting the underlying molecular mechanisms.PMID:41957204 | DOI:10.1007/s00425-026-04993-1