The mitochondrial ADP/ATP carrier 1 is associated with changes in leaf tissue organization in Arabidopsis thaliana

The mitochondrial ADP/ATP carrier 1 (AAC1) connects oxidative phosphorylation with cellular metabolism by mediating adenylate exchange across the inner mitochondrial membrane. However, its contribution to leaf structural development remains poorly understood. Here, we performed a preliminary anatomical characterization of Arabidopsis thaliana plants with reduced AAC1 expression. Compared with wild-type plants, genotypes with reduced AAC1 expression showed an apparent reduction in leaf blade thickness, less pronounced mesophyll differentiation, and smaller midrib cross-sectional areas. The parenchymatous region surrounding the vascular bundle also appeared reduced, possibly reflecting changes in cell size, cell number, or both. Despite these differences, all genotypes retained the typical leaf organization of A. thaliana, including amphistomatic leaves, a uniseriate epidermis, differentiated palisade and spongy parenchyma, and clearly distinguishable xylem and phloem tissues. Although quantitative histometric analyses are still ongoing, the consistency of the anatomical patterns among the evaluated genotypes suggests that reduced AAC1 expression may influence leaf morphogenesis, mesophyll organization, and midrib development.