Superfamily of Glycolipid Transfer Proteins (GLTPs): Accelerated Cell Death 11-like (ACD11) Enhances Zn Tolerance

Zinc (Zn) is an essential trace element that plays a crucial role in plant growth and development, but excessive Zn can be stressful or even toxic to plants. The GLTP superfamily is critical for lipid metabolism and membrane stability maintenance, yet its function in plant Zn tolerance remains unclear. In this study, zinc stress treatment experiments were performed using transgenic apple calli, apple seedlings, Arabidopsis thaliana, and Solanum lycopersicum. Under Zn treatment, compared with the wild type (WT), the apple seedlings of the MbACD11 transgenic line exhibited significantly higher plant height and fresh weight, with increases of 5.87% and 93.21% respectively. Meanwhile, their MDA level, relative electrical conductivity, and accumulations of H2O2 and O2− were all significantly reduced, with decreases of 20.47%, 35.47%, 31.50%, and 36.78% respectively. Consistently, these data showed the same trend in calli, Arabidopsis thaliana, and tomato. These results demonstrated that the overexpression of MbACD11 significantly enhanced Zn tolerance in transgenic plants, and also verified that the function of this gene may be conserved across different species. In summary, this study establishes a molecular framework and theoretical basis for improving plant tolerance to Zn stress and paves the way for future mechanistic investigations.