Overexpression of cytoplasmic Solanum tuberosum Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene improves PSII efficiency and alleviates salinity stress in Arabidopsis

In this study, transgenic Arabidopsis lines expressing a potato gene (D43), encoding Glyceraldehyde 3-phosphate dehydrogenase, were studied. The D43 plants exhibited improved morphological parameters and accumulation of photosynthetic pigments compared to wild-type (WT) plants under salinity stress conditions. In addition, the D43 transgenic plants showed significantly reduced electrolyte leakage, higher stomatal conductance, lower malondialdehyde (MDA) content, and higher proline content than the WT plants under salinity stress. The gene expression analysis showed that the D43 plants accumulated 1.7-fold, 2.2-fold, and 1.3-fold higher mRNA transcripts of genes encoding the antioxidant enzymes ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT), respectively under salt-stress conditions. Furthermore, they significantly altered the expression of seven major stress-responsive genes, which indicated that overexpression of the potato D43 gene gave salinity stress resistance to Arabidopsis. Chlorophyll-a fluorescence kinetics confirmed the efficient photon absorption, electron transport, and overall PSII efficiency that led to improved photosynthesis in the D43 plants subjected to NaCl-induced salinity stress. Overall, our findings have suggested that potato D43 is a potential candidate gene for developing salinity stress resistance in higher plants.