Project description:Prunus mongolica is a relict xerophytic shrub with ecological importance for desert ecosystem stability and vegetation restoration in arid and semi-arid regions. However, the physiological and molecular mechanisms underlying its responses to combined alkali-salt and cadmium stress remain unclear. This study aimed to investigate the regulatory role of exogenous gamma-aminobutyric acid (GABA) in improving stress tolerance in Prunus mongolica under alkali-salt stress, cadmium stress, and their combined stress. Seedlings were subjected to eight treatments, including control, GABA alone, alkali-salt stress, cadmium stress, combined alkali-salt and cadmium stress, and the corresponding GABA-treated stress groups. Germination traits, seedling growth, physiological indices, antioxidant responses, osmotic adjustment, photosynthetic pigments, and transcriptomic profiles were analyzed to evaluate the effects of GABA at multiple biological levels. Alkali-salt, cadmium, and combined alkali-salt and cadmium stress markedly inhibited seed germination and seedling growth, with the combined stress causing the most severe damage. Stress treatments promoted reactive oxygen species accumulation, lipid peroxidation, photosynthetic inhibition, and reductions in water status and root activity. Exogenous GABA alleviated these stress-induced effects by improving germination performance, seedling growth, chlorophyll accumulation, root activity, and relative water content, while reducing oxidative damage. GABA also enhanced osmotic adjustment by increasing proline and soluble sugar contents and strengthened antioxidant defense through the activation of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione reductase. Transcriptome analysis showed that GABA modulated stress-responsive genes associated with MAPK signaling, plant hormone signal transduction, plant-pathogen interaction, peroxisome, glutathione metabolism, photosynthesis, carbon metabolism, and other primary metabolic processes. These results suggest that exogenous GABA enhances stress tolerance in Prunus mongolica by coordinating redox homeostasis, osmotic regulation, stress signaling, photosynthetic recovery, and metabolic reprogramming under single and combined alkali-salt and cadmium stresses.
2026-07-03 | GSE337475 | GEO
