Gamma-aminobutyric acid (GABA) and salinity impacts antioxidative response and expression of stress-related genes in strawberry cv. Aromas

Salinity is one of the most crucial abiotic stresses which is the consequence of increase in the concentration of NaCl ions influencing plant’s growth, development, and yield. Gamma-aminobutyric acid (GABA) is a non-protein amino acid involved in various metabolic processes that accumulates in many plant species during stress conditions. The present study was aimed to evaluate the effect of GABA (0 and 25 mM) and salinity (3 and 5 dS m −1 ) on physiological characteristics and expression pattern of some salinity-related genes in strawberry cv. Aromas under soilless culture condition at 12, 24, and 36 h after treatments’ initiation. Based on the results, salinity increased the content of H 2 O 2 , MDA, and proline, while it decreased the percentage of MSI and the activity of SOD and POD antioxidant enzymes. In contrast, the implementation of GABA not only decreased H 2 O 2 and MDA content and maintained MSI percentage, but it also improved the activity of antioxidant enzymes and the transcription level of DREB , cAPX , MnSOD , and GST genes. Under non-stress conditions, GABA acted as a mild stressor by imposing effects similar to abiotic stress which could help plants adapt under the adverse environmental conditions. We concluded that strawberry plants had a better response to salinity by enhancing both enzymatic and non-enzymatic antioxidant physiological protection mechanisms and also by increasing the transcription of salinity-related genes upon GABA application.