Taurine priming improves redox balance, osmotic adjustment, and nutrient acquisition to lessen phytotoxic effects of neutral and alkaline salts on pea (Pisum sativum L.).

Abstract

Taurine (TAR) intricately mediates a plethora of physiological processes. This investigation aimed to elucidate the impact of TAR (50, 100, 150, and 200 mg L^-1) seed priming on redox homeostasis, glutathione metabolism, photosynthetic efficiency, osmotic adjustment and nutrient acquisition in pea plants subjected to 100 mm salinity of neutral (NaCl and Na₂SO₄) and alkaline (Na₂CO₃) salts. Salinity diminished growth, chlorophyll, and photosynthetic efficiency alongside a concurrent rise in reactive oxygen species (ROS), lipid peroxidation, and relative membrane permeability. Seed priming with 150 mg L^-1 TAR efficiently enhanced growth by reducing oxidative damage to plants under salinity. Taurine enhanced leaf relative water content through osmotic adjustment facilitated by the induced accumulation of proline, glycine betaine, soluble sugars, and total free amino acids. Taurine increased the levels of antioxidant compounds and the activities of enzymes, which assisted in the detoxification of ROS and methylglyoxal. Taurine maintained chlorophyll integrity and enhanced photosynthetic efficiency by alleviating oxidative stress. Taurine diminished Na content, which improved the acquisition of essential nutrients under the salinity of neutral and alkaline salts. The results suggest that TAR has a potential role in maintaining ion homeostasis, crucial for enhancing pea tolerance to salt stress.