Dopamine regulates nitric oxide biosynthesis, optimizes carbon utilization, and maintains potassium retention to support wheat productivity under salt stress

Dopamine, a ubiquitously known catecholamine neurotransmitter in animals, has recently gained prominence for its role as a signaling molecule regulating plant physiological and metabolic activities. However, its potential to mitigate environmental stressors, particularly salt stress, through nitric oxide (NO)-mediated regulation of physiological changes remains largely unexplored in cereal crops such as wheat (Triticum aestivum). The present study investigates the role of dopamine seed priming in enhancing wheat salt tolerance by modulating NO biosynthesis, redox metabolism and ionic balance to support growth and yield. Dopamine priming (100 μM for 16 h) significantly reduced oxidative stress by enhancing both enzymatic as well as non-enzymatic antioxidants by mediating NO biosynthesis and NO synthase (NOS) activity in wheat variety PBW752. Further, the utilization of NO scavenger substantiated dopamine-mediated salt stress alleviation was dependent on the endogenous NO formation. Dopamine induced-photosynthetic regulation and carbon (C)-assimilation were evident from increased total chlorophyll content, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) activity and accumulation of carbohydrates resulting in greater biomass accumulation. Collectively, these findings reveal that dopamine-mediated NO biosynthesis intricately coordinates redox regulation, C utilization and potassium (K⁺) retention, which was associated with improved stomatal regulation to alleviate salt-induced growth and yield disruptions. This study identifies dopamine seed priming as a promising and sustainable strategy to enhance salt tolerance and maintain wheat productivity in salt-stressed environments.