Quantitative proteomics reveals an enhanced antioxidant potential coupled with sustained energy-driving pathways as key to salt adaptation in Arak plant (Salvadora persica L.)

Arak (Salvadora persica L.) is known as a toothbrush tree for its medicinal benefits for oral health and its antioxidant, analgesic, and anti-inflammatory properties. The plant has a remarkable ability to tolerate abiotic stress, especially drought and high salinity. The molecular mechanisms underlying this tolerance are yet to be determined. In this study, we show that salinity tolerance in the Arak plant is mediated by the ability of its roots to maintain a Na⁺/K⁺ balance when subjected to high salinity. Our proteome analysis of Arak leaves found an accumulation of proteins involved in energy metabolism pathways, indicating that Arak leaves maintain their energy-driving mechanisms under salinity stress conditions. While in roots the proteins involved in ROS scavenging and stress-related pathways were significantly differentially expressed. This suggests that the roots act as a first barrier to alleviating salinity-induced oxidative stress. Our study identifies key proteins and pathways that could have biotechnological importance and could be translated to crop species to improve their abiotic stress tolerance capacities.