The root is the primary site for sensing salt signals in plants. In recent years, high-throughput proteomic analyses have identified proteins that are differentially expressed under salt treatment in the roots of various plants, including rice (Oryza sativa), Arabidopsis thaliana, soybean (Glycine max), barley (Hordeum vulgare), wheat (Triticum aestivum), and Bruguiera gymnorhiza. These studies have characterized the dynamic changes in the root proteome under salt treatment. This paper gives an overview of the mechanisms of salt adaptation in the root, as determined from recent research on the salt-responsive proteome. These intricate mechanisms consist of multiple biological processes, including (i) perception and transmission of the salt signal by signal transduction pathways, for example, the Ca²⁺ signaling transduction pathway, which includes G proteins, small GTPases, and several kinds of Ca²⁺-binding proteins; (ii) ion uptake/exclusion and compartmentalization via the actions of membrane proteins such as the vacuolar-type H⁺-ATPase-the dominant H⁺ pump at the endomembrane of most plant cells; (iii) detoxification of reactive oxygen species by antioxidant enzymes (e.g., superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase); (iv) alterations in the expressions of key enzymes involved in carbohydrate and energy metabolism (e.g., enzymes in the tricarboxylic acid cycle and glycolysis pathway); (v) remodeling of the cytoskeleton (e.g., actin and tubulin) to maintain cell structure and function; (vi) diverse protein expression and interaction patterns regulated at the transcriptional, translational, and post translational levels; and (vii) maintenance of cellular homeostasis via coordination between primary and secondary metabolism, for example, the assimilation of ammonium.