Identification of Salt-induced Changes in Leaf and Root Proteomes of the Wild Tomato, Solanum chilense

Abstract

This article reports salt-induced changes in leaf and root proteomes after wild tomato (Solanum chilense) plants were treated with 200 mm NaCl. In leaf tissues, a total of 176 protein spots showed significant changes (P < 0.05), of which 104 spots were induced and 72 spots suppressed. Salt-induced proteins are associated with the following pathways: photosynthesis, carbohydrate metabolism, glyoxylate shunt, glycine cleavage system, branched-chain amino acid biosynthesis, protein folding, defense and cellular protection, signal transduction, ion transport, and antioxidant activities. Suppressed proteins belong to the following categories: oxidative phosphorylation pathway, photorespiration and protein translational machinery, oxidative stress, and ATPases. In root tissues, 106 protein spots changed significantly (P < 0.05) after the salt treatment, 63 spots were induced, and 43 suppressed by salt treatment. Salt-induced proteins are associated with the following functional pathways: regeneration of S-adenosyl methionine, protein folding, selective ion transport, antioxidants and defense mechanism, signal transduction and gene expression regulation, and branched-chain amino acid synthesis. Salt-suppressed proteins are receptor kinase proteins, peroxidases and germin-like proteins, malate dehydrogenase, and glycine dehydrogenase. In this study, different members of proteins were identified from leaf and root tissues after plants were subjected to salt treatment. These proteins represent tissue-specific changes in salt-induced proteomes. When protein expression was compared in the context of metabolic pathways, the branched-chain amino acid biosynthesis, glucose catabolism toward reducing cellular glucose level, and the antioxidant, detoxification, and selective ion uptake and transport were induced in both root and leaf tissues. These changes appear to be associated with salt tolerance in the whole plant.