A PROTEOMIC APPROACH TO IDENTIFY SALT-RESPONSIVE PROTEINS IN RYE

Abstract

Salinity stress negatively impacts agricultural yield throughout the world affecting production whether it is for subsistence or economic gain. Despite their great degree of stress tolerance, minor crops have received little attention regarding their response against salinity compared to model plants and major crops. Rye, an economically important minor grain crop, is relatively tolerant to abiotic stresses and grown in marginal lands. Proteome study based on two dimensional gel electrophoresis and subsequent mass spectrometric identification was performed in order to analyze the salt-stress response of rye. Overall changes in the protein complement of leaves after four days exposure to 200 mM NaCl were studied. Seventeen reproducibly resolved, differentially expressed protein spots were identified by MALDI-TOF MS (mass spectrometry). Among them, ten proteins were up-regulated, and seven proteins were down-regulated. Majority of the differentially expressed proteins belonged to the functional category of antioxidant metabolism and photosyntheis. Increased expression of reactive oxygen species-scavenging enzymes eg, catalase, cytosolic, monodehydroascorbate reductase and 2- cys-peroxiredoxin may have important role in salinity-induced ROS metabolism. This is the first proteomic description of salt stress response in rye and the identification of such differentially expressed proteins would provide deeper insight pertaining to the stress physiology of this important crop plant.