Proteomics analysis of salt-induced leaf proteins in two rice germplasms with different salt sensitivity

Abstract

This study was conducted to investigate salt-stress-related physiological responses and proteomics changes in the leaves of two rice (Oryza sativa L.) cultivars. Shoot growth and water content of rice leaves were more severely reduced in Dalseongaengmi-44 than in Dongjin under salt stress. The salt-sensitive Dalseongaengmi-44 exhibited a greater increase in sodium ion accumulation in its leaves than the salt tolerant Dongjin. Comparative analysis of the rice leaf proteins using two-dimensional gel electrophoresis (2-DGE) revealed that a total of 23 proteins were up-regulated under salt stress. Based on matrix-assisted laser desorption ionization-time of flight mass spectrometry and/or electrospray ionization-tandem mass spectrometry analyses, the 23 protein spots were found to represent 16 different proteins. Ten of the identified proteins were previously reported to be salt-responsive proteins, while six, class III peroxidase 29 precursor, beta-1,3-glucanase precursor, OSJNBa0086A10.7 (putative transcription factor), putative chaperon 21 precursor, Rubisco activase small isoform precursor and drought-induced S-like ribonuclease, were novel salt-induced proteins. Under salt stress, fragmentation was increased in several proteins containing the Rubisco large chain. The results of these physiological and proteomics analyses provide useful information that can lead to a better understanding of the molecular basis of salt-stress responses in rice.