a proteomic approach to analyze saltresponsive proteins in rice leaf sheath to examine the response of rice to salt stress changes in protein expression were analyzed using a proteomic approach to investigate dose and timedependent responses rice seedlings were exposed to 50 100 and 150 mm nacl for 6 to 48 h proteins were extracted from leaf sheath and separated by twodimensional polyacrylamide gel electrophoresis eight proteins showed 1 to 3fold upregulation in leaf sheath in response to 50 mm nacl for 24 h among these three proteins were unidentified lsy081 lsy262 and lsy363 while five proteins were identified as fructose bisphosphate aldolases photosystem ii psii oxygen evolving complex protein oxygen evolving enhancer protein 2 oee2 and superoxide dismutase sod the maximum expression levels of seven proteins were at 24 h their expression declined after 48 h of 50 mm nacl treatment in contrast sod maintained its elevated expression throughout these conditions the increased expression of proteins seen in the 50 mm nacl treatment group was less pronounced in the groups receiving 100 or 150 mm nacl for 24 h the expression of sod was a common response to cold drought salt and abscisic acid aba stresses while the expression of lsy081 lsy363 and oee2 was enhanced by salt and aba stresses lsy262 was expressed in leaf sheath and root while fructose bisphosphate aldolases psii oxygen evolving complex protein and oee2 were expressed in leaf sheath and leaf blade lsy363 was expressed in leaf sheath but was below the level of detection in leaf blade and root these results indicate that specific proteins expressed in specific regions of rice show a coordinated response to salt stress