HSP70 AND THETA SUBUNIT OF T COMPLEX PROTEIN , A RESPONSE TO SALT STRESS IN THE HALOPHYTE SESUVIUM PORTULACASTRUM

The proteomic analysis was performed to explore the salt responsive proteins in S. portulacastrum a salt marsh euhalophyte. Protein profile showed profound differences in the expression pattern of salt treated plant. The total protein content was significantly high in leaf than in shoot and root. 2D electrophoresis revealed that 7 proteins were down regulated, 6 proteins were up-regulated and 46 proteins were newly expressed in S.portulacastrum leaves. Two spots from newly expressed proteins were randomly selected and characterized by MALDI-TOF/MS analysis. Protein mass fingerprinting annotation showed different peptide intensities and subsequent sequence homology search using MASCOT software categorized those proteins as Hsp70 and theta subunit of T complex protein with pI/kDa, 5.2/70kDa and 4.9/53kDa respectively. Hsp70 has been proposed as biomarker for stress produced by NaCl which emphasize its role in protecting plants against stress, whereas theta subunit of T complex protein seems to have role during protein folding expressed during abiotic stress, which yet to be characterized. The resulting findings addressed the significance of stress related proteins on the survival of plants in extreme conditions and it can be complemented with large scale studies on functional and molecular interaction of proteins expressed during saline stress.