By-products of the petroleum industry contaminate the environment, hence decreasing the soil fertility. However, in some contaminated areas, plants such as Cayratia trifolia continue to survive despite the harsh environment. Therefore in this study we aim to investigate the survival of C. trifolia at a petroleum refinery, PETRONAS Penapisan Melaka Sdn. Bhd (PPMSB). The main objective of this study was to identify and characterize candidate gene involved in the stress response. Differential display approach was performed on C. trifolia grown on soil and sludge, to identify up-regulated and down-regulated partial cDNAs. Out of 23 cDNAs checked, 18 genes were up-regulated genes while five were down-regulated. A partial gene (244 bp) represented by DEG7 fragment has a high similarity to the translocon. Blast2GO analyses was performed and showed DEG7 as a gene responsible for stress responses. A fragment of 1371 bp named as the CtSRG1 gene was succesfully amplified using the combination of RACE-PCR and degenerate PCR amplification. BlastN and BlastX analyses indicated that the CtSRG1 gene had higher similarity to translocon. CtSRG1 protein consists of Rieske and SRPBCC ligand-binding domains. The expression profile of CtSRG1 gene using qRT-PCR showed up-regulated expression when treated with Pb, NaCl and diesel but down-regulated with wounding treatment.