Abiotic stress-induced genes may lead to understand the response of plants and adaptability to salinity and drought stresses. Differential display reverse transcriptase – polymerase chain reaction (DDRT-PCR) was used to investigate the differences in gene expression between drought- and salinity-stressed plantlets of Ruta graveolens. Direct and stepwise exposures to drought- or salt-responsive genes were screened in R. graveolens plantlets using the DDRT technique. Gene expression was investigated both in the control and in the salt or drought-stressed plantlets and differential banding patterns with different molecular sizes were observed using the primers OPA-01 (646,770 and 983 pb), OPA-08 (593 and 988 pb), OPA-11 (674 and 831 pb), OPA-17 (638,765 and 1000 pb), and OPA- 15 (645 and 900 pb) indicating the expression of new genes amplified under stress conditions or of genes that already exist. Accordingly, DDRT-PCR seems to be a versatile and sensitive method, capable of detecting transcriptional changes at the mRNA level in plants
