Effects of soil petroleum contamination on some physiological and molecular properties of plant

Phytoremediation efficiency -a cost effective and environmentally sound technology to clean up contaminated soil - is reduced considering abiotic stresses. The research objective was to determine the effects of aged petroleum contaminated soil (10% W/W: Total petroleum Hydrocarbons) on two grasses specious (wild oat and barley) during the phytoremediation process. In addition the effects of petroleum degrading rhizobacteria inoculation were evaluated on plant growth promotion and decreasing toxicity of petroleum hydrocarbons. Results demonstrated that petroleum contaminated soil reduced growth, photosynthetic pigments and increased hydrogen peroxide (H2O2), MDA (malondialdehyde), enzymatic antioxidants (catalase and peroxidase) and NCDE and COR2 gene transcripts that indicate oxidative stress happened because of petroleum pollution similar to other common abiotic stress. a/b chlorophyll ratio enhancement and more decrease in shoot dry weight in wild oat showed barley was more tolerate to petroleum pollution. Bacterial inoculation reduced petroleum contamination toxicity and improved plant growth especially in wild oat.