Agronomy (Apr 2020)
<i>Poaceae</i> with PGPR Bacteria and Arbuscular Mycorrhizae Partnerships as a Model System for Plant Microbiome Manipulation for Phytoremediation of Petroleum Hydrocarbons Contaminated Agricultural Soils
Abstract
Total petroleum hydrocarbons (TPHs) are a persistent environmental organic contaminant. The possibility of obtaining synergistic effects between plants and microorganisms has further increased the possibility of alternative techniques for bioremediation. Oloptum miliaceum (L.) Röser & H.R. Hamasha and Pennisetum setaceum (Forssk.) Chiov. are, undoubtedly, good model plants for phytoremediation because they have large roots, leaf biomass, and a fast and effective renewal capacity, also, they have a great capacity to host endophytes in their roots. Gas chromatography-mass spectrometry (GC-MS) based on carbon fraction number was a basic technique used to determine the hydrocarbon degradation, and microorganism’s population was identified by high-throughput sequencing of 16s rRNA. The microbial consortium used allows the plant to increase overall biomass, adapt more in terms of redox biology (Superoxide dismutase SOD, catalase CAT, ascorbate peroxidase APX, guaiacol peroxidase GPX), and stress markers (Glutathione S-transferase GST, Phenylalanine Ammonia Lyase PAL, Proline content, and lipid peroxidation MDA). In addition, the photosynthetic efficiency and the soil dehydrogenase activity were monitored. After 240 days, the percentage of TPHs removed in Group 2 was 94%, whereas in Group 1, it was 78% in Oloptum miliaceum and Pennisetum setaceum. The removal of aliphatic hydrocarbons (C13–C36) was observed in Oloptum miliaceum and Pennisetum setaceum inoculated with the consortium of indigenous bacteria selected from rhizosphere soil and mycorrhizae strains. Our data demonstrate that, the Poaceae, in relation to its great ecological and vegetative potential, could be a great candidate for extensive remediation of soils contaminated by TPHs.
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