The fungus lewia sp. Alleviates the oxidative stress in f. arundinacea during the endophyte-assisted phytoremediation of hydrocarbons

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are mutagenic and carcinogenic compounds, which accumulate in the environment. Endophyte-assisted phytoremediation is a feasible alternative to reduce the concentration of PAHs in soils more e_ciently than plants or microorganisms individually. Endophytes improve the growth, fitness, and antioxidant system of their hosts, especially under stress conditions. This study aimed to assess the influence of Lewia sp. on the antioxidant defense and hydrocarbon removal by F. arundinacea during 45 days of exposure to a hydrocarbon mixture. Plant growth and lipid peroxidation (LPO), as well as superoxide dismutase (SOD), peroxidase (POD) and glutathione S-transferase (GST) activities were determined in a kinetic assay. The association improved the hydrocarbon removal (7-44 units above the non-associated plant) over a 45-day period, while promoting plant growth (about 2-fold) and controlling oxidative damage, particularly in the roots. The root antioxidant system in F. arundinacea is itself e_ective in counteracting the phytotoxicity of direct contact with hydrocarbons. However, the fungus’s antioxidant system, which involves the coordinated activity of SOD and POD, helps control LPO in the roots. Once the endophytic association is established, it could be e_ectively applied to phytoremediate hydrocarbon-polluted soils during a minimum period of 45 days.