Phytoremediation effect of Medicago sativa colonized by Piriformospora indica in the phenanthrene and cadmium co-contaminated soil

Abstract

Background: The coexistence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals has deleterious effects on environmental quality. Few reports have studied the mechanisms of plant inoculation with Piriformospora indica to remediate PAH-metal co-contaminated soil by analyzing the chemical speciation of the contaminants. This study investigated the influence of the inoculation of Medicago sativa with P. indica to remediate soil co-contaminated with phenanthrene (a kind of PAH) and cadmium (a heavy metal) by analyzing plant growth, physiological parameters and chemical speciation in rhizosphere and nonrhizosphere soils. Results: The presence of P. indica significantly increased plant tolerance, chlorophyll a, chlorophyll b, maximum quantum efficiency of PSII photochemistry and electron transport rate values in phenanthrene-and/or cadmiumcontaminated soil. P. indica inoculation in M. sativa roots increased fluorescein diacetate activities in soils contaminated with phenanthrene, cadmium or both, especially in the nonrhizosphere. The presence of phenanthrene prevented the inoculated plant from accumulating cadmium to some extent, whereas the presence of cadmium did not prevent the degradation of phenanthrene in either the rhizosphere or the nonrhizosphere after P. indica colonization. Although the low bioavailability of cadmium in the rhizosphere restricted its transportation into the stem, P. indica colonization in plants effectively increased cadmium accumulation in roots in soil co-contaminated with cadmium and phenanthrene. Conclusions: In conclusion, this work provides a theoretical basis for the use of P. indica combined with M. sativa for the remediation of PAH-metal co-contaminated soil.

Stress Response and Phytoextraction Potential of Two Noccaea caerulescens Populations in Multicontaminated Soil

“…These results are in full agreement with previous research which showed that PHE and pyrene (PYR) induced negative effects on the phytoextraction of Cd from Cd-spiked soil by the hyperaccumulator Sedum alfredii (Wang et al, 2012). Similarly, it has been reported that Cd accumulation in stems of Medicago sativa was reduced after soil contamination with PHE, which was probably caused by the accumulation of organic pollutants in roots, which hindered Cd transport from roots to aboveground parts (Li et al 2020). Thus, metals uptake capacity may be reduced due to the increased in pH.…”

Effect of Drought Stress, Soil Salinity, P. indica, and MWCNs on Biodegradation of Diesel Oil in the Pb- and Cd-Polluted Soil Under Cultivation of Triticale Plant

“…Regardless of plants growing in salinity or drought stress, our results have shown that the interaction effects of using MWCNs and inoculation of plants with P. indica on decreasing the plant Pb and Cd concentration were positive and enhanced the plant growth in heavy metals-polluted soils [43] and consequently can improve the biodegradation of petroleum hydrocarbon in the soil [44]. However, abiotic stress, such as salinity or drought stress, negatively affects plant growth and physiology.…”

Biopriming of Durum Wheat Seeds with Endophytic Diazotrophic Bacteria Enhances Tolerance to Fusarium Head Blight and Salinity

“…Unfortunately, the agricultural soils underwent the rapid degradation and depletion of nitrogenous matter responsible for plant growth following excessive use by field crops. This threat was overcome by different techniques such as intercropping [ 10 ], the use of PGPB, and natural phytoremediation [ 92 ]. In fact, the result of total nitrogen content in non-bioprimed and bioprimed salt-treated plants and untreated plants clearly showed that the bacterial treatment before germination significantly improved the plant’s capacity to assimilate nitrogen from the soil under salt stress.…”