Arbuscular mycorrhizal (AM) fungi inoculation is considered a potential biotechnological tool for an eco-friendly remediation of hazardous contaminants. However, the mechanisms explaining how AM fungi attenuate the phytotoxicity of metal(oid)s, in particular arsenic (As), are still not fully understood. The influence of As on plant growth and the antioxidant system was studied in Leucaena leucocephala plants inoculated with different isolates of AM fungi and exposed to increasing concentrations of As (0, 35, and 75 mg dm⁻³) in a Typic Quartzipsamment soil. The study was conducted under greenhouse conditions using isolates of AM fungi selected from uncontaminated soils (Acaulospora morrowiae, Rhizophagus clarus, Gigaspora albida; and a mixed inoculum derived from combining these isolates, named AMF Mix) as well as a mix of three isolates from an As-contaminated soil (A. morrowiae, R. clarus, and Paraglomus occultum). After 21 weeks, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were determined in the shoots in addition to measuring plant height and mineral contents. In general, AM fungi have shown multiple beneficial effects on L. leucocephala growth. Although the activity of most of the stress-related enzymes increased in plants associated with AM fungi, the percentage increase caused by adding As to the soil was even greater for non-mycorrhizal plants when compared to AM-fungi inoculated ones, which highlights the phytoprotective effect provided by the AM symbiosis. The highest P/As ratio observed in AM-fungi plants, compared to non-mycorrhizal ones, can be considered a good indicator that the AM fungi alter the pattern of As(V) uptake from As-contaminated soil. Our results underline the role of AM fungi in increasing the tolerance of L. leucocephala to As stress and emphasize the potential of the symbiosis L. leucocephala-R. clarus for As-phytostabilization at moderately As-contaminated soils.

Plant establishment, presence of arbuscular mycorrhizal fungi (AMF) and other rhizospheric fungi were studied in mine wastes from Zimapan, Hidalgo state, Mexico, using a holistic approach. Two long-term afforested and three non-afforested mine tailings were included in this research. Fifty-six plant species belonging to 29 families were successfully established on the afforested sites, while unmanaged tailings had only a few native plant species colonizing the surrounding soils. Almost all plant roots collected were associated to AMF in these sites. The genus Glomus was the most abundant AMF species found in their rhizosphere; however, the Acaulospora genus was also observed. Other rhizospheric fungi were identified by 18S rDNA sequencing analysis. Their role in these substrates, i.e. biocontrol, pollutant- and organic matter-degradation, and aides that increase plant metal tolerance is discussed. Our results advance the understanding of fungal diversity in sites polluted with metals and present alternative plants for remediation use.

Fungi are important compartments of microbial communities of mangroves. Their diversity might be influenced by their habitat environment. This study analyzed the distribution and function of fungal communities in the sediments and plant samples from mangrove ecosystem of the Maowei Sea area in Guangxi, China. The results showed that phytopathogenic fungi Cladosporium (17.00%) was mainly observed in the sediments from the protected zone, while endophytic fungi Alternaria (9.22%) and Acremonium (6.09%) were only observed in the sediments from wharf. The fungi in the sediments from village and park were mainly consisted of high-activity endophytes and fungi related to lignin-degrading, respectively. Acaulospora and Aspergillus with higher relative abundance discovered in plant tissues could help plant growth. Cirrenalia (37.66%) and Lignincola (26.73%) with high-activity for lignin-degrading were discovered in decayed leaves. The distribution and function of fungi were highly dependent on the environment settings, thus the fungi can be used as indicators for monitoring the environmental change of mangrove ecosystems.

The objective of this research was to evaluate a soil recovery strategy in soils that were affected by iron mining tailing using herbaceous species inoculated with Acaulospora morrowiae (arbuscular mycorrhizal fungus (AMF)). Tailings were collected on the banks of the Gualaxo do Norte river, one of the places impacted by the Fundão Dam rupture, where tailing layers that were more than one meter were deposited. The experiment was carried out in a greenhouse, using 6 kg pots of non-sterile reject, in a randomized block design in a 4 × 2 factorial scheme, with four cropping systems (Urochloa ruziziensis single crop–RS; and intercropping cultivation: U. ruziziensis with Crotalaria spectabilis–R + C; U. ruziziensis with Guizotia abyssinica–R + G and U. ruziziensis with C. spectabilis and G. abyssinica–R + C + G), with two AMF inoculation conditions (with 200 A. morrowiae spores per pot, and no inoculation), with three replications and 100 days duration. The R + C and R + C + G systems presented the highest shoot dry matter (SDM) yields. Regarding root dry matter production (RDM), a variation of 9.2 g of pot⁻¹ roots was observed between the R + C and R + G systems. Mycorrhizal colonization (MC) was higher in the cultivation system with the three herbaceous species, being the R + C + G system 52% higher than RS system. Spore density did not vary among treatments. Microbial carbon biomass was higher in the RS and R + G treatments when not inoculated. Basal respiration was also higher when not inoculated. Overall, the R + C + G system was more efficient than other systems in the accumulation of elements. The cultivation system with three herbaceous plants proved to be efficient in establishing itself initially in the iron mining tailings, being a viable alternative for the rehabilitation process.