title: Potential of different AM fungi (native from As-contaminated and uncontaminated soils) for supporting Leucaena leucocephala growth in As-contaminated soil.
abstract: 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.
authors.affiliation: School of Civil Engineering, Architecture and Urban Design - FEC, Sanitation and Environment Dept., State University of Campinas - UNICAMP, PO Box 6021, 13083-889, Campinas, SP, Brazil; Department of Soil Science, Federal University of Lavras (UFLA), PO Box 3037, 37200-000, Lavras, MG, Brazil. Electronic address: jerusasch@gmail.com.
authors.forename: Jerusa
authors.initials: J
authors.lastname: Schneider
authors.affiliation: Deputy Vice-Chancellor's Office (Research and Innovation), University of Southern Queensland, West Street, Toowoomba, 4350, QLD, Australia; Faculty of Health, Engineering and Sciences, University of Southern Queensland, West Street, Toowoomba, 4350, QLD, Australia; KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-10044, Stockholm, Sweden.
authors.forename: Jochen
authors.initials: J
authors.lastname: Bundschuh
authors.affiliation: Department of Soil Science, Federal University of Lavras (UFLA), PO Box 3037, 37200-000, Lavras, MG, Brazil.
authors.forename: Wesley de Melo
authors.initials: WM
authors.lastname: Rangel
authors.affiliation: Department of Soil Science, Federal University of Lavras (UFLA), PO Box 3037, 37200-000, Lavras, MG, Brazil. Electronic address: guilherm@dcs.ufla.br.
authors.forename: Luiz Roberto Guimarães
authors.initials: LRG
authors.lastname: Guilherme
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000633:toxicity; D007887:Fabaceae / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development* / Q000382:microbiology*; D055137:Glomeromycota / Q000378:metabolism*; D038821:Mycorrhizae / Q000378:metabolism*; D018520:Plant Shoots / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity; D013559:Symbiosis
chemical_list: D012987:Soil; D012989:Soil Pollutants; D001151:Arsenic
keywords: Antioxidant enzymes; Arsenic contamination; Mycorrhizas; P/As plant content ratio; Phytoremediation