Plant tolerance to mercury in a contaminated soil is enhanced by the combined effects of humic matter addition and inoculation with arbuscular mycorrhizal fungi

• Published in: Environmental science and pollution research international 2016-06, Vol.23 (11), p.11312-11322
• Main Authors: Cozzolino, V., De Martino, A., Nebbioso, A., Di Meo, V., Salluzzo, A., Piccolo, A.
• Format: Article
• Language: English
• Subjects: Acids; Agriculture; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bioaccumulation; Bioavailability; Biomass; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fungi; Glomeromycota - growth & development; Heavy metals; Humic acids; Humic Substances - analysis; Humic Substances - microbiology; Lactuca - growth & development; Lactuca - metabolism; Lactuca - microbiology; Lactuca sativa; Lettuce; Mercury; Mercury - analysis; Mercury - metabolism; Mercury - toxicity; Mycorrhizae - growth & development; Plant biomass; Plant growth; Plant Roots - growth & development; Plant Roots - metabolism; Plant Roots - microbiology; Research Article; Rhizophagus; Sandy soils; Soil - chemistry; Soil contamination; Soil Microbiology; Soil Pollutants - analysis; Soil Pollutants - metabolism; Soil Pollutants - toxicity; Soil treatment; Studies; Synergistic effect; Toxicity; Translocation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-6337-6

In a greenhouse pot experiment, lettuce plants ( Lactuca sativa L.) were grown in a Hg-contaminated sandy soil with and without inoculation with arbuscular mycorrhizal fungi (AMF) (a commercial inoculum containing infective propagules of Rhizophagus irregularis and Funneliformis mosseae ) amended with different rates of a humic acid (0, 1, and 2 g kg −1 of soil), with the objective of verifying the synergistic effects of the two soil treatments on the Hg tolerance of lettuce plants. Our results indicated that the plant biomass was significantly increased by the combined effect of AMF and humic acid treatments. Addition of humic matter to soil boosted the AMF effect on improving the nutritional plant status, enhancing the pigment content in plant leaves, and inhibiting both Hg uptake and Hg translocation from the roots to the shoots. This was attributed not only to the Hg immobilization by stable complexes with HA and with extraradical mycorrhizal mycelium in soil and root surfaces but also to an improved mineral nutrition promoted by AMF. This work indicates that the combined use of AMF and humic acids may become a useful practice in Hg-contaminated soils to reduce Hg toxicity to crops.