Arsenic hyperaccumulator Pteris vittata shows reduced biomass in soils with high arsenic and low nutrient availability, leading to increased arsenic leaching from soil

• Published in: The Science of the total environment Vol. 818; p. 151803
• Main Authors: Matzen, S.L., Lobo, G.P., Fakra, S.C., Kakouridis, A., Nico, P.S., Pallud, C.E.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.04.2022
• Subjects: Arsenic - analysis; Arsenic speciation; Biodegradation, Environmental; Biomass; Nutrients; Phytoextraction; Pteris - metabolism; Rhizosphere; Soil; Soil Pollutants - analysis; Soil texture; Unsaturated soil columns; X-ray absorption spectroscopy; X-ray fluorescence; Arsenic speciation; Rhizosphere; X-ray fluorescence; Unsaturated soil columns; Soil texture; X-ray absorption spectroscopy; Phytoextraction
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.151803

Plant-soil interactions affect arsenic and nutrient availability in arsenic-contaminated soils, with implications for arsenic uptake and tolerance in plants, and leaching from soil. In 22-week column experiments, we grew the arsenic hyperaccumulating fern Pteris vittata in a coarse- and a medium-textured soil to determine the effects of phosphorus fertilization and mycorrhizal fungi inoculation on P. vittata arsenic uptake and arsenic leaching. We investigated soil arsenic speciation using synchrotron-based spectromicroscopy. Greater soil arsenic availability and lower nutrient content in the coarse-textured soil were associated with greater fern arsenic uptake, lower biomass (apparently a metabolic cost of tolerance), and arsenic leaching from soil, due to lower transpiration. P. vittata hyperaccumulated arsenic from coarse- but not medium-textured soil. Mass of plant-accumulated arsenic was 1.2 to 2.4 times greater, but aboveground biomass was 74% smaller, in ferns growing in coarse-textured soil. In the presence of ferns, mean arsenic loss by leaching was 195% greater from coarse- compared to the medium-textured soil, and lower across both soils compared to the absence of ferns. In the medium-textured soil arsenic concentrations in leachate were higher in the presence of ferns. Fern arsenic uptake was always greater than loss by leaching. Most arsenic (>66%) accumulated in P. vittata appeared of rhizosphere origin. In the medium-textured soil with more clay and higher nutrient content, successful iron scavenging increased arsenic release from soil for leaching, but transpiration curtailed leaching. [Display omitted] •Soil characteristics, fern growth, and transpiration affect soil arsenic leaching.•Arsenic is more phytoavailable and leachable in soil with lower clay content.•Stress of phytoavailable arsenic tolerance and poor nutrition limit biomass.•Healthy fern growth enhances arsenic availability for uptake and leaching.•Transpiration limits arsenic leaching.