Effects of an Arbuscular Mycorrhizal Fungus on the Growth of and Cadmium Uptake in Maize Grown on Polluted Wasteland, Farmland and Slopeland Soils in a Lead-Zinc Mining Area

Abstract

Arbuscular mycorrhizal fungi (AMF) exist widely in soil polluted by heavy metals and have significant effects on plant growth and cadmium (Cd) uptake. Cd contents differ among wasteland, farmland and slopeland soils in a lead-zinc mining area in Yunnan Province, Southwest China. The effects of AMF on maize growth, root morphology, low-molecular-weight organic acid (LMWOA) concentrations and Cd uptake were investigated via a root-bag experiment. The results show that AMF increased maize growth on Cd-polluted soils, resulting in increases in root length, surface area, volume and branch number, with the effects being stronger in farmland than in wasteland and slopeland soils; increased malic acid and succinic acid secretion 1.3-fold and 1.1-fold, respectively, in roots on farmland soil; enhanced the iron- and manganese-oxidized Cd concentration by 22.6%, and decreased the organic-bound Cd concentration by 12.9% in the maize rhizosphere on farmland soil; and increased Cd uptake 12.5-fold and 1.7-fold in shoots and by 25.7% and 86.6% in roots grown on farmland and slopeland soils, respectively. Moreover, shoot Cd uptake presented significant positive correlations with root surface area and volume and LMWOA concentrations. Thus, these results indicated the possible mechanism that the increased maize Cd uptake induced by AMF was closely related to their effect on root morphology and LMWOA secretion, with the effects varying under different Cd pollution levels.

Arbuscular Mycorrhizal Fungi Reduce Cadmium Leaching from Sand Columns by Reducing Availability and Enhancing Uptake by Maize Roots

“…The strain used in this study was Funneliformis mosseae , which is highly tolerant to Cd and was provided by the Beijing Academy of Agriculture and Forestry’s Institute of Plant Nutrition and Resources (BGCYN05, 1511C0001BGCAM0013) [ 24 ]. Hoagland solution was prepared from modified Hoagland formula, iron salt solution and trace element solution [ 25 ].…”

Physiological and Enzymatic Antioxidant Responses of Solanum tuberosum Leaves to Arbuscular Mycorrhizal Fungal Inoculation under Water Stress

“…Previously, oxalic acid was reported to be present at concentrations between 0.55 and 1.53 mg g −1 in the potato genotypes also used this study [ 18 ], and it was lower than the concentrations reported in the present study. The presence of AMF in Solanum lycopersicum plants has been shown to increase the contents of LMWOAs such as oxalic, succinic, and citric acids [ 53 ], and in corn plants, an increase in the exudation of these compounds due to inoculation has been reported [ 54 ]. For instance, in a study evaluating the effects of the AMF Rhizophagus aggreatus , Claroideoglomus etunicatum , and Funneliformis mosseae on corn plants, 10 LMWOAs were isolated and identified, but the compositions of the exudates varied depending on the growth stage and the fungal strain used as inoculant [ 55 ].…”

Role of Arbuscular Mycorrhizal Fungi in Regulating Growth, Enhancing Productivity, and Potentially Influencing Ecosystems under Abiotic and Biotic Stresses

“…Phytoremediation, using plants to remove toxic metals from the soil, is gaining popularity as a feasible and environmentally friendly method of cleaning polluted land [118,253]. According to reports, AMF has developed strategies that involve immobilizing metallic compounds, precipitating particles of phosphate in the ground, adsorbing chitin within the cell wall made up of fungus, and, ultimately, chelating heavy metals inside the AMF [254]. These strategies could reduce heavy metallic dangers in blended subculture systems and, as a result, from the natural pecking orders [255].…”