Effect Of Arbuscular Mycorrhizal Fungi On Accumulation And Resistance Of Antimony In Plants

Today, most of studies have shown a positive impact of arbuscular mycorrhizal fungi (AMF) on their associated plants in resisting heavy metal contaminated soil. Researches on the mechanism of this effect indicated that cell wall of mycorrhizal root or fungal slim may chelate the metal ions, and mycorrhizal fungi mycelia may filter the excessive metals. Some studies also supported that mycorrhiza enhanced tolerance of host plants by improving the P absorption or the antioxidant enzyme activity.Our previous investigations have shown that most plants growing around antimony (Sb) mines have formed mycorrhizal; we speculate that AMF may also play an important role in improving plant resistance to the toxicity stress of antimony. At present, very limited information is so far available about the role of AMF in plant adaptation to heavy Sb contamination, and especially for their effects on plant coexistence under Sb contamination. Using the greenhouse inoculated and non-inoculated control experiment, the present study investigated the influences of inoculation by AMF on growth, Sb uptake, mineral nutrition, antioxidant defense systems and possible interactions of plants growing in a Sb-contaminated soil. Thus the experiment aimed to reveal the significance of AMF symbioses in plant adaptation to Sb contamination and the uptake, detoxification of antimony by plants.(1) In the simulation of antimony contamination conditions, with Sb concentration rising, antimony show the poisoning effect that the mycorrhizal infection rate of two host plant have had been inhibited; the treatment of inoculated AMF significantly contribute to the Sb absorption and accumulation of two host plants; The shoots antimony content of Medicago sativa higher than Bermuda grass, but the root infection rate lower than Bermuda grass under the inoculated treatment.(2) In the simulation of antimony contamination conditions, with Sb concentration rising, antimony show the poisoning effect that the biomass and phosphorus content of two host plant have had been inhibited; the treatment of inoculated AMF significantly contribute to the biomass and phosphorus content of two host plants; The resualts indicating that under Sb stress, AMF can improve the nutritional status of the host plant, and promote the biomass of plants, enhance the roots length;(3) In the simulation of antimony contamination conditions, with Sb concentration rising, antimony show the poisoning effect that the antioxidant enzyme activity increased; and the AMF treatment reduced the MDA, soluble protein content and antioxidant enzyme activity of two host plant;The possible reasons that the AMF reduced the antimony poison in plants, that reduced the chemical stimulation effect of antioxidant enzymes system, the specific impact of the mechanism needs further study.