Effect of Inoculation with Glomus versiforme on Cadmium Accumulation, Antioxidant Activities and Phytochelatins of Solanum photeinocarpum

Abstract

The plant growth, phosphate acquisition, Cd translocation, phytochelatins (PCs) production and antioxidant parameters [superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione (GSH), ascorbate (ASA) and malonaldehyde (MDA)] were investigated in Cd-hyperaccumulator Solanum photeinocarpum inoculated with Glomus versiforme BGC GD01C (Gv) in Cd-added soils (0, 5, 10, 20, 40 mg Cd kg-1 soil). Mycorrhizal colonization rates were generally high (from 77% to 94%), and hardly affected by Cd. Gv colonization significantly enhanced P acquisition, growth and total Cd uptakes in both shoots and roots of S. photeinocarpum at all Cd levels. Meanwhile, Gv symbiosis significantly increased Cd concentration in the roots, and decreased Cd concentration in the shoots at all Cd levels, which indicates that Gv could promote phytostabilization by enhancing Cd accumulation in the roots to inhibit its translocation to shoots and the “dilution effects” linked to an increase in plant dry matter yield and a reduced Cd partitioning to shoots. Moreover, the improvement of CAT, POD and APX activities in the leaves of mycorrhizal plants infers that Gv symbiosis helped S. photeinocarpum to relieve oxidative damage to biomolecules in Cd-contaminated soil. The evident decline of MDA content in the leaves of mycorrhizal plants indicates that Gv symbiosis evidently improved antioxidant activities, and the enhancement of PCs production in the leaves of mycorrhizal plants suggests that Gv-inoculated plant may be more efficient to relieve Cd phytotoxicity. Therefore, the possible mechanisms of Cd phytotoxicity alleviation by Gv can be concluded as the decline of Cd concentration in the shoots and the improvement of P acquisition, PCs production and activities of CAT, POD, APX in mycorrhizal plants.

Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils

“…Other studies, largely in greenhouses, have typically found that metals decrease AMF colonization and/or diversity (del Val et al 1999a,b; Khan 2001; Chen et al 2005), although Diaz et al (1996) and Tan et al (2015) found no effect of applied Zn, Pb, or Cd solutions on AMF colonization of three host plants, and Vogel-Mikus et al (2006) found that increasing soil Cd and Pb by mixing contaminated and uncontaminated soils in different ratios increased AMF colonization of the hyperaccumulator Thlaspi praecox . Reported effects of AMF colonization on plant metal uptake are similarly inconsistent (e.g.…”

Can arbuscular mycorrhizal fungi reduce Cd uptake and alleviate Cd toxicity of Lonicera japonica grown in Cd-added soils?

“…AMF can stimulate plant growth by increasing nutrient uptake 16 17 , supply a HM isolation belt to protect plant from HM toxicity, and reduce the absorption of HM by plants through secreting organic compounds (e.g., glomalin) in the soil to chelate HM ions 18 19 . Moreover, AMF could increase the activities of antioxidative system under HM stress 20 21 , and some genes with presumptive roles in alleviating oxidative stress were found in AMF 22 . However, the overall mechanisms by which AMF alleviate HM phytotoxicity have still been not completely understood, with controversial outcomes depending on the interactions of specific plant, fungus and HM species.…”

Short-Term Response of Plants Grown under Heavy Metal Toxicity

“…The best results were obtained when mycorrhiza and putrescine were treated together for alleviation of Cd toxicity in sorghum. Mycorrhizal plants along with putrescine displayed lower lipid peroxidation and low hydrogen peroxide production [40,[54][55][56]. It is widely accepted that diminishing levels are one of the mechanisms by which AM protects plants against diverse stresses [57][58][59].…”