Optimizing copper phytoremediation and mung bean (Vigna radiata L.) yield through Sinorhizobium meliloti and Piriformospora indica inoculation

Heavy metal contamination in agricultural soil poses significant threats to ecosystem sustainability and human health. An outdoor box experiment was conducted as factorial abased on randomized complete block design, with three replications, during the 2017 cropping season to evaluate the effects of biofertilizers on Vigna radiata L. growth and yield under different Cu concentrations. The first factor was fertilizer treatment including plant growth-promoting bacterium Sinorhizobium meliloti (PGP), arbuscular mycorrhizal-like fungus Piriformospora indica (AM), and chemical fertilizer (CF) and the second factor was Cu concentrations consisted of 0, 50, 100, and 200 mg _Cu /kg _soil . The greatest plant height and LAI were observed at 0 and 50 mg _Cu /kg _soil , particularly in CF and AM treatments. The highest Cu concentrations in shoot and grain were observed in CF and control treatments, while Cu concentrations in the roots were higher in biofertilizer treatments. In all Cu concentrations, the shoot bioconcentration factors (BCF) in CF and control treatments were higher than those in PGP and AM treatments. The root BCF was improved with the use of PGP and AM treatments, compared to the control. Except for CF, the TF ​​in other treatments were ˂ 1 and the highest translocation factor (TF) was obtained in 200 mg _Cu /kg _soil (0.842) and CF (1.050) treatment. Generally, applying AM under Cu contamination showed a great potential for improving mung bean yield, reducing Cu availability and minimizing plant uptake.