Funneliformis mosseae Enhances Root Development and Pb Phytostabilization in Robinia pseudoacacia in Pb-Contaminated Soil

Abstract

It is possible that arbuscular mycorrhizal fungi play a pivotal role in root development and Pb phytostabilization in plants grown in Pb-contaminated soil. In this study, a pot experiment was conducted over 4 months to evaluate the effects of <i>Funneliformis mosseae</i> strain BGCXJ01A on root characteristics of black locust (<i>Robinia pseudoacacia</i> L.) seedlings in Pb-contaminated soil. Four Pb treatments (0, 90, 900, and 3,000 mg kg^-1) were applied to soil in the presence and absence of <i>F. mosseae</i>. Inoculation with <i>F. mosseae</i> prominently improved root length, surface area, volume, and tip number in the plants across all Pb treatments. The <i>F. mosseae</i> inoculation also increased root diameter and fork number, especially under high Pb treatments. The presence of <i>F. mosseae</i> significantly increased the root activity and root tolerance index. However, there was little difference in specific root length between inoculated and non-inoculated plants. The biomass of roots, stems, and leaves all increased following inoculation with <i>F. mosseae</i>. Inoculated plants had greater accumulation and translocation capacities for Pb in the roots and stems, but lower capacities were found in the leaves when compared with those in non-inoculated plants. These results highlight that <i>F. mosseae</i> can alleviate the toxic effects of Pb on root development and can immobilize Pb in the roots and stems of <i>R</i>. <i>pseudoacacia</i> grown in Pb-contaminated soil. This study provides a model system for phytoremediation of Pb-contaminated soil <i>via</i> reciprocal symbiosis between arbuscular mycorrhizal fungi and woody legumes.