Effects of Pisolithus tinctorius and Cenococcum geophilum inoculation on pine in copper-contaminated soil to enhance phytoremediation

Abstract

We used Pisolithus tinctorius and Cenococcum geophilum to determine the copper (Cu) resistance of ectomycorrhizal (ECM) fungi and their potential for improving phytoremediation of Cu-contaminated soil by Chinese red pine (Pinus tabulaeformis). The results showed that nutrient accumulation in C. geophilum mycelium was significantly lower under higher Cu concentrations in the soil, which was not observed in P. tinctorius. Meanwhile, P. tinctorius exhibited greater Cu tolerance than C. geophilum. Inoculation with ECM fungi significantly improved the growth of pine shoots planted in polluted soil in pot experiments (p < 0.01). The total accumulated Cu in pine seedlings planted in Cu-contaminated soil increased by 72.8% and 113.3% when inoculated with P. tinctorius and C. geophilum, respectively, indicating that ECM fungi may help their host to phytoextract heavy metals. Furthermore, the majority of the total absorbed metals remained in the roots, confirming the ability of ECM fungi to promote heavy metal phytostabilization. There were no differences between the effects of the two fungi in helping the host stabilize and absorb Cu, even though they have different Cu tolerances. Inoculation with ECM fungi can benefit plant establishment in polluted environments and assist plants with phytoremediating heavy-metal-contaminated soils.

Ectomycorrhizal Fungal Communities and Their Functional Traits Mediate Plant–Soil Interactions in Trace Element Contaminated Soils

“…In relation to this, ectomycorrhizal (ECM) fungi may provide protection against metal toxicity through avoidance (i.e., extracellular precipitation, biosorption to cell walls, reduced uptake) and sequestration (i.e., intracellular chelation, compartmentation into fungi vacuoles) ( Hartley et al, 1997 ; Jentschke and Godbold, 2000 ; Bellion et al, 2006 ). Therefore, phytoremediation of TE polluted soils can be facilitated by ECM fungi as they adapt to TE stress promoting the host growth ( Wen et al, 2017 ).…”

Accumulation and Translocation of Phosphorus, Calcium, Magnesium, and Aluminum in Pinus massoniana Lamb. Seedlings Inoculated with Laccaria bicolor Growing in an Acidic Yellow Soil

“…Vaario et al [52] found that mushrooms of Tricholoma matsutake, and ECM fungus, were enriched in Al. Pisolithus tinctorius increased Cu accumulation in Pinus tabulaeformis and the majority of the Cu remained in the roots [53]. These results indicated that ECM fungi might limit Al 3+ movement toward the inner root tissues and then inhibit Al 3+ translocation to the shoot.…”

The transfer of trace metals in the soil-plant-arthropod system

“…They play a key role in the mobilisation and uptake of organic and inorganic N and P providing access to nutrient sources not directly available to plants (Tibbett and Sanders, 2002;Cairney and Meharg, 2003), and are also known to mobilise trace metals by dissolving a variety of Cd, Cu and Zn-bearing minerals, including metal phosphates (Gadd et al, 2012). Plant species colonised by ECM and ERM fungi can also grow successfully on highly metal-contaminated sites (Colpaert et al, 2011;Saraswat and Rai, 2011;Wen et al, 2017). They exhibit decreased sensitivity to a wide range of essential and non-essential metals including Cd, Zn, Ni and Cu, however, metal tolerance or sensitivity varies widely between plant and mycorrhizal species (Bradley et al, 1982;Bücking and Heyser, 1994;Chen and Tibbett, 2007;Frey et al, 2000;Gadd et al, 2012;Hartley-Whitaker et al, 2000;Hrynkiewicz and Baum, 2013;Sell et al, 2005;Mrnka et al, 2012).…”