Gold Nanomaterial Uptake from Soil Is Not Increased by Arbuscular Mycorrhizal Colonization of Solanum Lycopersicum (Tomato)

Abstract

Bioaccumulation of engineered nanomaterials (ENMs) by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components present in the soil might fundamentally alter the potential of plant bioaccumulation of ENMs is unclear. Here, we used two genotypes of Solanum lycopersicum (tomato), reduced mycorrhizal colonization (rmc), a mutant which does not allow arbuscular mycorrhizal fungi (AMF) colonization, and its progenitor, 76R, to examine how colonization by AMF alters trends of gold ENM bioaccumulation from a natural soil. Gold was taken up and bioaccumulated by plants of both genotypes. Gold concentrations were significantly higher in the rmc treatment although this was likely attributable to the large differences in biomass between the 76R and rmc plants. Regardless, there was little evidence that AMF played a significant role in trafficking Au ENMs into the plants. Furthermore, despite very low NH4NO3 extractable Au concentrations, Au accumulated at the root-soil interface. Although this observation would seem to suggest that ENMs may have potential to influence this particularly biologically active and important soil compartment, we observed no evidence of this here, as the 76R plants developed a robust AMF symbiosis despite accumulation of Au ENMs at the rhizoplane.

Are Nanoparticles a Threat to Mycorrhizal and Rhizobial Symbioses? A Critical Review

“…These findings demonstrated that mycorrhizal colonization can decrease Ag accumulation in Ag NP-exposed plants and moderate changes in expression level of membrane transport proteins that are possibly involved in Ag uptake. Judy et al (2016) demonstrated that AM fungi did not play a significant role in the transfer of Au NPs to tomato plants. Au NPs accumulated at the rhizoplane of plants that developed a robust (about 35%) AM fungal colonization, suggesting a low toxicity of Au NPs for AM fungi and their possible protective effects on plants.…”

Nanomaterials as Soil Pollutants

“…One additional factor, however, may be the interaction of plants with microorganisms which may also affect the uptake and effects of NP. Judy et al [101] found no effects of Au NP (26.5 nm; 25 mg kg 21 ) on arbuscular mycorrhizal fungi (AMF) colonization of Solanum lycopersicum (tomato) plants. Using two genotypes of this plant species, one without mycorrhizal colonization, they also showed that the AMF did not have a role in Au NP uptake from the test soil (pH H 2 O 8.3, 1.4% OC).…”

Stabilization of Loess Using Nano-SiO2

“…The interest in alternative materials has increased greatly in soil improvement works [ 9 , 10 ]. Nano-particles have also received special attention due to their unique properties [ 11 , 12 ]. Previous research has shown that nano-particles result in changes to physical, mechanical, and chemical properties.…”