Specific arbuscular mycorrhizal fungal–plant interactions determine radionuclide and metal transfer into Plantago lanceolata

Abstract

Industrial activity has left a legacy of pollution by radionuclides and heavy metals.The exposure of terrestrial environments to increased levels of ionising radiation and toxic elements is of concern, not only because of the immediate effects to biota but also because of the potential risk of mobilisation into higher levels of a food chain.Here, we present a study that extends our knowledge of how arbuscular mycorrhizal fungi contribute to the mobilisation of non-essential elements in environments such as former mine sites, and provides a perspective that will be of interest for the management and remediation of such sites. Summary• Accumulation and transfer of long-lived radionuclides and toxic metals in terrestrial environments is of major concern because of potential mobilisation into food chains. In this study, we aimed to compare the role of four different arbuscular mycorrhizal fungal (AMF) cultures on the transfer of non-essential elements into Plantago lanceolata from a naturally contaminated soil source.• Soil from an abandoned uranium ( 238 U) mine was collected as a natural source of 238 U, thorium ( 232 Th), arsenic (As) and lead (Pb). P. lanceolata was inoculated with four AMF cultures (Rhizophagus irregularis DAOM181602, Acaulospora longula BEG8, Scutellospora calospora BEG245 and Funneliformis mosseae BEG12) to compare the uptake and transfer from root to shoot. Inductively coupled plasma (ICP) mass spectroscopy and ICP-absorption emission spectroscopy analyses provided quantification of total elemental concentrations in soil and plant tissues. • Two of the AMF cultures, A. longula and F. mosseae, had contrasting roles in toxic element partitioning in plant tissue of P. lanceolata. F. mosseae increased the accumulation of 238 U, 232 Th, Pb, As and Cu in shoots whereas A. longula induced increased partitioning of 232 Th, Ca, Fe and Zn in roots. The inoculation treatments and the differential accumulation of these elements had no significant effect on plant biomass. • The use of different AMF cultures in enhancing phytoremediation of contaminated environments requires a wider understanding of the contribution of different AMF cultures to non-essential element acquisition as well as to plant nutrition.

The value of synchrotron radiation X‐ray techniques to explore microscale chemistry for ecology and evolution research

“…Additionally, the contamination of thin sections by artifacts introduced during sample preparation will obscure data quality. Our current research aimed to identify cellular hotspots of toxic metals and radionuclides within plant specimens that are native or can grow and tolerate in metal‐ and radionuclide‐contaminated soil at an abandoned uranium mine in Cornwall, UK (Davies et al, 2018; Rosas‐Moreno et al, 2021). Synchrotron XRF was used to elucidate the soil–plant transfer mechanisms that may govern a plant's ability to tolerate elevated soil pollutant concentrations (Figure 3).…”

“…For the P. lanceolata root section preparation, seedlings planted in South Terras soil were additionally fed with 100 ml of Hoagland's solution to provide sufficient essential nutrients for optimal plant growth within a Panasonic versatile environmental growth chamber (MLR‐352‐PE Series) for 12 weeks under controlled light, humidity, and temperature conditions, exactly as described previously (Rosas‐Moreno et al, 2021). Once ready to harvest, roots were fully rinsed several times in HPLC‐grade deionized water to remove as many adhering soil and clay particles as possible.…”

Role of Ectomycorrhizal Symbiosis Behind the Host Plants Ameliorated Tolerance Against Heavy Metal Stress

“…When inoculated with the same host plant, further ribonuclease retention in roots or shoot transfer varies depending upon different AM fungal species. For bioremediation purpose, the utilization of mycorrhizal symbiosis in enhancing phytoaccumulation of ribonuclides requires further studies ( Rosas-Moreno et al, 2021 ). Similarly, the impact of ECM symbiosis over radionuclides accumulation in their host plants is reported in a few studies but remains unclear and needs focus studies ( Ogo et al, 2018 ).…”