Effects of arbuscular mycorrhizal inoculation on uranium and arsenic accumulation by Chinese brake fern (Pteris vittata L.) from a uranium mining-impacted soil

Abstract

A glasshouse experiment was conducted to investigate U and As accumulation by Chinese brake fern, Pteris vittata L., in association with different arbuscular mycorrhizal fungi (AMF) from a U and As contaminated soil. The soil used contains 111 mg U kg À1 and 106 mg As kg À1. P. vittata L. was inoculated with each of three AMF, Glomus mosseae, Glomus caledonium and Glomus intraradices. Two harvests were made during plant growth (two and three months after transplanting). Mycorrhizal colonization depressed plant growth particularly at the early stages. TF (transfer factor) values for As from soil to fronds were higher than 1.0, while those for roots were much lower. Despite the growth depressions, AM colonization had no effect on tissue As concentrations. Conversely, TF values for U were much higher for roots than for fronds, indicating that only very small fraction of U was translocated to fronds (less than 2%), regardless of mycorrhizal colonization. Mycorrhizal colonization significantly increased root U concentrations at both harvests. Root colonization with G. mosseae or G. intraradices led to an increase in TF values for U from 7 (non-inoculation control) to 14 at the first harvest. The highest U concentration of 1574 mg kg À1 was recorded in roots colonized by G. mosseae at the second harvest. The results suggested that P. vittata in combination with appropriate AMF would play very important roles in bioremediation of contaminated environments characterized by a multi-pollution.

Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus

“…AM fungal colonization of H. lanatus might suppress the high-affinity phosphate transport system. More recent studies indicated that colonization by G. mosseae could lower shoot As concentrations and markedly increase P/As ratios in the host plants (Liu et al, 2005;Chen et al, 2006Chen et al, , 2007. Consistently, the present study confirmed these mycorrhizal effects in maize plants (Table 2), furthermore, mycorrhiza enhanced As uptake by maize regardless of soil P supply, although the SAR of As remained unaffected when P was not added (Table 2).…”

Effects of arbuscular mycorrhizal fungi on caesium accumulation and the ascorbate-glutathione cycle of Sorghum halepense

“…De Boulois et al suggested that there was the possibility, although limited, of radiocaesium accumulation in the intraradical mycelium 19 . Chen et al also reported that AMF raised the biomass of Pteris vittata, significantly, when increased U concentrations in the root, and had a high transfer factor value, indicating that the intraradical hyphae may take advantage of microorganisms and rhizosphere microenvironment to transform radionuclides in soil effectively 20 . Additionally, it has been reported that intraradical fungal structures of Glomus lamellosum can induce the down-regulation of radiocaesium channels involved in the transport processes of radiocaesium towards the xylem 13 .…”

Dynamics of arbuscular mycorrhizal symbiosis in heavy metal phytoremediation: Meta-analytical and conceptual perspectives

“…The arbuscular mycorrhizal (AM) symbiosis, an ancient interaction between plant roots 32 and zygomycetous fungi (Morton & Benny, 1990), is recognized to benefit plants under 33 environmental stress conditions such as nutrient deficiency, drought, and heavy metal (HM) 34 pollution ( predictions for the first hypothesis, which we have designated as 'Enhanced Uptake', are that 41 plant HM uptake is increased whereas HM phytotoxicity is reached at lower soil-HM 42 concentrations in AM than non-AM plants. By contrast, the predictions for the 'Metal-Binding' 43 hypothesis are that plant HM uptake is decreased whereas HM phytotoxicity is reached at higher 44 soil-HM concentrations in AM than non-AM plants.…”