Contribution of the arbuscular mycorrhizal symbiosis to heavy metal phytoremediation

Abstract

High concentrations of heavy metals (HM) in the soil have detrimental effects on ecosystems and are a risk to human health as they can enter the food chain via agricultural products or contaminated drinking water. Phytoremediation, a sustainable and inexpensive technology based on the removal of pollutants from the environment by plants, is becoming an increasingly important objective in plant research. However, as phytoremediation is a slow process, improvement of efficiency and thus increased stabilization or removal of HMs from soils is an important goal. Arbuscular mycorrhizal (AM) fungi provide an attractive system to advance plant-based environmental clean-up. During symbiotic interaction the hyphal network functionally extends the root system of their hosts. Thus, plants in symbiosis with AM fungi have the potential to take up HM from an enlarged soil volume. In this review, we summarize current knowledge about the contribution of the AM symbiosis to phytoremediation of heavy metals.

Antioxidant activity and gene expression associated with cadmium toxicity in wheat affected by mycorrhizal fungus

“…These results showed that chelation of Cd inside the fungus or adsorption of Cd to chitin in the fungal cell wall caused accumulation of Cd in root and prevented the Cd translocation from root to shoot. Similarly, in AMF, there is evidence suggesting that fungal hyphae components may provide additional detoxification mechanisms by storing toxic compounds (Göhre, Paszkowski, 2006). F. mosseae inoculation reduced root and shoot Cd at all Cd levels in the soil.…”

“…The colonization by F. mosseae increased total plant dry matter at different soil Cd concentrations and this increase was significant under 0 and 0.3 mM Cd, in comparison with non-colonized plants. It is well known that the association of plants with mycorrhizal fungi modifies plant responses to metal-induced stress which leads to increasing tolerance in metal-contaminated soils (Göhre, Paszkowski, 2006). The uptake of metals by mycorrhizal plants and toxicity amelioration are major aspects to be considered by those interested in phytoremediation technologies (Ali et al, 2013).…”

Arbuscular mycorrhizal fungi as a tool to ameliorate the phytoremediation potential of poplar: biochemical and molecular aspects

“…Arbuscular mycorrhizal fungi (AMF) form associations with the roots of the vast majority of land plants; the fungus colonizes the roots and forms arbuscules within root cortical cells thus improving plant nutrient uptake, especially phosphorus (Smith & Read 1997). Moreover, increasing evidence shows that symbiotic fungi contribute to plant adaptation to multiple biotic and abiotic stresses (Gohre & Paszkowski 2006, Lebeau et al 2008, Lingua et al 2002, Liu et al 2007, Rodriguez & Redman 2008, Smith et al 2010). In the case of HMs, the beneficial ef-fect varies according to plant and fungal species, metal and concentration (Bois et al 2005, Lebeau et al 2008, Takacs et al 2005, Todeschini et al 2007.…”

Synergistic effect of phosphate solubilizing rhizobacteria and arbuscular mycorrhiza on growth and yield of wheat plants

“…As a result, mycorrhizal plants are often more competitive and are able to tolerate environmental stresses compared to non-mycorrhizal plants. The application of AM fungi led to noteworthy enhancements on plant growth, vigour, nutrient and water uptake, disease resistance and drought tolerance (Raj et al, 1981;Jeffries et al, 2003;Sanchez-Blanco et al, 2004;Göhre and Paszkowski, 2006;Wu and Xia, 2006). Plant growth promoting rhizobacteria (PGPR), especially phosphate solubilizing bacteria (PSB), which reside in the plant rhizosphere, increase the availability of P for the plants by solubilization of bound P in soil (Illmer et al, 1995;Rodriguez and Fraga, 1999;Igual et al, 2001).…”