Uptake of Atrazine and Cadmium from Soil by Maize (Zea mays L.) in Association with the Arbuscular Mycorrhizal Fungus Glomus etunicatum

Abstract

A greenhouse pot experiment was carried out to investigate the effect of the arbuscular mycorrhizal fungus Glomus etunicatum on the uptake of atrazine (ATR) and cadmium (Cd) from soil by maize (Zea mays L.). Mycorrhizal colonization led to an increase in the accumulation of Cd and ATR in maize roots but a decrease in the shoots. Atrazine alleviated the adverse effects of Cd on maize growth, and this was more pronounced in the inoculated plants. An increase in Cd accumulation by maize roots was observed when ATR was also present. After harvest, the residual ATR concentration in the soil decreased markedly. With mycorrhizal inoculation the amount of residual ATR decreased more in the bulk soil but less in the rhizosphere soil compared to the noninoculated controls. Cadmium application significantly decreased the ATR residual concentrations in both the rhizosphere and bulk soils irrespective of inoculation treatment.

Influence of Glomus etunicatum/Zea mays mycorrhiza on atrazine degradation, soil phosphatase and dehydrogenase activities, and soil microbial community structure

“…There was a significant decrease in the residual atrazine concentration in the soil after plant harvest (P < 0.05) and this became more evident with inoculation, which was consistent with our previous findings for atrazine by bulk cultivation (Huang et al, 2006). Atrazine in soil decreased more in the extraradical mycelium compartment than in the mycorrhizal root compartment when the atrazine addition rate to soil was 5.0 mg kg À1 .…”

“…It has been reported that in rhizosphere soil atrazine degradation is associated with higher dehydrogenase (Seibert et al, 1991;Singh et al, 2004) and phosphatase activities (Perucei et al, 1988;Bielinska and Pranagal, 2007), and atrazine can influence the populations of certain microbial groups (Ros et al, 2006). We observed in our previous studies that atrazine dissipation in soil was enhanced by AM inoculation (Huang et al, 2006). We therefore hypothesized that increased dissipation of atrazine in soil might contribute to: (1) specific effects of mycorrhizal roots and extraradical mycelium on atrazine dissipation; and/or (2) modification of the effects on soil enzyme activities and microbial community structure resulting from mycorrhizal inoculation.…”

Insight into the Role of Arbuscular Mycorrhizal Fungi in Sustainable Agriculture

“…Unlike other pesticides, the herbicide atrazine at lower concentration decreases mycorrhizal colonization, whereas at higher concentration, it stimulates colonization (Huang et al 2006(Huang et al , 2007. However, it has been speculated that the application of higher concentrations of atrazine tends to induce tolerance in AM fungi, although the real mechanism behind the varied effect is yet to be elucidated (Huang et al 2007 ).…”

A 60-year journey of mycorrhizal research in China: Past, present and future directions

“…Pot experiments demonstrated that dual inoculation of M. sativa with G. versiforme or G. caledonium and Rhizobium meliloti achieved the most efficient removal of polychlorinated biphenyls from contaminated soils [201,202]. Atrazine accumulation was shown to decrease in maize shoots but increase in roots when the plant was associated with Glomus etunicatum [203,204]. More atrazine metabolites, deethylatrazine and deisopropylatrazine, were metabolized in AM-maize roots, leading to atrazine dissipation in the rhizosphere and bulk soils [204].…”