Contribution of Arbuscular Mycorrhizal and Saprobe Fungi to the Tolerance of Eucalyptus globulus to Pb

Abstract

The application of Pb inhibited the development of mycelia of the saprobe fungi Fusarium concolor and Trichoderma koningii and the hyphal length of the arbuscular mycorrhizal fungi (AM) Glomus mosseae and G. deserticola in vitro. The application to soil of 1500 mg kg −1 of Pb decreases the dry weight, total N, P, Mg and Fe concentration and chlorophyll content of the shoot of E. globulus no inoculated with AM fungi. However, G. deserticola increased the dry weight, total nutrient concentration and chlorophyll content of the shoot, and the percentage of AM root length colonization and the succinate dehydrogenase activity of AM mycelia of E. globulus in presence of 1500 mg kg −1 of Pb, and these increases were higher when G. deserticola was inoculated together with T. koningii. The application to soil of 3000 mg kg −1 of Pb decreased the shoot dry weight and AM colonization of E. globulus in all treatments tested. Pb was accumulated in the stem more than in the leaves of E. globulus. In presence of 1500 mg kg −1 of Pb the highest accumulation of this metal in the stem took place when E. globulus was colonized with G. deserticola. In conclusion, the possibility to increase Lead accumulation in stem is very attractive for phytoextraction function, the saprobe fungi, AM and their interaction may have a potential role in elevating phytoextraction efficiency and stimulate plant growth under adverse conditions such as lead contaminated soil.

Differences in the effects of three arbuscular mycorrhizal fungal strains on P and Pb accumulation by maize plants

“…Concerning AM effect specifically on Pb uptake, a reduction of its concentrations in plant shoots was repeatedly reported (Andrade et al 2004;Hovsepyan and Greipsson 2004;Karagiannidis and Nikolaou 2000;Malcová et al, 2003;Wang et al 2005;Zhang et al 2005). Some studies, however, failed to reveal the differences in Pb uptake between inoculated and uninoculated plants (Díaz et al 1996;Weissenhorn et al 1995) or demonstrated even increased Pb concentrations in shoot tissues of inoculated plants (Arriagada et al 2005;Chen et al 2005;Rydlová and Vosátka 2003;Wang et al 2005). In root tissues, higher Pb concentrations were often reported for AM-inoculated plants (e.g.…”

Contribution of Arbuscular Mycorrhizal and Saprobe Fungi to the Aluminum Resistance of Eucalyptus globulus

“…The synergic effect of saprobe fungi belonging to Fusarium concolor and Trichoderma koningii on the arbuscular mycorrhizal colonization of root has already been observed (Arriagada et al, 2005;García-Romera et al, 1998). In this study, the fact that saprobe fungi could absorb aluminum and increase root arbuscular mycorrhizal colonization may explain why combined inoculation of G. deserticola and T. koningii increased the tolerance of E. globulus to the application of 1,500 mg kg −1 .…”

“…Their importance lies in the large microbial biomass they supply to soil and in their capacity to degrade toxic substances (Madrid, De La Rubia, & Martinez, 1996;Wainwright, 1992). Some experimental results confirm the existence of synergistic effects of the saprobe fungi Fusarium concolor and Trichoderma koningii on plant roots colonized by AMF (Arriagada et al, 2005;García-Romera et al, 1998).…”

“…However, these saprobe fungi were able to absorb aluminum from the culture media, indicating the ability of these fungi to take aluminum up from the media. In fact, some microorganisms are able to absorb and to store heavy metals in their fungal structures (Alexander, 1999;Arriagada et al, 2005; J. W. Huang, C. P. Huang, & Morehart, 1990). High amounts of aluminum in soil decrease plant growth and nutrient uptake (Cumming & Weinstein, 1990a;Fabig, 1982;Hentschel, Godbold, Marschner, Schlegel, & Jentschke, 1993).…”

“…Their symbiosis benefits plant growth, particularly through enhanced phosphorus, water and mineral nutrient uptake (Li, Marschner, & George, 1991;Pearson & Jakobsen, 1993) even under stressful environmental conditions (Smith & Read, 1997). It is also recognized that AMF protect plants against the toxic effects of excessive concentrations of toxic compounds including heavy metals (Arriagada, Herrera, & Ocampo, 2005;Haselwandter & Berreck, 1994;Heggo, Angle, & Chaney, 1990;Rivera-Becerril et al, 2002).…”