Effects of arbuscular mycorrhizal fungi on Agrostis capillaris grown on amended mine tailing substrate at pot, lysimeter, and field plot scales

Abstract

Applied research programs in the remediation of contaminated areas can be used also for gaining insights in the physiological and ecological mechanisms supporting the resistance of plant communities in stress conditions due to toxic elements. The research hypothesis of this study was that in the heavily contaminated but nutrient-poor substrate of mine tailing dams, the beneficial effect of inoculation with arbuscular mychorrizal fungi (AMF) is due to an improvement of phosphorus nutrition rather than to a reduction of toxic element transfer to plants. A concept model assuming a causal chain from root colonization to element uptake, oxidative stress variables, and overall plant development was used. The methodological novelty lies in coupling in a single research program experiments conducted at three scales: pot, lysimeter, and field plot, with different ages of plants at the sampling moment (six subsets of samples in all). The inoculation with AMF in expanded clay carrier had a beneficial effect on the development of plants in the amended tailing substrate heavily contaminated with toxic elements. The effect of inoculation was stronger when the quantity of expanded carrier was smaller (1 % vs. 7 % inoculum), probably because of changes in substrate features. The improvement of plant growth was due mainly to an improvement in phosphorus nutrition leading to an increase of protein concentration and decrease of oxidative stress enzyme activity (superoxide dismutase and peroxidase). In a single data subset, an effect of inoculation on the uptake of several toxic elements could be proved (decrease of As concentration in plant roots correlated with a decrease of oxidative stress independent from the effect of P concentration increase). The multi-scale approach allowed us to find differences between the patterns characterising the data subsets. These subset-specific patterns point out the existence of physiological differences between plants in different development states (as a result of sampling at different plant ages). From an applied perspective, conclusions are drawn with respect to the use of plants in the monitoring programs of contaminated areas and the use of inoculation with AMF in the remediation of tailing dams.

Heavy Metal-Induced Differential Responses to Oxidative Stress and Protection by Mycorrhization in Sunflowers Grown in Lab and Field Scales

“…It is documented that the mycorrhizae are involved in nutrient transfer to the plant by increasing root surface, extending the nutrient depletion area around the root, and making phosphorus and nitrogen sources available to the plant [43]. Recently, Doubková et al [44] found that inoculation improves plant growth and increases phosphorus uptake, which is in line with this result and our other previous results [13,14].…”

“…This is the order of pollution increase, too, similar results also being published by González-Guerrero et al [53] and, Neagoe et al [13,14]. What is interesting, in contrast with very contaminated substrates such as mine tailings [12][13][14], is that the response of oxidative stress variables for plants grown in unpolluted or slightly polluted soils presents similar patterns of variation in almost all plant parts. However, plants benefit from the effect of mycorrhizal fungi even in such substrates because the fungi enhance drought resistance in them [17,54].…”

“…Supplementing rhizosferic areas with mycorrhizal inocula is of great importance for plant growth and the stabilization of metals into the substrate. Their beneficial effects have been tested in phytoremediation experiments and shown to improve plant growth and limit HM uptake [11][12][13][14][15][16][17]. The ecotoxicological effect of HM on plants is usually tested by measuring the concentration of pollutants in soil and/or in plants, and very rarely by measuring the response of plant biochemical variables [18].…”

Response of Oxidative Stress Variables, Proteins, and Chlorophyll in Three Plant Species Caused by Moderate Soil Pollution with Toxic Elements

“…Neagoe et al [54] found similar positive correlations between protein and P nutrition in the case of four plant species grown on a metal-contaminated soil. Also, in a recent study, [55,56] it was shown that P nutrition strongly influenced the development of Agrostis capillaris on a mine tailing substrate, alleviating the oxidative stress and increasing the protein content. We found the same variation pattern in the case of the enzymatic activities, but not in the case of lipid peroxides in plantain, whose concentration was below the detection limit of the used method (Table 10).…”

Data from experiments with tailing material and Agrostis capillaris at three scales: pot, lysimeter and field plot

“…The additional value of this data is related to the fact that Agrostis capillaris is our model plant species and other raw data sets about it will be reported in the future, corresponding to existing [2,3] and future publications. This will allow improve the potential for metadata analysis.…”