Arbuscular mycorrhiza and plant succession on zinc smelter spoil heap In Katowice-Wełnowiec

Mycorrhizal status of plants colonising the zinc wastes in Katowice was surveyed. In total 69 vascular plant species (25 families) appearing on the investigated area have been noted. More than 60% of them were mycorrhizal. Non-mycorrhizal species, such as Cardaminopsis arenosa and Silene vulgaris dominated the early successional part of the zinc heap. Tussilago farfara was the only AM plant there, however, no arbusculcs were developed at this stage. The number of AM species was increased on the 20 years old part of the zinc wastes and on the older 30-50 years old areas. AM plants constituted about 60% of the total number of species there. The frequency of particular AM species was the highest on the oldest part of the investigated area. The usefulness of the results for restoration practices was discussed. Zbadano status mikoryzowy roślin hałdy pocynkowej w Katowicach-Welnowcu. Odnotowano 69 gatunków (z 25 rodzin). Ponad 60% z nich tworzyło mikoryzę. Gatunki niemikoryzowe, jak Caidaminopsis arenosa i Silenene inflata, dominowały na młodszych częściach hałdy. Tussilago farfara był tam jedynym gatunkiem mikoryzowym. jednak nie stwierdzono u niego arbuskul. Liczba gatunków mikoryzowych wzrosła na starszych częściach. Rośliny mikoryzowe stanowiły tam około 60% wszystkich gatunków. Częstość występowania gatunków mikoryzowych była najwyższa na najstarszej części hałdy. Przedyskutowano możliwość wykorzystania otrzymanych wyników w rekultywacji tego typu terenów

Effect of combined microbes on plant tolerance to Zn-Pb contaminations

The presence and composition of soil microbial communities has been shown to have a large impact on plant–plant interactions and consequently plant diversity and composition. The goal of the present study was to evaluate impact of arbuscular mycorrhizal fungi (AMF) and nitrogen-fixing bacteria, which constitutes an essential link between the soil and the plant’s roots. A greenhouse pot experiment was conducted to evaluate the feasibility of using selected microbes to improve Hieracium pilosella and Medicago sativa growth on Zn–Pb-rich site. Results of studies revealed that biomass, the dry mass of shoots and roots, increased significantly when plants were inoculated with mycorrhizal fungi and nitrogen-fixing bacteria. The addition of Azospirillum sp. and Nostoc edaphicum without mycorrhiza suppressed plant growth. Single bacterial inoculation alone does not have a positive effect on M. sativa growth, while co-inoculation with AMF improved plant growth. Plant vitality (expressed by the performance index) was improved by the addition of microbes. However, our results indicated that even dry heat sterilization of the substratum created imbalanced relationships between soil-plant and plants and associated microorganisms. The studies indicated that AMF and N(2)-fixers can improve revegetation of heavy metal-rich industrial sites, if the selection of interacting symbionts is properly conducted. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11356-015-5094-2) contains supplementary material, which is available to authorized users

Effects of genetic modifications to flax (Linum usitatissimum) on arbuscular mycorrhiza and plant performance

Although arbuscular mycorrhizal fungi (AMF) are known for their positive effect on flax growth, the impact of genetic manipulation in this crop on arbuscular mycorrhiza and plant performance was assessed for the first time. Five types of transgenic flax that were generated to improve fiber quality and resistance to pathogens, through increased levels of either phenylpropanoids (W92.40), glycosyltransferase (GT4, GT5), or PR2 beta-1,3-glucanase (B14) or produce polyhydroxybutyrate (M50), were used. Introduced genetic modifications did not change the degree of mycorrhizal colonization as compared to parent cultivars Linola and Nike. Arbuscules were well developed in each tested transgenic type (except M50). In two lines (W92.40 and B14), a higher abundance of arbuscules was observed when compared to control, untransformed flax plants. However, in some cases (W92.40, GT4, GT5, and B14 Md), the mycorrhizal dependency for biomass production of transgenic plants was slightly lower when compared to the original cultivars. No significant influence of mycorrhiza on the photosynthetic activity of transformed lines was found, but in most cases P concentration in mycorrhizal plants remained higher than in nonmycorrhizal ones. The transformed flax lines meet the demands for better quality of fiber and higher resistance to pathogens, without significantly influencing the interaction with AMF

Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats

Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research

Stabilization of uranium(VI) at low pH by fungal metabolites : applications in environmental biotechnology

Uranium contamination of soils and water is a worldwide problem due to geology or anthropogenic release such as mining, or use of inorganic fertilizers. In situ remediation of low and moderately contaminated sites is a complicated procedure due to the complex chemistry of uranium. This study demonstrates that at pH 3.5, a fungal strain isolated from unprocessed uranium bearing shale creates hydrochemical conditions that immobilize 97% of a total of 10 mg L-1 dissolved uranium in a 0.20 μm pore system. The redistribution occurred within 10 minutes and remained for five weeks and just 12% of the inventory was retrieved in the biomass. Size exclusion chromatography of the dissolved phase identified organic substances in the range of more than 60 kD down to 100 D as a response to time of incubation. Geochemical modeling indicates formation of uranium-organic complexes where ligand size, coordination chemistry and their tendency to agglomerate determine the redistribution

Metal uptake by xerothermic plants introduced into Zn-Pb industrial wastes

The dusty surfaces of post-flotation wastes contain high concentrations of toxic compounds and spread widely if appropriate vegetation is not introduced. It has been previously established that effective restoration of such waste areas are best met by xerothermic, mycorrhiza-assisted plants (Turnau et al. Plant and Soil 305:267-280, 2008). The aim of the current study was to improve phytostabilisation practices by gaining insight into the elements uptake in plants after their change of habitat. Total Reflection X-ray Fluorescence (TXRF) was employed to evaluate element concentration in the leaves of 23 plant species growing in the wild and on Zn-Pb waste. Higher levels of heavy metals (Zn, Y, As, Pb, Cu) in plants from tailings were usually accompanied by increased Ca concentration, suggesting a possible role of this element in detoxification mechanisms. Also, when compared to grassland specimens, plants from the tailings, exhibited potassium-deficiency. Thus, K-supplementation of the waste substrata should be considered to improve plant growth. Among all the introduced plants, three grass species (Melica transsilvanica, Bromus inermis, Elymus hispidus) and one legume (Anthylis vulneraria) were the most suitable for phytostabilisation. Heavy metal-accumulating properties of Verbascum thapsus need further investigation