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- Application of manure and compost to contaminated soils and its effect on zinc accumulation by Solanum nigrum inoculated with arbuscular mycorrhizal fungiPublication . Marques, Ana P. G. C.; Oliveira, Rui S.; Rangel, António O. S. S.; Castro, Paula M. L.
- Zinc accumulation in Solanum Nigrum is enhanced by different arbuscular mycorrhizal fungiPublication . Marques, Ana P. G. C.; Oliveira, Rui S.; Rangel, António O.S.S.; Castro, Paula M.L.Solanum nigrum was found to proliferate in sediments with high levels of metal pollution. The effect of Zn on plant growth and tissue metal accumulation was assessed. The response of the plant to the inoculation with four different isolates of arbuscular mycorrhizal fungi (AMF) (Glomus sp. BEG140, Glomus claroideum, Glomus mosseae and Glomus intraradices) was studied. While the isolates of AMF did not have a significant (P < 0.05) influence on mycorrhizal colonisation, increasing Zn concentration to high levels (500 and 1000 mg kg 1) induced significant (P < 0.05) decrease of the AMF colonisation. In general, the presence of AMF did not affect the growth and biomass of S. nigrum individuals. However, the level of metal in the matrix affected S. nigrum growth; plants grown at 100 mg kg 1 had significantly (P < 0.05) lower leaf, stem, root and total biomass than control ones and plants growing at 500 and 1000 mg kg 1 had the significantly (P < 0.05) lowest biomass. Plants inoculated with the AMF G. claroideum and G. intraradices presented significantly (P < 0.05) higher Zn accumulation in all plant tissues. In general, the stem tissues had the higher Zn content while the leaves registered the lowest values, which indicate a high translocation of the metal. AMF inoculation had no significant (P < 0.05) influence on the metal translocation within the plant. This study suggests that inoculation with the AMF G. claroideum or G. intraradices, can enhance the Zn accumulation in the tissues of S. nigrum, not affecting the plant translocation capacities.
- Application of manure and compost to contaminated soils and its effect on zinc accumulation by Solanum nigrum inoculated with arbuscular mycorrhizal fungiPublication . Marques, Ana P. G. C.; Oliveira, Rui S.; Rangel, António O. S. S.; Castro, Paula M. L.Zn accumulation in Solanum nigrum grown in naturally contaminated soil in the presence of different types of organic amendments was assessed. Under the same conditions, the response of the plant to inoculation with two different isolates of arbuscular mycorrhizal fungi (AMF) (Glomus claroideum and Glomus intraradices) was also evaluated. S. nigrum grown in the non-amended soil always presented higher Zn accumulation in the tissues, with the addition of amendments inducing reductions of up to 80 and 40%, for manure and compost, respectively, and enhancing plant biomass yields. The establishment of S. nigrum in the Zn contaminated soil combined with the application of amendments led to a 70-80% reduction in the amount of Zn leached through the soil. The use of S. nigrum in combination with manure appeared as an effective method for reducing the effects of soil contamination, diminishing Zn transfer to other environmental compartments via percolation.
- EDDS and EDTA-enhanced zinc accumulation by solanum nigrum inoculated with arbuscular mycorrhizal fungi grown in contaminated soilPublication . Marques, Ana P. G. C.; Oliveira, Rui S.; Samardjieva, Kalina A.; Pissarra, José; Rangel, António O. S. S.; Castro, Paula M. L.The effect of two different chelating agents [EDTA and EDDS S,S-ethylenediaminedissucinic acid)] on Zn tissue accumulation in Solanum nigrum L. grown in a naturally contaminated soil was assessed. Under those conditions, the response of the plant to the inoculation with two different isolates of arbuscular mycorrhizal fungi (AMF) – Glomus claroideum and Glomus intraradices – was also studied. Plants grown in the local contaminated soil (Zn levels of 433 mg Kgˉ¹1) accumulated up to 1191 mg Kgˉ¹ of Zn in the roots, 3747 mg Kgˉ¹ in the stems and 3409 mg Kgˉ¹ in the leaves. S. nigrum plants grown in the same soil spiked with extra Zn (Zn levels of 964 mg Kgˉ¹) accumulated up to 4735, 8267 and 7948 mg Zn Kgˉ¹ in the leaves, stems and roots, respectively. The addition of EDTA promoted an increase in the concentration of Zn accumulated by S. nigrum of up to 231% in the leaves, 93% in the stems and 81% in the roots, while EDDS application enhanced the accumulation in leaves, stems and roots up to 140, 124 and 104%, respectively. In the stems, the presence of Zn was predominantly detected in the cortex collenchyma cells, the starch sheath and the internal phloem and xylem parenchyma, and the addition of chelating agents did not seem to have an effect on the localisation of accumulation sites. The devise of a chelate-enhanced phytoextraction strategy, using chelating agents and AMF, is discussed.
- Different native arbuscular mycorrhizal fungi influence the coexistence of two plant species in a highly alkaline anthropogenic sedimentPublication . Oliveira, Rui S.; Castro, Paula M. L.; Dodd, John C.; Vosátka, MiroslavDifferent species of arbuscular mycorrhizal fungi (AMF) can produce different amounts of extraradical mycelium (ERM) with differing architectures. They also have different efficiencies in gathering phosphate from the soil. These differences in phosphate uptake and ERM length or architecture may contribute to differential growth responses of plants and this may be an important contributor to plant species coexistence. The effects of the development of the ERM of AMF on the coexistence of two co-occurring plant species were investigated in root-free hyphal chambers in a rhizobox experimental unit. The dominant shrub (Salix atrocinerea Brot.) and herbaceous (Conyza bilbaoana J. Re´my) plant species found in a highly alkaline anthropogenic sediment were studied in symbiosis with four native AMF species (Glomus intraradices BEG163, Glomus mosseae BEG198, Glomus geosporum BEG199 and Glomus claroideum BEG210) that were the most abundant members of the AMF community found in the sediment. DifferentAMFspecies did not influence total plant productivity (sum of the biomass of C. bilbaoana and S. atrocinerea), but had a great impact on the individual biomass of each plant species. The AMF species with greater extracted ERMlengths (G. mosseae BEG198, G. claroideum BEG210 and the four mixed AMF) preferentially benefited the plant species with a high mycorrhizal dependency (C. bilbaoana), while the AMF species with the smallest ERM length (G. geosporum BEG199) benefited the plant species with a low mycorrhizal dependency (S. atrocinerea). Seed production of C. bilbaoana was only observed in plants inoculated with G. mosseae BEG198, G. claroideum BEG210 or the mixture of the four AMF. Our results show that AMF play an important role in the reproduction of C. bilbaoana coexisting with S. atrocinerea in the alkaline sediment and have the potential to stimulate or completely inhibit seed production. The community composition of native AMF and the length of the mycelium they produce spreading from roots into the surrounding soil can be determinant of the coexistence of naturally co-occurring plant species.
- Solanum nigrum grown in contaminated soil: effect of arbuscular mycorrhizal fungi on zinc accumulation and histolocalisationPublication . Marques, Ana P. G. C.; Oliveira, Rui S.; Samardjieva, Kalina A.; Pissarra, José; Rangel, António O. S. S.; Castro, Paula M.L.Zn tissue accumulation in Solanum nigrum grown in a non-contaminated and a naturally contaminated Zn matrix and the effect of inoculation with different arbuscular mycorrhizal fungi (AMF) on metal uptake were assessed. S. nigrum grown in the contaminated soil always presented higher Zn accumulation in the tissues, accumulating up to 1622 mg Zn kg 1. The presence of both Glomus claroideum and Glomus intraradices enhanced the uptake and accumulation of Zn by S. nigrum (up to 83 and 49% higher Zn accumulation, respectively). The main deposits of the metal were found in the intercellular spaces and in the cell walls of the root tissues, as revealed by autometallography, with the inoculation with different AMF species causing no differences in the location of Zn accumulation. These findings indicate that S. nigrum inoculated with selected heavy metal tolerant AMF presents extracting and accumulating capacities, constituting a potentially suitable remediation method for Zn polluted soils.
- Genetic, phenotypic and functional variation within a Glomus geosporum isolate cultivated with or without the stress of a highly alkaline anthropogenic sedimentPublication . Oliveira, Rui S.; Boyer, Louisa Robinson; Carvalho, Maria F.; Jeffries, Peter; Castro, Paula M.L.; Vosátka, Miroslav; Dodd, John C.Genetic, phenotypic and functional variation in a Glomus geosporum isolate obtained from a highly alkaline anthropogenic sediment was investigated. Two cultivation lineages of G. geosporum (BEG199 and BEG211) were created by sub-culturing with or without the stress of the sediment. Genetic variation was assessed on spores from both cultivation lineages in the large sub-unit rRNA gene D2 region using PCR-single strand conformational polymorphism (PCR-SSCP) and sequencing. Phenotypical and functional variation of the cultivation lineages were assessed after inoculation onto Conyza bilbaoana. The sequence diversity obtained in G. geosporum BEG211 was significantly different from that obtained in G. geosporum BEG199. Glomus geosporum BEG199 was more effective than G. geosporum BEG211 in promoting the growth of C. bilbaoana in inert substrate and in increasing its leaf phosphorus concentration when the plant was grown in sediment. After inoculation onto C. bilbaoana, G. geosporum BEG199 colonised the roots to a greater extent, produced a significantly larger number of spores and presented a greater length of extraradical mycelium than G. geosporum BEG211. The results indicate that environmental conditions under which arbuscular mycorrhizal fungi (AMF) are cultivated can influence their effects in host plants. Also, AMF might quickly lose gained-tolerance to environmental stresses when maintained without the selective pressure of those stresses. This study has implications for the production of commercial inoculum of AMF and for the maintenance of AMF cultures. The results indicate that inoculum of AMF should be produced and AMF cultures should be maintained in substrates or media containing the original edaphic stresses.