WorldWideScience

Sample records for arbuscular mycorrhizal colonization

  1. Colonization of new land by arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Nielsen, Knud Brian; Kjøller, Rasmus; Bruun, Hans Henrik;

    2016-01-01

    was significantly lower on the artificial island than on the neighboring natural island, indicating that richness of the colonizing AM fungal community is restricted by limited dispersal. The AM fungal communities colonizing the new island appeared to be a non-random subset of communities on the natural and much......The study describes the primary assembly of arbuscular mycorrhizal communities on a newly constructed island Peberholm between Denmark and Sweden. The AM fungal community on Peberholm was compared with the neighboring natural island Saltholm. The structure of arbuscular mycorrhizal communities...... was assessed through 454 pyrosequencing. Internal community structure was investigated through fitting the rank-abundance of Operational Taxonomic Units to different models. Heterogeneity of communities within islands was assessed by analysis of group dispersion. The mean OTU richness per sample...

  2. Plant interspecific differences in arbuscular mycorrhizal colonization as a result of soil carbon addition.

    Science.gov (United States)

    Eschen, René; Müller-Schärer, Heinz; Schaffner, Urs

    2013-01-01

    Soil nutrient availability and colonization by arbuscular mycorrhizal fungi are important and potentially interacting factors shaping vegetation composition and succession. We investigated the effect of carbon (C) addition, aimed at reducing soil nutrient availability, on arbuscular mycorrhizal colonization. Seedlings of 27 plant species with different sets of life-history traits (functional group affiliation, life history strategy and nitrophilic status) were grown in pots filled with soil from a nutrient-rich set-aside field and amended with different amounts of C. Mycorrhizal colonization was progressively reduced along the gradient of increasing C addition in 17 out of 27 species, but not in the remaining species. Grasses had lower colonization levels than forbs and legumes and the decline in AM fungal colonization was more pronounced in legumes than in other forbs and grasses. Mycorrhizal colonization did not differ between annual and perennial species, but decreased more rapidly along the gradient of increasing C addition in plants with high Ellenberg N values than in plants with low Ellenberg N values. Soil C addition not only limits plant growth through a reduction in available nutrients, but also reduces mycorrhizal colonization of plant roots. The effect of C addition on mycorrhizal colonization varies among plant functional groups, with legumes experiencing an overproportional reduction in AM fungal colonization along the gradient of increasing C addition. We therefore propose that for a better understanding of vegetation succession on set-aside fields one may consider the interrelationship between plant growth, soil nutrient availability and mycorrhizal colonization of plant roots.

  3. Arbuscular mycorrhizal colonization improves growth and biochemical profile in Acacia arabica under salt stress

    Directory of Open Access Journals (Sweden)

    Promita Datta

    2014-12-01

    Full Text Available This study elucidated the individual and mixed mycorrhizal effects of two arbuscular mycorrhizal (AM isolates on growth and biochemical status of Acacia arabica under salinity stress gradients. Salt treatment provided in soil hampered legume growth and its biochemical status. But, mycorrhizal colonizations in plant root system reduced the extent of deleterious salt effect and also helped in plant growth enhancement. Additionally, mixed mycorrhizal association (Glomus mosseae + Glomus fasciculatum responded better towards osmolyte accumulation and in salt stress alleviation. Due to individual and mixed mycorrhizal colonizations in A. arabica; protein, carbohydrate and reducing sugar acquisitions were found maximum at soil salinity of 5.94 dS/m over corresponding non-mycorrhizal plant. However, mixed AM inoculation accumulated proline content and improved dry biomass to a higher magnitude at the highest soil salinity level. Mixed AM (G. mosseae + G. fasciculatum colonization improved maximum amount of total chlorophyll (20.94%, protein (19.72%, carbohydrate (23.83%, reducing sugar (17.60% at soil salinity of 5.94 dS/m and dry biomass (20.35%, proline content (10.99% at salinity level of 8.26 dS/m when compared with non-mycorrhizal counterpart. Greater magnitude of AM root colonization was found in mixed AM treated plant and may be responsible for more improvement in growth and biochemical status and consequently mitigated adverse salt effect better.

  4. Suppression of allene oxide synthase 3 in potato increases degree of arbuscular mycorrhizal fungal colonization.

    Science.gov (United States)

    Morcillo, Rafael Jorge León; Navarrete, María Isabel Tamayo; Bote, Juan Antonio Ocampo; Monguio, Salomé Prat; García-Garrido, José Manuel

    2016-01-15

    Arbuscular mycorrhizal (AM) is a mutually beneficial interaction among higher plants and soil fungi of the phylum Glomeromycota. Numerous studies have pointed that jasmonic acid plays an important role in the development of the intraradical fungus. This compound belongs to a group of biologically active compounds known as oxylipins which are derived from the oxidative metabolism of polyunsaturated fatty acids. Studies of the regulatory role played by oxylipins in AM colonization have generally focused on jasmonates, while few studies exist on the 9-LOX pathway of oxylipins during AM formation. Here, the cDNA of Allene oxide synthase 3 (AOS3), a key enzyme in the 9-LOX pathway, was used in the RNA interference (RNAi) system to transform potato plants in order to suppress its expression. Results show increases in AOS3 gene expression and 9-LOX products in roots of wild type potato mycorrhizal plants. The suppression of AOS3 gene expression increases the percentage of root with mycorrhizal colonization at early stages of AM formation. AOS3 RNA interference lead to an induction of LOXA and 13-LOX genes, a reduction in AOS3 derived 9-LOX oxylipin compounds and an increase in jasmonic acid content, suggesting compensation between 9 and 13-LOX pathways. The results in a whole support the hypothesis of a regulatory role for the 9-LOX oxylipin pathway during mycorrhization.

  5. Suppression of allene oxide synthase 3 in potato increases degree of arbuscular mycorrhizal fungal colonization.

    Science.gov (United States)

    Morcillo, Rafael Jorge León; Navarrete, María Isabel Tamayo; Bote, Juan Antonio Ocampo; Monguio, Salomé Prat; García-Garrido, José Manuel

    2016-01-15

    Arbuscular mycorrhizal (AM) is a mutually beneficial interaction among higher plants and soil fungi of the phylum Glomeromycota. Numerous studies have pointed that jasmonic acid plays an important role in the development of the intraradical fungus. This compound belongs to a group of biologically active compounds known as oxylipins which are derived from the oxidative metabolism of polyunsaturated fatty acids. Studies of the regulatory role played by oxylipins in AM colonization have generally focused on jasmonates, while few studies exist on the 9-LOX pathway of oxylipins during AM formation. Here, the cDNA of Allene oxide synthase 3 (AOS3), a key enzyme in the 9-LOX pathway, was used in the RNA interference (RNAi) system to transform potato plants in order to suppress its expression. Results show increases in AOS3 gene expression and 9-LOX products in roots of wild type potato mycorrhizal plants. The suppression of AOS3 gene expression increases the percentage of root with mycorrhizal colonization at early stages of AM formation. AOS3 RNA interference lead to an induction of LOXA and 13-LOX genes, a reduction in AOS3 derived 9-LOX oxylipin compounds and an increase in jasmonic acid content, suggesting compensation between 9 and 13-LOX pathways. The results in a whole support the hypothesis of a regulatory role for the 9-LOX oxylipin pathway during mycorrhization. PMID:26629611

  6. Arbuscular mycorrhizal colonization, plant chemistry, and aboveground herbivory on Senecio jacobaea

    NARCIS (Netherlands)

    Reidinger, S.; Eschen, R.; Gange, A.C.; Finch, P.; Bezemer, T.M.

    2012-01-01

    Arbuscular mycorrhizal fungi (AMF) can affect insect herbivores by changing plant growth and chemistry. However, many factors can influence the symbiotic relationship between plant and fungus, potentially obscuring experimental treatments and ecosystem impacts. In a field experiment, we assessed AMF

  7. Red list plants: colonization by arbuscular mycorrhizal fungi and dark septate endophytes.

    Science.gov (United States)

    Fuchs, B; Haselwandter, K

    2004-08-01

    Since information concerning the mycorrhization of endangered plants is of major importance for their potential re-establishment, we determined the mycorrhizal status of Serratula tinctoria (Asteraceae), Betonica officinalis (Lamiaceae), Drosera intermedia (Droseraceae) and Lycopodiella inundata (Lycopodiaceae), occurring at one of two wetland sites (fen meadow and peat bog), which differed in soil pH and available P levels. Root colonization by arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) was quantified. Colonization by AMF appeared to be more frequent in the fen meadow than in the peat bog, and depended on the host plant. Roots of S. tinctoria and B. officinalis were well colonized by AMF in the fen meadow (35-55% root length) and both arbuscules and vesicles were observed to occur in spring as well as in autumn. In the peat bog, L. inundata showed a low level of root colonization in spring, when vesicles were found frequently but no arbuscules. In roots of D. intermedia from the peat bog, arbuscules and vesicles were observed, but AMF colonization was lower than in L. inundata. In contrast, the amount of AMF spores extracted from soil at the peat bog site was higher than from the fen meadow soil. Spore numbers did not differ between spring and autumn in the fen meadow, but they were higher in spring than in autumn in the peat bog. Acaulospora laevis or A. colossica and Glomus etunicatum were identified amongst the AMF spores extracted from soil at the two sites. S. tinctoria and B. officinalis roots were also regularly colonized by DSE (18-40% root length), while L. inundata was only rarely colonized and D. intermedia did not seem to be colonized by DSE at all. PMID:15221579

  8. Intraradical colonization by arbuscular mycorrhizal fungi triggers induction of a lipochitooligosaccharide receptor

    Science.gov (United States)

    Rasmussen, S. R.; Füchtbauer, W.; Novero, M.; Volpe, V.; Malkov, N.; Genre, A.; Bonfante, P.; Stougaard, J.; Radutoiu, S.

    2016-07-01

    Functional divergence of paralogs following gene duplication is one of the mechanisms leading to evolution of novel pathways and traits. Here we show that divergence of Lys11 and Nfr5 LysM receptor kinase paralogs of Lotus japonicus has affected their specificity for lipochitooligosaccharides (LCOs) decorations, while the innate capacity to recognize and induce a downstream signalling after perception of rhizobial LCOs (Nod factors) was maintained. Regardless of this conserved ability, Lys11 was found neither expressed, nor essential during nitrogen-fixing symbiosis, providing an explanation for the determinant role of Nfr5 gene during Lotus-rhizobia interaction. Lys11 was expressed in root cortex cells associated with intraradical colonizing arbuscular mycorrhizal fungi. Detailed analyses of lys11 single and nfr1nfr5lys11 triple mutants revealed a functional arbuscular mycorrhizal symbiosis, indicating that Lys11 alone, or its possible shared function with the Nod factor receptors is not essential for the presymbiotic phases of AM symbiosis. Hence, both subfunctionalization and specialization appear to have shaped the function of these paralogs where Lys11 acts as an AM-inducible gene, possibly to fine-tune later stages of this interaction.

  9. Colonization with Arbuscular Mycorrhizal Fungi Promotes the Growth of Morus alba L. Seedlings under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2015-03-01

    Full Text Available Morus alba L. is an important tree species planted widely in China because of its economic value. In this report, we investigated the influence of two arbuscular mycorrhizal fungal (AMF species, Glomus mosseae and Glomus intraradices, alone and together, on the growth of M. alba L. seedlings under greenhouse conditions. The growth parameters and physiological performance of M. alba L. seedlings were evaluated 90 days after colonization with the fungi. The growth and physiological performance of M. alba L. seedlings were significantly affected by the AMF species. The mycorrhizal seedlings were taller, had longer roots, more leaves and a greater biomass than the non-mycorrhizae-treated seedlings. In addition, the AMF species-inoculated seedlings had increased root activity and a higher chlorophyll content compared to non-inoculated seedlings. Furthermore, AMF species colonization increased the phosphorus and nitrogen contents of the seedlings. In addition, simultaneous root colonization by the two AMF species did not improve the growth of M. alba L. seedlings compared with inoculation with either species alone. Based on these results, these AMF species may be applicable to mulberry seedling cultivation.

  10. Gold Nanomaterial Uptake from Soil Is Not Increased by Arbuscular Mycorrhizal Colonization of Solanum Lycopersicum (Tomato

    Directory of Open Access Journals (Sweden)

    Jonathan D. Judy

    2016-04-01

    Full Text Available Bioaccumulation of engineered nanomaterials (ENMs by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components present in the soil might fundamentally alter the potential of plant bioaccumulation of ENMs is unclear. Here, we used two genotypes of Solanum lycopersicum (tomato, reduced mycorrhizal colonization (rmc, a mutant which does not allow arbuscular mycorrhizal fungi (AMF colonization, and its progenitor, 76R, to examine how colonization by AMF alters trends of gold ENM bioaccumulation from a natural soil. Gold was taken up and bioaccumulated by plants of both genotypes. Gold concentrations were significantly higher in the rmc treatment although this was likely attributable to the large differences in biomass between the 76R and rmc plants. Regardless, there was little evidence that AMF played a significant role in trafficking Au ENMs into the plants. Furthermore, despite very low NH4NO3 extractable Au concentrations, Au accumulated at the root-soil interface. Although this observation would seem to suggest that ENMs may have potential to influence this particularly biologically active and important soil compartment, we observed no evidence of this here, as the 76R plants developed a robust AMF symbiosis despite accumulation of Au ENMs at the rhizoplane.

  11. Two Arbuscular Mycorrhizal Fungi Colonizing Maize Under Different Phosphorus Regimes in a Compartment Cultivation System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A modified glass bead compartment cultivation system was used to compare some chemical and biological properties of the two arbuscular mycorrhizal (AM) fungi Glomus mosseae and Glomus versiforme using maize (Zea mays) as the host plant with four added levels of available phosphorus (P). The proportion of host plant root length infected was determined at harvest. Shoot and root yields and nutrient concentrations were determined, together with the nutrient concentrations in the AM fungal external mycelium. The morphology of various mycorrhizal structures of the two AM fungi was also compared by microscopic observation. Inoculation with G. mosseae gave higher plant yields than that with G. versiforme, and the two fungi responded differently in infection rate to available phosphorus level. Root infection rate of mycorrhizal maize colonized by G. mosseae decreased markedly with increasing P level, and there was very poor development of the extraradical mycelium at the highest rate of P addition. In contrast, G. versiforme showed greater tolerance to increasing P level. Elemental analysis showed that phosphorus, copper and zinc concentrations in the external mycelium differed between the two fungi and were much higher than those in the host plant.Differences in the morphology of the two fungi were also observed.

  12. Arbuscular mycorrhizal colonization, plant chemistry, and aboveground herbivory on Senecio jacobaea

    Science.gov (United States)

    Reidinger, Stefan; Eschen, René; Gange, Alan C.; Finch, Paul; Bezemer, T. Martijn

    2012-01-01

    Arbuscular mycorrhizal fungi (AMF) can affect insect herbivores by changing plant growth and chemistry. However, many factors can influence the symbiotic relationship between plant and fungus, potentially obscuring experimental treatments and ecosystem impacts. In a field experiment, we assessed AMF colonization levels of individual ragwort ( Senecio jacobaea) plants growing in grassland plots that were originally sown with 15 or 4 plant species, or were unsown. We measured the concentrations of carbon, nitrogen and pyrrolizidine alkaloids (PAs), and assessed the presence of aboveground insect herbivores on the sampled plants. Total AMF colonization and colonization by arbuscules was lower in plots sown with 15 species than in plots sown with 4 species and unsown plots. AMF colonization was positively related to the cover of oxeye daisy ( Leucanthemum vulgare) and a positive relationship between colonization by arbuscules and the occurrence of a specialist seed-feeding fly ( Pegohylemyia seneciella) was found. The occurrence of stem-boring, leaf-mining and sap-sucking insects was not affected by AMF colonization. Total PA concentrations were negatively related to colonization levels by vesicles, but did not differ among the sowing treatments. No single factor explained the observed differences in AMF colonization among the sowing treatments or insect herbivore occurrence on S. jacobaea. However, correlations across the treatments suggest that some of the variation was due to the abundance of one plant species, which is known to stimulate AMF colonization of neighbouring plants, while AMF colonization was related to the occurrence of a specialist insect herbivore. Our results thus illustrate that in natural systems, the ecosystem impact of AMF through their influence on the occurrence of specialist insects can be recognised, but they also highlight the confounding effect of neighbouring plant species identity. Hence, our results emphasise the importance of field

  13. Experimental warming decreases arbuscular mycorrhizal fungal colonization in prairie plants along a Mediterranean climate gradient

    Science.gov (United States)

    Johnson, Bart R.; Bohannan, Brendan; Pfeifer-Meister, Laurel; Mueller, Rebecca; Bridgham, Scott D.

    2016-01-01

    Background: Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding climate change effects on AMF, and the resulting plant responses, is crucial for predicting ecosystem responses at regional and global scales. We investigated how the effects of climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Methods: We used a combination of a greenhouse experiment and a manipulative climate change experiment embedded within a Mediterranean climate gradient in the Pacific Northwest, USA to examine this question. Structural equation modeling (SEM) was used to determine the direct and indirect effects of experimental warming on AMF colonization. Results: Warming directly decreased AMF colonization across plant species and across the climate gradient of the study region. Other positive and negative indirect effects of warming, mediated by soil water availability, soil nutrient availability, and vegetation dynamics, canceled each other out. Discussion: A warming-induced decrease in AMF colonization would likely have substantial consequences for plant communities and ecosystem function. Moreover, predicted increases in more intense droughts and heavier rains for this region could shift the balance among indirect causal pathways, and either exacerbate or mitigate the negative, direct effect of increased temperature on AMF colonization. PMID:27280074

  14. Arbuscular mycorrhizal colonization in field-collected terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns (Osmundaceae, Gleicheniaceae, Plagiogyriaceae, Cyatheaceae).

    Science.gov (United States)

    Ogura-Tsujita, Yuki; Hirayama, Yumiko; Sakoda, Aki; Suzuki, Ayako; Ebihara, Atsushi; Morita, Nana; Imaichi, Ryoko

    2016-02-01

    To determine the mycorrhizal status of pteridophyte gametophytes in diverse taxa, the mycorrhizal colonization of wild gametophytes was investigated in terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns, i.e., one species of Osmundaceae (Osmunda banksiifolia), two species of Gleicheniaceae (Diplopterygium glaucum, Dicranopteris linearis), and four species of Cyatheales including tree ferns (Plagiogyriaceae: Plagiogyria japonica, Plagiogyria euphlebia; Cyatheaceae: Cyathea podophylla, Cyathea lepifera). Microscopic observations revealed that 58 to 97% of gametophytes in all species were colonized with arbuscular mycorrhizal (AM) fungi. Fungal colonization was limited to the multilayered midrib (cushion) tissue in all gametophytes examined. Molecular identification using fungal SSU rDNA sequences indicated that the AM fungi in gametophytes primarily belonged to the Glomeraceae, but also included the Claroideoglomeraceae, Gigasporaceae, Acaulosporaceae, and Archaeosporales. This study provides the first evidence for AM fungal colonization of wild gametophytes in the Plagiogyriaceae and Cyatheaceae. Taxonomically divergent photosynthetic gametophytes are similarly colonized by AM fungi, suggesting that mycorrhizal associations with AM fungi could widely occur in terrestrial pteridophyte gametophytes.

  15. Does wheat genetically modified for disease resistance affect root-colonizing pseudomonads and arbuscular mycorrhizal fungi?

    Directory of Open Access Journals (Sweden)

    Joana Beatrice Meyer

    Full Text Available This study aimed to evaluate the impact of genetically modified (GM wheat with introduced pm3b mildew resistance transgene, on two types of root-colonizing microorganisms, namely pseudomonads and arbuscular mycorrhizal fungi (AMF. Our investigations were carried out in field trials over three field seasons and at two locations. Serial dilution in selective King's B medium and microscopy were used to assess the abundance of cultivable pseudomonads and AMF, respectively. We developed a denaturing gradient gel electrophoresis (DGGE method to characterize the diversity of the pqqC gene, which is involved in Pseudomonas phosphate solubilization. A major result was that in the first field season Pseudomonas abundances and diversity on roots of GM pm3b lines, but also on non-GM sister lines were different from those of the parental lines and conventional wheat cultivars. This indicates a strong effect of the procedures by which these plants were created, as GM and sister lines were generated via tissue cultures and propagated in the greenhouse. Moreover, Pseudomonas population sizes and DGGE profiles varied considerably between individual GM lines with different genomic locations of the pm3b transgene. At individual time points, differences in Pseudomonas and AMF accumulation between GM and control lines were detected, but they were not consistent and much less pronounced than differences detected between young and old plants, different conventional wheat cultivars or at different locations and field seasons. Thus, we conclude that impacts of GM wheat on plant-beneficial root-colonizing microorganisms are minor and not of ecological importance. The cultivation-independent pqqC-DGGE approach proved to be a useful tool for monitoring the dynamics of Pseudomonas populations in a wheat field and even sensitive enough for detecting population responses to altered plant physiology.

  16. Experimental warming decreases arbuscular mycorrhizal fungal colonization in prairie plants along a Mediterranean climate gradient

    OpenAIRE

    Wilson, Hannah; Johnson, Bart R.; Bohannan, Brendan; Pfeifer-Meister, Laurel; Mueller, Rebecca; Bridgham, Scott D.

    2016-01-01

    Background: Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding climate change effects on AMF, and the resulting plant responses, is crucial for predicting ecosystem responses at regional and global scales. We investigated how the effects of climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Methods: We used a combination of a greenhouse experiment and a manipulati...

  17. Metabolic activity of Glomus intraradices in Arum- and Paris-type arbuscular mycorrhizal colonization

    NARCIS (Netherlands)

    van Aarle, IM; Cavagnaro, TR; Smith, SE; Dickson, S

    2005-01-01

    Colonization of two plant species by Glomus intraradices was studied to investigate the two morphological types (Arum and Paris), their symbiotic interfaces and metabolic activities. Root pieces and sections were stained to observe the colonization and metabolic activity of all mycorrhizal structure

  18. Effect of arbuscular mycorrhizal colonization and two levels of compost supply on nutrient uptake and flowering of pelargonium plants.

    Science.gov (United States)

    Perner, Henrike; Schwarz, Dietmar; Bruns, Christian; Mäder, Paul; George, Eckhard

    2007-07-01

    Two challenges frequently encountered in the production of ornamental plants in organic horticulture are: (1) the rate of mineralization of phosphorus (P) and nitrogen (N) from organic fertilizers can be too slow to meet the high nutrient demand of young plants, and (2) the exclusive use of peat as a substrate for pot-based plant culture is discouraged in organic production systems. In this situation, the use of beneficial soil microorganisms in combination with high quality compost substrates can contribute to adequate plant growth and flower development. In this study, we examined possible alternatives to highly soluble fertilizers and pure peat substrates using pelargonium (Pelargonium peltatum L'Her.) as a test plant. Plants were grown on a peat-based substrate with two rates of compost addition and with and without arbuscular mycorrhizal (AM) fungi. Inoculation with three different commercial AM inocula resulted in colonization rates of up to 36% of the total root length, whereas non-inoculated plants remained free of root colonization. Increasing the rate of compost addition increased shoot dry weight and shoot nutrient concentrations, but the supply of compost did not always completely meet plant nutrient demand. Mycorrhizal colonization increased the number of buds and flowers, as well as shoot P and potassium (K) concentrations, but did not significantly affect shoot dry matter or shoot N concentration. We conclude that addition of compost in combination with mycorrhizal inoculation can improve nutrient status and flower development of plants grown on peat-based substrates.

  19. Depletion of soil mineral N by roots of ¤Cucumis sativus¤ L. colonized or not by arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Johansen, A.

    1999-01-01

    Two experiments were conducted where Cucumis sativus were grown in uncompartmented pots either alone or in symbiosis with Glomus intraradices Schenck and Smith (Experiment 1) or Glomus sp. (Experiment 2) in order to investigate if root colonization by arbuscular mycorrhizal (AM) fungi has an effect...

  20. Local and distal effects of arbuscular mycorrhizal colonization on direct pathway Pi uptake and root growth in Medicago truncatula

    DEFF Research Database (Denmark)

    Watts-Williams, Stephanie J.; Jakobsen, Iver; Cavagnaro, Timothy R.;

    2015-01-01

    Two pathways exist for plant Pi uptake from soil: via root epidermal cells (direct pathway) or via associations with arbuscular mycorrhizal (AM) fungi, and the two pathways interact in a complex manner. This study investigated distal and local effects of AM colonization on direct root Pi uptake...... fungi, but with no functional mycorrhizal pathway for Pi uptake, was included to better understand effects of AM colonization per se. Colonization by AM fungi decreased expression of direct Pi transporter genes locally, but not distally in the wild type. In mtpt4 mutant plants, direct Pi transporter...... genes and the Pi starvation-induced gene Mt4 were more highly expressed than in wild-type roots. In wild-type plants, less Pi was taken up via the direct pathway by non-colonized roots when the other root half was colonized by AM fungi, compared with non-mycorrhizal plants. Colonization by AM fungi...

  1. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    B. Knegt; J. Jansa; O. Franken; D.J.P. Engelmoer; G.D.A. Werner; H. Bücking; E.T. Kiers

    2014-01-01

    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  2. Spore population, colonization, species diversity and factors influencing the association of arbuscular mycorrhizal fungi with litchi trees in India.

    Science.gov (United States)

    Kumar, Vinod; Kumar, Rajesh; Kumar, Ajit; Anal, Dubedi

    2016-01-01

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) in association with litchi (Litchi chinensis Sonn.) trees were studied during 2012-2013, where orchard soil had high pH (7.42-9.53) and salinity (0.07- 0.39 dSm(-1)). A total of 105 rhizospheric soil and root samples were collected considering variables like location, age of tree, cultivar and production management. Results showed that spore count was in the range of 1-22 g(-1) soil. All the examined root segments had colonization of AMF, which ranged between 3.3 to 90.0%. AMF community comprised of Glomus mosseae, G. intaradices, G. constricta, G. coronatum, G. fasciculatum, G. albidum, G. hoi, G. multicauli, Acaulospora scrobiculata, A. laevis, Rhizophagus litchi and Entrophosphora infrequens. Higher spore density and AMF colonization were observed at medium level (13-28 kg ha(-1)) of available phosphorus that decreased ('r' = -0.21 for spore density, -0.48 for root colonization) with increasing soil phosphorus. While nitrogen did not influence the AMF association, a weak negative linear relationship with AMF colonization ('r' = -0.30) was apparent in the medium level (112-200 kg ha(-1)) of potash. Micronutrients (Zn, Fe, Cu, Mn and B) did not affect spore density (zero or a very weak linear correlation) but influenced root colonization ('r' = -0.53 to -0.44), the effect being more prominent above critical limits. Nutritionally sufficient, irrigated litchi orchards had greater spore count (46% samples having 5-22 spores g(-1) soil) and colonization (> 50% in 37.4% roots examined) than nutrient deficient, non-irrigated orchards, indicating essentiality of a threshold nutrients and moisture regime for the association. AMF symbiosis was influenced by cultivar (greater in 'China'), but tree age was not correlated to mycorrhizal association. A consortium of native species coupled with the understanding of nutrient effects on AMF would be useful for field application in litchi. PMID:26930865

  3. Effect of biosolids-derived triclosan and triclocarban on the colonization of plant roots by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Prosser, R S; Lissemore, L; Shahmohamadloo, R S; Sibley, P K

    2015-03-01

    Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with the majority of crop plants. AMF provide plants with nutrients (e.g., P), modulate the effect of metal and pathogen exposure, and increase tolerance to moisture stress. The benefits of AMF to plant growth make them important to the development of sustainable agriculture. The land application of biosolids is becoming an increasingly common practice in sustainable agriculture, as a source of nutrients. However, biosolids have been found to contain numerous pharmaceutical and personal care products including antimicrobial chemicals such as triclosan and triclocarban. The potential risks that these two compounds may pose to plant-AMF interactions are poorly understood. The current study investigated whether biosolids-derived triclosan and triclocarban affect the colonization of the roots of lettuce and corn plants by AMF. Plants were grown in soil amended with biosolids that contained increasing concentrations of triclosan (0 to 307 μg/g dw) or triclocarban (0 to 304 μg/g dw). A relationship between the concentration of triclosan or triclocarban and colonization of plants roots by AMF was not observed. The presence of biosolids did not have a significant (p>0.05) effect on percent colonization of corn roots but had a significant, positive effect (ptriclocarban did not inhibit the colonization of crop plant roots by AMF. PMID:25497682

  4. Effect of biosolids-derived triclosan and triclocarban on the colonization of plant roots by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Prosser, R S; Lissemore, L; Shahmohamadloo, R S; Sibley, P K

    2015-03-01

    Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with the majority of crop plants. AMF provide plants with nutrients (e.g., P), modulate the effect of metal and pathogen exposure, and increase tolerance to moisture stress. The benefits of AMF to plant growth make them important to the development of sustainable agriculture. The land application of biosolids is becoming an increasingly common practice in sustainable agriculture, as a source of nutrients. However, biosolids have been found to contain numerous pharmaceutical and personal care products including antimicrobial chemicals such as triclosan and triclocarban. The potential risks that these two compounds may pose to plant-AMF interactions are poorly understood. The current study investigated whether biosolids-derived triclosan and triclocarban affect the colonization of the roots of lettuce and corn plants by AMF. Plants were grown in soil amended with biosolids that contained increasing concentrations of triclosan (0 to 307 μg/g dw) or triclocarban (0 to 304 μg/g dw). A relationship between the concentration of triclosan or triclocarban and colonization of plants roots by AMF was not observed. The presence of biosolids did not have a significant (p>0.05) effect on percent colonization of corn roots but had a significant, positive effect (proots. Biosolids-derived triclosan and triclocarban did not inhibit the colonization of crop plant roots by AMF.

  5. Arbuscular mycorrhizal fungal colonization of Glycyrrhiza glabra roots enhances plant biomass, phosphorus uptake and concentration of root secondary metabolites

    Institute of Scientific and Technical Information of China (English)

    HongLing LIU; Yong TAN; Monika NELL; Karin ZITTER-EGLSEER; Chris WAWSCRAH; Brigitte KOPP; ShaoMing WANG; Johannes NOVAK

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi penetrate the cortical cells of the roots of vascular plants, and are widely distributed in soil. The formation of these symbiotic bodies accelerates the absorption and utilization of min-eral elements, enhances plant resistance to stress, boosts the growth of plants, and increases the survival rate of transplanted seedlings. We studied the effects of various arbuscular mycorrhizae fungi on the growth and devel-opment of licorice (Glycyrrhiza glabra). Several species of AM, such as Glomus mosseae, Glomus intraradices, and a mixture of fungi (G. mosseae, G. intraradices, G. cladoideum, G. microagregatum, G. caledonium and G. etunica-tum) were used in our study. Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi, plant dry biomass, phosphorus concentration and concentration of secondary metabolites. We estab-lished two cloned strains of licorice, clone 3 (C3) and clone 6 (C6) to exclude the effect of genotypic variations. Our results showed that the AM fungi could in fact increase the leaf and root biomass, as well as the phosphorus con-centration in each clone. Furthermore, AM fungi significantly increased the yield of certain secondary metabolites in clone 3. Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants. There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.

  6. General microflora, arbuscular mycorrhizal colonization and occurrence of endophytes in the rhizosphere of two age groups of Ginkgo biloba L.of Indian Central Himalaya

    OpenAIRE

    Kumar, Ajay; Singh, Shipra; Pandey, Anita

    2009-01-01

    The populations of the general microflora (bacteria, actinomycetes and fungi) in the rhizosphere and their corresponding non-rhizosphere soil samples of Ginkgo biloba L. of two age groups (Group A, 60 years-old trees) growing under a temperate location of Indian Himalayan Region (IHR) have been determined. Observations were also made for the diversity, distribution and colonization of arbuscular mycorrhizal (AM) fungi and occurrence of endophytes in roots of G. biloba. The population of gener...

  7. Ectomycorrhizal and arbuscular mycorrhizal colonization of Alnus acuminata from Calilegua National Park (Argentina).

    Science.gov (United States)

    Becerra, Alejandra; Zak, Marcelo R; Horton, Thomas R; Micolini, Jorge

    2005-11-01

    The objective of this study was to determine patterns of ectomycorrhizas (ECM) and arbuscular mycorrhizas (AM) colonization associated with Alnus acuminata (Andean alder), in relation to soil parameters (electrical conductivity, field H(2)O holding capacity, pH, available P, organic matter, and total N) at two different seasons (autumn and spring). The study was conducted in natural forests of A. acuminata situated in Calilegua National Park (Jujuy, Argentina). Nine ECM morphotypes were found on A. acuminata roots. The ECM colonization was affected by seasonality and associated positively with field H(2)O holding capacity, pH, and total N and negatively associated with organic matter. Two morphotypes (Russula alnijorullensis and Tomentella sp. 3) showed significant differences between seasons. Positive and negative correlations were found between five morphotypes (Alnirhiza silkacea, Lactarius omphaliformis, Tomentella sp. 1, Tomentella sp. 3, and Lactarius sp.) and soil parameters (total N, pH, and P). A significant negative correlation was found between field H(2)O holding capacity and organic matter with AM colonization. Results of this study provide evidence that ECM and AM colonization of A. acuminata can be affected by some soil chemical edaphic parameters and indicate that some ECM morphotypes are sensitive to changes in seasonality and soil parameters. PMID:16034621

  8. Influence of arbuscular mycorrhizal colonization on whole-plant respiration and thermal acclimation of tropical tree seedlings.

    Science.gov (United States)

    Fahey, Catherine; Winter, Klaus; Slot, Martijn; Kitajima, Kaoru

    2016-02-01

    Symbiotic arbuscular mycorrhizal fungi (AMF) are ubiquitous in tropical forests. AMF play a role in the forest carbon cycle because they can increase nutrient acquisition and biomass of host plants, but also incur a carbon cost to the plant. Through their interactions with their host plants they have the potential to affect how plants respond to environmental perturbation such as global warming. Our objective was to experimentally determine how plant respiration rates and responses to warmer environment are affected by AMF colonization in seedlings of five tropical tree species at the whole plant level. We evaluated the interaction between AMF colonization and temperature on plant respiration against four possible outcomes; acclimation does or does not occur regardless of AMF, or AMF can increase or decrease respiratory acclimation. Seedlings were inoculated with AMF spores or sterilized inoculum and grown at ambient or elevated nighttime temperature. We measured whole plant and belowground respiration rates, as well as plant growth and biomass allocation. There was an overall increase in whole plant, root, and shoot respiration rate with AMF colonization, whereas temperature acclimation varied among species, showing support for three of the four possible responses. The influence of AMF colonization on growth and allocation also varied among plant species. This study shows that the effect of AMF colonization on acclimation differs among plant species. Given the cosmopolitan nature of AMF and the importance of plant acclimation for predicting climate feedbacks a better understanding of the patterns and mechanisms of acclimation is essential for improving predictions of how climate warming may influence vegetation feedbacks.

  9. Influence of arbuscular mycorrhizal colonization on whole-plant respiration and thermal acclimation of tropical tree seedlings.

    Science.gov (United States)

    Fahey, Catherine; Winter, Klaus; Slot, Martijn; Kitajima, Kaoru

    2016-02-01

    Symbiotic arbuscular mycorrhizal fungi (AMF) are ubiquitous in tropical forests. AMF play a role in the forest carbon cycle because they can increase nutrient acquisition and biomass of host plants, but also incur a carbon cost to the plant. Through their interactions with their host plants they have the potential to affect how plants respond to environmental perturbation such as global warming. Our objective was to experimentally determine how plant respiration rates and responses to warmer environment are affected by AMF colonization in seedlings of five tropical tree species at the whole plant level. We evaluated the interaction between AMF colonization and temperature on plant respiration against four possible outcomes; acclimation does or does not occur regardless of AMF, or AMF can increase or decrease respiratory acclimation. Seedlings were inoculated with AMF spores or sterilized inoculum and grown at ambient or elevated nighttime temperature. We measured whole plant and belowground respiration rates, as well as plant growth and biomass allocation. There was an overall increase in whole plant, root, and shoot respiration rate with AMF colonization, whereas temperature acclimation varied among species, showing support for three of the four possible responses. The influence of AMF colonization on growth and allocation also varied among plant species. This study shows that the effect of AMF colonization on acclimation differs among plant species. Given the cosmopolitan nature of AMF and the importance of plant acclimation for predicting climate feedbacks a better understanding of the patterns and mechanisms of acclimation is essential for improving predictions of how climate warming may influence vegetation feedbacks. PMID:26865973

  10. Arbuscular mycorrhizal colonization in black poplar roots after defoliation by a non-native and a native insect

    Directory of Open Access Journals (Sweden)

    Zampieri E

    2016-08-01

    Full Text Available A major goal in ecology is to understand how interactions among organisms influence ecosystem services. This work compares the effects of two Lepidoptera defoliators, one non-native (Hyphantria cunea and one native (Lymantria dispar to Europe, on the colonization of black poplar (the Populus nigra clone “Jean Pourtet” roots by an arbuscular mycorrhizal (AM symbiotic fungus (Funneliformis mosseae in a pot experiment. The effects of defoliation have also been assessed on the expression of fungal and plant genes playing a role during symbiosis. Both control and defoliated poplars have shown a low level of mycorrhization. Additionally, neither the non-native nor the native insect seem to strongly affect the AM colonization, at least at the time of observation (eight days from the end of the defoliation. Concerning the gene expression analysis, our results suggest that defoliation does not influence neither the expression of genes coding for a fungal and a plant phosphate transporter nor that of a gene coding for a fungal ATPase, and that there were no differences between defoliation carried out by the non-native and the native insect.

  11. Arbuscular Mycorrhizal Colonization Enhanced Early Growth of Mallotus paniculatus and Albizia saman under Nursery Conditions in East Kalimantan, Indonesia

    Directory of Open Access Journals (Sweden)

    Dewi Wulandari

    2014-01-01

    Full Text Available Forest over logging, forest fire, forest conversion, and opencast mining have promoted deforestation in Indonesia, and reforestation is needed immediately. However, reforestation is limited by low seedling quality and production, and slow seedling growth in nurseries. Native tropical tree and fast-growing species, Mallotus paniculatus and Albizia saman, are potential to promote the first rotation of reforestation. Arbuscular mycorrhizal (AM fungi are known to promote nutrient uptake and plant growth. We examined the effects of two native AM fungi, Gigaspora decipiens and Glomus clarum, on the growth of M. paniculatus and A. saman seedlings under nursery conditions. At harvest, after six months, we determined AM colonization, shoot dry weight, and shoot N and P concentration. Approximately 90% and 50% of M. paniculatus and A. saman roots, respectively, were colonized by AM fungi, without any difference between the inoculation treatments. G. decipiens and G. clarum increased shoot height, leaf number, shoot dry weight, and shoot N and P uptake of both species. A positive correlation was observed between N and P uptake and shoot dry weight. These results suggest that AM fungi are effective in accelerating nutrient uptake and plant growth, which will, in turn, promote reforestation and sustainable forest timber production.

  12. Influence of silver and titanium nanoparticles on arbuscular mycorrhizal colonization and accumulation of radiocaesium in Helianthus annuus

    Energy Technology Data Exchange (ETDEWEB)

    Dubchak, S.; Ogar, A.; Mietelski, J. W.; Turnau, K.

    2010-07-01

    The influence of albacore's mycorrhizal fungus on {sup 1}34Cs uptake by Helianthus annuus was studied in a pilot study under growth chamber conditions. Mycorrhizal plants took up five times more {sup 1}34Cs (up to 250,000 Bq kg{sup -}1 dry weight) than non mycorrhizal plants. Silver and titanium nanoparticles, supplied into the surface soil layer decreased both the mycorrhizal colonization and Cs uptake by mycorrhizal plants. The application of activated carbon attenuated the effect of nanoparticles and increased {sup 1}34Cs uptake in the presence of mycorrhizal fungi (up to 400,000 Bq kg{sup -}1 dry weight). The results underline the possible application of phyto remediation techniques based on mycorrhizas assisted plants in decontamination of both radionuclides and nanoparticles. (Author) 27 refs.

  13. Arbuscular mycorrhizal colonization in maize genotypes grown under contrasted P-regimes in a long-term field experiment

    OpenAIRE

    Campos-Soriano, Lidia; Bach, Marcel; Arnal, Didier; Souche, Gerard; Hinsinger, Philippe; San Segundo, Blanca

    2014-01-01

    Most terrestrial flowering plants have the ability to establish symbiotic associations with arbuscular mycorrhizal (AM) fungi. The fungus improves the uptake of water and mineral nutrients in the host plant, mainly phosphorus and nitrogen, in exchange of photoassimilates. AM symbiosis not only promotes plant growth through facilitation of nutrient uptake, but it might also protect the plant from abiotic and/or biotic stresses. The benefits received by the AM symbiosis vary depending on the ho...

  14. Seasonal dynamics in arbuscular mycorrhizal fungal colonization and spore numbers in the rhizosphere of dactylis glomerata l. and trifolium repens L

    International Nuclear Information System (INIS)

    The seasonal dynamics in the colonization of the rhizosphere of orchardgrass (Dactylis glomerata L.) and white clover (Trifolium repens L.) pastures by arbuscular mycorrhizal (AM) fungi and the production of spores in an artifical Japanese grassland was investigated over 12 months (between December 2001 and December 2002). The results showed that the AM fungal colonization fluctuated seasonally in the rhizosphere of both pastures. The total AM fungal colonization of the two pastures decreased during winter, then increased from March to June as the pastures grew, but slightly decreased again in July and August, and again followed an increase in September. There was significant difference of the colonization by arbuscules and vesicles between the two pastures ( p <0.05). Besides, the vesicular colonization of orchardgrass was higher than that of white clover, but the opposite trend was observed for arbuscular colonization. Similarly, the numbers of AM fungal spores in the pastures varied throughout the year, decreasing from spring to summer, then slowly increasing in late summer, reaching peak levels in winter. There is significant correlation between the frequency of spores in the rhizosphere soil and both soil temperature and pH. (author)

  15. Gold Nanomaterial Uptake from Soil Is Not Increased by Arbuscular Mycorrhizal Colonization of Solanum Lycopersicum (Tomato)

    OpenAIRE

    Jonathan D. Judy; Jason K. Kirby; Mike J McLaughlin; Timothy Cavagnaro; Bertsch, Paul M.

    2016-01-01

    Bioaccumulation of engineered nanomaterials (ENMs) by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components present in the soil might fundamentally alter the potential of plant bioaccumulation of ENMs is unclear. Here, we used two genotypes of Solanum lycopersicum (tomato), reduced mycorrhizal colonizati...

  16. Striga seed-germination activity of root exudates and compounds present in stems of Striga host and nonhost (trap crop) plants is reduced due to root colonization by arbuscular mycorrhizal fungi.

    NARCIS (Netherlands)

    Lendzemo, V.W.; Kuyper, T.W.; Vierheilig, H.

    2009-01-01

    Root colonization by arbuscular mycorrhizal (AM) fungi reduces stimulation of seed germination of the plant parasite Striga (Orobanchaceae). This reduction can affect not only host plants for Striga, resulting in a lower parasite incidence, but also false hosts or trap crops, which induce suicidal S

  17. Communities, populations and individuals of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Rosendahl, Søren

    2008-01-01

    Arbuscular mycorrhizal fungi in the phylum Glomeromycota are found globally in most vegetation types, where they form a mutualistic symbiosis with plant roots. Despite their wide distribution, only relatively few species are described. The taxonomy is based on morphological characters of the asexual resting spores, but molecular approaches to community ecology have revealed a considerable unknown diversity from colonized roots. Although the lack of genetic recombination is not unique in the fungal kingdom, arbuscular mycorrhizal fungi are probably ancient asexuals. The long asexual evolution of the fungi has resulted in considerable genetic diversity within morphologically recognizable species, and challenges our concepts of individuals and populations. This review critically examines the concepts of species, communities, populations and individuals of arbuscular mycorrhizal fungi.

  18. Striga seed-germination activity of root exudates and compounds present in stems of Striga host and nonhost (trap crop) plants is reduced due to root colonization by arbuscular mycorrhizal fungi.

    OpenAIRE

    Lendzemo, V.W.; Kuyper, T. W.; Vierheilig, H.

    2009-01-01

    Root colonization by arbuscular mycorrhizal (AM) fungi reduces stimulation of seed germination of the plant parasite Striga (Orobanchaceae). This reduction can affect not only host plants for Striga, resulting in a lower parasite incidence, but also false hosts or trap crops, which induce suicidal Striga seed germination, thereby diminishing their effectiveness. In order to better understand these AM-induced effects, we tested the influence of root colonization by different AM fungi on the se...

  19. Phosphorus and nitrogen regulate arbuscular mycorrhizal symbiosis in Petunia hybrida.

    Directory of Open Access Journals (Sweden)

    Eva Nouri

    Full Text Available Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phosphorus supply has previously been shown to exert strong inhibition of arbuscular mycorrhizal development. Here, we address to what extent inhibition by phosphorus is influenced by other nutritional pathways in the interaction between Petunia hybrida and R. irregularis. We show that phosphorus and nitrogen are the major nutritional determinants of the interaction. Interestingly, the symbiosis-promoting effect of nitrogen starvation dominantly overruled the suppressive effect of high phosphorus nutrition onto arbuscular mycorrhiza, suggesting that plants promote the symbiosis as long as they are limited by one of the two major nutrients. Our results also show that in a given pair of symbiotic partners (Petunia hybrida and R. irregularis, the entire range from mutually symbiotic to parasitic can be observed depending on the nutritional conditions. Taken together, these results reveal complex nutritional feedback mechanisms in the control of root colonization by arbuscular mycorrhizal fungi.

  20. Arbuscular mycorrhizal fungi affect phytophagous insect specialism

    OpenAIRE

    Gange, Alan; Stagg, P.G.; Ward, L. K.

    2002-01-01

    The majority of phytophagous insects eat very few plant species, yet the ecological and evolutionary forces that have driven such specialism are not entirely understood. The hypothesis that arbuscular mycorrhizal (AM) fungi can determine phytophagous insect specialism, through differential effects on insect growth, was tested using examples from the British flora. In the UK, plant families and species in the family Lamiaceae that are strongly mycorrhizal have higher proportions of specialist ...

  1. Molecular diversity and distribution of indigenous arbuscular mycorrhizal communities colonizing roots of two different winter cover crops in response to their root proliferation.

    Science.gov (United States)

    Higo, Masao; Isobe, Katsunori; Miyazawa, Yusuke; Matsuda, Yukiya; Drijber, Rhae A; Torigoe, Yoichi

    2016-02-01

    A clear understanding of how crop root proliferation affects the distribution of the spore abundance of arbuscular mycorrhizal fungi (AMF) and the composition of AMF communities in agricultural fields is imperative to identify the potential roles of AMF in winter cover crop rotational systems. Toward this goal, we conducted a field trial using wheat (Triticum aestivum L.) or red clover (Trifolium pratense L.) grown during the winter season. We conducted a molecular analysis to compare the diversity and distribution of AMF communities in roots and spore abundance in soil cropped with wheat and red clover. The AMF spore abundance, AMF root colonization, and abundance of root length were investigated at three different distances from winter crops (0 cm, 7.5 cm, and 15 cm), and differences in these variables were found between the two crops. The distribution of specific AMF communities and variables responded to the two winter cover crops. The majority of Glomerales phylotypes were common to the roots of both winter cover crops, but Gigaspora phylotypes in Gigasporales were found only in red clover roots. These results also demonstrated that the diversity of the AMF colonizing the roots did not significantly change with the three distances from the crop within each rotation but was strongly influenced by the host crop identity. The distribution of specific AMF phylotypes responded to the presence of wheat and red clover roots, indicating that the host crop identity was much more important than the proliferation of crop roots in determining the diversity of the AMF communities.

  2. Molecular diversity and distribution of indigenous arbuscular mycorrhizal communities colonizing roots of two different winter cover crops in response to their root proliferation.

    Science.gov (United States)

    Higo, Masao; Isobe, Katsunori; Miyazawa, Yusuke; Matsuda, Yukiya; Drijber, Rhae A; Torigoe, Yoichi

    2016-02-01

    A clear understanding of how crop root proliferation affects the distribution of the spore abundance of arbuscular mycorrhizal fungi (AMF) and the composition of AMF communities in agricultural fields is imperative to identify the potential roles of AMF in winter cover crop rotational systems. Toward this goal, we conducted a field trial using wheat (Triticum aestivum L.) or red clover (Trifolium pratense L.) grown during the winter season. We conducted a molecular analysis to compare the diversity and distribution of AMF communities in roots and spore abundance in soil cropped with wheat and red clover. The AMF spore abundance, AMF root colonization, and abundance of root length were investigated at three different distances from winter crops (0 cm, 7.5 cm, and 15 cm), and differences in these variables were found between the two crops. The distribution of specific AMF communities and variables responded to the two winter cover crops. The majority of Glomerales phylotypes were common to the roots of both winter cover crops, but Gigaspora phylotypes in Gigasporales were found only in red clover roots. These results also demonstrated that the diversity of the AMF colonizing the roots did not significantly change with the three distances from the crop within each rotation but was strongly influenced by the host crop identity. The distribution of specific AMF phylotypes responded to the presence of wheat and red clover roots, indicating that the host crop identity was much more important than the proliferation of crop roots in determining the diversity of the AMF communities. PMID:26832664

  3. Dry matter and root colonization of plants by indigenous arbuscular mycorrhizal fungi with physical fractions of dry olive mill residue inoculated with saprophytic fungi

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, E.; Sampredro, I.; Diaz, R.; Garcia-Sanchez, M.; Siles, J. A.; Ocampo, J. A.; Garcia-Romera, I.

    2010-07-01

    We studied the influence of indigenous arbuscular mycorrhizal (AM) and saprobe fungi on the phytotoxicity of the physical fractions of dry olive mill residue (DOR). The physical extractions of DOR gave an aqueous (ADOR) and an exhausted (SDOR) fraction with less phytotoxicity for tomato than the original samples. The indigenous AM were able to decrease the phytotoxicity of SDOR inoculated with Trametes versicolor and Pycnoporus cinnabarinus on tomato. However, incubation of ADOR with both saprophytic fungi did not decrease its phytotoxicity in presence of the indigenous AM fungi. The percentage of root length colonized by indigenous AM strongly decreased in presence of DOR, around 80% of decrease at dose of 25 g kg-1of DOR, but the level of mycorrhization was higher in presence of ADOR or SDOR (38% and 44% of decrease respectively at the same dose). There were no relationships between the effects of the physical fractions of DOR incubated with the saprobe fungi on AM colonization and on plant dry weight of tomato. Our results suggest that the phytotoxicity of the olive residues can be eliminated by the combination of physical extraction and by saprobe fungal inoculation and the use of this agrowaste as organic amendment in agricultural soil may be possible. (Author) 33 refs.

  4. Arbuscular mycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters Colonización micorrícico arbuscular de Alnus acuminata Kunth en el noroeste argentino en relación a la estacionalidad y a los parámetros edáficos

    OpenAIRE

    Alejandra Gabriela Becerra; Nilda Marta Arrigo; Norberto Bartoloni; Laura Susana Domínguez; María Noelia Cofré

    2007-01-01

    The objective of this study was to determine patterns of arbuscular mycorrhizal (AM) colonization of Alnus acuminata Kunth at two natural forests in relation to soil parameters at two different seasons (autumn and spring). The soil parameters studied were field capacity, pH, electrical conductivity, available P, total N and organic matter. The percentage of AM colonization was estimated and correlated to soil properties and to two different seasons. The results indicate that the percentage of...

  5. Arbuscular mycorrhizal fungal diversity, root colonization, and soil alkaline phosphatase activity in response to maize-wheat rotation and no-tillage in North China.

    Science.gov (United States)

    Hu, Junli; Yang, Anna; Zhu, Anning; Wang, Junhua; Dai, Jue; Wong, Ming Hung; Lin, Xiangui

    2015-07-01

    Monitoring the effects of no-tillage (NT) in comparison with conventional tillage (CT) on soil microbes could improve our understanding of soil biochemical processes and thus help us to develop sound management strategies. The objective of this study was to compare the species composition and ecological function of soil arbuscular mycorrhizal (AM) fungi during the growth and rotation of crops under NT and CT. From late June 2009 to early June 2010, 32 topsoil (0-15 cm) samples from four individual plots per treatment (CT and NT) were collected at both the jointing and maturation stages of maize (Zea mays L.) and wheat (Triticum aestivum L.) from a long-term experimental field that was established in an Aquic Inceptisol in North China in June 2006. The AM fungal spores were isolated and identified and then used to calculate species diversity indices, including the Shannon- Wiener index (H'), Evenness (E), and Simpson's index (D). The root mycorrhizal colonization and soil alkaline phosphatase activity were also determined. A total of 34 species of AM fungi within nine genera were recorded. Compared with NT, CT negatively affected the soil AM fungal community at the maize sowing stage, leading to decreases in the average diversity indices (from 2.12, 0.79, and 0.82 to 1.79, 0.72, and 0.74 for H', E, and D, respectively), root mycorrhizal colonization (from 28% to 20%), soil alkaline phosphatase activity (from 0.24 to 0.19 mg/g/24 h) and available phosphorus concentration (from 17.4 to 10.5 mg/kg) at the maize jointing stage. However, reductions in diversity indices of H', E, and D were restored to 2.20, 0.81, and 0.84, respectively, at the maize maturation stage. CT should affect the community again at the wheat sowing stage; however, a similar restoration in the species diversity of AM fungi was completed before the wheat jointing stage, and the highest Jaccard index (0.800) for similarity in the species composition of soil AM fungi between CT and NT was recorded at

  6. Consequences of inoculation with native arbuscular mycorrhizal fungi for root colonization and survival of Artemisia tridentata ssp. wyomingensis seedlings after transplanting.

    Science.gov (United States)

    Davidson, Bill E; Novak, Stephen J; Serpe, Marcelo D

    2016-08-01

    In arid environments, the propagule density of arbuscular mycorrhizal fungi (AMF) may limit the extent of the plant-AMF symbiosis. Inoculation of seedlings with AMF could alleviate this problem, but the success of this practice largely depends on the ability of the inoculum to multiply and colonize the growing root system after transplanting. These phenomena were investigated in Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) seedlings inoculated with native AMF. Seedlings were first grown in a greenhouse in soil without AMF (non-inoculated seedlings) or with AMF (inoculated seedlings). In spring and fall, 3-month-old seedlings were transplanted outdoors to 24-L pots containing soil from a sagebrush habitat (spring and fall mesocosm experiments) or to a recently burned sagebrush habitat (spring and fall field experiments). Five or 8 months after transplanting, colonization was about twofold higher in inoculated than non-inoculated seedlings, except for the spring field experiment. In the mesocosm experiments, inoculation increased survival during the summer by 24 % (p = 0.011). In the field experiments, increased AMF colonization was associated with increases in survival during cold and dry periods; 1 year after transplanting, survival of inoculated seedlings was 27 % higher than that of non-inoculated ones (p AMF increased survival, we analyzed water use efficiency (WUE) based on foliar (13)C/(12)C isotope ratios (δ (13)C). A positive correlation between AMF colonization and δ (13)C values was observed in the spring mesocosm experiment. In contrast, inoculation did not affect the δ (13)C values of fall transplanted seedlings that were collected the subsequent spring. The effectiveness of AMF inoculation on enhancing colonization and reducing seedling mortality varied among the different experiments, but average effects were estimated by meta-analyses. Several months after transplanting, average AMF colonization was in proportion 84

  7. EFFECT OF ARBUSCULAR MYCORRHIZAL COLONIZATION ON EARLY GROWTH AND NUTRIENT CONTENT OF TWO PEAT­ SWAMP FOREST TREE SPECIES SEEDLINGS, Calophyllum hosei AND Ploiarium alternifolium

    Directory of Open Access Journals (Sweden)

    Maman Turjaman

    2006-03-01

    Full Text Available Tropical peat-swamp forests are one of  the largest near-surface reserves of terrestrial organic carbon,  but rnany peat-swamp forest tree species decreased due over-exploitation, forest fire and conversion of natural forests into agricultural lands. Among those species are slow-growing Calophyllum  hoseiand Ploiarium  alternifolium, two species are good for construction of boats, furniture, house building and considerable attention from pharmacological viewpoint for human healthly. This study was aimed at understanding the effects of arbuscular mycorrhizal (AM fungi on early growth of  C. hosei and P.alternifoliumunder greenhouse condition. Seedlings of C. hosei and P.alternifoliumwere inoculated with AM fungi: Glomus clarum and Glomus aggregatum ,or uninoculated under greenhouse condition during 6 months. AM colonization,   plant growth,  survival rate and  nutrient  content  (P, Zn  and B were measured. The percentage of C. hoseiand P.alternifolium ranged from 27-32% and 18-19%,  respectively. Both inoculated seedling species had greater plant  height, diameter, leaf number, shoot and root dry weight than control  seedlings.   Nutrient  content  of  inoculated  plants  were increased with AM colonization- Survival rates of  inoculated plants were higher (100%  than those of  control plants (67%. The results suggested that inoculation of AM fungi could improve the early growth of C. hoseiand P.alternifolium grown in tropical peat-swamp forest therefore  this finding has greater potential impact if this innovative technology applied in field scales which are socially acceptable, commercially profitable and environmentally friendly.

  8. Impact of PAHs on the development of the arbuscular mycorrhizal fungus, G. Intraradices, on the colonization of chicory and carrot grown in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Verdin, A.; Lounes-Hadj Sahraoui, A.; Fontaine, J.; Grandmougin-Ferjani, A.; Durand, R. [Universite du Littoral-Cote d' Opale, Lab. de Mycologie/Phytopathologie/Environnement, 62 - Calais (France)

    2005-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent pollutants found in many environments as result of the incomplete combustion of organic matter, and some of them are of great environmental concern due to their highly cytotoxic, genotoxic and carcinogenic properties for mammals. PAHs are thermodynamically stable and recalcitrant to microbial degradation, due to their aromatic nature and low aqueous solubility. Ecologically and economically speaking, plants have tremendous potential for bio-remediation of PAH-contaminated soils. The effect of plant roots on the dissipation of organic pollutants has mainly been attributed to an increase in microbial population and selection of specialized microbial communities in the rhizosphere, and also by improving physical and chemical soil conditions. Arbuscular mycorrhizal (AM) fungi living in symbiosis with plant roots play an essential role in plant nutrition and stress tolerance. AM plants are known to be involved in the biodegradation of pollutants such as PAHs. The role of AM fungi concerns two aspects: the improvement of the establishment and development of plants on polluted soil and the enhancement of PAHs degradation levels. AM colonization of different plant species is negatively affected when the plants are grown in contaminated soils. Nevertheless the AM colonization was shown to enhance plant survival and growth. Objectives of this work was to study the impact of PAHs on the development of G. intraradices and on the colonization of chicory (Cichorium intybus L.) and carrot (Daucus carota L.) roots transformed by Agrobacterium rhizogenes. Monoxenous root cultures have obvious advantages over traditional systems. This technique provides unique visualization of extra-radical fungus development and also allows an important production of extra-radical hyphae, spores and colonized roots free of any other microorganisms. These aspects are important to evaluate direct impact of PAHs on AM fungal

  9. Impact of PAHs on the development of the arbuscular mycorrhizal fungus, G. Intraradices, on the colonization of chicory and carrot grown in vitro

    International Nuclear Information System (INIS)

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent pollutants found in many environments as result of the incomplete combustion of organic matter, and some of them are of great environmental concern due to their highly cytotoxic, genotoxic and carcinogenic properties for mammals. PAHs are thermodynamically stable and recalcitrant to microbial degradation, due to their aromatic nature and low aqueous solubility. Ecologically and economically speaking, plants have tremendous potential for bio-remediation of PAH-contaminated soils. The effect of plant roots on the dissipation of organic pollutants has mainly been attributed to an increase in microbial population and selection of specialized microbial communities in the rhizosphere, and also by improving physical and chemical soil conditions. Arbuscular mycorrhizal (AM) fungi living in symbiosis with plant roots play an essential role in plant nutrition and stress tolerance. AM plants are known to be involved in the biodegradation of pollutants such as PAHs. The role of AM fungi concerns two aspects: the improvement of the establishment and development of plants on polluted soil and the enhancement of PAHs degradation levels. AM colonization of different plant species is negatively affected when the plants are grown in contaminated soils. Nevertheless the AM colonization was shown to enhance plant survival and growth. Objectives of this work was to study the impact of PAHs on the development of G. intraradices and on the colonization of chicory (Cichorium intybus L.) and carrot (Daucus carota L.) roots transformed by Agrobacterium rhizogenes. Monoxenous root cultures have obvious advantages over traditional systems. This technique provides unique visualization of extra-radical fungus development and also allows an important production of extra-radical hyphae, spores and colonized roots free of any other microorganisms. These aspects are important to evaluate direct impact of PAHs on AM fungal

  10. Enhanced Tomato Disease Resistance Primed by Arbuscular Mycorrhizal Fungus

    Directory of Open Access Journals (Sweden)

    Yuanyuan eSong

    2015-09-01

    Full Text Available Roots of most terrestrial plants form symbiotic associations (mycorrhiza with soil- borne arbuscular mycorrhizal fungi (AMF. Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill. early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL and lipoxygenase (LOX in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related (PR proteins, PR1, PR2 and PR3, as well as defense-related genes LOX, AOC and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT plant, a jasmonate (JA biosynthesis mutant (spr2, and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for

  11. Enhanced tomato disease resistance primed by arbuscular mycorrhizal fungus.

    Science.gov (United States)

    Song, Yuanyuan; Chen, Dongmei; Lu, Kai; Sun, Zhongxiang; Zeng, Rensen

    2015-01-01

    Roots of most terrestrial plants form symbiotic associations (mycorrhiza) with soil- borne arbuscular mycorrhizal fungi (AMF). Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill.) early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL) and lipoxygenase (LOX) in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related proteins, PR1, PR2, and PR3, as well as defense-related genes LOX, AOC, and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT) plant, a jasmonate (JA) biosynthesis mutant (spr2), and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for mycorrhiza

  12. Arbuscular Mycorrhizal Fungal Associations in Biofuel Cropping Systems

    Science.gov (United States)

    Murray, K.

    2012-12-01

    Arbuscular mycorrhizal fungi (AMF) are soil microorganisms that play an important role in delivering nutrients to plant roots via mutualistic symbiotic relationships. AMF root colonization was compared between four different biofuel cropping systems in an effort to learn more about the factors that control colonization. The four biofuel systems sampled were corn, switchgrass, prairie, and fertilized prairie. We hypothesized that prairie systems would have the highest levels of AMF colonization and that fertilization would result in lower AMF colonization rates. Roots were sampled from each system in early June and mid-July. Soil P and pH were also measured. In contrast to our hypothesis, corn systems had 70-80% colonization and the unfertilized prairie system had ~35% (P=0.001) in June. In July, all systems saw an increase in colonization rate, but corn roots still had significantly more AMF colonization than unfertilized prairie (P=0.001). AMF colonization in the unfertilized prairie system increased ~55% from June to July. In contrast to previous work, AMF colonization rates were highest in systems with the greatest availability on P and N (corn systems). These results indicate that seasonal differences in root growth were more influential to AMF root colonization than soil nutrient availability.

  13. DELLA proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Floss, Daniela S; Levy, Julien G; Lévesque-Tremblay, Véronique; Pumplin, Nathan; Harrison, Maria J

    2013-12-17

    Most flowering plants are able to form endosymbioses with arbuscular mycorrhizal fungi. In this mutualistic association, the fungus colonizes the root cortex and establishes elaborately branched hyphae, called arbuscules, within the cortical cells. Arbuscule development requires the cellular reorganization of both symbionts, and the resulting symbiotic interface functions in nutrient exchange. A plant symbiosis signaling pathway controls the development of the symbiosis. Several components of the pathway have been identified, but transcriptional regulators that control downstream pathways for arbuscule formation are still unknown. Here we show that DELLA proteins, which are repressors of gibberellic acid (GA) signaling and function at the nexus of several signaling pathways, are required for arbuscule formation. Arbuscule formation is severely impaired in a Medicago truncatula Mtdella1/Mtdella2 double mutant; GA treatment of wild-type roots phenocopies the della double mutant, and a dominant DELLA protein (della1-Δ18) enables arbuscule formation in the presence of GA. Ectopic expression of della1-Δ18 suggests that DELLA activity in the vascular tissue and endodermis is sufficient to enable arbuscule formation in the inner cortical cells. In addition, expression of della1-Δ18 restores arbuscule formation in the symbiosis signaling pathway mutant cyclops/ipd3, indicating an intersection between DELLA and symbiosis signaling for arbuscule formation. GA signaling also influences arbuscule formation in monocots, and a Green Revolution wheat variety carrying dominant DELLA alleles shows enhanced colonization but a limited growth response to arbuscular mycorrhizal symbiosis.

  14. Arbuscular mycorrhizal associations in Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands of Northern Ethiopia.

    NARCIS (Netherlands)

    Emiru Birhane, E.B.; Kuyper, T.W.; Sterck, F.J.; Bongers, F.

    2010-01-01

    This study assessed the arbuscular mycorrhizal (AM) status of Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands in relation to season, management and soil depth in Ethiopia. We studied 43 woody species in 52 plots in three areas. All woody species were colonized by AM fungi,

  15. Arbuscular mycorrhizal inoculation of peanut in low-fertile tropical soil. II. Alleviation of drought stress

    NARCIS (Netherlands)

    Quilambo, OA; Weissenhorn, I.; Doddema, H; Kuiper, PJC; Stulen, I.

    2005-01-01

    The effect of drought stress and inoculation with an indigenous Mozambican and a commercial arbuscular mycorrhizal (AM) inoculant on root colonization and plant growth and yield was studied in two peanut (Arachis hypogaea L.) cultivars-a traditional, low-yielding Mozambican landrace (Local) and a mo

  16. The scion/rootstock genotypes and habitats affect arbuscular mycorrhizal fungal community in citrus

    NARCIS (Netherlands)

    Song, Fang; Pan, Zhiyong; Bai, Fuxi; An, Jianyong; Liu, Jihong; Guo, Wenwu; Bisseling, Ton; Deng, Xiuxin; Xiao, Shunyuan

    2015-01-01

    Citrus roots have rare root hairs and thus heavily depend on arbuscular mycorrhizal fungi (AMF) for mineral nutrient uptake. However, the AMF community structure of citrus is largely unknown. By using 454-pyrosequencing of 18S rRNA gene fragment, we investigated the genetic diversity of AMF colon

  17. Effect of different arbuscular mycorrhizal fungal isolates on growth and arsenic accumulation in Plantago lanceolata L

    International Nuclear Information System (INIS)

    The role of indigenous and non-indigenous arbuscular mycorrhizal fungi (AMF) on As uptake by Plantago lanceolata L. growing on substrate originating from mine waste rich in As was assessed in a pot experiment. P. lanceolata inoculated with AMF had higher shoot and root biomass and lower concentrations of As in roots than the non-inoculated plants. There were significant differences in As concentration and uptake between different AMF isolates. Inoculation with the indigenous isolate resulted in increased transfer of As from roots to shoots; AMF from non-polluted area apparently restricted plants from absorbing As to the tissue; and plants inoculated with an AMF isolate from Zn–Pb waste showed strong As retainment within the roots. Staining with dithizone indicated that AMF might be actively involved in As accumulation. The mycorrhizal colonization affected also the concentration of Cd and Zn in roots and Pb concentration, both in shoots and roots. - Highlights: ► The role of arbuscular mycorrhizal fungi (AMF) in As uptake was studied. ► Growth of Plantago lanceolata was significantly enhanced by mycorrhizal inoculation. ► Arsenic concentration and uptake significantly depended on the AMF isolate. ► Arbuscular mycorrhizal fungi may be useful for bioremediation of As contaminated wastes. - Effect of arbuscular mycorrhizal fungi on As uptake by Plantago lanceolata strongly depends on the origin of fungal isolates.

  18. The arbuscular mycorrhizal status of poplar clones selected for phytoremediation of soils contaminated with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, T.; Radimszky, L.; Nemeth, T. [Research Inst. for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Budapest (Hungary)

    2005-04-01

    The aim of this work was to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) species in fine-roots of poplar clones. Roots of 7 poplar clones were sampled from a 1-year-old trial established at an industrial site strongly polluted with heavy metals at Balatonfuezfoe, Hungary. The poplar clones have shown variable degrees of colonization by AMF, suggesting differential host susceptibility or mycorrhizal dependency. After outplanting the percentage of poplar survival was strongly correlated with the frequency of AMF infection. Two clones that survived at the lowest ratio after outplanting had not been colonized by AMF in contrast to those which survived to a much higher extent. (orig.)

  19. The effect of different soil properties on arbuscular mycorrhizal colonization of peanuts, sorghum and maize Diferentes propriedades do solo na colonização micorrízica arbuscular de amendoim, sorgo e milho

    Directory of Open Access Journals (Sweden)

    Rosilaine Carrenho

    2007-09-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF are important for plant growth since they increase mineral influx. However, symbiosis efficiency is affected by many environmental factors. This study evaluated the effects of different treatments (+/- phosphorus; +/- liming; +/- organic matter; field, sandy or clayey soil textures on root colonization (RC of peanuts, sorghum and maize. The combination of these resulted in seventy-two treatments. The 2×2×2×3×3 factorial experiment was laid out in a randomized design. All data were subjected to variance analysis and the means were compared (Tukey at PFungos micorrízicos arbusculares (FMA são importantes para o crescimento das plantas, pois aumentam o influxo de minerais. Porém, a eficiência simbiótica é afetada por muitos fatores ambientais. Este estudo avaliou os efeitos de diferentes tratamentos (+/- fósforo; +/- calcário; +/- matéria orgânica; texturas de solo arenosa, argilosa e de campo sobre a colonização radical (CR de amendoim, sorgo e milho. Da combinação destes fatores resultaram 72 tratamentos. O experimento fatorial foi do tipo 2×2×2×3×3, com amostragem inteiramente ao acaso. Os dados foram submetidos à análise de variância e ao teste de Tukey (P< 0,05. Três meses após a germinação das sementes, as raízes foram coletadas para avaliação das percentagens de CR. Os resultados mostraram que a textura do solo e a calagem foram os fatores que mais influenciaram a CR em milho, sorgo e amendoim. Diferenças significativas também foram observadas entre os fitobiontes. Matéria orgânica teve influência pouco significativa sobre a CR enquanto adição de fósforo não ocasionou variação.

  20. Communities, populations and individuals of arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Rosendahl, Søren

    2008-01-01

    Arbuscular mycorrhizal fungi in the phylum Glomeromycota are found globally in most vegetation types, where they form a mutualistic symbiosis with plant roots. Despite their wide distribution, only relatively few species are described. The taxonomy is based on morphological characters...

  1. COLONIZAÇÃO E DENSIDADE DE ESPOROS DE FUNGOS MICORRÍZICOS EM DOIS SOLOS DO CERRADO SOB DIFERENTES SISTEMAS DE MANEJO COLONIZATION AND SPORE DENSITY OF ARBUSCULAR MYCORRHIZAL FUNGI IN TWO CERRADO SOILS IN DIFFERENT TILLAGE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Helder Barbosa Paulino

    2007-09-01

    Full Text Available

    O presente estudo teve como objetivo avaliar a colonização micorrízica e a densidade de esporos de fungos micorrízicos arbusculares (FMA, bem como os efeitos de diferentes sistemas de manejo em duas classes de solo (Neossolo Quartzarênico e Latossolo Vermelho. O estudo foi conduzido em áreas agrícolas do entorno do Parque Nacional das Emas, Estado de Goiás, onde se determinaram a densidade de esporos de FMA e a colonização micorrízica de raízes, nos diferentes sistemas de manejo. Áreas sob cultivo de gramíneas apresentaram maiores colonização micorrízica e densidade de esporos de FMA, nos dois solos estudados, relativamente à área cultivada com soja. Verificou-se pequeno efeito dos sistemas de manejo do solo nas características avaliadas, no entanto, os resultados obtidos mostram alterações na população de FMA, com um aumento na densidade de esporos que refletiu na colonização micorrízica nas áreas agrícolas, em relação às áreas de referência.

    PALAVRAS-CHAVE: Indicador biológico; solos arenosos; conservação do solo; qualidade de solo.

    The objective of this study was the evaluation of root micorrhyzal colonization and the spore density of arbuscular mycorrhizal fungi (AMF, as well as the effects of tillage systems in two soil classes (Entisol and Oxisol. The study was carried out in farms around the ";Parque Nacional das Emas";, Goiás State, Brazil, where density of AMF spores and mycorrhizal colonization of roots in the different tillage systems were determined. Areas cultivated with grasses presented larger mycorrhizal colonization and density of AMF spores in both soils as compared with the soybean cropped area. Small effect of the tillage systems was verified in regard to evaluated characteristics. However, the results showed

  2. When do arbuscular mycorrhizal fungi protect plant roots from pathogens?

    Science.gov (United States)

    Sikes, Benjamin A

    2010-06-01

    Arbuscular mycorrhizal (AM) fungi are mainly thought to facilitate phosphorus uptake in plants, but they can also perform several other functions that are equally beneficial. Our recent study sheds light on the factors determining one such function, enhanced plant protection from root pathogens. Root infection by the fungal pathogen Fusarium oxysporum was determined by both plant susceptibility and the ability of an AM fungal partner to suppress the pathogen. The non-susceptible plant species (Allium cepa) had limited F. oxysporum infection even without AM fungi. In contrast, the susceptible plant species (Setaria glauca) was heavily infected and only AM fungi in the family Glomeraceae limited pathogen abundance. Plant susceptibility to pathogens was likely determined by contrasting root architectures between plants, with the simple rooted plant (A. cepa) presenting fewer sites for infection.AM fungal colonization, however, was not limited in the same way in part because plants with fewer, simple roots are more mycorrhizal dependent. Protection only by Glomus species also indicates that whatever the mechanism(s) of this function, it responds to AM fungal families differently. While poor at pathogen protection, AM fungal species in the family Gigasporaceae most benefited the growth of the simple rooted plant species. Our research indicates that plant trait differences, such as root architecture can determine how important each mycorrhizal function is to plant growth but the ability to provide these functions differs among AM fungi. PMID:20400855

  3. Biodegradation of polycyclic aromatic hydrocarbons by arbuscular mycorrhizal leek plants

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A.; Dalpe, Y. [Agriculture Canada, Ottawa, ON (Canada). Grain and Oilseeds Branch

    2005-07-01

    A study was conducted to examine the response of arbuscular mycorrhizal fungi (AMF) on the degradation of polycyclic aromatic hydrocarbon (PAH), nutrient uptake, and leek growth under greenhouse conditions. This experiment included 3 mycorrhizal treatments, 2 microorganism treatments, 2 PAH chemicals, and 4 concentrations of PAHs. Plant growth was greatly reduced by the addition of anthracene or phenanthrene in soil, whereas mycorrhizal inoculation not only increased plant growth, but also enhanced uptake of nitrogen and phosphorus. PAH concentrations in soil was lowered through the inoculation of two different strains of the species G. intraradices and G. versiforme. In 12 weeks of pot cultures, anthracene and phenanthrene concentrations decreased for all 3 PAH levels tested. However, the reduced amount of phenanthrene in soil was greater than that of anthracene. The addition of a soil microorganism extract into pot cultures accelerated the PAH degradation. The inoculation of AMF in a hydrocarbon contaminated soil was shown to enhance PAHs soil decontamination. It was concluded that a soil colonized with AMF can not only improve plant growth but can also stimulate soil microflora abundance and diversity. AMF may therefore directly influence PAH soil decontamination through plant growth enhancement.

  4. Spore communities of arbuscular mycorrhizal fungi and mycorrhizal associations in different ecosystems, south Australia

    Directory of Open Access Journals (Sweden)

    Z. I. Antoniolli

    2002-09-01

    Full Text Available Communities of arbuscular mycorrhizal fungi (AMF were surveyed in different South Australian ecosystems. The soil was wet-sieved for spore extraction, followed by the determination of presence and abundance of AMF species as well as the percentage of root colonization. Mycorrhizal associations were common and there was substantial fungal diversity in different ecosystems. Spores were most abundant in the permanent pasture system and less abundant under continuous wheat. The incidence of mycorrhizal associations in different plant species and the occurrence of Arum and Paris type colonization generally conformed with previous information. Spores of seventeen AMF were verified throughout seasonal changes in 1996 and 1997 in the permanent pasture and on four host species (Lolium perenne, Plantago lanceolata, Sorghum sp. and Trifolium subterraneum , set up with the same soils under greenhouse conditions. Glomus mosseae was the dominant spore type at all sampling times and in all trap cultures. Mycorrhizal diversity was significantly affected by different sampling times in trap cultures but not in field-collected soil. P. lanceolata, Sorghum sp. and T. subterraneum as hosts for trap cultures showed no differences in richness and diversity of AMF spores that developed in association with their roots. Abundance and diversity were lowest, however, in association with L. perenne , particularly in December 1996. Results show that the combination of spore identification from field-collected soil and trap cultures is essential to study population and diversity of AMF. The study provides baseline data for ongoing monitoring of mycorrhizal populations using conventional methods and material for the determination of the symbiotic effectiveness of AMF key members.

  5. Chasing the structures of small molecules in arbuscular mycorrhizal signaling.

    Science.gov (United States)

    Bucher, Marcel; Wegmüller, Sarah; Drissner, David

    2009-08-01

    The arbuscular mycorrhiza (AM) is a symbiosis between most terrestrial plants and fungi of the ancient phylum Glomeromycota. AM improves the uptake of water and mineral nutrients, such as phosphorus (P) and nitrogen (N), of the host plant in exchange for photosynthetically fixed carbon. Successful colonization and a functional interaction between host plant and mycobiont are based upon exchange of signaling molecules at different stages of symbiosis development. Strigolactones, a novel class of plant hormones, are secreted by plant roots stimulating presymbiotic growth of AM fungi. Fungi release soluble signaling molecules, the enigmatic 'Myc factors', that activate early symbiotic root responses. Lysophosphatidylcholine is a lipophilic intraradical mycorrhizal signal triggering plant phosphate transporter gene expression late in AM development through a P-controlled transcriptional mechanism. This enables uptake of orthophosphate released from the AM fungus.

  6. Alterations of the Antioxidant Enzyme Activities are not General Characteristics of the Colonization Process by Arbuscular Mycorrhizal Fungi Alteraciones de las Actividades de Enzimas Antioxidantes no son Características Generales del Proceso de Colonización por Hongos Micorrízicos Arbusculares

    Directory of Open Access Journals (Sweden)

    Yakelin Rodríguez

    2012-09-01

    Full Text Available Antioxidant system is involved in arbuscular mycorrhizal symbiosis, but its role during the colonization process is still poorly understood. To gain new insights into the role of antioxidant system during root colonization by arbuscular mycorrhizal fungi, the activities of key antioxidant enzymes were evaluated in tomato (Solanum lycopersicum L. roots inoculated with six strains of different genera and species: two Glomus mosseae, Glomus cubense, Glomus intraradices, Glomus sp. and Acaulospora scrobiculata. Glomus cubense and A. scrobiculata strains reached the highest infectivity levels with maximum values of colonization frequency and intensity of 29-10.88% and 18-9.20%, respectively; G. mosseae strains showed an intermediate infectivity, both with 15% of colonization frequency and maximum intensities of 7.647.06%, respectively; while the infectivity levels of Glomus sp. and G. intraradices strains were the lowest with colonization frequency- 13% and intensities- 5.07 and 5.41, respectively. Some activity patterns of peroxidase, superoxide dismutase, and polyphenol oxidase enzymes were not specific for early or late colonization stages neither for the colonization level and type of strain. However, a unique superoxide dismutase-band presents at early colonization and the low level of guaiacol-peroxidase activity at later stages presents in all inoculated roots indicate that these antioxidant responses are independent of colonization degree and strain. Taking together, our data suggest that alterations of the antioxidant enzyme activities are not general characteristics of the colonization process by arbuscular mycorrhizal fungi, probably having the key role on those responses the specific feature of each strain rather than colonization per se.El sistema antioxidante está involucrado en la simbiosis micorrízico-arbuscular, pero su rol durante el proceso de colonización es aún escasamente comprendido. Para esclarecer el papel del sistema

  7. Epiparasitic plants specialized on arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Bidartondo, Martin I; Redecker, Dirk; Hijri, Isabelle; Wiemken, Andres; Bruns, Thomas D; Domínguez, Laura; Sérsic, Alicia; Leake, Jonathan R; Read, David J

    2002-09-26

    Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature.

  8. Enzymatic activities and arbuscular mycorrhizal colonization of Plantago lanceolata and Plantago major in a soil root zone under heavy metal stress.

    Science.gov (United States)

    Gucwa-Przepióra, Ewa; Nadgórska-Socha, Aleksandra; Fojcik, Barbara; Chmura, Damian

    2016-03-01

    The objectives of the present field study were to examine the soil enzyme activities in the soil root zones of Plantago lanceolata and Plantago major in different heavy metal contaminated stands. Moreover, the investigations concerned the intensity of root endophytic colonization and metal bioaccumulation in roots and shoots. The investigated Plantago species exhibited an excluder strategy, accumulating higher metal content in the roots than in the shoots. The heavy metal accumulation levels found in the two plantain species in this study were comparable to other plants suggested as phytostabilizers; therefore, the selected Plantago species may be applied in the phytostabilization of heavy metal contaminated areas. The lower level of soil enzymes (dehydrogenase, urease, acid, and alkaline phosphatase) as well as the higher bioavailability of metals in the root zone soil of the two plantain species were found in an area affected by smelting activity, where organic matter content in the soil was also the smallest. Mycorrhizal colonization on both species in the contaminated area was similar to colonization in non-contaminated stands. However, the lowest arbuscule occurrence and an absence of dark septate endophytes were found in the area affected by the smelting activity. It corresponded with the lowest plant cover observed in this stand. The assessment of enzyme activity, mycorrhizal colonization, and the chemical and physical properties of soils proved to be sensitive to differences between sites and between Plantago species. PMID:26531716

  9. Enzymatic activities and arbuscular mycorrhizal colonization of Plantago lanceolata and Plantago major in a soil root zone under heavy metal stress.

    Science.gov (United States)

    Gucwa-Przepióra, Ewa; Nadgórska-Socha, Aleksandra; Fojcik, Barbara; Chmura, Damian

    2016-03-01

    The objectives of the present field study were to examine the soil enzyme activities in the soil root zones of Plantago lanceolata and Plantago major in different heavy metal contaminated stands. Moreover, the investigations concerned the intensity of root endophytic colonization and metal bioaccumulation in roots and shoots. The investigated Plantago species exhibited an excluder strategy, accumulating higher metal content in the roots than in the shoots. The heavy metal accumulation levels found in the two plantain species in this study were comparable to other plants suggested as phytostabilizers; therefore, the selected Plantago species may be applied in the phytostabilization of heavy metal contaminated areas. The lower level of soil enzymes (dehydrogenase, urease, acid, and alkaline phosphatase) as well as the higher bioavailability of metals in the root zone soil of the two plantain species were found in an area affected by smelting activity, where organic matter content in the soil was also the smallest. Mycorrhizal colonization on both species in the contaminated area was similar to colonization in non-contaminated stands. However, the lowest arbuscule occurrence and an absence of dark septate endophytes were found in the area affected by the smelting activity. It corresponded with the lowest plant cover observed in this stand. The assessment of enzyme activity, mycorrhizal colonization, and the chemical and physical properties of soils proved to be sensitive to differences between sites and between Plantago species.

  10. Role of the arbuscular mycorrhizal symbiosis in tolerance response against Armillaria mellea in lavender

    Directory of Open Access Journals (Sweden)

    Cinta Calvet

    2015-09-01

    Full Text Available Lavender species form the arbuscular mycorrhizal symbiosis and are at the same time highly susceptible to white root rot. In an attempt to evaluate the response of mycorrhizal Lavandula angustifolia L. to Armillaria mellea (Vahl:Fr P. Kumm in a greenhouse experiment, plants were previously inoculated with an isolate of the arbuscular mycorrhizal fungus Rhizophagus irregularis (former Glomus intraradices BEG 72 and the influence of the pH growing medium on the plant-symbiont-pathogen interaction was tested in gnotobiotic autotrophic growth systems in which mycorrhizal inoculum was obtained from root organ cultures. After ten months growth dual-inoculated lavender plants grown in containers with a pasteurized substrate mixture produced a similar number of spikes than healthy plants and achieved equivalent plant diameter coverage. When the growing medium in the autotrophic systems was supplemented with calcium carbonate, the inoculation of lavender plantlets with R. irregularis at higher pH (7.0 and 8.5 media caused a significant decrease of A. mellea presence in plant roots, as detected by qPCR. Moreover, the observation of internal root mycorrhizal infection showed that the extent of mycorrhizal colonization increasedin plant rootsgrown at higher pH, indicating that tolerance to white root rot in lavender plants inoculated with R. irregularis could be associated to mycorrhizal establishment.

  11. Colonization of arbuscular mycorrhizal fungi and dark septate endophytes in Panax notoginseng%三七根中丛枝菌根真菌与深色有隔内生真菌侵染状况研究

    Institute of Scientific and Technical Information of China (English)

    张智慧; 陈迪; 赵丹丹; 金航; 李凌飞

    2011-01-01

    目的:对云南文山州3个三七主产区的三七根系进行调查,研究不同地点、不同生长年限、健康三七和根腐病三七根内从枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和深色有隔内生真菌(dark septate endophytes,DSE)的侵染状况.方法:利用碱解离、酸性品红染色法对144个三七根样进行显微观察.结果与结论:三七为典型的丛枝菌根植物.虽然3个样地间的AMF和DSE侵染率均没有显著差异,但三七根内AMF的总侵染率(6%~94%,平均51.79%)显著高于DSE的侵染率(0 ~71%,平均为2.76%);且三七根鲜重与AMF侵染率显著正相关,而与DSE侵染率无显著相关性,表明AMF对改善三七品质和提高三七产量具有比DSE更为重要的作用;此外,健康三七的AMF侵染率显著高于根腐病三七,表明AMF提高了三七的抗根腐病能力,因而在三七根腐病防治方面具有极大的潜力和广阔的前景.%Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) colonizing Panax notoginseng in three main producing areas in Wenshan Prefecture of Yunan province were investigated. Llie fungal colonization of 144 roots samples including healthy and rot roots of P. Notoginseng with different age were observed by means of acid fuchsin stain. Hie results showed that P. Notoginseng was the typical arbuscular mycorrhizal plant Although there was no significant difference in AMF and DSE colonization among three sites, the total colonization of AMF was significantly higher than that of DSE. Statistical analysis demonstrated that the fresh weight of P. Notoginseng root was positively significantly correlated with the colonization of AMF, but not with the colonization of DSE. These results suggest that AMF may play more important role than DSE in improving the yield and quality of P. Notoginseng. Furthermore, AMF colonization of healthy P. Notoginseng was higher than that of plant with root rot, which suggested that AMF could defend P

  12. Selection of Infective Arbuscular Mycorrhizal Fungal Isolates for Field Inoculation

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    Elisa Pellegrino

    2010-09-01

    Full Text Available Arbuscular mycorrhizal (AM fungi play a key role in host plant growth and health, nutrient and water uptake, plant community diversity and dynamics. AM fungi differ in their symbiotic performance, which is the result of the interaction of two fungal characters, infectivity and efficiency. Infectivity is the ability of a fungal isolate to establish rapidly an extensive mycorrhizal symbiosis and is correlated with pre-symbiotic steps of fungal life cycle, such as spore germination and hyphal growth. Here, different AM fungal isolates were tested, with the aim of selecting infective endophytes for field inoculation. Greenhouse and microcosm experiments were performed in order to assess the ability of 12 AM fungal isolates to produce spores, colonize host roots and to perform initial steps of symbiosis establishment, such as spore germination and hyphal growth. AM fungal spore production and root colonization were significantly different among AM fungal isolates. Spore and sporocarp densities ranged from 0.8 to 7.4 and from 0.6 to 2.0 per gram of soil, respectively, whereas root colonization ranged from 2.9 to 72.2%. Percentage of spore or sporocarp germination ranged from 5.8 to 53.3% and hyphal length from 4.7 to 79.8 mm. The ordination analysis (Redundancy Analysis, RDA showed that environmental factors explained about 60% of the whole variance and their effect on fungal infectivity variables was significant (P = 0.002. The biplot clearly showed that variables which might be used to detect infective AM fungal isolates were hyphal length and root colonization. Such analysis may allow the detection of the best parameters to select efficient AM fungal isolates to be used in agriculture.

  13. The arbuscular mycorrhizal symbiosis influences sulfur starvation responses of Medicago truncatula.

    Science.gov (United States)

    Sieh, Daniela; Watanabe, Mutsumi; Devers, Emanuel A; Brueckner, Franziska; Hoefgen, Rainer; Krajinski, Franziska

    2013-01-01

    Arbuscular mycorrhizal (AM) symbiosis is a mutualistic interaction that occurs between the large majority of vascular plants and fungi of the phylum Glomeromycota. In addition to other nutrients, sulfur compounds are symbiotically transferred from AM fungus to host plants; however, the physiological importance of mycorrhizal-mediated sulfur for plant metabolism has not yet been determined. We applied different sulfur and phosphate fertilization treatments to Medicago truncatula and investigated whether mycorrhizal colonization influences leaf metabolite composition and the expression of sulfur starvation-related genes. The expression pattern of sulfur starvation-related genes indicated reduced sulfur starvation responses in mycorrhizal plants grown at 1 mM phosphate nutrition. Leaf metabolite concentrations clearly showed that phosphate stress has a greater impact than sulfur stress on plant metabolism, with no demand for sulfur at strong phosphate starvation. However, when phosphate nutrition is high enough, mycorrhizal colonization reduces sulfur stress responses, probably as a result of symbiotic sulfur uptake. Mycorrhizal colonization is able to reduce sulfur starvation responses in M. truncatula when the plant's phosphate status is high enough that sulfur starvation is of physiological importance. This clearly shows the impact of mycorrhizal sulfur transfer on plant metabolism.

  14. Effect of inoculation with arbuscular mycorrhizal fungi on the degradation of DEHP in soil

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-guang; LIN Xian-gui; YIN Rui; HOU Yan-lin

    2004-01-01

    The effect of inoculation with arbuscular mycorrhiza(AM) fungi(Acaulospora lavis) on the degradation of di(2-ethylhexyl) phthalate(DEHP) in soil was studies. Cowpea plants(Pigna sinensis) were used as host plants and grown in a specially designed rhizobox. The experimental results indicated that, both in sterile and non-sterile soil, mycorrhizal colonization rates were much higher in the mycorrhizal plants than in the non-mycorrhizal plants. Addition of 4 mg/kg DEHP slightly affected mycorrhizal colonization, but the addition of 100 mg/kg DEHP significantly decreased mycorrhizal colonization. DEHP degradation in the mycorrhizosphere(Ms) and hyphosphere(Hs), especially in the Hs, increased after inoculation with Acaulospora lavis. It is concluded that mycorrhizal hyphae play an important role in the plant uptake, degradation and translocation of DEHP. The mechanism might be attributed to increased numbers of bacteria and actinomycetes and activity of dehydrogenase, urease and acid phosphatase in the Ms and Hs by mycorrhizal fungi.

  15. Mycorrhizal colonization across hydrologic gradients in restored and reference freshwater wetlands

    Science.gov (United States)

    Bauer, C.R.; Kellogg, C.H.; Bridgham, S.D.; Lamberti, G.A.

    2003-01-01

    Arbuscular mycorrhizae, which are plant root-fungal symbioses, are common associates of vascular plants. Such relationships, however, are thought to be rare in wetland plant roots, although several recent studies suggest that arbuscular mycorrhizae may be important in wetland ecosystems. Our objectives were to determine (1) the level of arbuscular mycorrhizal colonization of plant roots in three freshwater marshes and (2) the effect of restoration status, hydrologic zone, and plant species identity on mycorrhizal colonization. We quantified the percentage of plant roots colonized by mycorrhizal fungi in one reference and two restored freshwater marshes in northern Indiana, USA during summer 1999. Roots were collected from soil cores taken around dominant plant species present in each of three hydrologic zones and then stained for microscopic examination of mycorrhizal colonization. Mycorrhizae were present in each wetland, in all hydrologic zones and in all sampled plants, including Carex and Scirpus species previously thought to be non-mycorrhizal. Both restored and reference wetlands had moderate levels of mycorrhizal colonization, but no clear trends in colonization were seen with hydrologic zone, which has been hypothesized to regulate the formation of mycorrhizae in wetlands. Mycorrhizal colonization levels in the roots of individual species ranged from 3 to 90% and were particularly large in members of the Poaceae (grass) family. Our results suggest that arbuscular mycorrhizae may be widely distributed across plant species and hydrologic zones in both restored and reference freshwater marshes. Thus, future research should examine the functional role of mycorrhizal fungi in freshwater wetlands. ?? 2003, The Society of Wetland Scientists.

  16. Linking root traits to nutrient foraging in arbuscular mycorrhizal trees in a temperate forest.

    Science.gov (United States)

    Eissenstat, David M; Kucharski, Joshua M; Zadworny, Marcin; Adams, Thomas S; Koide, Roger T

    2015-10-01

    The identification of plant functional traits that can be linked to ecosystem processes is of wide interest, especially for predicting vegetational responses to climate change. Root diameter of the finest absorptive roots may be one plant trait that has wide significance. Do species with relatively thick absorptive roots forage in nutrient-rich patches differently from species with relatively fine absorptive roots? We measured traits related to nutrient foraging (root morphology and architecture, root proliferation, and mycorrhizal colonization) across six coexisting arbuscular mycorrhizal (AM) temperate tree species with and without nutrient addition. Root traits such as root diameter and specific root length were highly correlated with root branching intensity, with thin-root species having higher branching intensity than thick-root species. In both fertilized and unfertilized soil, species with thin absorptive roots and high branching intensity showed much greater root length and mass proliferation but lower mycorrhizal colonization than species with thick absorptive roots. Across all species, fertilization led to increased root proliferation and reduced mycorrhizal colonization. These results suggest that thin-root species forage more by root proliferation, whereas thick-root species forage more by mycorrhizal fungi. In mineral nutrient-rich patches, AM trees seem to forage more by proliferating roots than by mycorrhizal fungi.

  17. Diversity of arbuscular mycorrhizal fungi in grassland spontaneously developed on area polluted by a fertilizer plant

    Energy Technology Data Exchange (ETDEWEB)

    Renker, C. [Institute of Ecology, Department of Environmental Sciences, University of Jena, Dornburger Str. 159, D-07743 Jena (Germany)]. E-mail: crenker@uni-leipzig.de; Blanke, V. [Institute of Ecology, Department of Environmental Sciences, University of Jena, Dornburger Str. 159, D-07743 Jena (Germany); Buscot, F. [Institute of Ecology, Department of Environmental Sciences, University of Jena, Dornburger Str. 159, D-07743 Jena (Germany)

    2005-05-01

    Mycorrhizal colonization and diversity of arbuscular mycorrhizal fungi (AMF) were analyzed in a calcareous grassland with residual phosphate contamination 10 years after the closure of a pollutant fertilizer plant in Thuringia (Germany). AMF were detected in 21 of 22 plant species analyzed. Mean mycorrhization levels reached up to 74.5% root length colonized. AMF diversity was analyzed based on 104 sequences of the internal transcribed spacer (ITS) of the ribosomal DNA. Phylogenetic analyses revealed a total of 6 species all belonging to the genus Glomus. There was no overlap between species detected as active mycorrhizas on roots (2 taxa) or as spores (4 taxa). Compared to the regional context, the diversity of AMF at our field site was reduced, which may reflect a residual disturbance effect. However, none of the detected species was exclusive to the polluted site as they are commonly found in the region. - Almost all plant species were mycorrhizal.

  18. Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups ...

  19. Arbuscular mycorrhizal fungus-promoted accumulation of two new triterpenoids in cucumber roots.

    Science.gov (United States)

    Akiyama, Kohki; Hayashi, Hideo

    2002-04-01

    Cucumber (Cucumis sativus L.) roots were analyzed by HPLC and TLC for their levels of secondary metabolites upon inoculation with the arbuscular mycorrhizal fungus, Glomus caledonium. Three compounds in EtOAc extracts from the mycorrhizal roots showed significant increases six weeks after inoculation. These compounds were isolated by column chromatography and determined to be two novel triterpenes, 2beta-hydroxybryonolic acid (2beta,3beta-dihydroxy-D:C-friedoolean-8-en-29-oic acid) and 3beta-bryoferulic acid [3beta-O-trans-ferulyl-D:C-friedooleana-7,9(11)-diene-29-oic acid], and the known triterpene, bryonolic acid, by spectroscopic methods. Time-course experiments showed that the levels of the three terpenoids in cucumber roots were significantly increased by the application of a 53-microm sieving from a soil inoculum of the arbuscular mycorrhizal fungus containing soil microbes but no mycorrhizal fungi, and that mycorrhizal colonization further promoted the terpenoid accumulation. Inoculation with Glomus mosseae also enhanced the accumulation of the triterpenes, whereas no accumulation was observed by inoculating with the fungal pathogen, Fusarium oxysporum f. sp. cucumerinum. 2Beta-hydroxybryonolic acid was also isolated from the roots of melon and watermelon. PMID:12036048

  20. Correlation between specific fine root length and mycorrhizal colonization of maize in different soil types

    Institute of Scientific and Technical Information of China (English)

    Wenke LIU

    2009-01-01

    A pot experiment was conducted in a glass-house to investigate the correlation between specific fine root length (SFRL) and root colonization (RC) of maize inoculated with six arbuscular mycorrhizal fungi (AMF) in three soil types. The results showed that six AMF associated with maize presented different abilities in RC and effects on SFRL. In addition, there was a significant correlation between SFRL and RC of arbuscular mycor-rhizal maize in Beijing soil (Cinnamon soil), but no significant correlation in Hubei soil (Brunisolic soil) and Guangdong soil (Red soil). It is concluded that mycor-rhizal colonization decreased the SFRL of maize, and the correlation between SFRL and RC of mycorrhizal maize depended on soil type.

  1. Spore density and root colonization by arbuscular mycorrhizal fungi in preserved or disturbed Araucaria angustifolia (Bert. O. Ktze. ecosystems Densidade de esporos e colonização radicular por fungos microrrízicos arbusculares em ecossistemas de Araucaria angustifolia (Bert. O. Ktze. preservados e impactados

    Directory of Open Access Journals (Sweden)

    Milene Moreira

    2006-08-01

    Full Text Available Araucaria angustifolia (Bert. O. Ktze., a native forest tree from Brazil, is under extinction risk. This tree depends on arbuscular mycorrhizal fungi for growth and development, especially in tropical low-P soils but, despite being a conifer, Araucaria does not form ectomycorrhiza, but only the arbuscular endomycorrhiza. This study aimed at surveying data on the spore density and root colonization (CR by arbuscular mycorrhizal fungi (AMF in Araucaria angustifolia forest ecosystems, in order to discriminate natural, implemented, and anthropic action-impacted ecosystems, by means of Canonical Discriminant Analysis (CDA. Three ecosystems representative of the Campos do Jordão (SP, Brazil region were selected: 1. a native forest (FN; 2. a replanted Araucaria forest (R; and 3. a replanted Araucaria forest, submitted to accidental fire (RF. Rhizosphere soil and roots were sampled in May and October, 2002, for root colonization, AMF identification, and spores counts. Root percent colonization rates at first collection date were relatively low and did not differ amongst ecosystems. At the second period, FN presented higher colonization than the other two areas, with much higher figures than during the first period, for all areas. Spore density was lower in FN than in the other areas. A total of 26 AMF species were identified. The percent root colonization and spore numbers were inversely related to each other in all ecosystems. CDA indicated that there is spatial distinction among the three ecosystems in regard to the evaluated parameters.A Araucaria angustifolia (Bert. O. Ktze. é uma espécie florestal nativa do Brasil e encontra-se ameaçada de extinção. É altamente dependente de fungos micorrízicos arbusculares para seu desenvolvimento, principalmente em solos com baixos teores de fósforo. Embora sendo uma conífera, esta árvore não forma ectomicorriza, mas sim a endomicorriza arbuscular. O presente estudo teve como objetivo levantar dados

  2. Systematic Identification, Evolution and Expression Analysis of the Zea mays PHT1 Gene Family Reveals Several New Members Involved in Root Colonization by Arbuscular Mycorrhizal Fungi

    Directory of Open Access Journals (Sweden)

    Fang Liu

    2016-06-01

    Full Text Available The Phosphate Transporter1 (PHT1 family of genes plays pivotal roles in the uptake of inorganic phosphate from soils. However, there is no comprehensive report on the PHT1 family in Zea mays based on the whole genome. In the present study, a total of 13 putative PHT1 genes (ZmPHT1;1 to 13 were identified in the inbred line B73 genome by bioinformatics methods. Then, their function was investigated by a yeast PHO84 mutant complementary experiment and qRT-PCR. Thirteen ZmPHT1 genes distributed on six chromosomes (1, 2, 5, 7, 8 and 10 were divided into two paralogues (Class A and Class B. ZmPHT1;1/ZmPHT1;9 and ZmPHT1;9/ZmPHT1;13 are produced from recent segmental duplication events. ZmPHT1;1/ZmPHT1;13 and ZmPHT1;8/ZmPHT1;10 are produced from early segmental duplication events. All 13 putative ZmPHT1s can completely or partly complement the yeast Pi-uptake mutant, and they were obviously induced in maize under low Pi conditions, except for ZmPHT1;1 (p < 0.01, indicating that the overwhelming majority of ZmPHT1 genes can respond to a low Pi condition. ZmPHT1;2, ZmPHT1;4, ZmPHT1;6, ZmPHT1;7, ZmPHT1;9 and ZmPHT1;11 were up-regulated by arbuscular mycorrhizal fungi (AMF, implying that these genes might participate in mediating Pi absorption and/or transport. Analysis of the promoters revealed that the MYCS and P1BS element are widely distributed on the region of different AMF-inducible ZmPHT1 promoters. In light of the above results, five of 13 ZmPHT1 genes were newly-identified AMF-inducible high-affinity phosphate transporters in the maize genome. Our results will lay a foundation for better understanding the PHT1 family evolution and the molecular mechanisms of inorganic phosphate transport under AMF inoculation.

  3. Uptake of Organic Phosphorus by Arbuscular Mycorrhizal Red Clover

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The capacities of two arbuscular mycorrhizal (AM) fungi, Glomus mosseae and Glomus versiforme, to mineralize added organic P were studied in a sterilized calcareous soil. Mycorrhizal (inoculated with either of the AM fungi) and non-mycorrhizal red clover (Trifolium pratense L.) plants were grown for eight weeks in pots with upper root, central hyphal and lower soil compartments. The hyphal and soil compartments received either organic P (as Na-phytate) or inorganic P (as KH2PO4) at the rate of 50 mg P kg-1. No P was added to the root compartments. Control pots received no added P. Yields were higher in mycorrhizal than in non-mycorrhizal clover. Mycorrhizal inoculation doubled shoot P concentration and more than doubled total P uptake of plants in P-amended soil, irrespective of the form of applied P. The mycorrhizal contribution to inorganic P uptake was 80% or 76% in plants inoculated with G. mosseae or G. versiforme, respectively.Corresponding values were 74% and 82% when Na-phytate was applied. In the root compartments of the mycorrhizal treatments, the proportion of root length infected, hyphal length density and phosphatase activity were all higher when organic P was applied than when inorganic P was added.

  4. Unravelling the influence of arbuscular mycorrhizal (AM colonization on arsenic tolerance in Medicago: Glomus mosseae is more effective than G. intraradices, associated with lower expression of root epidermal Pi transporter genes.

    Directory of Open Access Journals (Sweden)

    Helle Martha Christophersen

    2012-04-01

    Full Text Available We used medic (Medicago truncatula to investigate effects of inoculation with two arbuscular mycorrhizal (AM fungi and application of arsenate (AsV and phosphate (Pi on mechanisms underlying increased tolerance (in terms of growth of AM plants to AsV. We tested the hypotheses that 1 inoculation with AM fungi results in down-regulation of MtPht1;1 and MtPht1;2 genes (encoding high-affinity Pi- and AsV-uptake systems in the direct root epidermal pathway and up-regulation of the AM-induced MtPht1;4 (responsible for transfer of Pi from the arbuscular interface to cortical cells, and 2 these changes are involved in decreased As uptake relative to P uptake and hence increased As tolerance. We also measured expression of MtMT4, a Pi starvation-inducible gene, other genes encoding Pi-uptake systems (MtPht 1;5 and MtPht1;6 and arsenate reductase (MtACR and phytochelatin synthase (MtPCS, to gain insights into broader aspects of P transfers in AM plants and possible detoxification mechanisms.Medic responded slightly to AM colonization in terms of growth in the absence of As, but positively in P uptake. Both growth and P responses in AM plants were positive when As was applied, indicating As tolerance relative to non-mycorrhizal (NM plants. All AM plants showed high expression of MtPT4 and those inoculated with Glomus mosseae showed higher selectivity against As (shown by P/As molar ratios and much lower expression of MtPht1;1 (and to some extent MtPht1;2 than G. intraradices-inoculated or NM plants. Results are consistent with increased P/As selectivity in AM plants (particularly those inoculated with G. mosseae as a consequence of high P uptake but little or no As uptake via the AM pathway. However, the extent to which selectivity is dependent on down-regulation of direct Pi and AsV uptake through epidermal cells is still not clear. Marked up-regulation of a PCS gene and an ACR gene in AM plants may also be involved and require further investigatio

  5. Growth and extracellular phosphatase activity of arbuscular mycorrhizal hyphae as influenced by soil organic matter

    DEFF Research Database (Denmark)

    Joner, E.J.; Jakobsen, I.

    1995-01-01

    length density was twice as high in soil with added straw compared to the two other treatments. Mycorrhizal colonization resulted in lower activity of acid phosphatase in the HC for two out of three treatments. Alkaline phosphatase activity was only decreased by mycorrhiza in soil without organic matter...... additions. In soil with added clover alkaline phosphatase activity increased due to the presence of mycorrhizal hyphae. We suggest that mycorrhizas may influence the exudation of acid phosphatase by roots. Hyphae of G. invermaium did apparently not excrete extracellular phosphatases, but their presence may......Two experiments were set up to investigate the influence of soil organic matter on growth of arbuscular mycorrhizal (AM) hyphae and concurrent changes in soil inorganic P, organic P and phosphatase activity. A sandy loam soil was kept for 14 months under two regimes (outdoor where surplus...

  6. Arbuscular mycorrhizal fungi (Glomeromycota associated with roots of plants

    Directory of Open Access Journals (Sweden)

    Sławomir Kowalczyk

    2013-12-01

    Full Text Available The results of studies of the occurrence of arbuscular mycorrhizal fungi (AMF and arbuscular mycorrhizae of the phylum Glomeromycota associated with roots of 31 cultivated, uncultivated and protected plant species growing at 103 sites of the Lubuskie province NW Poland are presented and discussed. The AMF most frequently found were members of the genus Glomus. Other relatively frequently revealed fungi were Scutellospora spp. Spore populations of AMF generally were more abundant and diverse in cultivated soils. Most protected plant species harboured AMF.

  7. Interactions between arbuscular mycorrhizal fungi and organic material substrates.

    Science.gov (United States)

    Hodge, Angela

    2014-01-01

    Arbuscular mycorrhizal (AM) associations are widespread and form between ca. two-thirds of all land plants and fungi in the phylum Glomeromycota. The association is a mutualistic symbiosis with the fungi enhancing nutrient capture for the plant while obtaining carbon in return. Although arbuscular mycorrhizal fungi (AMF) lack any substantial saprophytic capability they do preferentially associate with various organic substrates and respond by hyphal proliferation, indicating the fungus derives a benefit from the organic substrate. AMF may also enhance decomposition of the organic material. The benefit to the host plant of this hyphal proliferation is not always apparent, particularly regarding nitrogen (N) transfer, and there may be circumstances under which both symbionts compete for the N released given both have a large demand for N. The results of various studies examining AMF responses to organic substrates and the interactions with other members of the soil community will be discussed.

  8. Effect of Arbuscular Mycorrhizal Fungi on Growth and Antioxidant Activity in Gmelina arborea Roxb. under Salt Stress Condition

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    Mayura Prakash DUDHANE

    2011-11-01

    Full Text Available Gmelina arborea Roxb. is medicinally and economically important tree species were selected for study. An experiment was conducted to determine the influence of arbuscular mycorrhizal (AM fungus Glomus fasciculatum on salt stress tolerance of tree species Gmelina arborea. Mycorrhizal and nonmycorrhizal seedlings were treated with 100 mM and 200 mM concentration of NaCl. G. fasciculatum treated plant showed increase in fresh and dry weight, greater percentage of mycorrhizal colonization, higher accumulation of proline and chlorophyll content with increasing levels of salinity. G. fasciculatum colonization significantly increased tolerance of salinity, acid phosphatases, and Proline content and also antioxidant enzymes like peroxidase, catalase and superoxide dismutase at all levels of salinity treatments of Gmelina plants in comparison with non-mycorrhizal salinity treated plants. These results demonstrate that AM fungus (G. fasciculatum is very effective in strengthening the tolerance of Gmelina arborea grown in arid and semi arid areas.

  9. When do arbuscular mycorrhizal fungi protect plant roots from pathogens?

    OpenAIRE

    Sikes, Benjamin A

    2010-01-01

    Arbuscular mycorrhizal (AM) fungi are mainly thought to facilitate phosphorus uptake in plants, but they can also perform several other functions that are equally beneficial. Our recent study sheds light on the factors determining one such function, enhanced plant protection from root pathogens. Root infection by the fungal pathogen Fusarium oxysporum was determined by both plant susceptibility and the ability of an AM fungal partner to suppress the pathogen. The non-susceptible plant species...

  10. Arbuscular Mycorrhizal Symbiosis Alleviates Diesel Toxicity on Melilotus albus

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Ortega, H. A.; Alarcon, A.; Ferrera-Cerrato, R.; Zavaleta-Mancera, H. A.

    2009-07-01

    Petroleum hydrocarbons (PH) affect plant growth and development by limiting water absorption and nutrient availability. Arbuscular mycorrhizal fungi (AMF) have been demonstrated to increase plant tolerance of grass species to PH, but the performance of AMF on legume species during phytorremediation of PH-contaminated soils has been scarcely understood. Thus, this research evaluated the effects of AMF on tolerance and growth of Melilotus albus in a diesel-contaminated soil. (Author)

  11. Investigating the Endobacteria Which Thrive in Arbuscular Mycorrhizal Fungi.

    Science.gov (United States)

    Desirò, Alessandro; Salvioli, Alessandra; Bonfante, Paola

    2016-01-01

    The study of the so-called unculturable bacteria is still considered a challenging task. However, given recent improvements in the sensitivity of culture-free approaches, the identification and characterization of such microbes in complex biological samples is now possible. In this chapter we report how endobacteria thriving inside arbuscular mycorrhizal fungi (AMF), which are themselves obligate biotrophs of plants, can be studied using a combination of in vitro culture, molecular biology, and microscopy techniques. PMID:26791495

  12. Effect of arbuscular mycorrhizal fungi on young vines in copper-contaminated soil

    Directory of Open Access Journals (Sweden)

    Vítor Gabriel Ambrosini

    2015-12-01

    Full Text Available Abstract High copper (Cu levels in uprooted old vineyard soils may cause toxicity in transplanted young vines, although such toxicity may be reduced by inoculating plants with arbuscular mycorrhizal fungi (AMF. The objective of this study was to evaluate the effects of AMF on the plant growth, chlorophyll contents, mycorrhizal colonization, and Cu and phosphorus (P absorption in young vines cultivated in a vineyard soil contaminated by Cu. Commercial vineyard soil with high Cu levels was placed in plastic tubes and transplanted with young vines, which were inoculated with six AMF species (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus, R. irregularis and a control treatment on randomized blocks with 12 replicates. After 130 days, the mycorrhizal colonization, root and shoot dry matter (DM, height increment, P and Cu absorption, and chlorophyll contents were evaluated. The height increment, shoot DM and chlorophyll contents were not promoted by AMF, although the root DM was increased by R. clarus and R. irregularis, which had the greatest mycorrhizal colonization and P uptake. AMF increased Cu absorption but decreased its transport to shoots. Thus, AMF species, particularly R. clarus and R. irregularis, contribute to the establishment of young vines exposed to high Cu levels.

  13. Effect of arbuscular mycorrhizal fungi on young vines in copper-contaminated soil.

    Science.gov (United States)

    Ambrosini, Vítor Gabriel; Voges, Joana Gerent; Canton, Ludiana; Couto, Rafael da Rosa; Ferreira, Paulo Ademar Avelar; Comin, Jucinei José; de Melo, George Wellington Bastos; Brunetto, Gustavo; Soares, Cláudio Roberto Fonsêca Sousa

    2015-01-01

    High copper (Cu) levels in uprooted old vineyard soils may cause toxicity in transplanted young vines, although such toxicity may be reduced by inoculating plants with arbuscular mycorrhizal fungi (AMF). The objective of this study was to evaluate the effects of AMF on the plant growth, chlorophyll contents, mycorrhizal colonization, and Cu and phosphorus (P) absorption in young vines cultivated in a vineyard soil contaminated by Cu. Commercial vineyard soil with high Cu levels was placed in plastic tubes and transplanted with young vines, which were inoculated with six AMF species (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus, R. irregularis) and a control treatment on randomized blocks with 12 replicates. After 130 days, the mycorrhizal colonization, root and shoot dry matter (DM), height increment, P and Cu absorption, and chlorophyll contents were evaluated. The height increment, shoot DM and chlorophyll contents were not promoted by AMF, although the root DM was increased by R. clarus and R. irregularis, which had the greatest mycorrhizal colonization and P uptake. AMF increased Cu absorption but decreased its transport to shoots. Thus, AMF species, particularly R. clarus and R. irregularis, contribute to the establishment of young vines exposed to high Cu levels. PMID:26691462

  14. Influence of salinity on the development of the banana colonised by arbuscular mycorrhizal fungi

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    Aldênia Mendes Mascena de Almeida

    2016-09-01

    Full Text Available ABSTRACT This study evaluated the effect of salt stress on the growth of banana seedling colonized with mycorrhizal fungi (AMF on a substrate from a Quartzipsamment. The experiment was conducted in a greenhouse, using a completely randomized design in split plots; the plots had 5 levels of salinity in irrigation water (0.5, 1.5, 2.5, 3.5 and 4 5 dS m-1 and the subplots of four collection periods (40, 60, 80 and 100 days after transplanting, with 4 repetitions, totaling 80 experimental units. The seedlings of banana cv. "Prata" was produced by micropropagation and inoculated with arbuscular mycorrhizal and acclimatization for 40 days. Evaluations were made of leaf gas exchange, shoot dry mass, nutrient content, mycorrhizal root colonization and spore density. Increased levels of salinity caused reduction in dry matter production and photosynthetic rate, which may be associated with osmotic effects of salts in the soil, the increase in sodium and reduced the levels of N in leaves. Salinity reduced root mycorrhizal colonization, but did not influence the density of AMF spores under the conditions of this study.

  15. Roles of Arbuscular Mycorrhizas in Plant Phosphorus Nutrition: Interactions between Pathways of Phosphorus Uptake in Arbuscular Mycorrhizal Roots Have Important Implications for Understanding and Manipulating Plant Phosphorus Acquisition

    DEFF Research Database (Denmark)

    Smith, S.E.; Jakobsen, Iver; Grønlund, Mette;

    2011-01-01

    In this Update, we review new findings about the roles of the arbuscular mycorrhizas (mycorrhiza = fungus plus root) in plant growth and phosphorus (P) nutrition. We focus particularly on the function of arbuscular mycorrhizal (AM) symbioses with different outcomes for plant growth (from positive...... to negative) and especially on the interplay between direct P uptake via root epidermis (including root hairs when present) and uptake via the AM fungal pathway. The results are highly relevant to many aspects of AM symbiosis, ranging from signaling involved in the development of colonization...

  16. Mycelium of arbuscular mycorrhizal fungi (AMF) from different genera: form function and detection

    NARCIS (Netherlands)

    Dodd, J.C.; Boddington, C.L.; Rodriguez, A.; Gonzalez-Chavez, C.; Marsur, I.

    2000-01-01

    It is often assumed that all species of arbuscular mycorrhizal fungi (AMF) have the same function because of the ubiquity of the arbuscular mycorrhizal symbiosis and the fact that all AMF occupy the same plant/soil niche. Despite apparent differences in the timing of evolutionary divergence and the

  17. Breakdown and delayed cospeciation in the arbuscular mycorrhizal mutualism.

    Science.gov (United States)

    Merckx, Vincent; Bidartondo, Martin I

    2008-05-01

    The ancient arbuscular mycorrhizal association between the vast majority of plants and the fungal phylum Glomeromycota is a dominant nutritional mutualism worldwide. In the mycorrhizal mutualism, plants exchange photosynthesized carbohydrates for mineral nutrients acquired by fungi from the soil. This widespread cooperative arrangement is broken by 'cheater' plant species that lack the ability to photosynthesize and thus become dependent upon three-partite linkages (cheater-fungus-photosynthetic plant). Using the first fine-level coevolutionary analysis of mycorrhizas, we show that extreme fidelity towards fungi has led cheater plants to lengthy evolutionary codiversification. Remarkably, the plants' evolutionary history closely mirrors that of their considerably older mycorrhizal fungi. This demonstrates that one of the most diffuse mutualistic networks is vulnerable to the emergence, persistence and speciation of highly specific cheaters.

  18. Arbuscular mycorrhizal fungal responses to abiotic stresses: A review.

    Science.gov (United States)

    Lenoir, Ingrid; Fontaine, Joël; Lounès-Hadj Sahraoui, Anissa

    2016-03-01

    The majority of plants live in close collaboration with a diversity of soil organisms among which arbuscular mycorrhizal fungi (AMF) play an essential role. Mycorrhizal symbioses contribute to plant growth and plant protection against various environmental stresses. Whereas the resistance mechanisms induced in mycorrhizal plants after exposure to abiotic stresses, such as drought, salinity and pollution, are well documented, the knowledge about the stress tolerance mechanisms implemented by the AMF themselves is limited. This review provides an overview of the impacts of various abiotic stresses (pollution, salinity, drought, extreme temperatures, CO2, calcareous, acidity) on biodiversity, abundance and development of AMF and examines the morphological, biochemical and molecular mechanisms implemented by AMF to survive in the presence of these stresses. PMID:26803396

  19. Arbuscular mycorrhizal fungi decrease radiocesium accumulation in Medicago truncatula

    Energy Technology Data Exchange (ETDEWEB)

    Gyuricza, Veronika; Declerck, Stephane [Universite catholique de Louvain, Earth and Life Institute (ELI), Laboratoire de Mycologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium); Dupre de Boulois, Herve, E-mail: herve.dupre@uclouvain.b [Universite catholique de Louvain, Earth and Life Institute (ELI), Laboratoire de Mycologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium)

    2010-08-15

    The role of arbuscular mycorrhizal fungi (AMF) in plant radiocesium uptake and accumulation remains ambiguous. This is probably due to the presence of other soil microorganisms, the variability of soil characteristics and plant nutritional status or the availability of its chemical analogue, potassium (K). Here, we used an in vitro culture system to study the impact of increased concentration of K on radiocesium accumulation in non K-starved mycorrhizal and non-mycorrhizal Medicago truncatula plants. In the presence of AMF radiocesium uptake decreased regardless of the concentration of K, and its translocation from root to shoot was also significantly lower. Potassium also reduced the accumulation of radiocesium in plants but to a lesser extent than mycorrhization, and without any effect on translocation. These results suggest that AMF in combination with K can play a key role in reducing radiocesium uptake and its subsequent translocation to plant shoots, thereby representing good potential for improved phytomanagement of contaminated areas.

  20. Mycorrhizal colonization, spore density and diversity of arbuscular mycorrhizal fungi in Cerrado soil under no-till and conventional tillage systemsColonização micorrízica, densidade de esporos e diversidade de fungos micorrízicos arbusculares em solo de Cerrado sob plantio direto e convencional

    Directory of Open Access Journals (Sweden)

    José Luiz Rodrigues Torres

    2012-04-01

    Full Text Available The quest for sustainability in agricultural production through conservation management practices such as no-tillage, has favored the biochemical processes of soil, such as soil arbuscular mycorrhizal fungi (AMFs, which promote a significant increase in specific surface absorption of the root system of plants. The objective of this study was to evaluate the root colonization, spore density and diversity of AMFs in rhizosphere of corn and soybean grown under no-tillage with different cover crops and compared an area conventional tillage and fallow, in Uberaba, state of Minas Gerais. The corn and soybeans were rotated with millet, crotalaria and brachiaria. The experimental design was randomized blocks, with split plots. The experiment was established in 2000, and in 2007 assessed the colonization (COL and spore density (ESP (0.0-0.05m and 0.05-0.10m. In the layer of 0.0-0.10m evaluated the diversity of AMFs. It was found that there was a strong effect of culture on COL and ESP. However, the effect of the covers and management was seen only in 0.0-0.05m. The roots of corn has a higher percentages of COL and ESP compared with soybeans, for the coverage Brachiaria and millet. The mycorrhizal colonization of soybean and maize in Cerrado area was up 80% for soybeans and up 95% for corn. Conventional tillage soil the lowest number of AMFs species in relation to the coverage of millet and Brachiaria in no-till corn and soybeans. The principal components analysis with some chemical, physical and biological factors of soil shows the separation of the areas assessed, and the biological component (COL and ESP in the efficient separation of the areas under cultivation, for the conditions of this study.A busca da sustentabilidade na produção agrícola através de manejos conservacionistas, como o sistema plantio direto, tem favorecido os processos bioquímicos do solo como dos fungos micorrízicos arbusculares (FMAs, os quais promovem um aumento expressivo

  1. Microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants in lead contaminated soil

    Directory of Open Access Journals (Sweden)

    Graziella S Gattai

    2011-09-01

    Full Text Available The goals of this study were to evaluate the microbial activity, arbuscular mycorrhizal fungi and inoculation of woody plants (Caesalpinia ferrea, Mimosa tenuiflora and Erythrina velutina in lead contaminated soil from the semi-arid region of northeastern of Brazil (Belo Jardim, Pernambuco. Dilutions were prepared by adding lead contaminated soil (270 mg Kg-1 to uncontaminated soil (37 mg Pb Kg soil-1 in the proportions of 7.5%, 15%, and 30% (v:v. The increase of lead contamination in the soil negatively influenced the amount of carbon in the microbial biomass of the samples from both the dry and rainy seasons and the metabolic quotient only differed between the collection seasons in the 30% contaminated soil. The average value of the acid phosphatase activity in the dry season was 2.3 times higher than observed during the rainy season. There was no significant difference in the number of glomerospores observed between soils and periods studied. The most probable number of infective propagules was reduced for both seasons due to the excess lead in soil. The mycorrhizal colonization rate was reduced for the three plant species assayed. The inoculation with arbuscular mycorrhizal fungi benefited the growth of Erythrina velutina in lead contaminated soil.

  2. Effect of Arbuscular Mycorrhizal Inoculation on Plant Growth and Phthalic Ester Degradation in Two Contaminated Soils

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui-Rui; YIN Rui; LIN Xian-Gui; CAO Zhi-Hong

    2005-01-01

    A 60-day pot experiment was carried out using di-(2-ethylhexyl) phthalate (DEHP) as a typical organic pollutant phthalic ester and cowpea (Vigna sinensis) as the host plant to determine the effect of arbuscular mycorrhizal inoculation on plant growth and degradation of DEHP in two contaminated soils, a yellow-brown soil and a red soil. The air-dried soils were uniformly sprayed with different concentrations of DEHP, inoculated or left uninoculated with an arbuscular mycorrhizal (AM) fungus, and planted with cowpea seeds. After 60 days the positive impact of AM inoculation on the growth of cowpea was more pronounced in the red soil than in the yellow-brown soil, with significantly higher (P < 0.01)mycorrhizal colonization rate, shoot dry weight and total P content in shoot tissues for the red soil. Both in the yellowbrown and red soils, AM inoculation significantly (P < 0.01) reduced shoot DEHP content, implying that AM inoculation could inhibit the uptake and translocation of DEHP from roots to the aboveground parts. However, with AM inoculation no positive contribution to the degradation of DEHP was found.

  3. Arbuscular mycorrhizal colonization of Alnus acuminata Kunth in northwestern Argentina in relation to season and soil parameters Colonización micorrícico arbuscular de Alnus acuminata Kunth en el noroeste argentino en relación a la estacionalidad y a los parámetros edáficos

    Directory of Open Access Journals (Sweden)

    Alejandra Gabriela Becerra

    2007-07-01

    Full Text Available The objective of this study was to determine patterns of arbuscular mycorrhizal (AM colonization of Alnus acuminata Kunth at two natural forests in relation to soil parameters at two different seasons (autumn and spring. The soil parameters studied were field capacity, pH, electrical conductivity, available P, total N and organic matter. The percentage of AM colonization was estimated and correlated to soil properties and to two different seasons. The results indicate that the percentage of AM colonization varied among soil types and was higher in spring than autumn. A significant positive correlation was found between AM colonization and electrical conductivity, organic matter and total Nitrogen. Results of this study provide evidence that AM colonization of A. acuminata can be affected by some soil parameters and seasonality.El objetivo de este estudio fue determinar el patrón de colonización micorrícico arbuscular (MA de Alnus acuminata Kunth en dos bosques del Noroeste Argentino, en relación a los parámetros edáficos y en dos estaciones del año (otoño y primavera. Los parámetros edáficos estudiados fueron: capacidad de campo, pH, conductividad eléctrica, fósforo disponible, N total y materia orgánica. Se cuantificó el porcentaje de colonización MA y se lo correlacionó con las variables estudiadas (parámetros edáficos y estaciones. Los resultados indican que el porcentaje de colonización MA varió entre los dos tipos de suelo y las estaciones, siendo mayor en primavera. Se observó correlación positiva significativa entre el porcentaje de colonización MA y la conductividad eléctrica, materia orgánica y N total. Los resultados de este estudio indican que la colonización MA de A. acuminata puede ser afectada por algunos parámetros edáficos y la estacionalidad.

  4. Effects of arbuscular mycorrhizal fungi inoculation on arsenic accumulation by tobacco (Nicotiana tabacum L.).

    Science.gov (United States)

    Hua, Jianfeng; Lin, Xiangui; Yin, Rui; Jiang, Qian; Shao, Yufang

    2009-01-01

    A pot experiment was conducted to study the effects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminated soils) on arsenic (As) uptake of tobacco (Nicotiana tabacum L.) in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate (fungi isolated from polluted soils were no more effective than those from unpolluted soils when grown in symbiosis with tobacco. No significant differences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not affected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and Al were found in mycorrhizal treatments than in controls. The protective effect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety. PMID:19999968

  5. [Diversity of arbuscular mycorrhizal fungi in special habitats: a review].

    Science.gov (United States)

    Li, Su-Mei; Wang, Yin-Qiao; Liu, Run-Jin

    2013-11-01

    Arbuscular mycorrhizal fungi (AMF) are one of the important components in ecosystems, which not only have the diversity in genetics, species composition, and function, but also have the diversity in distribution and habitat. AMF infect plant root, form mycorrhiza, and nourish as obligate biotroph symbiont, with strong ecological adaptability. They not only distribute in forest, prairie, and farm land, but also distribute in the special habitats with less plant species diversity, such as commercial greenhouse soil, saline-alkali soil, mining pollution land, petroleum-contaminated land, pesticide-polluted soil, desert, dry land, wetland, marsh, plateau, volcanic, cooler, and arctic tundra, composing a unique community structure and playing an important irreplaceable role in the physiological and ecological functions. This paper summarized the species diversity and mycorrhizal morphological features of AMF in special habitats, aimed to provide essential information for the further studies on the AMF in these special habitats and extreme environments.

  6. Arbuscular-mycorrhizal networks inhibit Eucalyptus tetrodonta seedlings in rain forest soil microcosms.

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    David P Janos

    Full Text Available Eucalyptus tetrodonta, a co-dominant tree species of tropical, northern Australian savannas, does not invade adjacent monsoon rain forest unless the forest is burnt intensely. Such facilitation by fire of seedling establishment is known as the "ashbed effect." Because the ashbed effect might involve disruption of common mycorrhizal networks, we hypothesized that in the absence of fire, intact rain forest arbuscular mycorrhizal (AM networks inhibit E. tetrodonta seedlings. Although arbuscular mycorrhizas predominate in the rain forest, common tree species of the northern Australian savannas (including adult E. tetrodonta host ectomycorrhizas. To test our hypothesis, we grew E. tetrodonta and Ceiba pentandra (an AM-responsive species used to confirm treatments separately in microcosms of ambient or methyl-bromide fumigated rain forest soil with or without severing potential mycorrhizal fungus connections to an AM nurse plant, Litsea glutinosa. As expected, C. pentandra formed mycorrhizas in all treatments but had the most root colonization and grew fastest in ambient soil. E. tetrodonta seedlings also formed AM in all treatments, but severing hyphae in fumigated soil produced the least colonization and the best growth. Three of ten E. tetrodonta seedlings in ambient soil with intact network hyphae died. Because foliar chlorosis was symptomatic of iron deficiency, after 130 days we began to fertilize half the E. tetrodonta seedlings in ambient soil with an iron solution. Iron fertilization completely remedied chlorosis and stimulated leaf growth. Our microcosm results suggest that in intact rain forest, common AM networks mediate belowground competition and AM fungi may exacerbate iron deficiency, thereby enhancing resistance to E. tetrodonta invasion. Common AM networks-previously unrecognized as contributors to the ashbed effect-probably help to maintain the rain forest-savanna boundary.

  7. Diversity of Arbuscular Mycorrhizal Fungi and its Influence on Soil Dynamics

    Science.gov (United States)

    Turner, K. M.; Treseder, K. K.

    2002-12-01

    The diversity of arbuscular mycorrhizal fungi (AMF) has been correlated with increased plant biodiversity, productivity, and fecundity. However, the influence of AMF diversity on below-ground ecosystem characteristics has yet to be determined. A greenhouse experiment was conducted to examine these interactions. Pot cultures containing equal numbers of four common grass species were either inoculated with one of four AMF species, a mixture of all four species, or were not inoculated, for a total of six different community compositions. After two months of growth, the pot cultures were harvested. Results indicated both individual species effects and diversity effects on factors controlling ecosystem-level processes. Bacterial abundance, bacterial diversity, glomalin concentration, hyphal colonization of roots, and above ground plant biomass exhibited significant differences among treatments. However, N mineralization rates, nitrification rates, and levels of organic matter did not respond significantly to treatments. Bacterial diversity, bacterial abundance, and above ground biomass displayed a similar pattern across treatments, and this may indicate potential interactions among AMF, bacteria, and plants. Specifically, the non-mycorrhizal treatment produced the highest values for all three of these characters while the Glomus intraradices monoculture produced the lowest values. Species also varied in production of glomalin, a compound associated with carbon sequestration, with Gigaspora gigantea producing the highest concentration of 1.67mg/g soil and Glomus etunicatumproducing the lowest concentration of 0.63 mg/g soil. Arbuscular mycorrhizal diversity significantly effected the total amount of fungal root colonization (high diversity: 70.9 percent; monocultures: 46.1-63.3 percent) and fungal fecundity and had a marginally significant influence on the abundance of external hyphae. This increased fungal abundance suggested niche complimentarity and positive species

  8. Low concentration of copper inhibits colonization of soil by the arbuscular mycorrhizal fungus Glomus intraradices and changes the microbial community structure

    DEFF Research Database (Denmark)

    Hagerberg, David; Manique, Nina; Brandt, Kristian Koefoed;

    2011-01-01

    Common agricultural practices result in accumulation of copper in agricultural soils worldwide. The effect of bioavailable copper ([Cu]bio) on colonization of soil by the AM fungus Glomus intraradices and other soil microorganisms was investigated in microcosms containing copper-amended soil. To ...

  9. Arbuscular mycorrhizal fungi alter the response of growth and nutrient uptake of snap bean (Phaseolus vulgaris L.) to O3

    Institute of Scientific and Technical Information of China (English)

    Shuguang Wang; Zhaozhong Feng; Xiaoke Wang; Wenliang Gong

    2011-01-01

    The effects of arbuscular mycorrhizal fungi (AMF) Glomus mosseae on the responses to elevated O3 in growth and nutrition of snap bean (Phaseolus vulgaris L. cv Guangzhouyuan) were investigated. Exposure was conducted in growth chambers by using three O3 concentrations (20 (CF), 80 (CFO1) and 120 nL/L (CFO2); 8 hr/day for 75 days). Results showed that elevated O3 slightly impacted overall mycorrhizal colonization, but significantly decreased the proportional frequency of hypha and increased the proportional frequency of spores and vesicles, suggesting that O3 had significant effects on mycorrhizal structure. Elevated O3 significantly decreased yield, dry mass and nutrient contents (N, P, K, Ca and Mg) in both non-mycorrhizal and mycorrhizal plants. However, significant interactive effects were found in most variables due to that the reduction by O3 in the mycorrhizal plants was less than that in the non-mycorrhizal plants. Additionally, AMF increased the concentrations of N, P, Ca, and Mg in shoot and root. It can be concluded that AMF alleviated detrimental effects of increasing O3 on host plant through improving plant nutrition and growth.

  10. Arbuscular mycorrhizal fungi counteract the Janzen-Connell effect of soil pathogens

    NARCIS (Netherlands)

    Liang, Minxia; Liu, Xubing; Etienne, Rampal S; Huang, Fengmin; Wang, Yongfan; Yu, Shixiao

    2015-01-01

    Soilborne pathogens can contribute to diversity maintenance in tree communities through the Janzen-Connell effect, whereby the pathogenic reduction of seedling performance attenuates with distance from conspecifics. By contrast, arbuscular mycorrhizal fungi (AMF) have been reported to promote seedli

  11. Community structure of arbuscular mycorrhizal fungi associated to Veronica rechingeri at the Anguran zinc and lead mining region

    Energy Technology Data Exchange (ETDEWEB)

    Zarei, M. [Department of Soil Science Engineering, Soil and Water Engineering Faculty, University College of Agriculture and Natural Resources, University of Tehran, Karaj (Iran, Islamic Republic of)], E-mail: mehdizarei20@yahoo.ca; Koenig, S. [UFZ Helmholtz Center for Environmental Research Leipzig-Halle Ltd, Department of Soil Ecology, Theodor-Lieser-Strasse 4, D-06120 Halle (Germany)], E-mail: stephan.koenig@ufz.de; Hempel, S. [UFZ Helmholtz Center for Environmental Research Leipzig-Halle Ltd, Department of Soil Ecology, Theodor-Lieser-Strasse 4, D-06120 Halle (Germany)], E-mail: hempel.stefan@gmail.com; Nekouei, M. Khayam [Agricultural Biotechnology Research Institute of Iran (ABRII), P.O. Box 31535-1897, Karaj (Iran, Islamic Republic of)], E-mail: Khayam@abrii.ac.ir; Savaghebi, Gh. [Department of Soil Science Engineering, Soil and Water Engineering Faculty, University College of Agriculture and Natural Resources, University of Tehran, Karaj (Iran, Islamic Republic of)], E-mail: Savagheb@ut.ac.ir; Buscot, F. [UFZ Helmholtz Center for Environmental Research Leipzig-Halle Ltd, Department of Soil Ecology, Theodor-Lieser-Strasse 4, D-06120 Halle (Germany)], E-mail: francois.buscot@ufz.de

    2008-12-15

    Root colonization and diversity of arbuscular mycorrhizal fungi (AMF) were analyzed in Veronica rechingeri growing in heavy metal (HM) and non-polluted soils of the Anguran Zn and Pb mining region (Iran). Three species could be separated morphologically, while phylogenetic analyses after PCR amplification of the ITS region followed by RFLP and sequencing revealed seven different AMF sequence types all within the genus Glomus. Rarefaction analysis confirmed exhaustive molecular characterization of the AMF diversity present within root samples. Increasing heavy metal contamination between the sites studied was accompanied by a decrease in AMF spore numbers, mycorrhizal colonization parameters and the number of AMF sequence types colonizing the roots. Some AMF sequence types were only found at sites with the highest and lowest soil HM contents, respectively. - The increase in soil heavy metal content between sites was accompanied by a decrease in mycorrhization parameters, spore numbers and AMF molecular diversity.

  12. Community analysis of arbuscular mycorrhizal fungi in roots of Poncirus trifoliata and Citrus reticulata based on SSU rDNA.

    Science.gov (United States)

    Wang, Peng; Wang, Yin

    2014-01-01

    Morphological observation of arbuscular mycorrhizal fungi (AMF) species in rhizospheric soil could not accurately reflect the actual AMF colonizing status in roots, while molecular identification of indigenous AMF colonizing citrus rootstocks at present was rare in China. In our study, community of AMF colonizing trifoliate orange (Poncirus trifoliata L. Raf.) and red tangerine (Citrus reticulata Blanco) were analyzed based on small subunit of ribosomal DNA genes. Morphological observation showed that arbuscular mycorrhizal (AM) colonization, spore density, and hyphal length did not differ significantly between two rootstocks. Phylogenetic analysis showed that 173 screened AMF sequences clustered in at least 10 discrete groups (GLO1~GLO10), all belonging to the genus of Glomus Sensu Lato. Among them, GLO1 clade (clustering with uncultured Glomus) accounting for 54.43% clones was the most common in trifoliate orange roots, while GLO6 clade (clustering with Glomus intraradices) accounting for 35.00% clones was the most common in red tangerine roots. Although, Shannon-Wiener indices exhibited no notable differences between both rootstocks, relative proportions of observed clades analysis revealed that composition of AMF communities colonizing two rootstocks varied severely. The results indicated that native AMF species in citrus rhizosphere had diverse colonization potential between two different rootstocks in the present orchards. PMID:25162057

  13. Plant growth depressions in arbuscular mycorrhizal symbioses: not just caused by carbon drain?

    Science.gov (United States)

    Li, Huiying; Smith, F Andrew; Dickson, Sandy; Holloway, Robert E; Smith, Sally E

    2008-01-01

    * This study investigated effects of plant density and arbuscular mycorrhizal (AM) colonization on growth and phosphorus (P) nutrition of a cultivar of wheat (Triticum aestivum) that often shows early AM-induced growth depressions. * Two experiments were conducted. Expt 1 had three plant densities and one soil P concentration. Expt 2 had two plant densities and two P concentrations. Plants were grown in calcareous P-fixing soil, inoculated with Glomus intraradices or Gigaspora margarita, or noninoculated (nonmycorrhizal (NM)). Glomus intraradices colonized well and caused a growth depression only in Expt 1. Gigaspora margarita caused large growth depressions in both experiments even though it colonized poorly. * The results showed that growth depressions were mitigated by changes in relative competition for soil P by NM and AM plants, and probably by decreasing carbon costs of the fungi. * The different effects of the two fungi appear to be attributable to differences in the balance between P uptake by the fungal pathway and direct uptake via the roots. These differences may be important in other AM symbioses that result in growth depressions. The results show that mycorrhizal growth responses of plants grown singly may not apply at the population or community level.

  14. Do arbuscular mycorrhizal fungi affect arsenic accumulation and speciation in rice with different radial oxygen loss?

    Science.gov (United States)

    Li, H; Man, Y B; Ye, Z H; Wu, C; Wu, S C; Wong, M H

    2013-11-15

    The effects of arbuscular mycorrhizal fungi (AMF) on the temporal variation of arsenic (As) speciation and accumulation in two paddy rice cultivars (TD 71 and Xiushui 11) with different degrees of radial oxygen loss (ROL) at three growth periods (day 7, day 35, day 63 after flooding the soil) were investigated in soil, spiked with and without 30 mg As kg(-1). The results showed that TD 71 with high ROL colonized by Glomus intraradices led to higher root colonization rates than Xiushui 11 at three growth periods, both in soil with or without 30 mg As kg(-1) (p<0.05). Mycorrhizal inoculation led to elevated (p<0.05) root ratios of arsenite (As(III)) conc./arsenate (As(V)) conc. (concentration) in TD 71 with high ROL at three growth periods in As contaminated flooding soils. Furthermore, the ratios of As(III) conc./As(V) conc. in roots of TD71 were significantly more than Xiushui 11 when colonized by AMF at three growth periods in 30 mg As kg(-1) soil (p<0.05). Therefore, rice with high ROL can favor AM fungal infection and enhance root ratio of As(III) conc./As(V) conc. in the presence of AMF.

  15. ARBUSCULAR MYCORRHIZAL IN NATIVE WOODY SPECIES OF TIBAGI RIVER BASIN, PARANÁ

    Directory of Open Access Journals (Sweden)

    Emilia M. Nakano

    2002-01-01

    Full Text Available The incidence of arbuscular mycorrhizal (AM and response to inoculation of 81 native woody species from Tibagi river basin, Paraná State, South Brazil, under greenhouse conditions are reported. The AM colonization incidence of 51 native woody species collected in the area at the beginning of arboreal succession and in the interior of the forest of the Parque Estadual Mata dosGodoy (23° 27' S e 51o 15' W is also analysed. The response to inoculation and AM colonization in greenhouse were in general high between the pioneer and early secondary species, and low between the late secondary and climax species. In nine arboreal species belonging to the late secondary and climax species did not show response to inoculation. The incidence of AM colonization in root samples collected in the field was high to intermediate among the pioneer and early secondary species and was low to very low between the late secondary and climax species. Peltophorum dubium (canafístula, Zeyheria tuberculosa (ipê-felpudo e Aspidosperma polyneuron (peroba-rosa did not have response to inoculation and AM colonization of the roots from both the greenhouse and field. All other species showed AM colonization which changed from very high to very low, indicating that the occurrence of AM colonization is generalized among native woody species. The woody species belonging to the early phases of succession were more susceptible to AM symbiosis than later successional species.

  16. Impact of an invasive nitrogen-fixing tree on arbuscular mycorrhizal fungi and the development of native species.

    Science.gov (United States)

    Guisande-Collazo, Alejandra; González, Luís; Souza-Alonso, Pablo

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate soil biotrophs that establish intimate relationships with 80 % of terrestrial plant families. Arbuscular mycorrhizal fungi obtain carbon from host plants and contribute to the acquisition of mineral nutrients, mainly phosphorus. The presence of invasive plants has been identified as a soil disturbance factor, often conditioning the structure and function of soil microorganisms. Despite the investigation of many aspects related to the invasion ofAcacia dealbata, the effect produced on the structure of AMF communities has never been assessed. We hypothesize thatA. dealbatamodifies the structure of AMF community, influencing the establishment and growth of plants that are dependent on these mutualisms. To validate our hypothesis, we carried out denaturing gradient gel electrophoresis (DGGE) analysis and also grew plants ofPlantago lanceolatain pots using roots of native shrublands or fromA. dealbata, as inoculum of AMF. Cluster analyses from DGGE indicated an alteration in the structure of AMF communities in invaded soils. After 15 weeks, we found that plants grown in pots containing native roots presented higher stem and root growth and also produced higher biomass in comparison with plants grown withA. dealbatainoculum. Furthermore, plants that presented the highest biomass and growth exhibited the maximum mycorrhizal colonization and phosphorus content. Moreover, fluorescence measurements indicated that plants grown withA. dealbatainoculum even presented higher photosynthetic damage. Our results indicate that the presence of the invaderA. dealbatamodify the composition of the arbuscular fungal community, conditioning the establishment of native plants. PMID:26984185

  17. Native arbuscular mycorrhizal fungi in the Yungas forests, Argentina.

    Science.gov (United States)

    Becerra, Alejandra G; Cabello, Marta N; Bartoloni, Norberto J

    2011-01-01

    The arbuscular mycorrhizal fungal (AMF) communities from the Yungas forests of Argentina were studied. The AMF species present in the rhizosphere of some dominant native plants (one tree: Alnus acuminata; three herbaceous species: Duchesnea indica, Oxalis conorrhiza, Trifolium aff. repens; and one shrub: Sambucus peruviana) from two sites (Quebrada del Portugués and Narváez Range) of the Yungas forests were isolated, identified and quantified during the four seasons of the year. Twenty-two AMF morphotaxa were found. Spore density of some AMF species at each site varied among seasons. The genera that most contributed to the biodiversity index were Acaulospora for Quebrada del Portugués and Glomus for Narváez Range. High diversity values were observed in the Yungas forests, particularly in the spring (rainy season). We concluded AMF differed in species composition and seasonal sporulation dynamics in the Yungas forests. PMID:21415289

  18. Alleviation of drought stress of marigold (Tagetes erecta) plants by using arbuscular mycorrhizal fungi

    OpenAIRE

    Asrar, Abdul-Wasea A.; Elhindi, Khalid M.

    2010-01-01

    The effect of an arbuscular mycorrhizal fungus “AMF” (Glomus constrictum Trappe) on growth, pigments, and phosphorous content of marigold (Tagetes erecta) plant grown under different levels of drought stress was investigated. The applied drought stress levels reduced growth vigor (i.e. plant height, shoot dry weight, flower diameter as well as its fresh and dry weights) of mycorrhizal and non-mycorrhizal plant as compared to control plant (non-drought stressed plant). The presence of mycorrhi...

  19. Apocarotenoid biosynthesis in arbuscular mycorrhizal roots: contributions from methylerythritol phosphate pathway isogenes and tools for its manipulation.

    Science.gov (United States)

    Walter, Michael H; Floss, Daniela S; Hans, Joachim; Fester, Thomas; Strack, Dieter

    2007-01-01

    During colonization by arbuscular mycorrhizal (AM) fungi plant roots frequently accumulate two types of apocarotenoids (carotenoid cleavage products). Both compounds, C(14) mycorradicin and C(13) cyclohexenone derivatives, are predicted to originate from a common C(40) carotenoid precursor. Mycorradicin is the chromophore of the "yellow pigment" responsible for the long-known yellow discoloration of colonized roots. The biosynthesis of apocarotenoids has been investigated with a focus on the two first steps of the methylerythritol phosphate (MEP) pathway catalyzed by 1-deoxy-D-xylulose 5-phosphate synthase (DXS) and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR). In Medicago truncatula and other plants the DXS2 isogene appears to be specifically involved in the AM-mediated accumulation of apocarotenoids, whereas in the case of DXR a single gene contributes to both housekeeping and mycorrhizal (apo)carotenoid biosynthesis. Immunolocalization of DXR in mycorrhizal maize roots indicated an arbuscule-associated protein deposition, which occurs late in arbuscule development and accompanies arbuscule degeneration and breakdown. The DXS2 isogene is being developed as a tool to knock-down apocarotenoid biosynthesis in mycorrhizal roots by an RNAi strategy. Preliminary results from this approach provide starting points to suggest a new kind of function for apocarotenoids in mycorrhizal roots.

  20. Differences in the composition of arbuscular mycorrhizal fungal communities promoted by different propagule forms from a Mediterranean shrubland.

    Science.gov (United States)

    Varela-Cervero, Sara; López-García, Álvaro; Barea, José Miguel; Azcón-Aguilar, Concepción

    2016-07-01

    As it is well known, arbuscular mycorrhizal (AM) colonization can be initiated from the following three types of fungal propagules: spores, extraradical mycelium (ERM), and mycorrhizal root fragments harboring intraradical fungal structures. It has been shown that biomass allocation of AM fungi (AMF) among these three propagule types varies between fungal taxa, as also differs the ability of the different AMF propagule fractions to initiate new colonizations. In this study, the composition of the AMF community in the roots of rosemary (Rosmarinus officinalis L., a characteristic Mediterranean shrub), inoculated with the three different propagule types, was analyzed. Accordingly, cuttings from this species were inoculated with either AMF spores, ERM, or colonized roots extracted from a natural soil. The AMF diversity within the rosemary roots was characterized using terminal restriction fragment length polymorphism (T-RFLP) of the small subunit (SSU) rDNA region. The AMF community established in the rosemary plants was significantly different according to the type of propagule used as inoculum. AMF taxa differed in their ability to initiate new colonizations from each propagule type. Results suggest different colonization strategies for the different AMF families involved, Glomeraceae and Claroideoglomeraceae colonizing mainly from colonized roots whereas Pacisporaceae and Diversisporaceae from spores and ERM. This supports that AMF taxa show contrasting life-history strategies in terms of their ability to initiate new colonizations from the different propagule types. Further research to fully understand the colonization and dispersal abilities of AMF is essential for their rational use in ecosystem restoration programs. PMID:26883142

  1. Arbuscular mycorrhizal associations in different forest tree species of Hazarikhil forest of Chittagong, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    P.P.Dhar; M.A.U.Mridha

    2012-01-01

    Biodiversity ofarbuscular mycorrhizal (AM) colonization and AM fungal spores were studied in the roots and rhizosphere soils of Acacia catechu (L.f).Wild.,A.mangium Willd,Anthocephala cadamba Miq.,Artocarpus chaplasha Roxb.,Chickrassia tabularis A.Juss.,Swietenia macrophylla King.,Tectona grandis L.from plantations; Albizia procera (Roxb.) Benth.,A.falcataria L.,Alstonia scholaris (L.) R.Br.,Aphanamixis polystachya (Wall.) Parker.,Hydnocarpus kurzii (King.)Warb.,Heynea trijuga Roxb.,Lagerstroemia speciosa (L.) Pers.,Messua ferrea Linn.,Podocarpus nerifolia Don.,Swintonia floribunda Griff.,Syzygium fruticosum (Roxb.) DC.,S.grandis (Wt.) Wal.from forest and nursery seedlings of A.polystachya,A.chaplasha,Gmelina arborea Roxb.and S.cuminii (L.) Skeels from Hazarikhil forest,Chittagong of Bangladesh.Roots were stained in aniline blue and rhizosphere soils were assessed by wet sieving and decanting methods.The range of AM colonization varied significantly from 10%-73% in the plantations samples.Maximum colonization was observed in A.mangium (73%) and minimum colonization was observed in C tabularis (10%).Vesicular colonization was recorded 15%-67% in five plantation tree species.The highest was in A.cadamba (67%) and the lowest was in T.grandis; A.chaplasha and C tabularis showed no vesicular colonization.Arbuscular colonization was recorded 12%-60% in four plantation tree species.The highest was in A.mangium (60%) and the lowest was in A.cadamba.Roots of Artocarpus chaplasha,C tabularis and T.grandis showed no arbuscular colonization.Among 12 forest tree species,nine tree species showed AM colonization.The highest was in A.falcataria (62%) and the lowest was in S.fruticosum (10%).Significant variation in vesicular colonization was recorded in seven forest tree species.The highest was in H.trijuga (52%) and the lowest was in L.speciosa (18%).Hydnocarpus kurzii,M.ferrea,P.nerifolia S.fruticosum and S.grandis showed no vesicular colonization.Arbuscular colonization was

  2. Arbuscular mycorrhizal fungi (Glomeromycota of soils of the Lubuskie province

    Directory of Open Access Journals (Sweden)

    Sławomir Kowalczyk

    2012-12-01

    Full Text Available In the year 2003, the occurrence of arbuscular mycorrhizal fungi (AMF of the phylum Glomeromycota in cultivated and uncultivated soils of the Lubuskie province was investigated. The occurrence of AMF was examined based on 56 root and rhizosphere soils collected under 7 species of cultivated and uncultivated plants growing in 28 localities. Spores of AMF were isolated from both field-collected samples and trap cultures. They were revealed in 100% of field soils and 93.8% of trap cultures and represented 7 of the 8 recognized genera of the Glomeromycota. The arbuscular fungi occurring distinctly more frequently in the soil and root samples examined were members of the genus Glomus. The species of AMF most frequently occurring in cultivated soils of the Lubuskie province were G. claroideum, G. constrictum, G. deserticola and G. mosseae, whereas G. claroideum, G. constrictum, G. deserticola, G. mosseae, and S. dipurpurescens were more frequently found in uncultivated sites. The analysis of similarity of the species composition of AMF populations in sites of the Lubuskie province and the Western Pomeranian province earlier examined showed that (1 the occurrence in Poland of most taxa of these fungi detected in the study presented here is even and does not change with time, (2 the communities of AMF area are stable, despite the arduousness resulting from the agricultural and chemical practices conducted, and (3 the species diversity of the plants cultivated in a long period of time has no influence on the species composition of populations of AMF.

  3. 454-sequencing reveals stochastic local reassembly and high disturbance tolerance within arbuscular mycorrhizal fungal communities

    DEFF Research Database (Denmark)

    Lekberg, Karin Ylva Margareta; Schnoor, Tim; Kjøller, Rasmus;

    2012-01-01

    1. Disturbance is assumed to be a major driver of plant community composition, but whether similar processes operate on associated soil microbial communities is less known. Based on the assumed trade-off between disturbance tolerance and competiveness, we hypothesize that a severe disturbance...... applied within a semi-natural grassland would shift the arbuscular mycorrhizal (AM) fungal community towards disturbance-tolerant fungi that are rare in undisturbed soils. 2. We used 454-sequencing of the large subunit rDNAregion to characterizeAMfungal communities in Plantago lanceolata roots grown...... in the field for 4 months and exposed either to no disturbance or to severe disturbance where fungi from undisturbed soil were either permitted or prevented from re-colonizing the disturbed area. This allowed for a distinction between AM fungi that survived the disturbance and those that quickly re...

  4. Mechanical soil disturbance as a determinant of arbuscular mycorrhizal fungal communities in semi-natural grassland

    DEFF Research Database (Denmark)

    Schnoor, Tim Krone; Lekberg, Ylva; Rosendahl, Søren;

    2011-01-01

    to Diversisporaceae. Only three phylotypes were closely related to known morphospecies. Soil disturbance significantly reduced phylotype richness and changed the AM fungal community composition. Most phylotypes, even closely related ones, showed little or no overlap in their distribution and occurred in either......While the effect of disturbance on overall abundance and community composition of arbuscular mycorrhizal (AM) fungi has been researched in agricultural fields, less is known about the impact in semi-natural grasslands. We sampled two AM plant species, Festuca brevipila and Plantago lanceolata, from...... the control or disturbed plots. We found no evidence of host preference in this system, except for one phylotype that preferentially seemed to colonize Festuca. Our results show that disturbance imposed a stronger structuring force for AM fungal communities than did host plants in this semi-natural grassland....

  5. Evolutionary conservation of a phosphate transporter in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Karandashov, Vladimir; Nagy, Réka; Wegmüller, Sarah; Amrhein, Nikolaus; Bucher, Marcel

    2004-04-20

    Arbuscular mycorrhizae are ancient symbioses that are thought to have originated >400 million years ago in the roots of plants, pioneering the colonization of terrestrial habitats. In these associations, a key process is the transfer of phosphorus as inorganic phosphate to the host plant across the fungus-plant interface. Mycorrhiza-specific phosphate transporter genes and their regulation are conserved in phylogenetically distant plant species, and they are activated selectively by fungal species from the phylum Glomeromycota. The potato phosphate transporter gene StPT3 is expressed in a temporally defined manner in root cells harboring various mycorrhizal structures, including thick-coiled hyphae. The results highlight the role of different symbiotic structures in phosphorus transfer, and they indicate that cell-cell contact between the symbiotic partners is required to induce phosphate transport.

  6. Arbuscular mycorrhizal infection in two morphological root types of Araucaria araucana (Molina) K. Koch.

    Science.gov (United States)

    Diehl, P; Fontenla, S B

    2010-01-01

    Araucaria araucana (Molina) K. Koch is a conifer distributed in the Andean-Patagonian forests in the south of Argentina and Chile. The main objective of this work was to relate the different root classes appearing in A. araucana to mycorrhizal behavior. Samples were collected in three different sites in the Lanín National Park (NW Patagonia, Argentina). Two different root classes were present in A. araucana: longitudinal fine roots (LFR) and globular short roots (GSR). Both had extensive mycorrhizal arbuscular symbiosis (AM) and presented abundant hyphae and coils in root cells, a characteristic of the anatomical Paris-type. Dark septate fungal endophytes were also observed. Values of total AM colonization were high, with similar partial AM% values for each root class. Seasonal differences were found for total and partial colonization, with higher values in spring compared to autumn. Regarding the percentage of fungal structures between root classes, values were similar for vesicles and arbuscules, but higher coil percentages were observed in GSR compared to LFR. The percentages of vesicles increased in autumn, whereas the arbuscule percentages increased in spring, coinciding with the plant growth peak. Results show that both root classes of A. araucana in Andean-Patagonian forests are associated with AM fungi, which may have ecological relevance in terms of the importance of this symbiosis, in response to soil nutrient-deficiencies, especially high P-retention. PMID:20589337

  7. Effects of the arbuscular mycorrhizal fungus Glomus mosseae on growth and metal uptake by four plant species in copper mine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B.D. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China)]. E-mail: bdchen@rcees.ac.cn; Zhu, Y.-G. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Duan, J. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Xiao, X.Y. [Department of Soil Environmental Science, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Smith, S.E. [Centre for Soil-Plant Interactions, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia)

    2007-05-15

    A greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (AMF) in encouraging revegetation of copper (Cu) mine tailings. Two native plant species, Coreopsis drummondii and Pteris vittata, together with a turf grass, Lolium perenne and a leguminous plant Trifolium repens associated with and without AMF Glomus mosseae were grown in Cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. Results indicated that symbiotic associations were successfully established between G. mosseae and all plants tested, and mycorrhizal colonization markedly increased plant dry matter yield except for L. perenne. The beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by both improved P nutrition and decreased shoot Cu, As and Cd concentrations. The experiment provided evidence for the potential use of local plant species in combination with AMF for ecological restoration of metalliferous mine tailings. - This study demonstrated that AM associations can encourage plant survival in Cu mine tailings.

  8. Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Warynski at different soil depths

    Energy Technology Data Exchange (ETDEWEB)

    Gucwa-Przepiora, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Romkens, P.F.A.M. [University of Silesia, Katowice (Poland)

    2007-12-15

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colonization and arbuscule abundance were studied. Correlations between concentration of bioavailable Cd, Zn, Pb and Cu in soil and mycorrhizal parameters were estimated. An increase in AM colonization with increasing soil depth was observed in soils with spontaneously, growing D. cespitosa. A positive effect of chemophytostabilization amendments (calcium phosphate, lignite) on AM colonization was found in the soil layers to which the amendments were applied. Negative correlation coefficients between mycorrhizal parameters and concentration of bioavailable Cd and Zn in soil were obtained. Our results demonstrated that chemophytostabilization practices enhance AM colonization in D. cespitosa roots, even in soils fertilized with high rates of phosphorus.

  9. Rapid assessment of acid phosphatase activity in the mycorrhizosphere and in arbuscular mycorrhizal fungal hyphae

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A pot experiment has been carried out under controlled conditions to study the possibility of applying the technique of in vivo staining for acid phosphatase activity on the roots of mycorrhizal plants and arbuscular mycorrhizal hyphae. The pots had 5 compartments. The central root compartment was separated from the two adjacent hyphal compartments using nylon nets of 30 m m mesh, and the two hyphal compartments were separated from the two outermost compartments with 0.45 m m membranes. Red clover was grown in the root compartment and was either inoculated with the arbuscular mycorrhizal fungus (AMF) Glomus mosseae or uninoculated. Sodium phytate was applied to all compartments. The results show that AMF can increase acid phosphatase activity of clover roots. The plant roots acquired deep red "mycorrhizal prints". The external hyphae also had obvious "hyphal prints" on the test papers, indicating the ability of mycorrhizal hyphae to release acid phosphatase.

  10. Tree species as hosts for arbuscular mycorrhizal and dark septate endophyte fungi

    Institute of Scientific and Technical Information of China (English)

    E.Uma; K.Sathiyadash; J.Loganathan; T.Muthukumar

    2012-01-01

    A survey of 35 tree species (belonging to 28 genera in 19families) in Aliyar,South India was carried out to ascertain their arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal status.All the tree species examined had AM association.AM and DSE colonization is reported for the first time in 20 and 14 species respectively.Cooccurrence of AM and DSE was observed in 14 (40%) tree species.The extent of DSE colonization was inversely related to the extent of AM fungal colonization.Six tree species had Arum-type,18 had intermediatetype and 1l had typical Paris-type AM morphology.AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil.AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity.AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species.The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.

  11. The Use of Arbuscular Mycorrhizal Fungi to Improve Strawberry Production in Coir Substrate.

    Science.gov (United States)

    Robinson Boyer, Louisa; Feng, Wei; Gulbis, Natallia; Hajdu, Klara; Harrison, Richard J; Jeffries, Peter; Xu, Xiangming

    2016-01-01

    Strawberry is an important fruit crop within the UK. To reduce the impact of soil-borne diseases and extend the production season, more than half of the UK strawberry production is now in substrate (predominantly coir) under protection. Substrates such as coir are usually depleted of microbes including arbuscular mycorrhizal fungi (AMF) and consequently the introduction of beneficial microbes is likely to benefit commercial cropping systems. Inoculating strawberry plants in substrate other than coir has been shown to increase plants tolerance to soil-borne pathogens and water stress. We carried out studies to investigate whether AMF could improve strawberry production in coir under low nitrogen input and regulated deficit irrigation. Application of AMF led to an appreciable increase in the size and number of class I fruit, especially under either deficient irrigation or low nitrogen input condition. However, root length colonization by AMF was reduced in strawberry grown in coir compared to soil and Terragreen. Furthermore, the appearance of AMF colonizing strawberry and maize roots grown in coir showed some physical differences from the structure in colonized roots in soil and Terragreen: the colonization structure appeared to be more compact and smaller in coir. PMID:27594859

  12. The Use of Arbuscular Mycorrhizal Fungi to Improve Strawberry Production in Coir Substrate

    Science.gov (United States)

    Robinson Boyer, Louisa; Feng, Wei; Gulbis, Natallia; Hajdu, Klara; Harrison, Richard J.; Jeffries, Peter; Xu, Xiangming

    2016-01-01

    Strawberry is an important fruit crop within the UK. To reduce the impact of soil-borne diseases and extend the production season, more than half of the UK strawberry production is now in substrate (predominantly coir) under protection. Substrates such as coir are usually depleted of microbes including arbuscular mycorrhizal fungi (AMF) and consequently the introduction of beneficial microbes is likely to benefit commercial cropping systems. Inoculating strawberry plants in substrate other than coir has been shown to increase plants tolerance to soil-borne pathogens and water stress. We carried out studies to investigate whether AMF could improve strawberry production in coir under low nitrogen input and regulated deficit irrigation. Application of AMF led to an appreciable increase in the size and number of class I fruit, especially under either deficient irrigation or low nitrogen input condition. However, root length colonization by AMF was reduced in strawberry grown in coir compared to soil and Terragreen. Furthermore, the appearance of AMF colonizing strawberry and maize roots grown in coir showed some physical differences from the structure in colonized roots in soil and Terragreen: the colonization structure appeared to be more compact and smaller in coir. PMID:27594859

  13. The effect of different land uses on arbuscular mycorrhizal fungi in the northwestern Black Sea Region.

    Science.gov (United States)

    Palta, Şahin; Lermi, Ayşe Genç; Beki, Rıdvan

    2016-06-01

    The object of the present research was to establish correlations between the status of root colonization of arbuscular mycorrhizal fungi (AMF) and different types of land use. In order to achieve this aim, rhizosphere soil samples from grassland crops were taken during June and July of 2013 in order to use for determining several soil characteristics. The 27 different taxa and 60 soil samples were collected from the rhizosphere level in the study areas. The existence of AMF was confirmed in 100 % of these plants with different rations of colonization (approximately 12-89 %). Bromus racemosus L. (pasture) was the most dense taxon with the percentage of AMF colonization of 88.9 %, and Trifolium pratense L. (forest) was the least dense taxon with the percentage of AMF colonization of 12.2 % (average 52.0 %). As a result of the statistical analysis, a positive relationship was found between the botanical composition of legumes and AMF colonization (r = 0.35; p = 0.006). However, a negative relationship was determined between botanical composition of other plant families and AMF colonization (r = -0.39; p = 0.002). In addition, a positive relationship was defined between soil pH (H2O) and the root colonization of AMF (r = 0.35; p = 0.005). The pasture had the highest mean value of AMF root colonization. However, the pasture and gap in the forest were in the same group, according to the results of the S-N-K test. PMID:27178052

  14. Arsenic uptake by arbuscular mycorrhizal maize (Zea mays L.) grown in an arsenic-contaminated soil with added phosphorus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As)uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment. Non-mycorrhizal and zero-P addition controls were included. Plant biomass and concentrations and uptake of As, P, and other nutrients, AM colonization, root lengths, and hyphal length densities were determined. The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium. Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments, but shoot and root biomass of AM plants was depressed by P application. AM fungal inoculation decreased shoot As concentrations when no P was added, and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition, respectively. Shoot and root uptake of P, Mn, Cu, and Zn increased, but shoot Fe uptake decreased by 44.6%, with inoculation,when P was added. P addition reduced shoot P, Fe, Mn, Cu, and Zn uptake of AM plants, but increased root Fe and Mn uptake of the nonmycorrhizal ones. AM colonization therefore appeared to enhance plant tolerance to As in low P soil, and have some potential for the phytostabilization of As-contaminated soil, however, P application may introduce additional environmental risk by increasing soil As mobility.

  15. Arbuscular mycorrhiza of herbs colonizing a salt affected area near Kraków (Poland

    Directory of Open Access Journals (Sweden)

    Barbara Grzybowska

    2011-04-01

    Full Text Available The arbuscular mycorrhizal (AM status of plants colonizing an area affected by leakage of salty water (Barycz near Kraków, Poland was studied in 2000 and 2001. The occurrence of plants typical for soils of increased salinity was observed. Among the 13 examined plant species 7 were mycorrhizal. The abundance of mycorrhizal plant populations was increased in the second year of study. Strains of 4 species of AMF, including Glomus caledonium, G. claroideum, G. geosporum and G. intraradices were isolated using trap cultures. On the basis of morphological characters the presence of G. tenue was detected in plant roots of several species from the study area. The efficiency of mycorrhizal colonization and arbuscule formation by two strains of G. geosporum isolated from a saline area and a strain of G. intraradices from unaffected sites was tested in an experiment carried out on Plantago lanceolata cultivated on substrata of different salinity levels. The increase in mycorrhizal parameters with growing salt content was observed in the case of strains originating from the salt-affected area. At the highest salt level these strains formed better developed mycorrhiza than the strain from the non-saline site, suggesting a better adaptation of the strains from the saline area. The data on vitality (alkaline phosphatase test of intraradical AM fungi gave a clearer picture than those obtained by the conventional aniline blue staining.

  16. The roles of arbuscular mycorrhizal fungi (AMF) in phytoremediation and tree-herb interactions in Pb contaminated soil.

    Science.gov (United States)

    Yang, Yurong; Liang, Yan; Han, Xiaozhen; Chiu, Tsan-Yu; Ghosh, Amit; Chen, Hui; Tang, Ming

    2016-01-01

    Understanding the roles of arbuscular mycorrhizal fungi (AMF) in plant interaction is essential for optimizing plant distribution to restore degraded ecosystems. This study investigated the effects of AMF and the presence of legume or grass herbs on phytoremediation with a legume tree, Robinia pseudoacacia, in Pb polluted soil. In monoculture, mycorrhizal dependency of legumes was higher than that of grass, and AMF benefited the plant biomass of legumes but had no effect on grass. Mycorrhizal colonization of plant was enhanced by legume neighbors but inhibited by grass neighbor in co-culture system. N, P, S and Mg concentrations of mycorrhizal legumes were larger than these of non-mycorrhizal legumes. Legume herbs decreased soil pH and thereby increased the Pb concentrations of plants. The neighbor effects of legumes shifted from negative to positive with increasing Pb stress levels, whereas grass provided a negative effect on the growth of legume tree. AMF enhanced the competition but equalized growth of legume-legume under unpolluted and Pb stress conditions, respectively. In conclusion, (1) AMF mediate plant interaction through directly influencing plant biomass, and/or indirectly influencing plant photosynthesis, macronutrient acquisition, (2) legume tree inoculated with AMF and co-planted with legume herbs provides an effective way for Pb phytoremediation. PMID:26842958

  17. Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils.

    Science.gov (United States)

    Wu, Fuyong; Hu, Junli; Wu, Shengchun; Wong, Ming Hung

    2015-06-01

    A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p < 0.05) decreased As concentrations in husk, straw, and root in soils added with 70 mg kg(-1) As. The present results suggest that AM fungi are able to mitigate the adverse effects with enhancing rice production when growing in As-contaminated soils.

  18. Changes in arbuscular mycorrhizal associations and fine root traits in sites under different plant successional phases in southern Brazil.

    Science.gov (United States)

    Zangaro, Waldemar; de Assis, Rafael Leandro; Rostirola, Leila Vergal; de Souza, Priscila Bochi; Gonçalves, Melissa Camargo; Andrade, Galdino; Nogueira, Marco Antonio

    2008-12-01

    Fine root morphological traits and distribution, arbuscular mycorrhizal (AM) fungi, soil fertility, and nutrient concentration in fine root tissue were compared in sites under different successional phases: grass plants, secondary forest, and mature forest in Londrina county, Paraná state, southern Brazil. Soil cores were collected randomly at the 0-10- and 10-20-cm depths in three quadrants (50 m2) in each site. Plants from the different successional stages displayed high differences in fine root distribution, fine root traits, and mycorrhizal root colonization. There were increases in the concentration of nutrients both in soil and fine roots and decrease of bulk soil density along the succession. The fine root biomass and diameter increased with the succession progress. The total fine root length, specific root length, root hair length, and root hair incidence decreased with the succession advance. Similarly, the mycorrhizal root colonization and the density of AM fungi spores in the soil decreased along the succession. Mycorrhizal root colonization and spore density were positively correlated with fine root length, specific root length, root hair length, root hair incidence, and bulk density and negatively correlated with fine root diameter and concentration of some nutrients both in soil and root tissues. Nutrient concentration in root tissue and in soil was positively correlated with fine root diameter and negatively correlated with specific root length, root hair length, and root hair incidence. These results suggest different adaptation strategies of plant roots for soil exploration and mineral acquisition among the different successional stages. Early successional stages displayed plants with fine root morphology and AM fungi colonization to improve the root functional efficiencies for uptake of nutrients and faster soil resource exploration. Late successional stages displayed plants with fine root morphology and mycorrhizal symbiosis for both a lower

  19. The potential role of arbuscular mycorrhizal fungi in protecting endangered plants and habitats.

    Science.gov (United States)

    Bothe, Hermann; Turnau, Katarzyna; Regvar, Marjana

    2010-10-01

    Ecosystems worldwide are threatened with the extinction of plants and, at the same time, invasion by new species. Plant invasiveness and loss of species can be caused by similar but opposing pressures on the community structures. Arbuscular mycorrhizal fungi (AMF) can have multiple positive effects on plant growth, productivity, health, and stress relief. Many endangered species live in symbiosis with AMF. However, the list of the International Union for Conservation of Nature and Natural Resources (IUCN Red List of Threatened Species) indicates that the mycorrhizal status of most of the threatened species has not been assessed. Rare plants often occur in specialized and also endangered habitats and might utilize specialized or unique AMF. The specificity of any endangered plant to its AMF population has not been investigated. Because most of the current AMF isolates that are available colonize a broad range of plant species, selected inocula could be used to promote growth of endangered plants before the proper and more effective indigenous AMF are characterized. Application of AMF in field sites to protect endangered plants is hardly feasible due to the complexity of plant community structures and the large amount of fungal inocula needed. Endangered plants could, however, be grown as greenhouse cultures together with appropriate fungi, and, at the relevant developmental stage, they could be re-planted into native sites to prevent extinction and to preserve plant community ecology. PMID:20652364

  20. Diversity and zonal distribution of arbuscular mycorrhizal fungi on the northern slopes of the Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    SHI ZhaoYong; CHEN ZhiChao; ZHANG LiYun; FENG Gu; CHRISTIE Peter; TIAN ChangYan; LI XiaoLin

    2007-01-01

    The arbuscular mycorrhizal (AM) fungal status of the 20 most common plant species distributed in 4 vegetation types (meadow steppe, desert steppe, steppe desert and typical desert) on the northern slopes of the Tianshan Mountains was investigated. Samples of the plant species and their rhizosphere soils were collected from the 4 vegetation zones and examined to compare their mycorrhizal status, AM fungal spore densities, biovolumes, and community structures. 28 AM fungal species were isolated from the rhizosphere soils: of these, 5 belonged to Acaulospora, 1 to Archaeospora and 22 to Glomus.5 AM fungi, Glomus aggregatum, G. claroideum, G. deserticola, G. etunicatum and G. sinuosum, were observed in all 4 zonal types. No significant differences were observed in mean proportion of root length colonized by AM fungi among the plant species within each zonal type. Comparing the 4 zonal types, Plantago minuta (84.5%)in steppe desert and Eremopyrum orientale (83.1%) in typical desert showed the highest root colonizatsion rates. AM fungal spore densities and biovolumes were significantly different in the different zonal types. AM fungal spore d ensities and biovolumes, species richness and diversity were highest in meadow steppe and lowest in typical desert.

  1. Dynamics of phoxim residues in green onion and soil as influenced by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Wang, Fa Yuan; Shi, Zhao Yong; Tong, Rui Jian; Xu, Xiao Feng

    2011-01-15

    Organophosphorus pesticides in crops and soil pose a serious threat to public health and environment. Arbuscular mycorrhizal (AM) fungi may make a contribution to organophosphate degradation in soil and consequently decrease chemical residues in crops. A pot culture experiment was conducted to investigate the influences of Glomus caledonium 90036 and Acaulospora mellea ZZ on the dynamics of phoxim residues in green onion (Allium fistulosum L.) and soil at different harvest dates after phoxim application. Results show that mycorrhizal colonization rates of inoculated plants were higher than 70%. Shoot and root fresh weights did not vary with harvest dates but increased significantly in AM treatments. Phoxim residues in plants and soil decreased gradually with harvest dates, and markedly reduced in AM treatments. Kinetic analysis indicated that phoxim degradation in soil followed a first-order kinetic model. AM inoculation accelerated the degradation process and reduced the half-life. G. caledonium 90036 generally produced more pronounced effects than A. mellea ZZ on both the plant growth and phoxim residues in plants and soil. Our results indicate a promising potential of AM fungi for the control of organophosphate residues in vegetables, as well as for the phytoremediation of organophosphorus pesticide-contaminated soil. PMID:20870354

  2. Arbuscular mycorrhizal status of medicinal plants in Rajshahi University Campus%拉杰沙希大学校园药用植物菌根研究

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Forty different medicinal plants were investigated for arbuscular mycorrhizal association in the Rajshahi University Campus in Bangladesh.The results indicated that 35 different plants were infected by AM (arbuscular mycorrhizal)fungi as found by trypan blue staining procedure.The percentage of root colonization by AM fungi varied from 13.3% to 100%.Mangifera indica and Morus indica have maximum percentage of colonization(100%).The intensity of root colonization were abundant in the plants belonging to the families Anacardiaceae,Asclepiadaceae,Moraceae,Leguminosae and Apocynaceae whereas the intensity of colonization of crop roots were moderate and poor belonging to Gramineae and Leguminosae.The presence of greater number of spore in soil was always associated with the incidence of abundant mycelia.In plant roots the formation of spore and mycelia was restricted by low pH.Number of mycorrhizal fungus spores ranged between 35 to100 per 100g air dried soil in different family respective soils.The frequency of mycorrhizal fungus infection showed positive correlation with soil pH,moisture,water holding capacity,texture,total nitrogen,organic carbon,phosphorus,calcium,potassium,and magnesium.Especially phosphorus and nitrogen in the soil greatly influenced the plant root infection by AM fungi.

  3. Arbuscular Mycorrhizal Fungi and Biochar Improved Early Growth of Neem (Melia azedarach Linn. Seedling Under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Sri Wilarso Budi

    2013-08-01

    Full Text Available The objective of this research was to determine the effect of biochar on the seedling quality index and growth of neem tree seedlings and arbuscular mycorrhizal fungi (AMF development  grown on ultisol  soil medium.  Two factors in completely randomised experimental design was conducted under green house conditions and Duncan Multiple Range Test was used to analyse the data. The results showed that neem seedling quality index was improved by interaction of AMF fungi and biochar amandment. The growth of neem seedling was significantly increased by interactions of arbuscular mycorrhizal fungi and biochar.  The combination  treatment of Glomus etunicatum and biochar 10% gave best results of height and diameter, and significantly increased by 712% and 303% respectively, as compared to control plant, while the combination treatment of Gigaspora margarita and biochar 10% gave the best result of shoot dry weight, and root dry weight and significantly increase by 4,547% and 6,957% as compared to control plant.  The mycorrhizal root colonization was increased with increasing biochar added, but decreases when 15% of biochar was applied.  N, P, and K uptake of 12 weeks neem seedling old was higher and significantly increased as compared to control plant.Keywords: AMF development, nutrient uptake , plant growth , seedling quality index, biochar  DOI: 10.7226/jtfm.19.2.103

  4. Growth, Cadmium Accumulation and Physiology of Marigold (Tagetes erecta L.) as Affected by Arbuscular Mycorrhizal Fungi

    Institute of Scientific and Technical Information of China (English)

    LIU Ling-Zhi; GONG Zong-Qiang; ZHANG Yu-Long; LI Pei-Jun

    2011-01-01

    A pot experiment was carried out to study the effects of three arbuscular mycorrhizal fungi (AMF), including Glomus intraradices, Glomus constrictum and Glomus mosseae, on the growth, root colonization and Cd accumulation of marigold (Tagetes erecta L.) at Cd addition levels of 0, 5 and 50 mg kg-1 in soil. The physiological characteristics, such as chlorophyll content, soluble sugar content, soluble protein content and antioxidant enzyme activity, of Tagetes erecta L. were also investigated. The symbiotic relationship between the marigold plant and arbuscular mycorrhizal fungi was well established under Cd stress. The symbiotic relationship was reflected by the better physiobiochemical parameters of the marigold plants inoculated with the three AMF isolates where the colonization rates in the roots were between 34.3% and 88.8%. Compared with the non-inoculated marigold plants, the shoot and root biomass of the inoculated marigold plants increased by 15.2%-47.5% and 47.8%-130.1%, respectively, and the Cd concentration and accumulation decreased. The chlorophyll and soluble sugar contents in the mycorrhizal marigold plants increased with Cd addition, indicating that AMF inoculation helped the marigold plants to grow by resisting Cd stress. The antioxidant enzymes reacted differently with the three AMF under Cd stress. For plants inoculated with G. constrictum and G. mosseae, the activities of superoxide dismutase (SOD) and catalase (CAT) increased with increasing Cd addition, but peroxidase (POD) activity decreased with increasing Cd addition. For plants inoculated with G. intruradices, three of the antioxidant enzyme activities were significantly decreased at high levels of Cd addition. Overall, the activities of the three antioxidant enzymes in the plants inoculated with AMF were higher than those of the plants without AMF inoculation under Cd stress. Our results support the view that antioxidant enzymes have a great influence on the biomass of plants

  5. Arbuscular Mycorrhizal and Dark Septate Endophyte Fungal Associations in South Indian Aquatic and Wetland Macrophytes

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    Kumar Seerangan

    2014-01-01

    Full Text Available Investigations on the prevalence of arbuscular mycorrhizal (AM and dark septate endophyte (DSE fungal symbioses are limited for plants growing in tropical aquatic and wetland habitats compared to those growing on terrestrial moist or dry habitats. Therefore, we assessed the incidence of AM and DSE symbiosis in 8 hydrophytes and 50 wetland plants from four sites in south India. Of the 58 plant species examined, we found AM and DSE fungal symbiosis in 21 and five species, respectively. We reported for the first time AM and DSE fungal symbiosis in seven and five species, respectively. Intermediate-type AM morphology was common, and AM morphology is reported for the first time in 16 plant species. Both AM and DSE fungal colonization varied significantly across plant species and sites. Intact and identifiable AM fungal spores occurred in root zones of nine plant species, but AM fungal species richness was low. Though no clear relationship between AM and DSE fungal colonization was recognized, a significant negative correlation between AM colonization and spore numbers was established. Our study suggests that the occurrence of AM and DSE fungal symbiosis in plants growing in hydrophytic and wetland habitats is not as common as in terrestrial habitats.

  6. Do arbuscular mycorrhizal fungi affect arsenic accumulation and speciation in rice with different radial oxygen loss?

    Science.gov (United States)

    Li, H; Man, Y B; Ye, Z H; Wu, C; Wu, S C; Wong, M H

    2013-11-15

    The effects of arbuscular mycorrhizal fungi (AMF) on the temporal variation of arsenic (As) speciation and accumulation in two paddy rice cultivars (TD 71 and Xiushui 11) with different degrees of radial oxygen loss (ROL) at three growth periods (day 7, day 35, day 63 after flooding the soil) were investigated in soil, spiked with and without 30 mg As kg(-1). The results showed that TD 71 with high ROL colonized by Glomus intraradices led to higher root colonization rates than Xiushui 11 at three growth periods, both in soil with or without 30 mg As kg(-1) (pcontaminated flooding soils. Furthermore, the ratios of As(III) conc./As(V) conc. in roots of TD71 were significantly more than Xiushui 11 when colonized by AMF at three growth periods in 30 mg As kg(-1) soil (price with high ROL can favor AM fungal infection and enhance root ratio of As(III) conc./As(V) conc. in the presence of AMF. PMID:22673057

  7. Morphotype-based characterization of arbuscular mycorrhizal fungal communities in a restored tropical dry forest, Margarita island-Venezuela.

    Science.gov (United States)

    Fajardo, Laurie; Loveral, Milagros; Arrindell, Pauline; Aguilar, Victor Hugo; Hasmy, Zamira; Cuenca, Gisela

    2015-09-01

    The mycorrhizal component of revegetated areas after ecological restoration or rehabilitation in arid and semiarid tropical areas has been scarcely assessed, particularly those made after mining disturbance. We evaluated and compared the presence of arbuscular mycorrhizal fungi of a small area of restored tropical dry forest destroyed by sand extraction, with a non-restored area of similar age, at the peninsula of Macanao, Margarita Island (Venezuela). Our study was undertaken in 2009, four years after planting, and the mycorrhizal status was evaluated in four restored plots (8 x 12.5 m) (two were previously treated with hydrogel (R2 and R2'), and two were left untreated (R1 and R1'), and four non-restored plots of similar size (NR1 and NR1' with graminoid physiognomy with some scattered shrubs; and NR2 and NR2', with a more species rich plant community). Apparently the restoration management promoted higher arbuscular mycorrhizal fungi (AMF) species richness and diversity, particularly in restored soils where the hydrogel was added (R2 treatment). Soil of the NRI treatment (with a higher herbaceous component) showed the highest spore density, compared to samples of soils under the other treatments. Considering species composition, Claroideoglomus etunicatum and Rhizophagus intraradices were found in all treatments; besides, Diversispora spurca and Funnefformis geosporum were only found in non-restored plots, while members of the Gigasporaceae (a family associated with little disturbed sites) were commonly observed in the plots with restored soils. Mycorrhizal colonization was similar in the restored and non-restored areas, being a less sensitive indicator of the ecosystem recovery. The trend of higher richness and diversity of AMF in the restored plot with hydrogel suggests that this management strategy contributes to accelerate the natural regeneration in those ecosystems where water plays an essential role. PMID:26666138

  8. Arbuscular mycorrhizal fungal communities are phylogenetically clustered at small scales.

    Science.gov (United States)

    Horn, Sebastian; Caruso, Tancredi; Verbruggen, Erik; Rillig, Matthias C; Hempel, Stefan

    2014-11-01

    Next-generation sequencing technologies with markers covering the full Glomeromycota phylum were used to uncover phylogenetic community structure of arbuscular mycorrhizal fungi (AMF) associated with Festuca brevipila. The study system was a semi-arid grassland with high plant diversity and a steep environmental gradient in pH, C, N, P and soil water content. The AMF community in roots and rhizosphere soil were analyzed separately and consisted of 74 distinct operational taxonomic units (OTUs) in total. Community-level variance partitioning showed that the role of environmental factors in determining AM species composition was marginal when controlling for spatial autocorrelation at multiple scales. Instead, phylogenetic distance and spatial distance were major correlates of AMF communities: OTUs that were more closely related (and which therefore may have similar traits) were more likely to co-occur. This pattern was insensitive to phylogenetic sampling breadth. Given the minor effects of the environment, we propose that at small scales closely related AMF positively associate through biotic factors such as plant-AMF filtering and interactions within the soil biota.

  9. Soil characteristics driving arbuscular mycorrhizal fungi communities in semiarid soils

    Science.gov (United States)

    Torrecillas, Emma; del Mar Alguacil, Maria; Torres, Pilar; Díaz, Gisela; Caravaca, Fuensanta; Montesinos, Alicia; Roldán, Antonio

    2014-05-01

    Arbuscular mycorrhizal fungi (AMF) are an important soil microbial group that affects multiple ecosystems functions and processes, including nutrient cycling, plant productivity and competition, and plant diversity. We carried out a study to investigate AMF communities in the roots and the rhizosphere of Brachypodium retusum (Pers.) Beauv., a common plant species of great ecological importance that grows in different type of soils in semiarid Mediterranean areas with similar climatic conditions. We hypothesized that if both factors, host plant species and climatic conditions, cannot influence the differences in AMF communities in the roots and in the rhizosphere of Brachypodium retusum, variances in AMF richness and diversity could be due to soil characteristics. Hence we study the relationships between physical, chemical and biological soil characteristics and AMF community composition found in the roots and in the rhizospheres. We recorded sixty-seven AMF operational taxonomical units (OTUs). Each soil type presented a different AMF community composition and thus, can be characterized by its own AMF communities. A combination among some of the soil parameters could define the AMF species present in the roots and the rhizosphere of B. retusum. It was the case for calcium, urease, protease and ß-glucosidase which explained the variation in the AMF communities. In conclusion, soil charactristics can be decisive in the assembling of the AMF communities, managing the diversity and composition of these communities.

  10. Augmented growth of long pepper in response to arbuscular mycorrhizal inoculation

    Institute of Scientific and Technical Information of China (English)

    R.K.Singh; P.Gogoi

    2012-01-01

    Arbuscular mycorrhizal (AM) technology is a soil-based fertilization practice for sustainable crop productivity.We evaluated six indigenous Arbuscular mycorrhizal fungi (AMF) strains for their symbiotic response with Piper longum (long pepper),a non-timber forest product holding promise as a commercial crop for its medicinal fruits and roots.Piper saplings were raised in a 10 cm thick sand and soil mix inoculated with various AMF.Under field conditions,plants inoculated with AMF demonstrated better survival (≥80%) than non mycorrhizal plants (58%).Almost all the studied AMF strains increased the plant growth,biomass and nutrient content (N and P) over the uninoculated control.Mycorrhizal inoculation with four AMF species,viz:Glomus fasciculatum,G.clarum,G.etunicatum and G.versiforme greatly enhanced long pepper growth both in the nursery and field conditions.

  11. Symbiosis of Arbuscular Mycorrhizal Fungi and Robinia pseudoacacia L. Improves Root Tensile Strength and Soil Aggregate Stability.

    Directory of Open Access Journals (Sweden)

    Haoqiang Zhang

    Full Text Available Robinia pseudoacacia L. (black locust is a widely planted tree species on Loess Plateau for revegetation. Due to its symbiosis forming capability with arbuscular mycorrhizal (AM fungi, we explored the influence of arbuscular mycorrhizal fungi on plant biomass, root morphology, root tensile strength and soil aggregate stability in a pot experiment. We inoculated R. pseudoacacia with/without AM fungus (Rhizophagus irregularis or Glomus versiforme, and measured root colonization, plant growth, root morphological characters, root tensile force and tensile strength, and parameters for soil aggregate stability at twelve weeks after inoculation. AM fungi colonized more than 70% plant root, significantly improved plant growth. Meanwhile, AM fungi elevated root morphological parameters, root tensile force, root tensile strength, Glomalin-related soil protein (GRSP content in soil, and parameters for soil aggregate stability such as water stable aggregate (WSA, mean weight diameter (MWD and geometric mean diameter (GMD. Root length was highly correlated with WSA, MWD and GMD, while hyphae length was highly correlated with GRSP content. The improved R. pseudoacacia growth, root tensile strength and soil aggregate stability indicated that AM fungi could accelerate soil fixation and stabilization with R. pseudoacacia, and its function in revegetation on Loess Plateau deserves more attention.

  12. Transcriptomes of arbuscular mycorrhizal fungi and litchi host interaction after tree girdling

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    Bo eShu

    2016-03-01

    Full Text Available Trunk girdling can increase carbohydrate content above the girdling site and is an important strategy for inhibiting new shoot growth to promote flowering in cultivated litchi (Litchi chinenis Sonn.. However, girdling inhibits carbohydrate transport to the root in nearly all of the fruit development periods and consequently decreases root absorption. The mechanism through which carbohydrates regulate root development in arbuscular mycorrhiza (AM remains largely unknown. Carbohydrate content, AM colonization, and transcriptome in the roots were analyzed to elucidate the interaction between host litchi and AM fungi when carbohydrate content decreases. Girdling decreased glucose, fructose, sucrose, quebrachitol and starch contents in the litchi mycorrhizal roots, thereby reducing AM colonization. RNA-seq achieved approximately 60 million reads of each sample, with an average length of reads reaching 100 bp. Assembly of all the reads of the 30 samples produced 671,316 transcripts and 381,429 unigenes, with average lengths of 780 and 643 bp, respectively. Litchi (54,100 unigenes and AM fungi unigenes (33,120 unigenes were achieved through sequence annotation during decreased carbohydrate content. Analysis of differentially expressed genes (DEG showed that flavonoids, alpha-linolenic acid, and linoleic acid are the main factors that regulate AM colonization in litchi. However, flavonoids may play a role in detecting the stage at which carbohydrate content decreases; alpha-linolenic acid or linoleic acid may affect AM formation under the adaptation process. Litchi trees stimulated the expression of defense-related genes and downregulated symbiosis signal-transduction genes to inhibit new AM colonization. Moreover, transcription factors of the AP2, ERF, Myb, WRKY, bHLH families, and lectin genes altered maintenance of litchi mycorrhizal roots in the post-symbiotic stage for carbohydrate starvation. Similar to those of the litchi host, the E3 ubiquitin

  13. Micorrizas arbusculares del tipo 'Arum' y 'Paris' y endófitos radicales septados oscuros en Miconia ioneura y Tibouchina paratropica (Melastomataceae 'Arum' and 'Paris' arbuscular mycorrhizal types and dark septate root endophytes in Miconia ioneura and Tibouchina paratropica (Melastomataceae

    Directory of Open Access Journals (Sweden)

    Carlos Urcelay

    2005-12-01

    Full Text Available Se estudió la colonización de las raíces por simbiontes fúngicos en Miconia ioneura y Tibouchina paratropica (Melastomataceae. Se observaron y describen estructuras micorrícicas arbusculares pertenecientes a los tipos 'Paris' (hifas y rulos intracelulares y 'Arum' (hifas intercelulares y arbúsculos. Además se observaron endófitos septados oscuros (hifas y esclerocios. Se registra por primera vez la ocurrencia de ambos tipos micorrícicos arbusculares y de endófitos septados oscuros en raíces de especies pertenecientes a la familia Melastomataceae. Se discuten las implicancias ecológicas y evolutivas de la ocurrencia simultánea de los distintos tipos de colonización micorrícica en raíces de la misma especie.The roots of Miconia ioneura and Tibouchina paratropica (Melastomataceae were studied for fungal symbionts colonization. Typical structures of 'Paris' (intracellular hyphae and coils and 'Arum' (intercellular hyphae and arbuscules arbuscular mycorrhizal types were observed and are described here. Dark septate fungi (hyphae and sclerotia were also observed. The occurrence of both types of arbuscular mycorrhizal colonisation and dark septate fungi in the roots of species belonging to Melastomataceae is reported for the first time. The possible ecological and evolutionary implications of the co-occurrence of these mycorrhizal colonisation types in the same species are discussed.

  14. Associations of dominant plant species with arbuscular mycorrhizal fungi during vegetation development on coal mine spoil banks

    Energy Technology Data Exchange (ETDEWEB)

    Rydlova, J.; Vosatka, M. [Academy of Science. Pruhonice (Czech Republic). Inst. of Botany

    2001-07-01

    Among plants colonizing mine spoil banks in Northern Bohemia the first colonizers, mainly ruderal annuals from Chenopodiaceae and Brassicaceae were found not to be associated with arbuscular mycorrhizal fungi (AMF). These species cultivated in pots with soil from four sites in different succession stages of the spoil bank did not respond to the presence of native or non-native AMF. All grass species studied (Elytrigia repens, Calamagrostis epigejos and Arrhenatherum elatius) were found moderately colonized in the field. Carduus acanthoides was found to be highly colonized in the field; however, it did not show growth response to AMF in the pot experiment. The AMF native in four sites on the spoil banks showed high infectivity but low effectiveness in association with colonizing plants compared to the non-native isolate G. fistulosum BEG23. In general, dependence on AMF in the cultivation experiment was rather low, regardless of the fact that plants were found to be associated with AMF either in the field or in pots. Occurrence and effectiveness of mycorrhizal associations might relate primarily to the mycotrophic status of each plant species rather than to the age of the spoil bank sites studied.

  15. Arbuscular mycorrhizal fungal diversity in the Tuber melanosporum brûlé.

    Science.gov (United States)

    Mello, Antonietta; Lumini, Erica; Napoli, Chiara; Bianciotto, Valeria; Bonfante, Paola

    2015-06-01

    The development of the fruiting body (truffle) of the ectomycorrhizal fungus Tuber melanosporum is associated with the production of an area (commonly referred to with the French word brûlé) around its symbiotic plant that has scanty vegetation. As truffles produce metabolites that can mediate fungal-plant interactions, the authors wondered whether the brûlé could affect the arbuscular mycorrhizal fungi (AMF) that colonize the patchy herbaceous plants inside the brûlé. A morphological evaluation of the roots of plants collected in 2009 from a T. melanosporum/Quercus pubescens brûlé in France has shown that the herbaceous plants are colonized by AMF to a great extent. An analysis of the 18S rRNA sequences obtained from roots and soil inside the brûlé has shown that the AMF community structure seemed to be affected in the soil inside the brûlé, where less richness was observed compared to outside the brûlé. PMID:25986549

  16. Do arbuscular mycorrhizal fungi affect cadmium uptake kinetics, subcellular distribution and chemical forms in rice?

    Science.gov (United States)

    Li, Hui; Luo, Na; Zhang, Li Jun; Zhao, Hai Ming; Li, Yan Wen; Cai, Quan Ying; Wong, Ming Hung; Mo, Ce Hui

    2016-11-15

    Rice (Oryza sativa L.) plants were inoculated with two species of arbuscular mycorrhizal fungi (AMF) - Rhizophagus intraradices (RI) and Funneliformis mosseae (FM) and grown for 60days to ensure strong colonization. Subsequently, a short-term hydroponic experiment was carried out to investigate the effects of AMF on cadmium (Cd) uptake kinetics, subcellular distribution and chemical forms in rice exposed to six Cd levels (0, 0.005, 0.01, 0.025, 0.05, 0.1mM) for three days. The results showed that the uptake kinetics of Cd fitted the Michaelis-Menten model well (R(2)>0.89). AMF significantly decreased the Cd concentrations both in shoots and roots in Cd solutions. Furthermore, the decrement of Cd concentrations by FM was significantly higher than RI treatment in roots. AMF reduced the Cd concentrations markedly in the cell wall fractions at high Cd substrate (≥0.025mM). The main subcellular fraction contributed to Cd detoxification was cell wall at low Cd substrate (AMF colonization at high Cd substrate (≥0.05mM), both in shoots and roots. This suggested that AMF could convert Cd into inactive forms which were less toxic. Therefore, AMF could enhance rice resistance to Cd through altering subcellular distribution and chemical forms of Cd in rice. PMID:27450963

  17. Arbuscular mycorrhizal fungi associated with Populus-Salix stands in a semiarid riparian ecosystem

    Science.gov (United States)

    Beauchamp, Vanessa B.; Stromberg, J.C.; Stutz, J.C.

    2006-01-01

    ??? This study examined the activity, species richness, and species composition of the arbuscular mycorrhizal fungal (AMF) community of Populus-Salix stands on the Verde River (Arizona, USA), quantified patterns of AMF richness and colonization along complex floodplain gradients, and identified environmental variables responsible for structuring the AMF community. ??? Samples from 61 Populus-Salix stands were analyzed for AMF and herbaceous composition, AMF colonization, gravimetric soil moisture, soil texture, per cent organic matter, pH, and concentrations of nitrate, bicarbonate phosphorus and exchangeable potassium. ??? AMF species richness declined with stand age and distance from and elevation above the channel and was positively related to perennial species cover and richness and gravimetric soil moisture. Distance from and elevation above the active channel, forest age, annual species cover, perennial species richness, and exchangeable potassium concentration all played a role in structuring the AMF community in this riparian area. ??? Most AMF species were found across a wide range of soil conditions, but a subset of species tended to occur more often in hydric areas. This group of riparian affiliate AMF species includes several not previously encountered in the surrounding Sonoran desert. ?? New Phytologist (2006).

  18. Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosano, Edmilson Jose; Rossi, Fabricio; Guirado, Nivaldo; Teramoto, Juliana Rolim Salome [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Piracicaba, SP (Brazil). Polo Regional Centro Sul; Azcon, Rozario [Consejo Superior de Investigaciones Cientificas (CSIC), Granada (Spain). Estacao Experimental de Zaidin; Cantarela, Heitor [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Solos e Recursos Ambientais; Ambrosano, Glaucia Maria Bovi [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Odontologia Social], Email: ambrosano@apta.sp.gov.br; Schammass, Eliana Aparecida [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IZ), Nova Odessa, SP (Brazil). Inst. de Zootecnia; Muraoka, Takashi; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Ungaro, Maria Regina Goncalves [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Plantas Graniferas

    2010-07-01

    Sugarcane (Saccharum spp.) is an important crop for sugar production and agro-energy purposes in Brazil. In the sugarcane production system after a 4- to 8-year cycle crop rotation may be used before replanting sugarcane to improve soil conditions and give an extra income. This study had the objective of characterizing the biomass and the natural colonization of arbuscular mycorrhizal fungi (AMF) of leguminous green manure and sunflower (Helianthus annuus L.) in rotation with sugarcane. Their effect on stalk and sugar yield of sugarcane cv. IAC 87-3396 grown subsequently was also studied. Cane yield was harvested in three subsequent cuttings. Peanut cv. IAC-Caiapo, sunflower cv. IAC-Uruguai and velvet bean (Mucuna aterrimum Piper and Tracy) were the rotational crops that resulted in the greater percentage of AMF. Sunflower was the specie that most extracted nutrients from the soil, followed by peanut cv. IAC-Tatu and mung bean (Vigna radiata L. Wilczek). The colonization with AMF had a positive correlation with sugarcane plant height, at the first cut (p = 0.01 and R = 0.52) but not with the stalk or cane yields. Sunflower was the rotational crop that brought about the greatest yield increase of the subsequent sugarcane crop: 46% increase in stalk yield and 50% in sugar yield compared with the control. Except for both peanut varieties, all rotational crops caused an increase in net income of the cropping system in the average of three sugarcane harvests. (author)

  19. Arbuscular mycorrhizal status of wild plants in saline-alkaline soils of the Yellow River Delta.

    Science.gov (United States)

    Wang, Fa-Yuan; Liu, Run-Jin; Lin, Xian-Gui; Zhou, Jian-Min

    2004-04-01

    A survey was made of the arbuscular mycorrhizal (AM) status of five dominant wild plants Tamarix chinensis, Phragmites communis, Suaeda glauca, Aeluropus littoralis var. sinensis and Cirsium setosum in saline-alkaline soils of the Yellow River Delta that show low plant diversity. All of the species were colonized and showed typical AM structures (arbuscules, vesicles). The colonization percentage ranged from 0.2% to 9.5%, where C. setosum was the highest. The species richness of AMF at the different sites ranged from 2.00 to 2.40 per 50 ml soil, with an average of 2.16. Species diversity ranged from 1.99 to 2.22 per 50 ml soil, with an average of 2.13. Spore density ranged from 3 to 30 per 50 ml soil, with an average of 12. Glomus was the dominant genus, with a frequency and relative abundance of 88.1% and 68.4%, respectively. G. caledonium, with a frequency and relative abundance of 15.0% and 4.6%, respectively, was the dominant species. Differences were also observed in the distribution of AMF in different soil layers. Although there were still AM fungal spores in the layer 40 cm below the surface, most spores were found at a depth of 0-40 cm.

  20. The ecology of arbuscular-mycorrhizal fungi (AMF) under different cropping regimes

    International Nuclear Information System (INIS)

    The ecology of Arbuscular Mycorrhizal Fungi (AMF) in mono-cropping and low-input ideal agroforestry cropping systems of Avena sativa has been studied. Soil chemical heterogeneity, seasonality and nature of cropping system showed significant attributes on AMF. AMF percentage in roots and spore populations in soil were elevated in dry season compared to wet season. With respect to cropping regimes, mono-cropping systems exhibited highest root infection whereas the agroforestry systems possessed highest AM fungal spore populations. Generally, farming systems tested here possessed significant colonization of AMF, however, overall extent of colonization and spore densities were low. While assessing the correlation between soil chemical composition and AMF, electrical conductivity, organic carbon content, available potassium and saturation percentage showed a negative correlation. However, pH showed a positive correlation and available phosphorus content showed no correlation with AMF. Present study was aimed to view the importance of agroforestry in modern agriculture and normal agricultural system and the benefits associated with AM fungi. (author)

  1. Arbuscular mycorrhizal fungi in Mimosa tenuiflora (Willd.) Poir from Brazilian semi-arid.

    Science.gov (United States)

    de Souza, Tancredo Augusto Feitosa; Rodriguez-Echeverría, Susana; de Andrade, Leonaldo Alves; Freitas, Helena

    2016-01-01

    Many plant species from Brazilian semi-arid present arbuscular mycorrhizal fungi (AMF) in their rhizosphere. These microorganisms play a key role in the establishment, growth, survival of plants and protection against drought, pathogenic fungi and nematodes. This study presents a quantitative analysis of the AMF species associated with Mimosa tenuiflora, an important native plant of the Caatinga flora. AMF diversity, spore abundance and root colonization were estimated in seven sampling locations in the Ceará and Paraíba States, during September of 2012. There were significant differences in soil properties, spore abundance, percentage of root colonization, and AMF diversity among sites. Altogether, 18 AMF species were identified, and spores of the genera Acaulospora, Claroideoglomus, Dentiscutata, Entrophospora, Funneliformis, Gigaspora, Glomus, Racocetra, Rhizoglomus and Scutellospora were observed. AMF species diversity and their spore abundance found in M. tenuiflora rhizosphere shown that this native plant species is an important host plant to AMF communities from Brazilian semi-arid region. We concluded that: (a) during the dry period and in semi-arid conditions, there is a high spore production in M. tenuiflora root zone; and (b) soil properties, as soil pH and available phosphorous, affect AMF species diversity, thus constituting key factors for the similarity/dissimilarity of AMF communities in the M. tenuiflora root zone among sites. PMID:26991277

  2. Spore development and nuclear inheritance in arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Hijri Mohamed

    2011-02-01

    Full Text Available Abstract Background A conventional tenet of classical genetics is that progeny inherit half their genome from each parent in sexual reproduction instead of the complete genome transferred to each daughter during asexual reproduction. The transmission of hereditary characteristics from parents to their offspring is therefore predictable, although several exceptions are known. Heredity in microorganisms, however, can be very complex, and even unknown as is the case for coenocytic organisms such as Arbuscular Mycorrhizal Fungi (AMF. This group of fungi are plant-root symbionts, ubiquitous in most ecosystems, which reproduce asexually via multinucleate spores for which sexuality has not yet been observed. Results We examined the number of nuclei per spore of four AMF taxa using high Z-resolution live confocal microscopy and found that the number of nuclei was correlated with spore diameter. We show that AMF have the ability, through the establishment of new symbioses, to pass hundreds of nuclei to subsequent generations of multinucleated spores. More importantly, we observed surprising heterogeneity in the number of nuclei among sister spores and show that massive nuclear migration and mitosis are the mechanisms by which AMF spores are formed. We followed spore development of Glomus irregulare from hyphal swelling to spore maturity and found that the spores reached mature size within 30 to 60 days, and that the number of nuclei per spores increased over time. Conclusions We conclude that the spores used for dispersal of AMF contain nuclei with two origins, those that migrate into the spore and those that arise by mitosis in the spore. Therefore, these spores do not represent a stage in the life cycle with a single nucleus, raising the possibility that AMF, unlike all other known eukaryotic organisms, lack the genetic bottleneck of a single-nucleus stage.

  3. Arbuscular mycorrhizal fungi (Glomeromycota of the Vistula Bar

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2014-08-01

    Full Text Available The occurrence of arbuscular mycorrhizal fungi (AMF of the, phylum Glomeromycota associated with plants of maritime sand dunes of the Vistula Bar localed in north-eastern Poland was investigated. The presence of AMF was revealed based on spores isolated from field-collected root-rhizosphere soil mixtures and two-cycle pot trap cultures established with parts of these mixtures. The mixtures came from under five species in four plant families. Spores of AMF occurred in 54.8% of the field samples and belonged to eight species. Additionally, culturing of root-soil mixtures in trap cultures revealed nine species and three undescribed morphotypes carlier not found in the field samples. Considering the number of records of species and morphotypes in the field samples and trap cultures, the fungal species most frequently occurring in dunes of the Vistula Bar is Scutellospora dipurpurescens, followed by Archaeospora trappei, Glomus laccatum, and Scu. armeniaca. The overall average spore abundance in the field samples is low (4.48, range O-3l in 100g dry soil. The ovcrall average species richness determined based on spores from both the field and trap cultures was 2 l and ranged from 0 lo 7 in 100g dry soil. The plant harbouring the highest number of species of AMF was Festuca rubra. Of the maritime dune sites of Poland examined to date, the species composition of AMF of the Vistula Bar is most similar to that of the Słowiński National Park. When the comparisons included 15 maritime dune areas located outside Poland, the highest similarity occurred in the Vistula Bar/Canada comparison.

  4. Comparison of communities of arbuscular mycorrhizal fungi in roots of two Viola species

    DEFF Research Database (Denmark)

    Opik, M; Moora, Mari; Liira, Jaan;

    2006-01-01

    The composition of arbuscular mycorrhizal (AM) fungal communities in roots of rare Viola elatior and common V. mirabilis was investigated using PCR with primers specific for Glomus and common was investigated using PCR with primers specific for group A, followed by single-stranded conformation po...

  5. The effect of turf cutting on plant and arbuscular mycorrhizal spore recolonisation: Implications for heathland restoration

    NARCIS (Netherlands)

    Vergeer, P.; Berg, van den L.J.L.; Baar, J.; Ouborg, N.J.; Roelofs, J.G.M.

    2006-01-01

    In two natural heathland vegetations, we analysed the effect of turf cutting on spore numbers of arbuscular mycorrhizal fungi (AMF). Next to this, we performed a controlled factorial experiment to examine the role of AMF for germination and establishment of Arnica montana in both turf cut and non-tu

  6. Glomus eburneum and Scutellospora fulgida, species of arbuscular mycorrhizal fungi (Glomeromycota new for Europe

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2013-12-01

    Full Text Available Morphological characters of spores and mycorrhizae of Glomus eburneum and spores of Scutellospora fulgida, arbuscular mycorrhizal fungi of the phylum Glomeromycota, are described and illustrated. Additionally, the known distribution of these species in both Poland and other regions of the world is presented. Both species were not earlier reported from Europe.

  7. Community structure of arbuscular mycorrhizal fungi in undisturbed vegetation revealed by analyses of LSU rdna sequences

    DEFF Research Database (Denmark)

    Rosendahl, Søren; Holtgrewe-Stukenbrock, Eva

    2004-01-01

    Arbuscular mycorrhizal fungi (AMF) form a mutualistic symbiosis with plant roots and are found in most ecosystems. In this study the community structure of AMF in a clade of the genus Glomus was examined in undisturbed costal grassland using LSU rDNA sequences amplified from roots of Hieracium pi...

  8. Protocol: using virus-induced gene silencing to study the arbuscular mycorrhizal symbiosis in Pisum sativum

    DEFF Research Database (Denmark)

    Grønlund, Mette; Olsen, Anne; Johansen, Elisabeth;

    2010-01-01

    , the available PEBV-VIGS protocols are inadequate for studying genes involved in the symbiosis with arbuscular mycorrhizal fungi (AMF). Here we describe a PEBV-VIGS protocol suitable for reverse genetics studies in pea of genes involved in the symbiosis with AMF and show its effectiveness in silencing genes...... involved in the early and late stages of AMF symbiosis....

  9. Arbuscular Mycorrhizal Fungus Alleviates Chilling Stress by Boosting Redox Poise and Antioxidant Potential of Tomato Seedlings

    NARCIS (Netherlands)

    Liu, Airong; Chen, Shuangchen; Wang, Mengmeng; Liu, Dilin; Chang, Rui; Wang, Zhonghong; Lin, Xiaomin; Bai, Bing; Ahammed, Golam Jalal

    2016-01-01

    The universal symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plant roots remarkably stimulate plant growth, nutrient uptake, and stress responses. The present study investigated the stress ameliorative potential of the AM fungus Funneliformis mosseae against chilling in tom

  10. Taxon-specific PCR primers to detect two inconspicuous arbuscular mycorrhizal fungi from temperate agricultural grassland

    NARCIS (Netherlands)

    Gamper, H.A.; Leuchtmann, A.

    2007-01-01

    Taxon-specific polymerase chain reaction (PCR) primers enable detection of arbuscular mycorrhizal fungi (AMF, Glomeromycota) in plant roots where the fungi lack discriminative morphological and biochemical characters. We designed and validated pairs of new PCR primers targeted to the flanking region

  11. Community analysis of arbuscular mycorrhizal fungi associated with Ammophila arenaria in Dutch coastal sand dunes

    NARCIS (Netherlands)

    Kowalchuk, G.A.; De Souza, F.A.; Van Veen, J.A.

    2002-01-01

    A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) approach for the detection and characterization of arbuscular mycorrhizal fungi (AMF) 18S ribosomal DNA (rDNA) was developed and applied to the study of AMF communities associated with the main sand-stabilizing plant spec

  12. Arbuscular mycorrhizal symbiosis induces strigolactone biosynthesis under drought and improves drought tolerance in lettuce and tomato

    NARCIS (Netherlands)

    Ruiz-Lozano, J.M.; Aroca, R.; Zamarreno, A.M.; Molina, S.; Andreo Jimenez, B.; Porcel, R.; Garcia-Mina, J.M.; Ruyter-Spira, C.P.; Lopez-Raez, J.A.

    2015-01-01

    Arbuscular mycorrhizal (AM) symbiosis alleviates drought stress in plants. However, the intimate mechanisms involved, as well as its effect on the production of signalling molecules associated with the host plant–AM fungus interaction remains largely unknown. In the present work, the effects of drou

  13. Biology, ecology and evolution of the family Gigasporaceae, arbuscular mycorrhizal fungi (Glomeromycota)

    NARCIS (Netherlands)

    Souza, Francisco Adriano de

    2005-01-01

    Research described in this thesis focused on biological, ecological and evolutionary aspects of Arbuscular Mycorrhizal Fungi (AMF), and in particular of the family Gigasporaceae (Gigaspora and Scutellospora, genera). This study had two major objectives. The first objective was to obtain better knowl

  14. Application of arbuscular mycorrhizal fungi on the production of cut flower roses under commercial-like conditions

    Energy Technology Data Exchange (ETDEWEB)

    Garmendia, I.; Mangas, V. J.

    2012-11-01

    The objective of this work was to study the influence of two arbuscular mycorrhizal fungi (AMF) Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and G. intraradices (Schenck and Smith) on cut flower yield of rose (Rosa hybrida L. cv. Grand Gala) under commercial-like greenhouse conditions. Flower production was positively influenced by G. mosseae inoculation. Both inocula tested caused low levels of mycorrhizal root colonization, with higher percentages in Rosa associated with G. mosseae. Significant improvement of plant biomass, leaf nutritional status or flower quality was not detected in inoculated plants probably due to the low symbiosis establishment. However, G. mosseae reduced by one month the time needed for 80% of the plants to flower and slightly increased number of cut flowers relative to non-mycorrhizal controls on the fourth, sixth and eighth months after transplanting. It is suggested that an altered carbohydrate metabolism could contribute to this positive effect. Low colonization of rose roots supports the idea that more effort is required to ensure successful application of AMF in ornamental production systems. (Author) 40 refs.

  15. Effect of Various Organic Matter stimulates Bacteria and Arbuscular Mycorrhizal Fungi Plantations on Eroded Slopes in Nepal

    Science.gov (United States)

    Shrestha Vaidya, G.; Shrestha, K.; Wallander, H.

    2009-04-01

    Erosion resulting from landslides is a serious problem in mountainous countries such as Nepal. To restore such sites it is essential to establish plant cover that protects the soil and reduces erosion. Trees and shrubs on the lower hillsides in Nepal form symbiosis with arbuscular mycorrhizal (AM) fungi and these fungi are important for the uptake of mineral nutrients from the soil. In addition, the mycelia formed by these fungi have an important function in stabilizing the soil. The success of plantations of these eroded slopes is therefore highly dependent on the extent of mycorrhizal colonization of the plants. Mycorrhizal fungi growing in symbiosis with plants are essential in this respect because they improve both plant and nutrient uptake and soil structure. We investigated the influence of organic matter and P amendment on recently produced biomass of bacteria and arbuscular mycorrhizal (AM) fungi in eroded slopes in Nepal. Eroded soil mixed with different types of organic matter was placed in mesh bags which were buried around the trees of Bauhinia purpurea and Leucaena diversifolia .This experiment were done in two seasons ( (the wet and the dry season). Signature fatty acids were used to determine bacterial and AM fungal biomass after the six month intervals. The amount and composition of AM fungal spores were analyzed in the mesh bags from the wet and dry seasons. More microbial biomass was produced during wet season than during dry season. Further more, organic matter addition enhanced the production of AM fungal and bacterial biomass during both seasons. The positive influence of organic matter addition on AM fungi could be an important contribution to plant survival, growth and nutrient composition in the soil in plantations on eroded slopes. Different AM spore communities and bacterial profiles were obtained with different organic amendments and this suggests a possible way of selecting for specific microbial communities in the management of eroded

  16. Effect of different arbuscular mycorrhizal fungi on growth and physiology of maize at ambient and low temperature regimes

    DEFF Research Database (Denmark)

    Chen, Xiaoying; Song, Fengbin; Liu, Fulai;

    2014-01-01

    The effect of four different arbuscular mycorrhizal fungi (AMF) on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled...... with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM...... colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde...

  17. In Winter Wheat, No-Till Increases Mycorrhizal Colonization thus Reducing the Need for Nitrogen Fertilization

    Directory of Open Access Journals (Sweden)

    Julien Verzeaux

    2016-06-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF play a major role in the uptake of nutrients by agricultural plants. Nevertheless, some agricultural practices can interrupt fungal-plant signaling and thus impede the establishment of the mycorrhizal symbiosis. A field experiment performed over a 5-year period demonstrated that both the absence of tillage and of nitrogen (N fertilization improved AMF colonization of wheat roots. Moreover, under no-till conditions, N uptake and aboveground biomass production did not vary significantly between N-fertilized and N-unfertilized plots. In contrast, both N uptake and above ground biomass were much lower when N fertilizer was not added during conventional tillage. This finding strongly suggests that for wheat, no-till farming is a sustainable agricultural system that allows a gradual reduction in N fertilizer use by promoting AMF functionality and at the same time increasing N uptake.

  18. Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Ye, Z.H. [State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Chan, W.F.; Chen, X.W.; Wu, F.Y. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Wu, S.C. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China); Wong, M.H., E-mail: mhwong@hkbu.edu.hk [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China)

    2011-10-15

    The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg{sup -1}. In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses. - Highlights: > Rice/AMF combinations had significant effects on grain As concentration, grain yield and grain P uptake. > Rice colonized with suitable AMF can increase grain yield. > The variation in the transfer and uptake of As and P reflected strong functional diversity in AM symbioses. - Different rice/AMF combinations had very different effects on arsenic and phosphorus uptake.

  19. The co-occurrence of ectomycorrhizal, arbuscular mycorrhizal, and dark septate fungi in seedlings of four members of the Pinaceae.

    Science.gov (United States)

    Wagg, Cameron; Pautler, Michael; Massicotte, Hugues B; Peterson, R Larry

    2008-02-01

    Although roots of species in the Pinaceae are usually colonized by ectomycorrhizal (EM) fungi, there are increasing reports of the presence of arbuscular mycorrhizal (AM) and dark septate endophytic (DSE) fungi in these species. The objective of this study was to determine the colonization patterns in seedlings of three Pinus (pine) species (Pinus banksiana, Pinus strobus, Pinus contorta) and Picea glauca x Picea engelmannii (hybrid spruce) grown in soil collected from a disturbed forest site. Seedlings of all three pine species and hybrid spruce became colonized by EM, AM, and DSE fungi. The dominant EM morphotype belonged to the E-strain category; limited colonization by a Tuber sp. was found on roots of Pinus strobus and an unknown morphotype (cf. Suillus-Rhizopogon group) with thick, cottony white mycelium was present on short roots of all species. The three fungal categories tended to occupy different niches in a single root system. No correlation was found between the percent root colonized by EM and percent colonization by either AM or DSE, although there was a positive correlation between percent root length colonized by AM and DSE. Hyphae and vesicles were the only AM intracellular structures found in roots of all species; arbuscules were not observed in any roots. PMID:18157555

  20. Glomus africanum and G. iranicum, two new species of arbuscular mycorrhizal fungi (Glomeromycota).

    Science.gov (United States)

    Błaszkowski, Janusz; Kovács, Gábor M; Balázs, Tímea K; Orlowska, Elzbieta; Sadravi, Mehdi; Wubet, Tesfaye; Buscot, François

    2010-01-01

    Two new arbuscular mycorrhizal fungal species (Glomeromycota) of genus Glomus, G. africanum and G. iranicum, are described and illustrated. Both species formed spores in loose clusters and singly in soil and G. iranicum sometimes inside roots. G. africanum spores are pale yellow to brownish yellow, globose to subglobose, (60-)87(-125) μm diam, sometimes ovoid to irregular, 80-110 x 90-140 μm. The spore wall consists of a semipermanent, hyaline, outer layer and a laminate, smooth, pale yellow to brownish yellow, inner layer, which always is markedly thinner than the outer layer. G. iranicum spores are hyaline to pastel yellow, globose to subglobose, (13-)40(-56) μm diam, rarely egg-shaped, prolate to irregular, 39-54 x 48-65 μm. The spore wall consists of three smooth layers: one mucilaginous, short-lived, hyaline, outermost; one permanent, semirigid, hyaline, middle; and one laminate, hyaline to pastel yellow, innermost. Only the outermost spore wall layer of G. iranicum stains red in Melzer's reagent. In the field G. africanum was associated with roots of five plant species and an unrecognized shrub colonizing maritime sand dunes of two countries in Europe and two in Africa, and G. iranicum was associated with Triticum aestivum cultivated in southwestern Iran. In one-species cultures with Plantago lanceolata as the host plant G. africanum and G. iranicum formed arbuscular mycorrhizae. Phylogenetic analyses of partial SSU sequences of nrDNA placed the two new species in Glomus group A. Both species were distinctly separated from sequences of described Glomus species.

  1. Status and diversity of arbuscular mycorrhizal fungi and its role in natural regeneration on limestone mined spoils

    OpenAIRE

    ANUJ KUMAR SINGH; JAMALUDDIN

    2011-01-01

    Singh AK, Jamaluddin (2011) Status and diversity of arbuscular mycorrhizal fungi and its role in natural regeneration on limestone mined spoils. Biodiversitas 12: 107-111. Limestone mined spoils are devoid of adequate population of beneficial microbial flora. Arbuscular mycorrhizal fungi (AMF) are very important constituent of plant- soil-microbe system. In mined spoils the population of AMF is greatly reduced and hence the spoils become very inhospitable for establishment of vegetation. In t...

  2. 荒漠植物根际AM真菌的空间分布和定殖%SPATIAL DISTRIBUTION AND COLONIZATION OF ARBUSCULAR MYCORRHIZAL FUNGI IN THE RHIZOSPHERE OF DESERT SHRUBS

    Institute of Scientific and Technical Information of China (English)

    贺学礼; StanislovMOURATOV; 等

    2002-01-01

    -20, 20-30, 30-40 and 40-50 cm in the rhizosphere of each plant. Before processing, soil samples were sieved (2 mm mesh size) and root segments were collected from each sample.Subsamples from each replicate were used for soil moisture, organic matter and total soluble N determination. The total AM fungal spore number was determined by wet sieving (45-500 μm) and sucrose density centrifugation,and counting under a stereoscopic microscope at ×40. Root samples were cut into 1 cm long pieces, then cleared with 10% (w/v) KOH and stained with 0.05% (v/v) trypan blue in lactophenol. Colonization assessment was conducted on each sample by the glass slide method on which 50 randomly selected 1 cm root segment units were determined microscopically. The results showed that different plant species significantly affected AM fungal colonization and spore density. Higher spore density tended to be correlated with higher AM fungal colonization in the rhizosphere of A. herba-alba and A. halimus, and vice versa for Z. dumosum and H. scoparia.At the tested soil depths, the highest AM fungal colonization occurring at the 20-30 cm section did not coincide with higher spore density existing at the 10-20 cm section. Sampling depth of soil had a significant effect on spore density and the percent colonization of total, vesicle and arbuscule. Spore density had a positive correlation with vesicular colonization and a negative correlation with arbuscular colonization. Soil total soluble N exhibited a negative effect on spore density. Soil moisture and organic matter content did not exhibit a significant correlation with AM fungal colonization or spore density. The distribution and colonization of AM fungi, especially spore density, vesicular and arbuscular colonization are a useful indicator for monitoring the change of desert soil ecosystem and evaluating the ability of forming mycorrhizae of different plant species.

  3. Colonization features of arbuscular mycorrhizal fungi and dark septate endophytic fungi in roots of cucumber plants in protected cultivation%设施栽培黄瓜根内AMF与DSE结构发育特征

    Institute of Scientific and Technical Information of China (English)

    田蜜; 李敏; 刘润进

    2015-01-01

    本研究旨在观察和测定设施栽培黄瓜根系丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)与暗隔内生真菌(dark septate endophytic fungi,DSE)形态结构,明确其发育特征,为进一步探索AMF与DSE相互作用奠定基础.自山东莱阳、寿光和莱西等设施蔬菜主产区选择黄瓜Cucumis sativus样地,从不同连作年限、黄瓜生育期和土层深度分别采集黄瓜根系和根区土壤;观察根内AMF与DSE形态特征、测定AMF和DSE侵染数量、分析AMF或DSE侵染发育数量与黄瓜根结线虫Meloidogyne incognita病害的相关性.从黄瓜根系中可观察到典型的AMF泡囊、疆南星型(Arum,A)与重楼型(Paris,P)丛枝结构、DSE菌丝和微菌核.以黄瓜结果中期根系AMF和DSE侵染率最高,分别为57%和28%,苗期最低,分别为18%和8%;初花期的丛枝为P型,苗期和结果中期则为A型+P型.连作<7年和7-10年的黄瓜根内丛枝为A型+P型,AMF和DSE的侵染率均分别显著高于连作>10年的侵染率,连作>10年的丛枝为A型.黄瓜根系以0-15cm土层中AMF侵染率最高(29%),丛枝为P型;以>30cm的侵染率最低(12%),丛枝为A型;15-30cm土层的为A型+P型.AMF P型着生率、P/A比率和DSE侵染率分别与根结线虫病的为害程度具有相关性.研究结果还表明黄瓜根系AMF侵染率与DSE侵染率呈显著正相关关系.

  4. Arbuscular mycorrhizal fungi associated with the clonal plants in Mu Us sandland of China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Clonal plants in Mu Us sandland change the sandy enviroment. The clonal plant is a kind of resource in restoration of the Mu Us sandy landscape. Soil samples at depth of 50 cm in the rhizosphere of the clonal plants were collected in 4 replicates at each location and divided into sections corresponding to 0-10, 10-20, 20-30, 30-40 and 40-50 cm depths in two representative sites from north to south in Mu Us sandland, northwestern China, in July 2005. Clonal plants included Psammochloa villosa and Hedysarum laeve.The colonization and ecological distribution of arbuscular mycorrhizal (AM) fungi were investigated in the rhizosphere of clonal plants in Mu Us sandland. The results showed that the clonal plants established well symbiosis with AM fungi; AM fungal species and spatial distribution were significantly related with the host plants and soil factors. Of 16 AM fungal taxa in three genera isolated and identified, Glomus multicaule was only observed in the rhizosphere of Psammochloa villosa ; Glomus aggregatum, Glomus h ydembadensis, Glomus constrictum and Acaulospora rehmii only appeared in the rhizosphere of Hedysarum leave. The depth of soil layers observably affected the spore density and the frequency of colonization ( % F). The maximal % F and spore density occurred in the 10-20 cm layer at the site of Ordos Sandy Land Ecological Station, but which occurred in the 0-10 cm layer in Shanxi Yulin Rare Sandy-plants Conversation Field.AM fungal status and colonization might be used to monitor desertification and soil degradation.

  5. Propagules of arbuscular mycorrhizal fungi in a secondary dry forest of Oaxaca, Mexico.

    Science.gov (United States)

    Guadarrama, Patricia; Castillo-Argüero, Silvia; Ramos-Zapata, José A; Camargo-Ricalde, Sara L; Alvarez-Sánchez, Javier

    2008-03-01

    Plant cover loss due to changes in land use promotes a decrease in spore diversity of arbuscular mycorrhizal fungi (AMF), viable mycelium and, therefore, in AMF colonization, this has an influence in community diversity and, as a consequence, in its recovery. To evaluate different AMF propagules, nine plots in a tropical dry forest with secondary vegetation were selected: 0, 1, 7, 10, 14, 18, 22, 25, and 27 years after abandonment in Nizanda, Oaxaca, Mexico. The secondary vegetation with different stages of development is a consequence of slash and burn agriculture, and posterior abandonment. Soil samples (six per plot) were collected and percentage of AMF field colonization, extrarradical mycelium, viable spore density, infectivity and most probable number (MPN) ofAMF propagules were quantified through a bioassay. Means for field colonization ranged between 40% and 70%, mean of total mycelium length was 15.7 +/- 1.88 mg(-1) dry soil, with significant differences between plots; however, more than 40% of extracted mycelium was not viable, between 60 and 456 spores in 100 g of dry soil were recorded, but more than 64% showed some kind of damage. Infectivity values fluctuated between 20% and 50%, while MPN showed a mean value of 85.42 +/- 44.17 propagules (100 g dry soil). We conclude that secondary communities generated by elimination of vegetation with agricultural purposes in a dry forest in Nizanda do not show elimination of propagules, probably as a consequence of the low input agriculture practices in this area, which may encourage natural regeneration. PMID:18624242

  6. Root Respiration and Growth in Plantago major as Affected by Vesicular-Arbuscular Mycorrhizal Infection.

    Science.gov (United States)

    Baas, R; van der Werf, A; Lambers, H

    1989-09-01

    Effects of vesicular-arbuscular mycorrhizal (VAM) infection and P on root respiration and dry matter allocation were studied in Plantago major L. ssp. pleiosperma (Pilger). By applying P, the relative growth rate of non-VAM controls and plants colonized by Glomus fasciculatum (Thaxt. sensu Gerdemann) Gerdemann and Trappe was increased to a similar extent (55-67%). However, leaf area ratio was increased more and net assimilation rate per unit leaf area was increased less by VAM infection than by P addition. The lower net assimilation rate could be related to a 20 to 30% higher root respiration rate per unit leaf area of VAM plants. Root respiration per unit dry matter and specific net uptake rates of N and P were increased more by VAM infection than by P addition. Neither the contribution of the alternative respiratory path nor the relative growth rate could account for the differences in root respiration rate between VAM and non-VAM plants. It was estimated that increased fungal respiration (87%) and ion uptake rate (13%) contributed to the higher respiratory activity of VAM roots of P. major.

  7. Root Respiration and Growth in Plantago major as Affected by Vesicular-Arbuscular Mycorrhizal Infection.

    Science.gov (United States)

    Baas, R; van der Werf, A; Lambers, H

    1989-09-01

    Effects of vesicular-arbuscular mycorrhizal (VAM) infection and P on root respiration and dry matter allocation were studied in Plantago major L. ssp. pleiosperma (Pilger). By applying P, the relative growth rate of non-VAM controls and plants colonized by Glomus fasciculatum (Thaxt. sensu Gerdemann) Gerdemann and Trappe was increased to a similar extent (55-67%). However, leaf area ratio was increased more and net assimilation rate per unit leaf area was increased less by VAM infection than by P addition. The lower net assimilation rate could be related to a 20 to 30% higher root respiration rate per unit leaf area of VAM plants. Root respiration per unit dry matter and specific net uptake rates of N and P were increased more by VAM infection than by P addition. Neither the contribution of the alternative respiratory path nor the relative growth rate could account for the differences in root respiration rate between VAM and non-VAM plants. It was estimated that increased fungal respiration (87%) and ion uptake rate (13%) contributed to the higher respiratory activity of VAM roots of P. major. PMID:16667001

  8. Arbuscular mycorrhizal fungi protect a native plant from allelopathic effects of an invader.

    Science.gov (United States)

    Barto, Kathryn; Friese, Carl; Cipollini, Don

    2010-04-01

    The allelopathic potential of the Eurasian invasive plant Alliaria petiolata has been well documented, with the bulk of the effects believed to be mediated by arbuscular mycorrhizal fungi (AMF). We exposed the herbaceous annual Impatiens pallida, which is native to North America, to fractionated A. petiolata extracts at four developmental stages (germination, presymbiosis growth, symbiosis formation, and symbiosis growth) by using exposure levels expected to be similar to field levels. Surprisingly, we found strong direct effects on I. pallida germination and growth, but no indirect effects on I. pallida growth mediated by AMF. We also observed strong synergistic effects with a complete A. petiolata extract that inhibited I. pallida germination and presymbiosis root growth more than either a glucosinolate or flavonoid enriched fraction alone. In fact, the flavonoid enriched fraction tended to stimulate germination and presymbiosis root growth. In contrast to these strong direct effects, I. pallida plant growth during both the symbiosis formation and symbiosis growth phases was unaffected by A. petiolata extracts. We also found no inhibition of AMF colonization of roots or soils by A. petiolata extracts. We show that AMF can actually ameliorate allelopathic effects of an invasive plant, and suggest that previously observed allelopathic effects of A. petiolata may be due to direct inhibition of plant and fungal growth before symbiosis formation. PMID:20229215

  9. Mycoparasitism of arbuscular mycorrhizal fungi: a pathway for the entry of saprotrophic fungi into roots.

    Science.gov (United States)

    De Jaeger, Nathalie; Declerck, Stéphane; de la Providencia, Ivan E

    2010-08-01

    Within the rhizosphere, arbuscular mycorrhizal (AM) fungi interact with a cohort of microorganisms, among which is the biological control agent, Trichoderma spp. This fungus parasitizes a wide range of phytopathogenic fungi, a phenomenon also reported in the extraradical mycelium (ERM) of AM fungi. Here, we question whether the mycoparasitism of the ERM could be extended to the intraradical mycelium (IRM), thus representing a pathway for the entry of Trichoderma harzianum within the root. Microcosm experiments allowing interactions between Glomus sp. MUCL 41833 placed in a clade that contains the recently described species Glomus irregulare and T. harzianum were set up under in vitro autotrophic culture conditions using potato as a host. A microscope camera-imaging system, coupled with succinate dehydrogenase staining, was used to assess the mycoparasitism in the ERM and IRM. Trichoderma harzianum colonized the ERM of the AM fungus and spread into the IRM, before exiting into the root cells. Intrahyphal growth of T. harzianum caused protoplasm degradation, decreasing the ERM and IRM viability. ERM of the AM fungus represented a pathway for the entry of T. harzianum into the roots of potato. It further sets off the debate on the susceptibility of the AM fungi of being infected by microorganisms from the rhizosphere. PMID:20533946

  10. Inoculant of arbuscular mycorrhizal fungi (Rhizophagus clarus increase yield of soybean and cotton under field conditions

    Directory of Open Access Journals (Sweden)

    Martha Viviana Torres Cely

    2016-05-01

    Full Text Available Nutrient availability is an important factor in crop production, and regular addition of chemical fertilizers is the most common practice to improve yield in agrosystems for intensive crop production. The use of some groups of microorganisms that have specific activity providing nutrients to plants is a good alternative, and arbuscular mycorrhizal fungi (AMF enhance plant nutrition by providing especially phosphorus (P, improving plant growth and increasing crop production. Unfortunately, the use of AMF as an inoculant on a large scale is not yet widely used, because of several limitations in obtaining a large amount of inoculum due to several factors, such as low growth, the few species domesticated under in vitro conditions, and high competition with native AMF. The objective of this work was to test the infectivity of a Rhizophagus clarus inoculum and its effectiveness as an alternative for P supply in soybean (Glycine max L. and cotton (Gossypium hirsutum L.. The experiments were carried out in plots and the treatments were: Fertilizer; AMF, AMF + Fertilizer and AMF + ½ Fertilizer; non-inoculated and non-fertilized plants were considered the control. The parameters evaluated were AMF root colonization and effect of inoculation on plant growth and yield under a field conditions. The results showed that AMF inoculation increased the effect of fertilizer application in soybean, and that in cotton R. clarus was more effective than chemical fertilizer

  11. Initial development and chemical components of sugarcane under water stress associated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Carmem C. M. de Sousa

    2015-06-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the effects of water stress levels in the soil and a mix (or: a mixed inoculum of four species: Claroideoglomus etunicatum, Gigasporas rosea, Acaulospora longula, Fuscutata heterogama of arbuscular mycorrhizal fungi (AMF on initial vegetative growth, fresh and dry biomass production, root colonization, phosphorus, proteins, enzymes and amino acid of the sugarcane variety RB 857515 under greenhouse conditions. The experiment was set in a randomized block design in a 2 x 2 factorial scheme with four treatments (T1 - 50% PC - pot capacity, with AMF; T2 - 100% PC with AMF; T3 - 50% PC without AMF; T4 - 100% PC without AMF with 16 replicates. The water stress level of 50% PC decreased stem diameter and shoot and root fresh weight of sugarcane plants, as well as AMF in the soil and in plant roots. However, AMF and the water stress level of 50% PC, separately or combined, did not affect plant height, number of leaves, dry matter and contents of phosphorus, total soluble proteins, catalase, ascorbate peroxidase, polyphenoloxidase, peroxidase and proline of the sugarcane variety RB857515.

  12. The occurrence of arbuscular mycorrhizal fungi of the phylum Glomeromycota in Israeli soils

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2011-04-01

    Full Text Available In December 1997 and June-July 2000, 49 and 113 rhizosphere soil and root mixtures were collected, respectively, to determine the occurrence of arbuscular mycorrhizal fungi (AMF of the phylum Glomeromycota in different sites of Israel. Except for five samples taken from under cultivated plants, all the others came from under Ammophila arenaria and Oenothera drummondii colonizing sand dunes adjacent to the Mediterranean Sea. After a continuous cultivation of the mixtures in pot trap cultures with Plantago lanceolata as the plant host up to 2006 and their examination at least twice a year, spores of AMF were found in 41 and 103 cultures with the 1997 and 2000 soil and root mixtures, respectively. The spores represented 30 species and 8 undescribed morphotypes in 7 genera of the Glomeromycota. The AMF most frequently found in Israeli soils were Glomus aurantium and G. constrictum, followed by G. coronatum, G. gibbosum, an undescribed Glomus 178, and Scutellospora dipurpurescens. Up to 2001, 21 species of AMF were known to occur in Israel, and this paper increases this number to 33, of which 11 are new fungi for this country. Moreover, four species, G. aurantium, G. drummondii, G. walkeri and G. xanthium, were recently described as new for science based on spores isolated from Israeli soils. Additionally, the general distribution in the world of the formally described species found in Israel was presented.

  13. Clonality and recombination in the life history of an asexual arbuscular mycorrhizal fungus.

    Science.gov (United States)

    den Bakker, Henk C; Vankuren, Nicholas W; Morton, Joseph B; Pawlowska, Teresa E

    2010-11-01

    Arbuscular mycorrhizal (AM) fungi in the phylum Glomeromycota colonize roots of the majority of land plants and assist them in the uptake of mineral nutrients in exchange for plant-assimilated carbon. In the absence of sexual reproductive structures and with asexual spore morphology conserved since the Ordovician, Glomeromycota may be one of the oldest eukaryotic lineages that rely predominantly on asexual reproduction for gene transmission. Clonal population structure detected in the majority of AM fungi examined to date supports this hypothesis. However, evidence of recombination found in few local populations suggests that genetic exchanges may be more common in these organisms than is currently recognized. To explore the significance of clonal expansion versus genetic recombination in the life history of modern Glomeromycota, we examined the global population of a cosmopolitan fungus Glomus etunicatum and made inferences about the population structure and the occurrence of recombination in the history of this species. We sampled eight loci from 84 isolates. We found that although the global population of G. etunicatum showed a pattern of significant differentiation, several haplotypes had a broad geographic distribution spanning multiple continents. Molecular variation among the sampled isolates indicated an overwhelmingly clonal population structure and suggested that clonal expansion plays an important role in the ecological success of modern Glomeromycota. In contrast, a pattern of homoplasy consistent with a history of recombination suggested that gene exchanges are not completely absent from the life history of these organisms, although they are likely to be very rare.

  14. Mitochondrial large ribosomal subunit sequences are homogeneous within isolates of Glomus (arbuscular mycorrhizal fungi, Glomeromycota).

    Science.gov (United States)

    Raab, Philipp A; Brennwald, Annemarie; Redecker, Dirk

    2005-12-01

    Partial sequences of the mtLSU rDNA were obtained from the arbuscular mycorrhizal (AM) fungi Glomus proliferum (isolate DAOM 226389) and G. intraradices (isolates JJ291 and BEG75). The exon sequences of the two species showed regions of strong divergence. There was no evidence of intra-isolate sequence heterogeneity as it is found in variable regions of nuclear ribosomal genes of Glomeromycota. In G. intraradices JJ291, two introns were found in the partial LSU sequence. One of the introns contained an ORF for a putative site-specific homing endonuclease of the LAGLIDADG family. In G. intraradices BEG75, one of the introns was missing and the other had a DNA sequence distinct from JJ291. G. proliferum had no introns in the region sequenced. A PCR primer was designed to amplify the fragment of the mtLSU of a different, distinguishable G. intraradices genotype from colonized roots of a field sample. These mitochondrial gene sequences are the first reported from the phylum Glomeromycota. Our findings indicate that the intra-individual sequence heterogeneity of the Glomeromycota may be a peculiar feature of the nuclear genes. Therefore, mtLSU and its introns have the potential to be highly sensitive genetic markers for these fungi in the future.

  15. The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Chavez, M.C.; Carrillo-Gonzalez, R.; Wright, S.F.; Nichols, K.A

    2004-08-01

    Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 {mu}M of Cu. Although no differences between isolates were detected, mean values for the 20 {mu}M Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. - Glomalin may be useful in remediation of toxic elements in soils.

  16. Arbuscular mycorrhizal fungi regulate soil respiration and its response to precipitation change in a semiarid steppe

    Science.gov (United States)

    Zhang, Bingwei; Li, Shan; Chen, Shiping; Ren, Tingting; Yang, Zhiqiang; Zhao, Hanlin; Liang, Yu; Han, Xingguo

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are critical links in plant-soil continuum and play a critical role in soil carbon cycles. Soil respiration, one of the largest carbon fluxes in global carbon cycle, is sensitive to precipitation change in semiarid ecosystems. In this study, a field experiment with fungicide application and water addition was conducted during 2010-2013 in a semiarid steppe in Inner Mongolia, China, and soil respiration was continuously measured to investigate the influences of AMF on soil respiration under different precipitation regimes. Results showed that soil respiration was promoted by water addition treatment especially during drought seasons, which induced a nonlinear response of soil respiration to precipitation change. Fungicide application suppressed AMF root colonization without impacts on soil microbes. AMF suppression treatment accelerated soil respiration with 2.7, 28.5 and 37.6 g C m-2 across three seasons, which were mainly caused by the enhanced heterotrophic component. A steeper response of soil respiration rate to precipitation was found under fungicide application treatments, suggesting a greater dampening effect of AMF on soil carbon release as water availability increased. Our study highlighted the importance of AMF on soil carbon stabilization and sequestration in semiarid steppe ecosystems especially during wet seasons.

  17. 广州地区7种菊科入侵植物丛枝菌根侵染和根际土壤孢子密度的生境差异性分析%Habitat Difference Analysis of Arbuscular Mycorrhizal Colonization and Spore Density for Seven Compositae Invasive Species in Guangzhou

    Institute of Scientific and Technical Information of China (English)

    胡文武; 辛国荣; 郭健桦; 彭雪

    2015-01-01

    为了解广州地区7种菊科(Compositae)入侵植物与丛枝菌根真菌(Arbuscular mycorrhizal fungi, AMF)的互作共生关系,调查了这7种菊科入侵植物在4种生境中的AMF侵染和根际土壤孢子密度,并分析土壤因子对AMF的影响。结果表明,7种入侵植物根内均受到AMF侵染,根际土壤中均检测到AMF孢子;AMF侵染在宿主间差异显著,生境间的差异不显著;孢子密度在生境和宿主间的差异均显著,人工绿地、农田果园的AMF孢子密度均显著高于森林周边和滨海地带。相关性分析表明,农田果园生境的根际土壤孢子密度与土壤有机质含量呈显著负相关关系;森林周边生境的AMF总侵染率与土壤全氮呈极显著正相关关系;人工绿地的AMF总侵染率与土壤速效氮含量呈显著负相关关系;滨海地带的AMF总侵染率与土壤有效磷含量呈显著负相关关系。这些对理解菊科植物入侵机理具有非常重要的作用。%In order to understand the symbiosis of arbuscular mycorrhizal fungi (AMF) with Compositae invasive plants in Guangzhou, the AMF colonization rate and spore density of 7 Compositae invasive plant species in four habitats were studied, and the effect of soil factors on AMF was also analyzed. The results showed that all the investigated plants were colonized by AMF, AMF spores were detected from all soil samples. AMF colonization rate showed significant difference among hosts, but not among habitats. AMF spore density was significantly different both among hosts and habitats, among which, spore density was signiifcantly higher in artiifcial green land, farmland and orchard than that in forest surround and coastal area. Correlation analysis showed that spore density was negatively correlated with soil organic matter content in farmland and orchard, AMF colonization rate was positively correlated with total N content in forest surround, AMF colonization rate was negatively

  18. Arbuscular mycorrhizal symbiosis can mitigate the negative effects of night warming on physiological traits of Medicago truncatula L.

    Science.gov (United States)

    Hu, Yajun; Wu, Songlin; Sun, Yuqing; Li, Tao; Zhang, Xin; Chen, Caiyan; Lin, Ge; Chen, Baodong

    2015-02-01

    Elevated night temperature, one of the main climate warming scenarios, can have profound effects on plant growth and metabolism. However, little attention has been paid to the potential role of mycorrhizal associations in plant responses to night warming, although it is well known that symbiotic fungi can protect host plants against various environmental stresses. In the present study, physiological traits of Medicago truncatula L. in association with the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were investigated under simulated night warming. A constant increase in night temperature of 1.53 °C significantly reduced plant shoot and root biomass, flower and seed number, leaf sugar concentration, and shoot Zn and root P concentrations. However, the AM association essentially mitigated these negative effects of night warming by improving plant growth, especially through increased root biomass, root to shoot ratio, and shoot Zn and root P concentrations. A significant interaction was observed between R. irregularis inoculation and night warming in influencing both root sucrose concentration and expression of sucrose synthase (SusS) genes, suggesting that AM symbiosis and increased night temperature jointly regulated plant sugar metabolism. Night warming stimulated AM fungal colonization but did not influence arbuscule abundance, symbiosis-related plant or fungal gene expression, or growth of extraradical mycelium, indicating little effect of night warming on the development or functioning of AM symbiosis. These findings highlight the importance of mycorrhizal symbiosis in assisting plant resilience to climate warming. PMID:25033924

  19. Possible evidence for contribution of arbuscular mycorrhizal fungi (AMF) in phytoremediation of iron-cyanide (Fe-CN) complexes.

    Science.gov (United States)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2016-08-01

    Arbuscular mycorrhizal fungi (AMF) are integral functioning parts of plant root systems and are widely recognized for enhancing contaminants uptake and metabolism on severely disturbed sites. However, the patterns of their influence on the phytoremediation of iron-cyanide (Fe-CN) complexes are unknown. Fe-CN complexes are of great common interest, as iron is one of the most abundant element in soil and water. Effect of ryegrass (Lolium perenne L.) roots inoculation, using mycorrhizal fungi (Rhizophagus irregularis and a mixture of R. irregularis, Funneliformis mosseae, Rhizophagus aggregatus, and Claroideoglomus etunicatum), on iron-cyanide sorption was studied. Results indicated significantly higher colonization of R. irregularis than the mixture of AMF species on ryegrass roots. Series of batch experiments using potassium hexacyanoferrate (II) solutions, in varying concentrations revealed significantly higher reduction of total CN and free CN content in the mycorrhizal roots, indicating greater cyanide decrease in the treatment inoculated with R. irregularis. Our study is a first indication of the possible positive contribution of AM fungi on the phytoremediation of iron-cyanide complexes. PMID:27256319

  20. Diversity of arbuscular mycorrhizal fungi associated with desert ephemerals growing under and beyond the canopies of Tamarisk shrubs

    Institute of Scientific and Technical Information of China (English)

    SHI Zhaoyong; ZHANG Liyun; FENG Gu; Christie Peter; TIAN Changyan; LI Xiaolin

    2006-01-01

    The arbuscular mycorrhizal (AM) fungal status of the four most common ephemeral plant species, Chorispora tenella (Pall.) DC., Ceratocephalus testiculatus (Crantz) Bess., Eremopyrum orientale (L.) Jaub et. Spash and Veronica campylopoda Boiss growing in an area dominated by Tamarisk shrubs (Tamarix spp.) was investigated.Samples of the four ephemerals and their rhizosphere soils were collected from underneath and beyond the canopies of the Tamarisk shrubs.Plant mycorrhizal status and soil AM fungal spore densities and community structures were analyzed and compared under and beyond the shrub canopies.The mycorrhizal colonization rates of the ephemerals and spore densities in their corresponding rhizosphere soils were significantly lower under the shrub canopies than beyond. The number of AM fungal species under the shrubs (12) was also lower than beyond the canopies (19). When soil properties in the rhizospheres of the four ephemerals were examined, available N and P and total P, organic matter content, total salt content and electrical conductivity (EC) were all higher under the canopies than beyond. In contrast, soil available K and pH showed no such trend. A total of 21 AM fungal species were isolated from rhizosphere soils of the four ephemerals. Five belonged to Acaulospora, one to Archaeospora, thirteen to Glomus and two to Paraglomus. We conclude that the canopies of Tamarix spp. exerted some influence on the AM status of the ephemerals and on the AM fungal communities and some of the properties of their rhizosphere soils.

  1. Nursery inoculation with the arbuscular mycorrhizal fungus Glomus viscosum and its effect on the growth and physiology of hybrid artichoke seedlings

    Directory of Open Access Journals (Sweden)

    Angela Campanelli

    2011-07-01

    Full Text Available Most nurseries operating in Italy adopt high technologies and produce transplants that well suit and satisfy the grower’s need to produce high value crops. Mycorrhizas are discussed as a tool for improving and developing plant production in the nursery. Much research has been carried out on mycorrhizal symbiosis and we now know more about the symbiontic relationship between fungi and host plants. Plants receive numerous benefits from this symbiosis which are more macroscopic the earlier in the ontogenetic cycle this symbiosis is established. Therefore, it appears that the most effective period in which the inoculum should be made corresponds to the in-nursery growing stage. The earlier the plant is inoculated, the more evident the effect will be. In this study, several aspects related to the physiological foundations of arbuscular mycorrhiza in artichoke plants are presented. The main goal was to study the effects of mycorrhiza on the growth and physiological parameters of three hybrids of artichokes growing in the nursery. The experimental 3¥2 design included two treatments (with or without arbuscular mycorrhizal fungi and three hybrids of artichokes marketed by Nunhems (Opal F1, Madrigal F1, Concerto F1. Mycorrhizal plants have greater shoot length, leaf area, shoot and root fresh and dry mass, and root density. This also corresponded with increased photosynthetic rates and stomatal conductance of mycorrhizal plants. Mycorrhizal colonization improves relative water content and increases proline concentration in vegetal tissue. Inoculation produced the most beneficial effect on hybrid Madrigal F1 and on hybrid Opal F1; the best mycorrhizal affinity was enhanced when compared to hybrid Concerto F1. The results showed that mycorrhizal symbiosis stimulated the growth of inoculated seedlings providing a qualitatively good propagation material.

  2. Reduction of bacterial growth by a vesicular-arbuscular mycorrhizal fungus in the rhizosphere of cucumber (Cucumis sativus L.)

    DEFF Research Database (Denmark)

    Christensen, H.; Jakobsen, I.

    1993-01-01

    Cucumber was grown in a partially sterilized sand-soil mixture with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum or left uninoculated. Fresh soil extract was places in polyvinyl chloride tubes without propagules of mycorrhizal fungi. Root tips and root segments...

  3. Septoglomus fuscum and S. furcatum, two new species of arbuscular mycorrhizal fungi (Glomeromycota)

    DEFF Research Database (Denmark)

    Blaszkowski, Janusz; Chwat, Gerad; Kovacs, Gábor M;

    2013-01-01

    Two new arbuscular mycorrhizal fungal species, (Glomeromycota) Septoglomus fuscum and S. furcatum, are described and illustrated. Spores of S. fuscum usually occur in loose hypogeous clusters, rarely singly in soil or inside roots, and S. furcatum forms only single spores in soil. Spores of S. fu...... as host plant, S. fuscum and S. furcatum formed arbuscular mycorrhizae. Phylogenetic analyses of the SSU, ITS and LSU nrDNA sequences placed the two new species in genus Septoglomus and both new taxa were separated from described Septoglomus species....

  4. Arbuscular Mycorrhizal Fungi May Mitigate the Influence of a Joint Rise of Temperature and Atmospheric CO2 on Soil Respiration in Grasslands

    Directory of Open Access Journals (Sweden)

    S. Vicca

    2009-01-01

    Full Text Available We investigated the effects of mycorrhizal colonization and future climate on roots and soil respiration (Rsoil in model grassland ecosystems. We exposed artificial grassland communities on pasteurized soil (no living arbuscular mycorrhizal fungi (AMF present and on pasteurized soil subsequently inoculated with AMF to ambient conditions and to a combination of elevated CO2 and temperature (future climate scenario. After one growing season, the inoculated soil revealed a positive climate effect on AMF root colonization and this elicited a significant AMF x climate scenario interaction on root biomass. Whereas the future climate scenario tended to increase root biomass in the noninoculated soil, the inoculated soil revealed a 30% reduction of root biomass under warming at elevated CO2 (albeit not significant. This resulted in a diminished response of Rsoil to simulated climatic change, suggesting that AMF may contribute to an attenuated stimulation of Rsoil in a warmer, high CO2 world.

  5. Effect of arbuscular mycorrhizal fungi and phosphate fertilization on initial growth of six arboreal species of cerrado

    Directory of Open Access Journals (Sweden)

    Kenia Alves Pereira Lacerda

    2011-09-01

    Full Text Available This study evaluated the benefit of inoculation with arbuscular mycorrhizal fungi, Glomus clarum, for the initial growth of some native arboreal species of the Cerrado biome, namely gabiroba (Campomanesia cambessedeana, baru (Dipterix alata, jatobá (Hymenaea courbaril, ingá (Inga laurina, caroba (Jacaranda cuspidifolia and chichá (Sterculia striata, in unsterilized soil with low (0.02 mg L‑1 and high (0.2 mg L‑1 concentrations of P in the soil solution. Experiments were conducted in a greenhouse, using 1.5 kg vases, for up to 120 days. The experimental design for each arboreal species was completely randomized, with ten replicates in a 2x2 factorial design (inoculated and noninoculated seedlings, and two levels of phosphorus (P in the soil solution. Arboreal plants of the Cerrado biome showed increased mycorrhizal colonization from inoculation with Glomus clarum, except chichá, as this species showed a high indigenous colonization, not differing from the colonization promoted by inoculated fungi. Inoculation promoted increased growth in baru, gabiroba, ingá, caroba and chichá, increasing shoot dry matter (MSPA and root dry matter (MSR. In caroba, this effect was synergistic with application of P to the soil. Baru and jatobá showed increased dry matter with application of P to the soil only. The mycotrophy (mycorrhizal dependence of species and their response to inoculation and to phosphorus are discussed. In order to produce quality seedlings of caroba, gabiroba, chichá and ingá, combining inoculation with Glomus clarum and phosphate fertilization of the soil is recommended, while for jatobá and baru only the application of P to the soil is recommended.

  6. Improvement of the soil nitrogen content and maize growth by earthworms and arbuscular mycorrhizal fungi in soils polluted by oxytetracycline.

    Science.gov (United States)

    Cao, Jia; Wang, Chong; Ji, Dingge

    2016-11-15

    Interactions between earthworms (Eisenia fetida) and arbuscular mycorrhizal fungi (Rhizophagus intraradices, AM fungi) have been suggested to improve the maize nitrogen (N) content and biomass and were studied in soils polluted by oxytetracycline (OTC). Maize was planted and amended with AMF and/or earthworms (E) in the soil with low (1mgkg(-1) soil DM) or high (100mgkg(-1) soil DM) amounts of OTC pollution in comparison to soil without OTC. The root colonization, shoot and root biomass, shoot and root N contents, soil nitrogen forms, ammonia-oxidizing bacteria (AOB) and archaea (AOA) were measured at harvest. The results indicated that OTC decreased maize shoot and root biomass (pfungi on the urease activity in soil polluted by OTC (pfungi could increase the maize biomass and N content (pfungi and earthworms interactively increased maize shoot and root biomass (pfungi could be used as an efficient method to relieve the OTC stress in agro-ecosystems. PMID:27496075

  7. Inoculant of Arbuscular Mycorrhizal Fungi (Rhizophagus clarus) Increase Yield of Soybean and Cotton under Field Conditions.

    Science.gov (United States)

    Cely, Martha V T; de Oliveira, Admilton G; de Freitas, Vanessa F; de Luca, Marcelo B; Barazetti, André R; Dos Santos, Igor M O; Gionco, Barbara; Garcia, Guilherme V; Prete, Cássio E C; Andrade, Galdino

    2016-01-01

    Nutrient availability is an important factor in crop production, and regular addition of chemical fertilizers is the most common practice to improve yield in agrosystems for intensive crop production. The use of some groups of microorganisms that have specific activity providing nutrients to plants is a good alternative, and arbuscular mycorrhizal fungi (AMF) enhance plant nutrition by providing especially phosphorus, improving plant growth and increasing crop production. Unfortunately, the use of AMF as an inoculant on a large scale is not yet widely used, because of several limitations in obtaining a large amount of inoculum due to several factors, such as low growth, the few species of AMF domesticated under in vitro conditions, and high competition with native AMF. The objective of this work was to test the infectivity of a Rhizophagus clarus inoculum and its effectiveness as an alternative for nutrient supply in soybean (Glycine max L.) and cotton (Gossypium hirsutum L.) when compared with conventional chemical fertilization under field conditions. The experiments were carried out in a completely randomized block design with five treatments: Fertilizer, AMF, AMF with Fertilizer, AMF with 1/2 Fertilizer, and the Control with non-inoculated and non-fertilized plants. The parameters evaluated were AMF root colonization and effect of inoculation on plant growth, nutrient absorption and yield. The results showed that AMF inoculation increased around 20 % of root colonization in both soybean and cotton; nutrients analyses in vegetal tissues showed increase of P and nitrogen content in inoculated plants, these results reflect in a higher yield. Our results showed that, AMF inoculation increase the effectiveness of fertilizer application in soybean and reduce the fertilizer dosage in cotton. PMID:27303367

  8. Effect of potassium and phosphorus on the transport of radiocesium by arbuscular mycorrhizal fungi

    Energy Technology Data Exchange (ETDEWEB)

    Gyuricza, Veronika; Dupre de Boulois, Herve [Universite catholique de Louvain, Unite de microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium); Declerck, Stephane, E-mail: stephan.declerck@uclouvain.b [Universite catholique de Louvain, Unite de microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium)

    2010-06-15

    Potassium, a chemical analogue of cesium, and phosphorus, an essential macronutrient transported by arbuscular mycorrhizal fungi (AMF), have been suggested to influence the transport of radiocesium by AMF. However, no study investigated the effects of increasing concentrations of both elements on the importance of this transport. Here, the arbuscular mycorrhizal-plant (AM-P) in vitro culture system associating Medicago truncatula plantlets with Glomus intraradices was used to evaluate this effect. Using three concentrations of K (0, 1, 10 mM) and two concentrations of P (30 and 3000 muM) added to a compartment only accessible to the AMF, we demonstrated that K and P individually and in combination significantly influenced radiocesium transport by AMF. Whilst increased concentration of K decreased the amount of radiocesium transported, the opposite was observed for P. Although the exact mechanisms involved need to be assessed, both elements were identified as important factors influencing the transport of radiocesium by AMF.

  9. Inoculant of arbuscular mycorrhizal fungi (Rhizophagus clarus) increase yield of soybean and cotton under field conditions

    OpenAIRE

    Martha Viviana Torres Cely; Admilton Gonçalves Oliveira; Vanessa Fogaça Freitas; Marcelo Benite de Luca; André Riedi Barazetti; Igor Matheus Oliveira Santos; Bárbara eGionco; Guilherme Volante Garcia; Cássio Egidio Cavenaghi Prete; Galdino eAndrade

    2016-01-01

    Nutrient availability is an important factor in crop production, and regular addition of chemical fertilizers is the most common practice to improve yield in agrosystems for intensive crop production. The use of some groups of microorganisms that have specific activity providing nutrients to plants is a good alternative, and arbuscular mycorrhizal fungi (AMF) enhance plant nutrition by providing especially phosphorus (P), improving plant growth and increasing crop production. Unfortunately, t...

  10. Glomus intraradices and Pacispora robiginia, species of arbuscular mycorrhizal fungi (Glomeromycota new for Poland

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2013-12-01

    Full Text Available Morphological characters of spores and mycorrhizae of Glomus intraradices, as well as spores of Pacispora robiginia, arbuscular mycorrhizal fungi of the phylum Glomeromycota, were described and illustrated. Additionally, the known distribution of these species in both Poland and other regions of the world was presented. Both the species were not so far recorded in Poland and this paper is the second report of the finding of P. robiginia in the

  11. Carbon cycling by arbuscular mycorrhizal fungi in soil-plant systems.

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Y.-G.; Miller, R. M.; Environmental Research; Chinese Academy of Sciences

    2003-09-01

    Arbuscular mycorrhizal fungi (AMF) play an important role in regulating carbon fluxes between the biosphere and the atmosphere. A recent study showed that live hyphae can turn over rapidly, in five to six days on average, suggesting that carbon flow to AMF hyphae might be respired back to the atmosphere quickly. However, that study gives a limited view of the residence time of AMF hyphae in soils. AMF hyphae can also contribute to soil carbon storage through other mechanisms.

  12. Common and divergent roles of plant hormones in nodulation and arbuscular mycorrhizal symbioses

    OpenAIRE

    Foo, Eloise; Ferguson, Brett J; Reid, James B.

    2014-01-01

    All of the classical plant hormones have been suggested to influence nodulation, including some that interact with the Autoregulation of Nodulation (AON) pathway. Leguminous plants strictly regulate the number of nodules formed through this AON pathway via a root-shoot-root loop that acts to suppress excessive nodulation. A related pathway, the Autoregulation of Mycorrhization (AOM) pathway controls the more ancient, arbuscular mycorrhizal (AM) symbiosis. A comparison of the published respons...

  13. Relationship between genotype and soil environment during colonization of poplar roots by mycorrhizal and endophytic fungi.

    Science.gov (United States)

    Karliński, Leszek; Rudawska, Maria; Kieliszewska-Rokicka, Barbara; Leski, Tomasz

    2010-06-01

    Poplars are among the few tree genera that can develop both ectomycorrhizal (ECM) and arbuscular (AM) associations; however, variable ratios of ECM/AM in dual mycorrhizal colonizations were observed in the roots of a variety of poplar species and hybrids. The objective of our study was to analyze the effect of internal and external factors on growth and dual AM and ECM colonization of poplar roots in three 12-15-year-old common gardens in Poland. We also analyzed the abundance of nonmycorrhizal fungal endophytes in the poplar roots. The Populus clones comprised black poplars (Populus deltoides and P. deltoides x Populus nigra), balsam poplars (Populus maximowiczii x Populus trichocarpa), and a hybrid of black and balsam poplars (P. deltoides x P. trichocarpa). Of the three sites that we studied, one was located in the vicinity of a copper smelter, where soil was contaminated with copper and lead. Poplar root tip abundance, mycorrhizal colonization, and soil fungi biomass were lower at this heavily polluted site. The total mycorrhizal colonization and the ratio of ECM and AM colonization differed among the study sites and according to soil depth. The influence of Populus genotype was significantly pronounced only within the individual study sites. The contribution of nonmycorrhizal fungal endophytes differed among the poplar clones and was higher at the polluted site than at the sites free of pollution. Our results indicate that poplar fine root abundance and AM and ECM symbiosis are influenced by environmental conditions. Further studies of different site conditions are required to characterize the utility of poplars for purposes such as the phytoremediation of polluted sites. PMID:19921284

  14. Arbuscular mycorrhizal fungal symbiosis with Sorbus torminalis does not vary with soil nutrients and enzyme activities across different sites

    Directory of Open Access Journals (Sweden)

    Moradi M

    2015-06-01

    Full Text Available Effects of soil chemical properties on arbuscular mycorrhizal fungal (AMF symbiosis with wild service tree (Sorbus torminalis L. Crantz were examined for study the rates of root colonization at three forest sites: Kheiroud, Lalis, and Takrin in northern Iran. Soil characteristics including pH, available phosphorus (P, potassium (K, organic matter, total nitrogen, acid and alkaline phosphatase activities, CaCO3, spore density (SD and AMF colonization of soil and root samples were analyzed. The study sites were investigated in spring and autumn to highlight the effects of soil chemical properties on AMF statues for better nurseries and reforestation management of this rare tree species in forests. Changes in soil pH, P, K, organic matter, total nitrogen, acid and alkaline phosphatase, CaCO3, SD, and AMF colonization of soil and root samples were analyzed at the study sites. K, pH, root colonization, SD and acid phosphatase activity showed no significant differences among sites in spring and autumn, while total nitrogen, P, organic matter and alkaline phosphatase activities showed significant differences among sites and seasons. AMF colonization rates were more than 51% and 32% of roots in spring and autumn, respectively. No correlation between root colonization and soil chemical parameters in spring and autumn were detected. There was no correlation between percentage of AM root colonization and SD nor other soil parameters in spring and autumn. SD and CaCO3 were significantly negatively correlated in spring and autumn. Despite differences in soil characteristics, the results showed that SD and root colonization were not significantly different among the sites. They also showed that wild service trees had strong symbiosis with AMF, while soil properties might not have a significant effect on this symbiosis. Therefore, colonized seedlings can be considered as an appropriated method for reforestation and conservation of this rare tree species.

  15. Effects of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species.

    Science.gov (United States)

    Caglar, S; Akgun, A

    2006-07-01

    The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions. PMID:17402238

  16. The arbuscular mycorrhizal fungi colonising roots and root nodules of New Zealand kauri Agathis australis.

    Science.gov (United States)

    Padamsee, Mahajabeen; Johansen, Renee B; Stuckey, S Alexander; Williams, Stephen E; Hooker, John E; Burns, Bruce R; Bellgard, Stanley E

    2016-05-01

    As the only endemic member in New Zealand of the ancient conifer family, Araucariaceae, Agathis australis is an ideal species to study putatively long-evolved mycorrhizal symbioses. However, little is known about A. australis root and nodular arbuscular mycorrhizal fungi (AMF), and how mycorrhizal colonisation occurs. We used light, scanning and transmission electron microscopy to characterise colonisation, and 454-sequencing to identify the AMF associated with A. australis roots and nodules. We interpreted the results in terms of the edaphic characteristics of the A. australis-influenced ecosystem. Representatives of five families of Glomeromycota were identified via high-throughput pyrosequencing. Imaging studies showed that there is abundant, but not ubiquitous, colonisation of nodules, which suggests that nodules are mostly colonised by horizontal transmission. Roots were also found to harbour AMF. This study is the first to demonstrate the multiple Glomeromycota lineages associated with A. australis including some that may not have been previously detected. PMID:27109376

  17. Soil solarization reduces arbuscular mycorrhizal fungi as a consequence of weed suppression.

    Science.gov (United States)

    Schreiner, P R; Ivors, K L; Pinkerton, J N

    2001-12-01

    Soil solarization, the process of heating soil by covering fields with clear plastic, is a promising method to reduce populations of soilborne pests and weeds without the use of pesticides. However, the destruction of beneficial organisms such as arbuscular mycorrhizal (AM) fungi also may occur, thereby reducing positive effects of solarization. We compared the effects of solarization and chemical fumigants on the survival of indigenous AM fungi in 1995 and 1996. The infectivity of AM fungi was monitored before and after solarization using a greenhouse bioassay with Sorghum bicolor L. for both years. AM colonization of roots was also monitored in the field 8 months after solarization in 1995. Weed densities were measured 8 months after treatment in 1996. Solarization increased the average daily soil temperature 6-10°C and the maximum soil temperature reached by 10-16°C (5-20 cm depth). Solarization did not reduce the infectivity of AM fungi immediately after the solarization period in either year, as determined by the greenhouse bioassay. Infectivity was greatly reduced in solarized plots 8 months after solarization (over winter) in both years as assessed in the field (1995) or with the greenhouse bioassay (1996). Fumigation with metam sodium at 930 l ha(-1) (350 kg active ingredient ha(-1)) reduced the infectivity of AM fungi in both years, and fumigation with methyl bromide at 800 kg ha(-1) eliminated infection by AM fungi. Solarization was as effective as methyl bromide and metam sodium at 930 l ha(-1) in controlling winter annual weeds measured 8 months after treatment. Solarization apparently reduced AM fungi in soil indirectly by reducing weed populations that maintained infective propagules over the winter. Fumigation with metam sodium or methyl bromide directly reduced AM fungi in soil.

  18. Variation of soil arbuscular mycorrhizal fungal communities across land use gradient

    Science.gov (United States)

    Moora, M.; Davison, J.; Metsis, M.; Öpik, M.; Vasar, M.; Zobel, M.

    2012-04-01

    Arbuscular mycorrhizal (AM) fungi (phylum Glomeromycota) colonize the roots of most terrestrial plants, facilitating mineral nutrient uptake from soil in exchange for plant-assimilated carbon. While investigating functional aspects of plant-AM fungi interactions has been a major focus of research, there is increasing interest in describing and explaining the distribution of AM fungal diversity. Different management practices has been shown to influence the AM fungal communities while more intense management can bring along the loss of AM fungal diversity. Such a loss may have negative consequences on ecosystem service delivery, primary production and soil sustainability. However, due to cryptic lifestyle of AM fungi, relatively few information is available about variability of diversity and composition of AM fungal communities in the soils from differently managed ecosystems. To study the variation of soil AM fungal communities in response to the land use intensity, replicated soil samples were collected along land use gradient from intensively managed agricultural fields, organic fields, forest plantations and managed natural forest to primeval forest in Estonia. Soil AM fungal communities were described using molecular tools: DNA extraction, amplicon isolation and 454 large scale parallel pyrosequencing. Glomeromycota sequences were amplified using the SSU rDNA primers NS31 and AML2. We shall analyse and describe AM fungal community changes along land use intensity gradient and seek finding indicator taxa characteristic to particular land use types. We shall also address changes in the diversity of AM fungal taxa and check whether the decrease of diversity along land use intensity is a ubiquitous phenomenon.

  19. Isolation and phenotypic characterization of Lotus japonicus mutants specifically defective in arbuscular mycorrhizal formation.

    Science.gov (United States)

    Kojima, Tomoko; Saito, Katsuharu; Oba, Hirosuke; Yoshida, Yuma; Terasawa, Junya; Umehara, Yosuke; Suganuma, Norio; Kawaguchi, Masayoshi; Ohtomo, Ryo

    2014-05-01

    Several symbiotic mutants of legume plants defective in nodulation have also been shown to be mutants related to arbuscular mycorrhizal (AM) symbiosis. The origin of the AM symbiosis can be traced back to the early land plants. It has therefore been postulated that the older system of AM symbiosis was partially incorporated into the newer system of legume-rhizobium symbiosis. To unravel the genetic basis of the establishment of AM symbiosis, we screened about 34,000 plants derived from ethyl methanesulfonate (EMS)-mutagenized Lotus japonicus seeds by microscopic observation. As a result, three lines (ME778, ME966 and ME2329) were isolated as AM-specific mutants that exhibit clear AM-defective phenotypes but form normal effective root nodules with rhizobial infection. In the ME2329 mutant, AM fungi spread their hyphae into the intercellular space of the cortex and formed trunk hyphae in the cortical cells, but the development of fine branches in the arbuscules was arrested. The ME2329 mutant carried a nonsense mutation in the STR-homolog gene, implying that the line may be an str mutant in L. japonicus. On the ME778 and ME966 mutant roots, the entry of AM fungal hyphae was blocked between two adjacent epidermal cells. Occasionally, hyphal colonization accompanied by arbuscules was observed in the two mutants. The genes responsible for the ME778 and ME966 mutants were independently located on chromosome 2. These results suggest that the ME778 and ME966 lines are symbiotic mutants involved in the early stage of AM formation in L. japonicus.

  20. Organic Nitrogen-Driven Stimulation of Arbuscular Mycorrhizal Fungal Hyphae Correlates with Abundance of Ammonia Oxidizers

    Science.gov (United States)

    Bukovská, Petra; Gryndler, Milan; Gryndlerová, Hana; Püschel, David; Jansa, Jan

    2016-01-01

    Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM) hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum) associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR) using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment) were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N)-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass), while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer) and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples. Further

  1. Organic nitrogen-driven stimulation of arbuscular mycorrhizal fungal hyphae correlates with abundance of ammonia oxidizers

    Directory of Open Access Journals (Sweden)

    Petra eBukovská

    2016-05-01

    Full Text Available Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass, while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples

  2. 孟加拉国Dinajpur农林复合区内不同树种和作物种中丛枝菌根分布和孢子群落多样性的研究%Biodiversity of arbuscular mycorrhizal colonization and spore population in different agroforestry trees and crop species growing in Dinajpur, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    M. A. U. Mridha; P. P. Dhar

    2007-01-01

    Biodiversity of arbuscular mycorrhizal colonization and spore population was investigated in different agroforestry trees and crop species collected from different locations of Dinajpur district of Bangladesh. Roots and rhizosphere soils of Albizia procera Benth., Capsicum frutescens L, Curcuma domestica Vahl., Dalbergia sissoo Roxb. and Swietenia macrophylla King. from Dashmail; C. domestica, D. sissoo, Eucalyptus camaldulensis Dehnn., Gmelina arborea (Roxb) DC and Oryza sativa L. from Kantaji and C. domestica, D. sissoo, Litchi chinensis Sonn. and O. sativa from Ramsagar were collected. Roots and soils were assessed following standard methods. The range of AM colonization was recorded 36%-79% from Dashmail. The highest AM colonization was recorded in C. frutescens (79%) and the lowest was in C. domestica (36%). The range of colonization was recorded as 33%-70% from Kantaji. The highest AM colonization was recorded in G. arborea (70%) and the lowest was in O. sativa (33%). The range of AM colonization was recorded as 35%-70% from Ramsagar. The highest AM colonization was recorded in D. sissoo (70%) and the lowest was in O. sativa (35%). Arbuscular mycorrhizal spore population varied from 54 to 140/100g dry soil in the soils from Dashmail. The highest was in the soils of D. sissoo (140) and the lowest was in C. domestica (54). The spore population varied from 63 to 221 in Kantaji. The highest was in G. arborea (221) and the lowest was in O. sativa (63). The range population in Ramsagar varied from 69 to 160. The highest was recorded in D. sissoo (160) and the lowest was in L. chinensis (69). No significant relationship of soil pH and soil OM with AM colonization and with spore population was observed. Simpson's index of diversity (Ds) and Shannon's index of diversity- (Hs) were highest in the soil of D. sissoo from Kantaji and the lowest in the soils of O. sativa from Ramsagar. Biodiversity of AM colonization, spore population and the distribution of AM fungi in

  3. Growth and nutritional status of Brazilian wood species Cedrella fissilis and Anadenanthera peregrina in bauxite spoil in response to arbuscular mycorrhizal inoculation and substrate amendment

    Directory of Open Access Journals (Sweden)

    Tótola Marcos Rogério

    2000-01-01

    Full Text Available The growth of Cedrella fissilis Vell. (Cedro Rosa and of Anadenanthera peregrina Benth (Angico Vermelho in bauxite spoil was studied to evaluate their response to substrate amendment or to inoculation with arbuscular mycorrhizal fungi (AMF. The plants were grown in bauxite spoil, topsoil or spoil amended with either topsoil or compost, and inoculated with the AMF Acaulospora scrobiculata, Gigaspora margarita or Glomus etunicatum. Root colonization was highly dependent on the interaction plant-fungus-substrate. In C. fissilis, root colonization by Gigaspora margarita dropped from 75% in bauxite spoil to only 4% in topsoil. Contrarily, root colonization of A. peregrina by the same fungus increased from 48% in spoil to 60% in topsoil. Root colonization of C. fissilis in topsoil was lower than in the three other substrates. The opposite was observed for A. peregrina. Inoculation of the plants with Acaulospora scrobiculata or Glomus etunicatum was very effective in promoting plant growth. Plants of both C. fissilis and A. peregrina did not respond to amendments of bauxite spoil unless they were mycorrhizal. Also, a preferential partitioning of photosynthates to the shoots of A. peregrina inoculated with G. etunicatum or A. scrobiculata, and of C. fissilis inoculated with any of the three species of AMF was observed. C. fissilis showed a greater response to mycorrhizal inoculation than A. peregrina. The mean mycorrhizal efficiency (ME for dry matter production by C. fissilis was 1,847% for A. scrobiculata, 1,922% for G. etunicatum, and 119% for G. margarita. In A. peregrina, the ME was 249% for A. scrobiculata, 540% for G. etunicatum, and 50% for G. margarita. The effect of mycorrhizal inoculation on plant growth seems to be related in part to an enhanced phosphorus absorption by inoculated plants. Moreover, the efficiency with which the absorbed nutrients were used to produce plant biomass was much greater in plants inoculated with A. scrobiculata or

  4. The characterization of six auxin-induced tomato GH3 genes uncovers a member, SlGH3.4, strongly responsive to arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Liao, Dehua; Chen, Xiao; Chen, Aiqun; Wang, Huimin; Liu, Jianjian; Liu, Junli; Gu, Mian; Sun, Shubin; Xu, Guohua

    2015-04-01

    In plants, the GH3 gene family is widely considered to be involved in a broad range of plant physiological processes, through modulation of hormonal homeostasis. Multiple GH3 genes have been functionally characterized in several plant species; however, to date, limited works to study the GH3 genes in tomato have been reported. Here, we characterize the expression and regulatory profiles of six tomato GH3 genes, SlGH3.2, SlGH3.3, SlGH3.4, SlGH3.7, SlGH3.9 and SlGH3.15, in response to different phytohormone applications and arbuscular mycorrhizal (AM) fungal colonization. All six GH3 genes showed inducible responses to external IAA, and three members were significantly up-regulated in response to AM symbiosis. In particular, SlGH3.4, the transcripts of which were barely detectable under normal growth conditions, was strongly activated in the IAA-treated and AM fungal-colonized roots. A comparison of the SlGH3.4 expression in wild-type plants and M161, a mutant with a defect in AM symbiosis, confirmed that SlGH3.4 expression is highly correlated to mycorrhizal colonization. Histochemical staining demonstrated that a 2,258 bp SlGH3.4 promoter fragment could drive β-glucuronidase (GUS) expression strongly in root tips, steles and cortical cells of IAA-treated roots, but predominantly in the fungal-colonized cells of mycorrhizal roots. A truncated 654 bp promoter failed to direct GUS expression in IAA-treated roots, but maintained the symbiosis-induced activity in mycorrhizal roots. In summary, our results suggest that a mycorrhizal signaling pathway that is at least partially independent of the auxin signaling pathway has evolved for the co-regulation of the auxin- and mycorrhiza-activated GH3 genes in plants. PMID:25535196

  5. Diversity and Spatial Structure of Belowground Plant–Fungal Symbiosis in a Mixed Subtropical Forest of Ectomycorrhizal and Arbuscular Mycorrhizal Plants

    OpenAIRE

    Toju, Hirokazu; Sato, Hirotoshi; Tanabe, Akifumi S

    2014-01-01

    Plant–mycorrhizal fungal interactions are ubiquitous in forest ecosystems. While ectomycorrhizal plants and their fungi generally dominate temperate forests, arbuscular mycorrhizal symbiosis is common in the tropics. In subtropical regions, however, ectomycorrhizal and arbuscular mycorrhizal plants co-occur at comparable abundances in single forests, presumably generating complex community structures of root-associated fungi. To reveal root-associated fungal community structure in a mixed for...

  6. Evaluation of Arbuscular Mycorrhizal Fungi Capacity to Alleviate Abiotic Stress of Olive (Olea europaea L.) Plants at Different Transplant Conditions

    Science.gov (United States)

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth. PMID:24688382

  7. Genome-wide analysis of copper, iron and zinc transporters in the arbuscular mycorrhizal fungus Rhizophagus irregularis

    Science.gov (United States)

    Tamayo, Elisabeth; Gómez-Gallego, Tamara; Azcón-Aguilar, Concepción; Ferrol, Nuria

    2014-01-01

    Arbuscular mycorrhizal fungi (AMF), belonging to the Glomeromycota, are soil microorganisms that establish mutualistic symbioses with the majority of higher plants. The efficient uptake of low mobility mineral nutrients by the fungal symbiont and their further transfer to the plant is a major feature of this symbiosis. Besides improving plant mineral nutrition, AMF can alleviate heavy metal toxicity to their host plants and are able to tolerate high metal concentrations in the soil. Nevertheless, we are far from understanding the key molecular determinants of metal homeostasis in these organisms. To get some insights into these mechanisms, a genome-wide analysis of Cu, Fe and Zn transporters was undertaken, making use of the recently published whole genome of the AMF Rhizophagus irregularis. This in silico analysis allowed identification of 30 open reading frames in the R. irregularis genome, which potentially encode metal transporters. Phylogenetic comparisons with the genomes of a set of reference fungi showed an expansion of some metal transporter families. Analysis of the published transcriptomic profiles of R. irregularis revealed that a set of genes were up-regulated in mycorrhizal roots compared to germinated spores and extraradical mycelium, which suggests that metals are important for plant colonization. PMID:25352857

  8. Response of Solanum melongena L. to Inoculation with Arbuscular Mycorrhizal Fungi under Low and High Phosphate Condition

    Directory of Open Access Journals (Sweden)

    Irfan AZIZ

    2011-08-01

    Full Text Available Solanum melongena L. a medicinally and economically important crop plants were grown in polythene bags. The effect of mycorrhizal inoculation (Glomus mosseae and increasing phosphate levels on the expression of the photosynthetic activity in terms of chlorophyll content. Antioxidant enzymes like peroxidase, polyphenol oxidase, root acid and alkaline phosphatase activity of Solanum melongena were evaluated. The experimental design was entirely at CRBD with eight treatments with three levels of phosphate (50,100,150 mg kg-1 of soil. Root colonization ranged from 50.33% to 67.33% . The activity of the studied antioxidant enzymes were found to be increased in arbuscular mycorrhizal (AM Solanum plants. Root phosphatase activity was greater in 100 and 150 mg phosphate level in AM treated than non AM treated Solanum plants. Besides, only AM treated plants of Solanum reflected increase in total chlorophyll content as compared to non AM plants. This work suggests that the mycorrhiza helps Solanum plants to perform better in low and high phosphate level by enhancing antioxidant enzyme activity, acid and alkaline phosphatase activity and total chlorophyll content.

  9. The arbuscular mycorrhizal fungus Glomus mosseae gives contradictory effects on phosphorus and arsenic acquisition by Medicago sativa Linn

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baodong [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Xiao Xueyi [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhu Yongguan [Department of Soil Environmental Sciences/State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)]. E-mail: ygzhu@rcees.ac.en; Smith, F. Andrew [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia); Miao Xie, Z. [Department of Environmental Science and Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Smith, Sally E. [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, South Australia 5005 (Australia)

    2007-07-01

    Mycorrhizal fungi may play an important role in protecting plants against arsenic (As) contamination. However, little is known about the direct and indirect involvement of arbuscular mycorrhizal fungi (AMF) in detoxification mechanisms. A compartmented pot cultivation system ('cross-pots') is used here to investigate the roles of AMF Glomus mosseae in plant phosphorus (P) and As acquisition by Medicago sativa, and P-As interactions. The results indicate that fungal colonization dramatically increased plant dry weight by a factor of around 6, and also substantially increased both plant P and As contents (i.e. total uptake). Irrespective of P and As addition levels, AM plants had shoot and root P concentrations 2 fold higher, but As concentrations significantly lower, than corresponding uninoculated controls. The decreased shoot As concentrations were largely due to 'dilution effects' that resulted from stimulated growth of AM plants and reduced As partitioning to shoots. The study provides further evidence for the protective effects of AMF on host plants against As contamination, and have uncovered key aspects of underlying mechanisms. The possible application of AMF in remediation practices is discussed.

  10. Role of arbuscular mycorrhizal fungus Rhizophagus custos in the dissipation of PAHs under root-organ culture conditions

    International Nuclear Information System (INIS)

    Polycyclic aromatic hydrocarbons (PAHs) are one of the most common contaminants in soil. Arbuscular mycorrhizal (AM) fungi make host plants resistant to pollutants. This study aims to evaluate the impact of anthracene, phenanthrene and dibenzothiophene on the AM fungus Rhizophagus custos, isolated from soil contaminated by heavy metals and PAHs, under monoxenic conditions. We found a high level of tolerance in R. custos to the presence of PAHs, especially in the case of anthracene, in which no negative effect on AM-colonized root dry weight (root yield) was observed, and also a decrease in the formation of anthraquinone was detected. Increased PAH dissipation in the mycorrhizal root culture medium was observed; however, dissipation was affected by the level of concentration and the specific PAH, which lead us to a better understanding of the possible contribution of AM fungi, and in particular R. custos, to pollutant removal. -- Highlights: •The AM fungus R. custos contributes to PAH dissipation and removal from the medium. •R. custos showed high levels of tolerance to high concentrations of anthracene. •Phenanthrene negatively affects the functionality of the symbiosis. •R. custos accumulates PAHs in spores and extraradical mycelia. •R. custos is able to prevent PAHs from entering roots. -- The AM fungus Rhizophagus custos is involved in PAH dissipation in absence of other microorganisms and could be potentially effective in protecting anthracene exposed plants

  11. Evaluation of arbuscular mycorrhizal fungi capacity to alleviate abiotic stress of olive (Olea europaea L.) plants at different transplant conditions.

    Science.gov (United States)

    Bompadre, María Josefina; Pérgola, Mariana; Fernández Bidondo, Laura; Colombo, Roxana Paula; Silvani, Vanesa Analía; Pardo, Alejandro Guillermo; Ocampo, Juan Antonio; Godeas, Alicia Margarita

    2014-01-01

    The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.

  12. Evaluation of Arbuscular Mycorrhizal Fungi Capacity to Alleviate Abiotic Stress of Olive (Olea europaea L. Plants at Different Transplant Conditions

    Directory of Open Access Journals (Sweden)

    María Josefina Bompadre

    2014-01-01

    Full Text Available The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF. AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains of Rhizophagus irregularis (GC2 and GA5 in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.

  13. Do fungivores trigger the transfer of protective metabolites from host plants to arbuscular mycorrhizal hyphae?

    Science.gov (United States)

    Duhamel, Marie; Pel, Roel; Ooms, Astra; Bücking, Heike; Jansa, Jan; Ellers, Jacintha; van Straalen, Nico M; Wouda, Tjalf; Vandenkoornhuyse, Philippe; Kiers, E Toby

    2013-09-01

    A key objective in ecology is to understand how cooperative strategies evolve and are maintained in species networks. Here, we focus on the tri-trophic relationship between arbuscular mycorrhizal (AM) fungi, host plants, and fungivores to ask if host plants are able to protect their mutualistic mycorrhizal partners from being grazed. Specifically, we test whether secondary metabolites are transferred from hosts to fungal partners to increase their defense against fungivores. We grew Plantago lanceolata hosts with and without mycorrhizal inoculum, and in the presence or absence of fungivorous springtails. We then measured fungivore effects on host biomass and mycorrhizal abundance (using quantitative PCR) in roots and soil. We used high-performance liquid chromatography to measure host metabolites in roots, shoots, and hyphae, focusing on catalpol, aucubin, and verbascoside. Our most striking result was that the metabolite catalpol was consistently found in AM fungal hyphae in host plants exposed to fungivores. When fungivores were absent, catalpol was undetectable in hyphae. Our results highlight the potential for plant-mediated protection of the mycorrhizal hyphal network. PMID:24279273

  14. Chromium immobilization by extra- and intraradical fungal structures of arbuscular mycorrhizal symbioses.

    Science.gov (United States)

    Wu, Songlin; Zhang, Xin; Sun, Yuqing; Wu, Zhaoxiang; Li, Tao; Hu, Yajun; Lv, Jitao; Li, Gang; Zhang, Zhensong; Zhang, Jing; Zheng, Lirong; Zhen, Xiangjun; Chen, Baodong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi can enhance plant Cr tolerance through immobilizing Cr in mycorrhizal roots. However, the detailed processes and mechanisms are unclear. The present study focused on cellular distribution and speciation of Cr in both extraradical mycelium (ERM) and mycorrhizal roots exposed to Cr(VI) by using field emission scanning electron microscopy equipped with energy dispersive X-ray spectrometer (FE-SEM-EDS), scanning transmission soft X-ray microscopy (STXM) and X-ray absorption fine structure (XAFS) spectroscopy techniques. We found that amounts of particles (possibly extracellular polymeric substances, EPS) were produced on the AM fungal surface upon Cr(VI) stress, which contributed greatly to Cr(VI) reduction and immobilization. With EDS of the surface of AM fungi exposed to various Cr(VI) levels, a positive correlation between Cr and P was revealed, suggesting that phosphate groups might act as counter ions of Cr(III), which was also confirmed by the XAFS analysis. Besides, STXM and XAFS analyses showed that Cr(VI) was reduced to Cr(III) in AM fungal structures (arbuscules, intraradical mycelium, etc.) and cell walls in mycorrhizal roots, and complexed possibly with carboxyl groups or histidine analogues. The present work provided evidence of Cr immobilization on fungal surface and in fungal structures in mycorrhizal roots at a cellular level, and thus unraveled the underlying mechanisms by which AM symbiosis immobilize Cr. PMID:27209517

  15. Chromium immobilization by extra- and intraradical fungal structures of arbuscular mycorrhizal symbioses.

    Science.gov (United States)

    Wu, Songlin; Zhang, Xin; Sun, Yuqing; Wu, Zhaoxiang; Li, Tao; Hu, Yajun; Lv, Jitao; Li, Gang; Zhang, Zhensong; Zhang, Jing; Zheng, Lirong; Zhen, Xiangjun; Chen, Baodong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi can enhance plant Cr tolerance through immobilizing Cr in mycorrhizal roots. However, the detailed processes and mechanisms are unclear. The present study focused on cellular distribution and speciation of Cr in both extraradical mycelium (ERM) and mycorrhizal roots exposed to Cr(VI) by using field emission scanning electron microscopy equipped with energy dispersive X-ray spectrometer (FE-SEM-EDS), scanning transmission soft X-ray microscopy (STXM) and X-ray absorption fine structure (XAFS) spectroscopy techniques. We found that amounts of particles (possibly extracellular polymeric substances, EPS) were produced on the AM fungal surface upon Cr(VI) stress, which contributed greatly to Cr(VI) reduction and immobilization. With EDS of the surface of AM fungi exposed to various Cr(VI) levels, a positive correlation between Cr and P was revealed, suggesting that phosphate groups might act as counter ions of Cr(III), which was also confirmed by the XAFS analysis. Besides, STXM and XAFS analyses showed that Cr(VI) was reduced to Cr(III) in AM fungal structures (arbuscules, intraradical mycelium, etc.) and cell walls in mycorrhizal roots, and complexed possibly with carboxyl groups or histidine analogues. The present work provided evidence of Cr immobilization on fungal surface and in fungal structures in mycorrhizal roots at a cellular level, and thus unraveled the underlying mechanisms by which AM symbiosis immobilize Cr.

  16. Effect of heavy metal contaminated shooting range soils on mycorrhizal colonization of roots and metal uptake by leek.

    Science.gov (United States)

    Mozafar, A; Ruh, R; Klingel, P; Gamper, H; Egli, S; Frossard, E

    2002-10-01

    We grew leek (Allium porrum) in soils of two shooting ranges heavily contaminated with heavy metals in the towns of Zuchwil and Oberuzwil in Switzerland as a bioassay to test the activity of arbuscular mycorrhizal (AM) fungi in these soils. Soil samples were taken from (1) front of the shooting house (HOUSE), (2) the area between house and target (FIELD) and (3) the berm (BACKSTOP). Samples of Ribwort plantain (Plantago lanceolata) growing naturally within the shooting ranges were also collected and the colonization of its roots by mycorrhizal fungi was measured. The number of AM spores in the soils was significantly reduced concomitant with the increase in the degree of soil contamination with metals. In Zuchwil, mycorrhizal fungi equally colonized roots of Ribwort plantain sampled from BACKSTOP and HOUSE. In Oberuzwil, however, plants from BACKSTOP had lower colonization when compared with those sampled from HOUSE. Colonization of leek was strongly reduced in the BACKSTOP soil of Zuchwil and slightly reduced in the BACKSTOP soil of Oberuzwil when compared with plants grown in respective HOUSE soil. Concentrations of Cd, Cr, Cu, Ni, Pb and Zn in the leaves of leek grown in the BACKSTOP soil was within the range considered toxic for human consumption. This points to the high degree of bioavailability of these metal in these soils. Significant decrease in the number of mycorrhizal spores in the BACKSTOP soils in Zuchwil and the low colonization of leek roots grown in these soils point to possible changes in the species diversity of mycorrhizal fungi in these soils. PMID:12413302

  17. The influence of pre-crop plants on the occurrence of arbuscular mycorrhizal fungi (Glomales and Phialophora graminicola associated with roots of winter XTriticosecale

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2014-08-01

    Full Text Available The influence of four pre-crop plant species on the occurrence of arbuscular mycorrhizal fungal (AMF, Glomales, Zygomycetes spores, mycorrhizae and Phialophora graminicola (Deacon Walker associated with roots of field-culuvated XTriticosecale Wittmack cv. Malno was investigated. The pre-crop plant species were Hordeum vutgare L., Lupinus luteus L., Pisum sativum L., and Vicia faba v. major Harz. Most spores and species of AMF were found when XTriticosecale was cultivated following P. sativum. Prior cropping with L. luteus caused the occurrence of the lowest number of spores among XTriticosecale roots. Mycorrhizal colonization of XTriticosecale was highest when planted after P. sativum and lowest when grown after L. luteus.

  18. Natural attenuation in a slag heap contaminated with cadmium: The role of plants and arbuscular mycorrhizal fungi

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Chavez, M.C. [Programa de Edafologia. Colegio de Postgraduados en Ciencias Agricolas, Campus Montecillo. Carretera Mexico-Texcoco, km 36.5. Montecillo, Texcoco, Mexico, 56230 (Mexico)], E-mail: carmeng@colpos.mx; Carrillo-Gonzalez, R.; Gutierrez-Castorena, M.C. [Programa de Edafologia. Colegio de Postgraduados en Ciencias Agricolas, Campus Montecillo. Carretera Mexico-Texcoco, km 36.5. Montecillo, Texcoco, Mexico, 56230 (Mexico)

    2009-01-30

    A field study of the natural attenuation occurring in a slag heap contaminated with high available cadmium was carried out. The aims of this research were: to determine plants colonizing this slag heap; to analyze colonization and morphological biodiversity of spores of arbuscular mycorrhizal fungi (AMF); to determine spore distribution in undisturbed samples; to know mycelium and glomalin abundance in the rhizosphere of these plants, and to investigate glomalin participation in Cd-stabilization. Forming vegetal islands, 22 different pioneering plant species from 11 families were colonizing the slag heap. The most common plants were species of Fabaceae, Asteraceae and Poaceae. Almost all plants were hosting AMF in their roots, and spores belonging to Gigaspora, Glomus, Scutellospora and Acaulospora species were observed. Micromorphological analysis showed that spores were related to decomposing vegetal residues and excrements, which means that mesofauna is contributing to their dispersion in the groundmass. Mycelium mass ranged from 0.11 to 26.3 mg/g, which contained between 13 and 75 mg of glomalin/g. Slag-extracted total glomalin was between 0.36 and 4.74 mg/g. Cadmium sequestered by glomalin extracted from either slag or mycelium was 0.028 mg/g. The ecological implication of these results is that organisms occupying vegetal patches are modifying mine residues, which contribute to soil formation.

  19. Natural attenuation in a slag heap contaminated with cadmium: The role of plants and arbuscular mycorrhizal fungi

    International Nuclear Information System (INIS)

    A field study of the natural attenuation occurring in a slag heap contaminated with high available cadmium was carried out. The aims of this research were: to determine plants colonizing this slag heap; to analyze colonization and morphological biodiversity of spores of arbuscular mycorrhizal fungi (AMF); to determine spore distribution in undisturbed samples; to know mycelium and glomalin abundance in the rhizosphere of these plants, and to investigate glomalin participation in Cd-stabilization. Forming vegetal islands, 22 different pioneering plant species from 11 families were colonizing the slag heap. The most common plants were species of Fabaceae, Asteraceae and Poaceae. Almost all plants were hosting AMF in their roots, and spores belonging to Gigaspora, Glomus, Scutellospora and Acaulospora species were observed. Micromorphological analysis showed that spores were related to decomposing vegetal residues and excrements, which means that mesofauna is contributing to their dispersion in the groundmass. Mycelium mass ranged from 0.11 to 26.3 mg/g, which contained between 13 and 75 mg of glomalin/g. Slag-extracted total glomalin was between 0.36 and 4.74 mg/g. Cadmium sequestered by glomalin extracted from either slag or mycelium was 0.028 mg/g. The ecological implication of these results is that organisms occupying vegetal patches are modifying mine residues, which contribute to soil formation

  20. Impact of weed control on arbuscular mycorrhizal fungi in a tropical agroecosystem: a long-term experiment.

    Science.gov (United States)

    Ramos-Zapata, José A; Marrufo-Zapata, Denis; Guadarrama, Patricia; Carrillo-Sánchez, Lilia; Hernández-Cuevas, Laura; Caamal-Maldonado, Arturo

    2012-11-01

    Cover crop species represent an affordable and effective weed control method in agroecosystems; nonetheless, the effect of its use on arbuscular mycorrhizal fungi (AMF) has been scantily studied. The goal of this study was to determine root colonization levels and AMF species richness in the rhizosphere of maize plants and weed species growing under different cover crop and weed control regimes in a long-term experiment. The treatment levels used were (1) cover of Mucuna deeringian (Muc), (2) "mulch" of Leucaena leucocephala (Leu), (3) "mulch" of Lysiloma latisiliquum (Lys), (4) herbicide (Her), (5) manual weeding (CD), (6) no weeding (SD), and (7) no maize and no weeding (B). A total of 18 species of AMF belonging to eight genera (Acaulospora, Ambispora, Claroideoglomus, Funneliformis, Glomus, Rhizophagus, Sclerocystis, and Scutellospora) were identified from trap cultures. Muc and Lys treatments had a positive impact on AMF species richness (11 and seven species, respectively), while Leu and B treatments on the other hand gave the lowest richness values (six species each). AMF colonization levels in roots of maize and weeds differed significantly between treatment levels. Overall, the use of cover crop species had a positive impact on AMF species richness as well as on the percentage of root colonized by AMF. These findings have important implications for the management of traditional agroecosystems and show that the use of cover crop species for weed control can result in a more diverse AMF community which should potentially increase crop production in the long run. PMID:22584877

  1. [Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils].

    Science.gov (United States)

    Wang, Fang; Guo, Weil; Ma, Peng-kun; Pan, Liang; Zhang, Jun

    2016-01-15

    A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Glomus aggregatum (GA) and Funneliformis mosseae (FM) on AM colonization rate, biomass, nutrient uptake, C: N: P stoichiometric and Ce uptake and transport by maize (Zea mays L.) grown in soils with different levels of Ce-contaminated (100, 500 and 1000 mg x kg(-1)). The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7. 12% to 74.47%. The increasing concentration of Ce in soils significantly decreased the mycorrhizal colonization rate, biomass, nutrition contents and transport rate of Ce from root to shoot of maize, and significantly increased C: P and N: P ratios and Ce contents in shoot and root of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C: N: P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soils, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoot and root in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and severe Ce-contaminated soils, and promoted the transport of Ce from root to shoot. The experiment demonstrates that AM fungi can alleviate toxic effects of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements. PMID

  2. [Effects of Arbuscular Mycorrhizal Fungi on the Growth and Ce Uptake of Maize Grown in Ce-contaminated Soils].

    Science.gov (United States)

    Wang, Fang; Guo, Weil; Ma, Peng-kun; Pan, Liang; Zhang, Jun

    2016-01-15

    A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Glomus aggregatum (GA) and Funneliformis mosseae (FM) on AM colonization rate, biomass, nutrient uptake, C: N: P stoichiometric and Ce uptake and transport by maize (Zea mays L.) grown in soils with different levels of Ce-contaminated (100, 500 and 1000 mg x kg(-1)). The aim was to provide basic data and technical support for the treatment of soils contaminated by rare earth elements. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 7. 12% to 74.47%. The increasing concentration of Ce in soils significantly decreased the mycorrhizal colonization rate, biomass, nutrition contents and transport rate of Ce from root to shoot of maize, and significantly increased C: P and N: P ratios and Ce contents in shoot and root of maize. Both AM fungi inoculations promoted the growth of maize, but the promoting role of FM was more significant than that of GA in severe Ce-contaminated soils. There were no significant differences in the growth of maize between two AM fungi in mild and moderate Ce-contaminated soils. Inoculation with AM fungi significantly improved nutritional status of maize by increasing nutrient uptake and decreasing C: N: P ratios. GA was more efficient than FM in enhancing nutrient uptake in mild and moderate Ce-contaminated soils, while FM was more efficient in severe Ce-contaminated soils. Moreover, inoculation with AM fungi significantly increased Ce contents of shoot and root in mild Ce-contaminated soils, but had no significant effect on Ce contents of maize in moderate and severe Ce-contaminated soils, and promoted the transport of Ce from root to shoot. The experiment demonstrates that AM fungi can alleviate toxic effects of Ce on plants and have a potential role in the phytoremediation of soils contaminated by rare earth elements.

  3. A meta-analysis of arbuscular mycorrhizal effects on plants grown under salt stress.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Boughattas, Sonia; Hu, Shuijin; Oh, Sang-Hyon; Sa, Tongmin

    2014-11-01

    Salt stress limits crop yield and sustainable agriculture in most arid and semiarid regions of the world. Arbuscular mycorrhizal fungi (AMF) are considered bio-ameliorators of soil salinity tolerance in plants. In evaluating AMF as significant predictors of mycorrhizal ecology, precise quantifiable changes in plant biomass and nutrient uptake under salt stress are crucial factors. Therefore, the objective of the present study was to analyze the magnitude of the effects of AMF inoculation on growth and nutrient uptake of plants under salt stress through meta-analyses. For this, data were compared in the context of mycorrhizal host plant species, plant family and functional group, herbaceous vs. woody plants, annual vs. perennial plants, and the level of salinity across 43 studies. Results indicate that, under saline conditions, AMF inoculation significantly increased total, shoot, and root biomass as well as phosphorous (P), nitrogen (N), and potassium (K) uptake. Activities of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase also increased significantly in mycorrhizal compared to nonmycorrhizal plants growing under salt stress. In addition, sodium (Na) uptake decreased significantly in mycorrhizal plants, while changes in proline accumulation were not significant. Across most subsets of the data analysis, identities of AMF (Glomus fasciculatum) and host plants (Acacia nilotica, herbs, woody and perennial) were found to be essential in understanding plant responses to salinity stress. For the analyzed dataset, it is concluded that under salt stress, mycorrhizal plants have extensive root traits and mycorrhizal morphological traits which help the uptake of more P and K, together with the enhanced production of antioxidant enzymes resulting in salt stress alleviation and increased plant biomass.

  4. Arbuscular mycorrhizal fungi (AMF) as bio protector agents against wilt induced by Verticillium spp. in pepper

    Energy Technology Data Exchange (ETDEWEB)

    Goicoechea, N.; Garmendia, I.; Sanchez-Diaz, M.; Aguirreolea, J.

    2010-07-01

    Verticillium dahliae Kleb. is a vascular pathogen that alters water status and growth of pepper plants and causes drastic reductions in yield. Its control is difficult because it can survive in field soil for several years. The application of arbuscular mycorrhizal fungi (AMF) as bio protector agents against V. dahliae is an alternative to the use of chemicals which, in addition, is more respectful with the environment. The establishment of the mutualistic association of plant roots and AMF involves a continuous cellular and molecular dialogue between both symbionts that includes the pre activation of plant defense responses that may enhance the resistance or tolerance of mycorrhizal plants to soil-borne pathogens. Some AMF can improve the resistance of Capsicum annuum L. against V. dahliae. This is especially relevant for pepper cultivars (i.e. cv. Piquillo) that exhibit high susceptibility to this pathogen. Compared with non-mycorrhizal plants, mycorrhizal pepper can exhibit more balanced antioxidant metabolism in leaves along the first month after pathogen inoculation, which may contribute to delay both the development of disease symptoms and the decrease of photosynthesis in Verticillium-inoculated plants with the subsequent benefit for yield. In stems, mycorrhizal pepper show earlier and higher deposition of lignin in xylem vessels than non mycorrhizal plants, even in absence of the pathogen. Moreover, AMF can induce new isoforms of acidic chitinases and superoxide dismutase in roots. Mycorrhizal-specific induction of these enzymatic activities together with enhanced peroxidase and phenylalanine ammonia-lyase in roots may also be involved in the bio protection of Verticillium-induced wilt in pepper by AMF. (Author) 81 refs.

  5. Arbuscular mycorrhiza of plants spontaneously colonizing the soda heap in Jaworzno (southern Poland

    Directory of Open Access Journals (Sweden)

    Ewa Gucwa-Przepióra

    2011-04-01

    Full Text Available The results of studies of the mycorrhizal status of plant species spontaneously established on the soda heap located in Jaworzno (Upper Silesia, Poland are presented. Additionally, the species of arbuscular fungi of the phylum Glomeromycota extracted from field-collected rhizosphere substrate samples of the heap are showed. Arbuscular mycorrhizae were described in 17 plant species. Five Glomus spp. were recognized in the spore populations of arbuscular fungi isolated. The investigation presented in this paper for the first time revealed Centaurea stoebe and Trifolium montanum to be hosts of arbuscular fungi.

  6. Regulation of plant growth, photosynthesis, antioxidation and osmosis by an arbuscular mycorrhizal fungus in watermelon seedlings under well-watered and drought conditions

    Directory of Open Access Journals (Sweden)

    Yanling eMo

    2016-05-01

    Full Text Available Drought stress has become an increasingly serious environmental issue that influences the growth and production of watermelon. Previous studies found that arbuscular mycorrhizal (AM colonization improved the fruit yield and water use efficiency of watermelon grown under water stress; however, the exact mechanisms remain unknown. In this study, the effects of Glomus versiforme symbiosis on the growth, physio-biochemical attributes, and stress-responsive gene expressions of watermelon seedlings grown under well-watered and drought conditions were investigated. The results showed that AM colonization did not significantly influence the shoot growth of watermelon seedlings under well-watered conditions but did promote root development irrespective of water treatment. Drought stress decreased the leaf relative water content and chlorophyll concentration, but to a lesser extent in the AM plants. Compared with the non-mycorrhizal seedlings, mycorrhizal plants had higher non-photochemical quenching values, which reduced the chloroplast ultrastructural damage in the mesophyll cells and thus maintained higher photosynthetic efficiency. Moreover, AM inoculation led to significant enhancements in the enzyme activities and gene expressions of SOD, CAT, APX, GR and MDHAR in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and O2- compared with non-mycorrhizal plants. Under drought stress, the soluble sugar and proline contents were significantly increased, and further enhancements were observed by pre-treating the drought-stressed plants with AM. Taken together, our findings indicate that mycorrhizal colonization enhances watermelon drought tolerance through a stronger root system, greater protection of photosynthetic apparatus, a more efficient antioxidant system and improved osmoregulation. This study contributes to advances in the knowledge of AM-induced drought tolerance.

  7. A molecular approach to study the arbuscular mycorrhizal fungi community in a typical Piedmont grapevine cultivar

    Science.gov (United States)

    Magurno, F.; Bughi Peruglia, G.; Lumini, E.; Bianciotto, V.; Balestrini, R.

    2009-04-01

    Viticulture and wine production represent one of the most relevant agro-food sectors for the Piedmont Region (Italy) in terms of value, with more than 400 millions € a year (12 % of total agricultural production of the Region and the 10 % of the national grape and wine production). The soil where grapevines (Vitis spp.) grow is one of the first parameters influencing the complex grapevine-wine chain. Arbuscular mycorrhizal fungi (AMFs), a main component of soil microbiota in most agrosystems, are considered crucial biomarkers of soil quality because of their biofertilisers role. As mutualistic symbionts, they colonize the roots of the majority of plants. Benefits in symbiosis are well showed as an improvement in shoot/root growth, mineral transport, water-stress tolerance and resistance to certain diseases. Grapevines roots are often heavily colonized by AMFs under field conditions and in some cases AMFs appear to be necessary for their normal growth and survival. Even so, little information are until now available about composition of AMFs communities living in the vineyards soil and in associations with grapevine roots, mainly related to morphological characterization. Vineyard of Nebbiolo, one of the most important Piedmont cultivar, was selected in order to study the AMFs community using a molecular approach. Soil samples and roots from an experimental vineyard located in Lessona (Biella, Piedmont, Italy) were analyzed using AM fungal-specific primers to partially amplify the small subunit (SSU) of the ribosomal DNA genes. Much more than 650 clones were sequenced. Phylogenetic analyses identified 32 OTUs from soil, clustered into Glomus groups Aa, Ab, Ad and B, Diversisporaceae and Gigasporaceae families. Thirteen OTUs from roots were determined, clustered into Glomus groups Ab, Ad and B, and Gigasporaceae family. In particular, Glomus group Ad was the best represented in both compartments, suggesting a correlation between intra and extra radical communities

  8. ARBUSCULAR MYCORRHIZAL FUNGI FROM THE RfflZOSPHERES OF SOYBEAN CROPS IN LAMPUNG AND WEST JAVA

    Directory of Open Access Journals (Sweden)

    K. KRAMADIBRATA

    1995-01-01

    Full Text Available The occurrence of arbuscular mycorrhizal (AM fungi in the rhizospheres of field-grown soybean crops in the provinces of Lampung and West Java was examined. Nineteen taxa of AM fungi were identified as follows: Acaulospora delicata, A. Foveata, A. rehmii, A. scrobiculata and A. tuberculata; Gigaspora cf. gigantea and Gigaspora sp. 1; Glomus clavisporum; Glomus cf. fasciculatum, Glomus micro-aggregatum, Glomus sp. 1, Glomus sp. 2, Glomus sp. 3 and Glomus sp. 4; Scutellospora cf. heterogama, Scutellospora cf. pellucida, Scutellospora sp. 1. Scutellospora sp.2. and Scutellospora sp. 3.

  9. Arsenic uptake in upland rice inoculated with a combination or single arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Chan, W F; Li, H; Wu, F Y; Wu, S C; Wong, M H

    2013-11-15

    A pot trial was conducted to investigate the role of arbuscular mycorrhizal fungi (AMF) on arsenic (As) uptake of upland rice (Oryza sativa L.) cultivar, Zhonghan 221; where the following 3 species of Glomus geosporum (Gg), G. mosseae (Gm) and G. versiforme (Gv) were applied as single or combined inoculations. In general, Gm significantly enhanced (p63% when grown in As80 soil. There was a significant difference (p 0.01) and total P (r = 0.002, p > 0.01) were observed.

  10. Succession of arbuscular mycorrhizal fungi in a deflation hollow of the Słowiński National Park, Poland

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    Mariusz Tadych

    2014-02-01

    Full Text Available In the years 1994-1995, the occurrence of arbuscular mycorrhizal fungi (AMF and arbuscular mycorrhizae (AM in eight successional stages of vegetation of a deflation hollow no. 12 of the Łeba Bar, Poland, was investigated. Early successional stages were colonized by members of the families Gramineae and Juncaceae, being gradually replaced by ericaceous plants in the middle and later stages and by trees in the most advanced stage corresponding to the Empetro nigri-Pinetum plant association. From the 96 soil samples collected, 21 species in three genera of AMF were recovered. The fungi most frequently found were members of the genus Acaulospora. The overall spore abundance, the species_ richness of AMF and the level of AM colonisation increased from stage 1 to reach a maximum in the middle stages and then gradually declined, being lowest in the forested stage 8. The values of the overall spore abundance and those of the abundances of the most frequently occurring AMF species strongly evidenced functioning in nature of the process of host-dependent differentiation of AMF communities. Of the five most numerously represented AMF species, the early colonizer and quickly diminishing in later successional stages was Glomus 107. The mid-late successor was A. koskei, and the latest - Glomus aggregatum. All measures of AMF presence negatively correlated with the content of organic C in the soil and most of them were negatively correlated with soil N-NO3 and P concentrations. In contrast, the occurrence of AMY and AM generally was positively correlated with soil pH and the K content of the soil.

  11. Colonization Characteristics of Arbuscular Mycorrhizal Fungi and Dark Septate Endophytes in Different Degree Pb-Zn Polluted Areas%不同程度铅锌污染区丛枝菌根真菌和深色有隔内生真菌侵染特征

    Institute of Scientific and Technical Information of China (English)

    班宜辉; 徐舟影; 杨玉荣; 刘洪光; 唐明

    2012-01-01

    The resource and distribution of arbuscular mycorrhizal fungi (AMF) and dark septate endo-phytes (DSE) in four sampling areas in Qiandongshan Pb-Zn mine, Fengxian County, Shaanxi Province, was investigated. (l)In the mine where the Pb and Zn concentrations were below the third level of national environmental quality standard, fifteen plant species were collected, and twelve of them were found establish dual symbiosis with AMF and DSE except for Pistacia chinensis ,Quercus variabilis and Rumesc aceto-sa. P. chinensis could only be infected by AMF, while Q. variabilis and R. acetosa could only be infected by DSE. However, the average AMF and DSE colonization of all plant species in the mine were low,only 32. 3% (AMF) and 25. 9% (DSE). In the slightly Pb and Zn polluted tailing wasteland, the average root colonization of AMF and DSE was 53. 3% and 38. 6%,respectively. In the moderately Pb polluted and severely Zn polluted tailing dam,the average AMF and DSE colonization was 68. 3% and 54. 2% .respectively. The average mycorrhizal colonization in tailing wasteland and tailing dam were higher than the control mine. In the severely Pb and Zn polluted abandoned smelter, the average AMF colonization decreased to 17. 6%,but the DSE colonization still maintained at 60. 3%. (2)The AMF spores in the four sites were maldistribution and the spore density per gram soil ranged from 0. 08 to 6. 84 and the average density per gram soil was 1. 5. After we investigated the AMF and DSE colonization status of the common plants, Sophora viciifolia , Macleaya cordata , Artemisia brachyloba , and Saussurea tsinlingensis , we found that slight and moderate pollution promoted the establishment of the symbiotic relationship between AMF and their hosts. However, severe pollution inhibited the infection; No significant relationship was found between AMF spore density and colonization;DSE colonization was significantly positive correlated with soil Zn concentration (r=0. 505,P<0. 05) ,but had no

  12. Arbuscular mycorrhizal fungi in soil and roots respond differently to phosphorus inputs in an intensively managed calcareous agricultural soil.

    Science.gov (United States)

    Liu, Wei; Zhang, Yunlong; Jiang, Shanshan; Deng, Yan; Christie, Peter; Murray, Philip J; Li, Xiaolin; Zhang, Junling

    2016-01-01

    Understanding the diversity and community structure of arbuscular mycorrhizal fungi (AMF) is important for potentially optimizing their role in mining phosphorus (P) in agricultural ecosystems. Here, we conduct a comprehensive study to investigate the vertical distribution of AMF in a calcareous field and their temporal structure in maize-roots with fertilizer P application over a three-year period. The results showed that soil available-P response to P fertilization but maize yields did not. Phosphorus fertilization had no-significant effect on richness of AMF except at greater soil-depths. High P-supply reduced root colonization while optimum-P tended to increase colonization and fungal richness on all sampling occasions. Crop phenology might override P-supply in determining the community composition of active root inhabiting fungi. Significant differences in the community structure of soil AMF were observed between the controls and P treatments in surface soil and the community shift was attributable mainly to available-P, N/P and pH. Vertical distribution was related mainly to soil electrical conductivity and Na content. Our results indicate that the structure of AMF community assemblages is correlated with P fertilization, soil depth and crop phenology. Importantly, phosphorus management must be integrated with other agricultural-practices to ensure the sustainability of agricultural production in salinized soils. PMID:27102357

  13. Effect of Arbuscular Mycorrhizal Fungi on the Growth and Polyphenol Profile of Marjoram, Lemon Balm, and Marigold.

    Science.gov (United States)

    Engel, Rita; Szabó, Krisztina; Abrankó, László; Rendes, Kata; Füzy, Anna; Takács, Tünde

    2016-05-18

    The aim of this study is to examine the effect of arbuscular mycorrhizal fungi (AMF) colonization on biomass, polyphenol profile, and content of economically important herbs. A pot experiment was performed with marjoram, lemon balm, and marigold applying a commercially available AMF mixture for inoculation. Major polyphenols were identified using HPLC-UV-ESI-qTOFMS on the basis of their UV-vis and mass spectral characteristics, and selected ones were quantified. We showed that AMF can provide different services for each herb. Marjoram had the highest level of fungal colonization (82 M%) followed by lemon balm (62 M%) and marigold (17 M%). AMF inoculation significantly increased the biomass of marjoram (1.5-fold), the number of marigold flowers (1.2-fold), and the yield of rosmarinic acid and lithospermic acid isomers of marjoram (1.5-fold) and lemon balm (1.2-fold). Therefore, the quantity and quality of plant material could be improved by the application of optimized AMF inoculum. PMID:27096876

  14. Effect of different arbuscular mycorrhizal fungi on growth and physiology of maize at ambient and low temperature regimes.

    Science.gov (United States)

    Chen, Xiaoying; Song, Fengbin; Liu, Fulai; Tian, Chunjie; Liu, Shengqun; Xu, Hongwen; Zhu, Xiancan

    2014-01-01

    The effect of four different arbuscular mycorrhizal fungi (AMF) on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT) and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress.

  15. Effect of Different Arbuscular Mycorrhizal Fungi on Growth and Physiology of Maize at Ambient and Low Temperature Regimes

    Directory of Open Access Journals (Sweden)

    Xiaoying Chen

    2014-01-01

    Full Text Available The effect of four different arbuscular mycorrhizal fungi (AMF on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress.

  16. Effects of arbuscular mycorrhizal fungi on leaf solutes and root absorption areas of trifoliate orange seedlings under water stress conditions

    Institute of Scientific and Technical Information of China (English)

    WU Qiangsheng; XIA Renxue

    2006-01-01

    The effects of the arbuscular mycorrhizal (AM)fungus Glomus mosseae on plant growth,leaf solutes and root absorption area of trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings were studied in potted culture under water stress conditions.Inoculation with G.mosseae increased plant height,stem diameter,leaf area,shoot dry weight,root dry weight and plant dry weight,when the soil water content was 20%,16% and 12%.AM inoculation also promoted the active and total absorption area of root system and absorption of phosphorus from the rhizosphere,enhanced the content of soluble sugar in leaves and roots,and reduced proline content in leaves.AM seedlings had higher plant water use efficiency and higher drought tolerance than non-AM seedlings.Effects of G.mosseae inoculation on trifoliate orange seedlings under 20% and 16% soil water content were more significant than under 12% soil water content.AM infection was severely restrained by 12% soil water content.Thus,effects of AM fungi on plants were probably positively related to the extent of root colonization by AM fungi.The mechanism of AM fungi in enhancing drought resistance of host plants ascribed to greater osmotic adjustment and greater absorption area of root system by AM colonization.

  17. The symbiosis with the arbuscular mycorrhizal fungus Rhizophagus irregularis drives root water transport in flooded tomato plants.

    Science.gov (United States)

    Calvo-Polanco, Monica; Molina, Sonia; Zamarreño, Angel María; García-Mina, Jose María; Aroca, Ricardo

    2014-05-01

    It is known that the presence of arbuscular mycorrhizal fungi within the plant roots enhances the tolerance of the host plant to different environmental stresses, although the positive effect of the fungi in plants under waterlogged conditions has not been well studied. Tolerance of plants to flooding can be achieved through different molecular, physiological and anatomical adaptations, which will affect their water uptake capacity and therefore their root hydraulic properties. Here, we investigated the root hydraulic properties under non-flooded and flooded conditions in non-mycorrhizal tomato plants and plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. Only flooded mycorrhizal plants increased their root hydraulic conductivity, and this effect was correlated with a higher expression of the plant aquaporin SlPIP1;7 and the fungal aquaporin GintAQP1. There was also a higher abundance of the PIP2 protein phoshorylated at Ser280 in mycorrhizal flooded plants. The role of plant hormones (ethylene, ABA and IAA) in root hydraulic properties was also taken into consideration, and it was concluded that, in mycorrhizal flooded plants, ethylene has a secondary role regulating root hydraulic conductivity whereas IAA may be the key hormone that allows the enhancement of root hydraulic conductivity in mycorrhizal plants under low oxygen conditions.

  18. Status and diversity of arbuscular mycorrhizal fungi and its role in natural regeneration on limestone mined spoils

    Directory of Open Access Journals (Sweden)

    ANUJ KUMAR SINGH

    2011-04-01

    Full Text Available Singh AK, Jamaluddin (2011 Status and diversity of arbuscular mycorrhizal fungi and its role in natural regeneration on limestone mined spoils. Biodiversitas 12: 107-111. Limestone mined spoils are devoid of adequate population of beneficial microbial flora. Arbuscular mycorrhizal fungi (AMF are very important constituent of plant- soil-microbe system. In mined spoils the population of AMF is greatly reduced and hence the spoils become very inhospitable for establishment of vegetation. In the present investigation, status of AMF population and its effect on natural regeneration process is studied. It is well known fact that the arbuscular mycorrhizal fungi play very important role in establishment of vegetation in degraded lands. Plantation of seedlings inoculated with arbuscular mycorrhizal fungi provide favorable soil conditions for naturally growing vegetation in the mined overburden spoils. Physico-chemical properties of soil are converted suitable for planted species and thus it allows other species to grow and also provide shade to protect the herbaceous vegetation. Introduction of plant species attracts immigration of other species and if they established, may result into a very distinctive floral cover on disturbed lands. Thus, invasion of native plant species along with planted species may play a significant role in increasing the plant diversity on mined

  19. Chemotactic response of plant-growth-promoting bacteria towards roots of vesicular-arbuscular mycorrhizal tomato plants.

    Science.gov (United States)

    Gupta Sood, Sushma

    2003-08-01

    The chemotactic responses of the plant-growth-promoting rhizobacteria Azotobacter chroococcum and Pseudomonas fluorescens to roots of vesicular-arbuscular mycorrhizal (Glomus fasciculatum) tomato plants were determined. A significantly (P=0.05) greater number of bacterial cells of wild strains were attracted towards vesicular-arbuscular mycorrhizal tomato roots compared to non-vesicular-arbuscular mycorrhizal tomato roots. Substances exuded by roots served as chemoattractants for these bacteria. P. fluorescens was strongly attracted towards citric and malic acids, which were predominant constituents in root exudates of tomato plants. A. chroococcum showed a stronger response towards sugars than amino acids, but the response was weakest towards organic acids. The effects of temperature, pH, and soil water matric potential on bacterial chemotaxis towards roots were also investigated. In general, significantly (P=0.05) greater chemotactic responses of bacteria were observed at higher water matric potentials (0, -1, and -5 kPa), slightly acidic to neutral pH (6, 6.5 and 7), and at 20-30 degrees C (depending on the bacterium) than in other environmental conditions. It is suggested that chemotaxis of P. fluorescens and A. chroococcum towards roots and their exudates is one of the several steps in the interaction process between bacteria and vesicular-arbuscular mycorrhizal roots. PMID:19719591

  20. The effect of agricultural practices on the development of indigenous arbuscular mycorrhizal fungi. II. Studies in experimental microcorms

    NARCIS (Netherlands)

    Boddington, C.L.; Dodd, J.C.

    2000-01-01

    Two glasshouse experiments were performed to assess the development and metabolic activity of mycorrhizas formed by isolates of arbuscular mycorrhizal fungi (AMF) from three different genera, Acaulospora, Gigaspora and Glomus on Desmodium ovalifolium L. plants. In the first experiment the effect of

  1. Influence of native arbuscular mycorrhizal fungi on growth, nutrition and phytochemical constituents of Catharanthus roseus (L.) G. Don.

    OpenAIRE

    Rajendran Srinivasan; Chinnavenkataraman Govindasamy

    2014-01-01

    Objective: To study the isolation, identification, mass production and the effect of native arbuscular mycorrhizal fungi (AM fungi) on growth parameters of the Catharanthus roseus (C. roseus). Methods: A total of nine different AM fungi species such as Acaulospora scrobiculata, Acaulospora marrowae, Glomus aggregatum (G. aggregatum), Glomus fasciculatum, Glomus geosporum, Gigaspora margarita, Gigaspora nigra, Scutellospora heterogama and Scutellospora pellucida were isolated...

  2. Influence of cultivation regime of an arbuscular mycorrhizal fungal isolate on its symbiotic efficacy in phyto restoration of disturbed ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R. S.; Vosatka, M.; Castro, P. M. L.; Dodd, J. C.

    2009-07-01

    Arbuscular mycorrhizal fungi (AMF), from the Phylum Glomeromycota, are a group of soil organisms that forms symbiotic associations with plant roots and can contribute to increase plant biomass and promote phyto restoration of disturbed ecosystems. The influence of cultivation regime of a Glomus geosporum isolate, obtained from a highly alkaline anthropogenic sediment, on its symbiotic efficacy was investigated. (Author)

  3. Clonal diversity and population genetic structure of arbuscular mycorrhizal fungi (Glomus spp.) studied by multilocus genotyping of single spores

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    A nested multiplex PCR (polymerase chain reaction) approach was used for multilocus genotyping of arbuscular mycorrhizal fungal populations. This method allowed us to amplify multiple loci from Glomus single spores in a single PCR amplification. Variable introns in the two protein coding genes Gm...

  4. Soil bacteria respond to presence of roots but not to mycelium of arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Olsson, P.A.; Bååth, E.; Jakobsen, I.;

    1996-01-01

    Arbuscular mycorrhizal (AM) cucumber seedlings and uncolonized controls were grown in growth chambers which allowed separation of compartments with roots from compartments with the extraradical mycelium alone. Two fungi, Glomus invermaium Hall and G. caledonium (Nicol. and Gerd.) Trappe and Gerde......Arbuscular mycorrhizal (AM) cucumber seedlings and uncolonized controls were grown in growth chambers which allowed separation of compartments with roots from compartments with the extraradical mycelium alone. Two fungi, Glomus invermaium Hall and G. caledonium (Nicol. and Gerd.) Trappe...... and Gerdemann, were used. Bacterial numbers (direct and viable count) and activities (thymidine incorporation) were highest in the root compartment, but were not affected by the AM mycelium after 30 days of plant growth. The soil was stored after harvest for 16 d at 13°C to study the effect of disconnected......) pattern. The bacteria specific PLFAs cy17:0 and cy19:0 increased in both experiments in the root compartments. The PLFAs 15:0 and 17:0, which are usually considered to be bacteria specific, also increased due to the presence of roots, but it was shown that these fatty acids were present in aseptically...

  5. Prospects for arbuscular mycorrhizal fungi (AMF) to assist in phytoremediation of soil hydrocarbon contaminants.

    Science.gov (United States)

    Rajtor, Monika; Piotrowska-Seget, Zofia

    2016-11-01

    Arbuscular mycorrhizal fungi (AMF) form mutualistic associations with the roots of 80-90% of vascular plant species and may constitute up to 50% of the total soil microbial biomass. AMF have been considered to be a tool to enhance phytoremediation, as their mycelium create a widespread underground network that acts as a bridge between plant roots, soil and rhizosphere microorganisms. Abundant extramatrical hyphae extend the rhizosphere thus creating the hyphosphere, which significantly increases the area of a plant's access to nutrients and contaminants. The paper presents and evaluates the role and significance of AMF in phytoremediation of hydrocarbon contaminated sites. We focused on (1) an impact of hydrocarbons on arbuscular mycorrhizal symbiosis, (2) a potential of AMF to enhance phytoremediation, (3) determinants that influence effectiveness of hydrocarbon removal from contaminated soils. This knowledge may be useful for selection of proper plant and fungal symbionts and crucial to optimize environmental conditions for effective AMF-mediated phytoremediation. It has been concluded that three-component phytoremediation systems based on synergistic interactions between plant roots, AMF and hydrocarbon-degrading microorganisms demonstrated high effectiveness in dissipation of organic pollutants in soil. PMID:27487095

  6. Grassland Degradation Decrease the Diversity of Arbuscular Mycorrhizal Fungi Species in Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Xiao-Bu CAI

    2014-12-01

    Full Text Available Arbuscular mycorrhizal (AM fungi play a vital role in restoration of an ecosystem. Grassland degradation in alpine steppe is severe, but the influence of grassland degradation on AM fungi composition in Tibetan Plateau is still not well understood. This research studied the diversity of arbuscular mycorrhizal fungi in degraded alpine steppe, dominated by Stipa purpurea. The results showed that the species richness and abundance of AM fungi in degraded grasslands significantly decreased. In different typical grasslands species, diversity of AM fungi genus Glomus was much higher than other genera (Acaulospora and Scutellospora. Compared with normal grassland, the AM fungal species diversity in moderately degraded grassland decreased by 30%, but in lightly degraded and severely degraded grassland, it highly increased with 15.3% and 13.3%, respectively. The species diversity of genus Glomus in moderately degraded grassland and lightly degraded grassland were higher than for normal grassland. Significant differences were observed in a relative abundance of common dominant species among different degraded grasslands. The proportion of dominant species highly increased with the aggravation of grassland degradation. The results suggest that the grassland mild degradation increased the adaptability and stress resistance of species.

  7. Arbuscular mycorrhizal association enhances drought tolerance potential of promising bioenergy grass (Saccharum arundinaceum retz.).

    Science.gov (United States)

    Mirshad, P P; Puthur, Jos T

    2016-07-01

    The influence of arbuscular mycorrhizal fungi (AMF) (Glomus spp.) on some physiological and biochemical characteristics of bioenergy grass Saccharum arundinaceum subjected to drought stress was studied. The symbiotic association of Glomus spp. was established with S. arundinaceum, a potential bioenergy grass as evident from the increase in percentage of root infection and distribution frequency of vesicles when compared with non-arbuscular mycorrhizal plants. AMF-treated plants exhibited an enhanced accumulation of osmolytes such as sugars and proline and also increased protein content under drought. AMF association significantly increased the accumulation of non-enzymatic antioxidants like phenols, ascorbate and glutathione as well as enhanced the activities of antioxidant enzymes such as SOD (superoxide dismutase), APX (ascorbate peroxidase) and GPX (guaiacol peroxidase) resulting in reduced lipid peroxidation in S. arundinaceum. AMF symbiosis also ameliorated the drought-induced reduction of total chlorophyll content and activities of photosystem I and II. The maximum quantum efficiency of PS II (F v/F m) and potential photochemical efficiency (F v/F o) were higher in AMF plants as compared to non-AMF plants under drought stress. These results indicate that AMF association alleviate drought stress in S. arundinaceum by the accumulation of osmolytes and non-enzymatic antioxidants and enhanced activities of antioxidant enzymes, and hence, the photosynthetic efficiency is improved resulting in increased biomass production. AMF association with energy grasses also improves the acclimatization of S. arundinaceum for growing in marginal lands of drought-affected soils.

  8. Arbuscular mycorrhizal association enhances drought tolerance potential of promising bioenergy grass (Saccharum arundinaceum retz.).

    Science.gov (United States)

    Mirshad, P P; Puthur, Jos T

    2016-07-01

    The influence of arbuscular mycorrhizal fungi (AMF) (Glomus spp.) on some physiological and biochemical characteristics of bioenergy grass Saccharum arundinaceum subjected to drought stress was studied. The symbiotic association of Glomus spp. was established with S. arundinaceum, a potential bioenergy grass as evident from the increase in percentage of root infection and distribution frequency of vesicles when compared with non-arbuscular mycorrhizal plants. AMF-treated plants exhibited an enhanced accumulation of osmolytes such as sugars and proline and also increased protein content under drought. AMF association significantly increased the accumulation of non-enzymatic antioxidants like phenols, ascorbate and glutathione as well as enhanced the activities of antioxidant enzymes such as SOD (superoxide dismutase), APX (ascorbate peroxidase) and GPX (guaiacol peroxidase) resulting in reduced lipid peroxidation in S. arundinaceum. AMF symbiosis also ameliorated the drought-induced reduction of total chlorophyll content and activities of photosystem I and II. The maximum quantum efficiency of PS II (F v/F m) and potential photochemical efficiency (F v/F o) were higher in AMF plants as compared to non-AMF plants under drought stress. These results indicate that AMF association alleviate drought stress in S. arundinaceum by the accumulation of osmolytes and non-enzymatic antioxidants and enhanced activities of antioxidant enzymes, and hence, the photosynthetic efficiency is improved resulting in increased biomass production. AMF association with energy grasses also improves the acclimatization of S. arundinaceum for growing in marginal lands of drought-affected soils. PMID:27329476

  9. Infectivity of Arbuscular Mycorrhizal Fungi in Naturally Regenerating, Unmanaged and Clear-Cut Beech Forests

    Institute of Scientific and Technical Information of China (English)

    I.CLOSA; N.GOICOECHEA

    2011-01-01

    Clear-cutting, a management practice applied to many beech forests in the North of Spain, modifies microclimate and, consequently,the composition of the understory plant community in the disturbed areas. The objectives of this study were to assess if changes in the understory vegetation caused by altered light microclimate after clear-cutting affect the infectivity of arbuscular mycorrhizal fungi (AMF) on herbaceous plant species in beech (Fagus sylvatica L.) forests naturally regenerating from clear-cutting and to test if the use of bioassays for studying the infectivity of native AMF could provide aseful information to improve the management of clear-cut areas.Three nearby beech forests in northwest Navarra, Spain, a region in the northwest part of the Pyrenees, were selected: an unmanaged forest, a forest clear-cut in 1996, and another forest clear-cut in 2001. High stem density in the forest clear-cut in 1996 (44 000 trees ha-1) attenuated photosynthetic active radiation (PAR) and impaired the growth of herbaceous species within the ecosystem. The percentage of AMF colonization of plants in bioassays performed on soil samples collected from the forest clear-cut in 1996 was always lower than 10%. In the forest clear-cut in 2001, where soil was covered by perennial grasses, PAR was high and thc infectivity of native AMF achieved minimum values in spring and autumn and a maximum value in summer. In contrast, the infectivity of native AMF in the umnanaged forest remained similar across the seasons. Our results demonstrated that changes in the composition of understory vegetation within beech forests strongly affected the infectivity of native AMF in clear-cut areas and suggested that the assessment of the infectivity of native AMF through bioassays could provide helpful information for planning either the removal of overstory when the tree density is so high that it impairs the correct development of herbaceous species or the plantation of new sesdlings when high

  10. Mycorrhizal colonization and diversity and corn genotype yield in soils of the Cerrado region, Brazil

    Directory of Open Access Journals (Sweden)

    Sueli da Silva Aquino

    2015-12-01

    Full Text Available The degree of interaction between arbuscular mycorrhizal fungi (AMF and host plants appears to depend on plant genotype, which differentially promotes symbiosis and leads to different degree of mycotrophism. The aim of the present study was to assess root colonization, spore density, and diversity of AMF, as well as yield of corn (Zea mays genotypes in soil from the Cerrado region of Brazil. Number of spores (NS, mycorrhizal colonization (COL, plant and ear height, dry weight (DW, and grain yield (GY were assessed in inbred lines and their hybrids. Randomized blocks were used for the experimental design, with 30 treatments (genotypes and three repetitions. The experiment was conducted on the farm of the UNESP-São Paulo State University, Campus of Ilha Solteira, and the plots were composed of two 2-m-long rows, with 0.85 m between rows, and 0.20 m between plants. Qualitative and quantitative changes were observed in fungal compositions, as well as preferential associations between symbiotic partners. Analysis of AMF diversity revealed the presence of 12 species, with Scutellospora calospora and Entrophospora colombiana being the most abundant in all treatments. The species Acaulospora longula, Glomus etunicatum, Glomus macrocarpum, and Gigaspora margarita exhibited preferential associations with certain genotypes. COL and GY differed among inbred lines and single-cross hybrids and the significant correlations between COL and the DW and GY showed positive interactions between the plants and AMF. There was no correlation between heterosis for GY and heterosis for colonization. These single-cross hybrids HS83 × E3 and D3 × F5 exhibited high GY, evidencing a productivity potential for the low technological condition used.

  11. Application ofArbuscular Mycorrhizal Inocula Might Be A Promising Method in the Restoration of Severely Degraded Wetlands%Application of Arbuscular Mycorrhizal Inocula Might Be A Promising Method in the Restoration of Severely Degraded Wetlands

    Institute of Scientific and Technical Information of China (English)

    De Gao

    2013-01-01

    The application of arbuscular mycorrhizal (AM) inocula in severely degraded wetlands could ensure success in restoration.Mycorrhizal fungi play an important role in plant individual' s survival and development in a low nutrient condition.Based on the importance that mycorrhizal fungi have to their host plants,mycorrhizal inocula have been produced and applied in terrestrial ecosystems in order to let the plants become mycorrhizal.However,mycorrhizal inocula have not been used in wetland restorations,despite increasing evidence that mycorrhizal fungi are commonly found in various wetland systems and have the ability to survive under anoxic conditions.Evidence also shows that mycorrhizal fungal inocula in the soil could have been destroyed in the degraded wetland or could be destroyed during traditional wetland restoration process.Therefore,AM inocula production is strongly recommended for wetland restoration.In this paper,I will argue that AM inocula production is required when introduced recovery is necessary,and aeroponic culture technique is a preferable method to produce AM inocula.Last,a renewed wetland restoration flow chart is summarized.

  12. Carbon availability triggers fungal nitrogen uptake and transport in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Fellbaum, Carl R; Gachomo, Emma W; Beesetty, Yugandhar; Choudhari, Sulbha; Strahan, Gary D; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2012-02-14

    The arbuscular mycorrhizal (AM) symbiosis, formed between the majority of land plants and ubiquitous soil fungi of the phylum Glomeromycota, is responsible for massive nutrient transfer and global carbon sequestration. AM fungi take up nutrients from the soil and exchange them against photosynthetically fixed carbon (C) from the host. Recent studies have demonstrated that reciprocal reward strategies by plant and fungal partners guarantee a "fair trade" of phosphorus against C between partners [Kiers ET, et al. (2011) Science 333:880-882], but whether a similar reward mechanism also controls nitrogen (N) flux in the AM symbiosis is not known. Using mycorrhizal root organ cultures, we manipulated the C supply to the host and fungus and followed the uptake and transport of N sources in the AM symbiosis, the enzymatic activities of arginase and urease, and fungal gene expression in the extraradical and intraradical mycelium. We found that the C supply of the host plant triggers the uptake and transport of N in the symbiosis, and that the increase in N transport is orchestrated by changes in fungal gene expression. N transport in the symbiosis is stimulated only when the C is delivered by the host across the mycorrhizal interface, not when C is supplied directly to the fungal extraradical mycelium in the form of acetate. These findings support the importance of C flux from the root to the fungus as a key trigger for N uptake and transport and provide insight into the N transport regulation in the AM symbiosis.

  13. [Change of arbuscular mycorrhizal fungi community in response to elevational gradients on the Tibetan Plateau, China].

    Science.gov (United States)

    Cai, Xiao-bu; Peng, Yue-lin

    2015-09-01

    The community structure of arbuscular mycorrhizal fungi (AMF) and mycorrhizal infection in the main herbaceous plants were studied along the elevational gradients on the Tibetan Plateau, and AMF community was characterized based on spore morphology. Community of AMF at lower elevations (2200-3400 m) in southeast Tibetan Plateau included 11 genera, covering 31 species, whereas AMF at intermediate elevations (3400-3900 m) in central Tibet included 11 genera, covering 20 species, and that at higher elevations (4300-5300 m) in northern Tibet included 6 genera, covering 14 species. With the increase of elevation, both spore density (r = 0.978, P 0.05) tended to increase. The proportion of dominant species and endemic species increased substantially, while the Shannon index (r = -0.945, P AMF community and mycorrhizal infection, and the effect differed among the three elevational sites. The results demonstrated that AMF community on the Tibetan Plateau tends to be habitat specific. The water and thermal environment as well as soil environment are the driving forces for shaping AMF community assemblages. PMID:26785564

  14. Reduced germination of Orobanche cumana seeds in the presence of Arbuscular Mycorrhizal fungi or their exudates.

    Science.gov (United States)

    Louarn, Johann; Carbonne, Francis; Delavault, Philippe; Bécard, Guillaume; Rochange, Soizic

    2012-01-01

    Broomrapes (Orobanche and Phelipanche spp) are parasitic plants responsible for important crop losses, and efficient procedures to control these pests are scarce. Biological control is one of the possible strategies to tackle these pests. Arbuscular Mycorrhizal (AM) fungi are widespread soil microorganisms that live symbiotically with the roots of most plant species, and they have already been tested on sorghum for their ability to reduce infestation by witchweeds, another kind of parasitic plants. In this work AM fungi were evaluated as potential biocontrol agents against Orobanche cumana, a broomrape species that specifically attacks sunflower. When inoculated simultaneously with O. cumana seeds, AM fungi could offer a moderate level of protection against the broomrape. Interestingly, this protection did not only rely on a reduced production of parasitic seed germination stimulants, as was proposed in previous studies. Rather, mycorrhizal root exudates had a negative impact on the germination of O. cumana induced by germination stimulants. A similar effect could be obtained with AM spore exudates, establishing the fungal origin of at least part of the active compounds. Together, our results demonstrate that AM fungi themselves can lead to a reduced rate of parasitic seed germination, in addition to possible effects mediated by the mycorrhizal plant. Combined with the other benefits of AM symbiosis, these effects make AM fungi an attractive option for biological control of O. cumana. PMID:23145139

  15. Arginine bi-directional translocation and breakdown into ornithine along the arbuscular mycorrhizal mycelium

    Institute of Scientific and Technical Information of China (English)

    JIN HaiRu

    2009-01-01

    Bi-directional translocatlon and degradation of Arginine (Arg) along the arbuscular mycorrhizal (AM) fungal mycellum were testified through 15N and/or 13C isotopic labeling. In vitro mycorrhizas of Glomus intraradices and Ri T-DNA-transformed carrot roots were grown in dual compartment Petri dishes. [15N-and/or13C]Arg was supplied to either the fungal compartment or the mycorrhizal compartment or separate dishes containing the uncolonized roots. The levels and labeling of free amino acids (AAs) in the mycorrhizal roots and in the extraradical mycelia(ERM) were measured by gas chromatogra-phy/mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The ERM of AM fungi exposed in either NH4+ or urea as sole external nitrogen source had much higher 15N enrichment of Arg, compared with those In nitrate or exogenous Arg; however, glycerol supplied as an external car-bon source to the ERM had no significant effect on the level of Arg in the ERM. Meanwhile, Arg bio-synthesized In the ERM could be translocated intact to the mycorrhizal roots and thereby the level of Arg in the mycorrhizal roots increased to about 20% after culture of ERM in 4 mmol/L NH4+ for 6 weeks.Also Arg was found to be bi-directionally transported along the AM fungal mycelium through [U-13C]Arg labeling either In the mycorrhizal compartment or in the fungal compartment. Once Arg was translo-cated to the potential N-limited sites, it would be further degraded into ornithine (Orn) and urea since either [U-13C] or [U-15N/U-13C]Orn was apparently shown up in the mycorrhizal root tissues when [U-13C] or [U-15N/U-13C]Arg was labeled In the fungal compartment, respectively. Evidently Orn formation indi-cated the ongoing activities of Arg translocation and degradation through the urea cycle in AM fungal mycelium.

  16. Arginine bi-directional translocation and breakdown into ornithine along the arbuscular mycorrhizal mycelium

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Bi-directional translocation and degradation of Arginine (Arg) along the arbuscular mycorrhizal (AM) fungal mycelium were testified through 15N and/or 13C isotopic labeling. In vitro mycorrhizas of Glomus intraradices and Ri T-DNA-transformed carrot roots were grown in dual compartment Petri dishes. [15N- and/or13C]Arg was supplied to either the fungal compartment or the mycorrhizal compartment or separate dishes containing the uncolonized roots. The levels and labeling of free amino acids (AAs) in the mycorrhizal roots and in the extraradical mycelia(ERM) were measured by gas chromatogra- phy/mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The ERM of AM fungi exposed in either NH4+ or urea as sole external nitrogen source had much higher 15N enrichment of Arg, compared with those in nitrate or exogenous Arg; however, glycerol supplied as an external car- bon source to the ERM had no significant effect on the level of Arg in the ERM. Meanwhile, Arg bio- synthesized in the ERM could be translocated intact to the mycorrhizal roots and thereby the level of Arg in the mycorrhizal roots increased to about 20% after culture of ERM in 4 mmol/L NH4+ for 6 weeks. Also Arg was found to be bi-directionally transported along the AM fungal mycelium through [U-13C]Arg labeling either in the mycorrhizal compartment or in the fungal compartment. Once Arg was translo- cated to the potential N-limited sites, it would be further degraded into ornithine (Orn) and urea since either [U-13C] or [U-15N/U-13C]Orn was apparently shown up in the mycorrhizal root tissues when [U-13C] or [U-15N/U-13C]Arg was labeled in the fungal compartment, respectively. Evidently Orn formation indi- cated the ongoing activities of Arg translocation and degradation through the urea cycle in AM fungal mycelium.

  17. Isolated root caps, border cells, and mucilage from host roots stimulate hyphal branching of the arbuscular mycorrhizal fungus, Gigaspora gigantea.

    Science.gov (United States)

    Nagahashi, Gerald; Douds, David D

    2004-09-01

    Unlike previous reports that have shown that water soluble and volatile compounds from roots or root exudates play an important role in precolonization events during arbuscular mycorrhizal (AM) fungus-host root interactions (Bécard & Piché 1989, Giovannetti et al. 1993), the results shown here deal with particulate and viscous fractions isolated from host roots. Root caps and a slow sedimenting particulate fraction (SSPF) were rapidly isolated and separated from Ri T-DNA transformed carrot roots (D. carota) grown in liquid culture. In addition, border cells (BC) and mucilage were isolated from aseptically grown corn seedlings (Zea mays). Root caps, SSPF (composed mainly of small root cap fragments and some BCs), BCs, and mucilage all had an associated AM fungus hyphal branching stimulator. Root caps stored for 5 d at 4 degrees C appeared to either synthesize or slowly release the branching stimulator. Also, isolated root caps from roots grown in the absence of P contained more branch stimulating activity than those isolated from roots grown in the presence of P. Although the branching stimulation activity in particulate fractions was low compared to that of the exudate, the particulate fractions can stick to the root surface at considerable distances from the root tip. This may be significant during the infection and colonization of host roots at sites far removed from the primary location of exudation.

  18. Land-use intensity and host plant identity interactively shape communities of arbuscular mycorrhizal fungi in roots of grassland plants.

    Science.gov (United States)

    Vályi, Kriszta; Rillig, Matthias C; Hempel, Stefan

    2015-03-01

    We studied the effect of host plant identity and land-use intensity (LUI) on arbuscular mycorrhizal fungi (AMF, Glomeromycota) communities in roots of grassland plants. These are relevant factors for intraradical AMF communities in temperate grasslands, which are habitats where AMF are present in high abundance and diversity. In order to focus on fungi that directly interact with the plant at the time, we investigated root-colonizing communities. Our study sites represent an LUI gradient with different combinations of grazing, mowing, and fertilization. We used massively parallel multitag pyrosequencing to investigate AMF communities in a large number of root samples, while being able to track the identity of the host. We showed that host plants significantly differed in AMF community composition, while land use modified this effect in a plant species-specific manner. Communities in medium and low land-use sites were subsets of high land-use communities, suggesting a differential effect of land use on the dispersal of AMF species with different abundances and competitive abilities. We demonstrate that in these grasslands, there is a small group of highly abundant, generalist fungi which represent the dominating species in the AMF community.

  19. Two putative-aquaporin genes are differentially expressed during arbuscular mycorrhizal symbiosis in Lotus japonicus

    Directory of Open Access Journals (Sweden)

    Giovannetti Marco

    2012-10-01

    Full Text Available Abstract Background Arbuscular mycorrhizas (AM are widespread symbioses that provide great advantages to the plant, improving its nutritional status and allowing the fungus to complete its life cycle. Nevertheless, molecular mechanisms that lead to the development of AM symbiosis are not yet fully deciphered. Here, we have focused on two putative aquaporin genes, LjNIP1 and LjXIP1, which resulted to be upregulated in a transcriptomic analysis performed on mycorrhizal roots of Lotus japonicus. Results A phylogenetic analysis has shown that the two putative aquaporins belong to different functional families: NIPs and XIPs. Transcriptomic experiments have shown the independence of their expression from their nutritional status but also a close correlation with mycorrhizal and rhizobial interaction. Further transcript quantification has revealed a good correlation between the expression of one of them, LjNIP1, and LjPT4, the phosphate transporter which is considered a marker gene for mycorrhizal functionality. By using laser microdissection, we have demonstrated that one of the two genes, LjNIP1, is expressed exclusively in arbuscule-containing cells. LjNIP1, in agreement with its putative role as an aquaporin, is capable of transferring water when expressed in yeast protoplasts. Confocal analysis have demonstrated that eGFP-LjNIP1, under its endogenous promoter, accumulates in the inner membrane system of arbusculated cells. Conclusions Overall, the results have shown different functionality and expression specificity of two mycorrhiza-inducible aquaporins in L. japonicus. One of them, LjNIP1 can be considered a novel molecular marker of mycorrhizal status at different developmental stages of the arbuscule. At the same time, LjXIP1 results to be the first XIP family aquaporin to be transcriptionally regulated during symbiosis.

  20. Enhanced production of steviol glycosides in mycorrhizal plants: a concerted effect of arbuscular mycorrhizal symbiosis on transcription of biosynthetic genes.

    Science.gov (United States)

    Mandal, Shantanu; Upadhyay, Shivangi; Singh, Ved Pal; Kapoor, Rupam

    2015-04-01

    Stevia rebaudiana (Bertoni) produces steviol glycosides (SGs)--stevioside (stev) and rebaudioside-A (reb-A) that are valued as low calorie sweeteners. Inoculation with arbuscular mycorrhizal fungi (AMF) augments SGs production, though the effect of this interaction on SGs biosynthesis has not been studied at molecular level. In this study transcription profiles of eleven key genes grouped under three stages of the SGs biosynthesis pathway were compared. The transcript analysis showed upregulation of genes encoding 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway enzymes viz.,1-deoxy-D-xylulose 5-phospate synthase (DXS), 1-deoxy-D-xylulose 5-phospate reductoisomerase (DXR) and 2-C-methyl-D-erytrithol 2,4-cyclodiphosphate synthase (MDS) in mycorrhizal (M) plants. Zn and Mn are imperative for the expression of MDS and their enhanced uptake in M plants could be responsible for the increased transcription of MDS. Furthermore, in the second stage of SGs biosynthesis pathway, mycorrhization enhanced the transcription of copalyl diphosphate synthase (CPPS) and kaurenoic acid hydroxylase (KAH). Their expression is decisive for SGs biosynthesis as CPPS regulates flow of metabolites towards synthesis of kaurenoid precursors and KAH directs these towards steviol synthesis instead of gibberellins. In the third stage glucosylation of steviol to reb-A by four specific uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs) occurs. While higher transcription of all the three characterized UGTs in M plants explains augmented production of SGs; higher transcript levels of UGT76G1, specifically improved reb-A to stev ratio implying increased sweetness. The work signifies that AM symbiosis upregulates the transcription of all eleven SGs biosynthesis genes as a result of improved nutrition and enhanced sugar concentration due to increased photosynthesis in M plants. PMID:25734328

  1. 荒漠北沙柳根系丛枝菌根真菌和黑隔内生真菌定殖状况%Colonization of arbuscular mycorrhizal fungi and dark septate endophytes in roots of desert Salix psammophila

    Institute of Scientific and Technical Information of China (English)

    闫姣; 贺学礼; 张亚娟; 许伟; 张娟; 赵丽莉

    2014-01-01

    为利用土壤共生真菌资源促进荒漠植被恢复和生态重建,分别于2013年6月、8月和10月,从内蒙古元上都地区采集北沙柳(Salix psammophila)根围0-10、10-20、20-30、30-40和40-50 cm共5个土层的土壤样品,系统研究了丛枝菌根真菌(AMF)和黑隔内生真菌(DSE)的时空分布及其与土壤因子的相关性。结果表明:AMF和DSE的平均定殖率分别为77%和84%,说明北沙柳根系能与这两类真菌形成良好的共生关系。AMF和DSE的分布和定殖具有明显的时空异质性,并与土壤因子密切相关。AMF和DSE的平均定殖率均表现为10月>8月>6月。土壤深度对AMF和DSE的定殖率有显著影响, AMF和DSE定殖率的最大值分别在0-20 cm和0-10 cm土层。双因子方差分析表明,月份和土层对AMF和DSE的定殖率以及土壤因子具有显著的交互效应。主成分分析表明,土壤湿度、pH值、碱性磷酸酶、易提取球囊霉素是内蒙古荒漠环境中AMF和DSE定殖的主要影响因子。%Aims Salix psammophila is an excellent shrub for afforestation and sand dune fixation and is mainly distributes in the arid zones in North China. The objective of this study was to determine the colonization of arbuscular my-corrhizal fungi (AMF) and dark septate endophytes (DSE), and the relationships among AMF, DSE and soil fac-tors in the rhizosphere of S. psammophila, in order to provide information guiding the recovery of desert vegeta-tion and ecological reconstruction. Methods Soil and root samples were collected from different soil layers (0-10, 10-20, 20-30, 30-40 and 40-50 cm) in the rhizosphere of S. psammophila in June, August and October 2013 at Yuan Shangdu in Nei Mongol. The colonization and distribution of AMF and DSE were assessed, and the relationships among AMF, DSE and soil factors were determined and tested by variance analysis, correlation analysis and principal com-ponent analysis. Important findings The roots of S

  2. Symbiotic efficiency of autochthonous arbuscular mycorrhizal fungus (G. mosseae) and Brevibacillus sp. isolated from cadmium polluted soil under increasing cadmium levels

    Energy Technology Data Exchange (ETDEWEB)

    Vivas, A.; Voeroes, I.; Biro, B.; Campos, E.; Barea, J.M.; Azcon, R

    2003-11-01

    Selected ubiquitous microorganisms are important components of Cd tolerance in plants. - The effect of inoculation with indigenous naturally occurring microorganisms [an arbuscular mycorrhizal (AM) fungus and rhizosphere bacteria] isolated from a Cd polluted soil was assayed on Trifolium repens growing in soil contaminated with a range of Cd. One of the bacterial isolate showed a marked PGPR effect and was identified as a Brevibacillus sp. Mycorrhizal colonization also enhanced Trifolium growth and N, P, Zn and Ni content and the dually inoculated (AM fungus plus Brevibacillus sp.) plants achieved further growth and nutrition and less Cd concentration, particularly at the highest Cd level. Increasing Cd level in the soil decreased Zn and Pb shoot accumulation. Coinoculation of Brevibacillus sp. and AM fungus increased shoot biomass over single mycorrhizal plants by 18% (at 13.6 mg Cd kg{sup -1}), 26% (at 33.0 mg Cd kg{sup -1}) and 35% (at 85.1 mg Cd kg{sup -1}). In contract, Cd transfer from soil to plants was substantially reduced and at the highest Cd level Brevibacillus sp. lowered this value by 37.5% in AM plants. Increasing Cd level highly reduced plant mycorrhization and nodulation. Strong positive effect of the bacterium on nodule formation was observed in all treatments. Results show that selected ubiquitous microorganisms, applied as enriched inocula, are important in plant Cd tolerance and development in Cd polluted soils.

  3. Arbuscular Mycorrhizal (AM) Diversity in Prosopis cineraria (L.) Druce Under Arid Agroecosystems

    Institute of Scientific and Technical Information of China (English)

    Neelam Verma; Jagadish Chandra Tarafdar; Krishna Kant Srivastava; Jitendra Panwar

    2008-01-01

    Arbuscular mycorrhizal (AM) fungi associated with Prosopis cineraria (Khejri) were assessed for their qualitative and quantitative distribution from eight districts of Rajasthan. A total of three species of Acaulospora, one species of Entrophospora, two species of Gigaspora, twenty-one species of Glomus, seven species of Sclerocystis and three species of Scutellospora were recorded. A high diversity of AM fungi was observed and it varied at different study sites. Among these six genera, Glomus occurred most frequently. Glomus fasciculatum, Glomus aggregatum, and Glomus mosseae were found to be the most predominant AM fungi in infecting Prosopis cineraria. Acaulospora, G. fasciculatum, Sclerocystis was found in all the fields studied, while Scutellospora species were found only in few sites. A maximum of thirty-six AM fungal species were isolated and identified from Jodhpur, whereas only thirteen species were found from Jaisalmer. Spores of Glomus fasciculatum were found to be most abundant under Prosopis cineraria.

  4. Detection and characterization of mycoviruses in arbuscular mycorrhizal fungi by deep-sequencing.

    Science.gov (United States)

    Ezawa, Tatsuhiro; Ikeda, Yoji; Shimura, Hanako; Masuta, Chikara

    2015-01-01

    Fungal viruses (mycoviruses) often have a significant impact not only on phenotypic expression of the host fungus but also on higher order biological interactions, e.g., conferring plant stress tolerance via an endophytic host fungus. Arbuscular mycorrhizal (AM) fungi in the phylum Glomeromycota associate with most land plants and supply mineral nutrients to the host plants. So far, little information about mycoviruses has been obtained in the fungi due to their obligate biotrophic nature. Here we provide a technical breakthrough, "two-step strategy" in combination with deep-sequencing, for virological study in AM fungi; dsRNA is first extracted and sequenced using material obtained from highly productive open pot culture, and then the presence of viruses is verified using pure material produced in the in vitro monoxenic culture. This approach enabled us to demonstrate the presence of several viruses for the first time from a glomeromycotan fungus.

  5. Glomus claroideum and G. spurcum, arbuscular mycorrhizal fungi (Glomeromycota new for Poland and Europe, respectively

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2011-04-01

    Full Text Available The ontogenetic development and morphological properties of spores of two species of arbuscular mycorrhizal fungi (Glomeromycota of the genus Glomus, G. claroideum and G. spurcum, are described and illustrated. Spores of the two species were not earlier found in Poland, and this paper is the first report of the occurrence of G. spurcum in Europe. In one-species pot cultures with Plantago lanceolata as the host plant, the mycorrhizae of G. claroideum consist of arbuscules, vesicles, as well as intra- and extraradical hyphae staining intensively with trypan blue. Glomus spurcum mycorrhizae were not recognized, because many attempts to establish one-species cultures of this fungus failed. Additionally, the distribution of both the fungi in the world is presented.

  6. Options of partners improve carbon for phosphorus trade in the arbuscular mycorrhizal mutualism.

    Science.gov (United States)

    Argüello, Alicia; O'Brien, Michael J; van der Heijden, Marcel G A; Wiemken, Andres; Schmid, Bernhard; Niklaus, Pascal A

    2016-06-01

    The mutualism between plants and arbuscular mycorrhizal fungi (AMF) is widespread and has persisted for over 400 million years. Although this mutualism depends on fair resource exchange between plants and fungi, inequality exists among partners despite mechanisms that regulate trade. Here, we use (33) P and (14) C isotopes and a split-root system to test for preferential allocation and reciprocal rewards in the plant-AMF symbiosis by presenting a plant with two AMF that differ in cooperativeness. We found that plants received more (33) P from less cooperative AMF in the presence of another AMF species. This increase in (33) P resulted in a reduced (14) C cost per unit of (33) P from less cooperative AMF when alternative options were available. Our results indicate that AMF diversity promotes cooperation between plants and AMF, which may be an important mechanism maintaining the evolutionary persistence of and diversity within the plant-AMF mutualism. PMID:27074533

  7. Genetic structure of arbuscular mycorrhizal populations in fallow and cultivated soils

    DEFF Research Database (Denmark)

    Rosendahl, Søren; Matzen, Hans

    2008-01-01

    •  The impact of fallowing on the genetic structure of arbuscular mycorrhizal fungi (AMF) was studied by hierarchical sampling of spores from four plots in a fallow and a cultivated field. •  A nested multiplex PCR approach was used to assign the spores to genotypes. Variable introns of the two...... be attributed to variation between plots rather than subplots, suggesting that the lack of soil cultivation resulted in more heterogeneous population genetic structures. Analyses of haplotype networks of the fungi suggested a subdivision of G. mosseae haplotypes between the two fields, whereas no such division...... was seen in G. geosporum and G. caledonium. The results show that agricultural practices differently affect both the abundance and the population structure of different AMF species....

  8. DNA-Based Characterization and Identification of Arbuscular Mycorrhizal Fungi Species.

    Science.gov (United States)

    Senés-Guerrero, Carolina; Schüßler, Arthur

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate symbionts of most land plants. They have great ecological and economic importance as they can improve plant nutrition, plant water supply, soil structure, and plant resistance to pathogens. We describe two approaches for the DNA-based characterization and identification of AMF, which both can be used for single fungal spores, soil, or roots samples and resolve closely related AMF species: (a) Sanger sequencing of a 1.5 kb extended rDNA-barcode from clone libraries, e.g., to characterize AMF isolates, and (b) high throughput 454 GS-FLX+ pyrosequencing of a 0.8 kb rDNA fragment, e.g., for in-field monitoring. PMID:26791499

  9. A critical review on the nutrition role of arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Omid Alizadeh

    2012-06-01

    Full Text Available Even though many factors influence the accession of mineral nutrients required for plantgrowth, arbuscular mycorrhizal-roots can greatly enhance the accession of mineral nutrients in hostplants. The nutrients enhanced most by AM are those that are of low mobility or sparingly soluble. Withother factors being equal in specific environments, AM may be the difference between whether plants willsurvive and/or have the ability to obtain the required mineral nutrients for sustainability. Although themost commonly reported mineral nutrient enhanced in host plants with AM-roots is P, accession of manyother mineral nutrients (e.g., Zn, Cu, N, S, Ca, Mg, K may be enhanced in plants by AM. Severalreviews about accession of mineral nutrients in AM plants have been published fairly recently. Some ofthe concepts mentioned with P accession may be applicable to the other mineral nutrients. This reviewgives an overview on the role of mycorrhizae in nutrition.

  10. Carbon and nitrogen metabolism in arbuscular mycorrhizal maize plants under low-temperature stress

    DEFF Research Database (Denmark)

    Zhu, Xian-Can; Song, Feng-Bin; Liu, Fulai;

    2015-01-01

    Effects of the arbuscular mycorrhizal (AM) fungus Glomus tortuosum on carbon (C) and nitrogen (N) metabolism of Zea mays L. grown under low-temperature stress was investigated. Maize plants inoculated or not inoculated with AM fungus were grown in a growth chamber at 258C for 4 weeks...... and subsequently subjected to two temperature treatments (158C, low temperature; 258C, ambient control) for 2 weeks. Low-temperature stress significantly decreasedAMcolonisation, plant height and biomass. TotalNcontent and activities of glutamate oxaloacetate transaminase and glutamate pyruvate transaminase of AM...... plants were higher than those of non-AM plants. AM plants had a higher net photosynthetic rate (Pn) than non-AM plants, although low temperature inhibited the Pn. Compared with non-AM plants, AM plants exhibited higher leaf soluble sugars, reducing sugars, root sucrose and fructose contents, and sucrose...

  11. [Effects of arbuscular mycorrhizal fungi on root system morphology and sucrose and glucose contents of Poncirus trifoliata].

    Science.gov (United States)

    Zou, Ying-Ning; Wu, Qiang-Sheng; Li, Yan; Huang, Yong-Ming

    2014-04-01

    The effects of inoculation with Glomus mosseae, G. versiforme, and their mixture on plant growth, root system morphology, and sucrose and glucose contents of trifoliate orange (Poncirus trifoliata L.) were studied by pot culture. The results showed that all the inoculated treatments significantly increased the plant height, stem diameter, leaf number, and shoot and root biomass. In addition, the mycorrhizal treatments significantly increased the number of 1st, 2nd, and 3rd lateral roots. Inoculation with arbuscular mycorrhizal fungi significantly increased the root projected area, surface area, volume, and total root length (mainly 0-1 cm root length), but decreased the root average diameter. Meanwhile, G. versiforme showed the best effects. Mycorrhizal inoculation significantly increased the leaf sucrose and root glucose contents, but decreased the leaf glucose and root sucrose contents. Owing to the 'mycorrhizal carbon pool' in roots, inoculation with arbuscular mycorrhizal fungi resulted in high glucose content and low sucrose content of roots, which would facilitate the root growth and development, thereby the establishment of better root system morphology of host plants.

  12. Effect of plant species, soil and environmental factors on vesicular-arbuscular mycorrhizal (VAM) infection and nutrient uptake

    International Nuclear Information System (INIS)

    The vesicular-arbuscular mycorrhizal (VAM) system should meaningfully be considered as a 3-way interaction between plant, soil and fungus. By disassembling the complex VA mycorrhizal symbiosis and considering each component in turn, it has become evident that many factors, such as plant species, soil and environmental conditions can affect the overall balance of the complete system. For the plant to gain maximum benefits from the association, the best possible contribution of plant, fungus and environmental conditions need to be identified and maintained. (author)

  13. Diversity and spatial structure of belowground plant-fungal symbiosis in a mixed subtropical forest of ectomycorrhizal and arbuscular mycorrhizal plants.

    Directory of Open Access Journals (Sweden)

    Hirokazu Toju

    Full Text Available Plant-mycorrhizal fungal interactions are ubiquitous in forest ecosystems. While ectomycorrhizal plants and their fungi generally dominate temperate forests, arbuscular mycorrhizal symbiosis is common in the tropics. In subtropical regions, however, ectomycorrhizal and arbuscular mycorrhizal plants co-occur at comparable abundances in single forests, presumably generating complex community structures of root-associated fungi. To reveal root-associated fungal community structure in a mixed forest of ectomycorrhizal and arbuscular mycorrhizal plants, we conducted a massively-parallel pyrosequencing analysis, targeting fungi in the roots of 36 plant species that co-occur in a subtropical forest. In total, 580 fungal operational taxonomic units were detected, of which 132 and 58 were probably ectomycorrhizal and arbuscular mycorrhizal, respectively. As expected, the composition of fungal symbionts differed between fagaceous (ectomycorrhizal and non-fagaceous (possibly arbuscular mycorrhizal plants. However, non-fagaceous plants were associated with not only arbuscular mycorrhizal fungi but also several clades of ectomycorrhizal (e.g., Russula and root-endophytic ascomycete fungi. Many of the ectomycorrhizal and root-endophytic fungi were detected from both fagaceous and non-fagaceous plants in the community. Interestingly, ectomycorrhizal and arbuscular mycorrhizal fungi were concurrently detected from tiny root fragments of non-fagaceous plants. The plant-fungal associations in the forest were spatially structured, and non-fagaceous plant roots hosted ectomycorrhizal fungi more often in the proximity of ectomycorrhizal plant roots. Overall, this study suggests that belowground plant-fungal symbiosis in subtropical forests is complex in that it includes "non-typical" plant-fungal combinations (e.g., ectomycorrhizal fungi on possibly arbuscular mycorrhizal plants that do not fall within the conventional classification of mycorrhizal symbioses, and in

  14. Diversity and spatial structure of belowground plant-fungal symbiosis in a mixed subtropical forest of ectomycorrhizal and arbuscular mycorrhizal plants.

    Science.gov (United States)

    Toju, Hirokazu; Sato, Hirotoshi; Tanabe, Akifumi S

    2014-01-01

    Plant-mycorrhizal fungal interactions are ubiquitous in forest ecosystems. While ectomycorrhizal plants and their fungi generally dominate temperate forests, arbuscular mycorrhizal symbiosis is common in the tropics. In subtropical regions, however, ectomycorrhizal and arbuscular mycorrhizal plants co-occur at comparable abundances in single forests, presumably generating complex community structures of root-associated fungi. To reveal root-associated fungal community structure in a mixed forest of ectomycorrhizal and arbuscular mycorrhizal plants, we conducted a massively-parallel pyrosequencing analysis, targeting fungi in the roots of 36 plant species that co-occur in a subtropical forest. In total, 580 fungal operational taxonomic units were detected, of which 132 and 58 were probably ectomycorrhizal and arbuscular mycorrhizal, respectively. As expected, the composition of fungal symbionts differed between fagaceous (ectomycorrhizal) and non-fagaceous (possibly arbuscular mycorrhizal) plants. However, non-fagaceous plants were associated with not only arbuscular mycorrhizal fungi but also several clades of ectomycorrhizal (e.g., Russula) and root-endophytic ascomycete fungi. Many of the ectomycorrhizal and root-endophytic fungi were detected from both fagaceous and non-fagaceous plants in the community. Interestingly, ectomycorrhizal and arbuscular mycorrhizal fungi were concurrently detected from tiny root fragments of non-fagaceous plants. The plant-fungal associations in the forest were spatially structured, and non-fagaceous plant roots hosted ectomycorrhizal fungi more often in the proximity of ectomycorrhizal plant roots. Overall, this study suggests that belowground plant-fungal symbiosis in subtropical forests is complex in that it includes "non-typical" plant-fungal combinations (e.g., ectomycorrhizal fungi on possibly arbuscular mycorrhizal plants) that do not fall within the conventional classification of mycorrhizal symbioses, and in that

  15. Arbuscular mycorrhizal formation of crucifer leaf mustard induced by flavonoids apigenin and daidzein

    Institute of Scientific and Technical Information of China (English)

    DONG Changjin; ZHAO Bin

    2004-01-01

    Flavonoids from legume root secretion may probably act as signal molecules for expression of Rhizobial "nod" nodulation genes and AM fungal symbiotic gene. Leaf mustard is a non-mycorrhizal plant; it does not contain fiavonoids and other signal molecules. AM fungi could not infect the roots of leaf mustard and form a symbiont in nature,when it was treated with fiavonoids (apigenin or daidzein).The results of trypan blue staining showed that two kinds of AM fungi (G. intraradices and G mosseae) successfully infected the roots of non-mycorrhizal plant leaf mustard. AM fungi grew towards and colonized the roots of leaf mustard,producing young spores and completing the course of life.AM fungi are the only one kind of fungi with ALP activity.The result of ALP staining has also proved that AM fungi infected successfully the roots of leaf mustard. AM fungi (G.intraradices and G. mosseae) that existed in the roots of non-mycorrhizal plant leaf mustard were probed by nested PCR and special molecular probes. The above-mentioned proof chains have fully proved that fiavonoids induced AM fungi (G. intraradices and G mosseae) to infect non-mycorrhizal plant and establish symbiotic relationship.

  16. [Arbuscular mycorrhizal bioremediation and its mechanisms of organic pollutants-contaminated soils].

    Science.gov (United States)

    Li, Qiuling; Ling, Wanting; Gao, Yanzheng; Li, Fuchun; Xiong, Wei

    2006-11-01

    Arbuscular mycorrhiza (AM), the symbiont of arbuscular mycorrhizal fungi (AMF) and host plant root, has been proved to be able to improve soil structure and enhance the plant resistance to environmental stress. There are more than 170 kinds of AMF worldwide. Recently, the promoted degradation of organic pollutants in soils in the presence of AM was observed, and AM bioremediation (AMB) is becoming a promising and perspective remediation technique for organic pollutants-contaminated soils. This paper reviewed the research progress on the AMB of soils contaminated by typical organic pollutants such as polycyclic aromatic hydrocarbons, PAEs, petroleum, and pesticides. The mechanisms of AMB mainly include the metabolism of organic pollutants by AM fungi, the degradation of these pollutants by the enzymes derived from AM exudation and by the enhanced root exudation and rhizospheric microbial activity in the presence of AM, and the removal of the pollutants by plant uptake and accumulation. As a new approach for the remediation of contaminated soils, some aspects involved in AMB, e.g., the screening of high efficient AM fungi, efficacy of co-existing AM fungi, soil ageing, and plant uptake of organic pollutants from soils in the presence of AM, still need to be further investigated.

  17. [Response of arbuscular mycorrhizal fungal lipid metabolism to symbiotic signals in mycorrhiza].

    Science.gov (United States)

    Tian, Lei; Li, Yuanjing; Tian, Chunjie

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi play an important role in energy flow and nutrient cycling, besides their wide distribution in the cosystem. With a long co-evolution, AM fungi and host plant have formed a symbiotic relationship, and fungal lipid metabolism may be the key point to find the symbiotic mechanism in arbusculart mycorrhiza. Here, we reviewed the most recent progress on the interaction between AM fungal lipid metabolism and symbiotic signaling networks, especially the response of AM fungal lipid metabolism to symbiotic signals. Furthermore, we discussed the response of AM fungal lipid storage and release to symbiotic or non-symbiotic status, and the correlation between fungal lipid metabolism and nutrient transfer in mycorrhiza. In addition, we explored the feedback of the lipolysis process to molecular signals during the establishment of symbiosis, and the corresponding material conversion and energy metabolism besides the crosstalk of fungal lipid metabolism and signaling networks. This review will help understand symbiotic mechanism of arbuscular mycorrhiza fungi and further application in ecosystem.

  18. Glomus drummondii and G. walkeri, two new species of arbuscular mycorrhizal fungi (Glomeromycota).

    Science.gov (United States)

    Błaszkowski, Janusz; Renker, Carsten; Buscot, François

    2006-05-01

    Two new ectocarpic arbuscular mycorrhizal fungal species, Glomus drummondii and G. walkeri (Glomeromycota), found in maritime sand dunes of northern Poland and those adjacent to the Mediterranean Sea are described and illustrated. Mature spores of G. drummondii are pastel yellow to maize yellow, globose to subglobose, (58-)71(-85) micromdiam, or ovoid, 50-80x63-98 microm. Their wall consists of three layers: an evanescent, hyaline, short-lived outermost layer, a laminate, smooth, pastel yellow to maize yellow middle layer, and a flexible, smooth, hyaline innermost layer. Spores of G. walkeri are white to pale yellow, globose to subglobose, (55-)81(-95) micromdiam, or ovoid, 60-90x75-115 microm, and have a spore wall composed of three layers: a semi-permanent, hyaline outermost layer, a laminate, smooth, white to pale yellow middle layer, and a flexible, smooth, hyaline innermost layer. In Melzer's reagent, only the inner- and outermost layers stain reddish white to greyish rose in G. drummondii and G. walkeri, respectively. Both species form vesicular-arbuscular mycorrhizae in one-species cultures with Plantago lanceolata as the host plant. Phylogenetic analyses of the ITS and parts of the LSU of the nrDNA of spores placed both species in Glomus Group B sensu Schüssler et al. [Schüssler A, Schwarzott D, Walker C, 2001. A new fungal phylum, the Glomeromycota: phylogeny and evolution. Mycolological Research 105: 1413-1421.].

  19. Phosphorus effects on the mycelium and storage structures of an arbuscular mycorrhizal fungus as studied in the soil and roots by analysis of fatty acid signatures

    DEFF Research Database (Denmark)

    Olsson, P.A.; Bååth, E.; Jakobsen, I.

    1997-01-01

    The distribution of an arbuscular mycorrhizal (AM) fungus between soil and roots, and between mycelial and storage structures, was studied by use of the fatty acid signature 16:1 omega 5. Increasing the soil phosphorus level resulted in a decrease in the level of the fatty acid 16:1 omega 5 in the...... soil and roots. A similar decrease was detected by microscopic measurements of root colonization and of the length of AM fungal hyphae in the soil. The fatty acid 16:1 omega 5 was estimated from two types of lipids, phospholipids and neutral lipids, which mainly represent membrane lipids and storage...... lipids, respectively. The numbers of spores of the AM fungus formed in the soil correlated most closely, with neutral lipid fatty acid 16:1 omega 5, whereas the hyphal length in the soil correlated most closely with phospholipid fatty acid 16:1 omega 5. The fungal neutral lipid/phospholipid ratio in the...

  20. The Effects of Arbuscular Mycorrhizal Fungi Inoculation on Reactive Oxyradical Scavenging System of Soybean (Glycine max Nodules under Salt Stress Condition

    Directory of Open Access Journals (Sweden)

    Omid Younesi

    2014-01-01

    Full Text Available The effects of arbuscular mycorrhizal fungi (AMF, Glomus mosseae, on oxygen radical scavenging system (including superoxide dismutase (SOD, catalase (CAT, glutathione reductase (GR, ascorbate peroxidase (APX and peroxidase (POX in nodules of soybean (Glycine max plants under salt stress condition were studied in potted culture experiment. The experiment was arranged as a factorial in Randomized Complete Block Design (RCBD with four replications in greenhouse of College of Agriculture, Tehran University, Iran. Results indicated that AMF colonization notably increased the activities of SOD, CAT, POX and GR in the nodules, whereas it had little effect on APX. The results indicate that the AM fungus is capable of alleviating the damage caused by salt stress on symbiotic nitrogen fixation of soybean plants by increasing antioxidant enzyme activity. In conclusion, AMF could enhance the salinity tolerance of soybean plant, and thereby play a very important role in improving symbiotic nitrogen fixation and promoted plant growth.

  1. Arbuscular mycorrhizal fungi affect glucosinolate and mineral element composition in leaves of Moringa oleifera.

    Science.gov (United States)

    Cosme, Marco; Franken, Philipp; Mewis, Inga; Baldermann, Susanne; Wurst, Susanne

    2014-10-01

    Moringa is a mycorrhizal crop cultivated in the tropics and subtropics and appreciated for its nutritive and health-promoting value. As well as improving plant mineral nutrition, arbuscular mycorrhizal fungi (AMF) can affect plant synthesis of compounds bioactive against chronic diseases in humans. Rhizophagus intraradices and Funneliformis mosseae were used in a full factorial experiment to investigate the impact of AMF on the accumulation of glucosinolates, flavonoids, phenolic acids, carotenoids, and mineral elements in moringa leaves. Levels of glucosinolates were enhanced, flavonoids and phenolic acids were not affected, levels of carotenoids (including provitamin A) were species-specifically reduced, and mineral elements were affected differently, with only Cu and Zn being increased by the AMF. This study presents novel results on AMF effects on glucosinolates in leaves and supports conclusions that the impacts of these fungi on microelement concentrations in edible plants are species dependent. The nonspecific positive effects on glucosinolates and the species-specific negative effects on carotenoids encourage research on other AMF species to achieve general benefits on bioactive compounds in moringa. PMID:24706008

  2. Growth responses of maritime sand dune plant species to arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Mariusz Tadych

    2014-08-01

    Full Text Available In a pot experiment conducted in a greenhouse, the response of 6 plant species dominating in the succession of vegetation of a deflation hollow of the Łeba Bar to inoculation with arbuscular mycorrhizal fungi (AMF was investigated. The inoculum was a mixture of soil, roots and spores of 5 species of AMF with the dominant species Glomus aggregatum. Except for Corynephorus canescens and Festuca rubra subsp. arenaria, both the growth and the dry matter of above-ground parts of plants of Agrostis stolonifera, Ammophila arenaria, Corynephorus canescens, Juncus articulatus and J. balticus inoculated with AMF were higher than those growing in soils lacking infection propagules of these fungi. Inoculation with AMF decreased the dry matter of root: shoot ratios in 5 plant species. This property was not determined in Festuca rubra subsp. arenaria due to the death of all control plants. The level of mycorrhizal infection was low and did not correlate with the growth responses found. The high growth reaction of Juncus spp. to AMF found in this study suggests that the opinion of non-mycotrophy or low dependence of plants of Juncaceae on AMF was based on results of investigations of plants growing in wet sites known to inhibit the formation of mycorrhizae.

  3. Diversity of morphology and function in arbuscular mycorrhizal symbioses in Brachypodium distachyon.

    Science.gov (United States)

    Hong, Jeon J; Park, Yong-Soon; Bravo, Armando; Bhattarai, Kishor K; Daniels, Dierdra A; Harrison, Maria J

    2012-09-01

    Brachypodium distachyon is a grass species that serves as a useful model for wheat and also for many of the grass species proposed as feedstocks for bioenergy production. Here, we monitored B. distachyon symbioses with five different arbuscular mycorrhizal (AM) fungi and identified symbioses that vary functionally with respect to plant performance. Three symbioses promoted significant increases in shoot phosphorus (P) content and shoot growth of Brachypodium, while two associations were neutral. The Brachypodium/Glomus candidum symbiosis showed a classic 'Paris-type' morphology. In the other four AM symbioses, hyphal growth was exclusively intracellular and linear; hyphal coils were not observed and arbuscules were abundant. Expression of the Brachypodium ortholog of the symbiosis-specific phosphate (Pi) transporter MtPT4 did not differ significantly in these five interactions indicating that the lack of apparent functionality did not result from a failure to express this gene or several other AM symbiosis-associated genes. Analysis of the expression patterns of the complete PHT1 Pi transporter gene family and AMT2 gene family in B. distachyon/G. intraradices mycorrhizal roots identified additional family members induced during symbiosis and again, transcript levels were similar in the different Brachypodium AM symbioses. This initial morphological, molecular and functional characterization provides a framework for future studies of functional diversity in AM symbiosis in B. distachyon.

  4. Transcriptional responses of Medicago truncatula upon sulfur deficiency stress and arbuscular mycorrhizal symbios

    Directory of Open Access Journals (Sweden)

    Daniel eWipf

    2014-12-01

    Full Text Available Sulfur plays an essential role in plants’ growth and development and in their response to various abiotic and biotic stresses despite its leachability and its very low abundance in the only form that plant roots can uptake (sulfate. It is part of amino acids, glutathione (GSH, thiols of proteins and peptides, membrane sulfolipids, cell walls and secondary products, so reduced availability can drastically alter plant growth and development. The nutritional benefits of symbiotic interactions can help the plant in case of S deficiency. In particular the arbuscular mycorrhizal (AM interaction improves N, P and S plant nutrition, but the mechanisms behind these exchanges are not fully known yet. Although the transcriptional changes in the leguminous model plant Medicago truncatula have been already assessed in several biotic and/or abiotic conditions, S deficiency has not been considered so far. The aim of this work is to get a first overview on S-deficiency responses in the leaf and root tissues of plants interacting with the AM fungus Rhizophagus irregularis.Several hundred genes displayed significantly different transcript accumulation levels. Annotation and GO ID association were used to identify biological processes and molecular functions affected by sulfur starvation. Beside the beneficial effects of AM interaction, plants were greatly affected by the nutritional status, showing various differences in their transcriptomic footprints. Several pathways in which S plays an important role appeared to be differentially affected according to mycorrhizal status, with a generally reduced responsiveness to S deficiency in mycorrhized plants.

  5. Symbiont dynamics during ecosystem succession: co-occurring plant and arbuscular mycorrhizal fungal communities.

    Science.gov (United States)

    García de León, David; Moora, Mari; Öpik, Maarja; Neuenkamp, Lena; Gerz, Maret; Jairus, Teele; Vasar, Martti; Bueno, C Guillermo; Davison, John; Zobel, Martin

    2016-07-01

    Although mycorrhizas are expected to play a key role in community assembly during ecological succession, little is known about the dynamics of the symbiotic partners in natural systems. For instance, it is unclear how efficiently plants and arbuscular mycorrhizal (AM) fungi disperse into early successional ecosystems, and which, if either, symbiotic partner drives successional dynamics. This study describes the dynamics of plant and AM fungal communities, assesses correlation in the composition of plant and AM fungal communities and compares dispersal limitation of plants and AM fungi during succession. We studied gravel pits 20 and 50 years post abandonment and undisturbed grasslands in Western Estonia. The composition of plant and AM fungal communities was strongly correlated, and the strength of the correlation remained unchanged as succession progressed, indicating a stable dependence among mycorrhizal plants and AM fungi. A relatively high proportion of the AM fungal taxon pool was present in early successional sites, in comparison with the respective fraction of plants. These results suggest that AM fungi arrived faster than plants and may thus drive vegetation dynamics along secondary vegetation succession. PMID:27162183

  6. A unique mitovirus from Glomeromycota, the phylum of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Kitahara, Ryoko; Ikeda, Yoji; Shimura, Hanako; Masuta, Chikara; Ezawa, Tatsuhiro

    2014-08-01

    Arbuscular mycorrhizal (AM) fungi that belong to the phylum Glomeromycota associate with most land plants and supply mineral nutrients to the host plants. One of the four viral segments found by deep-sequencing of dsRNA in the AM fungus Rhizophagus clarus strain RF1 showed similarity to mitoviruses and is characterized in this report. The genome segment is 2,895 nucleotides in length, and the largest ORF was predicted by applying either the mold mitochondrial or the universal genetic code. The ORF encodes a polypeptide of 820 amino acids with a molecular mass of 91.2 kDa and conserves the domain of the mitovirus RdRp superfamily. Accordingly, the dsRNA was designated as R. clarus mitovirus 1 strain RF1 (RcMV1-RF1). Mitoviruses are localized exclusively in mitochondria and thus generally employ the mold mitochondrial genetic code. The distinct codon usage of RcMV1-RF1, however, suggests that the virus is potentially able to replicate not only in mitochondria but also in the cytoplasm. RcMV1-RF1 RdRp showed the highest similarity to the putative RdRp of a mitovirus-like ssRNA found in another AM fungus, followed by RdRp of a mitovirus in an ascomycotan ectomycorrhizal fungus. The three mitoviruses found in the three mycorrhizal fungi formed a deeply branching clade that is distinct from the two major clades in the genus Mitovirus.

  7. Protein actors sustaining arbuscular mycorrhizal symbiosis: underground artists break the silence.

    Science.gov (United States)

    Recorbet, Ghislaine; Abdallah, Cosette; Renaut, Jenny; Wipf, Daniel; Dumas-Gaudot, Eliane

    2013-07-01

    The roots of most land plants can enter a relationship with soil-borne fungi belonging to the phylum Glomeromycota. This symbiosis with arbuscular mycorrhizal (AM) fungi belongs to the so-called biotrophic interactions, involving the intracellular accommodation of a microorganism by a living plant cell without causing the death of the host. Although profiling technologies have generated an increasing depository of plant and fungal proteins eligible for sustaining AM accommodation and functioning, a bottleneck exists for their functional analysis as these experiments are difficult to carry out with mycorrhiza. Nonetheless, the expansion of gene-to-phenotype reverse genetic tools, including RNA interference and transposon silencing, have recently succeeded in elucidating some of the plant-related protein candidates. Likewise, despite the ongoing absence of transformation tools for AM fungi, host-induced gene silencing has allowed knockdown of fungal gene expression in planta for the first time, thus unlocking a technological limitation in deciphering the functional pertinence of glomeromycotan proteins during mycorrhizal establishment. This review is thus intended to draw a picture of our current knowledge about the plant and fungal protein actors that have been demonstrated to be functionally implicated in sustaining AM symbiosis mostly on the basis of silencing approaches.

  8. Effect of arbuscular mycorrhizal (AM) fungi on 137Cs uptake by plants grown on different soils

    International Nuclear Information System (INIS)

    The potential use of mycorrhiza as a bioremediation agent for soils contaminated by radiocesium was evaluated in a greenhouse experiment. The uptake of 137Cs by cucumber, perennial ryegrass, and sunflower after inoculation with a commercial arbuscular mycorrhizal (AM) product in soils contaminated with 137Cs was investigated, with non-mycorrhizal quinoa included as a “reference” plant. The effect of cucumber and ryegrass inoculation with AM fungi on 137Cs uptake was inconsistent. The effect of AM fungi was most pronounced in sunflower: both plant biomass and 137Cs uptake increased on loamy sand and loamy soils. The total 137Cs activity accumulated within AM host sunflower on loamy sand and loamy soils was 2.4 and 3.2-fold higher than in non-inoculated plants. Although the enhanced uptake of 137Cs by quinoa plants on loamy soil inoculated by the AM fungi was observed, the infection of the fungi to the plants was not confirmed. - Highlights: ► Effect of soil inoculation on 137Cs uptake by crops was studied in greenhouse. ► 137Cs uptake by inoculated sunflower plants was most pronounced. ► The higher 137Cs uptake by inoculated sunflower due to presence of mycorrhiza. ► Studies suggest potential for use of mycorrhiza on contaminated sites.

  9. Arbuscular mycorrhizal fungi affect glucosinolate and mineral element composition in leaves of Moringa oleifera.

    Science.gov (United States)

    Cosme, Marco; Franken, Philipp; Mewis, Inga; Baldermann, Susanne; Wurst, Susanne

    2014-10-01

    Moringa is a mycorrhizal crop cultivated in the tropics and subtropics and appreciated for its nutritive and health-promoting value. As well as improving plant mineral nutrition, arbuscular mycorrhizal fungi (AMF) can affect plant synthesis of compounds bioactive against chronic diseases in humans. Rhizophagus intraradices and Funneliformis mosseae were used in a full factorial experiment to investigate the impact of AMF on the accumulation of glucosinolates, flavonoids, phenolic acids, carotenoids, and mineral elements in moringa leaves. Levels of glucosinolates were enhanced, flavonoids and phenolic acids were not affected, levels of carotenoids (including provitamin A) were species-specifically reduced, and mineral elements were affected differently, with only Cu and Zn being increased by the AMF. This study presents novel results on AMF effects on glucosinolates in leaves and supports conclusions that the impacts of these fungi on microelement concentrations in edible plants are species dependent. The nonspecific positive effects on glucosinolates and the species-specific negative effects on carotenoids encourage research on other AMF species to achieve general benefits on bioactive compounds in moringa.

  10. Arbuscular mycorrhizal fungi for the biocontrol of plant-parasitic nematodes: a review of the mechanisms involved

    OpenAIRE

    Nele eSchouteden; Dirk eDe Waele; Bart ePanis; Christine M Vos

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and dis...

  11. Arbuscular mycorrhizal fungi for the biocontrol of plant-parasitic nematodes: a review of the mechanisms involved

    OpenAIRE

    Schouteden, Nele; de Waele, Dirk; Panis, Bart; Christine M Vos

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and dis...

  12. Diversity patterns of indigenous arbuscular mycorrhizal fungi associated with rhizosphere of cowpea (Vigna unguiculata (L.) Walp.) in Benin, West Africa

    OpenAIRE

    Johnson, J. M.; Houngnandan, P.; A. Kane; Sanon, K. B.; Neyra, Marc

    2013-01-01

    Assessment of diversity and understanding factors underlying species distribution are fundamental themes in ecology. However, the diversity of native arbuscular mycorrhizal fungi (AMF) species in African tropical agro-ecosystems remains weakly known. This research was carried out to assess the morphological diversity of indigenous AMF species associated with rhizosphere of cowpea (Vigna unguiculata (L) Walp.) in different agro-ecological zones (AEZ) of Benin and to examine the effects of soil...

  13. Two putative-aquaporin genes are differentially expressed during arbuscular mycorrhizal symbiosis in Lotus japonicus

    OpenAIRE

    Giovannetti Marco; Balestrini Raffaella; Volpe Veronica; Guether Mike; Straub Daniel; Costa Alex; Ludewig Uwe; Bonfante Paola

    2012-01-01

    Abstract Background Arbuscular mycorrhizas (AM) are widespread symbioses that provide great advantages to the plant, improving its nutritional status and allowing the fungus to complete its life cycle. Nevertheless, molecular mechanisms that lead to the development of AM symbiosis are not yet fully deciphered. Here, we have focused on two putative aquaporin genes, LjNIP1 and LjXIP1, which resulted to be upregulated in a transcriptomic analysis performed on mycorrhizal roots of Lotus japonicus...

  14. Impact of an invasive nitrogen-fixing tree on arbuscular mycorrhizal fungi and the development of native species

    OpenAIRE

    Guisande-Collazo, Alejandra; González, Luís; Souza-Alonso, Pablo

    2016-01-01

    This study contributes to knowledge on the effect of the invasive N2-fixing tree, Acacia dealbata, on soil microbial communities and consequences on plant species that are dependent on symbiotic relationships as in the case of Plantago lanceolata. The main results of this work indicate that Acacia dealbata modifies the structure of arbuscular mycorrhizal fungi in the invaded shrublands and consequently the growth and development of plants that depend on AMF. Plantago lanceolata showed a subst...

  15. Phosphate transport by hyphae of field communities of arbuscular mycorrhizal fungi at two levels of P fertilization

    DEFF Research Database (Denmark)

    Thingstrup, I.; Kahiluoto, H.; Jakobsen, I.

    2000-01-01

    This study was conducted to elucidate the effect of P fertilisation on the function of field communities of arbuscular mycorrhizal fungi (AMF) measured as P transport to flax. Two methods were applied to soil from a long-term field experiment with NaHCO3-extractable soil P levels of 24 and 50 mg kg...... was largely similar in both fertilization treatments, indicating that the capacity for P uptake and transport by hyphae of the two AMF communities was similar....

  16. Influence of arbuscular mycorrhizal fungi and the expression of K+/Cs+ transporters on the accumulation of caesium by plants

    OpenAIRE

    Wiesel, Lea

    2011-01-01

    Radiocaesium (134Cs, 137Cs) is of environmental concern because of its incorporation into the food chain and prolonged emission of harmful radiation. Plants take up caesium via cation transporters which cannot discriminate between radioactive and stable caesium (133Cs). Around 80% of angiosperms live in symbiosis with arbuscular mycorrhizal (AM) fungi that deliver mineral nutrients to their hosts. Contrasting effects of AM fungi on caesium accumulation by plants have been reported. The ultima...

  17. Variability in growth, nutrition and phytochemical constituents of Plectranthus amboinicus (Lour) Spreng. as influenced by indigenous arbuscular mycorrhizal fungi

    OpenAIRE

    Sevanan Rajeshkumar

    2008-01-01

    A study was conducted under greenhouse nursery condition on the efficacy of seven indigenous arbuscular mycorrhizal (AM) fungi in the improvement of growth, biomass, nutrition and phytochemical constituents, namely total phenols, ortho dihydroxy phenols, flavonoids, alkaloids, tannins and saponins, in the roots and leaves of Plectranthus amboinicus (Lour) Spreng. Seedlings were raised in polythene bags containing soil inoculated with isolates of seven different indigenous AM fungi, viz. Acaul...

  18. The influence of arbuscular mycorrhizal fungi inoculation on yam (Dioscorea spp.) tuber weights and secondary metabolite content

    OpenAIRE

    Lu, Fun-Chi; Lee, Chen-Yu; Wang, Chun-Li

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) are widely distributed in nature. They live in the roots of higher plants, in a symbiotic relationship. In this study, five commercial species of yams (Dioscorea spp.) were inoculated with six species of AMF, Glomus clarum, G. etunicatum, G. fasciculatum, Gigaspora sp., G. mosseae, and Acaulospora sp., in field cultivation conditions to investigate the influence of AMF inoculation on tuber weights and secondary metabolite content in yam tubers. The results s...

  19. Inoculations with Arbuscular Mycorrhizal Fungi Increase Vegetable Yields and Decrease Phoxim Concentrations in Carrot and Green Onion and Their Soils

    OpenAIRE

    Fa Yuan Wang; Rui Jian Tong; Zhao Yong Shi; Xiao Feng Xu; Xin Hua He

    2011-01-01

    BACKGROUND: As one of the most widely used organophosphate insecticides in vegetable production, phoxim (C(12)H(15)N(2)O(3)PS) is often found as residues in crops and soils and thus poses a potential threat to public health and environment. Arbuscular mycorrhizal (AM) fungi may make a contribution to the decrease of organophosphate residues in crops and/or the degradation in soils, but such effects remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: A greenhouse pot experiment studied the influen...

  20. [Effect of Ryegrass and Arbuscular Mycorrhizal on Cd Absorption by Varieties of Tomatoes and Cadmium Forms in Soil].

    Science.gov (United States)

    Chen, Yong-qin; Jiang, Ling; Xu, Wei-hong; Chi, Sun-lin; Chen, Xu-gen; Xie, Wen-wen; Xiong, Shi- juan; Zhang, Jin-zhong; Xiong, Zhi-ting

    2015-12-01

    Field trial was carried out to investigate the effects of ryegrass and arbuscular mycorrhizal single or compound treatment to two varieties of tomato ("Defu mm-8" and "Luobeiqi") on the plant growth, concentrations and accumulations of Cd as well as the impact on microorganisms, enzyme activities, pH and Cd forms in soil when exposed to Cd (5.943 mg · kg⁻¹). The results showed that dry weights of fruit, root, stem, leaf and plant significantly increased by single or compound treatment of ryegrass and arbuscular mycorrhizal by 14.1%-38.4% and 4.2%-18.3%, 20.9%-31.5% and 8.4%-10.3%, 13.0%-16.8% and 3.0%-9.5%, 10.7%- 16.8% and 2.7%-7.6%, 14.3%-36.6% and 4.5%-16.8%, respectively. The amounts of bacteria, fungi, actinomycetes of soil and the activities of urease, invertase, acid phosphatase, catalase in soil were increased by single or compound treatment of ryegrass and arbuscular mycorrhizal, and the soil microorganism amounts and enzyme activities significantly differed between the two varieties of tomato and treatments (P Cd, CAB-Cd, Fe-Mn-Cd and total Cd in soil were decreased, and the total Cd content was decreased by 16.9%-27.8%. Cadmium concentrations in fruit, leaf, stem and root of both varieties were significantly decreased by 6.9%-40.9%, 5.7%-40.1%, 4.6%-34.7% and 9.8%-42.4%, respectively. Cadmium accumulations in tomato were in order of leaf > stem > root > fruit. Comparing the two tomato varieties, Cd concentrations and Cd accumulations in fruit and plant were in order of "Luobeiqi" < "Defu mm-8" in the presence or absence of single or compound treatment of ryegrass and arbuscular mycorrhizal.

  1. Modularity Reveals the Tendency of Arbuscular Mycorrhizal Fungi To Interact Differently with Generalist and Specialist Plant Species in Gypsum Soils

    OpenAIRE

    Torrecillas, Emma; del Mar Alguacil, Maria; Roldán, Antonio; Díaz, Gisela; Montesinos-Navarro, Alicia; Torres, Maria Pilar

    2014-01-01

    Patterns in plant–soil biota interactions could be influenced by the spatial distribution of species due to soil conditions or by the functional traits of species. Gypsum environments usually constitute a mosaic of heterogeneous soils where gypsum and nongypsum soils are imbricated at a local scale. A case study of the interactions of plants with arbuscular mycorrhizal fungi (AMF) in gypsum environments can be illustrative of patterns in biotic interactions. We hypothesized that (i) soil char...

  2. Indetification of Symbiotic Arbuscular Mycorrhizal Fungi in Korea by Morphological and DNA Sequencing Features of Their Spores

    OpenAIRE

    Kim, Dong-hun; Eom, An-Heum; Lee, Jeong-Woo; Leonowicz, Andrzej; Ohaga, Shoji

    2006-01-01

    In order to clarify the diversity of the arbuscular mycorrhizal fungi, 9 individual plant roots and soils were randomly chosen at 27 sites in the general cultivation fields in the Chungbuk- and Chungnam- provinces, middle parts of Korea. In terms of height growth of Sorghum bicolor, the soil in Cheongwon site (host plant Fagopyrum esculentum) resulted in the best growth, and the order of growth was Platycodon grandiflorus, Miscanthus sinensis, Sesamum indicum, and Capsicum annuum. It represen...

  3. Effects of arbuscular mycorrhizal fungus on net ion fluxes in the roots of trifoliate orange(Poncirus trifoliata) and mineral nutrition in seedlings under zinc contamination%丛枝菌根真菌对枳根净离子流及锌污染下枳苗矿质营养的影响

    Institute of Scientific and Technical Information of China (English)

    肖家欣; 杨慧; 张绍铃

    2012-01-01

    We investigated the effects of arbuscular mycorrhizal fungus inoculation on net ion flux in the roots of trifoliate orange ( Poncirus trifoliata ( L. ) Raf. ) and mineral nutrition in seedlings under zinc contamination. A pot experiment was conducted to study plant growth as well as the distribution of zinc, copper, phosphorus, potassium, calcium, and magnesium in trifoliate orange seedlings inoculated by the arbuscular mycorrhizal fungus, Glomus intraradices, under greenhouse conditions. Plants were grown in yellow soil:quartz sand (9:1 , v/v) medium and were irrigated with solutions containing three different zinc concentrations (0, 300 and 600 mg/kg) , which corresponded to control, medium and high zinc contamination treatments, respectively. Meanwhile, a non-invasive micro-test technique was used to determine the net fluxes of Ca2+, H+ and NO-3 along mycorrhizal and non-mycorrhizal roots of trifoliate orange seedlings grown in medium with no zinc added. Arbuscular mycorrhizal colonization significantly increased the fresh weight of shoots and roots exposed todifferent zinc levels. With increasing zinc concentrations, the myeorrhizal colonization percentage decreased, while the zinc levels in the shoots and roots progressively increased. Zinc concentrations in the roots were significantly higher in arbuscular myeorrhizal seedlings than in non-arbuscular myeorrhizal seedlings. The shoot/root ratios of the zinc translocation coefficient gradually decreased in arbuscular myeorrhizal seedlings with increasing zinc concentrations. This indicated that at medium or high levels of zinc contamination, a lot of zinc was immobilized in roots through the establishment of mycorrhizae. Therefore, phytotoxicity might be alleviated. Copper, phosphorus, potassium, and magnesium concentrations in shoots of plants grown in medium with no added zinc were significantly higher in arbuscular myeorrhizal seedlings than those in non-arbuscular myeorrhizal seedlings. Similarly, copper

  4. EFECTO DE HONGOS MICORRIZICOS ARBUSCULARES EN PLÁNTULAS DE Elaeis guineensis (Palmaceae CON ALTO NIVEL DE P EN EL SUELO EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGI IN Elaeis guineensis (Palmaceae SEEDLINGS WITH HIGH PHOSPHORUS LEVEL IN THE SOIL

    Directory of Open Access Journals (Sweden)

    SILVIA EUGENIA BARRERA BERDUGO

    agroecosytems. The aim of this work was to evaluate the effect between native and commercial arbuscular mycorrhizal fungi and Elaeis guineensis seedlings in greenhouse conditions with high P level. Plants of three months of the age were put under four treatments: Native inoculate (NI, Foreign inoculate (FI, Mixture (M and control (TA. It was evaluated total dry weight of the plant, root and aerial part dry weight, height of the plant, relative growth rate (RGR, mycorrhizal colonization and spores number. At 45 and 90 days after the transplant these variable were evaluated. An initial sampling dry mass was taking by to determine RGR. The data were analyzed through the ANOVA or Kruskall-Wallis according to the behavior of the data, followed of a test of averages of Duncan or a modified test of Tuckey for nonparametric data. Significant differences in the spores number between the treatments NI, FI, M and TA and between NI and M to the 45 days appeared. In the colonization mycorrhizal differences between the treatments FA and TA were observed the 45 days. To the 90 days between all the treatments with respect to the TA. Although the P level in the soil was high, also it was it the mycorrhizal colonization at the two evaluated times. Through time the treatment NI worked better in the soil edaphic conditions used in this experiment.

  5. Assessment of arbuscular mycorrhizal fungi status and heavy metal accumulation characteristics of tree species in a lead-zinc mine area: potential applications for phytoremediation.

    Science.gov (United States)

    Yang, Yurong; Liang, Yan; Ghosh, Amit; Song, Yingying; Chen, Hui; Tang, Ming

    2015-09-01

    To select suitable tree species associated with arbuscular mycorrhizal fungi (AMF) for phytoremediation of heavy metal (HM) contaminated area, we measured the AMF status and heavy metal accumulation in plant tissues in a lead-zinc mine area, Northwest China. All 15 tree species were colonized by AM fungi in our investigation. The mycorrhizal frequency (F%), mycorrhizal colonization intensity (M%) and spore density (SP) reduced concomitantly with increasing Pb and Zn levels; however, positive correlations were found between arbuscule density (A%) and soil total/DTPA-extractable Pb concentrations. The average concentrations of Pb, Zn, Cu and Cd in plant samples were 168.21, 96.61, 41.06, and 0.79 mg/kg, respectively. Populus purdomii Rehd. accumulated the highest concentrations of Zn (432.08 mg/kg) and Cu (140.85 mg/kg) in its leaves. Considerable amount of Pb (712.37 mg/kg) and Cd (3.86 mg/kg) were concentrated in the roots of Robinia pseudoacacia Linn. and Populus simonii Carr., respectively. Plants developed different strategies to survive in HM stress environment: translocating more essential metals (Zn and Cu) into the aerial parts, while retaining more toxic heavy metals (Pb and Cd) in the roots to protect the above-ground parts from damage. According to the translocation factor (TF), bioconcentration factor (BCF), growth rate and biomass production, five tree species (Ailanthus altissima (Mill.) Swingle, Cotinus coggygria Scop., P. simonii, P. purdomii, and R. pseudoacacia) were considered to be the most suitable candidates for phytoextraction and/or phytostabilization purposes. Redundancy analysis (RDA) showed that the efficiency of phytoremediation was enhanced by AM symbioses, and soil pH, Pb, Zn, and Cd levels were the main factors influencing the HM accumulation characteristics of plants.

  6. Assessment of arbuscular mycorrhizal fungi status and heavy metal accumulation characteristics of tree species in a lead-zinc mine area: potential applications for phytoremediation.

    Science.gov (United States)

    Yang, Yurong; Liang, Yan; Ghosh, Amit; Song, Yingying; Chen, Hui; Tang, Ming

    2015-09-01

    To select suitable tree species associated with arbuscular mycorrhizal fungi (AMF) for phytoremediation of heavy metal (HM) contaminated area, we measured the AMF status and heavy metal accumulation in plant tissues in a lead-zinc mine area, Northwest China. All 15 tree species were colonized by AM fungi in our investigation. The mycorrhizal frequency (F%), mycorrhizal colonization intensity (M%) and spore density (SP) reduced concomitantly with increasing Pb and Zn levels; however, positive correlations were found between arbuscule density (A%) and soil total/DTPA-extractable Pb concentrations. The average concentrations of Pb, Zn, Cu and Cd in plant samples were 168.21, 96.61, 41.06, and 0.79 mg/kg, respectively. Populus purdomii Rehd. accumulated the highest concentrations of Zn (432.08 mg/kg) and Cu (140.85 mg/kg) in its leaves. Considerable amount of Pb (712.37 mg/kg) and Cd (3.86 mg/kg) were concentrated in the roots of Robinia pseudoacacia Linn. and Populus simonii Carr., respectively. Plants developed different strategies to survive in HM stress environment: translocating more essential metals (Zn and Cu) into the aerial parts, while retaining more toxic heavy metals (Pb and Cd) in the roots to protect the above-ground parts from damage. According to the translocation factor (TF), bioconcentration factor (BCF), growth rate and biomass production, five tree species (Ailanthus altissima (Mill.) Swingle, Cotinus coggygria Scop., P. simonii, P. purdomii, and R. pseudoacacia) were considered to be the most suitable candidates for phytoextraction and/or phytostabilization purposes. Redundancy analysis (RDA) showed that the efficiency of phytoremediation was enhanced by AM symbioses, and soil pH, Pb, Zn, and Cd levels were the main factors influencing the HM accumulation characteristics of plants. PMID:25929455

  7. Cadmium effect on the association of jackbean (Canavalia ensiformis and arbuscular mycorrhizal fungi Efeito do cadmio na associação de feijão de porco (Canavalia ensiformis e fungos micorrízicos arbusculares

    Directory of Open Access Journals (Sweden)

    Sara Adrián López de Andrade

    2005-08-01

    Full Text Available The effect of cadmium (Cd on mycorrhizal association and on shoot and root Cd concentration was investigated in jackbean plants under hydroponic conditions. The treatments consisted of the inoculation of three different species of arbuscular mycorrhizal fungi (AMF, Glomus etunicatum, G. intraradices and G. macrocarpum, and a non-inoculated control, two Cd (0 and 5 µmol L-1 and two P (1 and 10 mg L-1 levels in the nutrient solution. Mycorrhizal colonization, length of AMF extraradical mycelium, guaiacol peroxidase activity in roots, plant growth and root and shoot Cd and P concentrations were determined. Mycorrhizal status did not promote jackbean growth but in most of the cases mycorrhization increased root and shoot Cd concentrations. Cd ions were accumulated mainly in roots and only small amounts were translocated to the shoot. Cd addition did not affect root colonization by AMF but the AM extraradical mycelium (ERM was sensitive to the added Cd. ERM length was reduced by 25% in the presence of Cd. This reduction was more pronounced under conditions of low P concentration. Also at this P concentration, Cd addition decreased guaiacol peroxidase activity in non-mycorrhizal roots and in roots colonized by G. macrocarpum. However, mycorrhizal roots maintained lower values of peroxidase activity. G. etunicatum showed the best performance when associated to jackbean plants and it could be a promising association for phytoremediation of Cd- contaminated soil.O efeito do cádmio na associação micorrízica e no teor e acúmulo de Cd na raiz e parte aérea de feijão de porco foi avaliado em condição de hidroponia. Os tratamentos consistiram da inoculação ou não de três espécies de fungos micorrízicos arbusculares (FMAs, Glomus etunicatum, G. intraradices e G. macrocarpum, e uma testemunha (ausência de FMA, duas concentrações de Cd ( 0 e 5 µmol L-1 e de P (1 e 10 mg L-1 na solução nutritiva. Foram determinados a colonização micorr

  8. Arbuscular Mycorrhizal Fungal Mediation of Plant-Plant Interactions in a Marshland Plant Community

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2014-01-01

    Full Text Available Obligate aerobic AMF taxa have high species richness under waterlogged conditions, but their ecological role remains unclear. Here we focused on AM fungal mediation of plant interactions in a marshland plant community. Five cooccurring plant species were chosen for a neighbor removal experiment in which benomyl was used to suppress AMF colonization. A Phragmites australis removal experiment was also performed to study its role in promoting AMF colonization by increasing rhizosphere oxygen concentration. Mycorrhizal fungal effects on plant interactions were different for dominant and subdominant plant species. AMF colonization has driven positive neighbor effects for three subdominant plant species including Kummerowia striata, Leonurus artemisia, and Ixeris polycephala. In contrast, AMF colonization enhanced the negative effects of neighbors on the dominant Conyza canadensis and had no significant impact on the neighbor interaction to the dominant Polygonum pubescens. AM colonization was positively related to oxygen concentration. P. australis increased oxygen concentration, enhanced AMF colonization, and was thus indirectly capable of influencing plant interactions. Aerobic AM fungi appear to be ecologically relevant in this wetland ecosystem. They drive positive neighbor interactions for subdominant plant species, effectively increasing plant diversity. We suggest, therefore, that AM fungi may be ecologically important even under waterlogged conditions.

  9. Arbuscular mycorrhizal fungal mediation of plant-plant interactions in a marshland plant community.

    Science.gov (United States)

    Zhang, Qian; Sun, Qixiang; Koide, Roger T; Peng, Zhenhua; Zhou, Jinxing; Gu, Xungang; Gao, Weidong; Yu, Meng

    2014-01-01

    Obligate aerobic AMF taxa have high species richness under waterlogged conditions, but their ecological role remains unclear. Here we focused on AM fungal mediation of plant interactions in a marshland plant community. Five cooccurring plant species were chosen for a neighbor removal experiment in which benomyl was used to suppress AMF colonization. A Phragmites australis removal experiment was also performed to study its role in promoting AMF colonization by increasing rhizosphere oxygen concentration. Mycorrhizal fungal effects on plant interactions were different for dominant and subdominant plant species. AMF colonization has driven positive neighbor effects for three subdominant plant species including Kummerowia striata, Leonurus artemisia, and Ixeris polycephala. In contrast, AMF colonization enhanced the negative effects of neighbors on the dominant Conyza canadensis and had no significant impact on the neighbor interaction to the dominant Polygonum pubescens. AM colonization was positively related to oxygen concentration. P. australis increased oxygen concentration, enhanced AMF colonization, and was thus indirectly capable of influencing plant interactions. Aerobic AM fungi appear to be ecologically relevant in this wetland ecosystem. They drive positive neighbor interactions for subdominant plant species, effectively increasing plant diversity. We suggest, therefore, that AM fungi may be ecologically important even under waterlogged conditions.

  10. The Interaction between Arbuscular Mycorrhizal Fungi and Endophytic Bacteria Enhances Plant Growth of Acacia gerrardii under Salt Stress

    Science.gov (United States)

    Hashem, Abeer; Abd_Allah, Elsayed F.; Alqarawi, Abdulaziz A.; Al-Huqail, Asma A.; Wirth, Stephan; Egamberdieva, Dilfuza

    2016-01-01

    Microbes living symbiotically in plant tissues mutually cooperate with each other by providing nutrients for proliferation of the partner organism and have a beneficial effect on plant growth. However, few studies thus far have examined the interactive effect of endophytic bacteria and arbuscular mycorrhizal fungi (AMF) in hostile conditions and their potential to improve plant stress tolerance. In this study, we investigated how the synergistic interactions of endophytic bacteria and AMF affect plant growth, nodulation, nutrient acquisition and stress tolerance of Acacia gerrardii under salt stress. Plant growth varied between the treatments with both single inoculants and was higher in plants inoculated with the endophytic B. subtilis strain than with AMF. Co-inoculated A. gerrardii had a significantly greater shoot and root dry weight, nodule number, and leghemoglobin content than those inoculated with AMF or B. subtilis alone under salt stress. The endophytic B. subtilis could alleviate the adverse effect of salt on AMF colonization. The differences in nitrate and nitrite reductase and nitrogenase activities between uninoculated plants and those inoculated with AMF and B. subtilis together under stress were significant. Both inoculation treatments, either B. subtilis alone or combined with AMF, enhanced the N, P, K, Mg, and Ca contents and phosphatase activities in salt-stressed A. gerrardii tissues and reduced Na and Cl concentration, thereby protecting salt-stressed plants from ionic and osmotic stress-induced changes. In conclusion, our results indicate that endophytic bacteria and AMF contribute to a tripartite mutualistic symbiosis in A. gerrardii and are coordinately involved in the plant adaptation to salt stress tolerance. PMID:27486442

  11. Arbuscular mycorrhizal fungi (Glomeromycota associated with roots of Ammophila arenaria growing in maritime dunes of Bornholm (Denmark

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    Janusz Błaszkowski

    2011-05-01

    Full Text Available 155 rhizosphere soil and root mixtures were collected from under Ammophila arenaria colonizing maritime dunes of the island Bornholm (Denmark to determine arbuscular mycorrhizal fungi (AMF of the phylum Glomeromycota co-existing with this plant. In the laboratory, each mixture was divided into two parts. One part was used to establish a pot culture with Plantago lanceolata as the host plant to initiate sporulation of fungi that had not produced spores in field conditions. In the second part, the numerical and species composition of the spore populations of AMF sporulating in the field was determined. Spores of AMF were found in 70 field-collected samples and 134 trap cultures. They represented 26 species and six undescribed morphotypes in six genera of the Glomeromycota. Of them, 20 species and three morphotypes in five genera occurred in the field, and 16 species and three morphotypes in five genera were found in trap cultures. The fungi most frequently revealed were members of the genus Glomus; a total of 17 species and six morphotypes of this genus were recognized. Considering the occurrence of spores in both field samples and trap cultures, the fungi most frequently co-occurring with roots of A. arenaria growing in the dunes of Bornholm were G. irregulare (present in 73.6% of samples, followed by Scutellospora dipurpurescens (19.4% and Archaeospora trappei (10.3%. However, Glomus irregulare mainly sporulated in trap cultures; spores of this fungus were found in only 0.6% of field samples. Other relatively frequently found species were G. aggregatum (9.0%, G. eburneum (7.1%, Paraglomus laccatum (5.2%, and S. armeniaca (6.5%. The species most abundantly sporulating in the field were G. aggregatum (produced 28.36% of all spores isolated, G. badium (11.00%, and S. dipurpurescens (21.55%.

  12. Arbuscular Mycorrhizal Fungus Species Dependency Governs Better Plant Physiological Characteristics and Leaf Quality of Mulberry (Morus alba L.) Seedlings.

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    Shi, Song-Mei; Chen, Ke; Gao, Yuan; Liu, Bei; Yang, Xiao-Hong; Huang, Xian-Zhi; Liu, Gui-Xi; Zhu, Li-Quan; He, Xin-Hua

    2016-01-01

    Understanding the synergic interactions between arbuscular mycorrhizal fungi (AMF) and its host mulberry (Morus alba L.), an important perennial multipurpose plant, has theoretical and practical significance in mulberry plantation, silkworm cultivation, and relevant textile industry. In a greenhouse study, we compared functional distinctions of three genetically different AMF species (Acaulospora scrobiculata, Funneliformis mosseae, and Rhizophagus intraradices) on physiological and growth characteristics as well as leaf quality of 6-month-old mulberry seedlings. Results showed that mulberry was AMF-species dependent, and AMF colonization significantly increased shoot height and taproot length, stem base and taproot diameter, leaf and fibrous root numbers, and shoot and root biomass production. Meanwhile, leaf chlorophyll a or b and carotenoid concentrations, net photosynthetic rate, transpiration rate and stomatal conductance were generally significantly greater, while intercellular CO2 concentration was significantly lower in AMF-inoculated seedlings than in non-AMF-inoculated counterparts. These trends were also generally true for leaf moisture, total nitrogen, all essential amino acids, histidine, proline, soluble protein, sugar, and fatty acid as they were significantly increased under mycorrhization. Among these three tested AMFs, significantly greater effects of AMF on above-mentioned mulberry physiological and growth characteristics ranked as F. mosseae > A. scrobiculata > R. intraradices, whilst on mulberry leaf quality (e.g., nutraceutical values) for better silkworm growth as F. mosseae ≈A. scrobiculata > R. intraradices. In conclusion, our results showed that greater mulberry biomass production, and nutritional quality varied with AMF species or was AMF-species dependent. Such improvements were mainly attributed to AMF-induced positive alterations of mulberry leaf photosynthetic pigments, net photosynthetic rate, transpiration rate, and N

  13. Arbuscular Mycorrhizal Fungus Species Dependency Governs Better Plant Physiological Characteristics and Leaf Quality of Mulberry (Morus alba L.) Seedlings

    Science.gov (United States)

    Shi, Song-Mei; Chen, Ke; Gao, Yuan; Liu, Bei; Yang, Xiao-Hong; Huang, Xian-Zhi; Liu, Gui-Xi; Zhu, Li-Quan; He, Xin-Hua

    2016-01-01

    Understanding the synergic interactions between arbuscular mycorrhizal fungi (AMF) and its host mulberry (Morus alba L.), an important perennial multipurpose plant, has theoretical and practical significance in mulberry plantation, silkworm cultivation, and relevant textile industry. In a greenhouse study, we compared functional distinctions of three genetically different AMF species (Acaulospora scrobiculata, Funneliformis mosseae, and Rhizophagus intraradices) on physiological and growth characteristics as well as leaf quality of 6-month-old mulberry seedlings. Results showed that mulberry was AMF-species dependent, and AMF colonization significantly increased shoot height and taproot length, stem base and taproot diameter, leaf and fibrous root numbers, and shoot and root biomass production. Meanwhile, leaf chlorophyll a or b and carotenoid concentrations, net photosynthetic rate, transpiration rate and stomatal conductance were generally significantly greater, while intercellular CO2 concentration was significantly lower in AMF-inoculated seedlings than in non-AMF-inoculated counterparts. These trends were also generally true for leaf moisture, total nitrogen, all essential amino acids, histidine, proline, soluble protein, sugar, and fatty acid as they were significantly increased under mycorrhization. Among these three tested AMFs, significantly greater effects of AMF on above-mentioned mulberry physiological and growth characteristics ranked as F. mosseae > A. scrobiculata > R. intraradices, whilst on mulberry leaf quality (e.g., nutraceutical values) for better silkworm growth as F. mosseae ≈A. scrobiculata > R. intraradices. In conclusion, our results showed that greater mulberry biomass production, and nutritional quality varied with AMF species or was AMF-species dependent. Such improvements were mainly attributed to AMF-induced positive alterations of mulberry leaf photosynthetic pigments, net photosynthetic rate, transpiration rate, and N

  14. The Interaction between Arbuscular Mycorrhizal Fungi and Endophytic Bacteria Enhances Plant Growth of Acacia gerrardii under Salt Stress.

    Science.gov (United States)

    Hashem, Abeer; Abd Allah, Elsayed F; Alqarawi, Abdulaziz A; Al-Huqail, Asma A; Wirth, Stephan; Egamberdieva, Dilfuza

    2016-01-01

    Microbes living symbiotically in plant tissues mutually cooperate with each other by providing nutrients for proliferation of the partner organism and have a beneficial effect on plant growth. However, few studies thus far have examined the interactive effect of endophytic bacteria and arbuscular mycorrhizal fungi (AMF) in hostile conditions and their potential to improve plant stress tolerance. In this study, we investigated how the synergistic interactions of endophytic bacteria and AMF affect plant growth, nodulation, nutrient acquisition and stress tolerance of Acacia gerrardii under salt stress. Plant growth varied between the treatments with both single inoculants and was higher in plants inoculated with the endophytic B. subtilis strain than with AMF. Co-inoculated A. gerrardii had a significantly greater shoot and root dry weight, nodule number, and leghemoglobin content than those inoculated with AMF or B. subtilis alone under salt stress. The endophytic B. subtilis could alleviate the adverse effect of salt on AMF colonization. The differences in nitrate and nitrite reductase and nitrogenase activities between uninoculated plants and those inoculated with AMF and B. subtilis together under stress were significant. Both inoculation treatments, either B. subtilis alone or combined with AMF, enhanced the N, P, K, Mg, and Ca contents and phosphatase activities in salt-stressed A. gerrardii tissues and reduced Na and Cl concentration, thereby protecting salt-stressed plants from ionic and osmotic stress-induced changes. In conclusion, our results indicate that endophytic bacteria and AMF contribute to a tripartite mutualistic symbiosis in A. gerrardii and are coordinately involved in the plant adaptation to salt stress tolerance. PMID:27486442

  15. The intercropping partner affects arbuscular mycorrhizal fungi and Fusarium oxysporum f. sp. lycopersici interactions in tomato.

    Science.gov (United States)

    Hage-Ahmed, Karin; Krammer, Johannes; Steinkellner, Siegrid

    2013-10-01

    Arbuscular mycorrhizal fungi (AMF) and their bioprotective aspects are of great interest in the context of sustainable agriculture. Combining the benefits of AMF with the utilisation of plant species diversity shows great promise for the management of plant diseases in environmentally compatible agriculture. In the present study, AMF were tested against Fusarium oxysporum f. sp. lycopersici with tomato intercropped with either leek, cucumber, basil, fennel or tomato itself. Arbuscular mycorrhizal (AM) root colonisation of tomato was clearly affected by its intercropping partners. Tomato intercropped with leek showed even a 20 % higher AM colonisation rate than tomato intercropped with tomato. Positive effects of AMF expressed as an increase of tomato biomass compared to the untreated control treatment could be observed in root as well as in shoot weights. A compensation of negative effects of F. oxysporum f. sp. lycopersici on tomato biomass by AMF was observed in the tomato/leek combination. The intercropping partners leek, cucumber, basil and tomato had no effect on F. oxysporum f. sp. lycopersici disease incidence or disease severity indicating no allelopathic suppression; however, tomato co-cultivated with tomato clearly showed a negative effect on one plant/pot with regard to biomass and disease severity of F. oxysporum f. sp. lycopersici. Nonetheless, bioprotective effects of AMF resulting in the decrease of F. oxysporum f. sp. lycopersici disease severity were evident in treatments with AMF and F. oxysporum f. sp. lycopersici co-inoculation. However, these bioprotective effects depended on the intercropping partner since these effects were only observed in the tomato/leek and tomato/basil combination and for the better developed plant of tomato/tomato. In conclusion, the effects of the intercropping partner on AMF colonisation of tomato are of great interest for crop plant communities and for the influences on each other. The outcome of the bioprotective

  16. Arbuscular mycorrhizal fungi facilitate the invasion of Solidago canadensis L. in southeastern China

    Science.gov (United States)

    Yang, Ruyi; Zhou, Gang; Zan, Shuting; Guo, Fuyu; Su, Nannan; Li, Jing

    2014-11-01

    The significance of arbuscular mycorrhizal fungi (AMF) in the process of plant invasion is still poorly understood. We hypothesize that invasive plants would change local AMF community structure in a way that would benefit themselves but confer less advantages to native plants, thus influencing the extent of plant interactions. An AMF spore community composed of five morphospecies of Glomus with equal density (initial AMF spore community, I-AMF) was constructed to test this hypothesis. The results showed that the invasive species, Solidago canadensis, significantly increased the relative abundance of G. geosperum and G. etunicatum (altered AMF spore community, A-AMF) compared to G. mosseae, which was a dominant morphospecies in the monoculture of native Kummerowia striata. The shift in AMF spore community composition driven by S. canadensis generated functional variation between I-AMF and A-AMF communities. For example, I-AMF increased biomass and nutrient uptake of K. striata in both monocultures and mixtures of K. striata and S. canadensis compared to A-AMF. In contrast, A-AMF significantly enhanced root nitrogen (N) acquisition of S. canadensis grown in mixture. Moreover, mycorrhizal-mediated 15N uptake provided direct evidence that I-AMF and A-AMF differed in their affinities with native and invading species. The non-significant effect of A-AMF on K. striata did not result from allelopathy as root exudates of S. canadensis exhibited positive effects on seed germination and biomass of K. striata under naturally occurring concentrations. When considered together, we found that A-AMF facilitated the invasion of S. canadensis through decreasing competitiveness of the native plant K. striata. The results supported our hypothesis and can be used to improve our understanding of an ecosystem-based perspective towards exotic plant invasion.

  17. Context-dependency of arbuscular mycorrhizal fungi on plant-insect interactions in an agroecosystem

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    Nicholas A Barber

    2013-09-01

    Full Text Available Plants interact with a variety of other community members that have the potential to indirectly influence each other through a shared host plant. Arbuscular mycorrhizal fungi (AMF are generally considered plant mutualists because of their generally positive effects on plant nutrient status and growth. AMF may also have important indirect effects on plants by altering interactions with other community members. By influencing plant traits, AMF can modify aboveground interactions with both mutualists, such as pollinators, and antagonists, such as herbivores. Because herbivory and pollination can dramatically influence plant fitness, comprehensive assessment of plant-AMF interactions should include these indirect effects. To determine how AMF affect plant-insect interactions, we grew Cucumis sativus (Cucurbitaceae under five AMF inoculum treatments and control. We measured plant growth, floral production, flower size, and foliar nutrient content of half the plants, and transferred the other half to a field setting to measure pollinator and herbivore preference of wild insects. Mycorrhizal treatment had no effect on plant biomass or floral traits but significantly affected leaf nutrients, pollinator behavior, and herbivore attack. Although total pollinator visitation did not vary with AMF treatment, pollinators exhibited taxon-specific responses, with honey bees, bumble bees, and Lepidoptera all responding differently to AMF treatments. Flower number and size were unaffected by treatments, suggesting that differences in pollinator preference were driven by other floral traits. Mycorrhizae influenced leaf K and Na, but these differences in leaf nutrients did not correspond to variation in herbivore attack. Overall, we found that AMF indirectly influence both antagonistic and mutualistic insects, but impacts depend on the identity of both the fungal partner and the interacting insect, underscoring the context dependency of plant-AMF interactions.

  18. Medicago truncatula and Glomus intraradices gene expression in cortical cells harboring arbuscules in the arbuscular mycorrhizal symbiosis

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    Tang Yuhong

    2009-01-01

    Full Text Available Abstract Background Most vascular flowering plants have the capacity to form symbiotic associations with arbuscular mycorrhizal (AM fungi. The symbiosis develops in the roots where AM fungi colonize the root cortex and form arbuscules within the cortical cells. Arbuscules are enveloped in a novel plant membrane and their establishment requires the coordinated cellular activities of both symbiotic partners. The arbuscule-cortical cell interface is the primary functional interface of the symbiosis and is of central importance in nutrient exchange. To determine the molecular events the underlie arbuscule development and function, it is first necessary to identify genes that may play a role in this process. Toward this goal we used the Affymetrix GeneChip® Medicago Genome Array to document the M. truncatula transcript profiles associated with AM symbiosis, and then developed laser microdissection (LM of M. truncatula root cortical cells to enable analyses of gene expression in individual cell types by RT-PCR. Results This approach led to the identification of novel M. truncatula and G. intraradices genes expressed in colonized cortical cells and in arbuscules. Within the arbuscule, expression of genes associated with the urea cycle, amino acid biosynthesis and cellular autophagy was detected. Analysis of gene expression in the colonized cortical cell revealed up-regulation of a lysine motif (LysM-receptor like kinase, members of the GRAS transcription factor family and a symbiosis-specific ammonium transporter that is a likely candidate for mediating ammonium transport in the AM symbiosis. Conclusion Transcript profiling using the Affymetrix GeneChip® Medicago Genome Array provided new insights into gene expression in M. truncatula roots during AM symbiosis and revealed the existence of several G. intraradices genes on the M. truncatula GeneChip®. A laser microdissection protocol that incorporates low-melting temperature Steedman's wax, was

  19. Arbuscular mycorrhizal fungi contribute to phosphorus uptake by wheat grown in a phosphorus-fixing soil even in the absence of positive growth responses.

    Science.gov (United States)

    Li, Huiying; Smith, Sally E; Holloway, Robert E; Zhu, Yongguan; Smith, F Andrew

    2006-01-01

    We used 32P to quantify the contribution of an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) to phosphorus (P) uptake by wheat (Triticum aestivum), grown in compartmented pots. The soil was from a major cereal-growing area, the Eyre Peninsula, South Australia; it was highly calcareous and P-fixing. Fertilizer P was added to soil at 20 mg kg(-1), as solid or liquid. Two extraction methods were used to estimate plant-available P. Fungal colonization was well established at harvest (36 d). Application of P decreased both colonization and hyphal length density in soil, with small differences between different P fertilizers. Plants showed large positive responses in terms of growth or total P uptake to all P additions, and showed no positive (or even negative) responses to AM colonization, regardless of P application. 32P was detected only in AM plants, and we calculated that over 50% of P uptake by plants was absorbed via AM fungi, even when P was added. The results add to the growing body of knowledge that 'nonresponsive' AM plants have a functional AM pathway for P transfer to the plant; it should not be ignored in breeding plants for root traits designed to improve P uptake.

  20. The composition of arbuscular mycorrhizal fungal communities differs among the roots, spores and extraradical mycelia associated with five Mediterranean plant species.

    Science.gov (United States)

    Varela-Cervero, Sara; Vasar, Martti; Davison, John; Barea, José Miguel; Öpik, Maarja; Azcón-Aguilar, Concepción

    2015-08-01

    Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF species differ in terms of propagation strategies and the major propagules they form. This study compared the AMF community composition of different propagule fractions - colonized roots, spores and extraradical mycelium (ERM) - associated with five Mediterranean plant species in Sierra de Baza Natural Park (Granada, Spain). AMF were identified using 454 pyrosequencing of the SSU rRNA gene. A total of 96 AMF phylogroups [virtual taxa (VT)] were detected in the study site, including 31 novel VT. After per-sample sequencing depth standardization, 71 VT were recorded from plant roots, and 47 from each of the spore and ERM fractions. AMF communities differed significantly among the propagule fractions, and the root-colonizing fraction differed among host plant species. Indicator VT were detected for the root (13 Glomus VT), spore (Paraglomus VT281, VT336, Pacispora VT284) and ERM (Diversispora VT62) fractions. This study provides detailed evidence from a natural system that AMF taxa are differentially allocated among soil mycelium, soil spores and colonized root propagules. This has important implications for interpreting AMF diversity surveys and designing applications of AMF in vegetation restoration.

  1. Effectiveness of native and exotic arbuscular mycorrhizal fungi on nutrient uptake and ion homeostasis in salt-stressed Cajanus cajan L. (Millsp.) genotypes.

    Science.gov (United States)

    Garg, Neera; Pandey, Rekha

    2015-04-01

    Soil salinity is an increasing problem worldwide, restricting plant growth and production. Research findings show that arbuscular mycorrhizal (AM) fungi have the potential to reduce negative effects of salinity. However, plant growth responses to AM fungi vary as a result of genetic variation in mycorrhizal colonization and plant growth responsiveness. Thus, profitable use of AM requires selection of a suitable combination of host plant and fungal partner. A greenhouse experiment was conducted to compare effectiveness of a native AM fungal inoculum sourced from saline soil and two single exotic isolates, Funneliformis mossseae and Rhizophagus irregularis (single or dual mix), on Cajanus cajan (L.) Millsp. genotypes (Paras and Pusa 2002) under salt stress (0-100 mM NaCl). While salinity reduced plant biomass and disturbed ionic status in both genotypes, Pusa 2002 was more salt tolerant and ensured higher AM fungal colonization, plant biomass and nutrient content with favourable ion status under salinity. Although all AM fungi reduced negative effects of salt stress, R. irregularis (alone or in combination with F. mosseae) displayed highest efficiency under salinity, resulting in highest biomass, yield, nutrient uptake and improved membrane stability with favourable K(+)/Na(+) and Ca(2+)/Na(+) ratios in the host plant. Higher effectiveness of R. irregularis correlated with higher root colonization, indicating that the symbiosis formed by R. irregularis had more stable viability and efficiency under salt stress. These findings enhance understanding of the functional diversity of AM fungi in ameliorating plant salt stress tolerance and suggest the potential use of R. irregularis for increasing Cajanus cajan productivity in saline soils. PMID:25155616

  2. Reforestation of bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with arbuscular mycorrhizal fungi

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    N. Krishnakumar

    2012-11-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted indegradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth.However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum(Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum(Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings of Eucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings of E. tereticornis showed 95% survival over the control seedlings and their growth was also significantlyhigher. Tissue nutrients (N, P, K were also found higher inAM fungi inoculated E. tereticornis than un inoculated control seedlings.

  3. Solanum nigrum grown in contaminated soil: Effect of arbuscular mycorrhizal fungi on zinc accumulation and histolocalisation

    International Nuclear Information System (INIS)

    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. - Zn accumulation by S. nigrum is enhanced by AMF and the metal storage in the tissues at the root level occurs mainly in the cell walls and in the intercellular spaces

  4. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

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    Marjorie Bonareri Oruru

    2016-01-01

    Full Text Available Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers’ needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF, a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility.

  5. Arbuscular Mycorrhizal Fungal Hyphae Alter Soil Bacterial Community and Enhance Polychlorinated Biphenyls Dissipation

    Science.gov (United States)

    Qin, Hua; Brookes, Philip C.; Xu, Jianming

    2016-01-01

    We investigated the role of arbuscular mycorrhizal fungal (AMF) hyphae in alternation of soil microbial community and Aroclor 1242 dissipation. A two-compartment rhizobox system with double nylon meshes in the central was employed to exclude the influence of Cucurbita pepo L. root exudates on hyphal compartment soil. To assess the quantitative effect of AMF hyphae on soil microbial community, we separated the hyphal compartment soil into four horizontal layers from the central mesh to outer wall (e.g., L1–L4). Soil total PCBs dissipation rates ranged from 35.67% of L4 layer to 57.39% of L1 layer in AMF inoculated treatment, which were significant higher than the 17.31% of the control (P biphenyls as well as the total PCBs were significantly correlated with soil hyphal length (P biphenyl dissipation, while taxa from the Oxalobacteraceae and Streptomycetaceae responded negatively to AMF and PCB congener dissipation. Our results suggested that the AMF hyphal exudates as well as the hyphae per se did have quantitative effects on shaping soil microbial community, and could modify the PCBs dissipation processes consequently. PMID:27379068

  6. A dipeptide transporter from the arbuscular mycorrhizal fungus Rhizophagus irregularis is upregulated in the intraradical phase

    Science.gov (United States)

    Belmondo, Simone; Fiorilli, Valentina; Pérez-Tienda, Jacob; Ferrol, Nuria; Marmeisse, Roland; Lanfranco, Luisa

    2014-01-01

    Arbuscular mycorrhizal fungi (AMF), which form an ancient and widespread mutualistic symbiosis with plants, are a crucial but still enigmatic component of the plant micro biome. Nutrient exchange has probably been at the heart of the success of this plant-fungus interaction since the earliest days of plants on land. To characterize genes from the fungal partner involved in nutrient exchange, and presumably important for the functioning of the AM symbiosis, genome-wide transcriptomic data obtained from the AMF Rhizophagus irregularis were exploited. A gene sequence, showing amino acid sequence and transmembrane domains profile similar to members of the PTR2 family of fungal oligopeptide transporters, was identified and called RiPTR2. The functional properties of RiPTR2 were investigated by means of heterologous expression in Saccharomyces cerevisiae mutants defective in either one or both of its di/tripeptide transporter genes PTR2 and DAL5. These assays showed that RiPTR2 can transport dipeptides such as Ala-Leu, Ala-Tyr or Tyr-Ala. From the gene expression analyses it seems that RiPTR2 responds to different environmental clues when the fungus grows inside the root and in the extraradical phase. PMID:25232358

  7. Indigenous arbuscular mycorrhizal fungal assemblages protect grassland host plants from pathogens.

    Directory of Open Access Journals (Sweden)

    Jeannine Wehner

    Full Text Available Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants.We investigated the influence of an interaction between local arbuscular mycorrhizal (AM fungal and pathogenic/saprobic microbial assemblages on the growth of two different plant species from semi-arid grasslands in NE Germany (Mallnow near Berlin. In a greenhouse experiment each plant species was grown for six months in either sterile soil or in sterile soil with one of three different treatments: 1 an AM fungal spore fraction isolated from field soil from Mallnow; 2 a soil pathogen/saprobe fraction consisting of a microbial community prepared with field soil from Mallnow and; 3 the combined AM fungal and pathogen/saprobe fractions. While both plant species grew significantly larger in the presence of AM fungi, they responded negatively to the pathogen/saprobe treatment. For both plant species, we found evidence of pathogen protection effects provided by the AM fungal assemblages. These results indicate that interactions between assemblages of beneficial and pathogenic microorganisms can influence the growth of host plants, but that the magnitude of these effects is plant species-specific.

  8. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems.

    Science.gov (United States)

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  9. Indigenous arbuscular mycorrhizal fungal assemblages protect grassland host plants from pathogens.

    Science.gov (United States)

    Wehner, Jeannine; Antunes, Pedro M; Powell, Jeff R; Caruso, Tancredi; Rillig, Matthias C

    2011-01-01

    Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants.We investigated the influence of an interaction between local arbuscular mycorrhizal (AM) fungal and pathogenic/saprobic microbial assemblages on the growth of two different plant species from semi-arid grasslands in NE Germany (Mallnow near Berlin). In a greenhouse experiment each plant species was grown for six months in either sterile soil or in sterile soil with one of three different treatments: 1) an AM fungal spore fraction isolated from field soil from Mallnow; 2) a soil pathogen/saprobe fraction consisting of a microbial community prepared with field soil from Mallnow and; 3) the combined AM fungal and pathogen/saprobe fractions. While both plant species grew significantly larger in the presence of AM fungi, they responded negatively to the pathogen/saprobe treatment. For both plant species, we found evidence of pathogen protection effects provided by the AM fungal assemblages. These results indicate that interactions between assemblages of beneficial and pathogenic microorganisms can influence the growth of host plants, but that the magnitude of these effects is plant species-specific. PMID:22110635

  10. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

    Science.gov (United States)

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  11. A plausible mechanism of biosorption in dual symbioses by vesicular-arbuscular mycorrhizal in plants.

    Science.gov (United States)

    Azmat, Rafia; Hamid, Neelofer

    2015-03-01

    Dual symbioses of vesicular-arbuscular mycorrhizal (VAM) fungi with growth of Momordica charantia were elucidated in terms of plausible mechanism of biosorption in this article. The experiment was conducted in green house and mixed inoculum of the VAM fungi was used in the three replicates. Results demonstrated that the starch contents were the main source of C for the VAM to builds their hyphae. The increased plant height and leaves surface area were explained in relation with an increase in the photosynthetic rates to produce rapid sugar contents for the survival of plants. A decreased in protein, and amino acid contents and increased proline and protease activity in VAM plants suggested that these contents were the main bio-indicators of the plants under biotic stress. The decline in protein may be due to the degradation of these contents, which later on converted into dextrose where it can easily be absorbed by for the period of symbioses. A mechanism of C chemisorption in relation with physiology and morphology of plant was discussed.

  12. Interaction of Vesicular-Arbuscular Mycorrhizal Fungi with Erosion in an Oxisol †

    Science.gov (United States)

    Habte, M.; Fox, R. L.; Aziz, T.; El-Swaify, S. A.

    1988-01-01

    The development of vesicular-arbuscular mycorrhizal (VAM) symbiosis was monitored in Leucaena leucocephala grown in an Oxisol subjected to incremental simulated erosion. The density of VAM infective propagules in the soil diminished as the level of simulated erosion (removal of surface soil) was increased from 0 to 50 cm. The level of infection on L. leucocephala roots observed at harvest was not significantly influenced by simulated erosion unless removal of surface soil exceeded 25 cm. Inoculation of this soil and the uneroded soil with Glomus aggregatum enhanced the early onset of infection but did not significantly influence the level of infection observed at the time of harvest. Simulated erosion in excess of 7.5 cm of surface soil removal significantly delayed the development of VAM effectiveness monitored in terms of the P status of L. leucocephala subleaflets and also curtailed the level of maximum effectiveness observed. Decreases in VAM effectiveness were significantly correlated with decreases in soil chemical constituents. However, VAM effectiveness in a soil subjected to 30 cm of surface soil removal was not restored to a significant extent unless the soil was amended with P, even though other nutrients were restored to sufficiency levels. Our results demonstrate that the development of VAM effectiveness is the phase of the VAM symbiosis that is most adversely influenced by simulated erosion and that this effect appears to be caused primarily by insufficient P in the soil solution. PMID:16347615

  13. Arbuscular mycorrhizal fungal networks vary throughout the growing season and between successional stages.

    Directory of Open Access Journals (Sweden)

    Alison Elizabeth Bennett

    Full Text Available To date, few analyses of mutualistic networks have investigated successional or seasonal dynamics. Combining interaction data from multiple time points likely creates an inaccurate picture of the structure of networks (because these networks are aggregated across time, which may negatively influence their application in ecosystem assessments and conservation. Using a replicated bipartite mutualistic network of arbuscular mycorrhizal (AM fungal-plant associations, detected using large sample numbers of plants and AM fungi identified through molecular techniques, we test whether the properties of the network are temporally dynamic either between different successional stages or within the growing season. These questions have never been directly tested in the AM fungal-plant mutualism or the vast majority of other mutualisms. We demonstrate the following results: First, our examination of two different successional stages (young and old forest demonstrated that succession increases the proportion of specialists within the community and decreases the number of interactions. Second, AM fungal-plant mutualism structure changed throughout the growing season as the number of links between partners increased. Third, we observed shifts in associations between AM fungal and plant species throughout the growing season, potentially reflecting changes in biotic and abiotic conditions. Thus, this analysis opens up two entirely new areas of research: 1 identifying what influences changes in plant-AM fungal associations in these networks, and 2 what aspects of temporal variation and succession are of general importance in structuring bipartite networks and plant-AM fungal communities.

  14. Biases for detecting arbuscular mycorrhizal fungal mixture by terminal restriction fragment length polymorphism (T-RFLP).

    Science.gov (United States)

    Watanarojanaporn, N; Longtonglang, A; Boonkerd, N; Tittabutr, P; Lee, J; Teaumroong, N

    2014-01-01

    Terminal restriction fragment length polymorphism (T-RFLP) analysis of amplified ribosomal RNA genes is used for profiling microbial communities and sometimes for species richness and relative abundance estimation in environmental samples. However, the T-RFLP fingerprint may be subject to biases during the procedure, influencing the detection of real community structures in the environment. To investigate possible sources of T-RFLP bias, 18S rRNA gene clones derived from two arbuscular mycorrhizal fungal sequences were combined in simple pairwise mixes to assess the effects of polymerase chain reaction cycle number, plant genomic DNA purification method and varying template ratio on the template-to-product ratio as measured by relative T-RF peak area. Varying cycle numbers indicated that amplification was still in the exponential phase at the cycle numbers lower than 18, so these small cycle numbers were used for the comparison of template-to-product quantities. Relative abundance estimated from T-RF peak ratios varied with different purification procedures, but the best results, closest to input ratios, were obtained by using phenol-chloroform purification. The presence of an excess of unpurified non-target plant genomic DNA generated a bias towards lower or overestimation of relative abundance. We conclude that a low number of amplification cycles and stringent DNA purification are necessary for accurate mixed sample analysis by T-RFLP.

  15. Recombination in Glomus intraradices, a supposed ancient asexual arbuscular mycorrhizal fungus

    Directory of Open Access Journals (Sweden)

    Sanders Ian R

    2009-01-01

    Full Text Available Abstract Background Arbuscular mycorrhizal fungi (AMF are important symbionts of most plant species, promoting plant diversity and productivity. This symbiosis is thought to have contributed to the early colonisation of land by plants. Morphological stasis over 400 million years and the lack of an observed sexual stage in any member of the phylum Glomeromycota led to the controversial suggestion of AMF being ancients asexuals. Evidence for recombination in AMF is contradictory. Results We addressed the question of recombination in the AMF Glomus intraradices by sequencing 11 polymorphic nuclear loci in 40 morphologically identical isolates from one field. Phylogenetic relationships among genotypes showed a reticulate network pattern providing a rationale to test for recombination. Five statistical tests predicted multiple recombinant regions in the genome of a core set of isolates. In contrast, five clonal lineages had fixed a large number of differences. Conclusion Our data show that AMF from one field have undergone recombination but that clonal lineages coexist. This finding has important consequences for understanding AMF evolution, co-evolution of AMF and plants and highlights the potential for commercially introduced AMF inoculum recombining with existing local populations. Finally, our results reconcile seemingly contradictory studies on whether AMF are clonal or form recombining populations.

  16. Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis.

    Science.gov (United States)

    Tisserant, Emilie; Malbreil, Mathilde; Kuo, Alan; Kohler, Annegret; Symeonidi, Aikaterini; Balestrini, Raffaella; Charron, Philippe; Duensing, Nina; Frei dit Frey, Nicolas; Gianinazzi-Pearson, Vivienne; Gilbert, Luz B; Handa, Yoshihiro; Herr, Joshua R; Hijri, Mohamed; Koul, Raman; Kawaguchi, Masayoshi; Krajinski, Franziska; Lammers, Peter J; Masclaux, Frederic G; Murat, Claude; Morin, Emmanuelle; Ndikumana, Steve; Pagni, Marco; Petitpierre, Denis; Requena, Natalia; Rosikiewicz, Pawel; Riley, Rohan; Saito, Katsuharu; San Clemente, Hélène; Shapiro, Harris; van Tuinen, Diederik; Bécard, Guillaume; Bonfante, Paola; Paszkowski, Uta; Shachar-Hill, Yair Y; Tuskan, Gerald A; Young, J Peter W; Young, Peter W; Sanders, Ian R; Henrissat, Bernard; Rensing, Stefan A; Grigoriev, Igor V; Corradi, Nicolas; Roux, Christophe; Martin, Francis

    2013-12-10

    The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned. Here we introduce the 153-Mb haploid genome of Rhizophagus irregularis and its repertoire of 28,232 genes. The observed low level of genome polymorphism (0.43 SNP per kb) is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall-degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues. The present comprehensive repertoire of R. irregularis genes provides a basis for future research on symbiosis-related mechanisms in Glomeromycota.

  17. A history of the taxonomy and systematics of arbuscular mycorrhizal fungi belonging to the phylum Glomeromycota.

    Science.gov (United States)

    Stürmer, Sidney Luiz

    2012-05-01

    Arbuscular mycorrhizal fungi (AMF) are grouped in a monophyletic group, the phylum Glomeromycota. In this review, the history and complexity of the taxonomy and systematics of these obligate biotrophs is addressed by recognizing four periods. The initial discovery period (1845-1974) is characterized by description mainly of sporocarp-forming species and the proposal of a classification for these fungi. The following alpha taxonomy period (1975-1989) established a solid morphological basis for species identification and classification, resulting in a profuse description of new species and a need to standardize the nomenclature of spore subcellular structures. The cladistics period from 1990 to 2000 saw the first cladistic classification of AMF based on phenotypic characters only. At the end of this period, genetic characters played a role in defining taxa and elucidating evolutionary relationships within the group. The most recent phylogenetic synthesis period (2001 to present) started with the proposal of a new classification based on genetic characters using sequences of the multicopy rRNA genes.

  18. Role of Dual Inoculation of Rhizobium and Arbuscular Mycorrhizal (AM Fungi on Pulse Crops Production

    Directory of Open Access Journals (Sweden)

    Erneste HAVUGIMANA

    2016-01-01

    Full Text Available Legume crops are useful as human and animal feed, wood energy, and as soil-improving components of agricultural and agro forestry systems through its association with bio-fertilizers. The later have a potential environment friendly inputs that are supplemented for proper plant growth. Bio-fertilizers are preparations containing living cells of microorganisms that help crop plants in the uptake of nutrients by their interactions in the rhizosphere. Arbuscular mycorrhizal (AM fungi are beneficial symbionts for plant growth. They are associated with higher plants by a symbiotic association and benefit plants in the uptake of phosphorus nutrients, production of growth hormones, increase of proteins, lipids and sugars levels, helps in heavy metal binding, salinity tolerance and disease resistance. In nature symbiotic association of Rhizobium and leguminous plants fixes atmospheric nitrogen. Indeed, research has proved that the association of mycorrhizae fungi and Rhizobium, with pulse crops, increased the beneficial aspects comparatively more than their single associations with the host plants. This review focuses on the role of dual inoculation of AM fungi and Rhizobium on different pulse crops.

  19. Diversity of arbuscular mycorrhizal fungus populations in heavy-metal-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Del Val, C.; Barea, J.M.; Azcon-Aguilar, C. [CSIC, Granada (Spain)

    1999-02-01

    High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil. The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment. Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi. Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals. AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil. Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil. However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge. Relative densities of most AMF species were also significantly influenced by soil treatments. Host plant species exerted a selective influence on AMF population size and diversity. The authors conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils.

  20. Precipitation shapes communities of arbuscular mycorrhizal fungi in Tibetan alpine steppe.

    Science.gov (United States)

    Zhang, Jing; Wang, Fang; Che, Rongxiao; Wang, Ping; Liu, Hanke; Ji, Baoming; Cui, Xiaoyong

    2016-01-01

    Tibetan Plateau is one of the largest and most unique habitats for organisms including arbuscular mycorrhizal fungi (AMF). However, it remains unclear how AMF communities respond to key environmental changes in this harsh environment. To test if precipitation could be a driving force in shaping AMF community structures at regional scale, we examined AMF communities associated with dominant plant species along a precipitation gradient in Tibetan alpine steppe. Rhizosphere soils were collected from five sites with annual precipitation decreasing from 400 to 50 mm. A total of 31 AMF operational taxonomic units (OTUs) were identified. AMF community composition varied significantly among sites, whereas AMF community composition did not vary among plant species. Path analysis revealed that precipitation directly affected AMF hyphal length density, and indirectly influenced AMF species richness likely through the mediation of plant coverage. Our results suggested that water availability could drive the changes of AMF communities at regional scale. Given the important roles AMF could play in the dynamics of plant communities, exploring the changes of AMF communities along key environmental gradients would help us better predict the ecosystem level responses of the Tibetan vegetation to future climate change. PMID:27002188

  1. Development of Soils and Communities of Plants and Arbuscular Mycorrhizal Fungi on West Virginia Surface Mines

    Science.gov (United States)

    Levy, Michael A.; Cumming, Jonathan R.

    2014-11-01

    Surface mining followed by reclamation to pasture is a major driver of land use and cover change in Appalachia. Prior research suggests that many aspects of ecosystem recovery are either slow or incomplete. We examined ecosystem structure—including soil physical and chemical properties, arbuscular mycorrhizal fungal (AMF) infectivity and community composition, and plant diversity and community composition—on a chronosequence of pasture-reclaimed surface mines and a non-mined pasture in northern West Virginia. Surface mining and reclamation dramatically altered ecosystem structure. Some aspects of ecosystem structure, including many measures of soil chemistry and infectivity of AMF, returned rapidly to levels found on the non-mined reference site. Other aspects of ecosystem structure, notably soil physical properties and AMF and plant communities, showed incomplete or no recovery over the short-to-medium term. In addition, invasive plants were prevalent on reclaimed mine sites. The results point to the need for investigation on how reclamation practices could minimize establishment of exotic invasive plant species and reduce the long-term impacts of mining on ecosystem structure and function.

  2. Genetic Diversity and Association Characters of Bacteria Isolated from Arbuscular Mycorrhizal Fungal Spore Walls.

    Science.gov (United States)

    Selvakumar, Gopal; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sa, Tong-Min

    2016-01-01

    Association between arbuscular mycorrhizal fungi (AMF) and bacteria has long been studied. However, the factors influencing their association in the natural environment is still unknown. This study aimed to isolate bacteria associated with spore walls of AMF and identify their potential characters for association. Spores collected from coastal reclamation land were differentiated based on their morphology and identified by 18S rDNA sequencing as Funneliformis caledonium, Racocetra alborosea and Funneliformis mosseae. Bacteria associated with AMF spore walls were isolated after treating them with disinfection solution at different time intervals. After 0, 10 and 20 min of spore disinfection, 86, 24 and 10 spore associated bacteria (SAB) were isolated, respectively. BOX-PCR fingerprinting analysis showed that diverse bacterial communities were associated to AMF spores. Bacteria belonging to the same genera could associate with different AMF spores. Gram positive bacteria were more closely associated with AMF spores. Isolated SAB were characterized and tested for spore association characters such as chitinase, protease, cellulase enzymes and exopolysaccharide production (EPS). Among the 120 SAB, 113 SAB were able to show one or more characters for association and seven SAB did not show any association characters. The 16S rDNA sequence of SAB revealed that bacteria belonging to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bactereiodes were associated with AMF spore walls. PMID:27479250

  3. Spatio-Temporal Variation of Core and Satellite Arbuscular Mycorrhizal Fungus Communities in Miscanthus giganteus.

    Science.gov (United States)

    Barnes, Christopher J; Burns, Caitlin A; van der Gast, Christopher J; McNamara, Niall P; Bending, Gary D

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are a group of obligate plant symbionts which can promote plant nutrition. AMF communities are diverse, but the factors which control their assembly in space and time remain unclear. In this study, the contributions of geographical distance, environmental heterogeneity and time in shaping AMF communities associated with Miscanthus giganteus (a perennial grass originating from south-east Asia) were determined over a 13 months period. In particular, the community was partitioned into core (abundant and persistent taxa) and satellite (taxa with low abundance and persistence) constituents and the drivers of community assembly for each determined. β-diversity was exceptionally low across the 140 m line transects, and there was limited evidence of geographical scaling effects on the composition of the core, satellite or combined communities. However, AMF richness and community composition changed over time associated with fluctuation within both the core and satellite communities. The degree to which AMF community variation was explained by soil properties was consistently higher in the core community than the combined and satellite communities, suggesting that the satellite community had considerable stochasticity associated with it. We suggest that the partitioning of communities into their core and satellite constituents could be employed to enhance the variation explained within microbial community analyses. PMID:27597844

  4. Reducing nitrogen runoff from paddy fields with arbuscular mycorrhizal fungi under different fertilizer regimes.

    Science.gov (United States)

    Zhang, Shujuan; Wang, Li; Ma, Fang; Zhang, Xue; Fu, Dafang

    2016-08-01

    Nitrogen (N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi (AMF). In northeast China, Shuangcheng city in Heilongjiang province, a field experiment was conducted, using rice provided with 0%, 20%, 40%, 60%, 80%, and 100% of the local norm of fertilization (including N, phosphorus and potassium), with or without inoculation with Glomus mosseae. The volume, concentrations of total N (TN), dissolved N (DN) and particulate N (PN) of runoff water were measured. We found that the local norm of fertilization led to 18.9kg/ha of N runoff during rice growing season, with DN accounting for 60%-70%. We also found that reduction in fertilization by 20% cut down TN runoff by 8.2% while AMF inoculation decreased N runoff at each fertilizer level and this effect was inhibited by high fertilization. The combination of inoculation with AMF and 80% of the local norm of fertilization was observed to reduce N runoff by 27.2%. Conclusively, we suggested that the contribution of AMF inoculation combined with decreasing fertilization should get more attention to slow down water eutrophication by reducing N runoff from paddy fields. PMID:27521940

  5. Solanum nigrum grown in contaminated soil: Effect of arbuscular mycorrhizal fungi on zinc accumulation and histolocalisation

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Ana P.G.C. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: amarques@mail.esb.ucp.pt; Oliveira, Rui S. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: rsoliveira@mail.esb.ucp.pt; Samardjieva, Kalina A. [Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal)]. E-mail: kas@ibmc.up.pt; Pissarra, Jose [Faculdade de Ciencias da Universidade do Porto, Departamento de Botanica, Rua do Campo Alegre, 1191, 4150-181 Porto (Portugal)]. E-mail: jpissarr@fc.up.pt; Rangel, Antonio O.S.S. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: arangel@esb.ucp.pt; Castro, Paula M.L. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)]. E-mail: plcastro@esb.ucp.pt

    2007-02-15

    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{sup -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. - Zn accumulation by S. nigrum is enhanced by AMF and the metal storage in the tissues at the root level occurs mainly in the cell walls and in the intercellular spaces.

  6. Bioremediation of adverse impact of cadmium toxicity on Cassia italica Mill by arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Egamberdieva, Dilfuza

    2016-01-01

    Cassia italica Mill is an important medicinal plant within the family Fabaceae. Pot experiment was conducted to evaluate cadmium stress induced changes in physiological and biochemical attributes in C. italica with and without arbuscular mycorrhizal fungi (AMF). Cadmium stressed plant showed reduced chlorophyll pigment and protein content while AMF inoculation enhanced the chlorophyll and protein content considerably. AMF also ameliorated the cadmium stress induced reduction in total chlorophyll and protein contents by 19.30% and 38.29%, respectively. Cadmium stress enhanced lipid peroxidation while AMF inoculation reduced lipid peroxidation considerably. Increase in proline and phenol content was observed due to cadmium stress and AMF inoculation caused a further increase in proline and phenol content ensuring better growth under stressed conditions. AMF alone also enhanced proline and phenol content. Activity of antioxidant enzymes enhanced under cadmium treatment and AMF inoculation further enhanced their activity thereby strengthening the antioxidant system. Enhanced activities of antioxidants and increased accumulation of osmolytes help plants to avoid damaging impact of oxidative damage. The research has shown that AMF inoculation mitigated the negative impact of stress by reducing the lipid peroxidation and enhancing the antioxidant activity. The present study strongly supports employing AMF as the biological mean for enhancing the cadmium stress tolerance of C. italica. PMID:26858537

  7. Molecular diversity of arbuscular mycorrhizal fungi in relation to soil chemical properties and heavy metal contamination

    Energy Technology Data Exchange (ETDEWEB)

    Zarei, Mehdi [Department of Soil Science, College of Agriculture, University of Shiraz, Shiraz (Iran, Islamic Republic of); Hempel, Stefan, E-mail: hempel.stefan@googlemail.co [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Freie Universitaet Berlin, Institut fuer Biologie, Okologie der Pflanzen, Altensteinstrasse 6, 14195 Berlin (Germany); Wubet, Tesfaye; Schaefer, Tina [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany); Savaghebi, Gholamreza [Department of Soil Science Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj (Iran, Islamic Republic of); Jouzani, Gholamreza Salehi; Nekouei, Mojtaba Khayam [Agricultural Biotechnology Research Institute of Iran (ABRII), P.O. Box 31535-1897, Karaj (Iran, Islamic Republic of); Buscot, Francois [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Soil Ecology, Theodor-Lieser-Strasse 4, 06120 Halle (Germany)

    2010-08-15

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) associated with dominant plant species were studied along a transect from highly lead (Pb) and zinc (Zn) polluted to non-polluted soil at the Anguran open pit mine in Iran. Using an established primer set for AMF in the internal transcribed spacer (ITS) region of rDNA, nine different AMF sequence types were distinguished after phylogenetic analyses, showing remarkable differences in their distribution patterns along the transect. With decreasing Pb and Zn concentration, the number of AMF sequence types increased, however one sequence type was only found in the highly contaminated area. Multivariate statistical analysis revealed that further factors than HM soil concentration affect the AMF community at contaminated sites. Specifically, the soils' calcium carbonate equivalent and available P proved to be of importance, which illustrates that field studies on AMF distribution should also consider important environmental factors and their possible interactions. - The molecular diversity of AMF was found to be influenced by a combination of soil heavy metal and other soil chemical parameters.

  8. Influence of Arbuscular Mycorrhizal Fungus (AMF) on degradation of iron-cyanide complexes

    Science.gov (United States)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2015-04-01

    Soil contamination in the vicinities of former Manufactured Gas Plant (MGP) sites is a worldwide known environmental issue. The pollutants, in form of iron-cyanide complexes, originating from the gas purification process, create a risk for human health due to potential release of toxic free cyanide, CN(aq) and HCN(g), (aq).The management and remediation of cyanide contaminated soil can be very challenging due to the complex chemistry and toxicity of CN compounds. The employment of phytoremediation to remove or stabilize contaminants at a former MGP site is an inexpensive process, but can be limited through shallow rotting, decreased biomass, poor growing and the risk of secondary accumulation. However, this adaptation may be enhanced via arbuscular mycorrhizal fungi (AMF) activity, which may cooperate on the degradation, transformation or uptake of the contaminants. We would like to present our preliminary results from the ongoing project concerning toxic substrate-AMF-plant relation, based on studying the site of a former MGP site. In situ experiments contributed to identifying those fungi that are likely to persist in extremely acidic and toxic conditions. Subsequently, commercially available Rhizophagus irregularis was grown in sterilized, un-spiked soil with the roots of the host plant Calamagrostis epigejos. Extracted roots and AMF hyphae were used in the batch experiment, were the potential of this association on degradation of iron-cyanide complexes, in form of potassium ferrocyanide solution, was assessed.

  9. Evidence for the sexual origin of heterokaryosis in arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Ropars, Jeanne; Toro, Kinga Sędzielewska; Noel, Jessica; Pelin, Adrian; Charron, Philippe; Farinelli, Laurent; Marton, Timea; Krüger, Manuela; Fuchs, Jörg; Brachmann, Andreas; Corradi, Nicolas

    2016-01-01

    Sexual reproduction is ubiquitous among eukaryotes, and fully asexual lineages are extremely rare. Prominent among ancient asexual lineages are the arbuscular mycorrhizal fungi (AMF), a group of plant symbionts with a multinucleate cytoplasm. Genomic divergence among co-existing nuclei was proposed to drive the evolutionary success of AMF in the absence of sex(1), but this hypothesis has been contradicted by recent genome analyses that failed to find significant genetic diversity within an AMF isolate(2,3). Here, we set out to resolve issues surrounding the genome organization and sexual potential of AMF by exploring the genomes of five isolates of Rhizophagus irregularis, a model AMF. We find that genetic diversity in this species varies among isolates and is structured in a homo-dikaryon-like manner usually linked with the existence of a sexual life cycle. We also identify a putative AMF mating-type locus, containing two genes with structural and evolutionary similarities with the mating-type locus of some Dikarya. Our analyses suggest that this locus may be multi-allelic and that AMF could be heterothallic and bipolar. These findings reconcile opposing views on the genome organization of these ubiquitous plant symbionts and open avenues for strain improvement and environmental application of these organisms. PMID:27572831

  10. Plant Identity Exerts Stronger Effect than Fertilization on Soil Arbuscular Mycorrhizal Fungi in a Sown Pasture.

    Science.gov (United States)

    Zheng, Yong; Chen, Liang; Luo, Cai-Yun; Zhang, Zhen-Hua; Wang, Shi-Ping; Guo, Liang-Dong

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi play key roles in plant nutrition and plant productivity. AM fungal responses to either plant identity or fertilization have been investigated. However, the interactive effects of different plant species and fertilizer types on these symbiotic fungi remain poorly understood. We evaluated the effects of the factorial combinations of plant identity (grasses Avena sativa and Elymus nutans and legume Vicia sativa) and fertilization (urea and sheep manure) on AM fungi following 2-year monocultures in a sown pasture field study. AM fungal extraradical hyphal density was significantly higher in E. nutans than that in A. sativa and V. sativa in the unfertilized control and was significantly increased by urea and manure in A. sativa and by manure only in E. nutans, but not by either fertilizers in V. sativa. AM fungal spore density was not significantly affected by plant identity or fertilization. Forty-eight operational taxonomic units (OTUs) of AM fungi were obtained through 454 pyrosequencing of 18S rDNA. The OTU richness and Shannon diversity index of AM fungi were significantly higher in E. nutans than those in V. sativa and/or A. sativa, but not significantly affected by any fertilizer in all of the three plant species. AM fungal community composition was significantly structured directly by plant identity only and indirectly by both urea addition and plant identity through soil total nitrogen content. Our findings highlight that plant identity has stronger influence than fertilization on belowground AM fungal community in this converted pastureland from an alpine meadow.

  11. Impact of alien pines on local arbuscular mycorrhizal fungal communities-evidence from two continents.

    Science.gov (United States)

    Gazol, Antonio; Zobel, Martin; Cantero, Juan José; Davison, John; Esler, Karen J; Jairus, Teele; Öpik, Maarja; Vasar, Martti; Moora, Mari

    2016-06-01

    The introduction of alien plants can influence biodiversity and ecosystems. However, its consequences for soil microbial communities remain poorly understood. We addressed the impact of alien ectomycorrhizal (EcM) pines on local arbuscular mycorrhizal (AM) fungal communities in two regions with contrasting biogeographic histories: in South Africa, where no native EcM plant species are present; and in Argentina, where EcM trees occur naturally. The effect of alien pines on AM fungal communities differed between these regions. In South Africa, plantations of alien EcM pines exhibited lower AM fungal richness and significantly altered community composition, compared with native fynbos. In Argentina, the richness and composition of local AM fungal communities were similar in plantations of alien EcM pines and native forest. However, the presence of alien pines resulted in slight changes to the phylogenetic structure of root AM fungal communities in both regions. In pine clearcut areas in South Africa, the richness and composition of AM fungal communities were intermediate between the native fynbos and the alien pine plantation, which is consistent with natural regeneration of former AM fungal communities following pine removal. We conclude that the response of local AM fungal communities to alien EcM pines differs between biogeographic regions with different histories of species coexistence. PMID:27056916

  12. Relative Importance of Individual Climatic Drivers Shaping Arbuscular Mycorrhizal Fungal Communities.

    Science.gov (United States)

    Xiang, Dan; Veresoglou, Stavros D; Rillig, Matthias C; Xu, Tianle; Li, Huan; Hao, Zhipeng; Chen, Baodong

    2016-08-01

    The physiological tolerance hypothesis (PTH) postulates that it is the tolerance of species to climatic factors that determines overall community richness. Here, we tested whether a group of mutualistic microbes, Glomeromycota, is distributed in semi-arid environments in ways congruent with the PTH. For this purpose, we modeled with climatic predictors the niche of each of the four orders of Glomeromycota and identified predictors of arbuscular mycorrhizal (AM) fungal operational taxonomic unit (OTU) richness. Our dataset consisted of 50 paired grassland and farmland sites in the farming-pastoral ecotone of northern China. We observed shifts in the relative abundance of AM fungal orders in response to climatic variables but also declines in OTU richness in grassland sites that had experienced high precipitation during the preceding year which was incongruous with the PTH. We found pronounced differences across groups of Glomeromycotan fungi in their responses to climatic variables and identified strong dependencies of AM fungal communities on precipitation. Given that precipitation is expected to further decline in the farming-pastoral ecotone over the coming years and that mycorrhiza represents an integral constituent of ecosystem functioning, it is likely that the ecosystem services in the region will change accordingly. PMID:27117797

  13. Nutritional effects of indigenous arbuscular mycorrhizal associations on the sclerophyllous species Agathosma betulina

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    M. A. Pèrez-Fernández

    2007-09-01

    Full Text Available Relatively little is currently known about the seedling physiology of arbuscular mycorrhizal (AM Agathosma betulina, a sclerophyllous crop plant cultivated for its high-value essential oils and food additives. In addition, virtually nothing is known about the AM associations of this plant. Consequently, the effect of an indigenous community of AM fungi on P nutrition and C economy in seedlings, grown in nursery conditions, was determined during different stages of host and AM fungal establishment. AM fungal ribosomal gene sequence analyses were used to identify some of the fungi within the roots, responsible for the nutritional changes. During the early stages of host and AM fungal establishment (0 to 77 days after germination, host growth was reduced, whereas the rate of P-uptake and growth respiration was increased. Beyond 77 days of growth, the rate of P-uptake and growth respiration declined. These findings, together with results obtained after molecular analyses of root associated fungal DNA, indicate that AM fungi belonging to the genera Acaulospora and Glomus, improve P-uptake and costs of utilization during the early stages of seedling establishment in a nutrient-poor soil.

  14. Diversity of Arbuscular Mycorrhizal Fungi in a Brazilian Atlantic Forest Toposequence.

    Science.gov (United States)

    Bonfim, Joice Andrade; Vasconcellos, Rafael Leandro Figueiredo; Gumiere, Thiago; de Lourdes Colombo Mescolotti, Denise; Oehl, Fritz; Nogueira Cardoso, Elke Jurandy Bran

    2016-01-01

    The diversity of arbuscular mycorrhizal fungi (AMF) was studied in the Atlantic Forest in Serra do Mar Park (SE Brazil), based on seven host plants in relationship to their soil environment, altitude and seasonality. The studied plots along an elevation gradient are located at 80, 600, and 1,000 m. Soil samples (0-20 cm) were collected in four seasons from SE Brazilian winter 2012 to autumn 2013. AMF spores in rhizosperic soils were morphologically classified and chemical, physical and microbiological soil caracteristics were determined. AMF diversity in roots was evaluated using the NS31/AM1 primer pair, with subsequent cloning and sequencing. In the rhizosphere, 58 AMF species were identified. The genera Acaulospora and Glomus were predominant. However, in the roots, only 14 AMF sequencing groups were found and all had high similarity to Glomeraceae. AMF species identities varied between altitudes and seasons. There were species that contributed the most to this variation. Some soil characteristics (pH, organic matter, microbial activity and microbial biomass carbon) showed a strong relationship with the occurrence of certain species. The highest AMF species diversity, based on Shannon's diversity index, was found for the highest altitude. Seasonality did not affect the diversity. Our results show a high AMF diversity, higher than commonly found in the Atlantic Forest. The AMF detected in roots were not identical to those detected in rhizosperic soil and differences in AMF communities were found in different altitudes even in geographically close-lying sites. PMID:26304552

  15. Arbuscular mycorrhizal fungi: new species and records in Northeast of Brazil

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    Danielle Karla Alves da Silva

    2014-10-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF comprise the largest association of plants and fungi in nature yet have only recently been considered within the context of conservation biology. The aim of this work was to document the occurrence of AMF species and highlight recent advances in our knowledge of their diversity in Northeast Brazil. This new information has been generated by the Sisbiota-Brazil Program (National System of Biodiversity Research and provides the basis for a discussion on the AMF species found in the region. The work included a bibliographic review of the records from natural and agricultural area plus data generated by collections made in natural areas in six of the nine northeastern states during the period 2010-2013. Overall we recorded 28 genera and 125 species of AMF. Of these, 11 were new species, 13 represented new records for Brazil and six were unique to the Northeast. This represents a 25% increase in our knowledge of the diversity of AMF in the region. We can now estimate that the Northeast represents about 50% of the AMF species described worldwide. This finding reinforces the need for more studies in areas that are poorly studied in order to extend our understanding of this biodiversity and to help to define future strategies for management and conservation.

  16. A plausible mechanism of biosorption in dual symbioses by vesicular-arbuscular mycorrhizal in plants.

    Science.gov (United States)

    Azmat, Rafia; Hamid, Neelofer

    2015-03-01

    Dual symbioses of vesicular-arbuscular mycorrhizal (VAM) fungi with growth of Momordica charantia were elucidated in terms of plausible mechanism of biosorption in this article. The experiment was conducted in green house and mixed inoculum of the VAM fungi was used in the three replicates. Results demonstrated that the starch contents were the main source of C for the VAM to builds their hyphae. The increased plant height and leaves surface area were explained in relation with an increase in the photosynthetic rates to produce rapid sugar contents for the survival of plants. A decreased in protein, and amino acid contents and increased proline and protease activity in VAM plants suggested that these contents were the main bio-indicators of the plants under biotic stress. The decline in protein may be due to the degradation of these contents, which later on converted into dextrose where it can easily be absorbed by for the period of symbioses. A mechanism of C chemisorption in relation with physiology and morphology of plant was discussed. PMID:25730809

  17. Arbuscular mycorrhizal fungi in a semiarid copper mining area in Brazil.

    Science.gov (United States)

    da Silva, Gladstone Alves; Trufem, Sandra Farto Botelho; Saggin Júnior, Orivaldo José; Maia, Leonor Costa

    2005-01-01

    The occurrence of arbuscular mycorrhizal fungi (AMF) in a copper mining area was investigated. Soil samples were collected from six sites at the Mineração Caraiba, Bahia State, northeastern Brazil, comprising: (1) a site that receives the waste product; (2) a site that receives low grade deposits; (3) the interface between the caatinga and site 1; (4) the surroundings of the industrial area; (5) the site for extracting topsoil for land filling; (6) the preserved caatinga. Thirty-two plant species were identified around the collection locations. Trap cultures were maintained in the greenhouse for 3 months, using bahia grass ( Paspalum notatum Flügge) as the host plant. Spores were extracted from soil and 21 AMF species (15 Glomus and one of each of Acaulospora, Archaeospora, Entrophospora, Gigaspora , Paraglomus and Scutellospora) were identified. In site 1, plants or AMF were not found during the dry season. Site 6, with native vegetation, had the highest number of plants and AMF species. The disturbed sites showed less plant diversification, with the community of AMF being quantitative and qualitatively affected by disturbance. PMID:14767726

  18. Relative importance of an arbuscular mycorrhizal fungus (Rhizophagus intraradices) and root hairs in plant drought tolerance.

    Science.gov (United States)

    Li, Tao; Lin, Ge; Zhang, Xin; Chen, Yongliang; Zhang, Shubin; Chen, Baodong

    2014-11-01

    Both arbuscular mycorrhizal (AM) fungi and root hairs play important roles in plant uptake of water and mineral nutrients. To reveal the relative importance of mycorrhiza and root hairs in plant water relations, a bald root barley (brb) mutant and its wild type (wt) were grown with or without inoculation of the AM fungus Rhizophagus intraradices under well-watered or drought conditions, and plant physiological traits relevant to drought stress resistance were recorded. The experimental results indicated that the AM fungus could almost compensate for the absence of root hairs under drought-stressed conditions. Moreover, phosphorus (P) concentration, leaf water potential, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency were significantly increased by R. intraradices but not by root hairs, except for shoot P concentration and photosynthetic rate under the drought condition. Root hairs even significantly decreased root P concentration under drought stresses. These results confirm that AM fungi can enhance plant drought tolerance by improvement of P uptake and plant water relations, which subsequently promote plant photosynthetic performance and growth, while root hairs presumably contribute to the improvement of plant growth and photosynthetic capacity through an increase in shoot P concentration.

  19. Spatio-temporal variation of core and satellite arbuscular mycorrhizal fungus communities in Miscanthus giganteus

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    Christopher James Barnes

    2016-08-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF are a group of obligate plant symbionts which can promote plant nutrition. AMF communities are diverse, but the factors which control their assembly in space and time remain unclear. In this study, the contributions of geographical distance, environmental heterogeneity and time to shaping AMF communities associated with Miscanthus giganteus were determined over a 13 month period. In particular, the community was partitioned into core (abundant and persistent taxa and satellite (taxa with low abundance and persistence constituents and the drivers of community assembly for each determined. We show that AMF richness and community composition changed over time associated with fluctuation within both the core and satellite communities. The degree to which AMF community variation was explained by soil properties was consistently higher in the core community than the combined and satellite communities, suggesting that the satellite community had considerable stochasticity associated with it. We suggest that the partitioning of communities into their core and satellite constituents could be employed to enhance the variation explained within microbial community analyses.

  20. Spatio-Temporal Variation of Core and Satellite Arbuscular Mycorrhizal Fungus Communities in Miscanthus giganteus

    Science.gov (United States)

    Barnes, Christopher J.; Burns, Caitlin A.; van der Gast, Christopher J.; McNamara, Niall P.; Bending, Gary D.

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are a group of obligate plant symbionts which can promote plant nutrition. AMF communities are diverse, but the factors which control their assembly in space and time remain unclear. In this study, the contributions of geographical distance, environmental heterogeneity and time in shaping AMF communities associated with Miscanthus giganteus (a perennial grass originating from south-east Asia) were determined over a 13 months period. In particular, the community was partitioned into core (abundant and persistent taxa) and satellite (taxa with low abundance and persistence) constituents and the drivers of community assembly for each determined. β-diversity was exceptionally low across the 140 m line transects, and there was limited evidence of geographical scaling effects on the composition of the core, satellite or combined communities. However, AMF richness and community composition changed over time associated with fluctuation within both the core and satellite communities. The degree to which AMF community variation was explained by soil properties was consistently higher in the core community than the combined and satellite communities, suggesting that the satellite community had considerable stochasticity associated with it. We suggest that the partitioning of communities into their core and satellite constituents could be employed to enhance the variation explained within microbial community analyses. PMID:27597844

  1. Antioxidant defenses of mycorrhizal fungus infection against SO(2)-induced oxidative stress in Avena nuda seedlings.

    Science.gov (United States)

    Huang, L L; Yang, C; Zhao, Y; Xu, X; Xu, Q; Li, G Z; Cao, J; Herbert, S J; Hao, L

    2008-11-01

    Colonization of arbuscular mycorrhizal fungi Glomus mosseae increased Avena nuda seedling tolerance to SO(2) exposure, as indicated by elevated total plant biomass and ameliorative photosynthetic rate, when compared to the non-mycorrhizal plants. This is associated with an improved antioxidant capacity as shown by enhanced superoxide dismutase and catalase activity, increased ascorbic acid and glutathione content, and reduced malondialdehyde and hydrogen peroxide level in the mycorrhizal plants relative to the non-mycorrhizal plants under SO(2) exposure. The mycorrhizal fungi colonization had no effect on the stomatal conductance. To our knowledge, this is the first finding of this sort.

  2. Fungos micorrízicos arbusculares no crescimento e nutrição de mudas de jenipapeiro Arbuscular mycorrhizal fungi in the growth and nutrition of jenipapo fruit tree seedlings

    Directory of Open Access Journals (Sweden)

    Ana Cristina Fermino Soares

    2012-03-01

    Full Text Available Alguns trabalhos têm demonstrado que a inoculação de fungos micorrízicos arbusculares (FMA na produção de mudas apresenta grande potencial para o desenvolvimento de um cultivo racional e eficiente de mudas de fruteiras. O objetivo neste trabalho foi avaliar a inoculação de fungos micorrízicos arbusculares no crescimento e nutrição de mudas de jenipapeiro (Genipa americana L.. O experimento foi conduzido em blocos casualizados, avaliando-se seis espécies fúngicas: Glomus clarum, Glomus etunicatum, Glomus manihots, Gigaspora albida, Acaulospora scrobiculata e Scutellospora heterogama, com dez repetições. As espécies A. scrobiculata, G. clarum e G. etunicatum colonizaram mais intensamente o sistema radicular e promoveram melhor desenvolvimento das mudas de jenipapeiro quando comparados a G. manihots e G. albida. O fungo G. etunicatum destacou-se, promovendo incrementos na altura (44,4%; no diâmetro do caule (63,6%; na produção de biomassa seca na parte aérea (288,8%, nas raízes (248,7% e na área foliar (315,7% em comparação às mudas controle. Com exceção de Mn e Fe, mudas inoculadas apresentaram teores de nutrientes superior às mudas controle. As mudas que receberam inóculo de S. heterogama apresentaram crescimento e teor de nutrientes similares aos das mudas controle. A colonização micorrízica correlacionou-se positivamente com os teores de N, P, K, Mg e Cu e negativamente com os teores de Fe e Mn nas folhas das mudas de jenipapeiro. O jenipapeiro é uma planta responsiva aos FMA e a inoculação beneficiou o crescimento e a nutrição das mudas.Some studies have shown that inoculation with arbuscular mycorrhizal fungi (AMF in seedling production has great potential for developing a rational and efficient cultivation of fruit tree seedlings. The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizal fungi on growth and nutrition of seedlings of genipap (Genipa americana L.. The

  3. Respuesta de Melinis minutiflora a la inoculación con hongos micorrícico arbusculares en un Inceptisol de Colombia Response of Melinis minutiflora to inoculation with arbuscular mycorrhizal fungi in an Inceptisol of Colombia

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    Lyda Minelly Zárate Quiroga

    2009-10-01

    without sterilization. Yield parameters were aerial and radical biomass, root length, mycorrhizal colonization and N, P, K, Ca, and Mg concentrations in the aerial biomass. Pots measuring 13.5 x 8.0 x 14.0 cm were used as experimental units. Inceptisol soil, with low nutrient availability, previously sieved and mixed with sand was used as substrate. Gi. margarita and Gl. manihotis inocula showed the best results in the accumulation of aerial and root biomass, root length, mycorrhizal colonization and concentration of elements in the aerial biomass, while Ku. colombiana presented inhibitory effects on the variables evaluated. ND substrate condition increased accumulation of aerial and radical biomass and P concentration in the aerial biomass, also stimulated root length of M. minutiflora. Aerial biomass had higher concentrations of N, K, Ca, and Mg in D substrate. Mellinis minutiflora is a promising grass species for rehabilitation of degraded soils in combination with arbuscular mycorrhizal fungi inoculation.

  4. Arbuscular mycorrhizal fungi and the occurrence of flavonoids in roots of passion fruit seedlings Fungos micorrízicos arbusculares e a ocorrência de flavonóides em raízes de mudas de maracujazeiro amarelo

    Directory of Open Access Journals (Sweden)

    Ana Cristina Fermino Soares

    2005-08-01

    Full Text Available Composition and the role of root flavonoids in the regulation of mycorrhizal symbiosis are still poorly understood. Several flavonoids stimulate spore germination, mycelia growth and root colonization by arbuscular mycorrhizal fungi (AMF, and both root colonization and flavonoid composition are affected by plant nutritional status. Effects of AMF on the occurrence and content of aromatic secondary metabolites in the roots of passion fruit seedlings grown under two levels of phosphorus (P fertilization (10 and 50 mg kg-1 of phosphorus was studied. Seedlings were inoculated with Glomus clarum and a population of native fungi from a passion fruit plantation. Methanolic extracts of passion fruit seedlings roots were analyzed by high performance liquid chromatography (HPLC. It was recorded the occurrence of several compounds, possibly flavonoids, with seven major peaks. The root contents of the compound with a retention time of 4.5 minutes, varied in response to the root colonization by different mycorrhizal fungi, and the contents of two compounds with retention times of 3.4 and 18.9 minutes varied due to the poor plant growth and nutritional status. Passion fruit seedlings have several aromatic compounds, and their contents were correlated with root colonization by different mycorrhizal fungi, the reduced seedling growth due to nutritional stress, and/or the plant defense responses to the fungi.Os flavonóides nas raízes e seu papel na regulação da simbiose com fungos micorrízicos não são bem conhecidos. Vários flavonóides estimulam a germinação de esporos, crescimento micelial e colonização micorrízica. Ambos, a colonização micorrízica e a composição de flavonóides nas raízes são afetados pelo estado nutricional da planta. Avaliou-se o efeito de fungos micorrízicos arbusculares sobre a ocorrência e concentração de substâncias, possivelmente metabólitos aromáticos secundários pertencentes à classe dos flavonóides, em

  5. Effects of biochar amendment and arbuscular mycorrhizal fungi inoculation on availability of soil phosphorus and growth of maize

    OpenAIRE

    A.E. Mau; S.R. Utami

    2014-01-01

    A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF) inoculation on phosphorus uptake by maize (Zea mayze L.) grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil) were arranged in a completely randomized block design with thr...

  6. Diversity of arbuscular mycorrhizal fungi in a chrono-sequence of alluvial and degraded soils due to mining processes in bajo cauca antioqueno, Colombia

    International Nuclear Information System (INIS)

    Arbuscular mycorrhizal fungi (AMF) presence and diversity were evaluated in undisturbed and disturbed soils form alluvial mining processes. The soils belong to the Tropic Fluvaquent, Typical Dystropept, and Typical Paleudult sub-groups which corresponded to Low, Middle and High terraces, respectively, of the Cauca river at Taraza town. AMF propagules were multiplied in Leonard jars under glass house conditions using sterile substrate, modified Hoagland's solution and different fractions of soil used as sources of inoculum, which corresponded to the size of the spores. A first assay was made in maize (Zea mays) which allowed mycorrhizal colonization in roots but not spore production. In a second assay, in kudzu (Pueraria phaseoloides) AMF spores and colonized roots were obtained with the treatments corresponding to propagules obtained from high terrace and disturbed soil. These treatments presented a significant effect on kudzu yield (P?0,001) respect to the other treatments. The AMF spores of undisturbed and disturbed soils showed low infective capacity. Nevertheless, propagules of AMF were multiplied in trap cultures, which produced spores of four morpho types. One of these was identified as G. microagregatum. The polymorphism obtained by RAPD's made possible the differentiation of these morpho types with the primer OPA2. Similitude above 38% was achieved using UPGMA system. The results indicated that four morpho types belong to the genus Glomus, but they possibly belong to different species. Our results are promissory in the differentiation of native strains of AMF with low number of spores collected from soil samples in rehabilitation processes, which normally is unknown.

  7. Occurrence and Structure of Arbuscular Mycorrhizal Fungal Communities in Cassava after Cultivation of Cover Crops as Observed by the “PCR-DGGE” Technique

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    Elaine dos Santos Heberle

    2015-10-01

    Full Text Available ABSTRACT Cassava (Manihot esculenta Crantz is a highly mycotrophic crop, and prior soil cover may affect the density of arbuscular mycorrhizal fungi (AMFs, as well as the composition of the AMFs community in the soil. The aim of this study was to evaluate the occurrence and the structure of AMFs communities in cassava grown after different cover crops, and the effect of the cover crop on mineral nutrition and cassava yield under an organic farming system. The occurrence and structure of the AMFs community was evaluated through polymerase chain reaction (PCR and denaturing gradient gel electrophoresis (DGGE. A randomized block experimental design was used with four replications. Six different cover crop management systems before cassava were evaluated: black oats, vetch, oilseed radish, intercropped oats + vetch, intercropped oats + vetch + oilseed radish, plus a control (fallow treatment mowed every 15 days. Oats as a single crop or oats intercropped with vetch or with oilseed radish increased AMFs inoculum potential in soil with a low number of propagules, thus benefiting mycorrhizal colonization of cassava root. The treatments did not affect the structure of AMFs communities in the soil since the AMFs communities were similar in cassava roots in succession to different cover crops. AMFs colonization was high despite high P availability in the soil. The cassava crop yield was above the regional average, and P levels in the leaves were adequate, regardless of which cover crop treatments were used. One cover crop cycle prior to the cassava crop was not enough to observe a significant response in variables, P in plant tissue, crop yield, and occurrence and structure of AMFs communities in the soil. In the cassava roots in succession, the plant developmental stage affected the groupings of the structure of the AMF community.

  8. Genetic Exchange in an Arbuscular Mycorrhizal Fungus Results in Increased Rice Growth and Altered Mycorrhiza-Specific Gene Transcription▿†

    Science.gov (United States)

    Colard, Alexandre; Angelard, Caroline; Sanders, Ian R.

    2011-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate symbionts with most terrestrial plants. They improve plant nutrition, particularly phosphate acquisition, and thus are able to improve plant growth. In exchange, the fungi obtain photosynthetically fixed carbon. AMF are coenocytic, meaning that many nuclei coexist in a common cytoplasm. Genetic exchange recently has been demonstrated in the AMF Glomus intraradices, allowing nuclei of different Glomus intraradices strains to mix. Such genetic exchange was shown previously to have negative effects on plant growth and to alter fungal colonization. However, no attempt was made to detect whether genetic exchange in AMF can alter plant gene expression and if this effect was time dependent. Here, we show that genetic exchange in AMF also can be beneficial for rice growth, and that symbiosis-specific gene transcription is altered by genetic exchange. Moreover, our results show that genetic exchange can change the dynamics of the colonization of the fungus in the plant. Our results demonstrate that the simple manipulation of the genetics of AMF can have important consequences for their symbiotic effects on plants such as rice, which is considered the most important crop in the world. Exploiting natural AMF genetic variation by generating novel AMF genotypes through genetic exchange is a potentially useful tool in the development of AMF inocula that are more beneficial for crop growth. PMID:21784911

  9. Difference in Striga-susceptibility is reflected in strigolactone secretion profile, but not in compatibility and host preference in arbuscular mycorrhizal symbiosis in two maize cultivars.

    Science.gov (United States)

    Yoneyama, Kaori; Arakawa, Ryota; Ishimoto, Keiko; Kim, Hyun Il; Kisugi, Takaya; Xie, Xiaonan; Nomura, Takahito; Kanampiu, Fred; Yokota, Takao; Ezawa, Tatsuhiro; Yoneyama, Koichi

    2015-05-01

    Strigolactones released from plant roots trigger both seed germination of parasitic weeds such as Striga spp. and hyphal branching of the symbionts arbuscular mycorrhizal (AM) fungi. Generally, strigolactone composition in exudates is quantitatively and qualitatively different among plants, which may be involved in susceptibility and host specificity in the parasite-plant interactions. We hypothesized that difference in strigolactone composition would have a significant impact on compatibility and host specificity/preference in AM symbiosis. Strigolactones in root exudates of Striga-susceptible (Pioneer 3253) and -resistant (KST 94) maize (Zea mays) cultivars were characterized by LC-MS/MS combined with germination assay using Striga hermonthica seeds. Levels of colonization and community compositions of AM fungi in the two cultivars were investigated in field and glasshouse experiments. 5-Deoxystrigol was exuded exclusively by the susceptible cultivar, while the resistant cultivar mainly exuded sorgomol. Despite the distinctive difference in strigolactone composition, the levels of AM colonization and the community compositions were not different between the cultivars. The present study demonstrated that the difference in strigolactone composition has no appreciable impact on AM symbiosis, at least in the two maize cultivars, and further suggests that the traits involved in Striga-resistance are not necessarily accompanied by reduction in compatibility to AM fungi. PMID:25754513

  10. Molecular biodiversity of arbuscular mycorrhizal fungi in trace metal-polluted soils.

    Science.gov (United States)

    Hassan, Saad El Din; Boon, Eva; St-Arnaud, Marc; Hijri, Mohamed

    2011-08-01

    We assessed the indigenous arbuscular mycorrhizal fungi (AMF) community structure from the roots and associated soil of Plantago major (plantain) plants growing on sites polluted with trace metals (TM) and on unpolluted sites. Uncontaminated and TM-contaminated sites containing As, Cd, Cu, Pb, Sn and Zn were selected based on a survey of the TM concentration in soils of community gardens in the City of Montréal. Total genomic DNA was extracted directly from these samples. PCR followed by denaturing gradient gel electrophoresis (PCR-DGGE), augmented by cloning and sequencing, as well as direct sequencing techniques, was all used to investigate AMF community structure. We found a decreased diversity of native AMF (assessed by the number of AMF ribotypes) in soils and plant roots harvested from TM-polluted soils compared with unpolluted soils. We also found that community structure was modified by TM contamination. Various species of Glomus, Scutellospora aurigloba and S. calospora were the most abundant ribotypes detected in unpolluted soil; ribotypes of G. etunicatum, G. irregulare/G. intraradices and G. viscosum were found in both polluted and unpolluted soils, while ribotypes of G. mosseae and Glomus spp. (B9 and B13) were dominant in TM-polluted soils. The predominance of G. mosseae in metal-polluted sites suggests the tolerance of this species to TM stress, as well as its potential use for phytoremediation. These data are relevant for our understanding of how AMF microbial communities respond to natural environments that contain a broad variety of toxic inorganic compounds and will substantially expand our knowledge of AMF ecology and biodiversity. PMID:21668808

  11. The Potential Role of Arbuscular Mycorrhizal Fungi in the Restoration of Degraded Lands

    Science.gov (United States)

    Asmelash, Fisseha; Bekele, Tamrat; Birhane, Emiru

    2016-01-01

    Experiences worldwide reveal that degraded lands restoration projects achieve little success or fail. Hence, understanding the underlying causes and accordingly, devising appropriate restoration mechanisms is crucial. In doing so, the ever-increasing aspiration and global commitments in degraded lands restoration could be realized. Here we explain that arbuscular mycorrhizal fungi (AMF) biotechnology is a potential mechanism to significantly improve the restoration success of degraded lands. There are abundant scientific evidences to demonstrate that AMF significantly improve soil attributes, increase above and belowground biodiversity, significantly improve tree/shrub seedlings survival, growth and establishment on moisture and nutrient stressed soils. AMF have also been shown to drive plant succession and may prevent invasion by alien species. The very few conditions where infective AMF are low in abundance and diversity is when the soil erodes, is disturbed and is devoid of vegetation cover. These are all common features of degraded lands. Meanwhile, degraded lands harbor low levels of infective AMF abundance and diversity. Therefore, the successful restoration of infective AMF can potentially improve the restoration success of degraded lands. Better AMF inoculation effects result when inocula are composed of native fungi instead of exotics, early seral instead of late seral fungi, and are consortia instead of few or single species. Future research efforts should focus on AMF effect on plant community primary productivity and plant competition. Further investigation focusing on forest ecosystems, and carried out at the field condition is highly recommended. Devising cheap and ethically widely accepted inocula production methods and better ways of AMF in situ management for effective restoration of degraded lands will also remain to be important research areas. PMID:27507960

  12. The impact of arbuscular mycorrhizal fungi on plant growth following herbivory: A search for pattern

    Science.gov (United States)

    Borowicz, Victoria A.

    2013-10-01

    Arbuscular mycorrhizal (AM) fungi can facilitate nutrient uptake and increase host plant growth but also place constraints on the host's carbon budget. When plants are stressed by herbivory the net effect of the symbiosis may be altered tolerance. Individual experiments manipulating AM fungi and herbivory have demonstrated increased, decreased, and no effect on tolerance but patterns with respect to plant, herbivore, or fungus characteristics have not emerged. Meta-analysis of published results from factorial experiments was used to describe the size of the effects of herbivory and of AM fungi on host growth when factors such as cause of damage, inoculum, and host characteristics are considered, and to determine whether AM fungi alter the effects of herbivory. Also, the correlation between the effect of AM fungi on tolerance and resistance was tested with data from studies that examined insect performance. Herbivory strongly and consistently reduced shoot and root growth, especially in perennial plants and crops. AM fungi increased shoot growth of perennials but not annuals, and when insects caused damage but not when artificial defoliation was applied. Root growth was consistently greater with AM fungi. The interaction of AM fungi and herbivory, which indicates whether AM fungi alter the effects of herbivory, was variable and never significant overall but homogeneity tests indicated underlying structure. In experiments that used single species inoculum, Glomus intraradices increased, whereas Glomus mosseae reduced, effects of herbivory on shoot growth. Multispecies inocula magnified effects of herbivory on root growth whereas single species inocula ameliorated effects. The impact of AM fungi on resistance to herbivory was positively correlated with the impact on tolerance; however AM fungi reduced both tolerance and resistance in many cases. Review of these results with respect to the types of systems studied suggests directions for future investigation.

  13. Arbuscular mycorrhizal fungi alleviate oxidative stress induced by ADOR and enhance antioxidant responses of tomato plants.

    Science.gov (United States)

    García-Sánchez, Mercedes; Palma, José Manuel; Ocampo, Juan Antonio; García-Romera, Inmaculada; Aranda, Elisabet

    2014-03-15

    The behaviour of tomato plants inoculated with arbuscular mycorrhizal (AM) fungi grown in the presence of aqueous extracts from dry olive residue (ADOR) was studied in order to understand how this symbiotic relationship helps plants to cope with oxidative stress caused by ADOR. The influence of AM symbiosis on plant growth and other physiological parameters was also studied. Tomato plants were inoculated with the AM fungus Funneliformis mosseae and were grown in the presence of ADOR bioremediated and non-bioremediated by Coriolopsis floccosa and Penicillium chrysogenum-10. The antioxidant response as well as parameters of oxidative damage were examined in roots and leaves. The data showed a significant increase in the biomass of AM plant growth in the presence of ADOR, regardless of whether it was bioremediated. The establishment and development of the symbiosis were negatively affected after plants were exposed to ADOR. No differences were observed in the relative water content (RWC) or PS II efficiency between non-AM and AM plants. The increase in the enzymatic activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione-S-transferase (GST; EC 2.5.1.18) were simultaneous to the reduction of MDA levels and H2O2 content in AM root growth in the presence of ADOR. Similar H2O2 levels were observed among non-AM and AM plants, although only AM plants showed reduced lipid peroxidation content, probably due to the involvement of antioxidant enzymes. The results highlight how the application of both bioremediated ADOR and AM fungi can alleviate the oxidative stress conditions, improving the growth and development of tomato plants. PMID:24594394

  14. Natural selection and the evolutionary ecology of the arbuscular mycorrhizal fungi (Phylum Glomeromycota).

    Science.gov (United States)

    Helgason, Thorunn; Fitter, Alastair H

    2009-01-01

    Darwin's model of evolution by natural selection was based on his observations of change in discrete organisms in which individuals are easy to define. Many of the most abundant functional groups in ecosystems, such as fungi and bacteria, do not fit this paradigm. In this review, we seek to understand how the elegant logic of Darwinian natural selection can be applied to distributed clonal organisms. The arbuscular mycorrhizal (AM) fungi are one such group. Globally, they are ubiquitous in terrestrial ecosystems, are locally distributed among many host plant species, and are significant drivers of nutrient cycling in ecosystems. The AM fungi are intractable to study, as the few taxa that can be cultured cannot be grown in the absence of plant roots. Research has focused on the plant-fungus interface, and thus on the symbiotic phenotype. A model is discussed for the interchange of materials at the interface that throws the emphasis of research onto the behaviour of the individual organisms and removes the need to test for phenomena such as selectivity, co-evolution, and cheating. The AM fungi are distributed organisms with an extensive external mycelium that is likely to be under strong environmental selection. AM fungi show sufficient phenotypic variation and fitness differentials for selection to occur, and developments in genetic analyses suggest that a better understanding of heritability in these organisms is not far away. It is argued that direct selection on fungal traits related to their survival and performance in the soil independent of the host is likely to be the major driver of differentiation in the AM fungi, and the evidence for direct fungal responses to soil conditions such as pH, hypoxia, and temperature is reviewed.

  15. Mitochondrial comparative genomics and phylogenetic signal assessment of mtDNA among arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Nadimi, Maryam; Daubois, Laurence; Hijri, Mohamed

    2016-05-01

    Mitochondrial (mt) genes, such as cytochrome C oxidase genes (cox), have been widely used for barcoding in many groups of organisms, although this approach has been less powerful in the fungal kingdom due to the rapid evolution of their mt genomes. The use of mt genes in phylogenetic studies of Dikarya has been met with success, while early diverging fungal lineages remain less studied, particularly the arbuscular mycorrhizal fungi (AMF). Advances in next-generation sequencing have substantially increased the number of publically available mtDNA sequences for the Glomeromycota. As a result, comparison of mtDNA across key AMF taxa can now be applied to assess the phylogenetic signal of individual mt coding genes, as well as concatenated subsets of coding genes. Here we show comparative analyses of publically available mt genomes of Glomeromycota, augmented with two mtDNA genomes that were newly sequenced for this study (Rhizophagus irregularis DAOM240159 and Glomus aggregatum DAOM240163), resulting in 16 complete mtDNA datasets. R. irregularis isolate DAOM240159 and G. aggregatum isolate DAOM240163 showed mt genomes measuring 72,293bp and 69,505bp with G+C contents of 37.1% and 37.3%, respectively. We assessed the phylogenies inferred from single mt genes and complete sets of coding genes, which are referred to as "supergenes" (16 concatenated coding genes), using Shimodaira-Hasegawa tests, in order to identify genes that best described AMF phylogeny. We found that rnl, nad5, cox1, and nad2 genes, as well as concatenated subset of these genes, provided phylogenies that were similar to the supergene set. This mitochondrial genomic analysis was also combined with principal coordinate and partitioning analyses, which helped to unravel certain evolutionary relationships in the Rhizophagus genus and for G. aggregatum within the Glomeromycota. We showed evidence to support the position of G. aggregatum within the R. irregularis 'species complex'. PMID:26868331

  16. Belowground interactions with aboveground consequences: Invasive earthworms and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Paudel, Shishir; Longcore, Travis; MacDonald, Beau; McCormick, Melissa K; Szlavecz, Katalin; Wilson, Gail W T; Loss, Scot R

    2016-03-01

    A mounting body of research suggests that invasive nonnative earthworms substantially alter microbial communities, including arbuscular mycorrhizal fungi (AMF). These changes to AMF can cascade to affect plant communities and vertebrate populations. Despite these research advances, relatively little is known about (1) the mechanisms behind earthworms' effects on AMF and (2) the factors that determine the outcomes of earthworm-AMF interactions (i.e., whether AMF abundance is increased or decreased and subsequent effects on plants). We predict that AMF-mediated effects of nonnative earthworms on ecosystems are nearly universal because (1) AMF are important components of most terrestrial ecosystems, (2) nonnative earthworms have become established in nearly every type of terrestrial ecosystem, and (3) nonnative earthworms, due to their burrowing and feeding behavior, greatly affect AMF with potentially profound concomitant effects on plant communities. We highlight the multiple direct and indirect effects of nonnative earthworms on plants and review what is currently known about the interaction between earthworms and AMF. We also illustrate how the effects of nonnative earthworms on plant-AMF mutualisms can alter the structure and stability of aboveground plant communities, as well as the vertebrate communities relying on these habitats. Integrative studies that assess the interactive effects of earthworms and AMF can provide new insights into the role that belowground ecosystem engineers play in altering aboveground ecological processes. Understanding these processes may improve our ability to predict the structure of plant and animal communities in earthworm-invaded regions and to develop management strategies that limit the numerous undesired impacts of earthworms. PMID:27197388

  17. The Potential Role of Arbuscular Mycorrhizal Fungi in the Restoration of Degraded Lands.

    Science.gov (United States)

    Asmelash, Fisseha; Bekele, Tamrat; Birhane, Emiru

    2016-01-01

    Experiences worldwide reveal that degraded lands restoration projects achieve little success or fail. Hence, understanding the underlying causes and accordingly, devising appropriate restoration mechanisms is crucial. In doing so, the ever-increasing aspiration and global commitments in degraded lands restoration could be realized. Here we explain that arbuscular mycorrhizal fungi (AMF) biotechnology is a potential mechanism to significantly improve the restoration success of degraded lands. There are abundant scientific evidences to demonstrate that AMF significantly improve soil attributes, increase above and belowground biodiversity, significantly improve tree/shrub seedlings survival, growth and establishment on moisture and nutrient stressed soils. AMF have also been shown to drive plant succession and may prevent invasion by alien species. The very few conditions where infective AMF are low in abundance and diversity is when the soil erodes, is disturbed and is devoid of vegetation cover. These are all common features of degraded lands. Meanwhile, degraded lands harbor low levels of infective AMF abundance and diversity. Therefore, the successful restoration of infective AMF can potentially improve the restoration success of degraded lands. Better AMF inoculation effects result when inocula are composed of native fungi instead of exotics, early seral instead of late seral fungi, and are consortia instead of few or single species. Future research efforts should focus on AMF effect on plant community primary productivity and plant competition. Further investigation focusing on forest ecosystems, and carried out at the field condition is highly recommended. Devising cheap and ethically widely accepted inocula production methods and better ways of AMF in situ management for effective restoration of degraded lands will also remain to be important research areas. PMID:27507960

  18. Changes in communities of Fusarium and arbuscular mycorrhizal fungi as related to different asparagus cultural factors.

    Science.gov (United States)

    Yergeau, Etienne; Vujanovic, Vladimir; St-Arnaud, Marc

    2006-07-01

    Asparagus (Asparagus officinalis) is a high-value perennial vegetable crop that has shown a marked decline in productivity after many years of continuous harvesting. This decline is caused by an increase in both abiotic (autotoxicity, harvesting pressure) and biotic stresses [fungal infections, mainly Fusarium crown and root rot (FCRR)]. To gain insight into disease development and possible mitigation strategies, we studied the effects of harvesting, time in the growing season, and field age on FCRR development, Fusarium species composition, and arbuscular mycorrhizal fungi (AMF) communities in both a controlled field experiment and an ecological survey of commercial fields. In one experiment, a 3-year-old asparagus field was subdivided into plots that were harvested or not and sampled throughout the growing season to assess short-term dominant Fusarium species shifts. In addition, diseased and healthy asparagus plants sampled from six commercial fields in the same geographical region were used to assess Fusarium and AMF communities in relation to different parameters. Fusarium and AMF communities were described by using a polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) approach, and results were analyzed by mainly correspondence analysis and canonical correspondence analysis. Results showed that dominant Fusarium taxa assemblages changed throughout the growing season. Harvested plots had significantly more FCRR symptomatic plants at the end of the growing season, but this effect was not related with any trend in Fusarium community structure. Sampling site and plant age significantly influenced AMF community structure, whereas only sampling site consistently influenced the Fusarium community. Diseased and healthy plants harbored similar Fusarium and AMF communities. Shifts in Fusarium community might not be responsible for different disease incidence because they are ubiquitous regardless of plant health status or harvesting regime

  19. Belowground interactions with aboveground consequences: Invasive earthworms and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Paudel, Shishir; Longcore, Travis; MacDonald, Beau; McCormick, Melissa K; Szlavecz, Katalin; Wilson, Gail W T; Loss, Scot R

    2016-03-01

    A mounting body of research suggests that invasive nonnative earthworms substantially alter microbial communities, including arbuscular mycorrhizal fungi (AMF). These changes to AMF can cascade to affect plant communities and vertebrate populations. Despite these research advances, relatively little is known about (1) the mechanisms behind earthworms' effects on AMF and (2) the factors that determine the outcomes of earthworm-AMF interactions (i.e., whether AMF abundance is increased or decreased and subsequent effects on plants). We predict that AMF-mediated effects of nonnative earthworms on ecosystems are nearly universal because (1) AMF are important components of most terrestrial ecosystems, (2) nonnative earthworms have become established in nearly every type of terrestrial ecosystem, and (3) nonnative earthworms, due to their burrowing and feeding behavior, greatly affect AMF with potentially profound concomitant effects on plant communities. We highlight the multiple direct and indirect effects of nonnative earthworms on plants and review what is currently known about the interaction between earthworms and AMF. We also illustrate how the effects of nonnative earthworms on plant-AMF mutualisms can alter the structure and stability of aboveground plant communities, as well as the vertebrate communities relying on these habitats. Integrative studies that assess the interactive effects of earthworms and AMF can provide new insights into the role that belowground ecosystem engineers play in altering aboveground ecological processes. Understanding these processes may improve our ability to predict the structure of plant and animal communities in earthworm-invaded regions and to develop management strategies that limit the numerous undesired impacts of earthworms.

  20. Development and amplification of multiple co-dominant genetic markers from single spores of arbuscular mycorrhizal fungi by nested multiplex PCR

    DEFF Research Database (Denmark)

    Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

    2005-01-01

    Multiple co-dominant genetic markers from single spores of the arbuscular mycorrhizal (AM) fungi Glomus mosseae, Glomus caledonium, and Glomus geosporum were amplified by nested multiplex PCR using a combination of primers for simultaneous amplification of five loci in one PCR. Subsequently, each...

  1. A comparison of the development and metabolic activity of mycorrhizas formed by arbuscular mycorrhizal fungi from different genera on two tropical forage legumes

    NARCIS (Netherlands)

    Boddington, C.L.; Dodd, J.C.

    1998-01-01

    Two glasshouse experiments were done to assess the development and metabolic activity of mycorrhizas formed by isolates of arbuscular mycorrhizal fungi (AMF) from three different genera, Acaulospora, Gigaspora and Glomus on either Pueraria phaseoloides L. or Desmodium ovalifolium L. plants. The seco

  2. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime;

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reduci...

  3. Species richness and spore abundance of arbuscular mycorrhizal fungi across distinct land uses in western Brazilian Amazon.

    Science.gov (United States)

    Stürmer, Sidney Luiz; Siqueira, José Oswaldo

    2011-05-01

    Arbuscular mycorrhizal fungi (AMF) were surveyed for species richness and abundance in sporulation in six distinct land uses in the western Amazon region of Brazil. Areas included mature pristine forest and sites converted to pasture, crops, agroforestry, young and old secondary forest. A total of 61 AMF morphotypes were recovered and 30% of them could not be identified to known species. Fungal communities were dominated by Glomus species but Acaulospora species produced the most abundant sporulation. Acaulospora gedanensis cf., Acaulospora foveata, Acaulospora spinosa, Acaulospora tuberculata, Glomus corymbiforme, Glomus sp15, Scutellospora pellucida, and Archaeospora trappei sporulated in all land use areas. Total spore numbers were highly variable among land uses. Mean species richness in crop, agroforestry, young and old secondary forest sites was twice that in pristine forest and pasture. fungal communities were dominated in all land use areas except young secondary forest by two or three species which accounted for 48% to 63% of all sporulation. Land uses influenced AMF community in (1) frequency of occurrence of sporulating AMF species, (2) mean species diversity, and (3) relative spore abundance. Conversion of pristine forest into distinct land uses does not appear to reduce AMF diversity. Cultural practices adopted in this region maintain a high diversity of arbuscular mycorrhizal fungi.

  4. Root endophyte symbiosis in vitro between the ectomycorrhizal basidiomycete Tricholoma matsutake and the arbuscular mycorrhizal plant Prunus speciosa.

    Science.gov (United States)

    Murata, Hitoshi; Yamada, Akiyoshi; Yokota, Satoru; Maruyama, Tsuyoshi; Endo, Naoki; Yamamoto, Kohei; Ohira, Tatsuro; Neda, Hitoshi

    2014-05-01

    We previously reported that Tricholoma matsutake and Tricholoma fulvocastaneum, ectomycorrhizal basidiomycetes that associate with Pinaceae and Fagaceae, respectively, in the Northern Hemisphere, could interact in vitro as a root endophyte of somatic plants of Cedrela odorata (Meliaceae), which naturally harbors arbuscular mycorrhizal fungi in South America, to form a characteristic rhizospheric colony or "shiro". We questioned whether this phenomenon could have occurred because of plant-microbe interactions between geographically separated species that never encounter one another in nature. In the present study, we document that these fungi formed root endophyte interactions and shiro within 140 days of inoculation with somatic plants of Prunus speciosa (=Cerasus speciosa, Rosaceae), a wild cherry tree that naturally harbors arbuscular mycorrhizal fungi in Japan. Compared with C. odorata, infected P. speciosa plants had less mycelial sheath surrounding the exodermis, and the older the roots, especially main roots, the more hyphae penetrated. In addition, a large number of juvenile roots were not associated with hyphae. We concluded that such root endophyte interactions were not events isolated to the interactions between exotic plants and microbes but could occur generally in vitro. Our pure culture system with a somatic plant allowed these fungi to express symbiosis-related phenotypes that varied with the plant host; these traits are innately programmed but suppressed in nature and could be useful in genetic analyses of plant-fungal symbiosis. PMID:24158697

  5. Arbuscular mycorrhizal fungi diversity influenced by different agricultural management practices in a semi-arid Mediterranean agro-ecosystem

    Science.gov (United States)

    de Mar Alguacil, Maria; Torrecillas, Emma; Garcia-Orenes, Fuensanta; Torres, Maria Pilar; Roldan, Antonio

    2013-04-01

    The arbuscular mycorrhizal fungi (AMF) are a key, integral component of the stability, sustainability and functioning of ecosystems. In this study a field experiment was performed at the El Teularet-Sierra de Enguera Experimental Station (eastern Spain) to assess the influence during a 6-yr period of different agricultural practices on the diversity of arbuscular mycorrhizal fungi (AMF). The management practices included residual herbicide use, ploughing, ploughing + oats, addition of oat straw mulch and a control (land abandonment). Adjacent soil under natural vegetation was used as a reference for local, high-quality soil and as a control for comparison with the agricultural soils under different management practices. The AM fungal small-subunit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Thirty-six different phylotypes were identified, which were grouped in four families: Glomeraceae, Paraglomeraceae, Ambisporaceae and Claroideoglomeraceae. The first results showed significant differences in the distribution of the AMF phylotypes as consequence of the difference between agricultural management practices. Thus, the lowest diversity was observed for the plot that was treated with herbicide. The management practices including ploughing and ploughing + oats had similar AMF diversity. Oat straw mulching yielded the highest number of different AMF sequence types and showed the highest diversity index. Thus, this treatment could be more suitable in sustainable soil use and therefore protection of biodiversity.

  6. Gate crashing arbuscular mycorrhizas: in vivo imaging shows the extensive colonization of both symbionts by Trichoderma atroviride.

    Science.gov (United States)

    Lace, Beatrice; Genre, Andrea; Woo, Sheridan; Faccio, Antonella; Lorito, Matteo; Bonfante, Paola

    2015-02-01

    Plant growth-promoting fungi include strains of Trichoderma species that are used in biocontrol, and arbuscular mycorrhizal (AM) fungi, that enhance plant nutrition and stress resistance. The concurrent interaction of plants with these two groups of fungi affects crop performance but has only been occasionally studied so far. Using in vivo imaging of green fluorescent protein-tagged lines, we investigated the cellular interactions occurring between Trichoderma atroviride PKI1, Medicago truncatula and two Gigaspora species under in vitro culture conditions. Trichoderma atroviride did not activate symbiotic-like responses in the plant cells, such as nuclear calcium spiking or cytoplasmic aggregations at hyphal contact sites. Furthermore, T. atroviride parasitized G. gigantea and G. margarita hyphae through localized wall breaking and degradation - although this was not associated with significant chitin lysis nor the upregulation of two major chitinase genes. Trichoderma atroviride colonized broad areas of the root epidermis, in association with localized cell death. The infection of both symbionts was also observed when T. atroviride was applied to a pre-established AM symbiosis. We conclude that - although this triple interaction is known to improve plant growth in agricultural environments - in vitro culture demonstrate a particularly aggressive mycoparasitic and plant-colonizing behaviour of a biocontrol strain of Trichoderma.

  7. 丛枝菌根影响纳米 ZnO 对玉米的生物效应%Arbuscular Mycorrhizal Symbiosis Influences the Biological Effects of Nano-ZnO on Maize

    Institute of Scientific and Technical Information of China (English)

    王卫中; 王发园; 李帅; 刘雪琴

    2014-01-01

    人工纳米颗粒(engineered nanoparticles, ENPs)能被植物吸收、积累,随食物链进入人体而引起健康风险。丛枝菌根(arbuscular mycorrhizal, AM)真菌可与陆地生态系统中绝大多数高等植物互惠共生,可能影响 ENPs 的生物效应。在温室土壤盆栽条件下研究了施加不同水平纳米 ZnO(0、500、1000、2000、3000 mg•kg -1)和接种 AM 真菌 Acaulospora mellea 对玉米生长和营养状况的影响。结果表明,随土壤中纳米 ZnO 施加水平的增加,菌根侵染率和玉米生物量均呈降低趋势,根系总长、总表面积及总体积降低,植株体内 Zn 含量和吸收量逐渐增加,地上部分 P、 N、 K、 Fe、 Cu 吸收量逐渐降低。与对照相比,接种AM 真菌均促进玉米的生长,改善 P、 N、 K 营养,根系总长、总表面积及总体积增加,并在施加纳米 ZnO 时增加 Zn 在玉米根系中的分配比例。本结果首次表明,土壤中纳米 ZnO 对丛枝菌根具有一定毒性,而接种 AM 真菌能够减轻其毒性,对宿主植物起到保护作用。%Engineered nanoparticles (ENPs) can be taken up and accumulated in plants, then enter human bodies via food chain, and thus cause potential health risk. Arbuscular mycorrhizal fungi form mutualistic symbioses with the majority of higher plants in terrestrial ecosystems, and potentially influence the biological effects of ENPs. The present greenhouse pot culture experiment studied the effects of inoculation with or without arbuscular mycorrhizal fungus Acaulospora mellea on growth and nutritional status of maize under different nano-ZnO levels (0, 500, 1 000, 2 000 and 3 000 mg•kg - 1 ) artificially added into soil. Results showed that with the increasing nano-ZnO levels in soil, mycorrhizal colonization rate and biomass of maize plants showed a decreasing trend, total root length, total surface area and total volume reduced, while Zn concentration and uptake in plants gradually increased, and P, N, K, Fe

  8. Incremento no desenvolvimento do porta-enxerto de pessegueiro "Aldrighi" por fungos micorrízicos arbusculares autóctones Development increase of 'Aldrighi' peach rootstocks by indigenous arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    José Luis da Silva Nunes

    2008-12-01

    Full Text Available Objetivou-se, neste trabalho, avaliar a influência de três espécies de fungos micorrízicos arbusculares (FMA isolados de pomares de pessegueiro sobre o crescimento vegetativo, nutrição mineral e substâncias de reserva em plantas do porta-enxerto de pessegueiro cv. Aldrighi [Prunus persica (L. Batsch]. O delineamento experimental utilizado foi o de blocos casualizados, com dez plantas por parcela e quatro repetições. As plantas inoculadas com Glomus etunicatum apresentaram maior altura, diâmetro, área foliar, biomassa fresca e seca, nutrição mineral e substâncias de reserva da parte aérea, enquanto as inoculadas com Glomus clarum induziram um crescimento intermediário, superior àquelas inoculadas com Gigaspora margarita, que apresentaram resultados semelhantes às plantas não inoculadas. O desempenho foi relacionado com as taxas de colonização que nas plantas inoculadas com Glomus etunicatum e Glomus clarum foram de 92% e 77% respectivamente, enquanto Gigaspora margarita colonizou somente 30% das raízes.This work aimed to evaluate the influence of three arbuscular mycorrhizal fungi (AMF species on the vegetative growth, mineral nutrition and carbohidrate contents on peach rootstocks cv. Aldrighi [Prunus persica (L. Batsch]. The experimental desing was the one of randomized blocks, with ten plants per plots and four repetitions. Plants inoculated with Glomus etunicatum presented larger stem height, stem diameter, foliar area, fresh and dry shoot biomass, leaf mineral nutrition and carbohidrate contents, while those inoculated with Glomus clarum induced an intermediate growth, higher to those inoculated with Gigaspora margarita that presented results similar to the non inoculated plants. Plant growth performance was related to colonization taxes, which were, respectively, 92%, 77% and 30% to Glomus etunicatum, Glomus clarum and Gigaspora margarita inoculated plants.

  9. POTENCIAL SIMBIOTICO Y EFECTIVIDAD DE HONGOS MICORRIZO ARBUSCULARES DE TRES SUELOS SOMETIDOS A DIFERENTES USOS MYCORRHIZAL SYMBIOTIC POTENTIAL AND EFFECTIVENESS OF THREE SOILS UNDER DIFFERENT USES

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Jaramillo Padilla

    2004-06-01

    consisting of a soil-quartz (1:1 ratio mixture. The substrate was inoculated with a crude inoculum of Glomus aggregatum, a mycorrhizal fungus of known effectiveness. Mycorrhizal effectiveness was evaluated by monitoring P pinnule content of the leucaena seedlings at regular intervals of time during the growth period of 49 days. At harvest, shoot dry mass, shoot P content, and mycorrhizal colonization were determined. Plant growth and P uptake were significantly higher in plants growing in the substrate inoculated with G. aggregatum than those plants grown in either non-inoculated substrate or substrate inoculated with aliquots of tested soils. Mycorrhizal colonization was very high in the G. aggregtaum inoculated-substrate and virtually absent in the other treatments. Results suggest that in the tested soils there were a low mycorrhizal effectiveness and/or low content of mycorrizal infective propagules, which was confirmed by the most-probable-number method and mycorrhizal spore counting.

  10. Especies de hongos formadores de Micorrizas Arbusculares: nuevas citas para la República Argentina Arbuscular mycorrhizal fungal species: new records for Argentina

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    G. Irrazabal

    2005-07-01

    Full Text Available Se investigó la presencia de hongos formadores de micorrizas arbusculares asociados a plantas colectadas en un agroecosistema y en un bosque nativo de tala, en la provincia de Buenos Aires. Las especies que constituyen un nuevo registro para la Argentina son: Scutellospora dipapillosa (Walker & Koske Walker & Sanders y Scutellospora fulgida Koske & Walker halladas en la rizósfera de Triticum aestivum L.; Scutellospora gilmorei (Trappe & Gerd. Walker & Sanders, en la rizósfera de Celtis tala Gill. Ex Planch., Scutia buxifolia Reiss. y plantas herbáceas; Acaulospora delicata Walker, Pfeiffer & Bloss. y Glomus clarum Nicolson & Schenck, halladas en ambos sitios. Estas especies son citadas, descriptas e ilustradas por primera vez para Argentina. Glomus etunicatum Becker & Gerdemann ha sido citada pero no descripta e ilustrada para nuestro país.The presence of arbuscular mycorrhizal fungi associated with plants from an agroecosystem and a native forest, in Buenos Aires province is studied. The species that correspond a new register for Argentina are: Scutellospora dipapillosa (Walker & Koske Walker & Sanders and Scutellospora fulgida Koske & Walker found in the rhizosphere of Triticum aestivum L.; Scutellospora gilmorei (Trappe & Gerd. Walker & Sanders, in the rhizosphere of Celtis tala Gill. Ex Planch., Scutia buxifolia Reiss. and herbaceous plants; Acaulospora delicata Walker, Pfeiffer & Bloss. and Glomus clarum Nicolson & Schenck, occurred in both sites. They are cited, described and illustrated for the first time from Argentina. Glomus etunicatum Becker & Gerdemann was previously cited although it was not described and illustrated from Argentina.

  11. Indicadores para seleccionar inóculos de hongos micorrícicos arbusculares eficientes en suelos moderadamente ácidos Indicators to select efficient arbuscular mycorrhizal fungi inocula in moderately acidic soils

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    F Covacevich

    2010-07-01

    potenciales cepas de HMA a introducir. La actividad ALP es un parámetro que evidenció la actividad de los HMA y presentó buena correlación con la respuesta de crecimiento. La producción de raíces combinada con el porcentaje de micorrización mostró ser un parámetro de utilidad, sin embargo hay que considerar que en condiciones de campo no es factible cuantificar el peso radical total obtenido por planta. El crecimiento en altura de la planta, puede, en algunos casos, ser un parámetro de utilidad.The propagules of arbuscular mycorrhizal fungi (AMF in soils are sometimes insufficient in number or efficiency to increase the growth of host plants. That situation could be resolved by inoculating the soils with indigenous or nonin-digenous AMF. However, it must take into account that soils may differ in their receptivity to the introduced AMF. The aim of this work was to select parameters as indicators of the presence, activity and benefit of plant-symbiotic non-indigenous AMF which can be used as inoculants in moderately acidic soils. We evaluated how inoculation with AMF affected mycorrhizal colonization and growth parameters of model onion plants grown in two moderately acid soils of different origin (Argentina and France. Inoculation with Glomus claroideum and Acaulospora longula in the Argentinean soil produced the highest AMF colonization of roots, total alkaline phosphatase activity (ALP and highest mycorrhizal response (MR. In the soil from France, inoculation with A. longula produced the highest amount of mycorrhizal roots and plant growth. Inoculation with Scutellospora pellucida produced an appropriate MR in the Argentinean soil but no significant MR was detected in the soil from France. G. clarum showed a high capacity to colonize roots but low efficiency for MR. Inoculation with A. laevins produced the lowest levels of colonization and MR in both soils. Direct and multivariate analysis of the tested parameters showed that the accumulation of dry shoot matter

  12. Glucosinolate profiles change during the life cycle and mycorrhizal colonization in a Cd/Zn hyperaccumulator Thlaspi praecox (Brassicaceae).

    Science.gov (United States)

    Pongrac, Paula; Vogel-Mikus, Katarina; Regvar, Marjana; Tolrà, Roser; Poschenrieder, Charlotte; Barceló, Juan

    2008-08-01

    Thlaspi praecox Wulfen (Brassicaceae) is a perennial Cd/Zn hyperaccumulating plant species that forms functional arbuscular mycorrhizal (AM) symbiosis. Glucosinolates (GS) were studied in different organs of field-collected T. praecox at differing plant developmental stages. Additionally, AM colonization was recorded. Total GS concentrations and profiles of nine individual GS varied during the plant life cycle. Novel individual GS that were related to specific developmental phases, mainly to flowering and seed production, were identified. The highest total GS and sinalbin concentrations in rosette leaves were found in the vegetative phase, possibly contributing to protection of young, palatable leaves. The lowest were found in roots during the flowering and the seeding phases. Increased total GS concentrations in roots and enhanced aliphatic GS, especially glucobrassicanapin, in the senescence phase may protect roots from herbivory during winter and early spring. The presence of glucotropaeolin and the absence of glucobrassicanapin in the flowering phase coincided with peak AM colonization. This is the first report on GS profiles in an AM and metal-hyperaccumulating plant. PMID:18584257

  13. Ambispora granatensis, a new arbuscular mycorrhizal fungus, associated with Asparagus officinalis in Andalucia (Spain).

    Science.gov (United States)

    Palenzuela, Javier; Barea, José-Miguel; Ferrol, Nuria; Oehl, Fritz

    2011-01-01

    A new dimorphic fungal species in the arbuscular mycorrhiza-forming Glomeromycota, Ambispora granatensis, was isolated from an agricultural site in the province of Granada (Andalucía, Spain) growing in the rhizosphere of Asparagus officinalis. It was propagated in pot cultures with Trifolium pratense and Sorghum vulgare. The fungus also colonized Ri T-DNA transformed Daucus carota roots but did not form spores in these root organ cultures. The spores of the acaulosporoid morph are 90-150 μm diam and hyaline to white to pale yellow. They have three walls and a papillae-like rough irregular surface on the outer surface of the outer wall. The irregular surface might become difficult to detect within a few hours in lactic acid-based mountings but are clearly visible in water. The structural central wall layer of the outer wall is only 0.8-1.5 μm thick. The glomoid spores are formed singly or in small, loose spore clusters of 2-10 spores. They are hyaline to pale yellow, (25)40-70 μm diam and have a bilayered spore wall without ornamentation. Nearly full length sequences of the 18S and the ITS regions of the ribosomal gene place the new fungus in a separate clade next to Ambispora fennica and Ambispora gerdemannii. The acaulosporoid spores of the new fungus can be distinguished easily from all other spores in genus Ambispora by the conspicuous thin outer wall. PMID:20952800

  14. Action Mechanisms of Arbuscular Mycorrhizal Fungi in Phosphorus Uptake by Capsicum annuum L.

    Institute of Scientific and Technical Information of China (English)

    M. SHARIF; N. CLAASSEN

    2011-01-01

    A pot experiment was conducted to investigate the action mechanisms of arbuscular mycorrhizal (AM) fungi in phosphorus (P) uptake of Capsicum annuum L.in a sterilized fossil Oxisol. Three P levels of 0,10 and 200 mg kg-1 soil (P0,P10 and P200,respectively) without and with AM fungal inoculation were applied as Ca(H2PO4)2·H2O.Shoot dry matter yields and shoot P uptake increased significantly (P > 0.05) by the inoculation of AM fungi at P0 and P10.Root length and P concentration in soil solution increased with the inoculation of AM fungi but the root:shoot ratio decreased or remained constant.Around 50% roots of inoculated plants were infected by AM and the external hyphae amounted to 20 m g-1 soil at P10 and P200.The hyphae surface area of the infected root cylinder amounted to 11 and 2 cm2 cm-2 root at P0 and P10,respectively.The increased P uptake of inoculated plants was mainly because of an up to 5 times higher P influx of the infected root.Model calculations showed that the root alone could not have achieved the measured P influx in both infected and non-infected roots.But the P influx for hyphae calculated by the model was even much higher than the measured one.The P uptake capacity of hyphae introduced in the model was too high.Model calculations further showed that the depletion zone around roots or hyphae was very narrow.In the case of the root only 7% of the soil volume would contribute P to the plant,while in the case of hyphae it would be 100%.The results together with the model calculations showed that the increased P uptake of AM inoculated plants could be explained partly by the increased P concentration in the soil solution and by the increased P absorbing surface area coming from the external hyphae.

  15. Arbuscular Mycorrhizal Fungi as Natural Biofertilizers: Let's Benefit from Past Successes.

    Science.gov (United States)

    Berruti, Andrea; Lumini, Erica; Balestrini, Raffaella; Bianciotto, Valeria

    2015-01-01

    Arbuscular Mycorrhizal Fungi (AMF) constitute a group of root obligate biotrophs that exchange mutual benefits with about 80% of plants. They are considered natural biofertilizers, since they provide the host with water, nutrients, and pathogen protection, in exchange for photosynthetic products. Thus, AMF are primary biotic soil components which, when missing or impoverished, can lead to a less efficient ecosystem functioning. The process of re-establishing the natural level of AMF richness can represent a valid alternative to conventional fertilization practices, with a view to sustainable agriculture. The main strategy that can be adopted to achieve this goal is the direct re-introduction of AMF propagules (inoculum) into a target soil. Originally, AMF were described to generally lack host- and niche-specificity, and therefore suggested as agriculturally suitable for a wide range of plants and environmental conditions. Unfortunately, the assumptions that have been made and the results that have been obtained so far are often worlds apart. The problem is that success is unpredictable since different plant species vary their response to the same AMF species mix. Many factors can affect the success of inoculation and AMF persistence in soil, including species compatibility with the target environment, the degree of spatial competition with other soil organisms in the target niche and the timing of inoculation. Thus, it is preferable to take these factors into account when "tuning" an inoculum to a target environment in order to avoid failure of the inoculation process. Genomics and transcriptomics have led to a giant step forward in the research field of AMF, with consequent major advances in the current knowledge on the processes involved in their interaction with the host-plant and other soil organisms. The history of AMF applications in controlled and open-field conditions is now long. A review of biofertilization experiments, based on the use of AMF, has here

  16. Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants

    Science.gov (United States)

    Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A.; Abd_Allah, Elsayed F.; Alqarawi, A. A.; Alyemeni, Mohammed N.; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones.

  17. Short-term temporal variation in sporulation dynamics of arbuscular mycorrhizal (AM) fungi and physico-chemical edaphic properties of wheat rhizosphere.

    Science.gov (United States)

    Panwar, Vipin; Meghvansi, M K; Siddiqui, Sazada

    2011-07-01

    In this study, we investigated the pattern of short-term temporal variation in the arbuscular mycorrhizal (AM) fungi and physico-chemical edaphic properties of some wheat growing areas of the Bundelkhand region, Central India. Rhizospheric soil samples were collected every month from December 2007 to May 2008 from four wheat growing sites around Jhansi (Bundelkhand region). AM fungal root colonization, sporulation and physico-chemical edaphic properties during this period were determined and compared to evaluate the dynamics of response of wheat towards the AMF along crop maturation. Maximum AMF root colonization recorded was 54.3% indicating that AMF, particularly in low phosphorus (P) soils, can be important even in case of less responsive crop like wheat. In the two out of four sites studied, the AMF spore density increased with the increase in soil temperature. Absence of this type of pattern in remaining two sites indicated that site-specific environmental and agricultural conditions may affect the degree of wheat response to AMF. It also suggested that AMF communities inhabiting agroecosystems may exhibit considerable temporal sporulation patterns. The maximum AMF colonization was observed during February-March 2008, whereas maximum AMF sporulation was noticed during March-April 2008. Statistically significant negative correlation of AMF spore density with pH, organic carbon (OC) and available P was observed in the one of the sites studied. Overall assessment of the data indicated that season and location significantly affected the interaction of AM fungi with winter wheat necessitating the further need to understand the ecology of AMF populations with reference to specific host species under different micro-climatic conditions of Bundelkhand region.

  18. Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants.

    Science.gov (United States)

    Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A; Abd Allah, Elsayed F; Alqarawi, A A; Alyemeni, Mohammed N; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones. PMID:27458462

  19. Interação entre fungos micorrízicos arbusculares e bactérias diazotróficas em trigo Interaction between arbuscular mycorrhizal fungi and diazotrophic bacteria in wheat plants

    Directory of Open Access Journals (Sweden)

    Valéria Marino Rodrigues Sala

    2007-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da inoculação de dois novos isolados de bactérias diazotróficas endofíticas e da interação destas bactérias com fungos micorrízicos arbusculares (FMAs, na cultura do trigo. Foi realizado um experimento em casa de vegetação, com dois isolados de bactérias diazotróficas endofíticas, IAC11HT (Achromobacter insolitus e IAC12HT (Zoogloea ramigera, e dois FMAs (Glomus sp. e Acaulospora sp.. Houve efeito sinérgico da co-inoculação na colonização das raízes por bactérias diazotróficas, com o emprego do FMA do gênero Acaulospora. As plantas associadas a Glomus, na presença dos isolados bacterianos, apresentaram maior crescimento, acúmulo e aproveitamento dos nutrientes do que as plantas colonizadas por Acaulospora sp., entretanto, não superaram os tratamentos em que as bactérias e os fungos foram inoculados isoladamente. Apesar de não ter havido efeito benéfico da co-inoculação FMA-bactéria diazotrófica sobre a maioria dos parâmetros avaliados, essas novas bactérias propiciaram o dobro de crescimento, acúmulo e aproveitamento do N e P em plantas de trigo.The aim of this work was to evaluate the inoculation effect of two new endophytic diazotrophic bacteria and the interaction between arbuscular mycorrhizal fungi (AMF and these bacteria on wheat plants. The experiment was carried out in a greenhouse with the two strains of diazotrophic bacteria, IAC11HT (Achromobacter insolitus and IAC12HT (Zoogloea ramigera, and two AMF (Glomus sp. and Acaulospora sp.. There was synergistic effect of the co-inoculation on root colonization by diazotrophic bacteria with the AMF of the genus Acaulospora. The plants colonized by Glomus associated to bacterial strains showed higher growth, accumulation and exploitation of the nutrients than plants colonized by Acaulospora sp., however, this effect did not surpass the treatments in which bacteria and fungi were inoculated separately. Although

  20. Induction of Osmoregulation and Modulation of Salt Stress in Acacia gerrardii Benth. by Arbuscular Mycorrhizal Fungi and Bacillus subtilis (BERA 71)

    Science.gov (United States)

    Hashem, Abeer; Alqarawi, A. A.; Al-Huqail, A. A.; Shah, M. A.

    2016-01-01

    The role of soil microbiota in plant stress management, though speculated a lot, is still far from being completely understood. We conducted a greenhouse experiment to examine synergistic impact of plant growth promoting rhizobacterium, Bacillus subtilis (BERA 71), and arbuscular mycorrhizal fungi (AMF) (Claroideoglomus etunicatum; Rhizophagus intraradices; and Funneliformis mosseae) to induce acquired systemic resistance in Talh tree (Acacia gerrardii Benth.) against adverse impact of salt stress. Compared to the control, the BERA 71 treatment significantly enhanced root colonization intensity by AMF, in both presence and absence of salt. We also found positive synergistic interaction between B. subtilis and AMF vis-a-vis improvement in the nutritional value in terms of increase in total lipids, phenols, and fiber content. The AMF and BERA 71 inoculated plants showed increased content of osmoprotectants such as glycine, betaine, and proline, though lipid peroxidation was reduced probably as a mechanism of salt tolerance. Furthermore, the application of bioinoculants to Talh tree turned out to be potentially beneficial in ameliorating the deleterious impact of salinity on plant metabolism, probably by modulating the osmoregulatory system (glycine betaine, proline, and phenols) and antioxidant enzymes system (SOD, CAT, POD, GR, APX, DHAR, MDAHR, and GSNOR). PMID:27597969

  1. Induction of Osmoregulation and Modulation of Salt Stress in Acacia gerrardii Benth. by Arbuscular Mycorrhizal Fungi and Bacillus subtilis (BERA 71

    Directory of Open Access Journals (Sweden)

    Abeer Hashem

    2016-01-01

    Full Text Available The role of soil microbiota in plant stress management, though speculated a lot, is still far from being completely understood. We conducted a greenhouse experiment to examine synergistic impact of plant growth promoting rhizobacterium, Bacillus subtilis (BERA 71, and arbuscular mycorrhizal fungi (AMF (Claroideoglomus etunicatum; Rhizophagus intraradices; and Funneliformis mosseae to induce acquired systemic resistance in Talh tree (Acacia gerrardii Benth. against adverse impact of salt stress. Compared to the control, the BERA 71 treatment significantly enhanced root colonization intensity by AMF, in both presence and absence of salt. We also found positive synergistic interaction between B. subtilis and AMF vis-a-vis improvement in the nutritional value in terms of increase in total lipids, phenols, and fiber content. The AMF and BERA 71 inoculated plants showed increased content of osmoprotectants such as glycine, betaine, and proline, though lipid peroxidation was reduced probably as a mechanism of salt tolerance. Furthermore, the application of bioinoculants to Talh tree turned out to be potentially beneficial in ameliorating the deleterious impact of salinity on plant metabolism, probably by modulating the osmoregulatory system (glycine betaine, proline, and phenols and antioxidant enzymes system (SOD, CAT, POD, GR, APX, DHAR, MDAHR, and GSNOR.

  2. Influence of habitat and climate variables on arbuscular mycorrhizal fungus community distribution, as revealed by a case study of facultative plant epiphytism under semiarid conditions.

    Science.gov (United States)

    Torrecillas, E; Torres, P; Alguacil, M M; Querejeta, J I; Roldán, A

    2013-12-01

    In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.

  3. Induction of Osmoregulation and Modulation of Salt Stress in Acacia gerrardii Benth. by Arbuscular Mycorrhizal Fungi and Bacillus subtilis (BERA 71).

    Science.gov (United States)

    Hashem, Abeer; Abd Allah, E F; Alqarawi, A A; Al-Huqail, A A; Shah, M A

    2016-01-01

    The role of soil microbiota in plant stress management, though speculated a lot, is still far from being completely understood. We conducted a greenhouse experiment to examine synergistic impact of plant growth promoting rhizobacterium, Bacillus subtilis (BERA 71), and arbuscular mycorrhizal fungi (AMF) (Claroideoglomus etunicatum; Rhizophagus intraradices; and Funneliformis mosseae) to induce acquired systemic resistance in Talh tree (Acacia gerrardii Benth.) against adverse impact of salt stress. Compared to the control, the BERA 71 treatment significantly enhanced root colonization intensity by AMF, in both presence and absence of salt. We also found positive synergistic interaction between B. subtilis and AMF vis-a-vis improvement in the nutritional value in terms of increase in total lipids, phenols, and fiber content. The AMF and BERA 71 inoculated plants showed increased content of osmoprotectants such as glycine, betaine, and proline, though lipid peroxidation was reduced probably as a mechanism of salt tolerance. Furthermore, the application of bioinoculants to Talh tree turned out to be potentially beneficial in ameliorating the deleterious impact of salinity on plant metabolism, probably by modulating the osmoregulatory system (glycine betaine, proline, and phenols) and antioxidant enzymes system (SOD, CAT, POD, GR, APX, DHAR, MDAHR, and GSNOR). PMID:27597969

  4. Effect of ryegrass (Lolium perenne L.) roots inoculation using different arbuscular mycorrhizal fungi (AMF) species on sorption of iron-cyanide (Fe-CN) complexes

    Science.gov (United States)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2016-04-01

    Soils and groundwater on sites of the former Manufactured Gas Plants (MGPs) are contaminated with various complex iron-cyanides (Fe-CN). Phytoremediation is a promising tool in stabilization and remediation of Fe-CN affected soils, however, it can be a challenging task due to extreme adverse and toxic conditions. Phytoremediation may be enhanced via rhizosphere microbial activity, which can cooperate on the degradation, transformation and uptake of the contaminants. Recently, increasing number of scientist reports improved plants performance in the removal of toxic compounds with the support of arbuscular mycorrhizae fungi (AMF). Series of batch experiments using potassium hexacyanoferrate (II) solutions, in varying concentrations, were used to study the effect of ryegrass roots (Lolium perenne L.) inoculation with Rhizophagus irregularis and a mixture of Rhizophagus irregularis, Funneliformis mosseae, Rhizophagus aggregatus, and Claroideoglomus etunicatum on Fe-CN sorption. Results indicated significantly higher colonization of R. irregularis than for the mixture of AMF species on ryegrass roots. Sorption experiments revealed significantly higher reduction of total CN and free CN content in the mycorrhizal roots, indicating greater cyanide decrease in the treatment inoculated with R. irregularis. Our study indicates contribution of AM fungi in phytoremediation of Fe-CN contaminated soil.

  5. Organic and mineral fertilization, respectively, increase and decrease the development of external mycelium of arbuscular mycorrhizal fungi in a long-term field experiment.

    Science.gov (United States)

    Gryndler, M; Larsen, J; Hrselová, H; Rezácová, V; Gryndlerová, H; Kubát, J

    2006-05-01

    Effects of long-term mineral fertilization and manuring on the biomass of arbuscular mycorrhizal fungi (AMF) were studied in a field experiment. Mineral fertilization reduced the growth of AMF, as estimated using both measurements of hyphal length and the signature fatty acid 16:1omega5, whereas manuring alone increased the growth of AMF. The results of AMF root colonization followed the same pattern as AMF hyphal length in soil samples, but not AMF spore densities, which increased with increasing mineral and organic fertilization. AMF spore counts and concentration of 16:1omega5 in soil did not correlate positively, suggesting that a significant portion of spores found in soil samples was dead. AMF hyphal length was not correlated with whole cell fatty acid (WCFA) 18:2omega6,9 levels, a biomarker of saprotrophic fungi, indicating that visual measurements of the AMF mycelium were not distorted by erroneous involvement of hyphae of saprotrophs. Our observations indicate that the measurement of WCFAs in soil is a useful research tool for providing information in the characterization of soil microflora.

  6. Arbuscular mycorrhizal fungus enhances P acquisition of wheat (Triticum aestivum L.) in a sandy loam soil with long-term inorganic fertilization regime.

    Science.gov (United States)

    Hu, Junli; Lin, Xiangui; Wang, Junhua; Cui, Xiangchao; Dai, Jue; Chu, Haiyan; Zhang, Jiabao

    2010-10-01

    The P efficiency, crop yield, and response of wheat to arbuscular mycorrhizal fungus (AMF) Glomus caledonium were tested in an experimental field with long-term (19 years) fertilizer management. The experiment included five fertilizer treatments: organic amendment (OA), half organic amendment plus half mineral fertilizer (1/2 OM), mineral fertilizer NPK, mineral fertilizer NK, and the control (without fertilization). AMF inoculation responsiveness (MIR) of wheat plants at acquiring P were estimated by comparing plants grown in unsterilized soil inoculated with G. caledonium and in untreated soil containing indigenous AMF. Without AMF inoculation, higher crop yields but lower colonization rates were observed in the NPK and two OA-inputted treatments, and NPK had significantly (P soils and thereby P acquisition of wheat plants compared with OA and 1/2 OM. G. caledonium inoculation significantly (P soil alkaline phosphatase (ALP) activity, only with the NPK treatment. This gave an MIR of ca. 45% on total P acquisition of wheat plants. There were no other remarkable MIRs. It suggested that the MIR is determined by soil available P status, and rational combination of AMF with chemical NPK fertilizer can compensate for organic amendments by improving P-acquisition efficiency in arable soils.

  7. Growth, respiration and nutrient acquisition by the arbuscular mycorrhizal fungus Glomus mosseae and its host plant Plantago lanceolata in cooled soil.

    Science.gov (United States)

    Karasawa, T; Hodge, A; Fitter, A H

    2012-04-01

    Although plant phosphate uptake is reduced by low soil temperature, arbuscular mycorrhizal (AM) fungi are responsible for P uptake in many plants. We investigated growth and carbon allocation of the AM fungus Glomus mosseae and a host plant (Plantago lanceolata) under reduced soil temperature. Plants were grown in compartmented microcosm units to determine the impact on both fungus and roots of a constant 2.7 °C reduction in soil temperature for 16 d. C allocation was measured using two (13)CO(2) pulse labels. Although root growth was reduced by cooling, AM colonization, growth and respiration of the extraradical mycelium (ERM) and allocation of assimilated (13)C to the ERM were all unaffected; the frequency of arbuscules increased. In contrast, root respiration and (13)C content and plant P and Zn content were all reduced by cooling. Cooling had less effect on N and K, and none on Ca and Mg content. The AM fungus G. mosseae was more able to sustain activity in cooled soil than were the roots of P. lanceolata, and so enhanced plant P content under a realistic degree of soil cooling that reduced plant growth. AM fungi may therefore be an effective means to promote plant nutrition under low soil temperatures.

  8. Crescimento de mudas de maracujazeiro-doce (Passiflora alata Curtis associadas a fungos micorrízicos arbusculares (Glomeromycota Growth of seedlings of sweet-passion fruit (Passiflora alata Curtis associated to arbuscular mycorrhizal fungi (Glomeromycota

    Directory of Open Access Journals (Sweden)

    Maryluce Albuquerque da Silva

    2004-12-01

    Full Text Available Para determinar o efeito de fungos micorrízicos arbusculares sobre o crescimento de mudas de maracujazeiro-doce foi conduzido, em casa de vegetação, experimento com delineamento inteiramente casualizado usando cinco tratamentos de inoculação (200 esporos/planta de Acaulospora longula Spain & Schenck, Gigaspora albida Schenck & Smith, Glomus etunicatum Becker & Gerd., Scutellospora heterogama (Nicol. & Gerd. Walker & Sanders e controle não inoculado, com sete repetições. A cada 20 dias foram avaliados altura e número de folhas e ao final do experimento (90 dias: diâmetro do caule, biomassa, área foliar, colonização micorrízica e densidade de esporos de FMA na rizosfera. A partir de 70 dias foram evidenciadas diferenças no número de folhas; aos 90 dias as plantas inoculadas com G. albida apresentaram maior altura que as demais, que não diferiram significativamente entre si. Plantas associadas com esse fungo apresentaram, em relação ao controle, incrementos de 2.138% e 1.430% nas biomassas fresca e seca da parte aérea, 1.937% na biomassa fresca da raiz e 2.671% na área foliar. Apesar de não existir especificidade de hospedeiro na associação micorrízica arbuscular, apenas G. albida promoveu respostas significativas no maracujazeiro-doce, indicando a existência de maior compatibilidade funcional entre esses simbiontes.In order to determine the effect of arbuscular mycorrhizal fungi (AMF on growth of seedlings of sweet-yellow passion fruit, a greenhouse experiment was performed, using 200 AMF spores/plant in a randomized design with five treatments of inoculation (Acaulospora longula Spain & Schenck, Gigaspora albida Schenck & Smith, Glomus etunicatum Becker & Gerd., Scutellospora heterogama (Nicol. & Gerd. Walker & Sanders, and a non inoculated control with seven replicates. Every 20 days height and leaf number and after 90 days shoot diameter, biomass, leaf area, root colonization and density of AMF spores in the

  9. Sodium Chloride Stress Induced Changes in Leaf Osmotic Adjustment of Trifoliate Orange (Poncirus trifoliata Seedlings Inoculated with Mycorrhizal Fungi

    Directory of Open Access Journals (Sweden)

    Ying-Ning ZOU

    2011-11-01

    Full Text Available Citrus plants are sensitive to salinity, and thus employing new approaches to alleviate salt damage are necessary. The present study evaluated the effect of two arbuscular mycorrhizal fungi (AMF, Glomus mosseae and G. versiforme, on leaf osmotic adjustment of trifoliate orange (Poncirus trifoliata seedings exposed to 100 mM NaCl. Salinity significantly inhibited mycorrhizal colonization, plant biomass and leaf relative water content, whereas the reduce of plant biomass was notably alleviated by the mycorrhizal colonization. Mycorrhizal seedlings exhibited significantly lower Na+ and Ca2+ concentrations, whilst also recorded higher K+ concentration and K+/Na+, Ca2+/Na+ and Mg2+/Na+ ratios at both salinity levels. Under salinity stress, mycorrhizal symbiosis markedly decreased sucrose concentrations of leaves and also increased glucose, fructose and proline concentrations of leaves. The results suggest that arbuscular mycorrhizas improved leaf osmotic adjustment responses of the seedlings to salt stress, thus enhancing salt tolerance of mycorrhizal plants.

  10. Arbuscular mycorrhizas and ectomycorrhizas of Uapaca bojeri L. (Euphorbiaceae) : sporophore diversity, patterns of root colonization, and effects on seedling growth and soil microbial catabolic diversity

    OpenAIRE

    Ramanankierana, N.; Ducousso, M.; Rakotoarimanga, N.; Prin, Y.; Thioulouse, J.; Randrianjohany, E.; Ramaroson, L.; Kisa, Marija; Galiana, A; Duponnois, Robin

    2007-01-01

    The main objectives of this study were (1) to describe the diversity of mycorrhizal fungal communities associated with Uapaca bojeri, an endemic Euphorbiaceae of Madagascar, and (2) to determine the potential benefits of inoculation with mycorrhizal fungi [ectomycorrhizal and/or arbuscular mycorrhizal (AM) fungi] on the growth of this tree species and on the functional diversity of soil microflora. Ninety-four sporophores were collected from three survey sites. They were identified as belongi...

  11. Fungos micorrízicos arbusculares na formação de mudas de cafeeiro, em substratos orgânicos comerciais Arbuscular mycorrhizal fungi on the development of coffee plantlets using different organic substrates

    Directory of Open Access Journals (Sweden)

    Fabrício Sales Massafera Tristão

    2006-01-01

    Full Text Available Realizou-se um experimento, em casa de vegetação, em arranjo fatorial 9 x 4, com o objetivo de avaliar o efeito de substratos orgânicos comerciais e inoculação de fungos micorrízicos arbusculares (FMAs no desenvolvimento de mudas de cafeeiro, cultivar 'Catuaí Amarelo', IAC 62. Utilizaram-se substratos à base de fibra de coco (Golden Mix 11, Golden Mix 47 e Golden Mix 80, casca de pinus (Rendmax, Vida Verde com adubação, Vida Verde sem adubação e Terra do Paraíso, solo puro e solo + esterco (70% e 30%,v/v, inoculando-se os FMAs Glomus intraradices, Glomus etunicatum e Gigaspora margarita. Manteve-se um tratamento sem inoculação. Aos 200 dias após transplante avaliaram-se: altura, diâmetro do caule, número de folhas, matéria seca da parte aérea, matéria fresca da raiz, teor de fósforo na parte aérea, colonização radicular, comprimento do micélio externo, atividade da fosfatase ácida e teores de pigmentos fotossintetizantes nas folhas do cafeeiro. Independentemente da micorrização, o melhor crescimento das mudas foi obtido no substrato Vida Verde sem adubação. Os melhores efeitos da micorrização foram constatados nas plantas colonizadas por G. margarita e crescidas nos substratos convencional (solo + esterco e Vida Verde com adubação, nas quais se verificaram mais eficácia na utilização de P, o que reverteu em maior crescimento e produção de biomassa, resultando em maior eficiência simbiótica. No substrato solo + esterco, a micorrização favoreceu a concentração de pigmentos fotossintetizantes e diminuiu a atividade da fosfatase ácida nas folhas do cafeeiro.A greenhouse experiment with an alleatory factorial 9 x 4 scheme was carried out to evaluate the effects of different substrates and species of arbuscular mycorrhizal fungi (AMF on the development of coffee plants, cultivar Catuaí Amarelo, IAC 62. Nine substrates were used: seven commercial organic substrates - four substrates containing composted

  12. The Inhibitory Effect of Rhododendron maximum L. (Ericaceae) Thickets on Mycorrhizal Colonization of Canopy Tree Seedlings

    OpenAIRE

    Walker, John F.

    1998-01-01

    THE INHIBITORY EFFECT OF RHODODENDRON MAXIMUM L. (ERICACEAE) THICKETS ON MYCORRHIZAL COLONIZATION OF CANOPY TREE SEEDLINGS John F. Walker (ABSTRACT) Thickets of Rhododendron maximum (Rm) in the southern Appalachians impose severe limitations on the regeneration of hardwood and coniferous seedlings. Interactions between Rm thickets and ectomycorrhizal colonization were examined to explain seedling inhibition. Experimental blocks were established in and out of Rm thickets in a mature,...

  13. The role of carbon in fungal nutrient uptake and transport: implications for resource exchange in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Fellbaum, Carl R; Mensah, Jerry A; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2012-11-01

    The arbuscular mycorrhizal (AM) symbiosis, which forms between plant hosts and ubiquitous soil fungi of the phylum Glomeromycota, plays a key role for the nutrient uptake of the majority of land plants, including many economically important crop species. AM fungi take up nutrients from the soil and exchange them for photosynthetically fixed carbon from the host. While our understanding of the exact mechanisms controlling carbon and nutrient exchange is still limited, we recently demonstrated that (i) carbon acts as an important trigger for fungal N uptake and transport, (ii) the fungus changes its strategy in response to an exogenous supply of carbon, and that (iii) both plants and fungi reciprocally reward resources to those partners providing more benefit. Here, we summarize recent research findings and discuss the implications of these results for fungal and plant control of resource exchange in the AM symbiosis.

  14. Arbuscular mycorrhizal fungi in phytoremediation of contaminated areas by trace elements: mechanisms and major benefits of their applications.

    Science.gov (United States)

    Cabral, Lucélia; Soares, Claúdio Roberto Fonsêca Sousa; Giachini, Admir José; Siqueira, José Oswaldo

    2015-11-01

    In recent decades, the concentration of trace elements has increased in soil and water, mainly by industrialization and urbanization. Recovery of contaminated areas is generally complex. In that respect, microorganisms can be of vital importance by making significant contributions towards the establishment of plants and the stabilization of impacted areas. Among the available strategies for environmental recovery, bioremediation and phytoremediation outstand. Arbuscular mycorrhizal fungi (AMF) are considered the most important type of mycorrhizae for phytoremediation. AMF have broad occurrence in contaminated soils, and evidences suggest they improve plant tolerance to excess of certain trace elements. In this review, the use of AMF in phytoremediation and mechanisms involved in their trace element tolerance are discussed. Additionally, we present some techniques used to study the retention of trace elements by AMF, as well as a summary of studies showing major benefits of AMF for phytoremediation.

  15. In vivo 31 P NMR Spectroscopy for the study of P Pools and their Dynamics in Arbuscular Mycorrhizal Fungi

    DEFF Research Database (Denmark)

    Viereck, Nanna

    The main objective of the studies described in the present P1i.D. thesis was to investigate the phospbate (P) metabolism of arbuscular mycorrhizal (AM) fungi by in viv0 31P nuclear magnetic resonance (NMR) spectroscopy. P is an essential nutrient for all organisms. It is required in relatively...... of AM fungi used included Scutellospora caloJpora, G. mosseae and Gigaspora rosea. The cucumber plants were grown in a central mesh-bag, which prevents root penetration but allow free passage of AM fungal hyphae. Tbe extraradical mycelium grew into sand surrounding the mesh-bag and could be collected...... from the sand, while root matenal could be collected from the mesh-bag. A circulation system was constructed for oxygenating the excised hyphae or roots while in the NMR tube. Both the efficiency of P, uptake and the turn-over of P metabolites by excised hyphae were investigated in order to clarify the...

  16. Effect of Arbuscular Mycorrhizal Fungi On Yield and Phytoremediation Performance of Pot Marigold (Calendula officinalis L.) Under Heavy Metals Stress.

    Science.gov (United States)

    Tabrizi, Leila; Mohammadi, Siavash; Delshad, Mojtaba; Moteshare Zadeh, Babak

    2015-01-01

    In order to study the effect of mycorrhizal fungi (inoculated and non-inoculated) and heavy metals stress [0, Pb (150 and 300 mg/kg) and Cd (40 and 80 mg/kg)] on pot marigold (Calendula officinalis L.), a factorial experiment was conducted based on a randomized complete block design with 4 replications in Research Greenhouse of Department of Horticultural Sciences, University of Tehran, Iran, during 2012-2013. Plant height, herbal and flower fresh and dry weight, root fresh and dry weight and root volume, colonization percentage, total petal extract, total petal flavonoids, root and shoot P and K uptakes, and Pb and Cd accumulations in root and shoot were measured. Results indicated that with increasing soil Pb and Cd concentration, growth and yield of pot marigold was reduced significantly; Cd had greater negative impacts than Pb. However, mycorrhizal fungi alleviated these impacts by improving plant growth and yield. Pot marigold concentrated high amounts of Pb and especially Cd in its roots and shoots; mycorrhizal plants had a greater accumulation of these metals, so that those under 80 mg/kg Cd soil(-1) accumulated 833.3 and 1585.8 mg Cd in their shoots and roots, respectively. In conclusion, mycorrhizal fungi can improve not only growth and yield of pot marigold in heavy metal stressed condition, but also phytoremediation performance by increasing heavy metals accumulation in the plant organs. PMID:26237494

  17. Effects of biochar amendment and arbuscular mycorrhizal fungi inoculation on availability of soil phosphorus and growth of maize

    Directory of Open Access Journals (Sweden)

    A.E. Mau

    2014-01-01

    Full Text Available A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF inoculation on phosphorus uptake by maize (Zea mayze L. grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil were arranged in a completely randomized block design with three replicates. Results of the study showed that at 8 weeks after transplanting, the biochar and mycorrhizal treatments increased the availability soil phosphorus and phosphorus uptake by maize. Application 4.5 and 7.5 g biochar/kg of soil combined with inoculation of 10-15 AMF spores / kg of soil provided to high value of phosphorus uptake by maize. Application of biochar alone, however, did not significantly improve maize growth and phosphorus uptake by maize

  18. Effects of biochar amendment and arbuscular mycorrhizal fungi inoculation on availability of soil phosphorus and growth of maize

    Directory of Open Access Journals (Sweden)

    A.E. Mau

    2014-01-01

    Full Text Available A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF inoculation on phosphorus uptake by maize (Zea mayze L. grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil were arranged in a completely randomized block design with three replicates. Results of the study showed that at 8 weeks after transplanting, the biochar and mycorrhizal treatments increased the availability soil phosphorus and phosphorus uptake by maize. Application 4.5 and 7.5 g biochar/kg of soil combined with inoculation of 10-15 AMF spores / kg of soil provided to high value of phosphorus uptake by maize. Application of biochar alone, however, did not significantly improve maize growth and phosphorus uptake by maize.

  19. Effect of chromium contaminated soil on arbuscular mycorrhizal colonisation of roots and metal uptake by Plantago lanceolata

    Energy Technology Data Exchange (ETDEWEB)

    Estaun, V.; Cortes, A.; Velianos, K.; Camprubi, A.; Calvet, C.

    2010-07-01

    Industrial practices are the primary causes for the accumulation of chromium in the environment, an element considered as a toxic heavy metal when present in high concentrations. The beneficial contribution of arbuscular mycorrhizal fungi (AMF) to plant nutrition and growth has been acknowledged, however, results of heavy metal uptake by plants under mycorrhizal symbiosis vary. The AMF Glomus intraradices (BEG 72) was used with Plantago lanceolata as a host plant in three experiments. In the first one, devised to assess the plant tolerance to Cr(III) in the soil, four levels of chromium concentration were applied in a sterile soil mix, placed in pots with inoculated and non inoculated plant treatments. Plant survival, shoot weight and AMF root colonisation were measured. In the second experiment which was designed in order to determine the effect of the symbiosis on the chromium uptake, similar treatments were used, and in addition, the heavy metal plant tissue content was measured and the bioconcentration factors calculated. In the third experiment the chromium uptake from an industrial chromium waste contaminated soil was assessed using treatments with and without the AMF. Results showed that chromium has a severe impact on the survival of non inoculated plants, however, plants inoculated with AMF in moderately contaminated soil, perform in terms of growth and survival rate, as well as the non inoculated plants in soil with no chromium added, suggesting a buffering effect of the AMF by decreased intake of the toxic element in the roots and its translocation to the shoot. (Author) 28 refs.

  20. Plant potassium content modifies the effects of arbuscular mycorrhizal symbiosis on root hydraulic properties in maize plants.

    Science.gov (United States)

    El-Mesbahi, Mohamed Najib; Azcón, Rosario; Ruiz-Lozano, Juan Manuel; Aroca, Ricardo

    2012-10-01

    It is well known that the arbuscular mycorrhizal (AM) symbiosis helps the host plant to overcome several abiotic stresses including drought. One of the mechanisms for this drought tolerance enhancement is the higher water uptake capacity of the mycorrhizal plants. However, the effects of the AM symbiosis on processes regulating root hydraulic properties of the host plant, such as root hydraulic conductivity and plasma membrane aquaporin gene expression, and protein abundance, are not well defined. Since it is known that K(+) status is modified by AM and that it regulates root hydraulic properties, it has been tested how plant K(+) status could modify the effects of the symbiosis on root hydraulic conductivity and plasma membrane aquaporin gene expression and protein abundance, using maize (Zea mays L.) plants and Glomus intraradices as a model. It was observed that the supply of extra K(+) increased root hydraulic conductivity only in AM plants. Also, the different pattern of plasma membrane aquaporin gene expression and protein abundance between AM and non-AM plants changed with the application of extra K(+). Thus, plant K(+) status could be one of the causes of the different observed effects of the AM symbiosis on root hydraulic properties. The present study also highlights the critical importance of AM fungal aquaporins in regulating root hydraulic properties of the host plant. PMID:22370879

  1. Extraradical development and contribution to plant performance of an arbuscular mycorrhizal symbiosis exposed to complete or partial rootzone drying.

    Science.gov (United States)

    Neumann, Elke; Schmid, Barbara; Römheld, Volker; George, Eckhard

    2009-11-01

    Sweet potato plants were grown with or without Glomus intraradices in split-root pots with adjacent root compartments containing a soil with a low availability of phosphate. One fungal tube, from which root growth was excluded, was inserted into each root compartment. During 4 weeks before harvest, the soil moisture level in either both or only one of the two root-compartments of each pot was decreased. Controls remained well watered. Low soil moisture generally had a negative effect on the amount of extraradical mycelium of G. intraradices extracted from the fungal tubes. Sporulation in the fungal tubes was much higher compared with the soil in the root compartment, but remained unaffected by the soil moisture regime. Concentrations of P in extraradical mycelium were much lower than usually found in plants and fungi, while P concentrations in associated mycorrhizal host plant tissues were in an optimum range. This suggests efficient transfer of P from the extraradical mycelium to the host plant. Despite the negative effect of a low soil moisture regime on extraradical G. intraradices development, the symbiosis indeed contributed significantly to P uptake of plants exposed to partial rootzone drying. The possibility that extraradical arbuscular mycorrhizal fungal development was limited by P availability under dry soil conditions is discussed. PMID:19499252

  2. Behavior of decabromodiphenyl ether (BDE-209) in soil: Effects of rhizosphere and mycorrhizal colonization of ryegrass roots

    International Nuclear Information System (INIS)

    A rhizobox experiment was conducted to investigate degradation of decabromodiphenyl ether (BDE-209) in the rhizosphere of ryegrass and the influence of root colonization with an arbuscular mycorrhizal (AM) fungus. BDE-209 dissipation in soil varied with its proximity to the roots and was enhanced by AM inoculation. A negative correlation (P 2 = 0.66) was found between the residual BDE-209 concentration in soil and soil microbial biomass estimated as the total phospholipid fatty acids, suggesting a contribution of microbial degradation to BDE-209 dissipation. Twelve and twenty-four lower brominated PBDEs were detected in soil and plant samples, respectively, with a higher proportion of di- through hepta-BDE congeners in the plant tissues than in the soils, indicating the occurrence of BDE-209 debromination in the soil-plant system. AM inoculation increased the levels of lower brominated PBDEs in ryegrass. These results provide important information about the behavior of BDE-209 in the soil-plant system. - Research highlights: → BDE-209 dissipation in soil was affected by the proximity to the roots. → Microbial degradation contributes greatly to BDE-209 dissipation in the soil. → Twelve and twenty-four lower brominated PBDEs were detected in soil and plant samples. → AM inoculation increased root uptake and accumulation of BDE-209. - BDE-209 dissipation and degradation in soil were affected by both its proximity to ryegrass roots and inoculation with an AM fungus.

  3. Seasonality and mycorrhizal colonization in three species of epiphytic orchids in southeast Mexico

    Directory of Open Access Journals (Sweden)

    Vincenzo Bertolini

    2014-12-01

    Full Text Available Orchids establish symbiosis with Rhizoctonia mycorrhizal fungi, forming the characteristic pelotons within the cells of the root cortex. Under natural conditions, terrestrial and epiphytic orchids have different levels of dependence upon the fungal symbiont, although various authors have mentioned that once orchid plants reach maturity the interaction becomes weaker and intermittent. Recent evidence shows that in some epiphytic orchid species mycorrhization is constant and systematic. In three species of wild orchids from southeast Mexico, we show that mycorrhization is systematically present in roots of different ages, in the wet and dry seasons. We demonstrate that the volume of the root that is colonized depends upon the quantity of rainfall and the diameter of the root, and that rainfall also determines the presence of fresh, undigested pelotons. In very thin roots, mycorrhizal colonization occupies a considerable proportion of the cortex, whereas in thicker roots the proportion of the volume of the root cortex colonized is lower.

  4. Phosphate concentration and arbuscular mycorrhizal colonisation influence the growth, yield and expression of twelve PHT1 family phosphate transporters in foxtail millet (Setaria italica)

    OpenAIRE

    Antony Ceasar, S.; Angela Hodge; Alison Baker; Baldwin, Stephen A.

    2014-01-01

    Phosphorus (P) is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet) is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S. italica to different levels of inorganic phosphate (Pi) and to colonisation with the arbuscular mycorrhizal fungus Funneliformis mosseae (syn. Glomus mosseae) were studied. Phosphat...

  5. Differences in Arbuscular Mycorrhizal Fungal Community Composition in Soils of Three Land Use Types in Subtropical Hilly Area of Southern China

    OpenAIRE

    Wang, Caihuan; Gu, Zhenhong; Cui, Hang; Zhu, Honghui; Fu, Shenlei; Yao, Qing

    2015-01-01

    Land use type is key factor in restoring the degraded soils due to its impact on soil chemical properties and microbial community. In this study, the influences of land use type on arbuscular mycorrhizal fungal (AMF) community and soil chemical properties were assessed in a long-run experimental station in subtropical hilly area of southern China. Soil samples were collected from forest land, orchard and vegetable field. Soil chemical properties were analyzed, and PCR-DGGE was performed to ex...

  6. The Effects of Arbuscular Mycorrhizal Fungus (AMF) and Humic Acid on the Growth of Pepper (Capsicum annuum L.) Plant and Root Rot Disease Caused by Phytophthora capsici Leonian

    OpenAIRE

    ASLANPAY, Burcu; Semra DEMİR

    2015-01-01

    In this study, the effects of singular and double combinations of Arbuscular Mycorrhizal Fungi (AMF) and humic acid (HA) were investigated on the growth of pepper (Capsicum annuum L.) and rot root disease caused by Phytophthora capsici Leonian which has been known as an important problem of pepper cultivation and leading yield losses. Under controlled conditions, four F1 pepper cultivars (Ergenekon, Bafra, Sirena and Yıldız) were inoculated with three different AMF strains (Glomus intraradice...

  7. The bifunctional plant receptor, OsCERK1, regulates both chitin-triggered immunity and arbuscular mycorrhizal symbiosis in rice.

    Science.gov (United States)

    Miyata, Kana; Kozaki, Toshinori; Kouzai, Yusuke; Ozawa, Kenjirou; Ishii, Kazuo; Asamizu, Erika; Okabe, Yoshihiro; Umehara, Yosuke; Miyamoto, Ayano; Kobae, Yoshihiro; Akiyama, Kohki; Kaku, Hanae; Nishizawa, Yoko; Shibuya, Naoto; Nakagawa, Tomomi

    2014-11-01

    Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes. PMID:25231970

  8. Leaf δ15N as an indicator of arbuscular mycorrhizal nitrogen uptake in a coastal-plain forest (restinga forest) at Southeastern Brazil

    Science.gov (United States)

    Mardegan, S. F.; Valadares, R.; Martinelli, L.

    2013-12-01

    Restinga diversity contrasts with a series of adverse environmental conditions that constrain their development, including nutrient limitation. In this sense, the mutualistic symbiosis between plants and arbuscular mycorrhizal fungi (AMF) may contribute in nutrient acquisition, including nitrogen. However, this association deeply affects plant nitrogen isotopic composition (δ15N), since assimilation processes and biochemical reactions within the fungi may reflect in a delivered product with an isotopic composition about 8 to 10 ‰ lower than that observed at the fungal symbiont per se. Here we assessed if the association with AMF affects δ15N values of plant species from a coastal-plain forest (restinga forest) at Southeastern Brazil. Accordingly, we analyzed the nutritional and isotopic compositions from ecosystem key-compartments (soil, litter and leaves), relating plant δ15N with the colonization rates. The study was carried out in a permanent plot (1 ha) at a coastal-plain forest (restinga forest) at the Serra do Mar State Park, SP, Brazil. Sampled vegetation is characterized by the lack of a well-defined stratification and a rather open canopy. It also comprises trees ranging from 10 to 15-m high. Soils are deep and sandy, being characterized by high acidity, nutrient deficiency and a dense litter cover. We randomly collected five samples (250 mg) from topsoil (0-10 cm) and five to ten leaves from individuals belonging to 16 plant species of high relevance within the site (IVI index). We also collected superficial (0-10 cm depth) fine roots (5 g) and 13 samples (100 g) of fine litter next to the individuals sampled. Soil samples were air-dried, sieved, homogenized and used in the physical-chemical characterization. The remainder was ground to a fine powder to determine nitrogen concentrations and δ15N values. Leaves were dried at 50 °C, finely milled and used for the determination of nitrogen concentrations, C/N ratios and δ15N values. Root samples were

  9. Diversity and Seasonal Variation of Arbuscular Mycorrhizal Fungi in Spiraea pubescens%土庄绣线菊AMF多样性及季节变化分析∗

    Institute of Scientific and Technical Information of China (English)

    朱艳育; 峥嵘; 段国珍; 邵东华; 王琚钢; 白淑兰

    2016-01-01

    In order to explore the arbuscular mycorrhizal fungi diversity and seasonal variation in rhizosphere of S. pubescens in Daqingshan Mountain, Inner Mongolia, China, rhizosphere soil samples were collected in spring, summer and autumn of 2014, respectively. AMF spores were separated with wet-sieving and decanting technique and identified by the morphological methods. The results indicated that the intensity of mycorrhizal colonization, the abundance of arbuscule, the spore density and the species abundance had significant differences between differ-ent seasons, and the maximum values of these four indexes were found in the summer, but the minimums were de-tected at spring. 44 AMF species belonging to 10 genera and 2 unidentified species were isolated from all soil sam-ples, the dominant genera of 3 seasons were Rhizophagus, Funneliformis and Glomus. R. intraradices and F. mosseae were the dominant species of 3 seasons. Abundance, Shannon index and Simpson index had significantly negative correlation with total Nitrogen and available Phosphorus, while they had were significantly positive correla-tion with available potassium. Abundance had negatively correlated with pH, and it had significantly positively correlated with alkaline Nitrogen. The seasonal variation of AMF in rhizosphere of S. pubescens was consistent with plant phenology, and closely related to soil factors.%为探讨内蒙古大青山土庄绣线菊根围丛枝菌根真菌( arbuscular mycorrhizal fungi, AMF)多样性及季节变化规律,分别于2014年春、夏、秋3个季节采集土庄绣线菊根际土壤,采用湿筛倾析-蔗糖离心法分离AMF孢子,运用形态学方法进行种类鉴定。结果表明, AMF侵染强度、丛枝丰富度、孢子密度、种的丰富度的季节变化存在显著的差异,4个指标均显示夏季最高,秋季次之,春季最低。3个季节共分离出AMF10属44种,包括2个未知种,其中 Rhizophagus、 Funneliformis和Glomus为3

  10. SOIL CHEMICAL PROPERTIES AND GROWTH OF SUNFLOWER (HELIANTHUS ANNUUS L. AS AFFECTED BY THE APPLICATION OF ORGANIC FERTILIZERS AND INOCULATION WITH ARBUSCULAR MYCORRHIZAL FUNGI

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    Apolino José Nogueira da Silva

    2015-02-01

    Full Text Available The use of organic fertilizers and the inoculation of mycorrhizal fungi in the cultivation of oil crops is essential to reduce production costs and minimize negative impacts on natural resources. A field experiment was conducted in an Argissolo Amarelo (Ultisol with the aim of evaluating the effects of fertilizer application and inoculation of arbuscular mycorrhizal fungi on the growth attributes of sunflower (Helianthus annuus L. and on soil chemical properties. The experiment was conducted at the Federal University of Rio Grande do Norte, Brazil, using a randomized block design with three replicates in a 4 × 2 factorial arrangement consisting of four treatments in regard to application of organic fertilizer (liquid biofertilizer, cow urine, mineral fertilizer, and unfertilized control and two treatments in regard to arbuscular mycorrhizal fungi (with and without mycorrhizal fungi. The results showed that the physiological attributes of relative growth rate and leaf weight ratio were positively influenced by fertilization, compared to the control treatment, likely brought about by the supply of nutrients from the fertilizers applied. The growth and productivity attributes were positively affected by mycorrhization.

  11. Entrophospora schenckii and Pacispora franciscana, arbuscular mycorrhizal fungi (Glomeromycota new for Europe and Poland, respectively

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    Janusz Błaszkowski

    2014-08-01

    Full Text Available Morphological properties of spores of Pacispora franciscana, as well as spores and mycorrhizae of Entrophospora schenckii, arbuscular fungi of the phylum Glomeromycota found for the first time in Poland and Europe, respectively, are described and illustrated. Additionally, the known distribution of the two fungi is presented.

  12. Suppression of the biocontrol agent trichoderma harzianum by mycelium of the arbuscular mycorrhizal fungus glomus intraradices in root-free soil

    Science.gov (United States)

    Green; Larsen; Olsson; Jensen; Jakobsen

    1999-04-01

    Trichoderma harzianum is an effective biocontrol agent against several fungal soilborne plant pathogens. However, possible adverse effects of this fungus on arbuscular mycorrhizal fungi might be a drawback in its use in plant protection. The objective of the present work was to examine the interaction between Glomus intraradices and T. harzianum in soil. The use of a compartmented growth system with root-free soil compartments enabled us to study fungal interactions without the interfering effects of roots. Growth of the fungi was monitored by measuring hyphal length and population densities, while specific fatty acid signatures were used as indicators of living fungal biomass. Hyphal 33P transport and beta-glucuronidase (GUS) activity were used to monitor activity of G. intraradices and a GUS-transformed strain of T. harzianum, respectively. As growth and metabolism of T. harzianum are requirements for antagonism, the impact of wheat bran, added as an organic nutrient source for T. harzianum, was investigated. The presence of T. harzianum in root-free soil reduced root colonization by G. intraradices. The external hyphal length density of G. intraradices was reduced by the presence of T. harzianum in combination with wheat bran, but the living hyphal biomass, measured as the content of a membrane fatty acid, was not reduced. Hyphal 33P transport by G. intraradices also was not affected by T. harzianum. This suggests that T. harzianum exploited the dead mycelium but not the living biomass of G. intraradices. The presence of external mycelium of G. intraradices suppressed T. harzianum population development and GUS activity. Stimulation of the hyphal biomass of G. intraradices by organic amendment suggests that nutrient competition is a likely means of interaction. In conclusion, it seemed that growth of and phosphorus uptake by the external mycelium of G. intraradices were not affected by the antagonistic fungus T. harzianum; in contrast, T. harzianum was adversely

  13. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    Science.gov (United States)

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  14. Microarray analysis and functional tests suggest the involvement of expansins in the early stages of symbiosis of the arbuscular mycorrhizal fungus Glomus intraradices on tomato (Solanum lycopersicum).

    Science.gov (United States)

    Dermatsev, Vladimir; Weingarten-Baror, Carmiya; Resnick, Nathalie; Gadkar, Vijay; Wininger, Smadar; Kolotilin, Igor; Mayzlish-Gati, Einav; Zilberstein, Avia; Koltai, Hinanit; Kapulnik, Yoram

    2010-01-01

    Arbuscular mycorrhizal (AM) symbiosis occurs between fungi of the phylum Glomeromycota and most terrestrial plants. However, little is known about the molecular symbiotic signalling between AM fungi (AMFs) and non-leguminous plant species. We sought to further elucidate the molecular events occurring in tomato, a non-leguminous host plant, during the early, pre-symbiotic stage of AM symbiosis, i.e. immediately before and after contact between the AMF (Glomus intraradices) and the host. We adopted a semi-synchronized AMF root infection protocol, followed by genomic-scale, microarray-based, gene expression profiling at several defined time points during pre-symbiotic AM stages. The microarray results suggested differences in the number of differentially expressed genes and in the differential regulation of several functional groups of genes at the different time points examined. The microarray results were validated and one of the genes induced during contact between AMF and tomato, the expansin-like EXLB1, was functionally analysed. Expansins, encoded by a large multigene family, facilitate plant cell expansion. However, no biological or biochemical function has yet been established for plant-originated expansin-like proteins. EXLB1 transcripts were localized early during the association to cells that may perceive the fungal signal, and later during the association in close proximity to sites of AMF hypha-root colonization. Moreover, in transgenic roots, we demonstrated that a reduction in the steady-state level of EXLB1 transcript was correlated with a reduced rate of infection, reduced arbuscule expansion and reduced AMF spore formation.

  15. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    Science.gov (United States)

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p < 0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  16. Efeito da mobilização do solo nas micorrizas arbusculares de cereais de Inverno Effects of soil management on arbuscular mycorrhizal fungi in autumn-sown crops

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    I. Brito

    2007-01-01

    sua capacidade para gerar novas colonizações no período cultural. Com o objectivo de avaliar a diversidade dos Glomeromycota presentes no campo de ensaios em estudo, sujeito aos dois tipos de mobilização do solo (SD e MT, foi usada a técnica de amplificação de sequências de rDNA destes fungos a partir de DNA total do solo. Esta técnica permite uma avaliação abrangente, evitando a morosidade e complexidade da abordagem clássica através de culturas armadilha. No total foram analisadas 87 sequencias, provenientes de solo perturbado e não perturbado, e encontrados 11 tipos ribosomais. Considerando as diferenças de frequência dos tipos ribosomais presentes em cada tipo de solo, os resultados parecem confirmar que os fungos micorrízicos arbusculares são diferencialmente susceptíveis à perturbação do solo, não só em termos de diversidade como ao nível da estrutura da comunidade.Soil tillage may markedly reduce the rate of arbuscular mycorrhiza (AM establishment by breaking up the living AM fungal mycelium in the soil. In no till or reduced till management, this mycelium can allow earlier AM formation. Work under field conditions in a Mediterranean climate clearly confirmed that wheat plants cultivated under no-till system had a 6 fold greater mycorrhizal colonization than those grown using a conventional tillage system. Pot experiments were initiated to determine the benefit of the timing of colonization on plants. Soil disturbance induced by tillage practices was simulated by passing the soil through a 4 mm sieve at the start of each successive period of 3 weeks plant growth cycles. After 4 cycles of plant growth (wheat, significant effects in all colonization parameters were detected. Arbuscular, vesicular and hyphal colonization were clearly higher in undisturbed soil. To gain a global overview of the diversity of Glomeromycota under the 2 cultivation systems in the experimental field, rDNA sequences from the fungi have been amplified

  17. Effect of arbuscular mycorrhizal fungal inoculation in combination with different organic fertilizers on maize crop in eroded soils

    International Nuclear Information System (INIS)

    A pot experiment was conducted to study the effect of inoculating maize (Zea mays L. Azam) with Arbuscular mycorrhizal (AM) fungi in 2 different series of North West Pakistan during the year 2007. Data showed significant increase in shoots and roots yield of maize with the inoculation of AM fungi alone and in combination with farm yard manure (FYM), poultry manure (PM) and humic acid (HA) over control and N-P-K treatments. Accumulation of N by maize shoots increased significantly by the addition of HA, PM and FYM plus N-P-K with or without inoculation of AM fungi over the treatments of N-P-K and control. Plants P accumulation increased significantly over control and N-P-K treatments with the inoculation of AM fungi alone and in combination with FYM, PM and HA in missa soil series. In missa gullied soil series, significantly increased plants P accumulation was noted by the treatments of AM inoculation with PM followed by HA. Accumulation of Mn by maize shoots increased significantly with AM inoculation with HA and PM over all other treatments, Fe increased with PM, HA and FYM. Plants Cu accumulation in missa series increased significantly over control and N-P-K treatments by AM alone and in combination with PM, FYM and HA and by AM fungi with PM, FYM and HA in missa gullied series. Maximum Mycorrhizal root infection rate of 51 % was recorded in the treatment of AM fungal inoculation with HA followed by the treatment inoculated with AM fungi with FYM. In missa gullied soil series, Maximum (59 %) and significantly increased roots infection rates over all treatments were observed in the treatment of AM fungal inoculation with HA followed by PM. Spores concentrations of AM fungi increased significantly with AM inoculation alone and with FYM, PM and HA. Maximum spores numbers of 50 in 20 g soil were recorded by the inoculation of AM fungi alone and with HA. (author)

  18. Constitutive overexpression of the sucrose transporter SoSUT1 in potato plants increases arbuscular mycorrhiza fungal root colonization under high, but not under low, soil phosphorus availability.

    Science.gov (United States)

    Gabriel-Neumann, Elke; Neumann, Günter; Leggewie, Georg; George, Eckhard

    2011-06-15

    The sucrose transporter SUT1 functions in phloem loading of photoassimilates in solanaceous plant species. In the present study, wildtype and transgenic potato plants with either constitutive overexpression or antisense inhibition of SUT1 were grown under high or low phosphorus (P) fertilization levels in the presence or absence of the arbuscular mycorrhizal (AM) fungus Glomus intraradices. At a low soil P fertilization level, the extent of AM fungal root colonization was not different among the genotypes. In all plants, the AM symbiosis contributed significantly to P uptake under these conditions. In response to a high soil P fertilization level, all genotypes showed a decrease in AM fungal root colonization, indicating that the expression level of SUT1 does not constitute a major mechanism of control over AM development in response to the soil P availability. However, plants with overexpression of SUT1 showed a higher extent of AM fungal root colonization compared with the other genotypes when the soil P availability was high. Whether an increased symbiotic C supply, alterations in the phytohormonal balance, or a decreased synthesis of antimicrobial compounds was the major cause for this effect requires further investigation. In plants with impaired phloem loading, a low C status of plant sink tissues did apparently not negatively affect plant C supply to the AM symbiosis. It is possible that, at least during vegetative and early generative growth, source rather than sink tissues exert control over amounts of C supplied to AM fungi. PMID:21382646

  19. Interação entre fungos micorrízicos arbusculares e fósforo no desenvolvimento da algaroba [Prosopis juliflora (Sw DC] Interaction between arbuscular mycorrhizal fungi and phosphorus on growth of Prosopis juliflora (Sw DC

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    Regina Lúcia Félix de Aguiar

    2004-08-01

    Full Text Available Acompanhou-se, durante 100 dias, o desenvolvimento de mudas de algaroba (Prosopis juliflora (Sw DC em relação à presença ou ausência de fungos micorrízicos arbusculares (FMA, nativos ou introduzidos, combinada com adição ou não de fósforo ao solo. Foi usado solo Podzólico Vermelho-Amarelo com pH ácido (4,7 e 2 mg.dm-3 de solo de P extraível por resina. O experimento teve delineamento inteiramente casualizado em arranjo fatorial com duas condições de solo (esterilizado ou não, três níveis de fósforo (acréscimo de 0, 50 e 100 kg de P.ha-1 e duas condições de inoculação (inoculado ou não, com quatro repetições. No solo não esterilizado, apenas o diâmetro do colo respondeu à inoculação com esporos de FMA, quando foi usada a dose P100; o aumento de altura, número de folhas e massa seca foi possivelmente devido à adição de fósforo ao solo. No solo esterilizado, a inoculação resultou no aumento de altura, número de folhas, diâmetro de colo e massa seca das mudas na presença ou na ausência de P (P0 e P50, em relação àquelas no solo não-inoculado. Com o aumento da dose de fósforo (P100, os benefícios da inoculação não foram mais verificados, sendo a colonização e a produção de esporos favorecidas pela adição de P ao solo. Prosopis juliflora foi considerada micotrófica facultativa, pois respondeu tanto à inoculação com FMA quanto à adição de fósforo.The effect of arbuscular mycorrhizal fungi (AMF and addition of phosphorus on seedling growth of Prosopis juliflora in sterilized and unsterilized soils was followed during 100 days. A red-yellow podzolic soil, pH of 4.7 and 2 mg Pdm-3, was used. The experiment was carried in a completely randomized design, with four replicates, and factorial arrangement of 2 soil conditions (sterilized and unsterilized × 3 P levels (0, 50 and 100 kg P.ha-1 × 2 mycorrhizal treatments (with and without AMF. In unsterilized soil, only the collar diameter

  20. Effect of Arbuscular Mycorrhizal Fungi Glomus spp. Inoculation on Alfalfa Growth in Soils with Copper Efecto de la Inoculación con Hongos Micorrízicos Arbusculares Glomus spp. sobre el Crecimiento de Alfalfa en Suelos con Cobre

    Directory of Open Access Journals (Sweden)

    Daniela Novoa M

    2010-06-01

    Full Text Available Soils near mining centers usually have high heavy metal (HM levels. It has been found that some plants associated with arbuscular mycorrhizal fungi (AMF improve growth and tolerance to HM in soils. This symbiosis is a biological resource for degraded soil recovery. The objective of this study was to determine the effect of inoculating AMF (Glomus spp. on alfalfa (Medicago sativa L. growth in agricultural soils with different copper (Cu levels for degraded soil recovery. To this effect, alfalfa seeds were grown in soils from the Catemu and Casablanca valleys and inoculated with AMF. Plant height, stem diameter, and number of leaves were measured weekly. Dry matter, mycorrhizal colonization, and Cu concentration in alfalfa plant tissues were measured after 81 days. Inoculation increased plant height by 24%, stem diameter by 11%, and number of leaves by 34%. Inoculation had a significant effect (p ≤ 0.05 on alfalfa plants that were grown in soil with the highest Cu concentration, but had no effect on Cu accumulation in alfalfa plant tissues. A direct relationship was observed between Cu accumulation in alfalfa and Cu concentration in soils. It was concluded that alfalfa inoculated with Glomus spp. is applicable to the soil recovery process whenever soil properties can ensure inoculum effectiveness on alfalfa growth, and avoid toxicity by excessive Cu in alfalfa plant tissues.Los suelos cercanos a centros de actividad minera suelen presentar altos niveles de metales pesados (HM. Se ha encontrado que algunas plantas asociadas a hongos micorrízicos arbusculares (AMF mejoran su crecimiento y tolerancia a los HM presentes en los suelos. Esta simbiosis constituye un recurso biológico para la recuperación de suelos degradados. El objetivo de este estudio fue determinar el efecto de la inoculación con AMF (Glomus spp. sobre el crecimiento de alfalfa (Medicago sativa L. en suelos agrícolas con distintos niveles de cobre (Cu para la recuperación de

  1. Ocorrência de bactérias diazotróficas e fungos micorrízicos arbusculares na cultura da mandioca Occurrence of diazotrophic bacteria and arbuscular mycorrhizal fungi on the cassava crop

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    1999-07-01

    Full Text Available Este trabalho teve como objetivo avaliar a ocorrência, isolar e identificar fungos micorrízicos arbusculares associados à cultura da mandioca (Manihot esculenta. Amostras de solo rizosférico e de várias partes da planta (raízes, tubérculos, manivas e folhas de locais nos Estados do Rio de Janeiro, São Paulo e Paraná, foram inoculadas nos meios LGI-P, NFb-malato e NFb-GOC, avaliando-se o número mais provável de células e a atividade de redução de acetileno. Bactérias diazotróficas foram isoladas de todas as partes da planta, com exceção das folhas, sendo identificadas como Klebsiella sp., Azospirillum lipoferum e uma bactéria denominada "E", provavelmente pertencente ao gênero Burkholderia. A Bactéria E acumulou de 7,63 mg a 14,84 mg de N/g de C em meio semi-sólido, isento de N, e conseguiu manter a capacidade de fixação biológica de N, mesmo após uma dezena de repicagens consecutivas. A colonização micorrízica variou de 31% a 69%, e a densidade de esporos de 10 a 384 esporos/100 mL de solo, predominando as espécies Entrophospora colombiana e Acaulospora scrobiculata no Rio de Janeiro, A. scrobiculata e Scutellospora heterogama no Paraná e em Piracicaba (São Paulo e A. appendicula e S. pellucida em Campinas (São Paulo.This study was performed to evaluate the occurrence and to isolate and identify diazotrophic bacteria and arbuscular mycorrhizal fungi associated with the cassava (Manihot esculenta crop. Samples from rhizospherical soil, roots, tubers, stems and leaves from several localities of the States of Rio de Janeiro, São Paulo and Paraná, in Brazil, were inoculated in three media specific for diazotrophic associative bacteria, LGI-P, NFb-malate and NFb-GOC, evaluating the most probable number of cells and the acetylene-reducing activity. Diazotrophic bacteria were detected in all plant parts except for the leaves, and were identified as Klebsiella sp., Azospirillum lipoferum and a bacterium called "E

  2. Comunidades de fungos micorrízicos arbusculares associados ao amendoim forrageiro em pastagens consorciadas no Estado do Acre, Brasil Communities of arbuscular mycorrhizal fungi associated with peanut forage in mixed pastures in the state of Acre, Brazil

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    Elias Melo de Miranda

    2010-03-01

    Full Text Available O objetivo deste trabalho foi identificar e estimar a diversidade de comunidades de fungos micorrízicos arbusculares (FMAs autóctones associados ao amendoim forrageiro (Arachis pintoi, em monocultivo e consorciado com outras forrageiras. A amostragem foi realizada em sete áreas, em Rio Branco, AC, sendo coletadas quatro amostras de solo em cada área, na profundidade de 0-10 cm, nas estações seca (junho de 2004 e chuvosa (janeiro de 2005. As áreas cultivadas com A. pintoi foram: monocultivo, consórcio com pastagens de gramíneas e outras leguminosas e como cobertura do solo em cafeeiro, além de capoeira e mata adjacentes como testemunhas. Foi verificada a ocorrência de 21 espécies de FMAs nas duas estações, sendo 18 espécies no período seco e 16 no chuvoso. As espécies foram distribuídas em cinco gêneros: Acaulospora, Entrophospora, Gigaspora, Glomus e Scutellospora. A densidade de esporos foi maior no consórcio A. pintoi x Brachiaria brizantha x Pueraria phaseoloides e a menor nas áreas de A. pintoi x cafeeiro, capoeira e mata. As colonizações radiculares foram maiores na estação chuvosa (15 a 63% do que na estação seca (5 a 37%. Os índices de diversidade no monocultivo foram semelhantes aos das demais áreas avaliadas, indicando que o amendoim serve como hospedeiro de diferentes espécies de FMAs e que o seu cultivo pode aumentar a presença desses organismos nos sistemas produtivos, melhorando a qualidade biológica do solo.The purpose of this study was to identify the autochthonous communities of arbuscular mycorrhizal fungi (AMF associated with Arachis pintoi and estimate its diversity. Samples of soil were collected in a Field at Rio Branco, AC. The sampling was carried out in seven areas, being collected four samples from soil in each area, in a depth of 0-10cm, in dry season (June 2004 and rainy season (January 2005. The areas cultivated with A. pintoi were: monoculture, grass pasture and others legumes

  3. Mycorrhizal and dark septate endophytic fungi under the canopies of desert plants in Mu Us Sandy Land of China

    Institute of Scientific and Technical Information of China (English)

    Yanqing WU; Tiantian LIU; Xueli HE

    2009-01-01

    Biodiversity of arbuscular mycorrhizal colonization and spore density was investigated in 20 desert plants (dominant or common species) collected from different locations of Mu Us Sandy Land of China. We observed three mycorrhizal types including Arum-type, Paris-type, and an intermediate type among the plants. Another type of potentially beneficial fungi associated with roots of all species was also observed, namely, dark septate endophytic fungi (DSEF). Of the 20 sample plants examined, all species were coinfected by the two target fungi (Arbuscular mycorrhizal fungi (AMF) colonization of Salixpsammophila and DSEF colonization of Periploca septum were as low as 4%). Based on this investigation, we speculated that the DSEF are ubiquitous in desert ecosystems and can co-occur with AMF in desert plants, functioning much like mycorrhizal fungi. Further studies will be required to elucidate interactional mechanisms with AMF and the mechanisms operating in desert ecosystem.

  4. Uso de vermicomposto favorece o crescimento de mudas de gravioleira (Annona muricata L. 'Morada' associadas a fungos micorrízicos arbusculares Use of earthworm manure improves growth of soursop seedlings (Annona muricata L. 'Morada' associated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Danielle Karla Alves da Silva

    2008-09-01

    melhorar a qualidade do solo, contribuindo para a produção sustentável de mudas desta e de outras fruteiras.Annona muricata L. (soursop easily adapts to irrigation in the semiarid Northeast. The economically important fruits have high exportation potential, so production has been encouraged. The use of organic amendments, together with arbuscular mycorrhizal fungi (AMF may be useful for production of seedlings. However, the effect of such amendments on the symbiosis established between AMF and soursop remains unknown. The effect of AMF multiplied in a substrate with earthworm manure on the formation of A. muricata seedlings maintained in fertilized substrate was investigated. The experimental design was entirely random, in a factorial of 2×5 = 2 substrates (with or without 10% organic manure and five inoculation treatments (Acaulospora longula Spain & Schenck and Gigaspora albida Schenck & Smith, produced in substrates with or without organic residue and an uninoculated control, with four replicates. After 102 days, dry mass of shoots and roots, height, growth rate, production of AMF spores and glomalin, soil enzymatic activity, microbial respiration, total, arbuscular and hyphal colonization were evaluated. In general, seedling growth was stimulated by the inoculation with AMF, but in the fertilized soil, growth of seedlings in symbiosis with G. albida was not benefited. The use of organic fertilizer stimulated mycorrhizal colonization, microbial respiration, enzymatic activity and glomalin production, but inhibited A. longula sporulation. The application of AMF and organic manure may constitute an alternative for production of Annona muricata, since it reduced by half the period for seedling formation, and can reduce by 75% the dose of fertilizer to be applied. However, the choice of AMF compatible with the host is needed to assure positive results. The combination of both, AMF and organic amendment, can also improve soil quality, thus contributing to sustainable

  5. Arbuscular mycorrhizal fungal communities along a pedo-hydrological gradient in a Central Amazonian terra firme forest.

    Science.gov (United States)

    de Oliveira Freitas, Rejane; Buscardo, Erika; Nagy, Laszlo; dos Santos Maciel, Alex Bruno; Carrenho, Rosilaine; Luizão, Regina C C

    2014-01-01

    Little attention has been paid to plant mutualistic interactions in the Amazon rainforest, and the general pattern of occurrence and diversity of arbuscular mycorrhizal fungi (AMF) in these ecosystems is largely unknown. This study investigated AMF communities through their spores in soil in a 'terra firme forest' in Central Amazonia. The contribution played by abiotic factors and plant host species identity in regulating the composition, abundance and diversity of such communities along a topographic gradient with different soils and hydrology was also evaluated. Forty-one spore morphotypes were observed with species belonging to the genera Glomus and Acaulospora, representing 44 % of the total taxa. Soil texture and moisture, together with host identity, were predominant factors responsible for shaping AMF communities along the pedo-hydrological gradient. However, the variability within AMF communities was largely associated with shifts in the relative abundance of spores rather than changes in species composition, confirming that common AMF species are widely distributed in plant communities and all plants recruited into the forest are likely to be exposed to the dominant sporulating AMF species. PMID:23754540

  6. Arbuscular mycorrhizal fungal communities and soil aggregation as affected by cultivation of various crops during the sugarcane fallow period

    Directory of Open Access Journals (Sweden)

    Priscila Viviane Truber

    2014-04-01

    Full Text Available Management systems involving crop rotation, ground cover species and reduced soil tillage can improve the soil physical and biological properties and reduce degradation. The primary purpose of this study was to assess the effect of various crops grown during the sugarcane fallow period on the production of glomalin and arbuscular mycorrhizal fungi in two Latosols, as well as their influence on soil aggregation. The experiment was conducted on an eutroferric Red Latosol with high-clay texture (680 g clay kg-1 and an acric Red Latosol with clayey texture (440 g kg-1 clay in Jaboticabal (São Paulo State, Brazil. A randomized block design involving five blocks and four crops [soybean (S, soybean/fallow/soybean (SFS, soybean/millet/soybean (SMS and soybean/sunn hemp/soybean (SHS] was used to this end. Soil samples for analysis were collected in June 2011. No significant differences in total glomalin production were detected between the soils after the different crops. However, total external mycelium length was greater in the soils under SMS and SHS. Also, there were differences in easily extractable glomalin, total glomalin and aggregate stability, which were all greater in the eutroferric Red Latosol than in the acric Red Latosol. None of the cover crops planted in the fallow period of sugarcane improved aggregate stability in either Latosol.

  7. Petroleum hydrocarbon contamination, plant identity and arbuscular mycorrhizal fungal (AMF) community determine assemblages of the AMF spore-associated microbes.

    Science.gov (United States)

    Iffis, Bachir; St-Arnaud, Marc; Hijri, Mohamed

    2016-09-01

    The root-associated microbiome is a key determinant of pollutant degradation, soil nutrient availability and plant biomass productivity, but could not be examined in depth prior to recent advances in high-throughput sequencing. Arbuscular mycorrhizal fungi (AMF) form symbioses with the majority of vascular plants. They are known to enhance mineral uptake and promote plant growth and are postulated to influence the processes involved in phytoremediation. Amplicon sequencing approaches have previously shown that petroleum hydrocarbon pollutant (PHP) concentration strongly influences AMF community structure in in situ phytoremediation experiments. We examined how AMF communities and their spore-associated microbiomes were structured within the rhizosphere of three plant species growing spontaneously in three distinct waste decantation basins of a former petrochemical plant. Our results show that the AMF community was only affected by PHP concentrations, while the AMF-associated fungal and bacterial communities were significantly affected by both PHP concentrations and plant species identity. We also found that some AMF taxa were either positively or negatively correlated with some fungal and bacterial groups. Our results suggest that in addition to PHP concentrations and plant species identity, AMF community composition may also shape the community structure of bacteria and fungi associated with AMF spores.

  8. Petroleum hydrocarbon contamination, plant identity and arbuscular mycorrhizal fungal (AMF) community determine assemblages of the AMF spore-associated microbes.

    Science.gov (United States)

    Iffis, Bachir; St-Arnaud, Marc; Hijri, Mohamed

    2016-09-01

    The root-associated microbiome is a key determinant of pollutant degradation, soil nutrient availability and plant biomass productivity, but could not be examined in depth prior to recent advances in high-throughput sequencing. Arbuscular mycorrhizal fungi (AMF) form symbioses with the majority of vascular plants. They are known to enhance mineral uptake and promote plant growth and are postulated to influence the processes involved in phytoremediation. Amplicon sequencing approaches have previously shown that petroleum hydrocarbon pollutant (PHP) concentration strongly influences AMF community structure in in situ phytoremediation experiments. We examined how AMF communities and their spore-associated microbiomes were structured within the rhizosphere of three plant species growing spontaneously in three disti