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Sample records for vesicular-arbuscular mycorrhizal development

  1. Effect of vesicular arbuscular mycorrhizal fungus on the ...

    African Journals Online (AJOL)

    The symbiotic association between certain plants and microorganisms plays an important role in soil fertilization, and improves their growth and mineral nutrition. The symbiotic association between vesicular arbuscular mycorrhizal (VAM) fungi and roots provides a significant contribution to plant nutrition and growth.

  2. The vesicular-arbuscular mycorrhizal symbiosis | Quilambo | African ...

    African Journals Online (AJOL)

    Vesicular-arbuscular mycorrhiza fungi are associated with the majority ot the terrestrial plants. Their function ranges from stress alleviation to bioremediation in soils polluted with heavy metals. However, our knowledge about this symbiosis is still limited. For the semi-arid tropics, where some african countries are located, ...

  3. 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...

  4. The development and significance of vesicular-arbuscular mycorrhizas as influenced by agricultural practices

    NARCIS (Netherlands)

    Ruissen, M.A.

    1982-01-01

    The development and significance of vesicular- arbuscular mycorrhizas (VAM) in wheat and potatoes have been studied in relation to various farming systems and agricultural practices. The effects of farming systems on VAM have been observed on three neighbouring experimental farms in the vicinity of

  5. Arbuscules of vesicular-arbuscular mycorrhizal fungi inhabit an acidic compartment within plant roots.

    Science.gov (United States)

    Guttenberger, M

    2000-08-01

    The most widespread type of mycorrhiza is the so-called vesicular-arbuscular mycorrhiza. In this endomycorrhiza, fungal hyphae penetrate plant cell walls in the root cortex. There they form densely branched arbuscules. Fungus and plant plasma membrane are separated by a common interfacial apoplast. The pH of the compartment between the symbionts is of pivotal importance for nutrient transfer. Histochemical experiments were conducted to check for an acidic nature of the interface in the model system Glomus versiforme (Karst.) Berch-Allium porrum L. Two chemically different acidotropic dyes (neutral red and LysoSensor Green DND-189) stained the arbuscules intensely. The staining of arbuscules could be eliminated by addition of the protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) or treatments leading to membrane rupture. Therefore, the staining of the arbuscules was based on the ion-trap mechanism, which indicates acidic, membrane-bound compartments. Microscopic examination of stained arbuscules at high optical resolution revealed a peripheral accumulation of the dye. Since plasmolysis rapidly destained the arbuscules, it is concluded that the dyes accumulate in the arbuscular interface, indicating the highly acidic nature of this compartment. The findings are discussed with respect to their relevance for the nutrient transfer in mycorrhizas. In addition, evidence for a discontinuity in the arbuscular interface between the stem and the branches of the arbuscule is given.

  6. Vesicular-Arbuscular Mycorrhiza in Field-Grown Crops. I. Mycorrhizal Infection in Cereals and Peas at Various Times and Soil Depths

    DEFF Research Database (Denmark)

    Jakobsen, Iver; Nielsen, N.E.

    1983-01-01

    Development of infection by vesicular-arbuscular mycorrhiza (VAM) was studied in some field-grown crops. An infection plateau was reached within the first month after seedling emergence of spring barley, oats and peas. During the rest of the growth period the proportion of root length infected...

  7. The beneficial effect of dual inoculation of vesicular-arbuscular mycorrhizae + rhizobium on growth of white clover

    Directory of Open Access Journals (Sweden)

    Lin, XG.

    1993-01-01

    Full Text Available Investigation on the effect of phosphorus on vesicular-arbuscular mycorrhizal infection, and dual inoculation of vesicular-arbuscular mycorrhizae + rhizobium on growth of white clover under field microplots and pot experiments was conducted on fluvo-aquic soils of semi-arid region in north China. The results showed that 60 kg P205 ha in form of superphosphate was the most favorable phosphorus level for vesicular-arbuscular mycorrhizal infection ; mycorrhizal infection, nodulation, dry weight of shoots and roots, total uptake of nitrogen, phosphorus and other elements, the final yields and recovery of phosphorus of white clover were significantly increased by vesicular-arbuscular mycorrhizal inoculation and dual inoculation with vesicular-arbuscular mycorrhizal fungi and rhizobium. The highest response of inoculation was obtained by adding fertilizer phosphorus at the level of 60 kg P205 ha in form of superphosphate.

  8. Vesicular-Arbuscular Mycorrhiza in Field-Grown Crops

    DEFF Research Database (Denmark)

    Jakobsen, Iver

    1986-01-01

    The importance of vesicular-arbuscular mycorrhiza (VAM) and P fertilizer for P nutrition and dry matter production in field peas (Pisum sativum L.) was studied in moderately P-deficient soil. Half of the experimental plots were fumigated to reduce the level of VAM infection. Shoots and 0 to 30 cm...... in fumigated plots, although both it and P uptake were increased by adding P fertilizer. The possible reasons for this discrepancy are discussed. A supplementary survey on infection development at five other field sites showed that peas are extensively colonized by VAM fungi, even in soils where a standard...

  9. Factors influencing survival of vesicular-arbuscular mycorrhiza propagules during topsoil storage

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.M.; Carnes, B.A.; Moorman, T.B.

    1985-01-01

    The survival dynamics of vesicular-arbuscular mycorrhizal fungi were determined, (using a bioassay procedure) for soils stored from 0.5 to 6.0 years in topsoil stockpiles associated with a coal surface-mine in the western United States. Propagule mortality could best be related to in situ soil moisture potential using a piecewise regression model (R/sup 2/ = 0.57; P less than or equal to 0.001) with the breaking point occurring at -2 MPa. The addition of length of storage time was found to contribute significantly to the accuracy of the model (R/sup 2/ = 0.70; P less than or equal to 0.001). In addition, the piece-wise nature of the data suggested two separate populations of VAM fungi - those propagules found in soils with moisture potentials less than -2 MPa and those occurring in soils with moisture potentials greater than -2 MPa. Soil moisture and length of storage time had differing effects on each of these populations. When water potential was less than -2 MPa, moisture was an important predictor of inoculum (P < 0.001), while length of storage had little predictive capability (P = 0.17). However, when water potentials were greater than -2 MPa, the predictive importance of soil moisture (P = 0.86) and length of storage (P = 0.04) were reversed. The significance of these findings to topsoil replacement and subsequent plant community development are discussed. 28 references, 2 figures, 2 tables.

  10. Vesicular-arbuscular mycorrhiza response to crossed carbon and phosphorus resource gradients

    Energy Technology Data Exchange (ETDEWEB)

    Whitbeck, J.L. (Pennyslvania State Univ., University Park, PA (United States))

    1994-06-01

    Employing the annual herb Hemizonia luzulaefolia, native to nutrient limited grassland ecosystem in California, and a community of indigenous vesicular-arbuscular mycorrhizal (VAM) fungi, this study examined mycorrhizal response to interacting plant- and fungus-acquired resources. Plant carbon supply was manipulated through atmospheric carbon dioxide (CO[sub 2]) concentration, and substrate phosphorus (P) supply was varied in the nutrient solution. H. luzulaefolia responded strongly to VAM association, showing increased root and shoot biomass, greater leaf area, higher shoot P content and lower specific root length relative to non-mycorrhizal plants. Elevated (700 ppm) CO[sub 2] plants had lower mass, lower root:shoot ratios and slightly greater specific root length than ambient pCO[sub 2]-grown plants. VAM colonization of roots was stimulated by elevated CO[sub 2] early in the experiment. Low P plants showed greater leaf mass per area and lower shoot P concentration than plus-P plants. P effects on measures of VAM changed over time. While ambient pCO[sub 2]-grown plants responsed to added P with increased biomass, plants grown at elevated CO[sub 2] showed equivalent or lower biomass in plus-P treatments than in those with no added P. At the same time, ambient pCO[sub 2]-grown plants developed greater VAM colonization of roots in low P treatments, while at 700 ppm CO[sub 2]. VAM colonization was higher in plus-P treatments. It appears that atmospheric pCO[sub 2] affects the patterns of belowground allocation in H. luzulaefolia: ambient pCO[sub 2] plants direct carbon resources to VAM when P is low and to roots when P is available, while elevated CO[sub 2] plants maintain VAM colonization regardless of P environment and allocate to roots when P is low.

  11. Laboratory bioassay for assessing the effects of sludge supernatant on plant growth and vesicular-arbuscular mycorrhiza formation

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, K.S.; Liberta, A.E.

    1982-12-01

    A laboratory bioassay is described for assessing the effects of sludge supernatant on juvenile corn growth and the ability of vesicular-arbuscular (VA) mycorrhizal fungi, indigenous to coal spoil, to form mycorrhizae. The bioassay demonstrated that application rates can be identified that have the potential to promote increased plant dry weight without suppressing the formation of VA mycorrhizae in a plant's root system.

  12. Influence of vesicular arbuscular mycorrhiza (VAM) and phosphate ...

    African Journals Online (AJOL)

    A field experiment was carried out to find out the effect of biofertilizers, vesicular arbuscular mycorrhiza (VAM), and phosphate solubilising bacteria (PSB) individually and in combination on growth and physiological attributing properties of Marsdenia volubilis plant under nursery conditions. The plant seedlings were ...

  13. Seasonality of vesicular-arbuscular mycorrhizae in sedges in a semi-arid tropical grassland

    Science.gov (United States)

    Muthukumar, T.; Udaiyan, K.

    2002-10-01

    Vesicular-arbuscular mycorrhizal (VAM) colonization and spore numbers in the rhizosphere of Cyperus iria L. and C. rotundus L., growing in a semi-arid tropical grassland, was studied during the 1993 and 1994 monsoons. In addition, climatic and chemical properties of the soils were determined in order to investigate their influence on mycorrhizal variables. VAM fungal association in the sedges was confirmed by plant- and root-trap culture techniques. The soil nutrients exhibited seasonal variations, but were highly variable between years. Intercellular hyphae and vesicles with occasional intraradical spores characterized mycorrhizal association in sedges. Dark septate fungi also colonized roots of sedges. Temporal variations in mycorrhizal colonization and spore numbers occurred, indicating seasonality. However, the patterns of mycorrhizal colonization and spore numbers were different during both the years. The VAM fungal structures observed were intercellular hyphae and vesicles. Changes in the proportion of root length with VAM structures, total colonization levels and spore numbers were related to climatic and edaphic factors. However, the intensity of influence of climatic and soil factors on VAM tended to vary with sedge species.

  14. The vesicular-arbuscular mycorrhizal symbiosis | Quilambo | African ...

    African Journals Online (AJOL)

    African Journal of Biotechnology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 12 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should ...

  15. Effect of vesicular arbuscular mycorrhizal fungus on the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-06

    Oct 6, 2008 ... were estimated following the method of Dubois et al. (1956). The amount of nitrate formed was measured by the method of Cataldo et al. (1975). Estimation of praline was done according to Bates. (1973). The dried plant materials were ground in porcelain mortar with porcelain pestle and the N content was ...

  16. Vesicular-arbuscular-/ecto-mycorrhiza succession in seedlings of. Eucalyptus spp.

    Directory of Open Access Journals (Sweden)

    Santos Vera Lúcia dos

    2001-01-01

    Full Text Available The occurrence of vesicular-arbuscular mycorrhizae (AM and ectomycorrhizae (ECM in the same root system was observed when species of Eucalyptus urophylla S.T. Blake, E. citriodora Hook f., E. grandis W. Hill ex Maiden, E. cloeziana F. Muell. and E. camaldulensis Dehnh were simultaneously inoculated with Glomus etunicatum Becker & Gederman and Pisolithus tinctorius (Per. Cocker & Couch, isolate Pt 90A. The succession between the two fungi was observed. In general ectomycorrhizal colonization increased followed by a decrease in AM. Pisolithus tinctorius was favored in simultaneous inoculation with G. etunicatum, and the positive effect of the simultaneous inoculation of both fungi in the percent colonization by the AM fungus occurred up to 60 days after inoculation. After 120 days, colonization of roots by G. etunicatum decreased in the presence of P. tinctorius. When inoculated simultaneously, the proportion of AM and ECM varied with evaluation time, while the combined percentage of mycorrhizal roots approached the maximum and remained more or less constant after 60 days, suggesting that there could be competition between the fungi for limiting substrate. The maximum percent mycorrhizal colonization varied with Eucalyptus species and the highest value was observed for E. camaldulensis, followed in order by E. citriodora, E. urophylla, E. grandis and E. cloeziana.

  17. Survey of vesicular-arbuscular mycorrhizae in lettuce production in relation to management and soil factors

    Science.gov (United States)

    Miller, R.L.; Jackson, L.E.

    1998-01-01

    The occurrence of vesicular-arbuscular mycorrhizae (VAM) root colonization and spore number in soil was assessed for 18 fields under intensive lettuce (Lactuca sativa L.) production in California during July and August of 1995. Data on management practices and soil characteristics were compiled for each field, and included a wide range of conditions. The relationship between these factors and the occurrence of VAM in these fields was explored with multivariate statistical analysis. VAM colonization of lettuce tended to decrease with the use of chemical inputs, such as pesticides and high amounts of P and N fertilizers. Addition of soil organic matter amendments, the occurrence of other host crops in the rotation, and soil carbon:phosphorus and carbon:nitrogen ratios, were positively associated with VAM colonization of lettuce roots. The number of VAM spores in soil was strongly correlated with the number of other host crops in the rotation, the occurrence of weed hosts and sampling date, but was more affected by general soil conditions than by management inputs. Higher total soil N, C and P, as well as CEC, were inversely related to soil spore number. A glasshouse study of the two primary lettuce types sampled in the field showed no significant differences in the extent of root colonization under similar growing conditions. The results of this study are compared with other studies on the effects of management and soil conditions on mycorrhizal occurrence in agriculture.

  18. Comparison of vesicular-arbuscular mycorrhizae in plants from disturbed and adjacent undisturbed regions of a coastal salt marsh in Clinton, Connecticut, USA

    Science.gov (United States)

    Cooke, John C.; Lefor, Michael W.

    1990-01-01

    Roots of salt marsh plant species Spartina alterniflora, S. patens, Distichlis spicata, and others were examined for the presence of vesicular-arbuscular mycorrhizal (VAM) fungi. Samples were taken from introduced planted material in a salt marsh restoration project and from native material in adjacent marsh areas along the Indian River, Clinton, Connecticut, USA. After ten years the replanted area still has sites devoid of vegetation. The salt marsh plants introduced there were devoid of VAM fungi, while high marsh species from the adjacent undisturbed region showed consistent infection, leading the authors to suggest that VAM fungal infection of planting stocks may be a factor in the success of marsh restoration.

  19. NUTRIENT TRANSFER IN VESICULAR-ARBUSCULAR MYCORRHIZAS: A NEW MODEL BASED ON THE DISTRIBUTION OF ATPases ON FUNGAL AND PLANT MEMBRANES

    Directory of Open Access Journals (Sweden)

    S.E. SMITH

    1995-01-01

    Full Text Available In this paper we review the membrane transport processes that are involved in the transfer of mineral nutrients and organic carbon between the symbiotic partners in mycorrhizas. In particular, we reassess the prevailing hypothesis that transfer in vesicular-arbuscular (VA mycorrhizas occurs simultaneously and bidirectionally across the same interface and that arbuscules are the main sites of transfer. Using cytochemical techniques, we and our collaborators have reexamined the distribution of ATPases in the arbuscular and intercellular hyphal interfaces in VA mycorrhizas formed between roots ofAllium cepa (onion and the fungus Glomus intraradices. The results showed that H +-ATPases have different localisation on plant and fungal membranes in arbuscular and hyphal interfaces (Gianinazzi-Pearson et al. 1991. While some arbuscular interfaces had H+-ATPase activity on both fungal and plant membranes, in most cases the fungal membrane lacked this activity. In contrast, the plasma membranes of intercellular hyphae always had H + -ATPase and the adjacent root cells did not. This suggests that the different interfaces in a VA mycorrhiza may have different functions. We propose that passive loss of P from the arbuscules is associated with active uptake by the energised (ATPase-bearing plant membrane and that passive loss of carbohydrate from the root cells is followed by active uptake by the intercellular hyphae. If this model is correct, then variations in "mycorrhizal efficiency" (i.e. the extent to which mycorrhizal plants grow better than non-mycorrhizal controls might be determined by differences in the numbers of active arbuscules as a proportion of the total fungal biomass within the root. As a first step towards investigating this possibility, we have developed methods for measuring the surface areas of arbuscular and hyphal interfaces in different fungus-host combinations, Glomus spp./ Allium porrum (leek. We have also measured fluxes of P from

  20. The influence of vesicular-arbuscular mycorrhizas on production ...

    African Journals Online (AJOL)

    arbuscular mycorrhizas produced slight increases in dry mater production in unsterilized field plots at Cedara, Natal. Phosphorus levels in plant tops showed no increases due to mycorrhizas but crude protein content of all mycorrhizal plants were ...

  1. Vesicular-Arbuscular Mycorrhiza in Field-Grown Crops

    DEFF Research Database (Denmark)

    Jakobsen, Iver

    1983-01-01

    The effect of inoculation with vesicular–arbuscular mycorrhizal fungi on the growth of barley in the field was studied at two levels of soil P on plots fumigated with methyl bromide. During the vegetative phase, growth and P uptake was influenced only by soil P; P uptake in the period from earing...

  2. Effect of solarization and vesicular arbuscular mychorrizal on weed ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... determine VAM before testing in laboratory, VAM dutied like a bridge from donor lettuce to receiver wild mustard (Sinapsis ... Also the laboratory findings supported this; the number of spores, number of VAM infected and infection rate ..... Technics and usages of Mycorrhizal spor in agricultura. Cukurova.

  3. The Effects of Vesicular-Arbuscular Mycorrhizae on the Plant Growth and Nutrient Uptake of Cucumber

    OpenAIRE

    ÇIĞŞAR, Sibel; Sari, Nebahat

    2014-01-01

    This study was conducted to investigate the effect of vesicular-arbuscular (VA) mycorrhizae on plant growth of cucumber. Yayla F 1 seeds were sown in sterile and non-sterile growing medium (organic manure:soil:mix of sand; v:v:v 1:1:1). The mix inoculum of Glomus mosseaand Glomus fasciculatumspores (10 g/plant) was placed 5 cm below the cucumber seed before sowing. In order to investigate the effects of VA mycorrhizae on plant growth, plant height, diameter, number of nodes were measured ...

  4. Chitinase in roots of mycorrhizal Allium porrum: regulation and localization.

    Science.gov (United States)

    Spanu, P; Boller, T; Ludwig, A; Wiemken, A; Faccio, A; Bonfante-Fasolo, P

    1989-04-01

    Chitinase (EC 3.2.1.14) activity was measured in roots of Allium prorrum L. (leek) during development of a vesicular-arbuscular mycorrhizal symbiosis with Glomus versiforme (Karst.) Berch. During the early stages of infection, between 10 and 20 d after inoculation, the specific activity of chitinase was higher in mycorrhizal roots than in the uninfected controls. However, 60-90 d after inoculation, when the symbiosis was fully established, the mycorrhizal roots contained much less chitinase than control roots. Chitinase was purified from A. porrum roots. An antiserum against beanleaf chitinase was found to cross-react specifically with chitinase in the extracts from non-mycorrhizal and mycorrhizal A. porrum roots. This antiserum was used for the immunocytochemical localization of the enzyme with fluorescent and gold-labelled probes. Chitinase was localized in the vacuoles and in the extracellular spaces of non-mycorrhizal and mycorrhizal roots. There was no immunolabelling on the fungal cell walls in the intercellular or the intracellular phases. It is concluded that the chitin in the fungal walls is inaccessible to plant chitinase. This casts doubts on the possible involvement of this hydrolase in the development of the mycorrhizal fungus. However, fungal penetration does appear to cause a typical defense response in the first stages that is later depressed.

  5. APPARENT LACK OF VESICULAR-ARBUSCULAR MYCORRHIZA (VAM) IN SEAGRASSES ZOSTERA MARINA L. AND THALASSIA TESTUDIUM BANKS EX KONIG

    Science.gov (United States)

    We examined two populations of Zostera marina L. and one of Thalassia testudinum Banks ex Konig for presence of vesicular-arbuscular mycorrhiza (VAM). None of these plants showed any VAM colonization. In addition, we were unable to find any literature references on the presence o...

  6. Structure and function of mycorrhizal fungus communities of the Red Desert

    Energy Technology Data Exchange (ETDEWEB)

    McGraw, A.C.; Miller, R.M.

    1984-01-01

    A chronological study since 1977 in the Red Desert of Wyoming is enabling examination into the sequence of events coupling mycotrophy with revegetation following strip-mining activities. Observational data support the hypothesis that diversification in the plant community and structure is ensured with the establishment of the mycotrophic habit; thereby increasing resiliency of the community for recovery from perturbations. The objectives of this research were: (1) to identify the species of vesicular-arbuscular mycorrhizal fungi (MF) present and evaluate primary edaphic factors affecting the population dynamics of the MF; (2) to isolate native species of MF; and (3) to develop a model system for characterizing stresses such as extremes in moisture and temperature on the coupling and function (particularly the cost-benefit of mycotrophy to the host) of mycorrhizal symbionts. 2 tables.

  7. Vesicular-Arbuscular Mycorrhiza and Growth in Barley - Effects of Irradiation and Heating of Soil

    DEFF Research Database (Denmark)

    Jakobsen, Iver; Andersen, A. J.

    1982-01-01

    propagules. Mycorrhiza developed more slowly after inoculation in irradiated soils than in untreated soils. This could have been due to the small amounts of inoculum used, but the high concentrations of nutrients released by irradiation of the soil were probably of greater significance particularly......The influence of soil irradiation (0.25–4.0 Mrad) and soil heating on mycorrhizal survival, establishment and development after reinoculation, and on plant growth, was investigated. The lowest radiation dose applied, completely eliminated the infectivity of a soil with a high number of mycorrhizal...

  8. Influence of Al and the heavy metals Fe, Mn, Zn, Cu, Pb, and Cd on development and efficacy of vesicular-arbuscular mycorrhiza in tropical and subtropical plants. Einfluss von Al und den Schwermetallen Fe, Mn, Zn, Cu, Pb und Cd auf die Effizienz der VA-Mykorrhiza bei tropischen und subtropischen Pflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Fabig, B.

    1982-07-08

    In greenhouse experiments the influence of Al and the heavy metals Fe, Mn, Zn, Cu, Pb, and Cd on the efficacy of VA-mycorrhizal fungi was tested with special regard to several soil pH levels and soil water regimes in different combinations. The most important results were: The inoculation led to a significantly better growth of all test plants in the presence of Al, Fe, Mn, Zn, Cu, Pb, and Cd up to a specific amount of the soil-applied element; beyond this specific limit the efficacy of the mycorrhiza was more or less inhibited depending on the element. In correlation with the growth, the nearly always better P uptake of the inoculated plants was impaired only by the highest toxic amounts of the elements. In comparison with the uninoculated plants, all the inoculated plants showed higher P and Pb concentrations. The mycorrhizal plants generally had significantly higher concentrations of the elements Al, Mn, Zn, Cu, and Cd in the roots than the uninoculated plants. Generally even toxic levels of Fe in the soil did not lead to higher Fe concentrations in the plants. Even the highest amounts of Al, Fe, Mn, Zn, and Cu did not cause microscopically visible injuries to the development of the mycorrhiza and did not impede the infection. Only the toxic levels of Pb led to a decrease of the infection rate of about 50%. Pb and Cd were the reason for morphological changes of the different developmental phases of the fungus. High amounts of Pb induced an increased formation of vesicles. The highest amounts of Cd were accompanied by the crowded occurrence of arbuscules.

  9. Interspecific plant association effects on vesicular-arbuscular mycorrhiza occurrence in Atriplex confertifolia

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.M.; Moorman, T.B.; Schmidt, S.K.

    1983-01-01

    Earlier studies with the shrub Atriplex confertifolia (Chenopodiaceae) suggested that the occurrence of mycotrophy was related to the community from which root samples were obtained; plants in disturbed areas were non-mycotrophic, while those growing in native areas possessed infection. Upon closer examination when neighbouring plants were studied, the level of mycorrhizal infection of Atriplex confertifolia was found to be related to its interspecific plant associations. When Atriplex confertifolia occurred solitarily, or in the presence of non-mycorrhizal A. gardneri, it was non-mycotrophic. However, when occurring near grasses or Artemisia spinescens, it possessed mycorrhiza infection. What appeared to be a community effect for the occurrence of mycorrhiza is nothing more than an association effect in which level of infection is related to the degree of mycorrhizal host plant cover. In disturbed communities little chance occurs for encountering a neighbouring mycorrhizal plant, while native plant communities are composed primarily of mycorrhizal counterparts. 22 references, 1 figure, 3 tables.

  10. Hyphal N transport by a vesicular-arbuscular mycorrhizal fungus associated with cucumber grown at three nitrogen levels

    DEFF Research Database (Denmark)

    Johansen, A.; Jakobsen, I.; Jensen, E.S.

    1994-01-01

    Cucumis sativus L. cv. Aminex (F1 hybrid) was grown alone or in symbiosis with Glomus intraradices Schenck and Smith in containers with two hyphal compartments (HC(A) and HC(B)) on either side of a root compartment (RC) separated by fine nylon mesh. Plants received a total of either 100, 200 or 400...

  11. Hyphal transport by a vesicular-arbuscular mycorrhizal fungus of N applied to the soil as ammonium or nitrate

    DEFF Research Database (Denmark)

    Johansen, A.; Jakobsen, I.; Jensen, E.S.

    1993-01-01

    with a hyphal compartment separated from the root compartment by a fine nylon mesh. Mineral N was then applied to the hyphal compartment as (NH4+)-N-15 or (NO3-)-N-15 at 5 cm distance from the root compartment. Soil samples were taken from the hyphal compartment at 1, 3 and 5 cm distance from the root...

  12. The Role of Teak Leaves (Tectona grandis), Rhizobium, and Vesicular-Arbuscular Mycorrhizae on Improving Soil Structure and Soil Nutrition

    Science.gov (United States)

    Yuliani; Rahayu, Y. S.

    2018-01-01

    Calcium is the largest mineral in calcareous soils. High levels of calcium carbonate lead to phosphate deposition. Nutrient deficiencies in calcareous soil (mainly Phosphate and Nitrogen) resulted only certain crops with a wide range of tolerances that can grow. Meanwhile, dynamics nutrient in calcareous soils also depend on the topography and decomposition of the litter in the growing vegetation. The purpose of this study was to describe the pattern of nutrient enhancement and soil-texture structures on calcareous soils after littering the teak leaves, Rhizobium and Vesicular Arbuscular Mycorrhiza. The research parameters were the concentration of N, P, K; C/N ratio, humid acid content, and soil structure, which measured at days 30, 60, and 85 of soil decomposition process. The results showed that at days 30, the texture and structure of the soil tend to be stable (porosity 31.2, DMR 1.93, moisture content 0.36, sandy clay) while at days 85 has been very stable (porosity 49.8; Water content 0.28, sandy clay). While C and N organic, N and K concentration at days 30 showed low value (C organic 1.03, N 0.12, K 0.49, C / N ratio 9). This condition is almost unchanged at days 85. While the P value shows very high value (60.53) at days 30 although after 60 days the P content showed a decrease.

  13. Effect of endomycorrhizae on interactions between mycorrhizal and nonmycorrhizal plants. [Glomus monosporum/mosseae; Atriplex canescens; Sitanion hystrix

    Energy Technology Data Exchange (ETDEWEB)

    Franson, R.; Miller, R.M.

    1984-01-01

    An investigation on how infection with vesicular-arbuscular mycorrhizal fungi (VAM) changes interactions between plants was initiated. Specifically addressed were how does the presence or absence of VAM affect: (1) a species that typically shows little or no infection; and (2) a species that typically possesses moderate levels of infection. Results show: roots for inoculated species were higher than uninoculated treatments; the above ground dry weight gain were significantly higher with inoculation. The growth response of both species suggests a fungus-to-plant interaction even though infection, as measured by arbuscules a vesicles, was not always present. 2 figures. (MF)

  14. Does ozone exposure alter growth and carbon allocation of mycorrhizal plants

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, L.C.; Gamon, J.A. (California State Univ., Los Angeles, CA (United States)); Andersen, C.P. (Environmental Protection Agency, Corvallis, OR (United States))

    1994-06-01

    Ozone is known to adversely affect plant growth. However, it is less clear how ozone affects belowground processes. This study tests the hypothesis that ozone alters growth and carbon allocation of vesicular arbuscular mycorrhizal (VAM) plants. Two ecotypes of Elymus glaucus (blue wild rye) were exposed to mycorrhizal inoculation and episodic ozone exposures simulating atmospheric conditions in the Los Angeles Basin. Preliminary results show that effects of ozone on growth were subtle. In both ecotypes, growth of aboveground biomass was not affected by ozone while root growth was decreased. In most treatments, mycorrhizal inoculation decreased growth of leaves and stems, but had no significant effect on root growth. Three-way ANOVA tests indicated interactive effects between ecotype, mycorrhiza and ozone. Further experimental work is needed to reveal the biological processes governing these responses.

  15. Growth and development of symbiotic Arbuscular mycorrhizal fungi ...

    African Journals Online (AJOL)

    Herbicides are applied to control weeds in agricultural practices and could also be detrimental to the development of some microorganisms living in the soil ecosystem. This study was conducted to determine the growth and development of mycorrhizal fungi, Glomus mossea (Nicol. and Gerd.), in soils treated with herbicides ...

  16. BIOFERTILIZATION WITH RHIZOBACTERIA AND A CONSORTIUM OF ARBUSCULAR MYCORRHIZAL FUNGI IN CITRUS ROOTSTOCKS

    Directory of Open Access Journals (Sweden)

    Roberto Gregorio Chiquito-Contreras

    2012-11-01

    Full Text Available Biofertilization of plants with rhizobacteria and vesicular arbuscular mycorrhizae (mycorrhizal consortium, potentially promotes plant growth and health, and reduces the use of agrochemicals. The effect of individual and combined biofertilization with three strains of rhizobacteria and the mycorrhizal consortium (MTZ-1 was evaluated under nursery conditions on the growth of rootstocks of Citrus volkameriana and Rangpur lime grafted with Tahiti lime. Plants were inoculated individually and combined with the rhizobacteria strains FCA-8, FCA-56 and FCA-60 of Pseudomonas putida, and with MTZ-1; 50 % fertilization also was applied (18-46-00 N-P-K and compared with controls that received nursery management and 100 % fertilization. A split-plot experimental design with five replications per treatment was established. Individual and combined biofertilization with the three strains of bacteria and MTZ-1 positively promoted the growth of C. volkameriana, and Rangpur lime grafted with Tahiti lime, similar to the control with 100 % fertilization. The nutrient content of Tahiti lime leaves was similar to the control for both rootstocks. The presence of rhizobacterial and mycorrhizal populations in the combined biofertilization treatments demonstrated a positive synergism in the colonization of rootstock roots. Results demonstrate the potential of the three strains of P. putida and the MTZ-1 mycorrhizal consortium on the promotion of plant growth and assimilation of nutrients.

  17. Development of soil quality metrics using mycorrhizal fungi

    Energy Technology Data Exchange (ETDEWEB)

    Baar, J.

    2010-07-01

    Based on the Treaty on Biological Diversity of Rio de Janeiro in 1992 for maintaining and increasing biodiversity, several countries have started programmes monitoring soil quality and the above- and below ground biodiversity. Within the European Union, policy makers are working on legislation for soil protection and management. Therefore, indicators are needed to monitor the status of the soils and these indicators reflecting the soil quality, can be integrated in working standards or soil quality metrics. Soil micro-organisms, particularly arbuscular mycorrhizal fungi (AMF), are indicative of soil changes. These soil fungi live in symbiosis with the great majority of plants and are sensitive to changes in the physico-chemical conditions of the soil. The aim of this study was to investigate whether AMF are reliable and sensitive indicators for disturbances in the soils and can be used for the development of soil quality metrics. Also, it was studied whether soil quality metrics based on AMF meet requirements to applicability by users and policy makers. Ecological criterions were set for the development of soil quality metrics for different soils. Multiple root samples containing AMF from various locations in The Netherlands were analyzed. The results of the analyses were related to the defined criterions. This resulted in two soil quality metrics, one for sandy soils and a second one for clay soils, with six different categories ranging from very bad to very good. These soil quality metrics meet the majority of requirements for applicability and are potentially useful for the development of legislations for the protection of soil quality. (Author) 23 refs.

  18. Programming good relations - development of the arbuscular mycorrhizal symbiosis

    OpenAIRE

    Reinhardt, Didier

    2007-01-01

    The majority of plants live in symbiotic associations with fungi or bacteria that improve their nutrition. Critical steps in a symbiosis are mutual recognition and subsequently the establishment of an intimate association, which involves the penetration of plant tissues and, in many cases, the invasion of individual host cells by the microbial symbiont. Recent advances revealed that in the arbuscular mycorrhizal symbiosis with soil fungi of the order Glomeromycota, plant-derived signals attra...

  19. Development of phylogenetic markers for Sebacina (Sebacinaceae) mycorrhizal fungi associated with Australian orchids.

    Science.gov (United States)

    Ruibal, Monica P; Peakall, Rod; Foret, Sylvain; Linde, Celeste C

    2014-06-01

    To investigate fungal species identity and diversity in mycorrhizal fungi of order Sebacinales, we developed phylogenetic markers. These new markers will enable future studies investigating species delineation and phylogenetic relationships of the fungal symbionts and facilitate investigations into evolutionary interactions among Sebacina species and their orchid hosts. • We generated partial genome sequences for a Sebacina symbiont originating from Caladenia huegelii with 454 genome sequencing and from three symbionts from Eriochilus dilatatus and one from E. pulchellus using Illumina sequencing. Six nuclear and two mitochondrial loci showed high variability (10-31% parsimony informative sites) for Sebacinales mycorrhizal fungi across four genera of Australian orchids (Caladenia, Eriochilus, Elythranthera, and Glossodia). • We obtained highly informative DNA markers that will allow investigation of mycorrhizal diversity of Sebacinaceae fungi associated with terrestrial orchids in Australia and worldwide.

  20. Exogenous Polyamines Improve Mycorrhizal Development And Growth And Flowering Of Freesia hybrida

    Directory of Open Access Journals (Sweden)

    Rezvanypour Shirin

    2015-12-01

    Full Text Available An experiment was conducted in order to investigate the effects of exogenous polyamines (PAs on the development of mycorrhizae in roots, nutrient uptake and vegetative and reproductive growth of Freesia hybrida ‘Golden Wave’. Corms of freesia were inoculated with Rhizophagus intraradices at sowing time and treated once a week by one of three PAs, putrescine (Put, spermidine or spermine, in concentrations of 0.05 and 0.1 mM each as foliar application or soil drench. Application of PAs, especially as soil drench, increased mycorrhizal colonization as well as the growth and development of inoculated plants. Among the three PAs, Put in 0.1 mM concentration was the most effective in increasing colonization, enhancing floral stem length and diameter, floral spike length, floret number on main and lateral spikes and increasing corm and cormlet weight, corm diameter and cormlet number. Sole application of arbuscular mycorrhizal fungi had no significant effect on the flowering time but soil drench with 0.1 mM Put accelerated flowering by about 17 days. Application of PAs elevated leaves N, P, K, Mg, Fe and Zn and corms’ P, K, Ca, Fe and Zn concentration of inoculated plants. Our results suggest that soil drench application of PAs, especially Put, positively influenced mycorrhizal inoculation and nutrient uptake, which leads to improving growth, flower and corm production and quality of mycorrhizal plants of freesia.

  1. Vesicular-arbuscular mycorrhiza in guayule

    Energy Technology Data Exchange (ETDEWEB)

    Bloss, H.E.

    1980-01-01

    There is renewed interest in the cultivation of guayule (Parthenium argentatum A. Gray) as a domestic source of natural rubber. Guayule roots from Texas were observed for the presence of mycorrihizae. A symbiont identified as Glomus fasciculatus has been isolated. (ACR)

  2. Carbon cost of the fungal symbiont relative to net leaf P accumulation in a split-root VA mycorrhizal symbiosis. [Poncirus trifoliata L. Raf. x Citrus sinensis L. Osbeck; Glomus intraradices Schenk and Smith

    Energy Technology Data Exchange (ETDEWEB)

    Douds, D.D. Jr.; Johnson, C.R.; Koch, K.E. (Univ. of Florida, Gainesville (USA))

    1988-02-01

    Translocation of {sup 14}C-photosynthates to mycorrhizal (++), half mycorrhizal (0+), and nonmycorrhizal (00) split-root systems was compared to P accumulation in leaves of the host plant. Carrizo citrange seedlings (Poncirus trifoliata (L.) Raf. {times} Citrus sinensis (L.) Osbeck) were inoculated with the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck and Smith. Plants were exposed to {sup 14}CO{sub 2} for 10 minutes and ambient air for 2 hours. Three to 4% of recently labeled photosynthate was allocated to metabolism of the mycorrhiza in each inoculated root half independent of shoot P concentration, growth response, and whether one or both root halves were colonized. Nonmycorrhizal roots respired more of the label translocated to them than did mycorrhizal roots. Label recovered in the potting medium due to exudation or transport into extraradical hyphae was 5 to 6 times greater for (++) versus (00) plants. In low nutrient media, roots of (0+) and (++) plants transported more P to leaves per root weight than roots of (00) plants. However, when C translocated to roots utilized for respiration, exudation, etc., as well as growth is considered, (00) plant roots were at least as efficient at P uptake (benefit) per C utilized (cost) as (0+) and (++) plants. Root systems of (++) plants did not supply more P to leaves than (0+) plants in higher nutrient media, yet they still allocated twice the {sup 14}C-photosynthate to the mycorrhiza as did (0+) root systems.

  3. Influence of mycorrhizal fungi on the growth and development of sandy everlasting Helichrysum arenarium (L. Moench.

    Directory of Open Access Journals (Sweden)

    Anna K. Sawilska

    2012-12-01

    Full Text Available The significance of root colonization by mycorrhizal fungi for the growth and development of Helichrysum arenarium was investigated in two independent experiments. In the first experiment the association of root colonization level with the pluviothermal conditions within the growing season and the age of a natural plant population was analyzed. In the second one, under controlled conditions, the influence of artificial inoculation with the arbuscular fungus Glomus intraradices on the features of plants raised from achenes was studied. It was shown that hydrothermal conditions during blooming period had a greater influence on reproduction processes of sandy everlasting than both the population age (the secondary succession progress and the level of root colonization by mycorrhizal fungi. High amount of precipitation at plant generative development phase positively influences the potential and actual fertility of ramets. The presence of arbuscular fungus in the soil favors the growth and development of sandy everlasting specimens at their early growing stages: they have a better-developed root system and a greater photosynthetic area.

  4. Development of cassava plants and its mycorrhizal association in soil supplemented with sugarcane agroindustrial residue

    Directory of Open Access Journals (Sweden)

    Jorge Messias Leal Nascimento

    2014-02-01

    Full Text Available Application of organic agroindustrial residues on agriculture can be one way to improve the development and chemical composition of plants, reducing the cost with chemical fertilizers and impacts generated by the excessive use of them. Sugarcane agroindustrial residue has been generated in high quantity in Brazilian semiarid region and can be applied to cassava crop to improve its growth. The aim of this work was to evaluate the effect of application of sugarcane agroindustrial residue on the vegetative development, chemical composition and mycorrhizal association of cassava plants (Manihot esculenta var. Engana ladrão. It was performed an experiment in greenhouse with completely randomized design with four treatments of addition of sugarcane agroindustrial residue (0, 5, 10 and 15% with nine replicates. The addition of sugarcane agroindustrial residue increased fresh dry root biomass, leaf area, crude protein and mineral matter, without reducing the mycorrhizal colonization and glomerospores number. This type of residue can be one alternative to improve the nutritional value of these fodder.

  5. EFFECT OF MYCORRHIZAL INOCULANTS IN THE DEVELOPMENT OF MEXICAN LANDRACE AVOCADO ROOTSTOCKS

    Directory of Open Access Journals (Sweden)

    Edgar Castro Alvarado

    2013-12-01

    Full Text Available The aim of this work was to assess the effect of two arbuscular mycorrhizal fungi (AMF inoculants in the development of avocado rootstocks. Seeds of Mexican landrace avocado (Persea americana Mill. var. drymifolia were used, with two commercial inoculants: T1 containing Glomus fasciculatum, G. constrictum, G. tortuosum, G. geosporum,and Acaulospora scrobiculata, and T2, containing G. mosseae and G. cubense.  The plants inoculated with AMF showed more rapid growth than the no inoculant control as measured by plant height (50% and 54%, stem diameter (35% and 36%, leaf number (48% and 37% and length (31% and 40%, and root fresh weight (85% and 59%; however, no significant differences were observed between T1 and T2. The chlorophyll concentration in the leaves from T1 was 16.4% and T2 was 19% higher than the control suggesting a higher photosynthetic capacity in T1 and T2. Finally the shoot/root ratio, as indicator of the potential development of plantations, was 79% and 50% higher in mycorrhizal plants than in the control. In conclusion both T1 and T2 inoculants improved growth rate and vigor of avocado nursery rootstocks producing higher quality plants.

  6. Auxin Perception Is Required for Arbuscule Development in Arbuscular Mycorrhizal Symbiosis1[W

    Science.gov (United States)

    Etemadi, Mohammad; Gutjahr, Caroline; Couzigou, Jean-Malo; Zouine, Mohamed; Lauressergues, Dominique; Timmers, Antonius; Audran, Corinne; Bouzayen, Mondher; Bécard, Guillaume; Combier, Jean-Philippe

    2014-01-01

    Most land plant species live in symbiosis with arbuscular mycorrhizal fungi. These fungi differentiate essential functional structures called arbuscules in root cortical cells from which mineral nutrients are released to the plant. We investigated the role of microRNA393 (miR393), an miRNA that targets several auxin receptors, in arbuscular mycorrhizal root colonization. Expression of the precursors of the miR393 was down-regulated during mycorrhization in three different plant species: Solanum lycopersicum, Medicago truncatula, and Oryza sativa. Treatment of S. lycopersicum, M. truncatula, and O. sativa roots with concentrations of synthetic auxin analogs that did not affect root development stimulated mycorrhization, particularly arbuscule formation. DR5-GUS, a reporter for auxin response, was preferentially expressed in root cells containing arbuscules. Finally, overexpression of miR393 in root tissues resulted in down-regulation of auxin receptor genes (transport inhibitor response1 and auxin-related F box) and underdeveloped arbuscules in all three plant species. These results support the conclusion that miR393 is a negative regulator of arbuscule formation by hampering auxin perception in arbuscule-containing cells. PMID:25096975

  7. Two Medicago truncatula Half-ABC Transporters Are Essential for Arbuscule Development in Arbuscular Mycorrhizal Symbiosis

    National Research Council Canada - National Science Library

    Quan Zhang; Laura A. Blaylock; Maria J. Harrison

    2010-01-01

    In the symbiotic association of plants and arbuscular mycorrhizal (AM) fungi, the fungal symbiont resides in the root cortical cells where it delivers mineral nutrients to its plant host through branched hyphae called arbuscules...

  8. The Lotus japonicus MAMI gene links root development, arbuscular mycorrhizal symbiosis and phosphate availability.

    Science.gov (United States)

    Volpe, Veronica; Dell'Aglio, Elisa; Bonfante, Paola

    2013-03-01

    The arbuscular mycorrhizal-induced LjMAMI gene is phylogenetically related to GARP transcription factors involved in Pi-starvation responses such as AtPHR1. The gene is strongly upregulated in arbusculated cells from mycorrhizal plants and in root meristems, irrespectively of the fungal presence. A further expression analysis revealed a similar expression pattern for LjPT4, considered a marker gene for mycorrhizal functionality. Here we show that the LjPT4 promoter contains two conserved cis-acting elements typically found in Pi-starvation induced Pi transporters. One of these is strongly related to the binding site of AtPHR1, suggesting a direct regulation of LjPT4 by LjMAMI. The expression of both genes in non-mycorrhizal tissues leads to the hypothesis that these symbiosis-inducible genes are also involved in Pi starvation responses in root meristems in an AM-independent manner.

  9. United States Air Force Summer Faculty Research Program for 1990. Program Management Report

    Science.gov (United States)

    1991-06-05

    Laboratory 144 An Assay to Determine the Phytotoxic Effects Dr. David Buckalew of Jet Fuel: Effects on Vesicular- Arbuscular Mycorrhizae 114 Volume IV...Fuel: Effects on Vesicular- Arbuscular Mycorrhizae by David W. Buckalew ABSTRACT A new protocol is presented for using plants as analytical tools to...measures of total root length and percent vesicular- arbuscular mycorrhizal colonization are recorded within a common test grass. A brief discussion of

  10. Characterization of seed germination and protocorm development of Cyrtopodium glutiniferum (Orchidaceae promoted by mycorrhizal fungi Epulorhiza spp.

    Directory of Open Access Journals (Sweden)

    Marlon Corrêa Pereira

    2015-12-01

    Full Text Available Cyrtopodium glutiniferum is an endemic orchid of Brazil with potential medicinal and ornamental applications. As mycorrhizal fungi are essential for the initiation of the orchid life cycle, the aim of this study was to determine the strains of mycorrhizal fungi suitable for seed germination and protocorm development of C. glutiniferum and to characterize the symbiotic development of protocorms. Seeds of C. glutiniferum were inoculated with nine mycorrhizal fungi, Epulorhiza spp., Ceratorhiza spp., Rhizoctonia sp., originally isolated from Brazilian neotropical orchids. Only Epulorhiza isolates promoted seed germination and protocorm development. Three Epulorhiza isolates (M1, M6 = E. epiphytica, M20 = Epulorhiza sp. promoted protocorm development until leaf production at 63 days. The protocorms are comprised of parenchyma cells delimited by a unistratified epidermis; the parenchyma cells of the upper part of the protocorms are smaller than those located more towards the base. Intact and digested pelotons were observed inside of protocorms implying that the seedlings were capable of mycotrophy. Additionally, the development of a bud primordium only occurred after colonization by fungus. This study suggests that C. glutiniferum has a preference for strains of Epulorhiza and that fungus digestion is essential to protocorm development.

  11. Interactions between ethylene, gibberellins, and brassinosteroids in the development of rhizobial and mycorrhizal symbioses of pea.

    Science.gov (United States)

    Foo, Eloise; McAdam, Erin L; Weller, James L; Reid, James B

    2016-04-01

    The regulation of arbuscular mycorrhizal development and nodulation involves complex interactions between the plant and its microbial symbionts. In this study, we use the recently identified ethylene-insensitive ein2 mutant in pea (Pisum sativum L.) to explore the role of ethylene in the development of these symbioses. We show that ethylene acts as a strong negative regulator of nodulation, confirming reports in other legumes. Minor changes in gibberellin1 and indole-3-acetic acid levels in ein2 roots appear insufficient to explain the differences in nodulation. Double mutants produced by crosses between ein2 and the severely gibberellin-deficient na and brassinosteroid-deficient lk mutants showed increased nodule numbers and reduced nodule spacing compared with the na and lk single mutants, but nodule numbers and spacing were typical of ein2 plants, suggesting that the reduced number of nodules innaandlkplants is largely due to the elevated ethylene levels previously reported in these mutants. We show that ethylene can also negatively regulate mycorrhizae development when ethylene levels are elevated above basal levels, consistent with a role for ethylene in reducing symbiotic development under stressful conditions. In contrast to the hormone interactions in nodulation, ein2 does not override the effect of lk or na on the development of arbuscular mycorrhizae, suggesting that brassinosteroids and gibberellins influence this process largely independently of ethylene. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  12. Bacterial effects on arbuscular mycorrhizal fungi and mycorrhiza development as influenced by the bacteria, fungi, and host plant.

    Science.gov (United States)

    Pivato, Barbara; Offre, Pierre; Marchelli, Sara; Barbonaglia, Bruno; Mougel, Christophe; Lemanceau, Philippe; Berta, Graziella

    2009-02-01

    Bacterial strains from mycorrhizal roots (three belonging to Comamonadaceae and one to Oxalobacteraceae) and from non-mycorrhizal roots (two belonging to Comamonadaceae) of Medicago truncatula and two reference strains (Collimonas fungivorans Ter331 and Pseudomonas fluorescens C7R12) were tested for their effect on the in vitro saprophytic growth of Glomus mosseae BEG12 and on its colonization of M. truncatula roots. Only the Oxalobacteraceae strain, isolated from barrel medic mycorrhizal roots, and the reference strain P. fluorescens C7R12 promoted both the saprophytic growth and root colonization of G. mosseae BEG12, indicating that they acted as mycorrhiza helper bacteria. Greatest effects were achieved by P. fluorescens C7R12 and its influence on the saprophytic growth of G. mosseae was compared to that on Gigaspora rosea BEG9 to determine if the bacterial stimulation was fungal specific. This fungal specificity, together with plant specificity, was finally evaluated by comparing bacterial effects on arbuscular mycorrhizal symbiosis when each of the fungal species was inoculated to two different plant species (M. truncatula and Lycopersicon esculentum). The results obtained showed that promotion of saprophytic growth by P. fluorescens C7R12 was expressed in vitro towards G. mosseae but not towards G. rosea. Bacterial promotion of mycorhization was also expressed towards G. mosseae, but not G. rosea, in roots of M. truncatula and L. esculentum. Taken together, results indicated that enhancement of arbuscular mycorrhiza development was only induced by a limited number of bacteria, promotion by the most efficient bacterial strain being fungal and not plant specific.

  13. Can we develop general predictive models of mycorrhizal fungal community-environment relationships?

    Science.gov (United States)

    Erik A. Lilleskov; Jeri L. Parrent

    2007-01-01

    Our understanding of the controls on mycorrhizal fungal species distribution and community organization is in its early childhood - especially when compared with that of the more mature fields of plant and animal community ecology and biogeography - largely because of the historical difficulty of gathering species distribution information.

  14. Mycorrhizal phosphate uptake pathway in maize: Vital for growth and cob development on nutrient poor agricultural and greenhouse soils

    Directory of Open Access Journals (Sweden)

    Martin eWillmann

    2013-12-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF form a mutually beneficial symbiosis with plant roots providing predominantly phosphorus in the form of orthophosphate (Pi in exchange for plant carbohydrates on low P soils. The goal of this work was to generate molecular-genetic evidence in support of a major impact of the mycorrhizal Pi uptake (MPU pathway on the productivity of the major crop plant maize under field and controlled conditions. Here we show, that a loss-of-function mutation in the mycorrhiza-specific Pi transporter gene Pht1;6 correlates with a dramatic reduction of above-ground biomass and cob production in agro-ecosystems with low P soils. In parallel mutant pht1;6 plants exhibited an altered fingerprint of chemical elements in shoots dependent on soil P availability. In controlled environments mycorrhiza development was impaired in mutant plants when grown alone. The presence of neighbouring mycorrhizal nurse plants enhanced the reduced mycorrhiza formation in pht1;6 roots. Uptake of 33P-labelled orthophosphate via the MPU pathway was strongly impaired in colonized mutant plants. Moreover, repression of the MPU pathway resulted in a redirection of Pi to neighbouring plants. In line with previous results, our data highlight the relevance of the MPU pathway in Pi allocation within plant communities and in particular the role of Pht1;6 for the establishment of symbiotic Pi uptake and for maize productivity and nutritional value in low-input agricultural systems. In a first attempt to identify cellular pathways which are affected by Pht1;6 activity, gene expression profiling via RNA-Seq was performed and revealed a set of maize genes involved in cellular signalling which exhibited differential regulation in mycorrhizal pht1;6 and control plants. The RNA data provided support for the hypothesis that fungal supply of Pi and/or Pi transport across Pht1;6 affects cell wall biosynthesis and hormone metabolism in colonized root cells.

  15. 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.

  16. Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation: a biotechnological perspective.

    Science.gov (United States)

    Kumar, Ashwani; Dames, Joanna F; Gupta, Aditi; Sharma, Satyawati; Gilbert, Jack A; Ahmad, Parvaiz

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, "omics" technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.

  17. Does mycorrhizal inoculation benefit plant survival, plant development and small-scale soil fixation? Results from a perennial eco-engineering field experiment in the Swiss Alps.

    Science.gov (United States)

    Bast, Alexander; Grimm, Maria; Graf, Frank; Baumhauer, Roland; Gärtner, Holger

    2015-04-01

    In mountain environments superficial slope failures on coarse grained, vegetation-free slopes are common processes and entail a certain risk for humans and socio-economic structures. Eco-engineering measures can be applied to mitigate slope instabilities. In this regard, limited plant survival and growth can be supported by mycorrhizal inoculation, which was successfully tested in laboratory studies. However, related studies on a field scale are lacking. Furthermore, mycorrhizae are known to enhance soil aggregation, which is linked to soil physics such as shear strength, and hence it is a useful indicator for near-surface soil/slope stability. The overall objective of our contribution was to test whether mycorrhizal inoculation can be used to promote eco-engineering measures in steep alpine environments based on a five-year field experiment. We hypothesized that mycorrhizal inoculation (i) enhances soil aggregation, (ii) stimulate plant survival and fine root development, (iii) effects plant performance, (iv) the stimulated root development in turn influences aggregate stability, and (v) that climatic variations play a major role in fine-root development. We established mycorrhizal and non-mycorrhizal treated eco-engineered research plots (hedge layers mainly consisting of Alnus spp. and Salix spp.) on a field experimental scale. The experimental site is in the eastern Swiss Alps at an erosion-prone slope where many environmental conditions can be seen as homogeneous. Soil aggregation, fine root development and plant survival was quantified at the end of four growing seasons (2010, '11, '12, '14). Additionally, growth properties of Alnus spp. and Salix spp. were measured and their biomass estimated. Meteorological conditions, soil temperature and soil water content were recorded. (i) The introduced eco-engineering measures enhanced aggregate stability significantly. In contrast to published greenhouse and laboratory studies, mycorrhizal inoculation delayed soil

  18. 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

  19. Influence of vesicular arbuscular mycorrhiza (VAM) and phosphate ...

    African Journals Online (AJOL)

    User

    2013-09-18

    Sep 18, 2013 ... Organic wastes and biofertilizers are alternate sour- ... consequence of regular application of chemical fertilizers. However, a large proportion of soluble inorganic phos- phate added to soil is rapidly fixed as insoluble forms.

  20. Effect of solarization and vesicular arbuscular mychorrizal on weed ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... To determine VAM before testing in laboratory, VAM dutied like a bridge from donor lettuce to receiver wild mustard (Sinapsis arvensis L.) as observed in the experiment because mustrad has no symbiosis life with this fungus. Also the laboratory findings supported this; the number of spores, number of VAM.

  1. Effect of solarization and vesicular arbuscular mychorrizal on weed ...

    African Journals Online (AJOL)

    mustard (Sinapsis arvensis L.) as observed in the experiment because mustrad has no symbiosis life with this fungus. Also the laboratory findings supported this; the number of spores, number of VAM infected and infection rate were higher both in main parcel of solarized and in the subplot parcel planted with VAM ...

  2. Chemical identification and functional analysis of apocarotenoids involved in the development of arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Akiyama, Kohki

    2007-06-01

    Arbuscular mycorrhizae formed between more than 80% of land plants and arbuscular mycorrhizal (AM) fungi represent the most widespread symbiosis on the earth. AM fungi facilitate the uptake of soil nutrients, especially phosphate, by plants, and in return obtain carbohydrates from hosts. Apocarotenoids, oxidative cleavage products of carotenoids, have been found to play a critical role in the establishment of AM symbiosis. Strigolactones previously isolated as seed-germination stimulants for root parasitic weeds act as a chemical signal for AM fungi during presymbiotic stages. Stimulation of carotenoid metabolism, leading to massive accumulation of mycorradicin and cyclohexenone derivatives, occurs during root colonization by AM fungi. This review highlights research into the chemical identification of arbuscular mycorrhiza-related apocarotenoids and their role in the regulation and establishment of AM symbiosis conducted in the past 10 years.

  3. Influence of mycorrhizal developmental stages and plant age on rhizosphere mycoflora of Pinus kesiya (Royle

    Directory of Open Access Journals (Sweden)

    G. D. Sharma

    2014-08-01

    Full Text Available Quantitatively the population was recorded to be high around thc mycorrhizal roots. Some fungi were specific to different stages of mycorrhizal development. Rhizopus nigricans and Cunninghamella elegans were recorded at 5% mycorrhizal association stage. Fusarium sp. was found at 20% mycorrhizal association, while Mucor spp. were obtained at 60% stage. Verticillium sp. had the highest frequency of occurrence in the beginning of mycorrhizal association but later on Penicilium spp. were found to be the most common. Sugar content of mycorrhizal and nonmycorrhizal roots were determined to assess their effect on the mycorrhizospheric micropopulation. The mannitol and trehalose were present only in mycorrhizal roots.

  4. Fungos micorrízicos vesículo-arbusculares em rizosferas de plantas em dunas do Parque Estadual da Ilha do Cardoso, São Paulo, Brasil: (1 Taxonomia Vesicular-arbuscular mycorrhizal fungi from rhizospheres of dunes plants of Parque Estadual da Ilha do Cardoso, São Paulo State, Brazil (1: taxonomy

    Directory of Open Access Journals (Sweden)

    S. F. B Trufem

    1989-01-01

    Full Text Available De março/1988 a março/1989, mensalmente, foram coletadas o total de 450 amostras de solo de rizosferas de plantas de dunas do Parque Estadual da Ilha do Cardoso, Estado de Sáo Paulo, com a finalidade de se verificar a ocorrência de fungos micorrízicos vesículo-arbusculares (MVA. As plantas mais constantemente investigadas foram: Baccharis trimera DC. (Compositae, Blutaparon portulacoides (St. Hü. Mears (Amaranthaceae, Dalbergia hecastaphylla (L. Taub. (Legurninosae, Hydrocotyle bonariensis Lam. (Umbelliferae,Ipomoeapes-caprae (L.Sweet(Convolvulaceae, Polygaid cyparisseas St. Hül & Moq. (Polygalaceae, além de gramíneas, ciperáceas e outras, que foram coletadas mais esporadicamente. O solo foi tratado pela técnica de decantação e peneiramento em via úmida. Foram verificados 14 taxons de fungos MVA: Acaulospora scrobiculata Trappe, Acaulospora tuberculata Janos & Trappe, Cigaspora gigantea (Nicol. & Gerd. Gerd. & Trappe, Glomus fasciculatum (Thaxter Gerd. & Trappe emend. Walker & Koske, Glomus globiferum Koske & Walker, Glomus monosporum Gerd. & Trappe, Sclerocystis sinuosa Gerd. & Bakshi, Scutellospora calospora (Nicol & Gerd Walker & Sanders, Scutellospora coralloidea (Trappe, Gerd. & Ho (Walker & Sanders, Scutellospora gilmorei (Trappe & Gerd. Walker & Sanders, Scutellospora gregaria (Schenck & Nicol. Walker & Sanders, Scutellospora pérsica (Koske & Walker Walker & Sanders, Scutellospora verrucosa Koske & Walker Walker & Sanders e Scutellospora sp. São apresentadas descrições taxonómicas, comentarios e murônimos dos taxons verificados.Monthly, from March/1988 to March/1989 were collected the total of 450 soil samples from rhizospheres of plants from dunes of Parque Estadual da Ilha do Cardoso, São Paulo State, Brazil, to report the occurrence of VANÍ fungus. The investigated plants were: Baccharis trímera DC. (Compositae, Blutaparon portulacoides (St. Hil. Mears (Amaranthaceae, Dalbergia hecastaphylla (L. Taub. (Legumiosae, Hydrocotyle bonariensis Lam. (Umbelliferae, Ipomoea pes-caprae (L. Sweet (Convolvulaceae, Polygala cyparisseas St. Hill & Moq. (Polygalaceae; Gramineae, Cyperaceae and other plants were occasionaly collected. The soil was prepared according the wet sieving and decanting technique. It was observed the following 14 taxa of VA M fungüs: Acaulospora scrobiculata Trappe, Acaulospora tuberculata Janos & Trappe, Gigaspora gigantea (Nicol. & Gerd Gerd & Trappe, Glomus fasciculatum (Thaxter Gerd. & Trappe emend. Walker & Koske, Glomus globiferum Koske & Walker, Glomus monosporum Gerd. & Trappe, Sclerocystís sinuosa Gerd. & Bakshi, Scutellospora calospora (Nicol. & Gerd. Walker & Sanders, Scutellospora collaroidea (Trappe, Gerd. & Ho Walker & Sanders, Scutellospora gilmorei (Trappe & Gerd. Walker & Sanders, Scutellospora gregaria (Schénck & Nicol. Walker & Sanders, Scutellospora pérsica (Koske & Walker Walker & Sanders, Scutellospora verrucosa (Koske & Walker Walker & Sanders and Scutellospora sp. Are presented taxonomical, coments and muronyms of the studied taxa.

  5. 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.

  6. Application of the EDYS Model to Evaluate Control Methods for Invasive Plants at Yakima Training Center, Washington

    Science.gov (United States)

    2004-12-01

    Anderson. 1987. Effects of soil moisture and soil sterilization on vesicular- arbuscular mycorrhizal colonization and growth of little bluestem...potassium, and in the density of mycorrhiza , in biennial and matrix-forming perennial species of closed chalkland turf. Journal of Ecology 70:571-593...nitrogen between pasture plants infected with vesicular- arbuscular mycorrhizal fungi. New Phytologist 108:417-423. Heil, G.W. and W.H. Diemont. 1983

  7. Two Medicago truncatula Half-ABC Transporters Are Essential for Arbuscule Development in Arbuscular Mycorrhizal Symbiosis[W

    Science.gov (United States)

    Zhang, Quan; Blaylock, Laura A.; Harrison, Maria J.

    2010-01-01

    In the symbiotic association of plants and arbuscular mycorrhizal (AM) fungi, the fungal symbiont resides in the root cortical cells where it delivers mineral nutrients to its plant host through branched hyphae called arbuscules. Here, we report a Medicago truncatula mutant, stunted arbuscule (str), in which arbuscule development is impaired and AM symbiosis fails. In contrast with legume symbiosis mutants reported previously, str shows a wild-type nodulation phenotype. STR was identified by positional cloning and encodes a half-size ATP binding cassette (ABC) transporter of a subfamily (ABCG) whose roles in plants are largely unknown. STR is a representative of a novel clade in the ABCG subfamily, and its orthologs are highly conserved throughout the vascular plants but absent from Arabidopsis thaliana. The STR clade is unusual in that it lacks the taxon-specific diversification that is typical of the ABCG gene family. This distinct phylogenetic profile enabled the identification of a second AM symbiosis-induced half-transporter, STR2. Silencing of STR2 by RNA interference results in a stunted arbuscule phenotype identical to that of str. STR and STR2 are coexpressed constitutively in the vascular tissue, and expression is induced in cortical cells containing arbuscules. STR heterodimerizes with STR2, and the resulting transporter is located in the peri-arbuscular membrane where its activity is required for arbuscule development and consequently a functional AM symbiosis. PMID:20453115

  8. Phylogeonomics and Ecogenomics of the Mycorrhizal Symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor V.; Kohler, Annegret; Martin, Francis

    2013-05-23

    Mycorrhizal fungi play critical roles in host plant health, soil community structure and chemistry, and carbon and nutrient cycling, all areas of intense interest to the US Dept. of Energy (DOE) Joint Genome Institute (JGI). To this end we are building on our earlier sequencing of the Laccaria bicolor genome by partnering with INRA-Nancy and the mycorrhizal research community in the MGI to sequence and analyze 2 dozen mycorrhizal genomes of numerous known mycorrhizal orders and several ecological types (ectomycorrhizal [ECM], ericoid, orchid, and arbuscular). JGI has developed and deployed high-throughput pipelines for genomic, transcriptomic, and re-sequencing, and platforms for assembly, annotation, and analysis. In the last 2 years we have sequenced 21 genomes of mycorrhizal fungi, and resequenced 6 additional strains of L. bicolor. Most of this data is publicly available on JGI MycoCosm?s Mycorrhizal Fungi Portal (http://jgi.doe.gov/Mycorrhizal_fungi/), which provides access to both the genome data and tools with which to analyze the data. These data allow us to address long-standing issues in mycorrhizal evolution and ecology. For example, a major observation of mycorrhizal evolution is that each of the major ecological types appears to have evolved independently in multiple fungal clades. Using an ecogenomic approach we provide preliminary evidence that 2 clades (Cantharellales and Sebacinales) of a single symbiotic ecotype (orchid) utilize some common regulatory (protein tyrosine kinase) and metabolic (lipase) paths, the latter of which may be the product of HGT. Using a phylogenomic approach we provide preliminary evidence that a particular ecotype (ericoid) may have evolved more than once within a major clade (Leotiomycetes).

  9. Cell wall remodeling in mycorrhizal symbiosis: a way towards biotrophism

    National Research Council Canada - National Science Library

    Balestrini, Raffaella; Bonfante, Paola

    2014-01-01

    .... All mycorrhizal interactions achieve full symbiotic functionality through the development of an extensive contact surface between the plant and fungal cells, where signals and nutrients are exchanged...

  10. Contribution of arbuscular mycorrhizal fungi to the development of maize (Zea mays L.) grown in three types of coal mine spoils.

    Science.gov (United States)

    Guo, Wei; Zhao, Renxin; Fu, Ruiying; Bi, Na; Wang, Lixin; Zhao, Wenjing; Guo, Jiangyuan; Zhang, Jun

    2014-03-01

    Coal mine spoils are usually unfavorable for plant growth and have different properties according to dumping years, weathering degree, and the occurrence of spontaneous combustion. The establishment of plant cover in mine spoils can be facilitated by arbuscular mycorrhizal fungi (AMF). A greenhouse pot experiment was conducted to evaluate the importance of AMF in plant adaptation to different mine spoils and the potential role of AMF for revegetation practices. We investigated the effects of Glomus aggregatum, Rhizophagus intraradices (syn. Glomus intraradices), and Funneliformis mosseae (syn. Glomus mosseae) on the growth, nutritional status, and metal uptake of maize (Zea mays L.) grown in recent discharged (S1), weathered (S2), and spontaneous combusted (S3) coal mine spoils. Symbiotic associations were successfully established between AMF and maize in three substrates. Mycorrhizal colonization effectively promoted plant growth by significantly increasing the uptake of nitrogen (N), phosphorus (P), and potassium (K), adjusting C:N:P stoichiometry and alleviating toxic effects of heavy metals. G. aggregatum, R. intraradices, and F. mosseae exhibited different mycorrhizal effects in response to mine spoil types. F. mosseae was the most effective in the development of maize in S1 and may be the most appropriate for revegetation of this substrate, while R. intraradices played the most beneficial role in S2 and S3. Our results suggest that inoculation with AMF can enhance plant adaptation to different types of coal mine spoils and play a positive role in the revegetation of coal mine spoil banks.

  11. Community assembly and coexistence in communities of arbuscular mycorrhizal fungi.

    Science.gov (United States)

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

    2016-10-01

    Arbuscular mycorrhizal fungi are asexual, obligately symbiotic fungi with unique morphology and genomic structure, which occupy a dual niche, that is, the soil and the host root. Consequently, the direct adoption of models for community assembly developed for other organism groups is not evident. In this paper we adapted modern coexistence and assembly theory to arbuscular mycorrhizal fungi. We review research on the elements of community assembly and coexistence of arbuscular mycorrhizal fungi, highlighting recent studies using molecular methods. By addressing several points from the individual to the community level where the application of modern community ecology terms runs into problems when arbuscular mycorrhizal fungi are concerned, we aim to account for these special circumstances from a mycocentric point of view. We suggest that hierarchical spatial structure of arbuscular mycorrhizal fungal communities should be explicitly taken into account in future studies. The conceptual framework we develop here for arbuscular mycorrhizal fungi is also adaptable for other host-associated microbial communities.

  12. EXO70I Is Required for Development of a Sub-domain of the Periarbuscular Membrane during Arbuscular Mycorrhizal Symbiosis.

    Science.gov (United States)

    Zhang, Xinchun; Pumplin, Nathan; Ivanov, Sergey; Harrison, Maria J

    2015-08-17

    In eukaryotic cells, polarized secretion mediated by exocytotic fusion of membrane vesicles with the plasma membrane is essential for spatially restricted expansion of the plasma membrane and for the delivery of molecules to specific locations at the membrane and/or cell surface. The EXOCYST complex is central to this process, and in yeast, regulation of the EXO70 subunit influences exocytosis and cargo specificity. In contrast to yeast and mammalian cells, plants have upwards of 23 EXO70 genes with largely unknown roles. During arbuscular mycorrhizal (AM) symbiosis, deposition of the plant periarbuscular membrane (PAM) around the fungal arbuscule creates an intracellular membrane interface between the symbionts. The PAM has two major membrane sub-domains, and symbiosis-specific transporter proteins are localized in the branch domain. Currently, the mechanisms and cellular machinery involved in biogenesis of the PAM are largely unknown. Here, we identify an EXO70I protein present exclusively in plants forming AM symbiosis. Medicago truncatula exo70i mutants are unable to support normal arbuscule development, and incorporation of two PAM-resident ABC transporters, STR and STR2, is limited. During arbuscule branching, EXO70I is located in spatially restricted zones adjacent to the PAM around the arbuscule hyphal tips where it interacts with Vapyrin, a plant-specific protein required for arbuscule development. We conclude that EXO70I provides a specific exocytotic capacity necessary for development of the main functional sub-domain of the PAM. Furthermore, in contrast to other eukaryotes, plant EXO70s have evolved distinct specificities and interaction partners to fulfill their specialized secretory requirements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. High phosphate reduces host ability to develop arbuscular mycorrhizal symbiosis without affecting root calcium spiking responses to the fungus

    Directory of Open Access Journals (Sweden)

    Coline eBalzergue

    2013-10-01

    Full Text Available The arbuscular mycorrhizal symbiosis associates soil fungi with the roots of the majority of plants species and represents a major source of soil phosphorus acquisition. Mycorrhizal interactions begin with an exchange of molecular signals between the two partners. A root signaling pathway is recruited, for which the perception of fungal signals triggers oscillations of intracellular calcium concentration. High phosphate availability is known to inhibit the establishment and/or persistence of this symbiosis, thereby favoring the direct, non symbiotic uptake of phosphorus by the root system. In this study, Medicago truncatula plants were used to investigate the effects of phosphate supply on the early stages of the interaction. When plants were supplied with high phosphate fungal attachment to the roots was drastically reduced. An experimental system was designed to individually study the effects of phosphate supply on the fungus, on the roots and on root exudates. These experiments revealed that the most important effects of high phosphate supply were on the roots themselves, which became unable to host mycorrhizal fungi even when these had been appropriately stimulated. The ability of the roots to perceive their fungal partner was then investigated by monitoring nuclear calcium spiking in response to fungal signals. This response did not appear to be affected by high phosphate supply. In conclusion, high levels of phosphate predominantly impact the plant host, but apparently not in its ability to perceive the fungal partner.

  14. Potential to breed for mycorrhizal association in durum wheat.

    Science.gov (United States)

    Ellouze, Walid; Hamel, Chantal; DePauw, R M; Knox, R E; Cuthbert, Richard D; Singh, Asheesh K

    2016-03-01

    The selection of genotypes under high soil fertility may alter the effectiveness of mycorrhizal symbioses naturally forming between crop plants and the mycorrhizal fungi residing in cultivated fields. We tested the hypothesis that the mycorrhizal symbiosis of 5 landraces functions better than the mycorrhizal symbiosis of 27 cultivars of durum wheat that were bred after the development of the fertilizer industry. We examined the development of mycorrhiza and the response of these genotypes to mycorrhiza formation after 4 weeks of growth under high and low soil fertility levels in the greenhouse. The durum wheat genotypes were seeded in an established extraradical hyphal network of Rhizophagus irregularis and in a control soil free of mycorrhizal fungi. The percentage of root length colonized by mycorrhizal fungi was lower in landraces (21%) than in cultivars (27%; P = 0.04) and in the most recent releases (29%; P = 0.02), which were selected under high soil fertility levels. Plant growth response to mycorrhiza varied from -36% to +19%. Overall, durum wheat plant breeding in Canada has increased the mycorrhizal development in wheat grown at a low soil fertility level. However, breeding had inconsistent effects on mycorrhizal development and has led to the production of cultivars with patterns of regulation ranging from unimproved to inefficient.

  15. Differential effects of fenpropimorph and fenhexamid, two sterol biosynthesis inhibitor fungicides, on arbuscular mycorrhizal development and sterol metabolism in carrot roots.

    Science.gov (United States)

    Campagnac, Estelle; Fontaine, Joël; Sahraoui, Anissa Lounès-Hadj; Laruelle, Frédéric; Durand, Roger; Grandmougin-Ferjani, Anne

    2008-12-01

    Sterols composition of transformed carrot roots incubated in presence of increasing concentrations of fenpropimorph (0.02; 0.2; 2mgl(-1)) and fenhexamid (0.02; 0.2; 2; 20mgl(-1)), colonized or not by Glomus intraradices was determined. In mycorrhizal roots treated with fenpropimorph, normal Delta(5)-sterols were replaced by unusual compounds such as 9beta,19-cyclopropylsterols (24-methylpollinastanol), Delta(8,14)-sterols (ergosta-8,14-dienol, stigmasta-8,14-dienol), Delta(8)-sterols (Delta(8) sitosterol) and Delta(7)-sterols (ergosta-7,22-dienol). After application of fenpropimorph, a drastic reduction of the mycorrhizal root growth, root colonization and extraradical fungal development was observed. Application of fenhexamid did not modify sterol profiles and the total colonization of roots. But the arbuscule frequency of the fungal partner was significantly affected. Comparison of the effects caused by the tested fungicides indicates that the usual phytosterols may be involved in symbiosis development. Indeed, observed modifications of root sterols composition could explain the high fenpropimorph toxicity to the AM symbiosis. However, the absence of sterolic modifications in the roots treated with fenhexamid could account for its more limited impact on mycorrhization.

  16. Exogenous Polyamines Improve Mycorrhizal Development And Growth And Flowering Of Freesia hybrida

    OpenAIRE

    Rezvanypour Shirin; Hatamzadeh Abdollah; Elahinia Seyed Ali; Asghari Hamid Reza

    2015-01-01

    An experiment was conducted in order to investigate the effects of exogenous polyamines (PAs) on the development of mycorrhizae in roots, nutrient uptake and vegetative and reproductive growth of Freesia hybrida ‘Golden Wave’. Corms of freesia were inoculated with Rhizophagus intraradices at sowing time and treated once a week by one of three PAs, putrescine (Put), spermidine or spermine, in concentrations of 0.05 and 0.1 mM each as foliar application or soil drench. Application of PAs, espec...

  17. Effect of poplar genotypes on mycorrhizal infection and secreted enzyme activities in mycorrhizal and non-mycorrhizal roots

    Science.gov (United States)

    Courty, P. E.; Labbé, J.; Kohler, A.; Marçais, B.; Bastien, C.; Churin, J. L.; Garbaye, J.; Le Tacon, F.

    2011-01-01

    The impact of ectomycorrhiza formation on the secretion of exoenzymes by the host plant and the symbiont is unknown. Thirty-eight F1 individuals from an interspecific Populus deltoides (Bartr.)×Populus trichocarpa (Torr. & A. Gray) controlled cross were inoculated with the ectomycorrhizal fungus Laccaria bicolor. The colonization of poplar roots by L. bicolor dramatically modified their ability to secrete enzymes involved in organic matter breakdown or organic phosphorus mobilization, such as N-acetylglucosaminidase, β-glucuronidase, cellobiohydrolase, β-glucosidase, β-xylosidase, laccase, and acid phosphatase. The expression of genes coding for laccase, N-acetylglucosaminidase, and acid phosphatase was studied in mycorrhizal and non-mycorrhizal root tips. Depending on the genes, their expression was regulated upon symbiosis development. Moreover, it appears that poplar laccases or phosphatases contribute poorly to ectomycorrhiza metabolic activity. Enzymes secreted by poplar roots were added to or substituted by enzymes secreted by L. bicolor. The enzymatic activities expressed in mycorrhizal roots differed significantly between the two parents, while it did not differ in non-mycorrhizal roots. Significant differences were found between poplar genotypes for all enzymatic activities measured on ectomycorrhizas except for laccases activity. In contrast, no significant differences were found between poplar genotypes for enzymatic activities of non-mycorrhizal root tips except for acid phosphatase activity. The level of enzymes secreted by the ectomycorrhizal root tips is under the genetic control of the host. Moreover, poplar heterosis was expressed through the enzymatic activities of the fungal partner. PMID:20881013

  18. Mycorrhizal aspects in slope stabilisation

    Science.gov (United States)

    Graf, Frank

    2016-04-01

    In order to re-colonise and stabilise slopes affected by superficial soil failure with plants essential requirements have to be met: the plants must grow the plants must survive sustainably plant succession must start and continuously develop These requirements, however, are anything but easy given, particularly under the often hostile environmental conditions dominating on bare and steep slopes. Mycorrhizal fungi, the symbiotic partners of almost all plants used in eco-engineering, are said to improve the plants' ability to overcome periods governed by strongly (growth) limiting factors. Subsequently, results of investigations are presented of mycorrhizal effects on different plant and soil functions related to eco-engineering in general and soil and slope stabilisation in particular. Generally, inoculation yielded higher biomass of the host plants above as well as below ground. Furthermore, the survival rate was higher for mycorrhized compared to non-mycorrhized plants, particularly under extreme environmental conditions. However, the scale of the mycorrhizal impact may be species specific of both the plant host as well as the fungal partner(s) and often becomes evident only after a certain time lag. Depending on the plant-fungus combination the root length per soil volume was found to be between 0 and 2.5 times higher for inoculated compared to non-inoculated specimens. On an alpine graded ski slope the survival of inoculated compared to non-treated Salix herbacea cuttings was significant after one vegetation period only for one of the three added mycorrhizal fungus species. However, after three years all of the inoculated plantlets performed significantly better than the non-inoculated controls. The analysis of the potential for producing and stabilising soil aggregates of five different ectomycorrhizal fungi showed high variation and, for the species Inocybe lacera, no significant difference compared to untreated soil. Furthermore, inoculation of Salix

  19. Influence of cover crops on citrus crops on arbuscular mycorrhizal fungi development in the Colombian piedmont Oxisols

    Directory of Open Access Journals (Sweden)

    Hernán Javier Monroy L.

    2013-01-01

    Full Text Available Native arbuscular mycorrhizal fungi associated with grassand legume cover crops established on Oxisol soils in the Colombian piedmont (Meta were identified morphologically and the ability to colonize was evaluated. The experimental area consisted of cover crops Arachispintoi (CIAT 18744, Brachiaria brizantha cv. Toledo, B. dictyoneura cv. Llanero, Desmodium ovalifolium c v. Maquenque, Panicum maximum (CIAT 36000, Paspalumnotatum, and a chemical control (Glyphosate and mechanical control established in the rows in a Valencia orange grove. The experiment followed a complete randomized block design (8 cover crops and three replications, evaluated during the wet and dry seasons. Rhizosphere soil and grass and legumes roots were sampled in order to identified AMF and quantify the number of spores and the percentage of colonization. A total of 26 species were identified, including Acaulosporascrobiculata, A. morrowiae and, Scutellospora heterogama, which accounted for over 65% of the population. Thepercentage of root colonization ranged between 47% and 94% with spore counts between 63 and 300/100 g of dry soil. Cover crops with the highest colonization percentage and AMF diversity were B. brizantha, B. dictyoneura and P. notatumin their respective order. Glyphosate and mechanical control had a negative influence on the sporulation and colonization of the arbuscular mycorrhizal fungi in the root system

  20. Does origin of mycorrhizal fungus on mycorrhizal plant influence effectiveness of the mycorrhizal symbiosis?

    NARCIS (Netherlands)

    Heijden, van der E.W.; Kuyper, T.W.

    2001-01-01

    Mycorrhizal effectiveness depends on the compatibility between fungus and plant. Therefore, genetic variation in plant and fungal species affect the effectiveness of the symbiosis. The importance of mycorrhizal plant and mycorrhizal fungus origin was investigated in two experiments. In the first

  1. Arbuscular mycorrhizal fungi and colonization stimulant in cotton and maize

    Directory of Open Access Journals (Sweden)

    Fabrício Henrique Moreira Salgado

    Full Text Available ABSTRACT: The objective of this study was to evaluate the effects of inoculation with different arbuscular mycorrhizal fungi native to Cerrado, associated with the application of colonization stimulant (7-hydroxy, 4’-methoxy-isoflavone at the initial growth of cotton and maize plants in a greenhouse. The experiment was carried out in a completely randomized design and 7x2 factorial scheme, with five species of arbuscular mycorrhizal fungi and combined inoculation (uniting all species in equal proportion and native fungi, in the presence and absence of colonization stimulant in maize and cotton crops. Shoots dry matter (SDM, roots dry matter (RDM, mycorrhizal colonization and accumulation of calcium, zinc and phosphorus in the SDM were evaluated at flowering. Inoculation of arbuscular mycorrhizal fungi and the use of colonization stimulant at low density of arbuscular mycorrhizal fungi propagules was beneficial to plant development. Inoculation with mycorrhizal fungi demonstrated different effects for the various parameters evaluated in cotton and maize, and the application of colonization stimulant promoted higher mycorrhizal colonization and initial growth in cotton, when associated with native AMF, and in corn, when associated with inoculation with Dentiscutata heterogama, Gigaspora margarita and Rhizophagus clarus.

  2. Order of arrival structures arbuscular mycorrhizal colonization of plants

    NARCIS (Netherlands)

    Werner, G.D.A.; Kiers, E.T.

    2015-01-01

    Priority effects - the impact of a species' arrival on subsequent community development - have been shown to influence species composition in many organisms. Whether priority effects among arbuscular mycorrhizal fungi (AMF) structure fungal root communities is not well understood. Here, we

  3. Plant hormones as signals in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Miransari, Mohammad; Abrishamchi, A; Khoshbakht, K; Niknam, V

    2014-06-01

    Arbuscular mycorrhizal (AM) fungi are non-specific symbionts developing mutual and beneficial symbiosis with most terrestrial plants. Because of the obligatory nature of the symbiosis, the presence of the host plant during the onset and proceeding of symbiosis is necessary. However, AM fungal spores are able to germinate in the absence of the host plant. The fungi detect the presence of the host plant through some signal communications. Among the signal molecules, which can affect mycorrhizal symbiosis are plant hormones, which may positively or adversely affect the symbiosis. In this review article, some of the most recent findings regarding the signaling effects of plant hormones, on mycorrhizal fungal symbiosis are reviewed. This may be useful for the production of plants, which are more responsive to mycorrhizal symbiosis under stress.

  4. Effects of root dips of benomyl and captan on seedling response and mycorrhizal development of outplanted longleaf, sand, and loblolly pines

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, G.E.

    1981-01-01

    Longleaf pine seedlings inoculated with Pisolithus tinctorius (Pt) on naturally inoculated (NI) were grown at densities of 7-1/2 or 15 per square feet. Seedlings were graded by size and ectomycorrhizal development. The Pt group at 7-1/2 per square feet had 50% ectomycorrhiza with 70% formed by Pt. In the Pt-15 per square foot group, 65% had ectomycorrhiza, 90% of which were Pt. The NI-7-1/2 per square foot group had 20% feeder root with ectomycorrhiza and the NI-15 per square foot had ectomycorrhiza in 30% of the feeder roots. A split-plot design was used to isolate Pt and NI treatments on major plots and 12 minor plots within each were represented by 25 seedlings. One experiment will determine the effect of removal of ectomycorrhiza (stripping) on seedling performance in the field. Preliminary observations indicate that stripping 50% or more of the mycorrhizae substantially reduces survival. Another experiment will test the effects of benomyl and captan as dips of fungicide/clay slurries on mycorrhizal development and seedling response. 2 tables. (MF)

  5. Comparative seed germination and seedling development of the ghost orchid, Dendrophylax lindenii (Orchidaceae), and molecular identification of its mycorrhizal fungus from South Florida.

    Science.gov (United States)

    Hoang, Nguyen H; Kane, Michael E; Radcliffe, Ellen N; Zettler, Lawrence W; Richardson, Larry W

    2017-02-01

    The endangered leafless ghost orchid, Dendrophylax lindenii, one of the most renowned orchids in the world, is difficult to grow under artificial conditions. Published information on asymbiotic and symbiotic (co-culture with a mycobiont) seed germination, seedling anatomy and developmental morphology of this leafless orchid is completely lacking. This information is critical for the development of efficient procedures for ghost orchid production for successful reintroduction. Ghost orchid seedling early development stages were morphologically and anatomically defined to compare germination, embryo and protocorm maturation and seedling development during asymbiotic and symbiotic culture with one of two mycorrhizal strains (Dlin-379 and Dlin-394) isolated from ghost orchid roots in situ KEY RESULTS: Seeds symbiotically germinated at higher rates when cultured with fungal strain Dlin-394 than with strain Dlin-379 or asymbiotically on P723 medium during a 10-week culture period. Fungal pelotons were observed in protocorm cells co-cultured with strain Dlin-394 but not Dlin-379. Some 2-year-old seedlings produced multinode inflorescences in vitro Production of keikis from inflorescence nodes indicated the capacity for clonal production in the ghost orchid. Ghost orchid embryo and seedling development were characterized into seven stages. Fungal strain Dlin-394 was confirmed as a possible ghost orchid germination mycobiont, which significantly promoted seed germination and seedling development. Internal transcribed spacer sequencing data confirmed that Dlin-394 belongs within the genus Ceratobasidium These results offer the opportunity to examine the benefits of using a mycobiont to enhance in vitro germination and possibly ex vitro acclimatization and sustainability following outplanting. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  6. 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.

  7. Expanding Genomics of Mycorrhizal Symbiosis

    Directory of Open Access Journals (Sweden)

    Alan eKuo

    2014-11-01

    Full Text Available The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant and soil health, and carbon and nutrient cycles. The symbiosis evolved repeatedly and independently as multiple morphological types (e.g. arbuscular [AM], ectomycorrhizal [ECM] in multiple fungal clades (e.g. phyla Glomeromycota, Ascomycota, Basidiomycota. The accessibility and culturability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first 3 mycorrhizal fungal genomes, representing 3 fungal phyla and 2 mycorrhizal types. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant-degrading enzymes (PDEs and expansion of lineage-specific gene families, including short secreted protein (SSP effectors and other symbiosis genes. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of gene families in contrast to Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other 2 fungi, the symbiosis can involve similar solutions as loss of PDEs and mycorrhiza-induced SSPs. The mycorrhizal community is building on these studies with 3 large-scale initiatives. The Mycorrhizal Genomics Initiative (MGI is sequencing 35 genomes of multiple fungal clades and mycorrhizal types for phylogenomic and population analyses. 17 MGI species whose symbiosis is reconstitutable in vitro are targeted for comprehensive transcriptomics of mycorrhiza formation. MGI genomes are seeding a set of 50+ reference fungal genomes for annotating metatranscriptomes sampled from 7 diverse well-described soil sites. These 3 projects address fundamental questions about the nature and role of a

  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. Regulatory networks underlying mycorrhizal development delineated by genome-wide expression profiling and functional analysis of the transcription factor repertoire of the plant symbiotic fungus Laccaria bicolor.

    Science.gov (United States)

    Daguerre, Y; Levati, E; Ruytinx, J; Tisserant, E; Morin, E; Kohler, A; Montanini, B; Ottonello, S; Brun, A; Veneault-Fourrey, C; Martin, F

    2017-09-18

    Ectomycorrhizal (ECM) fungi develop a mutualistic symbiotic interaction with the roots of their host plants. During this process, they undergo a series of developmental transitions from the running hyphae in the rhizosphere to the coenocytic hyphae forming finger-like structures within the root apoplastic space. These transitions, which involve profound, symbiosis-associated metabolic changes, also entail a substantial transcriptome reprogramming with coordinated waves of differentially expressed genes. To date, little is known about the key transcriptional regulators driving these changes, and the aim of the present study was to delineate and functionally characterize the transcription factor (TF) repertoire of the model ECM fungus Laccaria bicolor. We curated the L. bicolor gene models coding for transcription factors and assessed their expression and regulation in Poplar and Douglas fir ectomycorrhizae. We identified 285 TFs, 191 of which share a significant similarity with known transcriptional regulators. Expression profiling of the corresponding transcripts identified TF-encoding fungal genes differentially expressed in the ECM root tips of both host plants. The L. bicolor core set of differentially expressed TFs consists of 12 and 22 genes that are, respectively, upregulated and downregulated in symbiotic tissues. These TFs resemble known fungal regulators involved in the control of fungal invasive growth, fungal cell wall integrity, carbon and nitrogen metabolism, invasive stress response and fruiting-body development. However, this core set of mycorrhiza-regulated TFs seems to be characteristic of L. bicolor and our data suggest that each mycorrhizal fungus has evolved its own set of ECM development regulators. A subset of the above TFs was functionally validated with the use of a heterologous, transcription activation assay in yeast, which also allowed the identification of previously unknown, transcriptionally active yet secreted polypeptides designated

  10. Assembly, Annotation, and Analysis of Multiple Mycorrhizal Fungal Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Initiative Consortium, Mycorrhizal Genomics; Kuo, Alan; Grigoriev, Igor; Kohler, Annegret; Martin, Francis

    2013-03-08

    Mycorrhizal fungi play critical roles in host plant health, soil community structure and chemistry, and carbon and nutrient cycling, all areas of intense interest to the US Dept. of Energy (DOE) Joint Genome Institute (JGI). To this end we are building on our earlier sequencing of the Laccaria bicolor genome by partnering with INRA-Nancy and the mycorrhizal research community in the MGI to sequence and analyze dozens of mycorrhizal genomes of all Basidiomycota and Ascomycota orders and multiple ecological types (ericoid, orchid, and ectomycorrhizal). JGI has developed and deployed high-throughput sequencing techniques, and Assembly, RNASeq, and Annotation Pipelines. In 2012 alone we sequenced, assembled, and annotated 12 draft or improved genomes of mycorrhizae, and predicted ~;;232831 genes and ~;;15011 multigene families, All of this data is publicly available on JGI MycoCosm (http://jgi.doe.gov/fungi/), which provides access to both the genome data and tools with which to analyze the data. Preliminary comparisons of the current total of 14 public mycorrhizal genomes suggest that 1) short secreted proteins potentially involved in symbiosis are more enriched in some orders than in others amongst the mycorrhizal Agaricomycetes, 2) there are wide ranges of numbers of genes involved in certain functional categories, such as signal transduction and post-translational modification, and 3) novel gene families are specific to some ecological types.

  11. Effect of mycorrhizal inoculations on the growth of Shorea robusta seedlings

    Directory of Open Access Journals (Sweden)

    ASHWANI TAPWAL

    2015-05-01

    Full Text Available Tapwal A, Kumar R, Borah D. 2015. Effect of mycorrhizal inoculations on the growth of Shorea robusta seedlings. Nusantara Bioscience 7: 1-5. Shorea robusta is one of important timber yielding tree species of northeast India and known to have both ectomycorrhizal (EcM and endomycorrhizal (AM associations. It is hypothesized that under favorable conditions different mycorrhizal fungi present in soil develop symbiotic association with fine roots of trees. In present investigations, mycorrhizal inoculum of EcM and AM fungi applied to S. robusta seedlings raised in polyethylene bags in nursery. Observations on growth characters and mycorrhizal colonization were recorded at the interval of three months. The results revealed that irrespective of type of mycorrhizal inoculation, growth of the seedlings increased significantly in comparison to control. Maximum growth was observed for the seedlings inoculated with EcM alone, followed by dual inoculations (EcM+AM, seedlings inoculated with AM fungi and minimum in control.

  12. Role and influence of mycorrhizal fungi on radiocesium accumulation by plants

    Energy Technology Data Exchange (ETDEWEB)

    Dupre de Boulois, H. [Universite catholique de Louvain, Unite de Microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium); Joner, E.J. [Bioforsk Soil and Environment, FredrikA Dahls vei 20, N-1432 As (Norway); Leyval, C. [LIMOS, Nancy University, CNRS, Faculte des Sciences, BP239, 54506 Vandoeuvre-les-Nancy, Cedex (France); Jakobsen, I. [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Chen, B.D. [Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Roos, P. [Radiation Research Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Thiry, Y.; Rufyikiri, G. [Biosphere Impact Assessment, SCK.CEN, Foundation of Public Utility, 200 Boeretang, 2400 Mol (Belgium); Delvaux, B. [Universite catholique de Louvain, Unite des Sciences du Sol, Croix du Sud 2/10, 1348 Louvain-la-Neuve (Belgium); Declerck, S. [Universite catholique de Louvain, Unite de Microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium)], E-mail: declerck@mbla.ucl.ac.be

    2008-05-15

    This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies.

  13. Growth and Nutrient Uptake Responses of Kinnow to Vesicular Arbuscular Mycorrhizae

    OpenAIRE

    M.H. Shamshiri; K Usha; Bhupinder Singh

    2012-01-01

    In a field experiment, three-year-old Kinnow trees budded on Jatti Katti (C. jambhiri) rootstock were inoculated by three different arbuscular mycorrhiza (AM), Glomus manihotis (T1), Glomus mosseae (T2), and Gigaspora gigantia (T3), separately or in combination (T4). Microscopic assessment of AM colonization on Kinnow roots showed a relatively lower level of infection by different species when inoculated separately than when inoculaed together. Application of AM improved growth parameters lik...

  14. Vesicular-arbuscular mycorrhizae established with Glomus fasciculatus spores isolated from the feces of cricetine mice

    Science.gov (United States)

    Frederick M. Rothwell; Coleman Holt

    1978-01-01

    Cricetine mice were trapped on two revegetated surface-mined areas - one with a freshly seeded grass-legume cover and one with an early successional grass-forb cover. Chlamydospores of Glomus fasciculatus isolated from the feces of these animals produced representative endomycorrhizae with corn under greenhouse conditions.

  15. EFFECTS OF CORN CULTIVAR-TILLAGE SYSTEM COMBINATION ON VESICULAR ARBUSCULAR MYCORRHIZAE

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo .

    2011-10-01

    Full Text Available Pengaruh kombinasi  varietas jagung dan sistem olah tanah terhadap mikorisa vesikular arbuskular.  Penelitian telah dilakukan untuk mengevaluasi pengaruh kombinasi sistem olah tanah dan varietas terhadap  populasi mikorisa vesikular arbuskular. Penelitian juga ditujukan untuk mengetahui pengaruh kombinasi varietas jagung dan sistem olah tanah terhadap infeksi mikorisa vesicular arbuskular. Penelitian terdiri atas enam perlakuan yang disusun dalam rancangan acak kelompok. Perlakuan tersebut adalah varietas RR yang ditanam pada sistem olah tanah konservasi  (RRCT, varietas C7 yang ditanam pada sistem olah tanah konservasi (C7CT, varietas Bisma ditanam pada sistem olah tanah konservasi (BCT, varietas RR ditanam pada sistem olah tanah sempurna (RRFT, varietas C7 yang ditanam pada sistem olah tanah sempurna (C7FT, dan varietas Bisma ditanam pada sistem olah tanah sempurna (BFT. Hasil penelitian pada sistem olah tanah konservasi  menunjukkan bahwa varietas RR dan C7 secara nyata dapat menurunkan infeksi mikorisa dibandingkan dengan varietas Bisma. Hasil penelitian juga menunjukkan bahwa pada varietas RR dan C7, olah tanah konservasi secara nyata menurunkan infeksi mikorisa dibandingkan dengan sistem olah tanah sempurna.

  16. Increasing Growth and Yield of Upland Rice by Application of Vesicular Arbuscular Mycorrhizae and Potassium Fertilizer

    Directory of Open Access Journals (Sweden)

    Dedi Natawijaya

    2012-01-01

    Full Text Available Field experiment with a split plot design has been carried out in order to assess the growth characteristics andyields, and effectiveness of MVA upland rice which were given potassium fertilizer in two growing seasons. MVAinoculation consisted of three treatments (without MVA, Glomus sp. and Gigaspora sp. while potassium fertilizerconsisted of five levels (0, 12.5, 25, 37.5, and 50 kg ha-1 K. The results showed that plant growth variable which wasinoculated by MVA at any levels of K fertilizer was higher in the dry season than that in the wet season, whereas theopposite occurred for net assimilation rate. Potassium content of leaf tissue, shoot/root ratio, and grain weight perhill was determined and mutually dependent on genus MVA, dosages of K fertilizer, and growing season. Harvestindex and grain dry weight per hill were influenced by the growing season and the genus MVA but the effect did notdepend on each other. At all dosages of K fertilizer and any MVA genera, Gigaspora sp. inoculation was better thanthat of Glomus sp. Dry weight of grains per hill was affected by the contribution of grain content per hill, weight of1000 grains and number of productive seedlings per hill. The optimum dosage of K fertilizer in the dry season was32.4 kg ha-1 K with grain yield 3.12 Mg ha-1 for inoculation of Gigaspora sp., whereas the optimum dosage in the wetseason was 34.2 kg ha-1 K for the treatment Glomus sp. inoculation with Gigaspora sp. in the wet season did notreach dosages of optimum K fertilizer.

  17. Effects of vesicular-arbuscular mycorrhizae and seed source on nursery-grown black walnut seedlings

    Science.gov (United States)

    B. L. Brookshire; H. E. Garrett; T. L. Robison

    2003-01-01

    A nursery study was established in Missouri to evaluate the effects of endomycorrhizal inoculation and seed source on the growth of black walnut seedlings. Inoculation, in general, resulted in seedlings with significantly larger sturdiness quotients. Glomus intraradicies was found to produce larger seedlings than Glomus etunicatus...

  18. Mycorrhizal fungi suppress aggressive Agricultural weeds.

    NARCIS (Netherlands)

    Rinaudo, V.; Barberi, P.; Giovannetti, M.; van der Heijden, M.G.A.

    2010-01-01

    Plant growth responses to arbuscular mycorrhizal fungi (AMF) are highly variable, ranging from mutualism in a wide range of plants, to antagonism in some non-mycorrhizal plant species and plants characteristic of disturbed environments. Many agricultural weeds are non mycorrhizal or originate from

  19. Expanding genomics of mycorrhizal symbiosis.

    Science.gov (United States)

    Kuo, Alan; Kohler, Annegret; Martin, Francis M; Grigoriev, Igor V

    2014-01-01

    The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant nutrition, soil health, and carbon cycling. The symbiosis evolved repeatedly and independently as multiple morphotypes [e.g., arbuscular mycorrhizae (AM), ectomycorrhizal (ECM)] in multiple fungal clades (e.g., phyla Glomeromycota, Ascomycota, Basidiomycota). The accessibility and cultivability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first three mycorrhizal fungal genomes, representing two morphotypes and three phyla. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant cell wall-degrading enzymes (PCWDEs) and expansion of lineage-specific gene families such as short secreted protein (SSP) effectors. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of families as in Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other two fungi, symbiosis can involve similar solutions as symbiosis-induced SSPs and loss of PCWDEs. The three genomes provide a solid base for addressing fundamental questions about the nature and role of a vital mutualism.

  20. Diversity and Plant Growth Promoting Properties of Rhizobacteria ...

    African Journals Online (AJOL)

    characteristics of plant growth promoting rhizobacteria (PGPR) and hence selected for further study. The sixty six isolates were further ... microorganisms as inoculum to boost production of the crop could be one of the potential ... vesicular arbuscular mycorrhizal (VAM) fungi (Glomus fasiculatum) on mineral content of tef.

  1. Browse Title Index

    African Journals Online (AJOL)

    Items 3951 - 4000 of 11090 ... Vol 10, No 36 (2011), Effect of vermicompost on manifestation of pesticide action on growth of Zinnia elegans, Abstract PDF. AK Sharan, M Kumar, R Singh, AK Neha, GD Sharma, C Jee. Vol 7, No 19 (2008), Effect of vesicular arbuscular mycorrhizal fungus on the physiological and biochemical ...

  2. Browse Title Index

    African Journals Online (AJOL)

    Items 151 - 200 of 444 ... Vol 24 (1991), Effects of nitrate and ammonium nitrogen on vesicular-arbuscular mycorrhizal infection in letttuce (Lactuca sativa) grown in sand with nutrient solutions, Abstract. E Owusu-Benoah. Vol 20 (1987), Effects of N-nitrate fertilization on yield and dinitrogen fixation in common bean (Phaseolus ...

  3. Author Details

    African Journals Online (AJOL)

    Owusu-Benoah, E. Vol 24 (1991) - Articles Effects of nitrate and ammonium nitrogen on vesicular-arbuscular mycorrhizal infection in letttuce (Lactuca sativa) grown in sand with nutrient solutions. Abstract. ISSN: 0855-0042. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

  4. Root hydraulic conductivity and xylem sap levels of zeatin riboside and abscisic acid in ectomycorrhizal Douglas fir seedlings

    Science.gov (United States)

    Mark D. Coleman; Caroline S. Bledsoe; Barbara A. Smit

    1990-01-01

    Mechanistic hypotheses to explain mycorrhizal enhancement of root hydraulic conductivity (Lp) suggest that phosphorus (P) nutrition, plant growth substances and/or altered morphology may be responsible. Such ideas are based on work with VA (vesicular-arbuscular) mycorrhizas. Since VA mycorrhizas and ectomycorrhizas differ in many respects, they...

  5. Effect of manganese on endomycorrhizal sugar maple seedlings

    Science.gov (United States)

    George A. Schier; Carolyn J. McQuattie

    2002-01-01

    Manganese (Mn) toxicity may play an important role in the poor survival of seedlings in declining sugar maple (Acer saccharum Marsh.) stands in northern Pennsylvania. To determine the effect of Mn on the growth of sugar maple seedlings, 1-year-old seedlings inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi and growing in sand-vermiculite-...

  6. (VAM) and phosphate solubilizing bacteria (PSB)

    African Journals Online (AJOL)

    User

    2013-09-18

    Sep 18, 2013 ... potash mobilizing and plant promoting microorganisms. Vesicular arbuscular mycorrhizal (VAM) fungi improve plant growth through phosphorous nutrition. In addition to phosphorous, they also help in the uptake of other nutri- ent elements. Nutrient absorption by fungal symbionts is due to external hyphae ...

  7. Insights on the Impact of Arbuscular Mycorrhizal Symbiosis on Tomato Tolerance to Water Stress

    National Research Council Canada - National Science Library

    Chitarra, Walter; Pagliarani, Chiara; Maserti, Biancaelena; Lumini, Erica; Siciliano, Ilenia; Cascone, Pasquale; Schubert, Andrea; Gambino, Giorgio; Balestrini, Raffaella; Guerrieri, Emilio

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development...

  8. Arbuscular mycorrhizal fungi in terms of symbiosis-parasitism continuum.

    Science.gov (United States)

    Schmidt, B; Gaşpar, S; Camen, D; Ciobanu, I; Sumălan, R

    2011-01-01

    Arbuscular mycorrhizal fungi are forming the most wide-spread mycorrhizal relationships on Earth. Mycorrhiza contributes to phosphorous acquisition, water absorption and resistance to diseases. The fungus promotes the absorption of nutrients and water from soil, meanwhile the host plant offers photosynthetic assimilates in exchange, like carbohydrates, as energy source. The plant benefits from the contribution of symbiotic partner only when nutrients are in low concentrations in soil and the root system would not be able to absorb sufficiently the minerals. When the help of mycorrhizal fungi is not necessarily needed, the host plant is making an economy of energy, suppressing the development of fungi in the internal radicular space. In this moment, the nature of relationship turns from symbiotic to parasitic, triggering a series of defensive reactions from the plant. Also, there were several cases reported when the presence of arbuscular mycorrhizal fungi negatively influenced the host plant. For example, in adverse environmental conditions, like very high temperatures, instead of determining a higher plant biomass and flowering, the mycorrhiza reduces the growth of the host plant. We conducted a pot experiment with hydroponic culture to examine the effect of arbuscular mycorrhiza on development of French marigold as a host plant. As experimental variants, the phosphorous content in nutrient medium and temperature varied. Plants were artificially infected with arbuscular mycorrhizal fungi using a commercial inoculum containing three fungal species, as following: Glomus intraradices, Glomus etunicatum and Glomus claroideum. Colonization intensity and arbuscular richness were checked using root staining with aniline blue and estimation with the Trouvelot method. To observe the differences between plants from the experimental variants, we examined the number of side shoots, flower buds and fully developed flowers, fresh biomass and total leaf area. Results show that

  9. Arbuscular mycorrhizal fungi in alleviation of salt stress: a review.

    Science.gov (United States)

    Evelin, Heikham; Kapoor, Rupam; Giri, Bhoopander

    2009-12-01

    Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways. This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress. The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K(+) : Na(+) ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na(+)/H(+) antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultra-structural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes.

  10. 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.

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

    Science.gov (United States)

    Nouri, Eva; Breuillin-Sessoms, Florence; Feller, Urs; Reinhardt, Didier

    2014-01-01

    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.

  12. Phylogenetic and microsatellite markers for Tulasnella (Tulasnellaceae) mycorrhizal fungi associated with Australian orchids.

    Science.gov (United States)

    Ruibal, Monica P; Peakall, Rod; Smith, Leon M; Linde, Celeste C

    2013-03-01

    Phylogenetic and microsatellite markers were developed for Tulasnella mycorrhizal fungi to investigate fungal species identity and diversity. These markers will be useful in future studies investigating the phylogenetic relationship of the fungal symbionts, specificity of orchid-mycorrhizal associations, and the role of mycorrhizae in orchid speciation within several orchid genera. • We generated partial genome sequences of two Tulasnella symbionts originating from Chiloglottis and Drakaea orchid species with 454 genome sequencing. Cross-genus transferability across mycorrhizal symbionts associated with multiple genera of Australian orchids (Arthrochilus, Chiloglottis, Drakaea, and Paracaleana) was found for seven phylogenetic loci. Five loci showed cross-transferability to Tulasnella from other orchid genera, and two to Sebacina. Furthermore, 11 polymorphic microsatellite loci were developed for Tulasnella from Chiloglottis. • Highly informative markers were obtained, allowing investigation of mycorrhizal diversity of Tulasnellaceae associated with a wide variety of terrestrial orchids in Australia and potentially worldwide.

  13. Phylogenetic and Microsatellite Markers for Tulasnella (Tulasnellaceae Mycorrhizal Fungi Associated with Australian Orchids

    Directory of Open Access Journals (Sweden)

    Monica P. Ruibal

    2013-03-01

    Full Text Available Premise of the study: Phylogenetic and microsatellite markers were developed for Tulasnella mycorrhizal fungi to investigate fungal species identity and diversity. These markers will be useful in future studies investigating the phylogenetic relationship of the fungal symbionts, specificity of orchid–mycorrhizal associations, and the role of mycorrhizae in orchid speciation within several orchid genera. Methods and Results: We generated partial genome sequences of two Tulasnella symbionts originating from Chiloglottis and Drakaea orchid species with 454 genome sequencing. Cross-genus transferability across mycorrhizal symbionts associated with multiple genera of Australian orchids (Arthrochilus, Chiloglottis, Drakaea, and Paracaleana was found for seven phylogenetic loci. Five loci showed cross-transferability to Tulasnella from other orchid genera, and two to Sebacina. Furthermore, 11 polymorphic microsatellite loci were developed for Tulasnella from Chiloglottis. Conclusions: Highly informative markers were obtained, allowing investigation of mycorrhizal diversity of Tulasnellaceae associated with a wide variety of terrestrial orchids in Australia and potentially worldwide.

  14. The arbuscular mycorrhizal fungus Rhizophagus irregularis differentially regulates the copper response of two maize cultivars differing in copper tolerance.

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    Merlos, Miguel A; Zitka, Ondrej; Vojtech, Adam; Azcón-Aguilar, Concepción; Ferrol, Nuria

    2016-12-01

    Arbuscular mycorrhiza can increase plant tolerance to heavy metals. The effects of arbuscular mycorrhiza on plant metal tolerance vary depending on the fungal and plant species involved. Here, we report the effect of the arbuscular mycorrhizal fungus Rhizophagus irregularis on the physiological and biochemical responses to Cu of two maize genotypes differing in Cu tolerance, the Cu-sensitive cv. Orense and the Cu-tolerant cv. Oropesa. Development of the symbiosis confers an increased Cu tolerance to cv. Orense. Root and shoot Cu concentrations were lower in mycorrhizal than in non-mycorrhizal plants of both cultivars. Shoot lipid peroxidation increased with soil Cu content only in non-mycorrhizal plants of the Cu-sensitive cultivar. Root lipid peroxidation increased with soil Cu content, except in mycorrhizal plants grown at 250mg Cu kg-1soil. In shoots of mycorrhizal plants of both cultivars, superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase activities were not affected by soil Cu content. In Cu-supplemented soils, total phytochelatin content increased in shoots of mycorrhizal cv. Orense but decreased in cv. Oropesa. Overall, these data suggest that the increased Cu tolerance of mycorrhizal plants of cv. Orense could be due to an increased induction of shoot phytochelatin biosynthesis by the symbiosis in this cultivar. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Untangling above- and belowground mycorrhizal fungal networks in tropical orchids.

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    Leake, J R; Cameron, D D

    2012-10-01

    Orchids typically depend on fungi for establishment from seeds, forming mycorrhizal associations with basidiomycete fungal partners in the polyphyletic group rhizoctonia from early stages of germination, sometimes with very high specificity. This has raised important questions about the roles of plant and fungal phylogenetics, and their habitat preferences, in controlling which fungi associate with which plants. In this issue of Molecular Ecology, Martos et al. (2012) report the largest network analysis to date for orchids and their mycorrhizal fungi, sampling a total of over 450 plants from nearly half the 150 tropical orchid species on Reunion Island, encompassing its main terrestrial and epiphytic orchid genera. The authors found a total of 95 operational taxonomic units of mycorrhizal fungi and investigated the architecture and nestedness of their bipartite networks with 73 orchid species. The most striking finding was a major ecological barrier between above- and belowground mycorrhizal fungal networks, despite both epiphytic and terrestrial orchids often associating with closely related taxa across all three major lineages of rhizoctonia fungi. The fungal partnerships of the epiphytes and terrestrial species involved a diversity of fungal taxa in a modular network architecture, with only about one in ten mycorrhizal fungi partnering orchids in both groups. In contrast, plant and fungal phylogenetics had weak or no effects on the network. This highlights the power of recently developed ecological network analyses to give new insights into controls on plant-fungal symbioses and raises exciting new hypotheses about the differences in properties and functioning of mycorrhiza in epiphytic and terrestrial orchids. © 2012 Blackwell Publishing Ltd.

  16. Mycorrhizal fungi associated with Taiwanese Pyrola morrisonensis (Ericaceae in a naturally regenerated forest

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    Yosuke MATSUDA

    2017-11-01

    Full Text Available Pyrola morrisonensis, an evergreen herb in the family Ericaceae, is endemic to Taiwan. We examined mycorrhizal development and the associated fungi in this species. Nine plants were collected in a naturally regenerated forest in central Taiwan. The plants were genetically identical in their internal transcribed spacer (ITS region, and their sequences matched the known sequence for P. morrisonensis. Fine roots of each plant were colonized by mycorrhizal fungi that formed mycorrhizas either with or without fungal mantles. DNA sequences of the ITS region of these fungi suggested that they belonged to mycorrhizal taxa that are common tree symbionts. Among them, members of Thelephoraceae were the dominant taxon in the host plants. These results indicate that P. morrisonensis is intimately associated with mycorrhizal fungi that might also connect with neighboring trees.

  17. Mycorrhizal diversity in the rhizosphere of sugarcane and grass on different soil types

    Science.gov (United States)

    Ratri Cahyani, Vita; Rastikawati, Dewi; Yuniardi, Nestri; Syamsiyah, Jauhari; Suntoro

    2017-11-01

    Mycorrhiza has been known well as beneficial microbiota for supporting plant growth and production. Understanding of the variability and the consistency of the mycorrhizal diversity on various habitats is important for developing mycorrhizal utilization. Mycorrhizal diversity in the rhizosphere of sugarcane from 4 (four) soil types and the rhizosphere of grass from 3 (three) soil types were investigated in the present study. The results showed that Glomus indicated as a versatile genus because it was found as a common and dominant genus in the sugarcane rhizosphere on all of four soil types (Alfisol, Andisol, Inceptisol, Vertisol) and in the grass rhizosphere on all of three soil types (Ultisol, Oxisol, Histosol). In addition, Acaulospora was found as a common genus in grass rhizosphere. Statistical analysis indicated that P availability in the rhizosphere of sugarcane had a significantly negative correlation with mycorrhizal spore density, in which decreasing P availability significantly related with increasing spore density.

  18. Cellular programs for arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Harrison, Maria J

    2012-12-01

    In arbuscular mycorrhizal (AM) symbiosis, AM fungi colonize root cortical cells to obtain carbon from the plant, while assisting the plant with the acquisition of mineral nutrients from the soil. Within the root cells, the fungal hyphae inhabit membrane-bound compartments that the plant establishes to accommodate the fungal symbiont. Recent data provide new insights into the events associated with development of the symbiosis including signaling for the formation of a cellular apparatus that guides hyphal growth through the cell. Plant genes that play key roles in a cellular program for the accommodation of microbial symbionts have been identified. In the inner cortical cells, tightly regulated changes in gene expression accompanied by a transient reorientation of secretion, enables the cell to build and populate the periarbuscular membrane with its unique complement of transporter proteins. Similarities between the cellular events for development of the periarbuscular membrane and cell plate formation are emerging. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Role of arbuscular mycorrhizal symbiosis in root mineral uptake under CaCO3 stress.

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    Labidi, Sonia; Ben Jeddi, Fayçal; Tisserant, Benoit; Debiane, Djouher; Rezgui, Salah; Grandmougin-Ferjani, Anne; Lounès-Hadj Sahraoui, Anissa

    2012-07-01

    This study investigated the effects of increasing CaCO(3) concentrations (0, 5, 10, 20 mM) on arbuscular mycorrhizal (AM) symbiosis establishment as well as on chicory root growth and mineral nutrient uptake in a monoxenic system. Although CaCO(3) treatments significantly decreased root growth and altered the symbiosis-related development steps of the AM fungus Rhizophagus irregularis (germination, germination hypha elongation, root colonization rate, extraradical hyphal development, sporulation), the fungus was able to completely fulfill its life cycle. Even when root growth decreased more drastically in mycorrhizal roots than in non-mycorrhizal ones in the presence of high CaCO(3) levels, the AM symbiosis was found to be beneficial for root mineral uptake. Significant increases in P, N, Fe, Zn and Cu concentrations were recorded in the mycorrhizal roots. Whereas acid and alkaline phosphatase enzymatic activities remained constant in mycorrhizal roots, they were affected in non-mycorrhizal roots grown in the presence of CaCO(3) when compared with the control.

  20. The mycorrhizal type governs root exudation and nitrogen uptake of temperate tree species.

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    Liese, Rebecca; Lübbe, Torben; Albers, Nora W; Meier, Ina C

    2017-11-08

    Even though the two dominant mycorrhizal associations of temperate tree species differentially couple carbon (C) and nitrogen (N) cycles in temperate forests, systematic differences between the biogeochemical cycles of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species remain poorly described. A classification according to the mycorrhizal type offers the chance, though, to develop a global frame concept for the prediction of temperate ecosystem responses to environmental change. Focusing on the influence of mycorrhizal types on two key plant processes of biogeochemical cycling (root exudation and N acquisition), we investigated four temperate deciduous tree species per mycorrhizal type in a drought experiment in large mesocosms. We hypothesized that (H1) C loss by root exudation is higher in ECM than in AM trees, (H2) drought leads to higher reductions in root exudation of drought-sensitive ECM trees and (H3) inorganic N uptake is higher in AM than in ECM trees. In contradiction to H2, we found no systematic difference in root exudation between the mycorrhizal types at ample soil moisture, but almost twofold higher exudation in ECM trees when exposed to soil drought. In addition, photosynthetic C cost of root exudation strongly increased by ~10-fold in drought-treated ECM trees, while it only doubled in AM trees, which confirms H1. With respect to H3, we corroborated that AM trees had higher absolute and relative inorganic N acquisition rates than ECM trees, while the organic N uptake did not differ between mycorrhizal types. We conclude that ECM trees are less efficient in inorganic N uptake than AM trees, but ECM trees increase root C release as an adaptive response to dry soil to maintain hydraulic conductivity and/or nutrient availability. These systematic differences in key biogeochemical processes support hints on the key role of the mycorrhizal types in coupling C and N cycles in temperate forests. © The Author 2017. Published by Oxford

  1. Model systems to unravel the molecular mechanisms of heavy metal tolerance in the ericoid mycorrhizal symbiosis.

    Science.gov (United States)

    Daghino, Stefania; Martino, Elena; Perotto, Silvia

    2016-05-01

    Ericoid mycorrhizal plants dominate in harsh environments where nutrient-poor, acidic soil conditions result in a higher availability of potentially toxic metals. Although metal-tolerant plant species and ecotypes are known in the Ericaceae, metal tolerance in these plants has been mainly attributed to their association with ericoid mycorrhizal fungi. The mechanisms underlying plant protection by the fungal symbiont are poorly understood, whereas some insights have been achieved regarding the molecular mechanisms of heavy metal tolerance in the fungal symbiont. This review will briefly introduce the general features of heavy metal tolerance in mycorrhizal fungi and will then focus on the use of "omics" approaches and heterologous expression in model organisms to reveal the molecular bases of fungal response to heavy metals. Functional complementation in Saccharomyces cerevisiae has allowed the identification of several ericoid mycorrhizal fungi genes (i.e., antioxidant enzymes, metal transporters, and DNA damage repair proteins) that may contribute to metal tolerance in a metal-tolerant ericoid Oidiodendron maius isolate. Although a powerful system, the use of the yeast complementation assay to study metal tolerance in mycorrhizal symbioses has limitations. Thus, O. maius has been developed as a model system to study heavy metal tolerance mechanisms in mycorrhizal fungi, thanks to its high metal tolerance, easy handling and in vitro mycorrhization, stable genetic transformation, genomics, transcriptomic and proteomic resources.

  2. Metagenomic Analyses of the Viruses Detected in Mycorrhizal Fungi and Their Host Orchid.

    Science.gov (United States)

    Shimura, Hanako; Masuta, Chikara; Koda, Yasunori

    2018-01-01

    In nature, mycorrhizal association with soilborne fungi is indispensable for orchid families. Fungal structures from compatible endo-mycorrhizal fungi in orchid cells are digested in cells to be supplied to orchids as nutrition. Because orchid seeds lack the reserves for germination, they keep receiving nutrition through mycorrhizal formation from seed germination until shoots develop (leaves) and become photoautotrophic. Seeds of all orchid species surely geminate with the help of their own fungal partners, and this specific partnership has been acquired for a long evolutional history between orchids and fungi.We have studied the interactions between orchids and mycorrhizal fungi and recently conducted transcriptome analyses (RNAseq) by a next-generation sequencing (NGS) approach. It is possible that orchid RNA isolated form naturally grown plants is contaminated with RNAs derived from mycorrhizal fungi in the orchid cells. To avoid such contamination, we here prepared aseptically germinated orchid plants (i.e., fungus-free plants) together with a pure-cultured fungal isolate and field-growing orchid samples. In the cDNA library prepared from orchid and fungal tissues, we found that partitivirus-like sequences were common in an orchid and its mycorrhizal fungus. These partitivirus-like sequences were closely related by a phylogenetic analysis, suggesting that transmission of an ancestor virus between the two organisms occurred through the specific relation of the orchid and its associated fungus.

  3. Mycorrhizal status helps explain invasion success of alien plant species.

    Science.gov (United States)

    Menzel, Andreas; Hempel, Stefan; Klotz, Stefan; Moora, Mari; Pyšek, Petr; Rillig, Matthias C; Zobel, Martin; Kühn, Ingolf

    2017-01-01

    It is still debated whether alien plants benefit from being mycorrhizal, or if engaging in the symbiosis constrains their establishment and spread in new regions. We analyzed the association between mycorrhizal status of alien plant species in Germany and their invasion success. We compared whether the representation of species with different mycorrhizal status (obligate, facultative, or non-mycorrhizal) differed at several stages of the invasion process. We used generalized linear models to explain the occupied geographical range of alien plants, incorporating interactions of mycorrhizal status with plant traits related to morphology, reproduction, and life-history. Non-naturalized aliens did not differ from naturalized aliens in the relative frequency of different mycorrhizal status categories. Mycorrhizal status significantly explained the occupied range of alien plants; with facultative mycorrhizal species inhabiting a larger range than non-mycorrhizal aliens and obligate mycorrhizal plant species taking an intermediate position. Aliens with storage organs, shoot metamorphoses, or specialized structures promoting vegetative dispersal occupied a larger range when being facultative mycorrhizal. We conclude that being mycorrhizal is important for the persistence of aliens in Germany and constitutes an advantage compared to being non-mycorrhizal. Being facultative mycorrhizal seems to be especially advantageous for successful spread, as the flexibility of this mycorrhizal status may enable plants to use a broader set of ecological strategies. © 2016 by the Ecological Society of America.

  4. 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)

  5. Effects of arbuscular mycorrhizal fungi on seedling growth and development of two wetland plants, Bidens frondosa L., and Eclipta prostrata (L.) L., grown under three levels of water availability.

    Science.gov (United States)

    Stevens, Kevin J; Wall, Christopher B; Janssen, Joel A

    2011-05-01

    To identify the importance of arbuscular mycorrhizal fungi (AMF) colonizing wetland seedlings following flooding, we assessed the effects of AMF on seedling establishment of two pioneer species, Bidens frondosa and Eclipta prostrata grown under three levels of water availability and ask: (1) Do inoculated seedlings differ in growth and development from non-inoculated plants? (2) Are the effects of inoculation and degree of colonization dependent on water availability? (3) Do plant responses to inoculation differ between two closely related species? Inoculation had no detectable effects on shoot height, or plant biomass but did affect biomass partitioning and root morphology in a species-specific manner. Shoot/root ratios were significantly lower in non-inoculated E. prostrata plants compared with inoculated plants (0.381 ± 0.066 vs. 0.683 ± 0.132). Root length and surface area were greater in non-inoculated E. prostrata (259.55 ± 33.78 cm vs. 194.64 ± 27.45 cm and 54.91 ± 7.628 cm(2) vs. 46.26 ± 6.8 cm(2), respectively). Inoculation had no detectable effect on B. frondosa root length, volume, or surface area. AMF associations formed at all levels of water availability. Hyphal, arbuscular, and vesicular colonization levels were greater in dry compared with intermediate and flooded treatments. Measures of mycorrhizal responsiveness were significantly depressed in E. prostrata compared with B. frondosa for total fresh weight (-0.3 ± 0.18 g vs. 0.06 ± 0.06 g), root length (-0.78 ± 0.28 cm vs.-0.11 ± 0.07 cm), root volume (-0.49 ± 0.22 cm(3) vs. 0.06 ± 0.07 cm(3)), and surface area (-0.59 ± 0.23 cm(2) vs.-0.03 ± 0.08 cm(2)). Given the disparity in species response to AMF inoculation, events that alter AMF prevalence in wetlands could significantly alter plant community structure by directly affecting seedling growth and development.

  6. Cell wall remodeling in mycorrhizal symbiosis: a way towards biotrophism

    Science.gov (United States)

    Balestrini, Raffaella; Bonfante, Paola

    2014-01-01

    Cell walls are deeply involved in the molecular talk between partners during plant and microbe interactions, and their role in mycorrhizae, i.e., the widespread symbiotic associations established between plant roots and soil fungi, has been investigated extensively. All mycorrhizal interactions achieve full symbiotic functionality through the development of an extensive contact surface between the plant and fungal cells, where signals and nutrients are exchanged. The exchange of molecules between the fungal and the plant cytoplasm takes place both through their plasma membranes and their cell walls; a functional compartment, known as the symbiotic interface, is thus defined. Among all the symbiotic interfaces, the complex intracellular interface of arbuscular mycorrhizal (AM) symbiosis has received a great deal of attention since its first description. Here, in fact, the host plasma membrane invaginates and proliferates around all the developing intracellular fungal structures, and cell wall material is laid down between this membrane and the fungal cell surface. By contrast, in ectomycorrhizae (ECM), where the fungus grows outside and between the root cells, plant and fungal cell walls are always in direct contact and form the interface between the two partners. The organization and composition of cell walls within the interface compartment is a topic that has attracted widespread attention, both in ecto- and endomycorrhizae. The aim of this review is to provide a general overview of the current knowledge on this topic by integrating morphological observations, which have illustrated cell wall features during mycorrhizal interactions, with the current data produced by genomic and transcriptomic approaches. PMID:24926297

  7. 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

  8. Low specificity and nested subset structure characterize mycorrhizal associations in five closely related species of the genus Orchis.

    Science.gov (United States)

    Jacquemyn, Hans; Honnay, Olivier; Cammue, Bruno P A; Brys, Rein; Lievens, Bart

    2010-09-01

    Most orchid species rely on mycorrhizae to complete their life cycle. Despite a growing body of literature identifying orchid mycorrhizal associations, the nature and specificity of the association between orchid species and mycorrhizal fungi remains largely an open question. Nonetheless, better insights into these obligate plant-fungus associations are indispensable for understanding the biology and conservation of orchid populations. To investigate orchid mycorrhizal associations in five species of the genus Orchis (O. anthropophora, O. mascula, O. militaris, O. purpurea, and O. simia), we developed internal transcribed spacer-based DNA arrays from extensive clone library sequence data sets, enabling rapid and simultaneous detection of a wide range of basidiomycetous mycorrhizal fungi. A low degree of specificity was observed, with two orchid species associating with nine different fungal partners. Phylogenetic analysis revealed that the majority of Orchis mycorrhizal fungi are members of the Tulasnellaceae, but in some plants, members of the Thelephoraceae, Cortinariaceae and Ceratobasidiaceae were also found. In all species except one (O. mascula), individual plants associated with more than one fungus simultaneously, and in some cases, associations with ≥3 mycorrhizal fungi at the same time were identified. Nestedness analysis showed that orchid mycorrhizal associations were significantly nested, suggesting asymmetric specialization and a dense core of interactions created by symmetric interactions between generalist species. Our results add support to the growing literature that multiple associations may be common among orchids. Low specificity or preference for a widespread fungal symbiont may partly explain the wide distribution of the investigated species. © 2010 Blackwell Publishing Ltd.

  9. Saprotrophic fungal mycorrhizal symbionts in achlorophyllous orchids

    Science.gov (United States)

    Martos, Florent; Perry, Brian A; Padamsee, Mahajabeen; Roy, Mélanie; Pailler, Thierry

    2010-01-01

    Mycoheterotrophic plants are achlorophyllous plants that obtain carbon from their mycorrhizal fungi. They are usually considered to associate with fungi that are (1) specific of each mycoheterotrophic species and (2) mycorrhizal on surrounding green plants, which are the ultimate carbon source of the entire system. Here we review recent works revealing that some mycoheterotrophic plants are not fungal-specific, and that some mycoheterotrophic orchids associate with saprophytic fungi. A re-examination of earlier data suggests that lower specificity may be less rare than supposed in mycoheterotrophic plants. Association between mycoheterotrophic orchids and saprophytic fungi arose several times in the evolution of the two partners. We speculate that this indirectly illustrates why transition from saprotrophy to mycorrhizal status is common in fungal evolution. Moreover, some unexpected fungi occasionally encountered in plant roots should not be discounted as ‘molecular scraps’, since these facultatively biotrophic encounters may evolve into mycorrhizal symbionts in some other plants. PMID:20061806

  10. 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.

  11. Signaling in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Harrison, Maria J

    2005-01-01

    Many microorganisms form symbioses with plants that range, on a continuous scale, from parasitic to mutualistic. Among these, the most widespread mutualistic symbiosis is the arbuscular mycorrhiza, formed between arbuscular mycorrhizal (AM) fungi and vascular flowering plants. These associations occur in terrestrial ecosystems throughout the world and have a global impact on plant phosphorus nutrition. The arbuscular mycorrhiza is an endosymbiosis in which the fungus inhabits the root cortical cells and obtains carbon provided by the plant while it transfers mineral nutrients from the soil to the cortical cells. Development of the symbiosis involves the differentiation of both symbionts to create novel symbiotic interfaces within the root cells. The aim of this review is to explore the current understanding of the signals and signaling pathways used by the symbionts for the development of the AM symbiosis. Although the signal molecules used for initial communication are not yet known, recent studies point to their existence. Within the plant, there is evidence of arbuscular mycorrhiza-specific signals and of systemic signaling that influences phosphate-starvation responses and root development. The landmark cloning of three plant signaling proteins required for the development of the symbiosis has provided the first insights into a signaling pathway that is used by AM fungi and by rhizobia for their symbiotic associations with legumes.

  12. Effect of high soil copper concentration on mycorrhizal grapevines

    Science.gov (United States)

    Nogales, Amaia; Santos, Erika S.; Viegas, Wanda; Aran, Diego; Pereira, Sofia H.; Vidigal, Patricia; Lopes, Carlos M.; Abreu, M. Manuela

    2017-04-01

    Repeated application of Copper (Cu) based fungicides in vineyards since the end of the 19th century has led to a significant increase in the concentration of this chemical element in many viticultural soils. Although Cu is an essential micronutrient for most organisms, it can be toxic for the development and survival of plants and soil (micro)organisms at high concentrations and eventually lead to yield loses in viticulture, as it negatively affects key physiological and biogeochemical processes. However, some soil microorganisms, including arbuscular mycorrhizal fungi (AMF), have developed adaptive mechanisms for persistence in environments with supra-optimal levels of essential elements or in the presence of harmful ones, as well as for increasing plant tolerance to such abiotic stress conditions. The objective of this work was to evaluate the effect of a high total soil concentration of Cu on microbial soil activity as well as on the development of mycorrhizal and non-mycorrhizal grapevines. A microcosm assay was set up under greenhouse and controlled conditions. Touriga Nacional grapevine variety plants grafted onto 1103P rootstocks were inoculated either with the AMF Rhizophagus irregularis or Funneliformis mosseae, or were left as non-inoculated controls. After three months, they were transplanted to containers filled with 4 kg of a sandy soil (pH: 7.0; electrical conductivity: 0.08 mS/cm; [organic C]: 5.6 g/kg; [N-NO3]: 1.1 mg/kg; [N-NH4]: 2.5 mg/kg; [extractable K]: 45.1 mg/kg; [extractable P]: 52.3 mg/kg), collected near to a vineyard in Pegões (Portugal). Two treatments were carried out: with and without Cu application. The soil with high Cu concentration was prepared by adding 300 mg Cu/kg (in the form of an aqueous solution of CuSO4·5H2O) followed by an incubation during four weeks in plastic bags at room temperature in dark. Physico-chemical soil characteristics (pH, electrical conductivity and nutrients concentration in available fraction), soil

  13. Response of Mycorrhizal Diversity to Current Climatic Changes

    OpenAIRE

    Williams, Stephen E.; Stanley E. Bellgard

    2011-01-01

    Form and function of mycorrhizas as well as tracing the presence of the mycorrhizal fungi through the geological time scale are herein first addressed. Then mycorrhizas and plant fitness, succession, mycorrhizas and ecosystem function, and mycorrhizal resiliency are introduced. From this, four hypotheses are drawn: (1) mycorrhizal diversity evolved in response to changes in Global Climate Change (GCC) environmental drivers, (2) mycorrhizal diversity will be modified by present changes in GCC ...

  14. Ecological specialization in mycorrhizal symbiosis leads to rarity in an endangered orchid.

    Science.gov (United States)

    Swarts, Nigel D; Sinclair, Elizabeth A; Francis, Anthony; Dixon, Kingsley W

    2010-08-01

    Terrestrial orchid germination, growth and development are closely linked to the establishment and maintenance of a relationship with a mycorrhizal fungus. Mycorrhizal dependency and specificity varies considerably between orchid taxa but the degree to which this underpins rarity in orchids is unknown. In the context of examining orchid rarity, large scale in vitro and in situ germination trials complemented by DNA sequencing were used to investigate ecological specialization in the mycorrhizal interaction of the rare terrestrial orchid Caladenia huegelii. Common and widespread sympatric orchid congeners were used for comparative purposes. Germination trials revealed an absolute requirement for mycorrhisation with compatibility barriers to germination limiting C. huegelii to a highly specific and range limited, efficacious mycorrhizal fungus. DNA sequencing confirmed fidelity between orchid and fungus across the distribution range of C. huegelii and at key life history stages within its life cycle. It was also revealed that common congeners could swap or share fungal partners including the fungus associated with the rare orchid but not vice versa. Data from this study provides evidence for orchid rarity as a cause and consequence of high mycorrhizal specialization. This interaction must be taken into account in efforts to mitigate the significant extinction risk for this species from anthropogenically induced habitat change and illustrates the importance of understanding fungal specificity in orchid ecology and conservation.

  15. EFFECT OF DIESEL AND BIODIESEL ON THE GROWTH OF Brachiaria decumbens INOCULATED WITH ARBUSCULAR MYCORRHIZAL FUNGI

    Directory of Open Access Journals (Sweden)

    Dora Trejo

    2013-12-01

    Full Text Available Arbuscular mycorrhizal fungi have been found to be associated with plants useful in soil phytoremediation. The aim of this study was to compare the effects of diesel and biodiesel in soil and sand on the growth of Brachiaria decumbens inoculated with mycorrhizae. Two experiments were carried out: one experiment in soil and another in sand. A two-level- factorial design with three factors was used (one on sterile and another on non-sterile soil, with and without mycorrhizae; and one with diesel and another with biodiesel. In sand, a two-factor design with two levels was used (with and without mycorrhizae and with diesel and biodiesel, both with three replications. NOVADIESEL, biodiesel and PEMEX diesel were use as contaminants, both at 7%. The fresh and dry weight of the plants and percentage of mycorrhizal colonization, were assessed 30 days after planting. In soil, biodiesel was more toxic and reduced the fresh and dry weights of plants, especially in non-sterile soil. Biodiesel yielded greater mycorrhizal colonization values that doubled those of the control. In sand, diesel was found to reduce three times the fresh and dry weights of plants, compared to the biodiesel. In sand diesel presented high values of mycorrhizal colonization in comparison with biodiesel.  Plants inoculated with mycorrhizal fungi exhibited better development than non-inoculated plants, even in the presence of contaminants.

  16. Plant and fungal gene expression in mycorrhizal protocorms of the orchid Serapias vomeracea colonized by Tulasnella calospora.

    Science.gov (United States)

    Balestrini, Raffaella; Nerva, Luca; Sillo, Fabiano; Girlanda, Mariangela; Perotto, Silvia

    2014-01-01

    Little is known on the molecular bases of plant-fungal interactions in orchid mycorrhiza. We developed a model system to investigate gene expression in mycorrhizal protocorms of Serapias vomeracea colonised by Tulasnella calospora. Our recent results with a small panel of genes as indicators of plant response to mycorrhizal colonization indicate that genes related with plant defense were not significantly up-regulated in mycorrhizal tissues. Here, we used laser microdissection to investigate whether expression of some orchid genes was restricted to specific cell types. Results showed that SvNod1, a S. vomeracea nodulin-like protein containing a plastocyanin-like domain, is expressed only in protocorm cells containing intracellular fungal hyphae. In addition, we investigated a family of fungal zinc metallopeptidases (M36). This gene family has expanded in the T. calospora genome and RNA-Seq experiments indicate that some members of the M36 metallopeptidases family are differentially regulated in orchid mycorrhizal protocorms.

  17. Diversity of arbuscular mycorrhizal fungi in Camellia sinensis in ...

    African Journals Online (AJOL)

    A study of diversity of arbuscular mycorrhizal fungi in Camellia sinensis was conducted in four plantation territories of Uttarakhand. Microscopic analysis of the mycorrhizal status of roots has revealed that samples from all four locations belonged only to AM fungi. The mycorrhizal colonization level was found high thus ...

  18. Plant and mycorrhizal weathering at the laboratory mesocosm scale

    Science.gov (United States)

    Andrews, M. Y.; Leake, J.; Banwart, S. A.; Beerling, D. J.

    2011-12-01

    The evolutionary development of large vascular land plants in the Paleozoic is hypothesized to have enhanced weathering of Ca and Mg silicate minerals. This plant-centric view overlooks the fact that plants and their associated mycorrhizal fungi co-evolved. Many weathering processes usually ascribed to plants may actually be driven by the combined activities of roots and mycorrhizal fungi. This study focuses on two key evolutionary events in plant and fungal evolution: 1) the transition from gymnosperm-only to mixed angiosperm-gymnosperm forests in the Mesozoic and 2) the similarly timed rise of ectomycorrhizal fungi (EM) in a previously arbuscular mycorrhizal (AM) only world. Here we present results from a novel mesocosm-scale laboratory experiment designed to allow investigation of plant- and mycorrhizae-driven carbon fluxes and mineral weathering at different soil depths, and under ambient (400 ppm) and elevated (1500 ppm) atmospheric CO2. To test our hypothesis that photosynthetic carbon flux from the plant to the roots and fungal partner drives biological weathering of minerals, we studied five mycorrhizal plant species: the gymnosperms Sequoia sempervirens (AM), Pinus sylvestris (EM) and Ginkgo biloba (AM), and two angiosperms, Magnolia grandiflora (AM) and Betula pendula (EM). This long term (7-9 months) experiment was grown in controlled environment chambers, with replicated systems at two atmospheric CO2 levels. Each mycorrhizal plant had access to isolated horizontal mesh cores containing crushed granite and basalt at three depths, in a compost:sand (50:50 vol:vol) bulk substrate, with appropriate plant-free and mineral-free controls. 14CO2 pulse-labeling provided a snapshot of the magnitude, timing, and allocation of carbon through the atmosphere-plant-fungi-soil system and also measured mycorrhizal fungal activity associated with the target granite and basalt. Total plant and fungal biomass were also assessed in relation to +/- mineral treatments and

  19. Arbuscular mycorrhizal colonization in soil fertilized by organic and mineral fertilizers

    Science.gov (United States)

    Dvořáčková, Helena; Záhora, Jaroslav; Mikajlo, Irina; Elbl, Jakub; Kynický, Jindřich; Hladký, Jan; Brtnický, Martin

    2017-04-01

    The level of arbuscular mycorrhizal colonization of roots represents one of the best parameters for assessing soil quality. This special type of symbiosis helps plants to obtain nutrients of the distant area which are unavailable without cooperation with arbuscular mycorrhizal fungi. For example the plant available form of phosphorus is of the most important elements in plant nutrition. This element can't move (significantly) throw the soil and it could be unachievable for root system of plant. The same situation also applies to other important nutrients and water. Colonization of individual roots by arbuscular mycorrhizal fungi has a direct effect on the enlargement of the root system but plant needs to invest sugar substance for development of fungi. It's very difficult to understand when fungi colonization represents indicator of good soil condition. And when it provides us with information "about plant stress". The main goal of our work was to compare the effect of different fertilizers application on development of arbuscular mycorrhizal colonization. We worked with organic fertilizers such as biochar from residual biomass, biochar from sewage sludge and ageing biochar and with mineral fertilizer DAM 390 (mixture of ammonium 25 %, nitrate 25 % and urea nitrogen 50 %). Effect of different types of the above fertilizers on development of arbuscular mycorrhizal colonization was tested by pot experiment with indicator plant Lactuca sativa L. The highest (P < 0.05) colonization of roots was found in variant with biochar from sewage sludge. The lower colonization was recognized in control variant and variant with addition of mineral fertilizer. Our results indicate positive effect of modified biochar application to soil on increase in level of arbuscular mycorrhizal colonization of roots.

  20. Auxin influences strigolactones in pea mycorrhizal symbiosis.

    Science.gov (United States)

    Foo, E

    2013-03-15

    Hormone interactions are essential for the control of many developmental processes, including intracellular symbioses. The interaction between auxin and the new plant hormone strigolactone in the regulation of arbuscular mycorrhizal symbiosis was examined in one of the few auxin deficient mutants available in a mycorrhizal species, the auxin-deficient bsh mutant of pea (Pisum sativum). Mycorrhizal colonisation with the fungus Glomus intraradices was significantly reduced in the low auxin bsh mutant. The bsh mutant also exhibited a reduction in strigolactone exudation and the expression of a key strigolactone biosynthesis gene (PsCCD8). Strigolactone exudation was also reduced in wild type plants when the auxin content was reduced by stem girdling. Low strigolactone levels appear to be at least partially responsible for the reduced colonisation of the bsh mutant, as application of the synthetic strigolactone GR24 could partially rescue the mycorrhizal phenotype of bsh mutants. Data presented here indicates root auxin content was correlated with strigolactone exudation in both mutant and wild type plants. Mutant studies suggest that auxin may regulate early events in the formation of arbuscular mycorrhizal symbiosis by controlling strigolactone levels, both in the rhizosphere and possibly during early root colonisation. Copyright © 2012 Elsevier GmbH. All rights reserved.

  1. The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Aerts, A.; Ahren, D.; Brun, A.; Danchin, E. G. J.; Duchaussoy, F.; Gibon, J.; Kohler, A.; Lindquist, E.; Peresa, V.; Salamov, A.; Shapiro, H. J.; Wuyts, J.; Blaudez, D.; Buee, M.; Brokstein, P.; Canback, B.; Cohen, D.; Courty, P. E.; Coutinho, P. M.; Delaruelle, C.; Detter, J. C.; Deveau, A.; DiFazio, S.; Duplessis, S.; Fraissinet-Tachet, L.; Lucic, E.; Frey-Klett, P.; Fourrey, C.; Feussner, I.; Gay, G.; Grimwood, J.; Hoegger, P. J.; Jain, P.; Kilaru, S.; Labbe, J.; Lin, Y. C.; Legue, V.; Le Tacon, F.; Marmeisse, R.; Melayah, D.; Montanini, B.; Muratet, M.; Nehls, U.; Niculita-Hirzel, H.; Secq, M. P. Oudot-Le; Peter, M.; Quesneville, H.; Rajashekar, B.; Reich, M.; Rouhier, N.; Schmutz, J.; Yin, T.; Chalot, M.; Henrissat, B.; Kues, U.; Lucas, S.; Van de Peer, Y.; Podila, G. K.; Polle, A.; Pukkila, P. J.; Richardson, P. M.; Rouze, P.; Sanders, I. R.; Stajich, J. E.; Tunlid, A.; Tuskan, G.; Grigoriev, I. V.

    2007-08-10

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants 1, 2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are

  2. Metabolic transition in mycorrhizal tomato roots

    Science.gov (United States)

    Rivero, Javier; Gamir, Jordi; Aroca, Ricardo; Pozo, María J.; Flors, Víctor

    2015-01-01

    Beneficial plant–microorganism interactions are widespread in nature. Among them, the symbiosis between plant roots and arbuscular mycorrhizal fungi (AMF) is of major importance, commonly improving host nutrition and tolerance against environmental and biotic challenges. Metabolic changes were observed in a well-established symbiosis between tomato and two common AMF: Rhizophagus irregularis and Funneliformis mosseae. Principal component analysis of metabolites, determined by non-targeted liquid chromatography–mass spectrometry, showed a strong metabolic rearrangement in mycorrhizal roots. There was generally a negative impact of mycorrhizal symbiosis on amino acid content, mainly on those involved in the biosynthesis of phenylpropanoids. On the other hand, many intermediaries in amino acid and sugar metabolism and the oxylipin pathway were among the compounds accumulating more in mycorrhizal roots. The metabolic reprogramming also affected other pathways in the secondary metabolism, mainly phenyl alcohols (lignins and lignans) and vitamins. The results showed that source metabolites of these pathways decreased in mycorrhizal roots, whilst the products derived from α-linolenic and amino acids presented higher concentrations in AMF-colonized roots. Mycorrhization therefore increased the flux into those pathways. Venn-diagram analysis showed that there are many induced signals shared by both mycorrhizal interactions, pointing to general mycorrhiza-associated changes in the tomato metabolome. Moreover, fungus-specific fingerprints were also found, suggesting that specific molecular alterations may underlie the reported functional diversity of the symbiosis. Since most positively regulated pathways were related to stress response mechanisms, their potential contribution to improved host stress tolerance is discussed. PMID:26157423

  3. Widespread mycorrhizal specificity correlates to mycorrhizal function in the neotropical, epiphytic orchid Ionopsis utricularioides (Orchidaceae).

    Science.gov (United States)

    Otero, J Tupac; Flanagan, Nicola S; Herre, E Allen; Ackerman, James D; Bayman, Paul

    2007-12-01

    Tropical orchids constitute the greater part of orchid diversity, but little is known about their obligate mycorrhizal relationships. The specificity of these interactions and associated fungal distributions could influence orchid distributions and diversity. We investigated the mycorrhizal specificity of the tropical epiphytic orchid Ionopsis utricularioides across an extensive geographical range. DNA ITS sequence variation was surveyed in both plants and mycorrhizal fungi. Phylogeographic relationships were estimated for the mycorrhizal fungi. Orchid functional outcomes were determined through in vitro seed germination and seedling growth with a broad phylogenetic representation of fungi. Most fungal isolates derived from one clade of Ceratobasidium (anamorphs assignable to Ceratorhiza), with 78% within a narrower phylogenetic group, clade B. No correlation was found between the distributions of orchid and fungal genotypes. All fungal isolates significantly enhanced seed germination, while fungi in clade B significantly enhanced seedling growth. These results show that I. utricularioides associates with a phylogenetically narrow, effective fungal clade over a broad distribution. This preference for a widespread mycorrhizae may partly explain the ample distribution and abundance of I. utricularioides and contrasts with local mycorrhizal diversification seen in some nonphotosynthetic orchids. Enhanced orchid function with a particular fungal subclade suggests mycorrhizal specificity can increase orchid fitness.

  4. Desenvolvimento Vegetativo e morfologia radicular de citrange carrizo afetado por ácido indolbutírico e micorrizas arbusculares Vegetative development and root morphology of carrizo citrange affected by indolebutyric acid and arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Paulo Vitor Dutra de Souza

    2000-04-01

    Full Text Available Este estudo foi realizado na localidade de Alcanar (Tarragona, Espanha e objetivou avaliar o efeito de cinco concentrações do ácido indolbutírico (AIB (0,0; 0,5; 1,0; 1,5; 2,0 g/L e da inoculação com micorrizas arbusculares (MA (Glomus intraradices Schenck & Smith sobre o desenvolvimento vegetativo, conteúdo foliar de P e K e morfologia radicular de plântulas de citrange Carrizo (Citrus sinensis (L. X Poncirus trifoliata (L. Raf.. Utilizou-se o delineamento experimental de blocos completos casualisados em esquema fatorial, com 4 repetições e 10 plantas por parcela. A aplicação de AIB não alterou o desenvolvimento vegetativo das plântulas cultivadas em ausência de MA, apesar de haver incrementado a quantidade de P e K e a espessura dos feixes vasculares. As MA incrementaram o conteúdo de P foliar. Encontrou-se uma interação positiva entre o AIB e as MA, pois as plântulas micorrizadas apresentaram um incremento no desenvolvimento vegetativo, nos conteúdos foliares de P e K e na espessura dos feixes vasculares com o aumento das concentrações de AIB.This study was carried out in Alcanar (Tarragona - Spain to evaluate the effect of five indolebutyric acid (IBA concentrations (0.0; 0.5; 1.0; 1.5; 2.0 g/L and inoculation with arbuscular mycorrhizae fungi (AMF (Glomus intraradices Schenck & Smith on Carrizo citrange (Citrus sinensis (L. x Poncirus trifoliata (L. Raf. vegetative development, P and K foliar contents and root morphology. The experimental design was in a Completly Randomized Block Design with 10 seedlings per plot and 4 replicates. The IBA concentrations had no effect on vegetative development of nonmycorrhizal seedlings, althougt it had increased P and K foliar contents and primary xylem tickness. AMF increased P foliar content. IBA x AMF interaction was observed, increasing IBA concentrations on mycorrhizal seedlings resulted in increased in vegetative development, P and K foliar contents and primary xylem thickness.

  5. Mycorrhizal symbiosis enhances Phalaenopsis orchid's growth and ...

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... mycorrhizal associations: Comparisons with the Rhizobium-legume symbiosis. Fungal Genet. Biol. 23: 205-212. Johnson TR, Stewart SL, Dytra D, Kane ME, and Richardson L (2007). Asymbiotic and symbiotic seed germination of Eulophia alta. (Orchidaceae)-preliminary evidence for the symbiotic culture.

  6. Response of Arbuscular mycorrhizal fungi and Rhizobium ...

    African Journals Online (AJOL)

    Michael Horsfall

    the alternative sources to meet the nutrient requirement of crops. Arbuscular Mycorrhizal (AM) fungi are found in many soils around the w orld, and they form association with 80% of all terrestrial plant roots (Harley and Harley, 1987). The beneficial effects of AM fungi symbiotic association on the growth of plants are well ...

  7. Response of Arbuscular mycorrhizal fungi and Rhizobium ...

    African Journals Online (AJOL)

    The aim of the present study was to investigate the effect ofRhizobium and Arbuscular mycorrhizal fungi inoculation, both individually and in combination on growth and chlorophyll content of economically important plant Vigna unguiculata L. A significant (p < 0.05) increase over control in root length (45.6 cm), shoot height ...

  8. Interaction of arbuscular mycorrhizal fungus ( Glomus intraradices ...

    African Journals Online (AJOL)

    In this research, the effect of two arbuscular mycorrhizal fungal (AMF) inoculation (Glomus intraradices and Glomus etunicatum) on tomato plants growing in nutrient solution with high concentrations of copper were studied. Copper (Cu) is an essential micronutrient for plant growth. In the present study, the effect of copper ...

  9. Composition of arbuscular mycorrhizal fungi associated with ...

    African Journals Online (AJOL)

    Composition of arbuscular mycorrhizal fungi associated with cassava (Manihot esculenta Crantz) cultivars as influenced by chemical fertilization and tillage in Cameroon. Didier Aime Boyogueno Begoude, Papa Saliou Sarr, Tatiana Laure Yondi Mpon, Didier Alexis Owona, Miraine Ndacnou Kapeua, Shigeru Araki ...

  10. Production of native arbuscular mycorrhizal fungi inoculum under different environmental conditions

    Directory of Open Access Journals (Sweden)

    Yamir Torres-Arias

    Full Text Available Abstract In order to obtain an arbuscular mycorrhizal fungi (AMF native inoculum from Sierra de Moa and determine the most appropriate conditions for its big scale production, four light and temperature combinations were tested in three plant species (Calophyllum antillanum, Talipariti elatum and Paspalum notatum. Growth and development parameters, as well as the mycorrhizal functioning of the seedlings were evaluated. The natural light treatment under high temperatures (L-H was the most suitable for the growth and development of the three plant species, showing the highest total biomass values, mainly of root, and a positive root-shoot ratio balance. This treatment also promoted higher values of root mycorrhizal colonization, external mycelium and AMF spore density. A total of 38 AMF species were identified among the plants and environmental conditions tested. Archaeospora sp.1, Glomus sp.5, Glomus brohultii and G. glomerulatum were observed in all the treatments. The L-H condition can be recommended for native inoculum production, as it promotes a better expression of the AM symbiosis and an elevated production of mycorrhizal propagules.

  11. 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.

  12. The Physiological Response of Soybean Genotypes to VAM Inoculation on Selected Drought Stress Levels

    Directory of Open Access Journals (Sweden)

    HAPSOH

    2006-06-01

    Full Text Available Present research was aimed to study physiological changes of soybean which were inoculated with vesicular arbuscular mycorrhizal fungi (VAM. Glomus etunicatum was exposed to moderate and severe drought condition. Symbiotic association with VAM improved adaptability as it was shown by the increasing leaf proline content. The MLG 3474 and Sindoro are the more tolerant genotypes while the responses of plant to VAM on improving the adaptability to drought were larger on Lokon.

  13. From root to fruit: RNA-Seq analysis shows that arbuscular mycorrhizal symbiosis may affect tomato fruit metabolism.

    Science.gov (United States)

    Zouari, Inès; Salvioli, Alessandra; Chialva, Matteo; Novero, Mara; Miozzi, Laura; Tenore, Gian Carlo; Bagnaresi, Paolo; Bonfante, Paola

    2014-03-21

    Tomato (Solanum lycopersicum) establishes a beneficial symbiosis with arbuscular mycorrhizal (AM) fungi. The formation of the mycorrhizal association in the roots leads to plant-wide modulation of gene expression. To understand the systemic effect of the fungal symbiosis on the tomato fruit, we used RNA-Seq to perform global transcriptome profiling on Moneymaker tomato fruits at the turning ripening stage. Fruits were collected at 55 days after flowering, from plants colonized with Funneliformis mosseae and from control plants, which were fertilized to avoid responses related to nutrient deficiency. Transcriptome analysis identified 712 genes that are differentially expressed in fruits from mycorrhizal and control plants. Gene Ontology (GO) enrichment analysis of these genes showed 81 overrepresented functional GO classes. Up-regulated GO classes include photosynthesis, stress response, transport, amino acid synthesis and carbohydrate metabolism functions, suggesting a general impact of fungal symbiosis on primary metabolisms and, particularly, on mineral nutrition. Down-regulated GO classes include cell wall, metabolism and ethylene response pathways. Quantitative RT-PCR validated the RNA-Seq results for 12 genes out of 14 when tested at three fruit ripening stages, mature green, breaker and turning. Quantification of fruit nutraceutical and mineral contents produced values consistent with the expression changes observed by RNA-Seq analysis. This RNA-Seq profiling produced a novel data set that explores the intersection of mycorrhization and fruit development. We found that the fruits of mycorrhizal plants show two transcriptomic "signatures": genes characteristic of a climacteric fleshy fruit, and genes characteristic of mycorrhizal status, like phosphate and sulphate transporters. Moreover, mycorrhizal plants under low nutrient conditions produce fruits with a nutrient content similar to those from non-mycorrhizal plants under high nutrient conditions

  14. Mycorrhizal compatibility and symbiotic reproduction of Gavilea australis, an endangered terrestrial orchid from south Patagonia.

    Science.gov (United States)

    Fracchia, Sebastián; Aranda-Rickert, Adriana; Flachsland, Eduardo; Terada, Graciela; Sede, Silvana

    2014-11-01

    Gavilea australis is a terrestrial orchid endemic from insular south Argentina and Chile. Meeting aspects of mycorrhizal fungi identity and compatibility in this orchid species is essential for propagation and conservation purposes. These knowledge represent also a first approach to elucidate the mycorrhizal specificity of this species. In order to evaluate both the mycorrhizal compatibility and the symbiotic seed germination of G. australis, we isolated and identified its root endophytic fungal strains as well as those from two sympatric species: Gavilea lutea and Codonorchis lessonii. In addition, we tested two other strains isolated from allopatric terrestrial orchid species from central Argentina. All fungal strains formed coilings and pelotons inside protocorms and promoted, at varying degrees, seed germination, and protocorm development until seedlings had two to three leaves. These results suggest a low mycorrhizal specificity of G. australis and contribute to a better knowledge of the biology of this orchid as well as of other sympatric Patagonian orchid species, all of them currently under serious risk of extinction.

  15. Mycorrhizal fungi increase coffee plants competitiveness against Bidens pilosa interference

    Directory of Open Access Journals (Sweden)

    André Cabral França

    2016-06-01

    Full Text Available Mycorrhizae provide several benefits to coffee plants. This study evaluated whether these benefits influence the damage caused by the Bidens pilosa competition with coffee seedlings. A randomized blocks design was used, with treatments established in a 2 x 3 factorial scheme (presence and absence of B. pilosa interference in non-inoculated control or plants inoculated with either Claroideoglomus etunicatum or Dentiscutata heterogama. Coffee seedlings were inoculated with fungi spores and developed for 120 days. Then, they were subjected to the interference of B. pilosa for more 120 days, when data were collected for growth traits, mycorrhizal colonization, dry matter and foliar nutrient concentrations in coffee plants. Dry matter and nutrient contents in B. pilosa plants were also evaluated. Inoculation provided better growth and nutrition of coffee plants. The competition with B. pilosa reduced mycorrhizal colonization, height, leaf area, leaf and stem dry mass, root dry weight, number of reproductive branches and levels of P and Fe in the coffee plants. However, the harmful effect of the interference was lower in inoculated coffee plants. The dry mass of B. pilosa decreased under the interference of inoculated coffee plants. The inoculation of C. etunicatum and D. heterogama in Arabica coffee seedlings increases the competitiveness of the crop against B. pilosa interference.

  16. Experimental evidence of ericoid mycorrhizal potential within Serendipitaceae (Sebacinales).

    Science.gov (United States)

    Vohník, Martin; Pánek, Matěj; Fehrer, Judith; Selosse, Marc-André

    2016-11-01

    The Sebacinales are a monophyletic group of ubiquitous hymenomycetous mycobionts which form ericoid and orchid mycorrhizae, ecto- and ectendomycorrhizae, and nonspecific root endophytic associations with a wide spectrum of plants. However, due to the complete lack of fungal isolates derived from Ericaceae roots, the Sebacinales ericoid mycorrhizal (ErM) potential has not yet been tested experimentally. Here, we report for the first time isolation of a serendipitoid (formerly Sebacinales Group B) mycobiont from Ericaceae which survived in pure culture for several years. This allowed us to test its ability to form ericoid mycorrhizae with an Ericaceae host in vitro, to describe its development and colonization pattern in host roots over time, and to compare its performance with typical ErM fungi and other serendipitoids derived from non-Ericaceae hosts. Out of ten serendipitoid isolates tested, eight intracellularly colonized Vaccinium hair roots, but only the Ericaceae-derived isolate repeatedly formed typical ericoid mycorrhiza morphologically identical to ericoid mycorrhiza commonly found in naturally colonized Ericaceae, but yet different from ericoid mycorrhiza formed in vitro by the prominent ascomycetous ErM fungus Rhizoscyphus ericae. One Orchidaceae-derived isolate repeatedly formed abundant hyaline intracellular microsclerotia morphologically identical to those occasionally found in naturally colonized Ericaceae, and an isolate of Serendipita (= Piriformospora) indica produced abundant intracellular chlamydospores typical of this species. Our results confirm for the first time experimentally that some Sebacinales can form ericoid mycorrhiza, point to their broad endophytic potential in Ericaceae hosts, and suggest possible ericoid mycorrhizal specificity in Serendipitaceae.

  17. Plant Functional Traits Associated with Mycorrhizal Root Foraging in Arbuscular Mycorrhizal and Ectomycorrhizal Trees

    Science.gov (United States)

    Eissenstat, D. M.; Chen, W.; Cheng, L.; Liu, B.; Koide, R. T.; Guo, D.

    2016-12-01

    Root foraging for nutrient "hot spots" is a key strategy by which some plants maximize nutrient gain from their carbon investment in root and mycorrhizal hyphae. Foraging strategies may depend on costs of root construction, with thick roots generally costing more per unit length than thin roots. Investment in mycorrhizal hyphae, which are considerably thinner than roots, may represent an alternative strategy for cost-effective nutrient foraging, especially for thick-root species. Type of mycorrhiza may matter, as ectomycorrhizal (EM) fungi are more associated with longer hyphae and ability to mineralize organic matter than arbuscular mycorrhizal (AM) fungi. Among AM trees in both subtropical forests in SE China and in temperate forests in central Pennsylvania, USA, we found that tree species with thin roots proliferated their roots in soil patches enriched with mineral nutrients to a greater extent than species with thick roots. In addition, thick-root species were consistently colonized more heavily with mycorrhizal fungi than thin root species, although nutrient addition tended to diminish colonization. In a common garden in central Pennsylvania of both AM and EM tree species, we found that nutrient patches enriched with organic materials resulted in greater root and mycorrhizal fungal proliferation compared to those enriched with inorganic nutrients and that thick-root species proliferated more with their mycorrhizal fungi whereas thin-root species proliferated more with their roots. We further examined with many more species, patterns of root and mycorrhizal fungal proliferation in organic-nutrient-enriched patches. Foraging precision, or the extent that roots or mycorrhizal hyphae grew in the enriched patch relative to the unenriched patch, was related to both root thickness and type of mycorrhiza. In both AM and EM trees, thick-root species were not selective foragers of either their roots or hyphae. In thin-root species, there was strong selectivity in

  18. Influence of nitrogen and phosphorus sources on mycorrhizal lettuces under organic farming

    Science.gov (United States)

    Scotti, Riccardo; Seguel, Alex; Cornejo, Pablo; Rao, Maria A.; Borie, Fernando

    2010-05-01

    Arbuscular mycorrhizal fungi (AMF) develop symbiotic associations with plants roots. These associations are very common in the natural environment and can provide a range of benefits to the host plant. AMF improve nutrition, enhance resistance to soil-borne pests and disease, increase resistance to drought and tolerance to heavy metals, and contribute to a better soil structure. However, agricultural intensive managements, such as the use of mineral fertilizes, pesticides, mouldboard tillage, monocultures and use of non-mycorrhizal crops, are detrimental to AMF. As a consequence, agroecosystems are impoverished in AMF and may not provide the full range of benefits to the crop. Organic farming systems may be less unfavourable to AMF because they exclude the use of water-soluble fertilisers and most pesticides, and generally they plan diverse crop rotations. The AMF develop the most common type of symbiosis in nature: about 90% of the plants are mycorrhizal and many agricultural crops are mycorrhizal. One of more mycorrhizal crops is lettuce, that is very widespread in intensive agricultural under greenhouse. Therefore, cultivated lettuce is know to be responsive to mycorrhizal colonization which can reach 80% of root length and contribute to phosphorus and nitrogen absorption by this plant specie. For this work four different lettuce cultivars (Romana, Milanesa, Grande Lagos and Escarola) were used to study mycorrhization under organic agricultural system, supplying compost from agricultural waste (1 kg m-2) as background fertilization for all plots, red guano as phosphorus source (75 U ha-1 and 150 U ha-1 of P2O5), lupine flour as nitrogen source (75 and 150 U/ha of N) and a combination of both. Lettuce plants were cultivated under greenhouse and after two months of growing, plants were harvested and dried and fresh weight of lettuce roots and shoots were evaluated. The number of spores, percentage of colonization, total mycelium and glomalin content were also

  19. Dioecious species and arbuscular mycorrhizal symbioses

    Science.gov (United States)

    Vega-Frutis, Rocío; Varga, Sandra; Kytöviita, Minna-Maarit

    2013-01-01

    Sex-specific interactions with herbivores and pollinators have been observed in female and male plants of dioecious species. However, only a limited number of studies have revised sex-specific patterns in mycorrhizal symbiosis. To test whether female and male plants of Antennaria dioica differ in their relationship with arbuscular mycorrhizal (AM) fungi, we examined the temporal and spatial variation in AM fungi in female, male and non-reproductive A. dioica plants in three natural populations in Finland during flowering and after seed production. Our results are consistent with previous studies both under greenhouse and field conditions with the same species showing differences in AM colonization between the sexes linked with allocation to reproduction. Taken together, the results indicate that there is a sex-specific interaction between A. dioica and AM fungi. Overall, females have a greater investment in AM fungi, likely to enhance their uptake of soil nutrients and support the reproduction by seed. PMID:23299337

  20. Phosphatase activity in sandy soil influenced by mycorrhizal and non-mycorrhizal cover crops

    Directory of Open Access Journals (Sweden)

    Alceu Kunze

    2011-06-01

    Full Text Available Cover crops may difffer in the way they affect rhizosphere microbiota nutrient dynamics. The purpose of this study was to evaluate the effect of mycorrhizal and non-mycorrhizal cover crops on soil phosphatase activity and its persistence in subsequent crops. A three-year experiment was carried out with a Typic Quartzipsamment. Treatments were winter species, either mycorrhizal black oat (Avena strigosa Schreb or the non-mycorrhizal species oilseed radish (Raphanus sativus L. var. oleiferus Metzg and corn spurry (Spergula arvensis L.. The control treatment consisted of resident vegetation (fallow in the winter season. In the summer, a mixture of pearl millet (Pennisetum americanum L. with sunnhemp (Crotalaria juncea L. or with soybean (Glycine max L. was sown in all plots. Soil cores (0-10 cm and root samples were collected in six growing seasons (winter and summer of each year. Microbial biomass P was determined by the fumigation-extraction method and phosphatase activity using p-nitrophenyl-phosphate as enzyme substrate. During the flowering stage of the winter cover crops, acid phosphatase activity was 30-35 % higher in soils with the non-mycorrhizal species oilseed radish, than in the control plots, regardless of the amount of P immobilized in microbial biomass. The values of enzyme activity were intermediate in the plots with corn spurry and black oat. Alkaline phosphatase activity was 10-fold lower and less sensitive to the treatments, despite the significant relationship between the two phosphatase activities. The effect of plant species on the soil enzyme profile continued in the subsequent periods, during the growth of mycorrhizal summer crops, after completion of the life cycle of the cover crops.

  1. Effect of arbuscular mycorrhizal and bacterial inocula on nitrate concentration in mesocosms simulating a wastewater treatment system relying on phytodepuration.

    Science.gov (United States)

    Lingua, Guido; Copetta, Andrea; Musso, Davide; Aimo, Stefania; Ranzenigo, Angelo; Buico, Alessandra; Gianotti, Valentina; Osella, Domenico; Berta, Graziella

    2015-12-01

    High nitrogen concentration in wastewaters requires treatments to prevent the risks of eutrophication in rivers, lakes and coastal waters. The use of constructed wetlands is one of the possible approaches to lower nitrate concentration in wastewaters. Beyond supporting the growth of the bacteria operating denitrification, plants can directly take up nitrogen. Since plant roots interact with a number of soil microorganisms, in the present work we report the monitoring of nitrate concentration in macrocosms with four different levels of added nitrate (0, 30, 60 and 90 mg l(-1)), using Phragmites australis, inoculated with bacteria or arbuscular mycorrhizal fungi, to assess whether the use of such inocula could improve wastewater denitrification. Higher potassium nitrate concentration increased plant growth and inoculation with arbuscular mycorrhizal fungi or bacteria resulted in larger plants with more developed root systems. In the case of plants inoculated with arbuscular mycorrhizal fungi, a faster decrease of nitrate concentration was observed, while the N%/C% ratio of the plants of the different treatments remained similar. At 90 mg l(-1) of added nitrate, only mycorrhizal plants were able to decrease nitrate concentration to the limits prescribed by the Italian law. These data suggest that mycorrhizal and microbial inoculation can be an additional tool to improve the efficiency of denitrification in the treatment of wastewaters via constructed wetlands.

  2. Plant mycorrhizal traits and carbon fates from plot to globe

    Science.gov (United States)

    Soudzilovskaia, N.; Cornelissen, H. H. C.

    2016-12-01

    Evidence is accumulating that plant traits related to mycorrhizal symbiosis, i.e. mycorrhizal type and the degree of plant root colonization by mycorrhizal fungi have important consequences for carbon pools and allocation in plants and soil. How plant and soil carbon pools vary among vegetation dominated by plants of different mycorrhizal types is a new and exciting research challenge. Absence of global databases on abundance of mycorrhizal fungi in soil and plant roots retards research aimed to understand involvement of mycorrhizas into soil carbon transformation processes. Using own data and published studies we have assembled currently world-largest database of plant species-per-site degrees root colonization by two most common types of mycorrhizal fungi, arbuscular mycorrhizal (AM) and ectomycorrhizal (EM). The database features records for plant root colonization degrees by AM and EM (above 8000 records in total). Using this database, we demonstrate that the degree of mycorrhizal fungal colonization has globally consistent patterns across plant species. This suggests that the level of plant species-specific root colonization can be used as a plant trait. I will discuss how combining plot-level field data, literature data and mycorrhizal infection trait data may help us to quantify the carbon consequences of relative dominance by arbuscular versus ectomycorrhizal symbiosis in vegetation from plot to global scale. To exemplify this method, I will present an assessment of the impacts of EM shrub encroachment on carbon stocks in sub-arctic tundra, and show how the plant trait data (root, leaf, stem and mycorrhizal colonization traits) could predict (1) impacts of AM and EM vegetation on soil carbon budget and (2) changes in soil carbon budget due to increase of EM plants in an AM-dominated ecosystem and visa versa. This approach may help to predict how global change-mediated vegetation shifts, via mycorrhizal carbon pools and dynamics, may affect terrestric and

  3. Mycorrhizal diversity and specificity in Lecanorchis (Orchidaceae).

    Science.gov (United States)

    Okayama, Masanari; Yamato, Masahide; Yagame, Takahiro; Iwase, Koji

    2012-10-01

    Lecanorchis is a nonphotosynthetic plant genus in Vanilloideae, Orchidaceae. Because of the distribution of many Lecanorchis taxa in various climate conditions, we hypothesized that mycorrhizal diversity and specificity are different among the different taxa of Lecanorchis. In the present study, identities of mycorrhizal fungi were examined for 90 individuals of 10 Lecanorchis taxa at 26 sites from Niigata to Okinawa Prefectures in Japan. Phylogenetic analyses of Lecanorchis taxa based on the internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene (rDNA) divided the examined Lecanorchis taxa into three groups, groups A, B, and C. ITS rDNA sequences suggested that fungi associating with Lecanorchis were ectomycorrhiza-forming fungi in Lactarius, Russula, Atheliaceae, and Sebacina, with Lactarius and Russula dominant. Our results suggested some degree of mycorrhizal specialization among Lecanorchis taxa. Interestingly, the Lecanorchis group C had some specific relationships with Lactarius, whereas less specificity was found in the relationships with Russula. However, observed specificity results may be biased by geographic opportunity, and we suggest further research to assess whether Lecanorchis species are limited to the associations we observed.

  4. Inoculation of Ceratonia siliqua L. with native arbuscular mycorrhizal ...

    African Journals Online (AJOL)

    Ouhmane

    In Morocco, the production of carob was estimated only to 8% of the world production. This production considered .... mycorrhizal maize roots were used for the control treatment. Mycorrhizal inoculation of C. siliqua seedlings and plant .... Hence the selection of efficient AM fungi is a key factor to ensure the success of soil.

  5. Does mycorrhizal specificity affect orchid decline and rarity?

    Science.gov (United States)

    Bailarote, Bruno Cachapa; Lievens, Bart; Jacquemyn, Hans

    2012-10-01

    Orchids rely on mycorrhizal fungi for seed germination, and many species maintain associations during later stages in their life cycle. Because of the critical dependence of orchids on fungi it has been suggested that the degree of mycorrhizal specificity may be associated with rarity and long-term survival of orchid species, especially in highly degraded or fragmented landscapes. To test this hypothesis, we compared mycorrhizal communities in two species that differed significantly in decline in Belgium and other parts of Europe. • Mycorrhizal associations were investigated in five populations of Anacamptis morio and Dactylorhiza fuchsii in Belgium. ITS-based DNA arrays were used for simultaneous detection and identification of a wide range of basidiomycetous mycorrhizal fungi. Mycorrhizal specificity, measured as phylogenetic diversity, was assessed for each population and compared between species. • For both species, the degree of phylogenetic relatedness of the mycorrhizal partners was low, and both species were associated with a large number of fungal lineages related to clades of the Tulasnellaceae family. Contrary to expectations, the species that was apparently resilient to decline was associated with fewer fungal operational taxonomical units than the declining species was, and the phylogenetic relatedness of mycorrhizal communities among populations was higher in the stable than in the declining orchid. • Although our results do not present detailed insights into the causes of orchid persistence, they do suggest that orchid rarity and persistence are not necessarily related to fungal diversity and that other factors may be more important in determining orchid persistence.

  6. Dominant forest tree mycorrhizal type mediates understory plant invasions

    Science.gov (United States)

    Insu Jo; Kevin M. Potter; Grant M. Domke; Songlin Fei

    2017-01-01

    Forest mycorrhizal type mediates nutrient dynamics, which in turn can influence forest community structure and processes. Using forest inventory data, we explored how dominant forest tree myc- orrhizal type affects understory plant invasions with consideration of forest structure and soil properties. We found that arbuscular mycorrhizal (AM) dominant forests, which are...

  7. Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Coffea ...

    African Journals Online (AJOL)

    Objective: This study describes the status of mycorrhizal fungi in coffee (Coffea arabica) in the Yemeni ecosystems. Methodology and results: Soil samples were extracted from the rhizosphere of the coffee tree groves in several regions of Yemen. The frequency and the level of colonization of the arbuscular mycorrhizal fungi ...

  8. Effects of arbuscular mycorrhizal fungi on resistance to Phytophthora ...

    African Journals Online (AJOL)

    xp

    2012-06-28

    Jun 28, 2012 ... mycorrhizal (AM) fungi and Phytophthora parasitica of different citrus genotypes and the effect of AM fungi on the growth of ... Key words: Phytophthora parasitica, citrus, rootstock, arbuscular mycorrhizal (AM) fungi, root rot. INTRODUCTION ... It belongs in the kingdom Stramenopila, phylum Oomycota, and ...

  9. Colonization of new land by arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Nielsen, Knud Nor; Kjøller, Rasmus; Bruun, Hans Henrik

    2016-01-01

    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 wa...

  10. Mycorrhizal association of some agroforestry tree species in two ...

    African Journals Online (AJOL)

    Mycorrhizal colonization of different agroforestry tree species in two social forestry nurseries was investigated. Percentage of Arbuscular mycorrhizal (AM) infection, number of resting spores and AM fungi species varies both in tree species as well as in two different nurseries. This variation is attributed to various factors such ...

  11. Effect of arbuscular mycorrhizal fungal inoculation on growth, and ...

    African Journals Online (AJOL)

    Effect of arbuscular mycorrhizal fungal inoculation on growth, and nutrient uptake of the two grass species, Leptochloa fusca (L.) Stapf and Sporobolus robustus ... MD and shoot mineral contents (especially P) varied with AMF host plants. ... Key words: Grass species, symbiosis, mycorrhizal dependency, mineral nutrition.

  12. Mycorrhizal status of Lycium europaeum in the coastal dunes of ...

    African Journals Online (AJOL)

    Objective: This study describes the mycorrhizal status of Lycium europaeum in the mobile and fixed dunes in the coastal area of Mehdia (Northwest of Morocco). Methodology and results: Evaluation of the mycorrhization level in the roots was effected and the identification of the arbuscular mycorrhizal fungi was based on ...

  13. Contribution of arbuscular mycorrhizal fungus to red kidney and ...

    African Journals Online (AJOL)

    The researcher had investigated the role of arbuscular mycorrhizal fungal inoculation in red idney and wheat in heavy metals tolerance in soil artificially contaminated with high oncentrations of zinc, copper, lead and cadmium. Metals accumulated by mycorrhizal wheat lants were mostly distributed in root tissues, suggesting ...

  14. Molecular characterisation of a mycorrhizal inoculant that enhances ...

    African Journals Online (AJOL)

    The occurrence of drought is an economically important problem in Morocco. The use of mycorrhizal technology offers a possibility to overcome this problem. A mycorrhizal fungal inoculum “Aoufous Complex” isolated in Morocco was shown to enhance Trifolium alexandrium resistance in water deficit situation.

  15. Mycorrhizal status of Olea europaea spp. oleaster in Morocco | Sghir ...

    African Journals Online (AJOL)

    Objective: This study describes the mycorrhizal oleaster status (Olea europaea ssp. oleaster:) in the Moroccan ecosystems. Methodology and results: Soil samples were extracted from the rhizosphere of the oleaster tree groves in several regions of Morocco. The frequency and the levels of the arbuscular mycorrhizal fungi ...

  16. Dominant forest tree mycorrhizal type mediates understory plant invasions.

    Science.gov (United States)

    Jo, Insu; Potter, Kevin M; Domke, Grant M; Fei, Songlin

    2018-02-01

    Forest mycorrhizal type mediates nutrient dynamics, which in turn can influence forest community structure and processes. Using forest inventory data, we explored how dominant forest tree mycorrhizal type affects understory plant invasions with consideration of forest structure and soil properties. We found that arbuscular mycorrhizal (AM) dominant forests, which are characterised by thin forest floors and low soil C : N ratio, were invaded to a greater extent by non-native invasive species than ectomycorrhizal (ECM) dominant forests. Understory native species cover and richness had no strong associations with AM tree dominance. We also found no difference in the mycorrhizal type composition of understory invaders between AM and ECM dominant forests. Our results indicate that dominant forest tree mycorrhizal type is closely linked with understory invasions. The increased invader abundance in AM dominant forests can further facilitate nutrient cycling, leading to the alteration of ecosystem structure and functions. © 2017 John Wiley & Sons Ltd/CNRS.

  17. Differential access to phosphorus pools of an Oxisol by mycorrhizal and non-mycorrhizal maize

    NARCIS (Netherlands)

    Cardoso, I.M.; Boddington, C.L.; Janssen, B.H.; Oenema, O.; Kuyper, T.W.

    2006-01-01

    This study investigated whether arbuscular mycorrhizal fungi (AMF) could take up phosphorus (P) from pools that are normally considered unavailable to plants. An aluminum (Al) resistant maize variety, inoculated with three species of Glomus or uninoculated, supplied with nutrient solution without P,

  18. Maintenance and preservation of ectomycorrhizal and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Lalaymia, Ismahen; Cranenbrouck, Sylvie; Declerck, Stéphane

    2014-07-01

    Short- to long-term preservation of mycorrhizal fungi is essential for their in-depth study and, in the case of culture collections, for safeguarding their biodiversity. Many different maintenance/preservation methods have been developed in the last decades, from soil- and substrate-based maintenance to preservation methods that reduce (e.g., storage under water) or arrest (e.g., cryopreservation) growth and metabolism; all have advantages and disadvantages. In this review, the principal methods developed so far for ectomycorrhizal and arbuscular mycorrhizal fungi are reported and described given their distinct biology/ecology/evolutionary history. Factors that are the most important for their storage are presented and a protocol proposed which is applicable, although not generalizable, for the long-term preservation at ultra-low temperature of a large panel of these organisms. For ECM fungi, isolates should be grown on membranes or directly in cryovials until the late stationary growth phase. The recommended cryopreservation conditions are: a cryoprotectant of 10% glycerol, applied 1-2 h prior to cryopreservation, a slow cooling rate (1 °C min(-1)) until storage below -130 °C, and fast thawing by direct plunging in a water bath at 35-37 °C. For AMF, propagules (i.e., spores/colonized root pieces) isolated from cultures in the late or stationary phase of growth should be used and incorporated in a carrier (i.e., soil or alginate beads), preferably dried, before cryopreservation. For in vitro-cultured isolates, 0.5 M trehalose should be used as cryoprotectant, while isolates produced in vivo can be preserved in dried soil without cryoprotectant. A fast cryopreservation cooling rate should be used (direct immersion in liquid nitrogen or freezing at temperatures below -130 °C), as well as fast thawing by direct immersion in a water bath at 35 °C.

  19. Mycorrhizal fungi isolated from native terrestrial orchids of pristine regions in Cordoba (Argentina).

    Science.gov (United States)

    Fernández Di Pardo, Agustina; Chiocchio, Viviana M; Barrera, Viviana; Colombo, Roxana P; Martinez, Alicia E; Gasoni, Laura; Godeas, Alicia M

    2015-03-01

    Orchidaceae is a highly dependent group on the Rhizoctonia complex that includes Ceratorhiza, Moniliopsis, Epulorhiza and Rhizoctonia, for seed germination and the development of new orchid plants. Thus, the isolation and identification of orchid mycorrhizal fungi are important to understand the orchid-fungus relationship, which can lead to the development of efficient conservation strategies by in vivo germination of seeds from endangered orchid plants. The aim of our work was to isolate and characterize the different mycorrhizal fungi found in roots of terrestrial orchids from Cordoba (Argentina), and, to learn about the natural habit and fungal associations in the Chaco Serrano woodland pristine region. In this study, bloomed orchid root and rhizosphere soil samples were obtained in two times from Valle de Punilla during spring of 2007; samples were kept in plastic bags until processed within 48 hours, and mycorrhizal condition confirmed assessing peloton presence. A total of 23 isolates of the orchideous mycorrhizal Rhizoctonia complex were obtained. The isolates were studied based on morphological characters and ITS-rDNA sequences. Morphological characteristics as color of colonies, texture, growth rate, hyphal diameter and length and presence of sclerotia were observed on culture media. To define the number of nuclei per cell, the isolates were grown in Petri dishes containing water-agar (WA) for three days at 25 degrees C and stained with Safranine-O solution. The mycorrhizal fungi were grouped into binucleate (MSGib, 10 isolates) and multinucleate (MSGim, 13 isolates) based on morphological characteristics of the colonies. We obtained the ITS1-5.8s-ITS4 region that was amplified using primers ITSI and ITS4. Based on DNA sequencing, isolates Q23 and Q29 were found to be related to species of Ceratobasidium. Isolates Q24 and Q4 were related to the binucleated anastomosis group AG-C of Rhizoctonia sp. The rest of the isolates grouped in the Ceratobasidium

  20. Mycorrhizal fungi isolated from native terrestrial orchids of pristine regions in Córdoba (Argentina

    Directory of Open Access Journals (Sweden)

    Agustina Fernández Di Pardo

    2015-03-01

    Full Text Available Orchidaceae is a highly dependent group on the Rhizoctonia complex that includes Ceratorhiza, Moniliopsis, Epulorhiza and Rhizoctonia, for seed germination and the development of new orchid plants. Thus, the isolation and identification of orchid mycorrhizal fungi are important to understand the orchid-fungus relationship, which can lead to the development of efficient conservation strategies by in vivo germination of seeds from endangered orchid plants. The aim of our work was to isolate and characterize the different mycorrhizal fungi found in roots of terrestrial orchids from Córdoba (Argentina, and, to learn about the natural habit and fungal associations in the Chaco Serrano woodland pristine region. In this study, bloomed orchid root and rhizosphere soil samples were obtained in two times from Valle de Punilla during spring of 2007; samples were kept in plastic bags until processed within 48 hours, and mycorrhizal condition confirmed assessing peloton presence. A total of 23 isolates of the orchideous mycorrhizal Rhizoctonia complex were obtained. The isolates were studied based on morphological characters and ITS-rDNA sequences. Morphological characteristics as color of colonies, texture, growth rate, hyphal diameter and length and presence of sclerotia were observed on culture media. To define the number of nuclei per cell, the isolates were grown in Petri dishes containing water-agar (WA for three days at 25°C and stained with Safranine-O solution. The mycorrhizal fungi were grouped into binucleate (MSGib, 10 isolates and multinucleate (MSGim, 13 isolates based on morphological characteristics of the colonies. We obtained the ITS1-5.8s-ITS4 region that was amplified using primers ITS1 and ITS4. Based on DNA sequencing, isolates Q23 and Q29 were found to be related to species of Ceratobasidium. Isolates Q24 and Q4 were related to the binucleated anastomosis group AG-C of Rhizoctonia sp. The rest of the isolates grouped in the

  1. Are there keystone mycorrhizal fungi associated to tropical epiphytic orchids?

    Science.gov (United States)

    Cevallos, Stefania; Sánchez-Rodríguez, Aminael; Decock, Cony; Declerck, Stéphane; Suárez, Juan Pablo

    2017-04-01

    In epiphytic orchids, distinctive groups of fungi are involved in the symbiotic association. However, little is known about the factors that determine the mycorrhizal community structure. Here, we analyzed the orchid mycorrhizal fungi communities associated with three sympatric Cymbidieae epiphytic tropical orchids (Cyrtochilum flexuosum, Cyrtochilum myanthum, and Maxillaria calantha) at two sites located within the mountain rainforest of southern Ecuador. To characterize these communities at each orchid population, the ITS2 region was analyzed by Illumina MiSeq technology. Fifty-five mycorrhizal fungi operational taxonomic units (OTUs) putatively attributed to members of Serendipitaceae, Ceratobasidiaceae and Tulasnellaceae were identified. Significant differences in mycorrhizal communities were detected between the three sympatric orchid species as well as among sites/populations. Interestingly, some mycorrhizal OTUs overlapped among orchid populations. Our results suggested that populations of studied epiphytic orchids have site-adjusted mycorrhizal communities structured around keystone fungal species. Interaction with multiple mycorrhizal fungi could favor orchid site occurrence and co-existence among several orchid species.

  2. Real-time PCR and microscopy: Are the two methods measuring the same unit of arbuscular mycorrhizal fungal abundance?

    NARCIS (Netherlands)

    Gamper, H.A.; Young, J.P.W.; Jones, D.L.; Hodge, A.

    2008-01-01

    To enable quantification of mycelial abundance in mixed-species environments, eight new TaqMan® real-time PCR assays were developed for five arbuscular mycorrhizal fungal (AMF, Glomeromycota) taxa. The assays targeted genes encoding 18S rRNA or actin, and were tested on DNA from cloned gene

  3. Laser microdissection and its application to analyze gene expression in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Gomez, S Karen; Harrison, Maria J

    2009-05-01

    Phosphorus is essential for plant growth, and in many soils phosphorus availability limits crop production. Most plants in natural ecosystems obtain phosphorus via a symbiotic partnership with arbuscular mycorrhizal (AM) fungi. While the significance of these associations is apparent, their molecular basis is poorly understood. Consequently, the potential to harness the mycorrhizal symbiosis to improve phosphorus nutrition in agriculture is not realized. Transcript profiling has recently been used to investigate gene expression changes that accompany development of the AM symbiosis. While these approaches have enabled the identification of AM-symbiosis-associated genes, they have generally involved the use of RNA from whole mycorrhizal roots. Laser microdissection techniques allow the dissection and capture of individual cells from a tissue. RNA can then be isolated from these samples and cell-type specific gene expression information can be obtained. This technology has been applied to obtain cells from plants and more recently to study plant-microbe interactions. The latter techniques, particularly those developed for root-microbe interactions, are of relevance to plant-parasitic weed research. Here, laser microdissection, its use in plant biology and in particular plant-microbe interactions are discussed. An overview of the AM symbiosis is then provided, with a focus on recent advances in understanding development of the arbuscule-cortical cell interface. Finally, the recent applications of laser microdissection for analyses of AM symbiosis are discussed.

  4. The survival successes of mycorrhizal and non- mycorrhizal ...

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... In the detailed planting applications of landscape architecture, the negativities created by insufficiencies in ecological conditions and care interferences create effects that increase economical losses. On the other hand, the drought in summer is an important problem. As a result, the plant development ...

  5. Further advances in orchid mycorrhizal research.

    Science.gov (United States)

    Dearnaley, John D W

    2007-09-01

    Orchid mycorrhizas are mutualistic interactions between fungi and members of the Orchidaceae, the world's largest plant family. The majority of the world's orchids are photosynthetic, a small number of species are myco-heterotrophic throughout their lifetime, and recent research indicates a third mode (mixotrophy) whereby green orchids supplement their photosynthetically fixed carbon with carbon derived from their mycorrhizal fungus. Molecular identification studies of orchid-associated fungi indicate a wide range of fungi might be orchid mycobionts, show common fungal taxa across the globe and support the view that some orchids have specific fungal interactions. Confirmation of mycorrhizal status requires isolation of the fungi and restoration of functional mycorrhizas. New methods may now be used to store orchid-associated fungi and store and germinate seed, leading to more efficient culture of orchid species. However, many orchid mycorrhizas must be synthesised before conservation of these associations can be attempted in the field. Further gene expression studies of orchid mycorrhizas are needed to better understand the establishment and maintenance of the interaction. These data will add to efforts to conserve this diverse and valuable association.

  6. Using deep RNA sequencing for the structural annotation of the Laccaria bicolor mycorrhizal transcriptome.

    Directory of Open Access Journals (Sweden)

    Peter E Larsen

    Full Text Available BACKGROUND: Accurate structural annotation is important for prediction of function and required for in vitro approaches to characterize or validate the gene expression products. Despite significant efforts in the field, determination of the gene structure from genomic data alone is a challenging and inaccurate process. The ease of acquisition of transcriptomic sequence provides a direct route to identify expressed sequences and determine the correct gene structure. METHODOLOGY: We developed methods to utilize RNA-seq data to correct errors in the structural annotation and extend the boundaries of current gene models using assembly approaches. The methods were validated with a transcriptomic data set derived from the fungus Laccaria bicolor, which develops a mycorrhizal symbiotic association with the roots of many tree species. Our analysis focused on the subset of 1501 gene models that are differentially expressed in the free living vs. mycorrhizal transcriptome and are expected to be important elements related to carbon metabolism, membrane permeability and transport, and intracellular signaling. Of the set of 1501 gene models, 1439 (96% successfully generated modified gene models in which all error flags were successfully resolved and the sequences aligned to the genomic sequence. The remaining 4% (62 gene models either had deviations from transcriptomic data that could not be spanned or generated sequence that did not align to genomic sequence. The outcome of this process is a set of high confidence gene models that can be reliably used for experimental characterization of protein function. CONCLUSIONS: 69% of expressed mycorrhizal JGI "best" gene models deviated from the transcript sequence derived by this method. The transcriptomic sequence enabled correction of a majority of the structural inconsistencies and resulted in a set of validated models for 96% of the mycorrhizal genes. The method described here can be applied to improve gene

  7. Shifts in soil fungal communities in Tuber melanosporum plantations over a 20-year transition from agriculture fields to oak woodlands

    Directory of Open Access Journals (Sweden)

    Liu Bing

    2016-04-01

    Full Text Available Aim of study: To explore the diversity of soil fungi found in black truffle (Tuber melanosporum plantations following the introduction of the mycorrhizal-colonized host tree, (Quercus ilex, through the development of the brûlé and production of mature sporocarps.Area of study: This research was carried out province of Teruel, Aragon (central eastern Spain.Material and Methods: Soil samples from 6 plantations were collected beneath Q. ilex trees inoculated with T. melanosporum, of 3, 5, 7, 10, 14 and 20 years after out planting in truffle plantations. Soil DNA was extracted, PCR-amplified and sequenced to compare soil fungi present at different ages.Main results: As tree age increased, we observed an increased frequency of T. melanosporum (from 8% to 71% of sequenced colonies and concomitant decrease in the combined frequency of Fusarium spp. and Phoma spp. (from 64% to 3%.Research highlights: There are important shifts in species richness and in functional groups in the soil fungal communities in maturing black truffle-oak woodland plantations. The observed inverse relationship between the frequency of soil endophytic and/or pathogenic fungi and that of the mycorrhizal mutualist T. melanosporum provides support to continue a deeper analysis of shifts in fungal communities and functional groups where there is a transition from agriculture fields to woodlands.Abbreviations used: Ectomycorrhiza (ECM fungus; Vesicular arbuscular mycorrhiza (VAM; Operational taxonomic unit (OTU.

  8. Molecular trait indicators: moving beyond phylogeny in arbuscular mycorrhizal ecology.

    NARCIS (Netherlands)

    Gamper, H.A.; van der Heijden, M.G.A.; Kowalchuk, G.A.

    2010-01-01

    Arbuscular mycorrhizal (AM) fungi form symbiotic associations with the roots of most plants, thereby mediating nutrient and carbon fluxes, plant performance, and ecosystem dynamics. Although considerable effort has been expended to understand the keystone ecological position of AM symbioses, most

  9. Diversity and biogeography of arbuscular mycorrhizal fungi in agricultural soils

    Czech Academy of Sciences Publication Activity Database

    Oehl, F.; Laczko, E.; Oberholzer, H.-R.; Jansa, Jan; Egli, S.

    2017-01-01

    Roč. 53, č. 7 (2017), s. 777-797 ISSN 0178-2762 Institutional support: RVO:61388971 Keywords : Arbuscular mycorrhizal * Agriculture * Biodiversity Subject RIV: EE - Microbiology, Virology Impact factor: 3.683, year: 2016

  10. Mycorrhizal responses to biochar in soil-concepts and mechanisms.

    NARCIS (Netherlands)

    Warnock, D.D.; Lehmann, J.; Kuyper, T.W.; Rillig, M.C.

    2007-01-01

    Experiments suggest that biomass-derived black carbon (biochar) affects microbial populations and soil biogeochemistry. Both biochar and mycorrhizal associations, ubiquitous symbioses in terrestrial ecosystems, are potentially important in various ecosystem services provided by soils, contributing

  11. Molecular characterisation of a mycorrhizal inoculant that enhances ...

    African Journals Online (AJOL)

    SERVER

    2007-07-04

    . 1988; Smith and Read 1996, Smith et al. 1993). Under many natural or man made water stress conditions, arbuscular mycorrhizal fungi can play an important role. *Corresponding author. E-mail: zomure@yahoo.com. Tél: 00.

  12. Role of arbuscular mycorrhizal fungi in phytoremediation of heavy ...

    African Journals Online (AJOL)

    Role of arbuscular mycorrhizal fungi in phytoremediation of heavy metals and effects on growth and biochemical activities of wheat (Triticum aestivum L.) plants in Zn contaminated soils. Sadia Kanwal, Asma Bano, Riffat Naseem Malik ...

  13. Arbuscular mycorrhizal fungi and colonization stimulant in cotton and maize

    National Research Council Canada - National Science Library

    Fabrício Henrique Moreira Salgado; Fátima Maria de Sousa Moreira; José Oswaldo Siqueira; Ricardo Henrique Barbosa; Helder Barbosa Paulino; Marco Aurélio Carbone Carneiro

    The objective of this study was to evaluate the effects of inoculation with different arbuscular mycorrhizal fungi native to Cerrado, associated with the application of colonization stimulant (7-hydroxy, 4’-methoxy-isoflavone...

  14. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

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

    2016-01-01

    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

  15. Inoculation of Ceratonia siliqua L. with native arbuscular mycorrhizal ...

    African Journals Online (AJOL)

    Inoculation of Ceratonia siliqua L. with native arbuscular mycorrhizal fungi mixture improves seedling establishment under greenhouse conditions. Ouahmane Lahcen, Ndoye Ibrahima, Morino Abdessadek, Ferradous Abderrahim, Sfairi Youssef, Al Faddy Mohamed Najib, Abourouh Mohamed ...

  16. Mycorrhizal symbiosis: ancient signalling mechanisms co-opted

    NARCIS (Netherlands)

    Geurts, R.; Vleeshouwers, V.G.A.A.

    2012-01-01

    Mycorrhizal root endosymbiosis is an ancient property of land plants. Two parallel studies now provide novel insight into the mechanism driving this interaction and how it is used by other filamentous microbes like pathogenic oomycetes.

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

    Science.gov (United States)

    2012-01-01

    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. PMID:23046713

  18. 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.

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

    Science.gov (United States)

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

    2012-10-09

    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. 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. 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. Seletion of arbuscular mycorrhizal and ectomycorrhizal fungi for efficient symbiosis with Acacia mangium willd

    Directory of Open Access Journals (Sweden)

    Guilherme Augusto Robles Angelini

    2013-12-01

    Full Text Available Acacia mangium forms two kinds of mycorrhizal symbiosis, a arbuscular mycorrhizal fungi (AMFs type and another with ectomycorrhizal fungi (fECTOs. The present study aimed to select different AMFs species and fECTOs isolates for effective symbiosis with A. mangium, which provide seedlings well colonized, nodulated and developed. Experiments were conducted in a greenhouse at Embrapa Agrobiology, one for AMF species selection and another for fECTOs, using a randomized block design with five replicates. Treatments were species AMFs (Acaulospora laevis, Acaulospora morrowiae, Entrophospora colombiana, Entrophospora contigua, Gigaspora margarita, Glomus clarum, Scutellospora calospora, Scutellospora heterogama, Scutellospora gilmorei and Scutellospora pellucida or fECTOs isolated (UFSC Pt116; UFSC Pt24; UFSC Pt193; O 64–ITA6; UFSC Pt187 and O 40–ORS 7870. The AMFs species that promoted greater vegetative growth, mycorrhizal colonization and more effective symbioses were S. calospora, S. heterogama, S. gilmorei e A. morrowiae. The fECTOs not demonstrated effectiveness in promoting growth, but the isolate O64-ITA6 (Pisolithus tinctorius provided greater colonization. Seedlings of A. mangium have high responsiveness to inoculation with AMFs and depends on high root colonization, between 40 and 80%, to obtain relevant benefits from symbiose over nodule formation and growth.

  1. Association and mycorrhizal dependency in Jatropha curcas L. seedlings under salt stress

    Directory of Open Access Journals (Sweden)

    Dilliani Felipe Barros de Oliveira

    Full Text Available ABSTRACT The cultivation of Jatropha curcas L. for biodiesel production is possible in salinized areas; however, biomass production is limited in these soils. Arbuscular mycorrhizal fungi (AMF are a promising alternative for bioremediation in salinized soils. Yet, salinity also affects the AMF at the time of colonization and, in this case, the symbiosis is not always established. Therefore, the aim of this study was to test the hypotheses that three AMF species commonly found in saline soils are associated with J. curcas and if seedlings previously inoculated with these AMF are more tolerant to salt stress. Two trials were performed: the first one was carried out in a completely randomized design with five treatments (control, Rhizophagus intraradices, Gigaspora albida, Claroideoglomus etunicatum, and the three species together and six repetitions to investigate the formation of symbiosis among species; and the second trial was carried out in randomized blocks in a 4 × 2 factorial scheme (2, 5, 8, and 10 dS m-1, with and without mycorrhizae with eight repetitions to verify the development and mycorrhizal dependency (MD of the seedlings previously inoculated, in salinized environment. The three species of AMF are associated with J. curcas both alone and together. Mycorrhizal dependency increased with salinity, indicating that J. curcas is a facultative species. The pre-colonized seedlings with AMF are an alternative to the establishment of J. curcas in salinized soils.

  2. Something old, something new: auxin and strigolactone interact in the ancient mycorrhizal symbiosis.

    Science.gov (United States)

    Foo, Eloise

    2013-04-01

    Arbuscular mycorrhizal symbiosis, formed between more than 80% of land plants and fungi from the phylum Glomeromycota, is an ancient association that is believed to have evolved as plants moved onto land more than 400 mya. Similarly ancient, the plant hormones auxin and strigolactone are thought to have been present in the plant lineage since before the divergence of the bryophytes in the case of auxin and before the colonisation of land in the case of strigolactones. The discovery of auxin in the 1930s predates the discovery of strigolactones as a plant hormone in 2008 by over 70 y. Recent studies in pea suggest that these two signals may interact to regulate mycorrhizal symbiosis. Furthermore, the first quantitative studies are presented that show that low auxin content of the root is correlated with low strigolactone production, an interaction that has implications for how these plant hormones regulate several developmental programs including shoot branching, secondary growth and root development. With recent advances in our understanding of auxin and strigolactone biosynthesis, together with the discovery of the fungal signals that activate the plant host, the stage is set for real breakthroughs in our understanding of the interactions between plant and fungal signals in mycorrhizal symbiosis.

  3. Preliminary findings on identification of mycorrhizal fungi from diverse orchids in the Central Highlands of Madagascar.

    Science.gov (United States)

    Yokoya, Kazutomo; Zettler, Lawrence W; Kendon, Jonathan P; Bidartondo, Martin I; Stice, Andrew L; Skarha, Shannon; Corey, Laura L; Knight, Audrey C; Sarasan, Viswambharan

    2015-11-01

    The Orchid flora of Madagascar is one of the most diverse with nearly 1000 orchid taxa, of which about 90% are endemic to this biodiversity hotspot. The Itremo Massif in the Central Highlands of Madagascar with a Highland Subtropical climate range encompasses montane grassland, igneous and metamorphic rock outcrops, and gallery and tapia forests. Our study focused on identifying culturable mycorrhizae from epiphytic, lithophytic, and terrestrial orchid taxa to understand their diversity and density in a spatial matrix that is within the protected areas. We have collected both juvenile and mature roots from 41 orchid taxa for isolating their orchid mycorrhizal fungi (OMF), and to culture, identify, and store in liquid nitrogen for future studies. Twelve operational taxonomic units (OTUs), of three known orchid mycorrhizal genera, were recognized by analysis of internal transcribed spacer (ITS) sequences of 85 isolates, and, by comparing with GenBank database entries, each OTU was shown to have closely related fungi that were also found as orchid associates. Orchid and fungal diversity were greater in gallery forests and open grasslands, which is very significant for future studies and orchid conservation. As far as we know, this is the first ever report of detailed identification of mycorrhizal fungi from Madagascar. This study will help start to develop a programme for identifying fungal symbionts from this unique biodiversity hotspot, which is undergoing rapid ecosystem damage and species loss. The diversity of culturable fungal associates, their density, and distribution within the Itremo orchid hotspot areas will be discussed.

  4. 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...... 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....

  5. Glyphosate drift affects arbuscular mycorrhizal association in coffee

    OpenAIRE

    Carvalho,F.P.; Souza,B.P.; França,A.C.; Ferreira,E.A.; Franco,M.H.R.; Kasuya,M.C.M.; Ferreira,F.A.

    2014-01-01

    Mycorrhizal association promotes better survival and nutrition of colonized seedling on field, and consequently, increasing of productivity. However, the weed management can interfere on this association, due to incorrect use of glyphosate. This work has assessed the effects of glyphosate drift on the growth and nutrition of arabica coffee plants (Catuaí Vermelho - IAC 99) colonized with arbuscular mycorrhizal fungi (AMF). The experiment was conducted in 2 x 5 factorial scheme, and included i...

  6. Combining metabolomics and gene expression analysis reveals that propionyl- and butyryl-carnitines are involved in late stages of arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Laparre, Jérôme; Malbreil, Mathilde; Letisse, Fabien; Portais, Jean Charles; Roux, Christophe; Bécard, Guillaume; Puech-Pagès, Virginie

    2014-03-01

    The arbuscular mycorrhizal (AM) symbiosis is a widespread mutualistic association between soil fungi (Glomeromycota) and the roots of most plant species. AM fungi are obligate biotrophs whose development is partially under the control of their plant host. We explored the possibility to combine metabolomic and transcriptomic approaches to find putative mycorrhiza-associated metabolites regulating AM fungal development. Methanol extracts of Medicago truncatula roots colonized or not with the AM fungus Rhizophagus irregularis were analyzed and compared by ultra-high-performance liquid chromatography (UHPLC), high-resolution mass spectrometry (Q-TOF), and multivariate statistical discrimination. We detected 71 mycorrhiza-associated analytes exclusively present or at least 10-fold more abundant in mycorrhizal roots. To identify among these analytes those that could regulate AM fungal development, we fractionated by preparative and semi-preparative HPLC the mycorrhizal and non-mycorrhizal root extracts and established how the 71 analytes were distributed among the fractions. Then we tested the activity of the fractions on germinating spores of R. irregularis by quantifying the expression of 96 genes known for their diverse in planta expression patterns. These investigations reveal that propionyl- and butyryl-carnitines accumulated in mycorrhizal roots. The results suggest that these two molecules regulate fungal gene expression in planta and represent interesting candidates for further biological characterization.

  7. 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

    2011-09-01

    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.

  8. 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.

  9. Effect of polyaromatic hydrocarbons in soil on arbuscular mycorrhizal plants

    Energy Technology Data Exchange (ETDEWEB)

    Leyval, C.; Binet, P. [H. Poincare University, Vandoeuvre-les-Nancy (France). Centre de Pedologie Biologique

    1998-03-01

    The rhizosphere of plants plays a role in the bioremediation of soils polluted with organic pollutants such as polyaromatic hydrocarbons (PAHs). Arbuscular mycorrhizal (AM) fungi provide a direct link between soil and plant roots, but very little is known of the interactions between PAHs and AM fungi. The effect of PAHs on mycorrhizal colonization in polluted soil were studied and the effect of AM fungi on plant growth in these soils. Lee (Allium porrum L.), maize (Zea mays L.), ryegrass (Lolium perenne L.), and clover (Trifolium subterraneum L.) were grown in pots containing a soil artificially contaminated with increasing concentrations of anthracene or mixed with an industrial soil polluted with PAHs. Mycorrhizal colonization by the indigenous AM population of the nonpolluted soil was not significantly affected by the addition of anthracene up to 10 g kg{sup -1}. However, mycorrhizal colonization of clover and leek decreased when the industrial soil was added to the nonpolluted soil, while maize and ryegrass colonization was not affected. The effect of PAHs on plant survival and growth depended on plant species. Inoculation of ryegrass with Glomus mosseae improved plant survival and plant growth in the industrially polluted soil. At 5 g of PAH kg{sup -1} only mycorrhizal plants survived. Mycorrhizal fungi may contribute to the establishment and maintenance of plants in PAH-polluted soils. 34 refs., 3 figs., 4 tabs.

  10. Leaf metabolome in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Schweiger, Rabea; Müller, Caroline

    2015-08-01

    Most land plants are associated with arbuscular mycorrhizal fungi, which colonise the plant roots and facilitate the uptake of water and nutrients. In turn, the fungi receive plant carbohydrates. Although the fungus is morphologically restricted to the roots, the exchange of substances and involvement of phytohormone signalling has consequences on systemic shoot tissues. Recent research provides growing insight in the species-specificity of leaf metabolic responses to arbuscular mycorrhiza, revealing that various metabolites can be affected. Such mycorrhiza-mediated changes in the chemical composition of leaf tissues can confer phytoprotection against different abiotic stresses. Moreover, they have consequences on numerous biotic interactions. In this review we highlight such findings and point out fields where more research is required. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The arbuscular mycorrhizal symbiosis attenuates symptom severity and reduces virus concentration in tomato infected by Tomato yellow leaf curl Sardinia virus (TYLCSV).

    Science.gov (United States)

    Maffei, Giulia; Miozzi, Laura; Fiorilli, Valentina; Novero, Mara; Lanfranco, Luisa; Accotto, Gian Paolo

    2014-04-01

    The arbuscular mycorrhizal (AM) symbiosis is considered a natural instrument to improve plant health and productivity since mycorrhizal plants often show higher tolerance to abiotic and biotic stresses. However, the impact of the AM symbiosis on infection by viral pathogens is still largely uncertain and little explored. In the present study, tomato plants were grown under controlled conditions and inoculated with the AM fungus Funneliformis mosseae. Once the mycorrhizal colonization had developed, plants were inoculated with the Tomato yellow leaf curl Sardinia virus (TYLCSV), a geminivirus causing one of the most serious viral diseases of tomatoes in Mediterranean areas. Biological conditions consisted of control plants (C), TYLCSV-infected plants (V), mycorrhizal plants (M), and TYLCSV-infected mycorrhizal plants (MV). At the time of analysis, the level of mycorrhiza development and the expression profiles of mycorrhiza-responsive selected genes were not significantly modified by virus infection, thus indicating that the AM symbiosis was unaffected by the presence and spread of the virus. Viral symptoms were milder, and both shoot and root concentrations of viral DNA were lower in MV plants than in V plants. Overall F. mosseae colonization appears to exert a beneficial effect on tomato plants in attenuating the disease caused by TYLCSV.

  12. Germinação de sementes e desenvolvimento de protocormos de Epidendrum secundum Jacq. (Orchidaceae em associação com fungos micorrízicos do gênero Epulorhiza Seed germination and protocorm development of Epidendrum secundum Jacq. (Orchidaceae in association with Epulorhiza mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Marlon Corrêa Pereira

    2011-09-01

    Full Text Available Na natureza, as espécies de Orchidaceae estão associadas a fungos micorrízicos. A compreensão da especificidade fungo-planta nessa associação pode auxiliar no desenvolvimento de programas para propagação simbiótica das orquídeas. Fungos micorrízicos Epulorhiza spp. têm sido isolados de Epidendrum secundum Jacq. com maior freqüência. Assim, o objetivo deste trabalho foi avaliar a germinação de sementes e o desenvolvimento de protocormos de E. secundum associados a diferentes isolados de fungos do gênero Epulorhiza. Utilizou-se 16 fungos Epulorhiza spp. isolados de diferentes populações de E. secundum. Após 44 dias, todos os fungos testados induziram a germinação das sementes. Entretanto, observou-se diferença na eficiência desses fungos em promover o desenvolvimento dos protocormos, mesmo entre os fungos que apresentam semelhanças morfológicas. O estágio de desenvolvimento mais avançado dos protocormos e o maior índice de crescimento foram observados quando as sementes foram inoculadas com o isolado M65. Conclui-se que a germinação das sementes e o desenvolvimento dos protocormos de E. secundum dependem do fungo micorrízico e que, apesar da grande freqüência de associação entre essa espécie de orquídea e fungos do gênero Epulorhiza, é importante a seleção de isolados que apresentem maior eficiência simbiótica. Isolados eficientes são úteis na produção de mudas de orquídeas de importância econômica e ornamental e de espécies ameaçadas de extinção.In nature, species of Orchidaceae are always associated with mycorrhizal fungi. The comprehension of fungal-plant specificity in this association can assist with the establishment of programs that focus on symbiotic propagation of orchids. Epulorhiza mycorrhizal fungi have frequently been isolated from Epidendrum secundum Jacq. Thus, the objective of this study was to evaluate the germination of E. secundum seeds and protocorm development associated

  13. Plant litter chemistry and mycorrhizal roots promote a nitrogen feedback in a temperate forest.

    Science.gov (United States)

    Nina Wurzburger; Ronald L. Hendrick

    2009-01-01

    1. Relationships between mycorrhizal plants and soil nitrogen (N) have led to the speculation that the chemistry of plant litter and the saprotrophy of mycorrhizal symbionts can function together to...

  14. Analysis of network architecture reveals phylogenetic constraints on mycorrhizal specificity in the genus Orchis (Orchidaceae)

    National Research Council Canada - National Science Library

    Hans Jacquemyn; Vincent Merckx; Rein Brys; Daniel Tyteca; Bruno P. A. Cammue; Olivier Honnay; Bart Lievens

    2011-01-01

    ... of the mycorrhizal specificity of orchids. Here, we used a network analysis approach to investigate orchid mycorrhizal associations in 16 species of the genus Orchis sampled across 11 different regions in Europe...

  15. Responses of Mycorrhizal Symbioses to Deliberate Leaks from AN Experimental CO2 Sequestration Field: the Zert Site

    Science.gov (United States)

    Apple, M. E.; Rowe, J. O.; Zhou, X.; Jewell, S.; Dobeck, L.; Cunningham, A.; Spangler, L.

    2012-12-01

    Carbon sequestration is a means of reducing the concentration of atmospheric CO2 . It is important to monitor carbon sequestration fields for surface detection of possible leaks of CO2 . At The Zero Emissions Research Technology (ZERT) site, CO2 is injected at 0.15 tonnes/day increased to 0.3 tonnes/day into the soil through a shallow horizontal injection well with deliberate zones of leaking CO2 , which wells up through the soil and reaches concentrations of 16% w/v. The ZERT site is an experimental facility designed for developing means of surface detection of leaking CO2 and for determining the responses of plants to very high soil CO2 . Within 1 - 2 weeks of CO2 injections, dandelions and grasses begin to form circular zones of leaf dieback called hot spots. While the hotspots are visually apparent, the responses of the underground mycorrhizal symbioses to very high soil CO2 at the ZERT site are as yet undetermined. To examine the effects of leaking CO2 on mycorrhizae, we collected soil and root samples between and at the hotspots before CO2 was injected, then inoculated the rhizosphere with mycorrhizal inoculum containing spores of Glomus and Gigaspora sp., and resampled the soil and roots after three weeks of CO2 injection. We then evaluated the samples for percent mycorrhizal colonization via the line-intercept method in cleared roots in which fungal structures were stained with India-ink. Plants with mycorrhizal fungi benefit by improved P uptake, so we hypothesize that where plants have increased anthocyanin production, a symptom of P deficiency, mycorrhizal colonization would be reduced. In previous summers of the ZERT experiments, leaves have turned red/purple with CO2 exposure, and as of August, 2012, current year leaves appear to have increased anthocyanin above hotspots. Plant roots exude organic carbon into the soil, where it is used by mycorrhizal fungi. Mycorrhizal symbioses are key in the carbon dynamics of soil and in linking the above and below

  16. Arbuscular mycorrhizal symbiosis of Thymus kotschyamus Boiss. & Hohen. in relation with soil elements during spring and autumn in Noujian Watershed (Lorestan province

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    Parvin Ramak

    2016-06-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF are the most important microorganisms of soil having an important role in soil fertility. In this research, the correlation between soil nutrient elements and Arbuscular mycorrhizal fungi colonization and spore numbers in the rhizosphere of Thymus kotschyamus Boiss. & Hohen. growing in the three regions (Taf, Vark and Kohkala of Noujian watershed were studied during spring and autumn. Influence of arbuscular mycorrhizal symbiosis were also determined on vegetative characteristics and essential oil yield of T. kotschyamus.The results indicated that magnesium significant positive correlation with arbuscular mycorrhiza fungi spore density (+0.84 and percentage colonization (+0.92. Soil organic matter no significant linear correlation with arbuscular mycorrhiza fungi spore density and percentage colonization. Potassium negatively correlated with spore density and percentage colonization respectively; -0.85 and -0.90. Arbuscular mycorrhizal fungi colonization significant linear correlation with dry weight (+0.79. Essential oil yield of T. kotschyamus positively correlated with that of spore density and percentage colonization respectively; +0.93 and +0.91. Given the importance of mycorrhizal symbiosis and compilation this with soil elements, this information can be useful for development of medicinal plants in agricultural ecosystems.

  17. 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.

  18. Enhanced Tomato Disease Resistance Primed by Arbuscular Mycorrhizal Fungus

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    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

  19. Nitrogen Pollution Shifts Forest Mycorrhizal Associations at Continental Scale

    Science.gov (United States)

    Averill, C.; Talbot, J. M.; Dietze, M.

    2016-12-01

    Most trees on Earth form a symbiosis with either ectomycorrhizal or arbuscular mycorrhizal fungi. The type of association has demonstrated importance for understanding ecosystem carbon (C) and nitrogen (N) cycling. Furthermore, the effect is independent of other dominant drivers of ecosystem function: climate, mineralogy and organic matter chemistry. Given this, it becomes important to understand where different mycorrhizal associations are, what controls their distribution, and where they will be in the future. Here we analyze 3,000 forest inventory plots from the United State Forest Inventory and Analysis data set. We categorize forest basal area as ecto- or arbuscular mycorrhizal associated to generate a metric of the relative abundance of ectomycorrhizal trees (ectomycorrhizal basal area / ecto- + arbuscular mycorrhizal basal area). We model this abundance as a function of climate, soil chemical properties (pH and C:N stoichiometry), and atmospheric N deposition. We hypothesized that N pollution in the United States has affected the relative abundance of different mycorrhizal associations, and that this would be reflected in forest composition. Overall, models showed that climate, soil chemistry, and N deposition were important for predicting the current relative abundance of ecto- and arbuscular associated trees. Ectomycorrhizal trees were more abundant in cold and wet climates compared to hot and dry. Low soil pH and high soil C:N ratios were also associated with an increase in the relative abundance of ectomycorrhizal trees. Most interesting, there was a significant influence of N deposition on the relative abundance of different mycorrhizal associations. N deposition reduced the abundance of ectomycorrhizal compared to arbuscular mycorrhizal associated trees independent of climate and soil chemistry. Given the known associations between ectomycorrhizal dominance and soil C stabilization, we argue that N pollution in the United States has shifted the forest

  20. Mycorrhizal symbiosis produces changes in specific flavonoids in leaves of pepper plant (Capsicum annum L.)

    Science.gov (United States)

    In this study, experiments were performed to investigate if mycorrhizal plants grown under optimal growth conditions would improve crop quality compared to the non-mycorrhizal control. The results clearly showed that while mycorrhizal plants grown under an optimal nutrient supply did not increase t...

  1. Differences in arbuscular mycorrhizal fungi among three coffee cultivars in Puerto Rico

    Science.gov (United States)

    Ligia Lebrón; Jean D. Lodge; Paul. Bayman

    2012-01-01

    Mycorrhizal symbiosis is important for growth of coffee (Coffea arabica), but differences among coffee cultivars in response to mycorrhizal interactions have not been studied. We compared arbuscular mycorrhizal (AM) extraradical hyphae in the soil and diversity of AM fungi among three coffee cultivars, Caturra, Pacas, and Borbon, at three farms in...

  2. Mycorrhizal inoculation affects the phytochemical content in strawberry fruits

    Directory of Open Access Journals (Sweden)

    Ana Paula Cecatto

    2016-04-01

    Full Text Available The aim of this research was to evaluate the effect of the inoculation date of arbuscular mycorrhizal fungi on the fruit quality and the content of phytochemicals in a strawberry soilless growing system. The experiment was performed in Huelva (Spain and was conducted in a greenhouse on the La Rábida Campus of Huelva University under natural light and temperature from October 2013 to June 2014. Three short-day strawberry cultivars (‘Splendor’, ‘Sabrina’ and ‘Fortuna’ were grown in polyethylene bags filled with coconut fibres. Randomized block design, with 3 repetitions and factorial arrangement (3 cultivars x 3 treatments, was established. Each replicate consisted of one bag with 12 plants supporting structures at 40 cm height. The treatments were: T1 = mycorrhizal inoculation in the transplantation; T2 = mycorrhizal inoculation 30 days after transplantation (DAT; and T0 = control treatment, without inoculation. Arbuscular mycorrhizal fungi inoculation significantly affected the contents of anthocyanin and phenolics. When the inoculation is performed in the transplantation, the fruits showed a high content of anthocyanin and total phenolics. The mycorrhizal inoculation influences decreasing the acidity in fruit throughout the growing season and increase firmness only during the early stage of production.

  3. Mycorrhizal associations as Salix repens L. communities in succession of dune ecosystems II Mycorrhizal dynamics and interactions of ectomycorrhizal and arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    Heijden, van der E.W.; Vosatka, M.

    2000-01-01

    Ectomycorrhizal (EcM) and arbuscular mycorrhizal (AM) associations of Salix repens were studied at 16 sites in different successional stages of dune ecosystems (calcareous-acidic, dry-wet) in the Netherlands. High EcM colonization, low AM colonization, and lack of differences between habitats

  4. Biofertilizers and sustainable agriculture: exploring arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Igiehon, Nicholas O; Babalola, Olubukola O

    2017-06-01

    Worldwide agricultural food production has to double in 2050 so as to feed the global increasing population while reducing dependency on conventional chemical fertilizers plus pesticides. To accomplish this objective, there is the need to explore the several mutualistic interactions between plant roots and rhizosphere microbiome. Biofertilization is the process of boosting the abundance of microorganisms such as arbuscular mycorrhizal fungi (AMF) in the natural plant rhizosphere which depicts a beneficial alternative to chemical fertilization practices. Mineral nutrients uptake by AMF are plausible by means of transporters coded for by different genes and example include phosphate transporter. These fungi can be produced industrially using plant host and these, including the possibility of AMF contamination by other microorganism, are factors militating against large scale production of AMF. AMF isolates can be inoculated in the greenhouse or field, and it has been shown that AMF survival and colonization level were enhanced in soybeans grown on land that was previously cultivated with the same plant. Next generation sequencing (NGS) is now used to gain insight into how AMF interact with indigenous AMF and screen for beneficial microbial candidates. Besides application as biofertilizers, novel findings on AMF that could contribute to maintenance of agricultural development include AMF roles in controlling soil erosion, enhancing phytoremediation, and elimination of other organisms that may be harmful to crops through common mycelia network. The combination of these potentials when fully harnessed under agricultural scenario will help to sustain agriculture and boost food security globally.

  5. Shoot- and root-borne cytokinin influences arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Cosme, Marco; Ramireddy, Eswarayya; Franken, Philipp; Schmülling, Thomas; Wurst, Susanne

    2016-10-01

    The arbuscular mycorrhizal (AM) symbiosis is functionally important for the nutrition and growth of most terrestrial plants. Nearly all phytohormones are employed by plants to regulate the symbiosis with AM fungi, but the regulatory role of cytokinin (CK) is not well understood. Here, we used transgenic tobacco (Nicotiana tabacum) with a root-specific or constitutive expression of CK-degrading CKX genes and the corresponding wild-type to investigate whether a lowered content of CK in roots or in both roots and shoots influences the interaction with the AM fungus Rhizophagus irregularis. Our data indicates that shoot CK has a positive impact on AM fungal development in roots and on the root transcript level of an AM-responsive phosphate transporter gene (NtPT4). A reduced CK content in roots caused shoot and root growth depression following AM colonization, while neither the uptake of phosphorus or nitrogen nor the root transcript levels of NtPT4 were significantly affected. This suggests that root CK may restrict the C availability from the roots to the fungus thus averting parasitism by AM fungi. Taken together, our study indicates that shoot- and root-borne CK have distinct roles in AM symbiosis. We propose a model illustrating how plants may employ CK to regulate nutrient exchange with the ubiquitous AM fungi.

  6. Signaling events during initiation of arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Schmitz, Alexa M; Harrison, Maria J

    2014-03-01

    Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal (AM) fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression. © 2014 Institute of Botany, Chinese Academy of Sciences.

  7. Plant Signaling and Metabolic Pathways Enabling Arbuscular Mycorrhizal Symbiosis.

    Science.gov (United States)

    MacLean, Allyson M; Bravo, Armando; Harrison, Maria J

    2017-10-01

    Plants have lived in close association with arbuscular mycorrhizal (AM) fungi for over 400 million years. Today, this endosymbiosis occurs broadly in the plant kingdom where it has a pronounced impact on plant mineral nutrition. The symbiosis develops deep within the root cortex with minimal alterations in the external appearance of the colonized root; however, the absence of macroscopic alterations belies the extensive signaling, cellular remodeling, and metabolic alterations that occur to enable accommodation of the fungal endosymbiont. Recent research has revealed the involvement of a novel N-acetyl glucosamine transporter and an alpha/beta-fold hydrolase receptor at the earliest stages of AM symbiosis. Calcium channels required for symbiosis signaling have been identified, and connections between the symbiosis signaling pathway and key transcriptional regulators that direct AM-specific gene expression have been established. Phylogenomics has revealed the existence of genes conserved for AM symbiosis, providing clues as to how plant cells fine-tune their biology to enable symbiosis, and an exciting coalescence of genome mining, lipid profiling, and tracer studies collectively has led to the conclusion that AM fungi are fatty acid auxotrophs and that plants provide their fungal endosymbionts with fatty acids. Here, we provide an overview of the molecular program for AM symbiosis and discuss these recent advances. © 2017 American Society of Plant Biologists. All rights reserved.

  8. 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.

  9. Arbuscular mycorrhizal fungi and mycorrhizal stimulant affect dry matter and nutrient accumulation in bean and soybean plants

    Directory of Open Access Journals (Sweden)

    Fabrício Henrique Moreira Salgado

    2016-12-01

    Full Text Available The adoption of biological resources in agriculture may allow less dependence and better use of finite resources. This study aimed at evaluating the effects of inoculation with arbuscular mycorrhizal fungi native to the Brazilian Savannah associated with the application of mycorrhizal stimulant (7-hydroxy, 4'-methoxy-isoflavone, in the early growth of common bean and soybean. The experiment was carried out in a greenhouse, in a completely randomized design, with a 7 x 2 factorial arrangement, consisting of five arbuscular mycorrhizal fungi species, joint inoculation (junction of all species in equal proportions and native fungi (without inoculation, in the presence and absence of stimulant. The following traits were evaluated: shoot dry matter, root dry matter, mycorrhizal colonization, nodules dry matter and accumulation of calcium, zinc and phosphorus in the shoot dry matter. The increase provided by the arbuscular mycorrhizal fungi and the use of stimulant reached over 200 % in bean and over 80 % in soybean plants. The fungi Acaulospora scrobiculata, Dentiscutata heterogama, Gigaspora margarita and Rhizophagus clarus, for bean, and Claroideoglomus etunicatum, Dentiscutata heterogama, Rhizophagus clarus and the joint inoculation, for soybean, increased the dry matter and nutrients accumulation.

  10. 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.

  11. Ceratobasidiaceae mycorrhizal fungi isolated from nonphotosynthetic orchid Chamaegastrodia sikokiana.

    Science.gov (United States)

    Yagame, Takahiro; Yamato, Masahide; Suzuki, Akira; Iwase, Koji

    2008-02-01

    Mycorrhizal fungi were isolated from the nonphotosynthetic orchid Chamaegastrodia sikokiana and identified as members of Ceratobasidiaceae by phylogenetic analysis of the internal transcribed spacer (ITS) region of ribosomal deoxyribonucleic acid. The ITS sequences were similar among geographically separated samples obtained from Mt. Kiyosumi in Chiba Prefecture and Mt. Yokokura in Kochi Prefecture. One of the isolated fungi, KI1-2, formed ectomycorrhiza on seedlings of Abies firma in pot culture, suggesting that tripartite symbiosis exists among C. sikokiana, mycorrhizal fungi, and A. firma in nature, and carbon compounds are supplied from A. firma to C. sikokiana through the hyphae of the mycorrhizal fungi. To our knowledge, this is the second study to suggest the involvement of Ceratobasidiaceae fungi in tripartite symbiosis with achlorophyllous orchids and photosynthetic host plants.

  12. The Genome of Laccaria Bi color Provides Insights into Mycorrhizal Symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F [UMR, France; Aerts, A. [U.S. Department of Energy, Joint Genome Institute; Ahren, D [Lund University, Sweden; Brun, A [UMR, France; Duchaussoy, F [UMR, France; Gibon, J [UMR, France; Kohler, A [UMR, France; Lindquist, E [U.S. Department of Energy, Joint Genome Institute; Pereda, V [UMR, France; Salamov, A. [U.S. Department of Energy, Joint Genome Institute; Shapiro, HJ [U.S. Department of Energy, Joint Genome Institute; Wuyts, J [UMR, France; Blaudez, D [UMR, France; Buee, M [UMR, France; Brokstein, P [U.S. Department of Energy, Joint Genome Institute; Canbeck, B [Lund University, Sweden; Cohen, D [UMR, France; Courty, PE [UMR, France; Coutinho, PM [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Danchin, E [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Delaruelle, C [UMR, France; Detter, J C [U.S. Department of Energy, Joint Genome Institute; Deveau, A [UMR, France; DiFazio, Stephen P [West Virginia University; Duplessis, S [UMR, France; Fraissinet-Tachet, L [Universite de Lyon, France; Lucic, E [UMR, France; Frey-Klett, P [UMR, France; Fourrey, C [UMR, France; Feussner, I [Georg-August Universitat Gottingen Germany; Gay, G [Universite de Lyon, France; Grimwood, Jane [Stanford University; Hoegger, P J [Georg-August Universitat Gottingen Germany; Jain, P [University of Alabama, Huntsville; Kilaru, S [Georg-August Universitat Gottingen Germany; Labbe, J [UMR, France; Lin, Y C [Ghent University, Belgium; Legue, V [UMR, France; Le Tacon, F [UMR, France; Marmeisse, R [Universite de Lyon, France; Melayah, D [Universite de Lyon, France; Montanini, B [UMR, France; Muratet, M [University of Alabama, Huntsville; Nehls, U [Eberhard-Karls-Universitat, Tubingen, Germany; Niculita-Hirzel, H [University of Lausanne, Switzerland; Oudot-Le Secq, M P [UMR, France; Peter, M [UMR, France; Quesneville, H [Unite de Recherches en Genomique-Info,Evry Cedex; Rajashekar, B [Lund University, Sweden; Reich, M [UMR, France; Rouhler, N [UMR, France; Schmutz, Jeremy [Stanford University; Yin, Tongming [ORNL; Chalot, M [UMR, France; Henrissat, B [Architecture et Fonction des Macromolecules Biologiques, UMR 6098 CNRS and Unive; Kues, U [Georg-August Universitat Gottingen Germany; Lucas, S [U.S. Department of Energy, Joint Genome Institute; Van de Peer, Y [Ghent University, Belgium; Podila, G [University of Alabama, Huntsville; Polle, A [Georg-August Universitat Gottingen Germany; Pukkila, P J [University of North Carolina, Chapel Hill; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Rouze, P [Ghent University, Belgium; Sanders, I R [University of Lausanne, Switzerland; Stajich, J E [University of California, Berkeley; Tunlid, A [Lund University, Sweden; Tuskan, Gerald A [ORNL; Grigoriev, I. [U.S. Department of Energy, Joint Genome Institute

    2008-01-01

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants1,2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and

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

    Science.gov (United States)

    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 mycorrhizal fungus, however, stimulated all growth parameters of the treated plant comparing to non-mycorrhizal treated plant. The photosynthetic pigments (carotene in flowers and chlorophylls a and b in leaves) were also stimulated by the mycorrhizal fungi of well-watered as well as of water-stressed plants. The total pigments of mycorrhizal plants grown under well-watered conditions were higher than those of non-mycorrhizal ones by 60%. In most cases, drought-stressed mycorrhizal plants were significantly better than those of the non-mycorrhizal plants. So, the overall results suggest that mycorrhizal fungal colonization affects host plant positively on growth, pigments, and phosphorous content, flower quality and thereby alleviates the stress imposed by water with holding. PMID:23961109

  14. Utilisation of carbon substrates by orchid and ericoid mycorrhizal fungi from Australian dry sclerophyll forests.

    Science.gov (United States)

    Midgley, David J; Jordan, Lyndon A; Saleeba, Jennifer A; McGee, Peter A

    2006-05-01

    The utilisation of a range of cell-wall-related and aromatic carbon substrates by multiple genotypes of three ericoid mycorrhizal fungal taxa was compared with two orchid mycorrhizal fungal taxa. Both groups of fungi catabolised most common substrates, though significant inter- and intraspecific variability was observed in the use of a few carbon substrates. Orchid mycorrhizal fungi had limited access to tannic acid as a carbon source and did not use phenylalanine, while the ericoid mycorrhizal fungi used both. Utilisation of tryptophan was limited to single genotypes of each of the orchid mycorrhizal fungi, and to only two of the three ericoid mycorrhizal fungi examined. Although broadly similar, some significant differences apparently exist in carbon catabolism of ericoid and orchid mycorrhizal fungi from the same habitat. Functional and ecological implications of these observations are discussed.

  15. From extensive clone libraries to comprehensive DNA arrays for the efficient and simultaneous detection and identification of orchid mycorrhizal fungi.

    Science.gov (United States)

    Lievens, Bart; van Kerckhove, Stefan; Justé, Annelies; Cammue, Bruno P A; Honnay, Olivier; Jacquemyn, Hans

    2010-01-01

    A DNA array was developed from extensive clone library sequence data sets for the assessment of dominant members of mycorrhizal fungi that associate with terrestrial orchid species. As a-proof-of-concept, the array was developed for the basidiomycetous mycorrhizal partners from three closely related perennial Orchis species, including Orchis anthropophora, O. militaris and O. purpurea. Based on internal transcribed spacer regions, oligonucleotides were developed for seven operational taxonomic units (OTUs; defined as groups of sequences sharing at least 97% sequence similarity), corresponding to members of the Tulasnellaceae family. In order to cover a broader spectrum of tulasnelloid fungi, oligonucleotides were as well developed for two subsets of closely related OTUs. The array was evaluated using multiple primer pairs. In addition, hybridization results were validated by recovery and sequencing of the hybridized amplicons as well as by hybridizing reference DNA samples. Considering the unlimited expansion possibilities of DNA arrays to include specific detector oligonucleotides for other and more microorganisms, the method described here has the major advantage that it provides a powerful, rapid and cost-effective way for the simultaneous detection and identification of a wide range of orchid mycorrhizae. The design, development and advantages of the array are discussed in relation to its potential for future research in mycorrhizal ecology. Copyright 2009 Elsevier B.V. All rights reserved.

  16. 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

    Virus-induced gene silencing (VIGS) is an alternative reverse genetics tool for silencing of genes in some plants, which are difficult to transform. The pea early-browning virus (PEBV) has been developed as a VIGS vector and used in pea for functional analysis of several genes. However......, 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...

  17. Multiple control levels of root system remodeling in arbuscular mycorrhizal symbiosis

    Directory of Open Access Journals (Sweden)

    Uta ePaszkowski

    2013-06-01

    Full Text Available In nature the root systems of most plants develop intimate symbioses with Glomeromycotan fungi that assist in the acquisition of mineral nutrients and water through uptake from the soil and direct delivery into the root cortex. Root systems are endowed with a strong, environment-responsive architectural plasticity that also manifests itself during the establishment of arbuscular mycorrhizal (AM symbioses, predominantly in lateral root proliferation. In this review we collect evidence for the idea that AM induced root system remodeling is regulated at several levels: by AM fungal signaling molecules and by changes in plant nutrient status and distribution within the root system.

  18. P depletion and activity of phosphatases in the rhizosphere of mycorrhizal and non-mycorrhizal cucumber (Cucumis Sativus L.)

    DEFF Research Database (Denmark)

    Joner, E.J.; Magid, J.; Gahoonia, T.S.

    1995-01-01

    was sectioned in a freezing microtome and analyzed for extracellular acid (pH 5.2) and alkaline (pH 8.5) phosphatase activity as well as depletion of NaHCO-3-extractable inorganic P (P-i) and P-o. Roots and mycorrhizal hyphae depleted the soil of P-i but did not influence the concentration of P-o in spite...... of increased phosphatase activity in soil influenced by roots. Phosphatase activity at both pH values was highest in soil influenced by uncolonized roots, but this was attributed to higher root length densities as compared to mycorrhizal roots. Mycorrhizal hyphae showed no influence on soil phosphatase...... activity in spite of high hyphal length densities ( gt 22 m cm-3). Hyphae were also able to deplete soil of P-i beyond the membrane interface....

  19. Common mycorrhizal networks and their effect on the bargaining power of the fungal partner in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Bücking, Heike; Mensah, Jerry A; Fellbaum, Carl R

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi form mutualistic interactions with the majority of land plants, including some of the most important crop species. The fungus takes up nutrients from the soil, and transfers these nutrients to the mycorrhizal interface in the root, where these nutrients are exchanged against carbon from the host. AM fungi form extensive hyphal networks in the soil and connect with their network multiple host plants. These common mycorrhizal networks (CMNs) play a critical role in the long-distance transport of nutrients through soil ecosystems and allow the exchange of signals between the interconnected plants. CMNs affect the survival, fitness, and competitiveness of the fungal and plant species that interact via these networks, but how the resource transport within these CMNs is controlled is largely unknown. We discuss the significance of CMNs for plant communities and for the bargaining power of the fungal partner in the AM symbiosis.

  20. Ecto- and arbuscular mycorrhizal symbiosis can induce tolerance to toxic pulses of phosphorus in jarrah (Eucalyptus marginata) seedlings

    OpenAIRE

    Kariman, Khalil; Barker, Susan J.; Finnegan, Patrick M.; Tibbett, Mark

    2014-01-01

    In common with many plants native to low P soils, jarrah (Eucalyptus marginata) develops toxicity symptoms upon exposure to elevated phosphorus (P). Jarrah plants can establish arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations, along with a non-colonizing symbiosis described recently. AM colonization is known to influence the pattern of expression of genes required for P uptake of host plants and our aim was to investigate this phenomenon in relation to P sensitivity. Therefo...

  1. Can NPK fertilizers enhance seedling growth and mycorrhizal status of Tuber melanosporum-inoculated Quercus ilex seedlings?

    Science.gov (United States)

    Suz, Laura M; Martín, María P; Fischer, Christine R; Bonet, José A; Colinas, Carlos

    2010-06-01

    Although successful cultivation of the black truffle (Tuber melanosporum) has inspired the establishment of widespread truffle orchards in agricultural lands throughout the world, there are many unknowns involved in proper management of orchards during the 6-10 years prior to truffle production, and there are conflicting results reported for fertilizer treatments. Here, we systematically evaluate the combined effects of nitrogen, phosphorous, and potassium with different doses of each element, applied to either foliage or roots, on plant growth parameters and the mycorrhizal status of outplanted 3-year-old seedlings in five experimental Quercus ilex-T. melanosporum orchards. Fertilization did not significantly improve seedling aboveground growth, but the plants treated with the fertilizer 12-7-7 applied to the roots (HNr) displayed longer field-developed roots. Only the fertilizer with the highest dose of K (10-6-28) applied to the foliage (HKf) increased the probability of fine root tip colonization by T. melanosporum in field-developed roots. However, the plants treated with the same fertilizer applied to the soil (HKr) presented the highest probability for colonization by other competing mycorrhizal soil fungi. Potassium seems to have an important role in mycorrhizal development in these soils. Apart from T. melanosporum, we found 14 ectomycorrhizal morphotypes, from which seven were identified to species level, three to genus, two to family, and two remained unidentified by their morphological characteristics and DNA analyses.

  2. Life histories of symbiotic rhizobia and mycorrhizal fungi. Review.

    NARCIS (Netherlands)

    Denison, R.F.; Kiers, E.T.

    2011-01-01

    Research on life history strategies of microbial symbionts is key to understanding the evolution of cooperation with hosts, but also their survival between hosts. Rhizobia are soil bacteria known for fixing nitrogen inside legume root nodules. Arbuscular mycorrhizal (AM) fungi are ubiquitous root

  3. (Vigna radiata L.) with arbuscular mycorrhizal fungi a

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... cultivar, rhizobial strains, and environmental conditions. (Giller, 2001). Mungbean can also establish symbiosis with arbuscular mycorrhizal fungi (AMF) (Clarkson, 1985; ..... Planta, 201: 463-469. Drevon JJ, Heckmann MO, Soussana JF, Salsac L (1988). Inhibition of nitrogen fixation by nitrate assimilation in ...

  4. Mycorrhizal association in soybean and weeds in competition

    Directory of Open Access Journals (Sweden)

    Cíntia Maria Teixeira Fialho

    2016-04-01

    Full Text Available The purpose of this study was to evaluate the effects of mycorrhizal association on the interference of Bidens pilosa, Urochloa decumbens and Eleusine indica on soybean culture in two conditions: a plants competing without contact with roots of another species; b with contact between roots. At 60 days after planting, growth, nutrient accumulation and mycorrhizal colonization of soybean and weeds were evaluated. The contact between roots of soybean plant and weed species increased the negative interference effects for both species, with less growth and nutrient accumulation. With the individualization of roots, higher competition occurred for soil resources up to 60 days of coexistence between species. In competition with soybean, Bidens pilosa and Urochloa decumbens stood out in accumulation of most nutrients without differing from when cultivated in monocultivation. The increase of the soybean mycorrhizal colonization was 53, 40 and 33% when in competition with Urochloa decumbens, Eleusine indica and Bidens pilosa species, respectively. A positive interaction occurred for soybean mycorrhizal colonization and competing plants irrespective of weed species or root contact.

  5. Siderophore production by mycorrhizal sorghum roots under micronutrient deficient condition

    Directory of Open Access Journals (Sweden)

    N. Aliasgharzad

    2009-05-01

    Full Text Available It has widely been accepted that mycorrhizal symbiosis improves micronutrients uptake by most of the plants. In this study, sorghum (Sorghum bicolor L. plants were grown in sterile perlite and were inoculated with either Glomus etunicatum (GE or G.intraradices (GI, while the control set was left un-inoculated. Rorison's nutrient solution with three levels of 0, half and full strength (C0, C0.5 and C1, respectively of Fe, Cu, Zn and Mn was applied to the pots during 85 days of growth period. Chrome azurol-S assay was used for determination of siderophores in root leachates on 45, 65 and 85 days after sowing (DAS. Siderophore production per unit volume of root was higher in mycorrhizal than non-mycorrhizal plants. Both GE and GI were efficient fungi in this respect. Siderophore production was significantly induced at C0 level of the micronutrients. Amount of siderophores produced on 45 and 85 DAS was more than 65 DAS. Mycorrhizal root colonization by GE or GI was not significantly affected by micronutrient levels.

  6. In vitro culture of arbuscular mycorrhizal fungi: advances and future ...

    African Journals Online (AJOL)

    Arbuscular mycorrhizal (AM) fungi are ecologically important for most vascular plants for their growth and survival. AM fungi are obligate symbionts. In recent years, there have been many attempts to cultivate in vitro. Some relevant results indicate efforts are not far from successful growth of AM fungi independent of a plant ...

  7. A biological market analysis of the plant-mycorrhizal symbiosis

    NARCIS (Netherlands)

    Wyatt, G.A.K.; Kiers, E.T.; Gardner, A.; West, S.A.

    2014-01-01

    It has been argued that cooperative behavior in the plant-mycorrhizal mutualism resembles trade in a market economy and can be understood using economic tools. Here, we assess the validity of this "biological market" analogy by investigating whether a market mechanism-that is, competition between

  8. In vitro culture of arbuscular mycorrhizal fungi: advances and future ...

    African Journals Online (AJOL)

    Admin

    This paper describes the methods to cultivate root organs, and to select and purify AM fungal inocula (intraradical ... Key words: Arbuscular mycorrhizal fungi, continuous culture, root organ cultures, intraradical and extraradical forms, in vitro. .... Although in vitro culture is an artificial system, it may be a valuable tool to study ...

  9. Effect of arbuscular mycorrhizal fungal inoculation on growth, and ...

    African Journals Online (AJOL)

    FAMA

    2015-09-30

    Sep 30, 2015 ... architecture and low root hair density (warm season C4 grasses), derive the greater growth benefits from AMF ... fine root architecture is considered as an alternative to mycorrhizae in P-limited soils. ..... L. to mycorrhizal fungi, phosphorus and soil organic matter: implications for reclamation. J. Appl. Ecol.

  10. Mycorrhizal specificity in the fully mycoheterotrophic Hexalectris Raf. (Orchidaceae: Epidendroideae)

    Science.gov (United States)

    Aaron H. Kennedy; D. Lee Taylor; Linda E. Watson

    2011-01-01

    Mycoheterotrophic species have abandoned an autotrophic lifestyle and obtain carbon exclusively from mycorrhizal fungi. Although these species have evolved independently in many plant families, such events have occurred most often in the Orchidaceae, resulting in the highest concentration of these species in the tracheophytes. Studies of mycoheterotrophic species...

  11. Mycorrhizal association of some agroforestry tree species in two ...

    African Journals Online (AJOL)

    Administrator

    2011-05-05

    May 5, 2011 ... Mycorrhizal colonization of different agroforestry tree species in two social forestry nurseries was investigated. Percentage of Arbuscular ... collected from two social forestry nurseries of Mahabubnagar district (A.P), and brought to the .... main regression line is shown in red. Spores of the lower infection ...

  12. Do chlorophyllous orchids heterotrophically use mycorrhizal fungal carbon?

    Science.gov (United States)

    Selosse, Marc-André; Martos, Florent

    2014-11-01

    The roots of orchids associate with mycorrhizal fungi, the rhizoctonias, which are considered to exchange mineral nutrients against plant carbon. The recent discovery that rhizoctonias grow endophytically in non-orchid plants raises the possibility that they provide carbon to orchids, explaining why some orchids differ in isotopic abundances from autotrophic plants.

  13. Mycorrhizal status and AMF community structure of fruit crops from ...

    African Journals Online (AJOL)

    Arbuscular mycorrhizal fungi (AMF) association of Mangifera indica (mango), Musa acuminate (banana), Carica papaya (papaya), Citrus limon (lemon), Persea americana (avocado), and Psidium guajava (guava) was investigated from a lowland area of Showa Robit. Percentage of root colonization, spore abundance, ...

  14. Effect of mycorrhizal inoculum and urea fertilizer on diseases ...

    African Journals Online (AJOL)

    A randomized block design with four replicates was used, with two applications of mycorrhizal inoculum. The inoculum contained spores of Glomus sp. and Gigaspora sp. in concentration of 2.103 spores.g-¹. A urea treatment and an absolute control were also used. The number of nodules per plant, the root colonization rate ...

  15. Arsenic uptake and phytoremediation potential by arbuscular mycorrhizal fungi

    Science.gov (United States)

    Xinhua He; Erik Lilleskov

    2014-01-01

    Arsenic (As) contamination of soils and water is a global problem because of its impacts on ecosystems and human health. Various approaches have been attempted for As remediation, with limited success. Arbuscular mycorrhizal (AM) fungi play vital roles in the uptake of water and essential nutrients, especially phosphorus (P), and hence enhance plant performance and...

  16. Interactive effects of Arbuscular mycorrhizal fungi and rhizobial ...

    African Journals Online (AJOL)

    Legumes form a tripartite symbiosis with Arbuscular mycorrhizal fungi (AMF) and rhizobia. Chickpea plants were inoculated with six strains of Mesorhizobium ciceri and three AMF species, Glomus intraradices (GI), G. mosseae (GM) and G. etunicatum (GE). The plants inoculated with a number of AMF species and bacterial ...

  17. Cropping enhances mycorrhizal benefits to maize in a tropical soil

    Czech Academy of Sciences Publication Activity Database

    Jemo, M.; Souleymanou, A.; Frossard, E.; Jansa, Jan

    2014-01-01

    Roč. 79, č. 2014 (2014), s. 117-124 ISSN 0038-0717 R&D Projects: GA MŠk(CZ) LK11224; GA ČR GAP504/12/1665 Institutional support: RVO:61388971 Keywords : tropical soil * mycorrhizal benefits * southern Cameroon Subject RIV: EE - Microbiology, Virology Impact factor: 3.932, year: 2014

  18. Mycorrhizal status of Lycium europaeum in the coastal dunes of ...

    African Journals Online (AJOL)

    SARAH

    2013-11-30

    Nov 30, 2013 ... of L. europaeum and determines its presence in different regions of Morocco. The role of mycorrhizal fungi in the growth and the nutrition of plants have been amply demonstrated by. Chaussod and Nouaim (1996). For example, arbuscular mycorrhizae, improve the ability of the plant nutrition, including ...

  19. Shoot- and root-borne cytokinin influences arbuscular mycorrhizal symbiosis

    NARCIS (Netherlands)

    Rebeca Cosme, M.P.

    2016-01-01

    The arbuscular mycorrhizal (AM) symbiosis is functionally important for the nutrition and growth of most terrestrial plants. Nearly all phytohormones are employed by plants to regulate the symbiosis with AM fungi, but the regulatory role of cytokinin (CK) is not well understood. Here, we used

  20. Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Coffea ...

    African Journals Online (AJOL)

    SARAH

    2013-04-25

    Apr 25, 2013 ... symbiosis to plant drought tolerance is the result of accumulative physical, nutritional, physiological and cellular effects. Mycorrhizal fungi, which are active in the rhizosphere, take part in the cycles and transfer of mineral elements in the soil and into the roots (George et al., 1992). Some minerals such as ...

  1. Effect of mycorrhizal inoculum and urea fertilizer on diseases ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... Diseases (rosette virus disease (RVD), Cercospora leaf spot (CLS) and poverty of soils in nutrients are ... Healthy plants infected plants. Figure 1. Effect of mycorrhizae and urea fertilizer on nodulation of groundnut crops 7 weeks after inoculation. .... between mycorrhizal fungi and the plants results in the.

  2. Contribution of arbuscular mycorrhizal fungi to pearl millet ...

    African Journals Online (AJOL)

    Land degradation may cause nutrient deficiencies for plant growth. These deficiencies can be partly compensated through plant association with arbuscular mycorrhizal (AM) fungi under the condition that the degradation status does not affect the symbiosis. We therefore investigated P and K uptake by millet [Pennisetum ...

  3. Mycorrhizal status of Olea europaea spp. oleaster in Morocco

    African Journals Online (AJOL)

    SARAH

    2013-01-31

    Jan 31, 2013 ... rhizosphere of the oleaster trees, revealed the presence of five fungus species: Glomus intraradices, ... Mycorrhizal fungi are an essential link between soil and plants. They play an important role in the dynamic of the ecosystem (Bever et al., 1997, van ... plants by providing a particular mineral nutrition.

  4. Arbuscular mycorrhizal fungi improve the growth of olive trees and ...

    African Journals Online (AJOL)

    Arbuscular mycorrhizal fungi improve the growth of olive trees and their resistance to transplantation stress. ... This change in the root: shoot ratio permitted greater utilization of soil resources and strengthened the plant's capacity to resist transplantation shock and water stress. The abundance of the two fungi in the roots of ...

  5. Solanum cultivar responses to arbuscular mycorrhizal fungi: growth ...

    African Journals Online (AJOL)

    A greenhouse experiment was carried out in a sandy soil with a low available phosphorus to evaluate responsiveness of four Solanum aethiopicum cultivars to indigenous arbuscular mycorrhizal fungi. Results showed clear interaction between genetic variability of cultivars and fungal isolates on shoot biomass and on ...

  6. The effects of arbuscular mycorrhizal fungi and phosphorus levels ...

    African Journals Online (AJOL)

    user

    2015-01-21

    Jan 21, 2015 ... To evaluate the effect of arbuscular mycorrhizal fungi and phosphorus levels on root traits of cucumber plants, a factorial experiment was carried out based on a randomized completely design pot culture. Four phosphorus fertilization treatments, including 2, 5, 10 and 15 mg P kg-1 soil possessed ...

  7. Effects of arbuscular mycorrhizal fungi on resistance to Phytophthora ...

    African Journals Online (AJOL)

    Thai honey tangerine (Sainamphueng tangerine) is generally grown by grafting on rootstocks of another variety of tangerine or citrus species which may differ in their reaction to beneficial and pathogenic soil organisms. The objectives of this study were to evaluate responses to arbuscular mycorrhizal (AM) fungi and ...

  8. Growth and mineral nutrition responses of mycorrhizal and non ...

    African Journals Online (AJOL)

    The effects of a superphosphate (SP) and a rock phosphate (RP), with equal total P contents, on the growth and mineral nutrition responses of mycorrhizal and nonmycorrhizal cowpea, pigeon pea and groundnut were investigated in a pot experiment using an air-dry gamma ray-sterilized (1.5Mrad) Andisol subsoil.

  9. Influence of mycorrhizal inoculation on alley cropped farms in a ...

    African Journals Online (AJOL)

    The use of Arbuscular mycorrhizal (AM) fungi under farmers' conditions was tried at Ajibode Village, a humid tropical environment on maize/cassava intercropped farms in an alley cropping system. Four species of AM fungi (Glomus clarum, Glomus mosseae Glomus etunicatum and Acaulospora dilatata) were used in ...

  10. Arbuscular mycorrhizal fungi species associated with rhizosphere of ...

    African Journals Online (AJOL)

    A survey of arbuscular mycorrhizal fungi (AMF) diversity and date palm (Phoenix dactylifera L.) tree root colonization in arid areas was undertaken in ten palm groves located along the Ziz valley (Tafilalet, south-west Morocco). The frequency and the mean intensity of root colonization reached 72 and 43% respectively and ...

  11. Arbuscular-mycorrhizal fungi (Glomales) in Egypt. III: Distribution ...

    African Journals Online (AJOL)

    Roots and rhizospheric soils of 26 plant species belonging to 18 families representing five different habitats at El-Omayed Biosphere Reserve were collected and examined for arbuscular-mycorrhizal fungal (AMF) associations. Plant species recorded in the habitat of coastal sand dunes had the highest percentage of ...

  12. Transgenerational effects of plant sex and arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Varga, Sandra; Vega-Frutis, Rocío; Kytöviita, Minna-Maarit

    2013-08-01

    In gynodioecious plants, females are predicted to produce more and/or better offspring than hermaphrodites in order to be maintained in the same population. In the field, the roots of both sexes are usually colonized by arbuscular mycorrhizal (AM) fungi. Transgenerational effects of mycorrhizal symbiosis are largely unknown, although theoretically expected. We examined the maternal and paternal effects of AM fungal symbiosis and host sex on seed production and posterior seedling performance in Geranium sylvaticum, a gynodioecious plant. We hand-pollinated cloned females and hermaphrodites in symbiosis with AM fungi or in nonmycorrhizal conditions and measured seed number and mass, and seedling survival and growth in a glasshouse experiment. Females produced more seeds than hermaphrodites, but the seeds did not germinate, survive or grow better. Mycorrhizal plants were larger, but did not produce more seeds than nonmycorrhizal plants. Transgenerational parental effects of AM fungi were verified in seedling performance. This is the first study to show transgenerational mycorrhiza-mediated parental effects in a gynodioecious species. Mycorrhizal symbiosis affects plant fitness mainly through female functions with enduring effects on the next generation. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  13. Phenanthrene uptake by Medicago sativa L. under the influence of an arbuscular mycorrhizal fungus

    Energy Technology Data Exchange (ETDEWEB)

    Wu Naiying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Department of Chemistry, Shangqiu Normal College, Shangqiu 476000 (China); Huang Honglin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhang Shuzhen, E-mail: szzhang@rcees.ac.c [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Zhu Yongguan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085 (China); Christie, Peter [Agri-Environment Branch, Agriculture Food and Environmental Science Division, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom); Zhang Yong [State Key Laboratory of Marine Environmental Science, Environmental Science Research Centre, Xiamen University, Xiamen 361005 (China)

    2009-05-15

    Phenanthrene uptake by Medicago sativa L. was investigated under the influence of an arbuscular mycorrhizal fungus. Inoculation of lucerne with the arbuscular mycorrhizal fungus Glomus etunicatum L. resulted in higher phenanthrene accumulation in the roots and lower accumulation in the shoots compared to non-mycorrhizal controls. Studies on sorption and desorption of phenanthrene by roots and characterization of heterogeneity of mycorrhizal and non-mycorrhizal roots using solid-state {sup 13}C nuclear magnetic resonance spectroscopy ({sup 13}C NMR) demonstrated that increased aromatic components due to mycorrhizal inoculation resulted in enhanced phenanthrene uptake by the roots but lower translocation to the shoots. Direct visualization using two-photon excitation microscopy (TPEM) revealed higher phenanthrene accumulation in epidermal cells of roots and lower transport into the root interior and stem in mycorrhizal plants than in non-mycorrhizal controls. These results provide some insight into the mechanisms by which arbuscular mycorrhizal inoculation may influence the uptake of organic contaminants by plants. - Colonization by an arbuscular mycorrhizal fungus promoted root uptake and decreased shoot uptake of phenanthrene by Medicago sativa L.

  14. Plant mycorrhizal traits in Europe in relation to climatic and edaphic gradients

    Science.gov (United States)

    Guillermo Bueno, C.; Gerz, Maret; Zobel, Martin; Moora, Mari

    2017-04-01

    Around 90% of plant species associate with mycorrhizal fungi. The symbiosis is known to provide plants with soil N, P and water, and fungi with plant photosynthesized carbohydrates. However, not all mycorrhizal symbioses are identical. The identity of associated plant and fungal species differs, as does the effect of the symbiosis on nutrient cycling and ecosystems more generally. In this study, we analysed the European distribution of two plant mycorrhizal traits in relation to climatic and edaphic drivers. We used the European distribution of the frequency of mycorrhizal colonization (plant mycorrhizal status); whether mycorrhizal fungi either always (obligately mycorrhizal, OM), or sometimes (facultatively mycorrhizal, FM) colonize plant roots, and the four main plant mycorrhizal types; arbuscular (AM), ecto-(ECM), ericoid (ERM), and non-mycorrhizal (NM) plants. We expected AM species to predominate in ecosystems where most soil nutrients occur in inorganic forms (lower latitudes) and those with higher soil pH. By contrast, due to the saprophytic abilities of ECM and ERM fungi, we expected ECM and ERM plants to predominate in ecosystems where nutrients are bound to organic compounds (higher latitudes) and those with lower soil pH. NM plant species are known to be common in disturbed habitats or in extremely phosphorus poor ecosystems, such as the Arctic tundra. Our results showed that the distribution of mycorrhizal types was driven by temperature and soil pH, with increases of NM, ECM and ERM, and decreases of AM, with latitude. FM predominated over OM species and this difference increased with latitude and was dependent on temperature drivers only. These results represent the first evidence at a European scale of plant mycorrhizal distribution patterns linked with climatic and edaphic gradients, supporting the idea of a tight relationship between the mycorrhizal symbiosis and nutrient cycling.

  15. 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

  16. Mycorrhizal compatibility and symbiotic seed germination of orchids from the Coastal Range and Andes in south central Chile.

    Science.gov (United States)

    Herrera, Hector; Valadares, Rafael; Contreras, Domingo; Bashan, Yoav; Arriagada, Cesar

    2017-04-01

    Little is known about Orchidaceae plants in Chile and their mycorrhizal associations, a key issue for designing protective actions for endangered species. We investigated root fungi from seven terrestrial orchid species to identify potential mycorrhizal fungi. The main characteristics of Rhizoctonia-like fungi were observed under light microscopy, and isolates were identified through PCR-ITS sequencing. Molecular identification of fungal sequences showed a high diversity of fungi colonizing roots. Fungal ability to germinate seeds of different orchids was determined in symbiotic germination tests; 24 fungal groups were isolated, belonging to the genera Tulasnella, Ceratobasidium, and Thanatephorus. Furthermore, dark septate and other endophytic fungi were identified. The high number of Rhizoctonia-like fungi obtained from adult orchids from the Coastal mountain range suggests that, after germination, these orchids may complement their nutritional demands through mycoheterotrophy. Nonetheless, beneficial associations with other endophytic fungi may also co-exist. In this study, isolated mycorrhizal fungi had the ability to induce seed germination at different efficiencies and with low specificity. Germin ation rates were low, but protocorms continued to develop for 60 days. A Tulasnella sp. isolated from Chloraea gavilu was most effective to induce seed germination of different species. The dark septate endophytic (DSE) fungi did not show any effect on seed development; however, their widespread occurrence in some orchids suggests a putative role in plant establishment.

  17. 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.

  18. Quantity and distribution of arbuscular mycorrhizal fungal storage organs within dead roots.

    Science.gov (United States)

    Müller, Anja; Ngwene, Benard; Peiter, Edgar; George, Eckhard

    2017-04-01

    The formation of storage organs, such as spores and vesicles, is a central part of the life cycle of an arbuscular mycorrhizal fungus (AMF), but the conditions under which this occurs in AMF are not well understood. Here, quantity and distribution of storage organs formed by the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae within dead (excised) roots were characterised. 'Trap roots' (TR), separated from the growth substrate by a 30-μm mesh, supported hyphal growth and formation of storage organs of the AMF. Hyphae developed both inside and on the outside of the TR and also within air gaps of surrounding nylon mesh compartments, but formation of vesicles and spores was confined to the interior and to the surface of the TR. Up to 20 % of the TR length harboured newly formed storage organs, resulting in a number of about 60 per mg TR dry weight. The portion of TR length containing storage organs was greater in coarse (diameter >300 μm) than in thin (storage organs within dead roots in preference to air space in the substrate. Dead roots may indirectly supply nutrients to AMF (once they have been mineralised) or represent a protected space for the fungal structures to develop. The experimental technique described here allows for the preparation of AMF spores and vesicles of F. mosseae free of any mineral substrate.

  19. SOURCES OF MYCORRHIZAL INFECTION OF SHOREA ACUMINATA SEEDLINGS UNDER LABORATORY CONDITIONS

    Directory of Open Access Journals (Sweden)

    LEE Su SEE

    1995-01-01

    Full Text Available Uninoculated dipterocarp seedlings raised in normal field soil in nurseries were always found to have mycorrhizas after a few months. This study set out to determine whether dipterocarp seedlings could continue to grow and develop in the absence of mycorrhizas and also to determine possible sources of mycorrhizal infection of dipterocarp seedlings raised under laboratory conditions using Shorea acuminata as a typical example. Seedlings were planted in capped or uncapped perspex boxes containing sterile or non-sterile field soil and watered daily with sterile water or tap water. Seedling growth and development of mycorrhizas were monitored at monthly intervals for up to seven months. Seedlings grown in sterile soil remained uninfected after seven months while infection was found in some of the seedlings grown in normal soil regardless of whether they had been watered with tap water or sterile water. This showed that field soil (i.e. under grass far from the forest contained suitable inoculum for forest tree seedlings. Tap water and the air were not important sources of infection. However, mycorrhizal infection was very uneven indicating that the inoculum was probably very unevenly distributed in the soil or that the inoculum density was rather low. Seedlings grown in sterile soil showed better growth than those grown in normal soil and infection of roots by parasitic fungi in the latter was also observed.

  20. 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.

  1. Ecto- and arbuscular mycorrhizal symbiosis can induce tolerance to toxic pulses of phosphorus in jarrah (Eucalyptus marginata) seedlings.

    Science.gov (United States)

    Kariman, Khalil; Barker, Susan J; Finnegan, Patrick M; Tibbett, Mark

    2014-10-01

    In common with many plants native to low P soils, jarrah (Eucalyptus marginata) develops toxicity symptoms upon exposure to elevated phosphorus (P). Jarrah plants can establish arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations, along with a non-colonizing symbiosis described recently. AM colonization is known to influence the pattern of expression of genes required for P uptake of host plants and our aim was to investigate this phenomenon in relation to P sensitivity. Therefore, we examined the effect on hosts of the presence of AM and ECM fungi in combination with toxic pulses of P and assessed possible correlations between the induced tolerance and the shoot P concentration. The P transport dynamics of AM (Rhizophagus irregularis and Scutellospora calospora), ECM (Scleroderma sp.), non-colonizing symbiosis (Austroboletus occidentalis), dual mycorrhizal (R. irregularis and Scleroderma sp.), and non-mycorrhizal (NM) seedlings were monitored following two pulses of P. The ECM and A. occidentalis associations significantly enhanced the shoot P content of jarrah plants growing under P-deficient conditions. In addition, S. calospora, A. occidentalis, and Scleroderma sp. all stimulated plant growth significantly. All inoculated plants had significantly lower phytotoxicity symptoms compared to NM controls 7 days after addition of an elevated P dose (30 mg P kg(-1) soil). Following exposure to toxicity-inducing levels of P, the shoot P concentration was significantly lower in R. irregularis-inoculated and dually inoculated plants compared to NM controls. Although all inoculated plants had reduced toxicity symptoms and there was a positive linear relationship between rank and shoot P concentration, the protective effect was not necessarily explained by the type of fungal association or the extent of mycorrhizal colonization.

  2. Possible involvement of hyphal phosphatase in phosphate efflux from intraradical hyphae isolated from mycorrhizal roots colonized by Gigaspora margarita.

    Science.gov (United States)

    Kojima, Tomoko; Saito, Masanori

    2004-06-01

    We developed a method for separating physiologically active intraradical hyphae of arbuscular mycorrhizal (AM) fungi from mycorrhizal roots, allowing the hyphae to be used for physiological and biochemical experiments. In the present study, the phosphate efflux from the intraradical hyphae in vitro was examined in relation to hyphal phosphatase activity. Onion seedlings (Allium cepa) were planted in the soil inoculated with Gigaspora margarita. Six weeks after transplanting, the intraradical hyphae were isolated from the mycorrhizal roots using plant cell-wall digestion enzymes. The hyphae were incubated briefly at 25 degrees C in a buffer solution (50 mM Tris/HCl, pH 7.4), then incubated for 2 h and gently shaken with various inhibitors. Phosphate efflux, the amount of phosphate released to the buffer, was analysed by EnzChek phosphate assay kit. Hyphal phosphatase activity was stained histochemically and the proportion of phosphatase-active arbuscules was examined for each inhibitor. Phosphate effluxes were to some degree reduced by all inhibitors used, while the phosphatase inhibitor, BeSO4, greatly reduced the efflux. The degree of inhibition in the arbuscular phosphatase by each chemical was closely correlated to the decrease in the phosphate efflux. These results suggest that hyphal phosphatase may be partially involved in the phosphate efflux process from intraradical hyphae.

  3. 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.

  4. Mid-Infrared and near-infrared spectral properties of mycorrhizal and non-mycorrhizal root cultures.

    Science.gov (United States)

    Calderón, Francisco J; Acosta-Martinez, Veronica; Douds, David D; Reeves, James B; Vigil, Merle F

    2009-05-01

    We investigated the Fourier-transformed mid-infrared (MIR) and near-infrared (NIR) spectroscopic properties of mycorrhizal (M) and non-mycorrhizal (NM) carrot roots with the goal of finding infrared markers for colonization by arbuscular mycorrhizal (AM) fungi. The roots were cultured with or without the AM fungus Glomus intraradices under laboratory conditions. A total of 50 M and NM samples were produced after pooling subsamples. The roots were dried, ground, and scanned separately for the NIR and MIR analyses. The root samples were analyzed for fatty acid composition in order to confirm mycorrhizal infection and to determine the presence of fatty acid markers. Besides the roots, fatty acid standards, pure cultures of saprophytic fungi, and chitin were also scanned in order to identify spectral bands likely to be found in M samples. Principal components analysis (PCA) was used to illustrate spectral differences between the M and NM root samples. The NIR analysis achieved good resolution with the raw spectral data and no pretreatment was needed to obtain good resolution in the PCA analysis of the NIR data. Standard normal variate and detrending pretreatment improved the resolution between M and NM in the MIR range. The PCA loadings and/or the spectral subtraction of selected samples showed that M roots are characterized by absorbances at or close to 400 cm(-1), 1100-1170 cm(-1), 1690 cm(-1), 2928 cm(-1), and 5032 cm(-1). The NM samples had characteristic absorbances at or near 1734 cm(-1), 3500 cm(-1), 4000 cm(-1), 4389 cm(-1), and 4730 cm(-1). Some of the bands that differentiate M from NM roots are prominent in the spectra of pure fungal cultures, chitin, and fatty acids. Our results show that mycorrhizal and nonmycorrhizal root tissues can be differentiated via MIR and NIR spectra with the advantage that the same samples can then be used for other analyses.

  5. Response of Mycorrhizal Diversity to Current Climatic Changes

    Directory of Open Access Journals (Sweden)

    Stephen E. Williams

    2011-01-01

    Full Text Available Form and function of mycorrhizas as well as tracing the presence of the mycorrhizal fungi through the geological time scale are herein first addressed. Then mycorrhizas and plant fitness, succession, mycorrhizas and ecosystem function, and mycorrhizal resiliency are introduced. From this, four hypotheses are drawn: (1 mycorrhizal diversity evolved in response to changes in Global Climate Change (GCC environmental drivers, (2 mycorrhizal diversity will be modified by present changes in GCC environmental drivers, (3 mycorrhizal changes in response to ecological drivers of GCC will in turn modify plant, community, and ecosystem responses to the same, and (4 Mycorrhizas will continue to evolve in response to present and future changes in GCC factors. The drivers of climate change examined here are: CO2 enrichment, temperature rise, altered precipitation, increased N-deposition, habitat fragmentation, and biotic invasion increase. These impact the soil-rhizosphere, plant and fungal physiology and/or ecosystem(s directly and indirectly. Direct effects include changes in resource availability and change in distribution of mycorrhizas. Indirect effects include changes in below ground allocation of C to roots and changes in plant species distribution. GCC ecological drivers have been partitioned into four putative time frames: (1 Immediate (1–2 years impacts, associated with ecosystem fragmentation and habitat loss realized through loss of plant-hosts and disturbance of the soil; (2 Short-term (3–10 year impacts, resultant of biotic invasions of exotic mycorrhizal fungi, plants and pests, diseases and other abiotic perturbations; (3 Intermediate-term (11–20 year impacts, of cumulative and additive effects of increased N (and S deposition, soil acidification and other pollutants; and (4 Long-term (21–50+ year impacts, where increased temperatures and CO2 will destabilize global rainfall patterns, soil properties and plant ecosystem resilience. Due

  6. Effect of Arbuscular Mycorrhizal Fungi on Chemical Constituents in Cotton/Alfalfa Mixed Culture

    OpenAIRE

    Ibrahim Mazen

    2017-01-01

    A pot experiment was conducted to study the extent of changes occurring in the nutrients, chlorophyll and protein of plants grown in cotton/alfalfa mixed culture as affected by inoculation with indigenous arbuscular mycorrhizal fungi (AMF). The experiment consisted of mycorrhizal treatments (with and without AMF inoculation) and three planting patterns (cotton monoculture, alfalfa monoculture, cotton/alfalfa mixed culture). Arbuscular mycorrhizal (AM) inoculum previously isolated from a rhizo...

  7. Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula

    Science.gov (United States)

    Konvalinková, Tereza; Püschel, David; Janoušková, Martina; Gryndler, Milan; Jansa, Jan

    2015-01-01

    Plant and fungal partners in arbuscular mycorrhizal symbiosis trade mineral nutrients for carbon, with the outcome of this relationship for plant growth and nutrition being highly context-dependent and changing with the availability of resources as well as with the specific requirements of the different partners. Here we studied how the model legume Medicago truncatula, inoculated or not with a mycorrhizal fungus Rhizophagus irregularis, responded to a gradient of light intensities applied over different periods of time, in terms of growth, phosphorus nutrition and the levels of root colonization by the mycorrhizal fungus. Short-term (6 d) shading, depending on its intensity, resulted in a rapid decline of phosphorus uptake to the shoots of mycorrhizal plants and simultaneous accumulation of phosphorus in the roots (most likely in the fungal tissues), as compared to the non-mycorrhizal controls. There was, however, no significant change in the levels of mycorrhizal colonization of roots due to short-term shading. Long-term (38 d) shading, depending on its intensity, provoked a multitude of plant compensatory mechanisms, which were further boosted by the mycorrhizal symbiosis. Mycorrhizal growth- and phosphorus uptake benefits, however, vanished at 10% of the full light intensity applied over a long-term. Levels of root colonization by the mycorrhizal fungus were significantly reduced by long-term shading. Our results indicate that even short periods of shade could have important consequences for the functioning of mycorrhizal symbiosis in terms of phosphorus transfer between the fungus and the plants, without any apparent changes in root colonization parameters or mycorrhizal growth response, and call for more focused research on temporal dynamics of mycorrhizal functioning under changing environmental conditions. PMID:25763002

  8. Mycorrhizal symbiosis and local adaptation in Aster amellus: a field transplant experiment.

    Science.gov (United States)

    Pánková, Hana; Raabová, Jana; Münzbergová, Zuzana

    2014-01-01

    Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K) and Ceske Stredohori (region S). Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S) in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local adaptation studies

  9. Mycorrhizal symbiosis and local adaptation in Aster amellus: a field transplant experiment.

    Directory of Open Access Journals (Sweden)

    Hana Pánková

    Full Text Available Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K and Ceske Stredohori (region S. Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local

  10. Deep sequencing-based comparative transcriptional profiles of Cymbidium hybridum roots in response to mycorrhizal and non-mycorrhizal beneficial fungi.

    Science.gov (United States)

    Zhao, Xiaolan; Zhang, Jianxia; Chen, Chunli; Yang, Jingze; Zhu, Haiyan; Liu, Min; Lv, Fubing

    2014-08-31

    The Orchidaceae is one of the largest families in the plant kingdom and orchid mycorrhizae (OM) are indispensable in the life cycle of all orchids under natural conditions. In spite of this, little is known concerning the mechanisms underlying orchid- mycorrhizal fungi interactions. Our previous work demonstrated that the non-mycorrhizal fungus Umbelopsis nana ZH3A-3 could improve the symbiotic effects of orchid mycorrhizal fungus Epulorhiza repens ML01 by co-cultivation with Cymbidium hybridum plantlets. Thus, we investigated the C. hybridum transcript profile associated with different beneficial fungi. More than 54,993,972 clean reads were obtained from un-normalized cDNA library prepared from fungal- and mock- treated Cymbidium roots at four time points using RNA-seq technology. These reads were assembled into 16,798 unique transcripts, with a mean length of 1127 bp. A total of 10,971 (65.31%) sequences were annotated based on BLASTX results and over ninety percent of which were assigned to plant origin. The digital gene expression profiles in Cymbidium root at 15 days post inoculation revealed that 1674, 845 and 1743 genes were sigificantly regulated in response to ML01, ZH3A-3 and ML01+ ZH3A-3 treatments, respectively. Twenty-six genes in different regulation patterns were validated using quantitative RT-PCR. Our analysis showed that general defense responses were co- induced by three treatments, including cell wall modification, reactive oxygen species detoxification, secondary biosynthesis and hormone balance. Genes involved in phosphate transport and root morphogenesis were also detected to be up-regulated collectively. Among the OM specifically induced transcripts, genes related to signaling, protein metabolism and processing, defense, transport and auxin response were identifed. Aside from these orchid transcripts, some putative fungal genes were also identified in symbiotic roots related to plant cell wall degradation, remodeling the fungal cell wall and

  11. Cell type-specific protein and transcription profiles implicate periarbuscular membrane synthesis as an important carbon sink in the mycorrhizal symbiosis.

    Science.gov (United States)

    Gaude, Nicole; Schulze, Waltraud X; Franken, Philipp; Krajinski, Franziska

    2012-04-01

    The development of an arbuscular mycorrhizal (AM) symbiosis is a non-synchronous process with typical mycorrhizal root containing different symbiotic stages at one time. Methods providing cell type-specific resolution are therefore required to separate these stages and analyze each particular structure independently from each other. We established an experimental system for analyzing specific proteomic changes in arbuscule-containing cells of Glomus intraradices colonized Medicago truncatula roots. The combination of laser capture microdissection (LCM) and liquid chromatography-tandem mass chromatography (LC-MS/MS) allowed the identification of proteins with specific or increased expression in arbuscule-containing cells. Consistent with previous transcriptome data, the proteome of arbuscule-containing cells showed an increased number of proteins involved in lipid metabolism, most likely related to the synthesis of the periarbuscular membrane. In addition, transcriptome data of non-colonized cells of mycorrhizal roots suggest mobilization of carbon resources and their symplastic transport toward arbuscule-containing cells for the synthesis of periarbuscular membranes. This highlights the periarbuscular membrane as important carbon sink in the mycorrhizal symbiosis.

  12. Detecting nonculturable bacteria in the active mycorrhizal zone of the pine mushroom Tricholoma matsutake.

    Science.gov (United States)

    Kataoka, Ryota; Siddiqui, Zaki Anwar; Kikuchi, Junichi; Ando, Masaki; Sriwati, Rina; Nozaki, Ai; Futai, Kazuyoshi

    2012-04-01

    The fungus Tricholoma matsutake forms an ectomycorrhizal relationship with pine trees. Its sporocarps often develop in a circle, which is commonly known as a fairy ring. The fungus produces a solid, compact, white aggregate of mycelia and mycorrhizae beneath the fairy ring, which in Japanese is called a 'shiro'. In the present study, we used soil dilution plating and molecular techniques to analyze the bacterial communities within, beneath, and outside the T. matsutake fairy ring. Soil dilution plating confirmed previous reports that bacteria and actinomycetes are seldom present in the soil of the active mycorrhizal zone of the T. matsutake shiro. In addition, the results showed that the absence of bacteria was strongly correlated with the presence of T. matsutake mycorrhizae. The results demonstrate that bacteria, especially aerobic and heterotrophic forms, and actinomycetes, are strongly inhibited by T. matsutake. Indeed, neither bacteria nor actinomycetes were detected in 11.3% of 213 soil samples from the entire shiro area by culture-dependent methods. However, molecular techniques demonstrated that some bacteria, such as individual genera of Sphingomonas and Acidobacterium, were present in the active mycorrhizal zone, even though they were not detected in soil assays using the dilution plating technique.

  13. 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.

  14. Growth of a leguminous tree (Centrolobium tomentosum Guill. ex Benth.) inoculated with Rhizobium and mycorrhizal fungi.

    Science.gov (United States)

    Marques, M S; Gonçalves, L M; Lemos-Filho, J P; Rocha, D; Vale, M T; Scotti, M R

    1997-01-01

    Leguminous trees are being suggested for revegetation programs due to their ability to develop associations with rhizobia and mycorrhizal fungi. The growth of a native species of the Tropical Atlantic Forest, Centrolobium tomentosum, was evaluated in a native forest soil and in a Eucalyptus forest soil under different treatments of inoculation. C. tomentosum produced more biomass under nursery conditions after inoculation with Rhizobium BHICB-Ab1 associated with arbuscular mycorrhizal (AM). This treatment improved shoot and root growth and nodule weight under forest soil condition, while in eucalyptus soil only shoot biomass and nodule weight were significantly modified. In another experiment, using forest soil, height and stem diameter were also increased by dual inoculation procedures. The height and diameter growth promoting effect was observed when BHICB-Ab1 was used as inoculant associated with AM, but not with BHICB-Ab1 alone. In contrast, plants inoculated with BHICB-Ab3 alone were similar in height and diameter growth, to those which were inoculated with BHICB-Ab3 associated with AM. These results suggest that benefits of dual inoculation depend on triparty symbiosis and especially on the choice of Rhizobium strain.

  15. Jatropha curcas and assisted phytoremediation of a mine tailing with biochar and a mycorrhizal fungus.

    Science.gov (United States)

    González-Chávez, Ma Del Carmen A; Carrillo-González, Rogelio; Hernández Godínez, María Isabel; Evangelista Lozano, Silvia

    2017-02-01

    Soil pollution is an important ecological problem worldwide. Phytoremediation is an environmental-friendly option for reducing metal pollution. A greenhouse experiment was conducted to determine the growth and physiological response, metal uptake, and the phytostabilization potential of a nontoxic Jatropha curcas L. genotype when grown in multimetal-polluted conditions. Plants were established on a mine residue (MR) amended or not amended with corn biochar (B) and inoculated or not inoculated with the mycorrhizal fungus Acaulospora sp. (arbuscular mycorrhizal fungus, AMF). J. curcas was highly capable of growing in an MR and showed no phytotoxic symptoms. After J. curcas growth (105 days), B produced high desorption of Cd and Pb from the MR; however, no increases in metal shoot concentrations were observed. Therefore, Jatropha may be useful for phytostabilization of metals in mine tailings. The use of B is recommended because improved MR chemical properties conduced to plant growth (cation-exchange capacity, organic matter content, essential nutrients, electrical conductivity, water-holding capacity) and plant growth development (higher biomass, nutritional and physiological performance). Inoculation with an AMF did not improve any plant growth or physiological plant characteristic. Only higher Zn shoot concentration was observed, but it was not phytotoxic. Future studies of B use and its long-term effect on MR remediation should be conducted under field conditions.

  16. Trade-Offs in Arbuscular Mycorrhizal Symbiosis: Disease Resistance, Growth Responses and Perspectives for Crop Breeding

    Directory of Open Access Journals (Sweden)

    Catherine N. Jacott

    2017-11-01

    Full Text Available There is an increasing need to develop high-yielding, disease-resistant crops and reduce fertilizer usage. Combining disease resistance with efficient nutrient assimilation through improved associations with symbiotic microorganisms would help to address this. Arbuscular mycorrhizal fungi (AMF form symbiotic relationships with most terrestrial plants, resulting in nutritional benefits and the enhancement of stress tolerance and disease resistance. Despite these advantages, arbuscular mycorrhizal (AM interactions are not normally directly considered in plant breeding. Much of our understanding of the mechanisms of AM symbiosis comes from model plants, which typically exhibit positive growth responses. However, applying this knowledge to crops has not been straightforward. In many crop plants, phosphate uptake and growth responses in AM-colonized plants are variable, with AM plants exhibiting sometimes zero or negative growth responses and lower levels of phosphate acquisition. Host plants must also balance the ability to host AMF with the ability to resist pathogens. Advances in understanding the plant immune system have revealed similarities between pathogen infection and AM colonization that may lead to trade-offs between symbiosis and disease resistance. This review considers the potential trade-offs between AM colonization, agronomic traits and disease resistance and highlights the need for translational research to apply fundamental knowledge to crop improvement.

  17. Nitrate regulates rhizobial and mycorrhizal symbiosis in common bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Nanjareddy, Kalpana; Blanco, Lourdes; Arthikala, Manoj-Kumar; Affantrange, Xochitl Alvarado; Sánchez, Federico; Lara, Miguel

    2014-03-01

    Nitrogen-limited conditions are considered to be a prerequisite for legume-rhizobial symbiosis, but the effects of nitrate-rich conditions on symbiotic status remain poorly understood. We addressed this issue by examining rhizobial (Rhizobim tropici) and arbusclar mycorrhizal (Glomus intraradices) symbiosis in Phaseolus vulgaris L. cv. Negro Jamapa under nitrate pre-incubation and continuous nitrate conditions. Our results indicate that nitrate pre-incubation, independent of the concentration, did not affect nodule development. However, the continuous supply of nitrate at high concentrations impaired nodule maturation and nodule numbers. Low nitrate conditions, in addition to positively regulating nodule number, biomass, and nitrogenase activity, also extended the span of nitrogen-fixing activity. By contrast, for arbuscular mycorrhizae, continuous 10 and 50 mmol/L nitrate increased the percent root length colonization, concomitantly reduced arbuscule size, and enhanced ammonia transport without affecting phosphate transport. Therefore, in this manuscript, we have proposed the importance of nitrate as a positive regulator in promoting both rhizobial and mycorrhizal symbiosis in the common bean. © 2014 Institute of Botany, Chinese Academy of Sciences.

  18. Mycorrhizal Fungal Diversity and Community Composition in Two Closely Related Platanthera (Orchidaceae) Species.

    Science.gov (United States)

    Esposito, Fabiana; Jacquemyn, Hans; Waud, Michael; Tyteca, Daniel

    2016-01-01

    While it is generally acknowledged that orchid species rely on mycorrhizal fungi for completion of their life cycle, little is yet known about how mycorrhizal fungal diversity and community composition vary within and between closely related orchid taxa. In this study, we used 454 amplicon pyrosequencing to investigate variation in mycorrhizal communities between pure (allopatric) and mixed (sympatric) populations of two closely related Platanthera species (Platanthera bifolia and P. chlorantha) and putative hybrids. Consistent with previous research, the two species primarily associated primarily with members of the Ceratobasidiaceae and, to a lesser extent, with members of the Sebacinales and Tulasnellaceae. In addition, a large number of ectomycorrhizal fungi belonging to various families were observed. Although a considerable number of mycorrhizal fungi were common to both species, the fungal communities were significantly different between the two species. Individuals with intermediate morphology showed communities similar to P. bifolia, confirming previous results based on the genetic architecture and fragrance composition that putative hybrids essentially belonged to one of the parental species (P. bifolia). Differences in mycorrhizal communities between species were smaller in mixed populations than between pure populations, suggesting that variation in mycorrhizal communities was largely controlled by local environmental conditions. The small differences in mycorrhizal communities in mixed populations suggests that mycorrhizal fungi are most likely not directly involved in maintaining species boundaries between the two Platanthera species. However, seed germination experiments are needed to unambiguously assess the contribution of mycorrhizal divergence to reproductive isolation.

  19. On the perils of mycorrhizal status lists: the case of Buddleja davidii.

    Science.gov (United States)

    Dickie, I A; Thomas, M M; Bellingham, P J

    2007-11-01

    One observation in a mycorrhizal check-list that Buddleja davidii is nonmycorrhizal has been perpetuated in subsequent citations and used in a number of analyses of mycorrhizal ecology and evolution. Direct observation of B. davidii from New Zealand and the UK shows extensive arbuscular mycorrhizal fungal structures inside B. davidii roots. The suggestion that B. davidii is nonmycorrhizal is therefore not supported. The use of mycorrhizal checklists for analysis of plant traits and evolution needs to be undertaken with care to ensure the validity of underlying data.

  20. RESPONSE OF TWO SUNFLOWER (HELIANTHUS ANNUUS L. GENOTYPES TO VA-MYCORRHIZAL INOCULATION AND PHOSPHORUS LEVELS

    Directory of Open Access Journals (Sweden)

    C.P. CHANDRASHEKARA, V.C. PATIL

    1995-01-01

    Full Text Available The performance of two sunflower genotypes (Morden and MSFH-8 with and without VA-mycorrhizal fungi at three P levels (38, 56 and 75 kg P2O5 ha-1 in vertisol of Dharwad was studied to determine the effect of mycorrhizal inoculation on plant growth, yield and P uptake. The results showed that the VAM inoculation increased sunflower yield (14%, total biomass (16%, oil content (3.1% and P uptake (30.5% over uninoculated control. The percent root colonization and chlamydo-spore count decreased with increasing P levels. The total biomass production, seed yield and P uptake of mycorrhizal plants at 38 kg P2O5 ha-1 more than the non-mycorrhizal plants at 75 kg P2O5 ha-1. The biomass and seed yield of mycorrhizal plants at same P level were more than the non-mycorrhizal plants. Mycorrhizal plants of Morden at 38 kg P2O5 ha-1 and MSFH-8 at 56 kg P2O5 ha-1 produced higher seed yield, oil content and total biomass than non-mycorrhizal plants supplied with 75 kg P2O5 ha-1. The results indicated that, VA-mycorrhizal inoculation helps in saving 25 and 50 percent of recommended dose of phosphatic fertilizer (75 kg P2O5 ha-1 in MSFH-8 (single cross hybrid and Morden (open pollinated variety, respectively.

  1. Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System

    Science.gov (United States)

    Garcés-Ruiz, Mónica; Calonne-Salmon, Maryline; Plouznikoff, Katia; Misson, Coralie; Navarrete-Mier, Micaela; Cranenbrouck, Sylvie; Declerck, Stéphane

    2017-01-01

    A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi) uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h) from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h) as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements. PMID:28890723

  2. Role of VAM on growth and phosphorus nutrition of maize with low soluble phosphate fertilization

    OpenAIRE

    Amitava Rakshit; Pratapbhanu S Bhadoria

    2010-01-01

    The effect of vesicular arbuscular mycorrhizal (VAM) infection on growth and P nutrition in Maize (Zea mays, cv.DDH hybrid) were assessed in Oxisol pot experiment. Maize was grown inoculated with spores of VAM fungi Glomus mosseae or non-inoculated. Low soluble ferrous phosphate (FePO4.4H2O) was added to the mycorrhized and non-micrrohized maized. The dry weight of mycorrhized plants with added phosphate (P) were higher than in mycorrhized plants without added P or non-mycorrhized plants with...

  3. Underground resource allocation between individual networks of mycorrhizal fungi

    DEFF Research Database (Denmark)

    Mikkelsen, Bolette Lind; Rosendahl, Søren; Jakobsen, Iver

    2008-01-01

    * Fusions between individual mycelia of arbuscular mycorrhizal (AM) fungi have been observed in two-dimensional systems but never in soil systems. Here, phosphorus ((32)P) labelling was used to demonstrate nutrient transfer between individual mycelia and to investigate the possible role of anasto......* Fusions between individual mycelia of arbuscular mycorrhizal (AM) fungi have been observed in two-dimensional systems but never in soil systems. Here, phosphorus ((32)P) labelling was used to demonstrate nutrient transfer between individual mycelia and to investigate the possible role...... of G. mosseae overlapped. The transfer probably occurred via anastomoses between the mycelia as no transfer of (32)P was detected between the mycelia of different fungi at the second harvest. * The indicated ability of AM fungal mycelia to anastomose in soil has implications for the formation of large...

  4. [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.

  5. Effects of organic farming on communities of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Lee, Si-Woo; Lee, Eun-Hwa; Eom, Ahn-Heum

    2008-03-01

    Red pepper (Capsicum annum L.) roots and soils representing different agricultural management practices such as conventional (CON), no-chemical (NOC), and organic farming systems (ORG) were collected from 32 farm field sites in Kyunggi, Korea to investigate the effects of these agricultural practices on arbuscular mycorrhizal (AM) symbiosis. ORG inoculum significantly increased plant growth compared to inoculum from CON and NOC. A community analysis of AM fungi (AMF) using morphological features of spores revealed that AMF spore abundance and species diversity were significantly higher in ORG than in CON. Additionally, a community analysis of AMF colonizing roots using a molecular technique revealed higher AMF diversity in ORG than in CON. These results suggest that agricultural practices significantly influence AM fungal community structure and mycorrhizal inoculum potential.

  6. Leaf elemental analysis in mycorrhizal post oak seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Boling, B.C. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Naab, F.U. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)]. E-mail: fun001@unt.edu; Smith, D. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Duggan, J.L. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); McDaniel, F.D. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)

    2006-09-15

    Growth and element assimilation was investigated in the leaves of post oak seedlings exposed to four different treatment combinations of fertilization and ectomycorrhizal inoculation. Element concentration was analyzed via particle-induced X-ray emission spectrometry (PIXE). PIXE detected 10 of the 13 essential macro and micronutrients: P, S, Mg, Ca, K, Cu, Zn, Mn, Fe and Cl. Mean growth and dry weight was significantly different across the treatment groups as well as the mean concentration of Mg, Al, S, K, Ca, Fe, Cu and Zn. The data suggest that fertilization rather than mycorrhizal inoculation had a stronger influence on nutrient uptake. This study is the first to analyze element concentration in post oak and to investigate the potential benefits of mycorrhizal symbiosis in post oak seedlings in terms of nutrient uptake.

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

    OpenAIRE

    Benjamin A. Sikes

    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...

  8. Edible mycorrhizal mushrooms as sources of bioactive phenolic compounds.

    OpenAIRE

    João C. M. Barreira; Barros, Lillian; Martins, Anabela; Isabel C. F. R. Ferreira

    2011-01-01

    Mushrooms are emerging as one of the most appreciated foods on a global basis. Besides their nutritional properties and unique organoleptic characteristics, mushrooms might act as functional foods in view of the medicinal properties of their bioactive compounds [1,2]. Those medicinal properties are often due the antioxidant activity of specific molecules such as phenolic compounds [3]. In the present work, five edible mycorrhizal mushoom species (Amanita caesarea, Cortinarius anomalus, Co...

  9. The role of mycorrhizal associations in plant potassium nutrition

    OpenAIRE

    Garcia, Kevin; Zimmermann, Sabine D.

    2014-01-01

    Potassium (K+) is one of the most abundant elements of soil composition but it's very low availability limits plant growth and productivity of ecosystems. Because this cation participates in many biological processes, its constitutive uptake from soil solution is crucial for the plant cell machinery. Thus, the understanding of strategies responsible of K+ nutrition is a major issue in plant science. Mycorrhizal associations occurring between roots and hyphae of underground fungi improve hydro...

  10. Regulation of Plant Growth, Photosynthesis, Antioxidation and Osmosis by an Arbuscular Mycorrhizal Fungus in Watermelon Seedlings under Well-Watered and Drought Conditions.

    Science.gov (United States)

    Mo, Yanling; Wang, Yongqi; Yang, Ruiping; Zheng, Junxian; Liu, Changming; Li, Hao; Ma, Jianxiang; Zhang, Yong; Wei, Chunhua; Zhang, Xian

    2016-01-01

    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 (WUE) 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 superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and [Formula: see text] 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

  11. 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.

  12. Relationship between soil nutrients and mycorrhizal associations of two Bipinnula species (Orchidaceae) from central Chile.

    Science.gov (United States)

    Mujica, María Isabel; Saez, Nicolás; Cisternas, Mauricio; Manzano, Marlene; Armesto, Juan J; Pérez, Fernanda

    2016-07-01

    Mycorrhizal associations are influenced by abiotic and biotic factors, including climate, soil conditions and the identity of host plants. However, the effect of environmental conditions on orchid mycorrhizal associations remains poorly understood. The present study examined how differences in soil nutrient availability are related to the diversity and composition of mycorrhizal fungi associated with two terrestrial orchid species from central Chile. For 12 populations of Bipinnula fimbriata and B. plumosa, OTU (operational taxonomic unit) richness, phylogenetic diversity and community composition of mycorrhizal fungi in root samples were estimated using internal transcribed spacer (ITS) sequences. Then, these mycorrhizal diversity variables were related to soil nutrients and host species using generalized linear models and non-metric multidimensional scaling. Variation in OTU composition of mycorrhizal fungi among sites was explained mainly by orchid host species. Fungi in Tulasnellaceae and Ceratobasidiaceae were isolated from both orchid species, but the former were more frequent in B. fimbriata and the latter in B. plumosa. Soil nutrients and orchid host species had significant effects on OTU richness and phylogenetic diversity. Mycorrhizal diversity decreased in habitats with higher N in both species and increased with P availability only in B. fimbriata The results suggest that soil nutrient availability modulates orchid mycorrhizal associations and provide support for the hypothesis that specialization is favoured by higher soil nutrient availability. Inter-specific differences in mycorrhizal composition can arise due to a geographical pattern of distribution of orchid mycorrhizal fungi, host preferences for fungal partners or differential performance of mycorrhizal fungi under different nutrient availabilities. Further experiments are needed to evaluate these hypotheses. © The Author 2016. Published by Oxford University Press on behalf of the Annals of

  13. Interplant Communication of Tomato Plants through Underground Common Mycorrhizal Networks

    Science.gov (United States)

    Song, Yuan Yuan; Zeng, Ren Sen; Xu, Jian Feng; Li, Jun; Shen, Xiang; Yihdego, Woldemariam Gebrehiwot

    2010-01-01

    Plants can defend themselves to pathogen and herbivore attack by responding to chemical signals that are emitted by attacked plants. It is well established that such signals can be transferred through the air. In theory, plants can also communicate with each other through underground common mycorrhizal networks (CMNs) that interconnect roots of multiple plants. However, until now research focused on plant-to-plant carbon nutrient movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal networks. Here, we show that CMNs mediate plant-plant communication between healthy plants and pathogen-infected tomato plants (Lycopersicon esculentum Mill.). After establishment of CMNs with the arbuscular mycorrhizal fungus Glomus mosseae between tomato plants, inoculation of ‘donor’ plants with the pathogen Alternaria solani led to increases in disease resistance and activities of the putative defensive enzymes, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and lipoxygenase in healthy neighbouring ‘receiver’ plants. The uninfected ‘receiver’ plants also activated six defence-related genes when CMNs connected ‘donor’ plants challenged with A. solani. This finding indicates that CMNs may function as a plant-plant underground communication conduit whereby disease resistance and induced defence signals can be transferred between the healthy and pathogen-infected neighbouring plants, suggesting that plants can ‘eavesdrop’ on defence signals from the pathogen-challenged neighbours through CMNs to activate defences before being attacked themselves. PMID:20967206

  14. The role of mycorrhizal associations in plant potassium nutrition

    Directory of Open Access Journals (Sweden)

    Kevin eGarcia

    2014-07-01

    Full Text Available Potassium (K+ is one of the most abundant elements of soil composition but its very low availability limits plant growth and productivity of ecosystems. Because this cation participates in many biological processes, its constitutive uptake from soil solution is crucial for the plant cell machinery. Thus, the understanding of strategies responsible of K+ nutrition is a major issue in plant science. Mycorrhizal associations occurring between roots and hyphae of underground fungi improve hydro-mineral nutrition of the majority of terrestrial plants. The contribution of this mutualistic symbiosis to the enhancement of plant K+ nutrition is not well understood and poorly studied so far. This mini-review examines the current knowledge about the impact of both arbuscular mycorrhizal and ectomycorrhizal symbioses on the transfer of K+ from the soil to the plants. A model summarizing plant and fungal transport systems identified and hypothetically involved in K+ transport is proposed. In addition, some data related to benefits for plants provided by the improvement of K+ nutrition thanks to mycorrhizal symbioses are presented.

  15. The role of mycorrhizal associations in plant potassium nutrition

    Science.gov (United States)

    Garcia, Kevin; Zimmermann, Sabine D.

    2014-01-01

    Potassium (K+) is one of the most abundant elements of soil composition but it's very low availability limits plant growth and productivity of ecosystems. Because this cation participates in many biological processes, its constitutive uptake from soil solution is crucial for the plant cell machinery. Thus, the understanding of strategies responsible of K+ nutrition is a major issue in plant science. Mycorrhizal associations occurring between roots and hyphae of underground fungi improve hydro-mineral nutrition of the majority of terrestrial plants. The contribution of this mutualistic symbiosis to the enhancement of plant K+ nutrition is not well understood and poorly studied so far. This mini-review examines the current knowledge about the impact of both arbuscular mycorrhizal and ectomycorrhizal symbioses on the transfer of K+ from the soil to the plants. A model summarizing plant and fungal transport systems identified and hypothetically involved in K+ transport is proposed. In addition, some data related to benefits for plants provided by the improvement of K+ nutrition thanks to mycorrhizal symbioses are presented. PMID:25101097

  16. Growth response of Pterocarpus soyauxii and Lophira alata seedlings to host soil mycorrhizal inocula in relation to land use types.

    NARCIS (Netherlands)

    Onguene, N.A.; Ngonkeu, L.E.M.; Kuyper, T.W.

    2011-01-01

    Deficiency in mycorrhizal inoculum in soils due to land use types (LUT) can be alleviated by quantity and quality inoculum addition. A bioassay was carried out to determine how host soil mycorrhizal inoculum influenced mycorrhizal colonization, carbon allocation and partitioning of seedlings of two

  17. Microscopic characterization of orchid mycorrhizal fungi: Scleroderma as a putative novel orchid mycorrhizal fungus of Vanilla in different crop systems.

    Science.gov (United States)

    González-Chávez, Ma Del Carmen A; Torres-Cruz, Terry J; Sánchez, Samantha Albarrán; Carrillo-González, Rogelio; Carrillo-López, Luis Manuel; Porras-Alfaro, Andrea

    2018-02-01

    Vanilla is an orchid of economic importance widely cultivated in tropical regions and native to Mexico. We sampled three species of Vanilla (V. planifolia, V. pompona, and V. insignis) in different crop systems. We studied the effect of crop system on the abundance, type of fungi, and quality of pelotons found in the roots using light and electron microscopy and direct sequencing of mycorrhizal structures. Fungi were identified directly from pelotons obtained from terrestrial roots of vanilla plants in the flowering stage. Root samples were collected from plants in crop systems located in the Totonacapan area in Mexico (states of Puebla and Veracruz). DNA was extracted directly from 40 pelotons and amplified using ITS rRNA sequencing. Peloton-like structures were observed, presenting a combination of active pelotons characterized by abundant hyphal coils and pelotons in various stages of degradation. The most active pelotons were observed in crop systems throughout living tutors (host tree) in comparison with roots collected from dead or artificial tutors. Fungi identified directly from pelotons included Scleroderma areolatum, a common ectomycorrhizal fungus that has not been reported as a mycorrhizal symbiont in orchids. Direct amplification of pelotons also yielded common plant pathogens, including Fusarium and Pyrenophora seminiperda, especially in those sites with low colonization rates, and where large numbers of degraded pelotons were observed. This research reports for the first time the potential colonization of Vanilla by Scleroderma, as a putative orchid mycorrhizal symbiont in four sites in Mexico and the influence of crop system on mycorrhizal colonization on this orchid.

  18. Mycorrhizal Productivity Following Woody Plant Invasion of Grassland

    Science.gov (United States)

    Boutton, T. W.; Rowe, H. I.; Ariza, M. C.; Miller, R. M.; Filley, T. R.

    2008-12-01

    Mycorrhizal fungi play an important role in soil carbon storage and dynamics through the production of recalcitrant organic compounds (e.g., glomalin and chitin), and through the production of hyphae which entangle and enmesh soil particles to form aggregates which physically protect organic matter from decomposer organisms. Despite these important functions, little is known regarding rates of mycorrhizal productivity and how these rates might be influenced by changes in plant community composition. We quantified mycorrhizal production in a subtropical savanna parkland in southern Texas where woody plants have invaded areas that were once open grassland. Mycorrhizal ingrowth bags (3 x 10 cm) were made from 50 μm nylon mesh, filled with sterile sand (200-600 μm particle size), and deployed in the field in triplicate in remnant grasslands (n=15), and in woody plant stands (n=13) ranging in age from 15 to 86 yrs. Ingrowth bags were installed in May and harvested in Oct 2007 after 156 days. Hyphae were isolated by flotation/filtration, cleaned thoroughly to remove sand, freeze-dried, and weighed. Microscopic examination indicated that nearly all hyphae recovered from ingrowth bags were from arbuscular mycorrhizal fungi. During the ingrowth period, nearly 4X more hyphal biomass accumulated in wooded areas (9.00 ± 3.84 g m- 2) compared to remnant grasslands (2.35 ± 0.56 g m-2). Hyphal productivity rates increased linearly with woody plant stand age (r = 0.89) from 15 ± 4 mg m-2 day-1 in grasslands (time 0) up to 58-98 mg m-2 day-1 in wooded areas >65 yrs old. When these productivity rates are annualized, we find that hyphal productivity represents approximately 4% of aboveground net primary productivity (ANPP) in wooded areas, and 2% of ANPP in remnant grasslands. These observations are consistent with concurrent studies showing that glomalin concentrations and chitinase enzyme activity both increase in soils with time following woody encroachment into grassland

  19. Towards the antioxidant and chemical characterization of mycorrhizal mushrooms from Northeast Portugal

    OpenAIRE

    Filipa S. Reis; Sandrina A. Heleno; Barros, Lillian; Sousa, Maria João; Martins, Anabela; Santos-Buelga, Celestino; Isabel C. F. R. Ferreira

    2011-01-01

    Mushrooms are widely appreciated all over the world for their nutritional properties and pharmacological value as sources of important bioactive compounds. Mycorrhizal macrofungi associate with plant roots constituting a symbiotic relationship. This symbiosis could influence the production of secondary metabolites, including bioactive compounds. We focused on the evaluation of antioxidant potential and chemical composition of mycorrhizal mushrooms species from Northeast Portugal: Amanita cae...

  20. 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

  1. Role of mycorrhizal fungi and salicylic acid in salinity tolerance of ...

    African Journals Online (AJOL)

    Salinity is one of the common agricultural and biological problems. Most researchers showed that inoculation of plants with mycorrhizal fungi and using salicylic acid increase tolerance of plants due to salinity. In this study, the effect of mycorrhizal fungi, including Glomus mosseae, Glomus intraradices, and salicylic acid (0.2 ...

  2. Phosphate uptake from phytate due to hyphae-mediated phytase activity by arbuscular mycorrhizal maize

    NARCIS (Netherlands)

    Wang, Xinxin; Hoffland, Ellis; Feng, Gu; Kuijper, Thomas

    2017-01-01

    Phytate is the most abundant form of soil organic phosphorus (P). Increased P nutrition of arbuscular mycorrhizal plants derived from phytate has been repeatedly reported. Earlier studies assessed acid phosphatase rather than phytase as an indication of mycorrhizal fungi-mediated phytate use. We

  3. Symbiont identity matters: carbon and phosphorus fluxes between Medicago truncatula and different arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Lendenmann, Mark; Thonar, Cécile; Barnard, Romain L; Salmon, Yann; Werner, Roland A; Frossard, Emmanuel; Jansa, Jan

    2011-11-01

    Many studies have scrutinized the nutritional benefits of arbuscular mycorrhizal associations to their host plants, while the carbon (C) balance of the symbiosis has often been neglected. Here, we present quantification of both the C costs and the phosphorus (P) uptake benefits of mycorrhizal association between barrel medic (Medicago truncatula) and three arbuscular mycorrhizal fungal species, namely Glomus intraradices, Glomus claroideum, and Gigaspora margarita. Plant growth, P uptake and C allocation were assessed 7 weeks after sowing by comparing inoculated plants with their non-mycorrhizal counterparts, supplemented with different amounts of P. Isotope tracing ³³P and ¹³C) was used to quantify both the mycorrhizal benefits and the costs, respectively. G. intraradices supported greatest plant P acquisition and incurred high C costs, which lead to similar plant growth benefits as inoculation with G. claroideum, which was less efficient in supporting plant P acquisition, but also required less C. G. margarita imposed large C requirement on the host plant and provided negligible P uptake benefits. However, it did not significantly reduce plant growth due to sink strength stimulation of plant photosynthesis. A simple experimental system such as the one established here should allow quantification of mycorrhizal costs and benefits routinely on a large number of experimental units. This is necessary for rapid progress in assessment of C fluxes between the plants and different mycorrhizal fungi or fungal communities, and for understanding the dynamics between mutualism and parasitism in mycorrhizal symbioses.

  4. Resilience of arctic mycorrhizal fungal communities after wildfire facilitated by resprouting shrubs

    Science.gov (United States)

    Rebecca E. Hewitt; Elizabeth Bent; Teresa N. Hollingsworth; F. Stuart Chapin; D. Lee. Taylor

    2013-01-01

    Climate-induced changes in the tundra fire regime are expected to alter shrub abundance and distribution across the Arctic. However, little is known about how fire may indirectly impact shrub performance by altering mycorrhizal symbionts. We used molecular tools, including ARISA and ITS sequencing, to characterize the mycorrhizal communities on resprouting ...

  5. Arbuscular mycorrhizal fungi status of some crops in the cross river ...

    African Journals Online (AJOL)

    The incidence of arbuscular mycorrhizal fungi (AMF) colonization and rhizospheric spore prevalence of ten crops was studied in relation to their foliar concentration of nitrogen, phosphorus and potassium in the Calabar area of the Cross River Basin of Nigeria in order to determine their mycorrhizal status. All crops studied ...

  6. Decline of carpophores of mycorrhizal fungi in stands of Pinus sylvestris

    NARCIS (Netherlands)

    Termorshuizen, A.J.

    1990-01-01

    The carpophores of mycorrhizal fungi have declined drastically during this century in the Netherlands and in other European countries. In contrast, saprophytic and pathogenic fungi did not show a significant change. In this thesis, the possible causes of the decline of mycorrhizal mycoflora

  7. Determinants of arbuscular mycorrhizal communities - soil properties or land use?

    Science.gov (United States)

    Jansa, J.; Erb, A.; Oberholzer, H.-R.; Šmilauer, P.; Egli, S.

    2012-04-01

    Arbuscular mycorrhizal (AM) fungi accompanied terrestrial plants since some 500 million years of their evolution and are now widespread in all continents and virtually all soils of the world. They establish symbiotic interactions with a majority of extant higher plant species including most economically important plants. They are heavily implicated in plant nutrition, plant-soil carbon cycling, and tolerance to environmental stresses. Under field conditions, AM fungi usually form multispecies communities both in the soils and in plant roots, and it is becoming well established that various human interventions like cropping, crop rotation, tillage, and fertilization may all drive changes in the community composition of these fungi and, consequently, in the symbiotic benefits to the plants. Most of current evidence is stemming from individual short and long-term field trials, and the different studies usually employed diverse approaches, limiting the comparability of results across sites. Large scale sampling designs using unified research methods across different soil types and land use systems have hardly been employed so far. However, this would be imperative to allow direct comparisons of the effects of various environmental conditions (soil type, climate) and human land use practices on the indigenous soil-borne symbiotic microbes in general and the AM fungi in particular. To contribute to filling this gap, we conducted molecular profiling of AM communities in more than 150 Swiss agricultural soils, developed on a range of parent materials, covering a wide range of soil properties such as pH value, texture, carbon content and altitude, and including highly productive fields through alpine pastures. This study indicated strong correlations between AM fungal community patterns and features like soil pH and texture, as well as some consistent shifts in fungal communities due to specific aspects of land use like tillage or fertilization. These results thus appear to

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

    Directory of Open Access Journals (Sweden)

    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

  9. Transcriptomes of Arbuscular Mycorrhizal Fungi and Litchi Host Interaction after Tree Girdling.

    Science.gov (United States)

    Shu, Bo; Li, Weicai; Liu, Liqin; Wei, Yongzan; Shi, Shengyou

    2016-01-01

    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 chinensis 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 ligase complex

  10. Responses of mycorrhizal fungi and other rootassociated fungi to climate change

    DEFF Research Database (Denmark)

    Merrild, Marie Porret

    Climate change is expected to affect many terrestrial ecosystem processes. Mycorrhizal fungi are important to soil carbon (C) and nutrient cycling thus changes in abundance of mycorrhizal fungi could alter ecosystem functioning. The aim of the present thesis was therefore to investigate responses...... of mycorrhizal fungi to climate change in a seasonal and long-term perspective. Effects of elevated CO2 (510 ppm), night-time warming and extended summer drought were investigated in the long-term field experiment CLIMAITE located in a Danish semi-natural heathland. Mycorrhizal colonization was investigated...... levels. Colonization by arbuscular mycorrhizal (AM) fungi increased under elevated CO2 and warming in spring while ericoid mycorrhiza (ErM) colonisation decreased in response to drought and warming. Increased AM colonization correlated with higher phosphorus and nitrogen root pools. Dark septate...

  11. Effects of arbuscular mycorrhizal fungi on nutrient uptake of maize in reclaimed soil

    Energy Technology Data Exchange (ETDEWEB)

    Bi, Y.; Hu, Z.; Si, J.; Quan, W. [China University of Mining and Technology (CUMT), Beijing (China). Dept. of Resources Exploitation Engineering

    2002-05-01

    An experiment was carried out on the effects of arbuscular mycorrhizal (AM) fungi, glomus mosseae, on the growth and nutrient uptaking of maize in reclaimed soil with coal fly ash layers at different depths. The research shows that plant yields increase with soil depth. Mycorrhizal plants can absorb more nutrients than non-mycorrhizal ones, and transport less Na to shoot, protecting plants from the excessive accumulation of Na. Plant biomass and nutrient content for mycorrhizal plants in reclaimed soil with a small soil thickness of 5 cm and a great fly ash thickness of 10 cm are higher than those for non-mycorrhizal plants in reclaimed soil with a great soil thickness of 10 cm and a small fly ash thickness of 5 cm. Arbuscular mycorrhizae have a potential to counteract the effect induced by a small thickness of covered soil, and so can reduce reclamation fee. 20 refs., 6 tabs.

  12. Mycorrhizal fungal diversity and community composition in a lithophytic and epiphytic orchid.

    Science.gov (United States)

    Xing, Xiaoke; Gai, Xuege; Liu, Qiang; Hart, Miranda M; Guo, Shunxing

    2015-05-01

    Some orchid species are present as epiphytes and lithophytes in the same habitat, but little is known about the differences of their mycorrhizal fungal communities. We used Coelogyne viscosa, which occurs both as an epiphyte and a lithophyte, as a study system to investigate orchid mycorrhizal fungal communities in lithophytes and epiphytes in Xishuangbanna National Nature Reserve (Yunnan Province, China). Twenty-three fungal operational taxonomic units (OTUs) from 18 sampling sites were identified. Results indicated that mycorrhizal fungal community composition was different between epi- and lithophytes. When we analyzed the Tulasnellaceae and Sebacinales communities separately, we found that the Sebacinales fungal communities were significantly different in the two growth habitats, but the Tulasnellaceae fungal communities were not. Our results provide evidence for distinct orchid mycorrhiza fungal communities depending on the growth habitat of the orchid. Consistent with some recent investigations of mycorrhizal fungus community composition, this study suggests that for one orchid, growth habitat affects mycorrhizal symbioses.

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

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2011-01-01

    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.

  14. Comparison of green and albino individuals of the partially mycoheterotrophic orchid Epipactis helleborine on molecular identities of mycorrhizal fungi, nutritional modes and gene expression in mycorrhizal roots.

    Science.gov (United States)

    Suetsugu, Kenji; Yamato, Masahide; Miura, Chihiro; Yamaguchi, Katsushi; Takahashi, Kazuya; Ida, Yoshiko; Shigenobu, Shuji; Kaminaka, Hironori

    2017-03-01

    Some green orchids obtain carbon from their mycorrhizal fungi, as well as from photosynthesis. These partially mycoheterotrophic orchids sometimes produce fully achlorophyllous, leaf-bearing (albino) variants. Comparing green and albino individuals of these orchids will help to uncover the molecular mechanisms associated with mycoheterotrophy. We compared green and albino Epipactis helleborine by molecular barcoding of mycorrhizal fungi, nutrient sources based on 15 N and 13 C abundances and gene expression in their mycorrhizae by RNA-seq and cDNA de novo assembly. Molecular identification of mycorrhizal fungi showed that green and albino E. helleborine harboured similar mycobionts, mainly Wilcoxina. Stable isotope analyses indicated that albino E. helleborine plants were fully mycoheterotrophic, whereas green individuals were partially mycoheterotrophic. Gene expression analyses showed that genes involved in antioxidant metabolism were upregulated in the albino variants, which indicates that these plants experience greater oxidative stress than the green variants, possibly due to a more frequent lysis of intracellular pelotons. It was also found that some genes involved in the transport of some metabolites, including carbon sources from plant to fungus, are higher in albino than in green variants. This result may indicate a bidirectional carbon flow even in the mycoheterotrophic symbiosis. The genes related to mycorrhizal symbiosis in autotrophic orchids and arbuscular mycorrhizal plants were also upregulated in the albino variants, indicating the existence of common molecular mechanisms among the different mycorrhizal types. © 2017 John Wiley & Sons Ltd.

  15. 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. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. Mycorrhizal fungi show regular community compositions in natural ecosystems.

    Science.gov (United States)

    Verbruggen, Erik; Sheldrake, Merlin; Bainard, Luke D; Chen, Baodong; Ceulemans, Tobias; De Gruyter, Johan; Van Geel, Maarten

    2017-10-06

    Dissimilarity overlap curve analysis has shown that 'universality' is a common feature in many complex microbial communities, suggesting that the same taxa interact in a similar manner when shared between communities. We present evidence that arbuscular mycorrhizal fungi, common plant root symbionts, show universal community compositions in natural ecosystems and that this pattern is conserved even at larger spatial scales. However, universality was not detected in agricultural ecosystems potentially implying that agricultural symbiont communities are formed in a different manner.The ISME Journal advance online publication, 6 October 2017; doi:10.1038/ismej.2017.169.

  17. [Effects of arbuscular mycorrhizal fungi on terpenoids in Isodon adenantha].

    Science.gov (United States)

    Han, Bing-Yang; Wang, Ke-Dong; Zhou, Nong; Jiang, Bei

    2013-02-01

    To observe the effects of Arbuscular Mycorrhizal (AM) fungi on terpenoids in Isodon adenantha. Three different treated plant groups were divided as followings: indoor inoculation with AM fungi, non-inoculation with AM fungi, and outdoor natural growth, the effects of AM fungi on the major terpenoids in Isodon adenantha were evaluated. AM fungi had little influence on the content of terpenoids in underground part of Isodon adenantha, but they showed great impact on the content of terpenoids in the aerial part of the plant. The content of terpenoids in the aerial part of Isodon adenantha is positively correlated with AM fungi.

  18. Using in situ seed baiting technique to isolate and identify endophytic and mycorrhizal fungi from seeds of a threatened epiphytic orchid, Dendrobium friedericksianum Rchb.f. (Orchidaceae)

    OpenAIRE

    Khamchatra, Na-monrug; Dixon, Kingsley; Chayamarit, Kongkanda; Apisitwanich, Somsak; Tantiwiwat, Sureeya

    2016-01-01

    All orchids require association with mycorrhizal fungi for seed germination and development under natural conditions but their identification and feasibility are not known. The in situ seed baiting germination was examined of Dendrobium friedericksianum Rchb.f., a native threatened epiphytic orchid species, to detect fungi that promote germination. It was found that seed germination percentages were lowered by 0.1%, with a total of seven protocorms formed. Six endophytic fungi were isolated f...

  19. Nitrogen isotope fractionation during N uptake via arbuscular mycorrhizal and ectomycorrhizal fungi into grey alder.

    Science.gov (United States)

    Schweiger, Peter F

    2016-10-20

    Arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi affect plant nitrogen (N) dynamics. Plant N isotope patterns have been used to characterise the contribution of ECM fungi to plant N uptake. By quantifying and comparing the effects of an AM and an ECM fungus on growth, N uptake and isotopic composition of one host plant grown at different relative N supply levels, the aim of this study was to improve the mechanistic understanding of natural 15N abundance patterns in mycorrhizal plants and their underlying causes. Grey alders were inoculated with one ECM fungus or one AM fungus or left non-mycorrhizal. Plants were grown under semi-hydroponic conditions and were supplied with three rates of relative N supply ranging from deficient to luxurious. Neither mycorrhizal fungus increased plant growth or N uptake. AM root colonisation had no effect on whole plant δ15N and decreased foliar δ 15N only under N deficiency. The roots of these plants were 15N-enriched. ECM root colonisation consistently decreased foliar and whole plant δ15N. It is concluded, that both mycorrhizal fungi contributed to plant N uptake into the shoot. Nitrogen isotope fractionation during N assimilation and transformations in fungal mycelia is suggested to have resulted in plants receiving 15N-depleted N via the mycorrhizal uptake pathways. Negative mycorrhizal growth effects are explained by symbiotic resource trade on carbon and N and decreased direct plant N uptake. Copyright © 2016 Elsevier GmbH. All rights reserved.

  20. Resource allocation in an annual herb: Effects of light, mycorrhizal fungi, and defoliation

    Science.gov (United States)

    Aguilar-Chama, Ana; Guevara, Roger

    2016-02-01

    Concurrent interactions and the availability of resources (e.g., light) affect the cost/benefit balance during mutualistic and antagonistic interactions, as well as plant resource allocation patterns. Mycorrhizal interactions and herbivory concur in most plants, where mycorrhizae can enhance the uptake of soil nutrients by plants as well as consuming a large fraction of the plant's carbon, and defoliation usually reduces light interception and photosynthesis, thereby causing direct losses to the hosts of mycorrhizal fungi. Both types of interactions affect the carbon budget of their host plants and thus we predict that the relative costs of herbivory and mycorrhizal colonization will increase when photosynthesis is reduced, for instance in light limited environments. We conducted a greenhouse experiment using Datura stramonium to investigate the effects of defoliation and mycorrhizal inoculation on the resource allocation patterns in two different light environments. Defoliated plants overcompensated in terms of leaf mass in both light environments, but total seed mass per fruit was negatively affected by defoliation in both light environments. Mycorrhizal inoculation had a positive effect on vegetative growth and the leaf nitrogen content, but defoliation negates the benefit of mycorrhizal interactions in terms of the leaf nitrogen content. In general, D. stramonium compensated for the relative costs of concurrent mycorrhizal interactions and defoliation; plants that lacked both interactions exhibited the same performance as plants with both types of interactions.

  1. Enrichment of arbuscular mycorrhizal fungi in a contaminated soil after rehabilitation

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    Patrícia Lopes Leal

    Full Text Available Abstract Spore counts, species composition and richness of arbuscular mycorrhizal fungi, and soil glomalin contents were evaluated in a soil contaminated with Zn, Cu, Cd and Pb after rehabilitation by partial replacement of the contaminated soil with non-contaminated soil, and by Eucalyptus camaldulensis planting with and without Brachiaria decumbens sowing. These rehabilitation procedures were compared with soils from contaminated non-rehabilitated area and non-contaminated adjacent soils. Arbuscular mycorrhizal fungi communities attributes were assessed by direct field sampling, trap culture technique, and by glomalin contents estimate. Arbuscular mycorrhizal fungi was markedly favored by rehabilitation, and a total of 15 arbuscular mycorrhizal fungi morphotypes were detected in the studied area. Species from the Glomus and Acaulospora genera were the most common mycorrhizal fungi. Number of spores was increased by as much as 300-fold, and species richness almost doubled in areas rehabilitated by planting Eucalyptus in rows and sowing B. decumbens in inter-rows. Contents of heavy metals in the soil were negatively correlated with both species richness and glomalin contents. Introduction of B. decumbens together with Eucalyptus causes enrichment of arbuscular mycorrhizal fungi species and a more balanced community of arbuscular mycorrhizal fungi spores in contaminated soil.

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

    Energy Technology Data Exchange (ETDEWEB)

    Calvet, C.; Garcia-Figueres, F.; Lovato, P.; Camprubi, A.

    2015-07-01

    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. (Author)

  3. 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.

  4. 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.

  5. Multi-omics approach identifies molecular mechanisms of plant-fungus mycorrhizal interaction

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    Peter E Larsen

    2016-01-01

    Full Text Available In mycorrhizal symbiosis, plant roots form close, mutually beneficial interactions with soil fungi. Before this mycorrhizal interaction can be established however, plant roots must be capable of detecting potential beneficial fungal partners and initiating the gene expression patterns necessary to begin symbiosis. To predict a plant root – mycorrhizal fungi sensor systems, we analyzed in vitro experiments of Populus tremuloides (aspen tree and Laccaria bicolor (mycorrhizal fungi interaction and leveraged over 200 previously published transcriptomic experimental data sets, 159 experimentally validated plant transcription factor binding motifs, and more than 120-thousand experimentally validated protein-protein interactions to generate models of pre-mycorrhizal sensor systems in aspen root. These sensor mechanisms link extracellular signaling molecules with gene regulation through a network comprised of membrane receptors, signal cascade proteins, transcription factors, and transcription factor biding DNA motifs. Modeling predicted four pre-mycorrhizal sensor complexes in aspen that interact with fifteen transcription factors to regulate the expression of 1184 genes in response to extracellular signals synthesized by Laccaria. Predicted extracellular signaling molecules include common signaling molecules such as phenylpropanoids, salicylate, and, jasmonic acid. This multi-omic computational modeling approach for predicting the complex sensory networks yielded specific, testable biological hypotheses for mycorrhizal interaction signaling compounds, sensor complexes, and mechanisms of gene regulation.

  6. Some Root Traits of Barley (Hordeum vulgare L. as Affected by Mycorrhizal Symbiosis under Drought Stress

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    R. Bayani

    2016-05-01

    Full Text Available The effect of drought stress and mycorrhizal symbiosis on the colonization, root and leaf phosphorous content, root and leaf phosphatase activity, root volume and area as well as shoot dry weight of a variety of hulless barley were evaluated using a completely randomized experimental design (CRD with 3 replications. Treatments were three levels of drought stress of 30, 60 and 90% field capacity and two levels of mycorrhizal with and without inoculation. According to the results, the highest value of leaf phosphorous (1.54 mg/g was observed at mycorrhizal symbiosis against severe drought treatment. Root phosphatase activity was highest (297.9 OD min -1 FW-1 at severe drought stress with mycorrhizal symbiosis which in comparison with mild stress in the presence of mycorrhiza showed 16.6 fold increasing. The control and non-mycorrhizal symbiosis treatments had highest root dry weight (0.091 g. The lowest root volume (0.016 cm2 observed at mycorrhizal symbiosis × severe drought treatment. Generally, Inoculation of barley seed with mycorrhiza at severe water stress could transport more phosphorous to shoot, especially leaf via inducing of leaf and root phosphatase activity. Also, in addition to supply of nutrient sources especially phosphorous for plant, mycorrhizal symbiosis could play an important role in withstanding water stress in plant via increasing of root dry weight and area.

  7. [Effect of five fungicides on growth of Glycyrrhiza uralensis and efficiency of mycorrhizal symbiosis].

    Science.gov (United States)

    Li, Peng-ying; Yang, Guang; Zhou, Xiu-teng; Zhou, Liane-yun; Shao, Ai-juan; Chen, Mei-lan

    2015-12-01

    In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins.

  8. 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. © 2012 Max-Planck Society New Phytologist © 2012 New Phytologist Trust.

  9. Functional and genetic diversity of mycorrhizal fungi from single plants of Caladenia formosa (Orchidaceae)

    Science.gov (United States)

    Huynh, Tien T.; Thomson, Richard; Mclean, Cassandra B.; Lawrie, Ann C.

    2009-01-01

    Background and Aims Mycorrhizal associations are essential to the plant kingdom. The largest flowering plant family, the Orchidaceae, relies on mycorrhizal fungi for germination, growth and survival. Evidence suggests varying degrees of fungal-host specificity based on a single fungal isolate from a single plant. This paper shows for the first time the diversity of endophytes colonizing in a single plant over consecutive years and the functional significance of this diversity. Methods Stem-collars of Caladenia formosa were collected in different seasons and years. Mycorrhizal fungi isolated were tested for their efficacy to induce leafing and genetically determined using ITS-RFLP and sequencing. Results Multiple mycorrhizal fungi were repeatedly isolated from a single collar that displayed varying effectiveness in germination percentages and adult leaf length. Additional factors contributed to the isolation of effective mycorrhizal fungi; fungal collection season, year of collection and individual isolates. Surface sterilization only improved the number of isolated mycorrhizal fungi. Dual inoculation did not increase germination. All 59 mycorrhizal fungi effective in germinating seed belonged to one clearly defined ITS (internal transcribed spacer) clade and clustered close to Sebacina vermifera (79–89 % homology). Isolates resulting in the greatest germination were not necessarily those resulting in the greatest survival and growth 1 year after germination. Conclusion Single orchid plants contained multiple mycorrhizal fungal strains of one species that had diverse functional differences. These results suggest that our current knowledge of fungal–host specificity may be incomplete due to experimental and analytical limitations. It also suggests that the long-term effectiveness of a mycorrhizal fungus or fungi could only be found by germination and longer-term growth tests rather than genetically. PMID:19561011

  10. Monitoring CO2emissions to gain a dynamic view of carbon allocation to arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Slavíková, Renata; Püschel, David; Janoušková, Martina; Hujslová, Martina; Konvalinková, Tereza; Gryndlerová, Hana; Gryndler, Milan; Weiser, Martin; Jansa, Jan

    2017-01-01

    Quantification of carbon (C) fluxes in mycorrhizal plants is one of the important yet little explored tasks of mycorrhizal physiology and ecology. 13 CO 2 pulse-chase labelling experiments are increasingly being used to track the fate of C in these plant-microbial symbioses. Nevertheless, continuous monitoring of both the below- and aboveground CO 2 emissions remains a challenge, although it is necessary to establish the full C budget of mycorrhizal plants. Here, a novel CO 2 collection system is presented which allows assessment of gaseous CO 2 emissions (including isotopic composition of their C) from both belowground and shoot compartments. This system then is used to quantify the allocation of recently fixed C in mycorrhizal versus nonmycorrhizal Medicago truncatula plants with comparable biomass and mineral nutrition. Using this system, we confirmed substantially greater belowground C drain in mycorrhizal versus nonmycorrhizal plants, with the belowground CO 2 emissions showing large variation because of fluctuating environmental conditions in the glasshouse. Based on the assembled 13 C budget, the C allocation to the mycorrhizal fungus was between 2.3% (increased 13 C allocation to mycorrhizal substrate) and 2.9% (reduction of 13 C allocation to mycorrhizal shoots) of the plant gross photosynthetic production. Although the C allocation to shoot respiration (measured during one night only) did not differ between the mycorrhizal and nonmycorrhizal plants under our experimental conditions, it presented a substantial part (∼10%) of the plant C budget, comparable to the amount of CO 2 released belowground. These results advocate quantification of both above- and belowground CO 2 emissions in future studies.

  11. The role of mycorrhizal fungi in integrated carbon and nitrogen cycles

    Science.gov (United States)

    Rebel, Karin; Phillips, Rich; Fransson, Petra; Brzostek, Eddie; Wassen, Martin

    2013-04-01

    Understanding the role of terrestrial ecosystems in removing carbon dioxide (CO2) from the atmosphere remains one of the fundamental challenges to predicting future changes in the Earth's climate. Will forests continue to sequester carbon (C) under rising atmospheric CO2 and nitrogen (N) deposition, or will the capacity of trees to build new biomass be constrained by lack of nutrients? Recent research shows that not all tree species react similarly to N-deposition; differences are found in growth rates, survival and C-storage. Mycorrhizal fungi are an important link in coupling the C and N cycles and are critical for tree growth. Mycorrhizal fungi form mutualistic relationships, receiving carbohydrates from their plant hosts and in return enhancing the supply of critical nutrients. The two most abundant mycorrhizal associations are arbuscular mycorrhizae (AM) and ectomycorrhizae (EM), both having different mechanisms of N acquisition, which may explain observed differences in tree species response to N-deposition. Changing environmental variables influence mycorrhizal fungi. Increasing CO2 concentration increases mycorrhizal abundance, growth and plant C allocation belowground. However, the effect of N-deposition on mycorrhizae is less clear. N-deposition can have positive, neutral or negative effects on mycorrhizal abundance and growth. It has been hypothesized that the effect of N-deposition on mycorrhizal growth depends on initial soil nutrient status. This soil nutrient status may also determine the nature of the mycorrhizal relationship to the tree, where in nutrient poor conditions, they could be more beneficial than in nutrient rich conditions. In this research, we extend the hypothesis to include growth of trees associated with either EM or AM, as a function of increasing nitrogen deposition and soil nutrient status. Therefore, we take into account the C-cost and the N-gain of the mycorrhizal fungi for the tree in the different nutrient stages.

  12. Functional analysis of duplicated Symbiosis Receptor Kinase (SymRK) genes during nodulation and mycorrhizal infection in soybean (Glycine max).

    Science.gov (United States)

    Indrasumunar, Arief; Wilde, Julia; Hayashi, Satomi; Li, Dongxue; Gresshoff, Peter M

    2015-03-15

    Association between legumes and rhizobia results in the formation of root nodules, where symbiotic nitrogen fixation occurs. The early stages of this association involve a complex of signalling events between the host and microsymbiont. Several genes dealing with early signal transduction have been cloned, and one of them encodes the leucine-rich repeat (LRR) receptor kinase (SymRK; also termed NORK). The Symbiosis Receptor Kinase gene is required by legumes to establish a root endosymbiosis with Rhizobium bacteria as well as mycorrhizal fungi. Using degenerate primer and BAC sequencing, we cloned duplicated SymRK homeologues in soybean called GmSymRKα and GmSymRKβ. These duplicated genes have high similarity of nucleotide (96%) and amino acid sequence (95%). Sequence analysis predicted a malectin-like domain within the extracellular domain of both genes. Several putative cis-acting elements were found in promoter regions of GmSymRKα and GmSymRKβ, suggesting a participation in lateral root development, cell division and peribacteroid membrane formation. The mutant of SymRK genes is not available in soybean; therefore, to know the functions of these genes, RNA interference (RNAi) of these duplicated genes was performed. For this purpose, RNAi construct of each gene was generated and introduced into the soybean genome by Agrobacterium rhizogenes-mediated hairy root transformation. RNAi of GmSymRKβ gene resulted in an increased reduction of nodulation and mycorrhizal infection than RNAi of GmSymRKα, suggesting it has the major activity of the duplicated gene pair. The results from the important crop legume soybean confirm the joint phenotypic action of GmSymRK genes in both mycorrhizal and rhizobial infection seen in model legumes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  13. A biological market analysis of the plant-mycorrhizal symbiosis.

    Science.gov (United States)

    Wyatt, Gregory A K; Kiers, E Toby; Gardner, Andy; West, Stuart A

    2014-09-01

    It has been argued that cooperative behavior in the plant-mycorrhizal mutualism resembles trade in a market economy and can be understood using economic tools. Here, we assess the validity of this "biological market" analogy by investigating whether a market mechanism--that is, competition between partners over the price at which they provide goods--could be the outcome of natural selection. Then, we consider the conditions under which this market mechanism is sufficient to maintain mutualistic trade. We find that: (i) as in a market, individuals are favored to divide resources among trading partners in direct relation to the relative amount of resources received, termed linear proportional discrimination; (ii) mutualistic trade is more likely to be favored when individuals are able to interact with more partners of both species, and when there is a greater relative difference between the species in their ability to directly acquire different resources; (iii) if trade is favored, then either one or both species is favored to give up acquiring one resource directly, and vice versa. We then formulate testable predictions as to how environmental changes and coevolved responses of plants and mycorrhizal fungi will influence plant fitness (crop yields) in agricultural ecosystems. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  14. Phylogenetic constrains on mycorrhizal specificity in eight Dendrobium (Orchidaceae) species.

    Science.gov (United States)

    Xing, Xiaoke; Ma, Xueting; Men, Jinxin; Chen, Yanhong; Guo, Shunxing

    2017-05-01

    Plant phylogeny constrains orchid mycorrhizal (OrM) fungal community composition in some orchids. Here, we investigated the structures of the OrM fungal communities of eight Dendrobium species in one niche to determine whether similarities in the OrM fungal communities correlated with the phylogeny of the host plants and whether the Dendrobium-OrM fungal interactions are phylogenetically conserved. A phylogeny based on DNA data was constructed for the eight coexisting Dendrobium species, and the OrM fungal communities were characterized by their roots. There were 31 different fungal lineages associated with the eight Dendrobium species. In total, 82.98% of the identified associations belonging to Tulasnellaceae, and a smaller proportion involved members of the unknown Basidiomycota (9.67%). Community analyses revealed that phylogenetically related Dendrobium tended to interact with a similar set of Tulasnellaceae fungi. The interactions between Dendrobium and Tulasnellaceae fungi were significantly influenced by the phylogenetic relationships among the Dendrobium species. Our results provide evidence that the mycorrhizal specificity in the eight coexisting Dendrobium species was phylogenetically conserved.

  15. Metal accumulation and detoxification mechanisms in mycorrhizal Betula pubescens.

    Science.gov (United States)

    Fernández-Fuego, D; Bertrand, A; González, A

    2017-12-01

    Metal detoxification in plants is a complex process that involves different mechanisms, such as the retention of metals to the cell wall and their chelation and subsequent compartmentalization in plant vacuoles. In order to identify the mechanisms involved in metal accumulation and tolerance in Betula pubescens, as well as the role of mycorrhization in these processes, mycorrhizal and non-mycorrhizal plants were grown in two industrial soils with contrasting concentrations of heavy metals. Mycorrhization increased metal uptake at low metal concentrations in the soil and reduced it at high metal concentrations, which led to an enhanced growth and biomass production of the host when growing in the most polluted soil. Our results suggest that the sequestration on the cell wall is the main detoxification mechanism in white birch exposed to acute chronic metal-stress, while phytochelatins play a role mitigating metal toxicity inside the cells. Given its high Mn and Zn root-to-shoot translocation rate, Betula pubescens is a very promising species for the phytoremediation of soils polluted with these metals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Influência de substratos e fungos micorrízicos arbusculares no desenvolvimento vegetativo do porta-enxerto flying dragon. (Poncirus trifoliata, var. montruosa Swing. Influence of growing media and arbuscular mycorrhizal fungi in the vegetative development of flying dragon (Poncirus trifoliata, var. monstruosa Swing. rootstock

    Directory of Open Access Journals (Sweden)

    Paulo Vitor Dutra de Souza

    2005-08-01

    Full Text Available O presente estudo teve por objetivos avaliar o efeito da composição do substrato e da inoculação de duas espécies de fungos micorrízicos arbusculares (FMA (Glomus clarum e Acaulospora scrobiculata sobre o desenvolvimento vegetativo, o conteúdo em substâncias de reserva nos tecidos e a percentagem de colonização radicular por FMA no porta-enxerto Flying dragon (Poncirus trifoliata, var. monstruosa Swing. Os tratamentos consistiram de dois substratos: S1= solo + areia (1:1; v:v e S2 = solo + areia + resíduo decomposto de casca de acácia-negra (2:2:1; v:v:v, ambos com e sem inoculação isolada de duas espécies de FMA (G. clarum e A. scrobiculata. Constatou-se que a adição de resíduo decomposto de casca de acácia-negra melhorou as características químicas e físicas do substrato, permitindo um maior desenvolvimento vegetativo e acúmulo de substâncias de reserva às plantas de Flying dragon em relação ao substrato solo + areia. A eficiência da simbiose foi variável com o substrato e com a espécie de FMA, onde o efeito positivo dos FMA foi notado apenas no substrato solo + areia, mais pobre nutricionalmente, sendo A. scrobiculata a espécie mais eficiente.The present study had the aim of evaluating the effects of substrate composition and the inoculation of two species of arbuscular mycorrhizal fungi (AMF (Glomus clarum and Acaulospora scrobiculata on the vegetative development, carbohydrate contents and percentage of radicular colonization settling by AMF in Flying Dragon (Poncirus trifoliata, var. monstruosa Swing. rootstock. The treatments consisted of two substrates: S1 = soil + sand (1:1; v: v, and S2 = soil + sand + decomposed residue of acacia, (2:2:1; v: v: v. Both treatments were submitted to inoculation with two species of AMF (G. clarum e A. scrobiculata and no inoculation. The addition of decomposed residue of acacia bark in S2, improved the chemical and physical properties of the substrate, resulting in a better

  17. The survival successes of mycorrhizal and nonmycorrhizal ...

    African Journals Online (AJOL)

    In the detailed planting applications of landscape architecture, the negativities created by insufficiencies in ecological conditions and care interferences create effects that increase economical losses. On the other hand, the drought in summer is an important problem. As a result, the plant development decreases, the ...

  18. Effects of Pseudomonas fluorescens on the Water Parameters of Mycorrhizal and Non-Mycorrhizal Seedlings of Pinus halepensis

    Directory of Open Access Journals (Sweden)

    José A. Saiz de Omeñaca

    2013-08-01

    Full Text Available Inoculation of forest seedlings with mycorrhizal fungi and rhizobacteria can improve the morphological and physiological qualities of plants, especially those used for regeneration of arid areas. In this paper, under standard nursery conditions, Aleppo pine seedlings were inoculated with Pseudomonas fluorescens CECT 5281 rhizobacteria. Some of these seedlings were also inoculated with the ectomycorrhizal fungus Pisolithus tinctorius. Five months after the inoculations, we examined the growth, water parameters (osmotic potential at full turgor [Ψπfull], osmotic potential at zero turgor [Ψπ0], and the tissue modulus of elasticity near full turgor [Emax], mycorrhizal colonisation, and concentration of macronutrients (N, P, K, Ca and Mg in the seedlings. Subsequently, a trial was conducted to assess the root growth potential. P. fluorescens CECT 5281 decreased the cellular osmotic potential of P. halepensis seedlings but increased its elasticity. P. tinctorius + P. fluorescens caused osmotic adjustment at zero turgor and increased tissue elasticity, which improved tolerance to water stress. All inoculations improved the growth and nutrition of the seedlings but caused non-significant effects on root growth potential. The co-inoculation Pisolithus tinctorius + Pseudomonas fluorescens at the nursery may be a suitable technique for producing improved seedling material for restoration purposes.

  19. Stars and symbiosis: microRNA- and microRNA*-mediated transcript cleavage involved in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Devers, Emanuel A; Branscheid, Anja; May, Patrick; Krajinski, Franziska

    2011-08-01

    The majority of plants are able to form the arbuscular mycorrhizal (AM) symbiosis in association with AM fungi. During symbiosis development, plant cells undergo a complex reprogramming resulting in profound morphological and physiological changes. MicroRNAs (miRNAs) are important components of the regulatory network of plant cells. To unravel the impact of miRNAs and miRNA-mediated mRNA cleavage on root cell reprogramming during AM symbiosis, we carried out high-throughput (Illumina) sequencing of small RNAs and degradome tags of Medicago truncatula roots. This led to the annotation of 243 novel miRNAs. An increased accumulation of several novel and conserved miRNAs in mycorrhizal roots suggest a role of these miRNAs during AM symbiosis. The degradome analysis led to the identification of 185 root transcripts as mature miRNA and also miRNA*-mediated mRNA cleavage targets. Several of the identified miRNA targets are known to be involved in root symbioses. In summary, the increased accumulation of specific miRNAs and the miRNA-mediated cleavage of symbiosis-relevant genes indicate that miRNAs are an important part of the regulatory network leading to symbiosis development.

  20. 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

    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

  1. 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

  2. Saprotrophic fungal mycorrhizal symbionts in achlorophyllous orchids: finding treasures among the 'molecular scraps'?

    Science.gov (United States)

    Selosse, Marc-André; Martos, Florent; Perry, Brian A; Padamsee, Mahajabeen; Roy, Mélanie; Pailler, Thierry

    2010-04-01

    Mycoheterotrophic plants are achlorophyllous plants that obtain carbon from their mycorrhizal fungi. They are usually considered to associate with fungi that are (1) specific of each mycoheterotrophic species and (2) mycorrhizal on surrounding green plants, which are the ultimate carbon source of the entire system. Here we review recent works revealing that some mycoheterotrophic plants are not fungal-specific, and that some mycoheterotrophic orchids associate with saprophytic fungi. A re-examination of earlier data suggests that lower specificity may be less rare than supposed in mycoheterotrophic plants. Association between mycoheterotrophic orchids and saprophytic fungi arose several times in the evolution of the two partners. We speculate that this indirectly illustrates why transition from saprotrophy to mycorrhizal status is common in fungal evolution. Moreover, some unexpected fungi occasionally encountered in plant roots should not be discounted as 'molecular scraps', since these facultatively biotrophic encounters may evolve into mycorrhizal symbionts in some other plants.

  3. Plant-soil feedbacks and mycorrhizal type influence temperate forest population dynamics.

    Science.gov (United States)

    Bennett, Jonathan A; Maherali, Hafiz; Reinhart, Kurt O; Lekberg, Ylva; Hart, Miranda M; Klironomos, John

    2017-01-13

    Feedback with soil biota is an important determinant of terrestrial plant diversity. However, the factors regulating plant-soil feedback, which varies from positive to negative among plant species, remain uncertain. In a large-scale study involving 55 species and 550 populations of North American trees, the type of mycorrhizal association explained much of the variation in plant-soil feedbacks. In soil collected beneath conspecifics, arbuscular mycorrhizal trees experienced negative feedback, whereas ectomycorrhizal trees displayed positive feedback. Additionally, arbuscular mycorrhizal trees exhibited strong conspecific inhibition at multiple spatial scales, whereas ectomycorrhizal trees exhibited conspecific facilitation locally and less severe conspecific inhibition regionally. These results suggest that mycorrhizal type, through effects on plant-soil feedbacks, could be an important contributor to population regulation and community structure in temperate forests. Copyright © 2017, American Association for the Advancement of Science.

  4. Growth and nutrition of eucalyptus clones seedlings inoculated with mycorrhizal fungi

    National Research Council Canada - National Science Library

    Francisco deSousa Lima; Carla daSilva Sousa

    2014-01-01

    ... (five fungal species and five eucalyptus clones), with five replications. In general, the mycorrhizal symbiosis significantly increased the growth and nutrition of eucalyptus seedlings, when compared to the non-inoculated seedlings...

  5. Effects of Microbiotic Soil Crust Organisms and Mycorrhizal Fungi on Seedling Growth of Blackbrush (Coleogyne ramosissima)

    National Research Council Canada - National Science Library

    Pendleton, Rosemary

    1999-01-01

    .... A series of experiments conducted from 1993 to 1997 tested the effect of inoculation with arbuscular mycorrhizal fungi on the growth of young blackbrush seedlings under a variety of soil nutrient conditions...

  6. Three-way interactions among mutualistic mycorrhizal fungi, plants, and plant enemies: hypotheses and synthesis.

    Science.gov (United States)

    Bennett, Alison E; Alers-Garcia, Janice; Bever, James D

    2006-02-01

    A number of studies have shown that an association with mycorrhizal fungi can alter the outcome of interactions between plants and their enemies. While the directions of these effects vary, their strength suggests the need for greater attention to multispecies interactions among plant enemies, plants, and mycorrhizal fungi. We recognize that mycorrhizal fungi could effect plant enemies by improving plant nutrition, modifying plant tolerance, or modifying plant defenses. In addition, mycorrhizal fungi could directly interfere with pathogen infection, herbivory, or parasitism by occupying root space. We formalize these alternative outcomes of multispecies interactions and explore the long-term dynamics of the plant-enemy interactions based on these different scenarios using a general model of interactions between plants and plant enemies. We then review the literature in terms of the assumptions of the alternative mechanisms and the predictions of these models. Through this effort, we identify new directions in the study of tritrophic interactions between enemies, plants, and soil mutualists.

  7. Effects of ammonium and nitrate on mycorrhizal seedlings of Pinus sylvestris.

    NARCIS (Netherlands)

    Termorshuizen, A.J.; Ket, P.C.

    1991-01-01

    The effects of ammonium sulphate and sodium nitrate on Pinus sylvestris seedlings inoculated with Paxillus involutus and Suillus bovinus were investigated. Weekly fertilization (26 weeks) positively affected the plant dry weight, but inhibited the mycorrhizal formation and decreased the root

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

    National Research Council Canada - National Science Library

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

    2012-01-01

    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...

  9. The Laccaria and Tuber Genomes Reveal Unique Signatures of Mycorrhizal Symbiosis Evolution (2010 JGI User Meeting)

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Steve

    2010-03-24

    Francis Martin from the French agricultural research institute INRA talks on how "The Laccaria and Tuber genomes reveal unique signatures of mycorrhizal symbiosis evolution" on March 24, 2010 at the 5th Annual DOE JGI User Meeting

  10. Mycorrhizal diversity in Apostasia (Orchidaceae) indicates the origin and evolution of orchid mycorrhiza

    National Research Council Canada - National Science Library

    Yukawa, Tomohisa; Ogura-Tsujita, Yuki; Shefferson, Richard P; Yokoyama, Jun

    2009-01-01

    ... University, Yamagata 990-8560 Japan ABSTRACT We demonstrated that "orchid mycorrhiza," a specialized mycorrhizal type, appeared in the common ancestor of the largest plant family Orchidaceae and that the...

  11. 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.

  12. Mycorrhizal fungi influence on silver uptake and membrane protein gene expression following silver nanoparticle exposure

    Energy Technology Data Exchange (ETDEWEB)

    Noori, Azam [State University of New York, College of Environmental Science and Forestry (United States); White, Jason C. [Connecticut Agricultural Experiment Station (United States); Newman, Lee A., E-mail: lanewman@esf.edu [State University of New York, College of Environmental Science and Forestry (United States)

    2017-02-15

    The rapid growth of nanotechnology and the high demand for nanomaterial use have greatly increased the risk of particle release into the environment. Understanding nanomaterial interactions with crop species and their associated microorganisms is critical to food safety and security. In the current study, tomato was inoculated with mycorrhizal fungi and subsequently exposed to 12, 24, or 36 mg/kg of 2- or 15-nm silver nanoparticles (Ag-NPs). Mycorrhizal (M) and non-mycorrhizal (NM) tomatoes exposed to 36 mg/kg of 2-nm Ag-NPs accumulated 1300 and 1600 μg/g silver in their tissues, respectively. Mycorrhizal plants accumulated 14% less silver compared to non-mycorrhizal plants. To begin to understand the mechanisms by which plants accumulate NPs, the expression of two aquaporin channel genes, the plasma membrane intrinsic protein (PIP) and the tonoplast membrane intrinsic protein (TIP), and one potassium channel (KC) gene were studied. In non-mycorrhizal plants, the expression of KC, PIP, and TIP was eight, five, and nine times higher than the control, respectively. These expressions for mycorrhizal plants were 5.8, 3.5, and 2 times higher than controls, respectively. The expression of KC and PIP, which are located on the plasma membrane, was 3.5 and 2.5, respectively, times higher than TIP, which is located on the tonoplast. PIP expression was significantly higher in NM tomatoes exposed to 12 mg/kg of 2-nm Ag-NPs compared to M plants. These results show that mycorrhizal colonization decreases Ag accumulation in NP-exposed plants and also moderates changes in expression level of membrane transport proteins.

  13. Dioecious species and arbuscular mycorrhizal symbioses: The case of Antennaria dioica

    OpenAIRE

    Vega-Frutis, Rocío; Varga, Sandra; Kytöviita, Minna-Maarit

    2013-01-01

    Sex-specific interactions with herbivores and pollinators have been observed in female and male plants of dioecious species. However, only a limited number of studies have revised sex-specific patterns in mycorrhizal symbiosis. To test whether female and male plants of Antennaria dioica differ in their relationship with arbuscular mycorrhizal (AM) fungi, we examined the temporal and spatial variation in AM fungi in female, male and non-reproductive A. dioica plants in three natural population...

  14. Seasonal Dynamics of Arbuscular Mycorrhizal Fungal Communities in Roots in a Seminatural Grassland▿ †

    OpenAIRE

    Santos-González, Juan C.; Finlay, Roger D.; Tehler, Anders

    2007-01-01

    Symbiotic arbuscular mycorrhizal fungi (AMF) have been shown to influence both the diversity and productivity of grassland plant communities. These effects have been postulated to depend on the differential effects of individual mycorrhizal taxa on different plant species; however, so far there are few detailed studies of the dynamics of AMF colonization of different plant species. In this study, we characterized the communities of AMF colonizing the roots of two plant species, Prunella vulga...

  15. Mycorrhizal status of an ozone-sensitive poplar clone treated with the antiozonant ethylene diurea

    OpenAIRE

    Katanić, Marina; Paoletti, Elena; Orlović, Saša; Grebenc, Tine; Kraigher, Hojka

    2014-01-01

    The antiozonant ethylene diurea is proven to prevent growth reductions in forest trees induced by ozone. The community of mycorrhizal fungi could be useful indicator of environmental stress. In this study, response of mycorrhizal fungi and fine roots to a 4-year exposure to ambient ozone and treatment with antiozonant was investigated in ozone-sensitive poplar clone under field conditions. The community of ectomycorrhizal fungi and root length colonization with ectomycorrhizal, arbuscular myc...

  16. Growth response of different species of Ziziphus to inoculation with arbuscular mycorrhizal fungi

    OpenAIRE

    Thioye, B.; Mania, S.; Kane, A.; Ndiaye, C.; Soule, A. O.; Falls, D.; Duponnois, Robin; Sylla, S. N.; Ba, A. M.

    2017-01-01

    Introduction - Many of species of Ziziphus are underutilized crops despite their potential interests in agroforestry systems. Except for Ziziphus mauritiana, the effectiveness of arbuscular mycorrhizal fungi (AMF) on growth and mineral nutrition of Ziziphus spp. is not known. The aim of our study was to evaluate the mycorrhizal dependency (MD) of Ziziphus spp. in greenhouse conditions. [br/] Materials and methods - Three isolates of AMF were used: Rhizophagus irregularis isolate IR27, Funn...

  17. Mycorrhizal fungi influence on silver uptake and membrane protein gene expression following silver nanoparticle exposure

    Science.gov (United States)

    Noori, Azam; White, Jason C.; Newman, Lee A.

    2017-02-01

    The rapid growth of nanotechnology and the high demand for nanomaterial use have greatly increased the risk of particle release into the environment. Understanding nanomaterial interactions with crop species and their associated microorganisms is critical to food safety and security. In the current study, tomato was inoculated with mycorrhizal fungi and subsequently exposed to 12, 24, or 36 mg/kg of 2- or 15-nm silver nanoparticles (Ag-NPs). Mycorrhizal (M) and non-mycorrhizal (NM) tomatoes exposed to 36 mg/kg of 2-nm Ag-NPs accumulated 1300 and 1600 μg/g silver in their tissues, respectively. Mycorrhizal plants accumulated 14% less silver compared to non-mycorrhizal plants. To begin to understand the mechanisms by which plants accumulate NPs, the expression of two aquaporin channel genes, the plasma membrane intrinsic protein (PIP) and the tonoplast membrane intrinsic protein (TIP), and one potassium channel (KC) gene were studied. In non-mycorrhizal plants, the expression of KC, PIP, and TIP was eight, five, and nine times higher than the control, respectively. These expressions for mycorrhizal plants were 5.8, 3.5, and 2 times higher than controls, respectively. The expression of KC and PIP, which are located on the plasma membrane, was 3.5 and 2.5, respectively, times higher than TIP, which is located on the tonoplast. PIP expression was significantly higher in NM tomatoes exposed to 12 mg/kg of 2-nm Ag-NPs compared to M plants. These results show that mycorrhizal colonization decreases Ag accumulation in NP-exposed plants and also moderates changes in expression level of membrane transport proteins.

  18. 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

    precipitation leached through the soil, or indoor at constant moisture) with or without 9% (w/w) chopped wheat straw plus mineral N. Then the soils were partially sterilized and placed in two-compartment pots where mycorrhizal or non-mycorrhizal cucumber plants were grown in one root compartment (RC), and soils...... have influenced alkaline phosphatase excreted by other microorganisms, probably through competition for nutrients. Phosphatase activity was not correlated with the concentration of labile organic P in soil extracts....

  19. Bioactive and chemical properties of edible mycorrhizal mushrooms from Northeast Portugal

    OpenAIRE

    REIS, F. S.; Sandrina A. Heleno; Barros, Lillian; Sousa, Maria João; Martins, Anabela; Santos-Buelga, Celestino; Isabel C. F. R. Ferreira

    2011-01-01

    Mushrooms are widely appreciated all over the world for their nutritional properties1 and pharmacological value as sources of important bioactive compounds.2,3 Mycorrhizal macrofungi associate with plant roots constituting a symbiotic relationship, beneficial for both plant and fungus. In the present work five edible mycorrhizal species (Amanita caesarea, Cortinarius anomalus, Cortinarius violaceus, Lactarius volemus and Suillus luteus) from Northeast Portugal were studied for their bioac...

  20. Growth and nutrition of eucalyptus clones seedlings inoculated with mycorrhizal fungi

    OpenAIRE

    Francisco de Sousa Lima; Carla da Silva Sousa

    2014-01-01

    Eucalyptus is one of the most planted forest species, in Brazil, due to its rapid growth and high economic yield. Arbuscular mycorrhizal fungi improve the seedlings nutritional and phytosanitary status, besides increasing their resistance to biotic and abiotic stress. This study aimed to evaluate the effect of inoculation with arbuscular mycorrhizal fungi species on the growth and nutrition of different eucalyptus clones seedlings. The experiment was conducted under greenhouse conditions, in ...

  1. Arbuscular Mycorrhizal Fungi Promote the Growth of Ceratocarpus arenarius (Chenopodiaceae) with No Enhancement of Phosphorus Nutrition

    OpenAIRE

    Zhang, Tao; Shi, Ning; Bai, Dengsha; Chen, Yinglong; Feng, Gu

    2012-01-01

    The mycorrhizal status of plants in the Chenopodiaceae is not well studied with a few controversial reports. This study examined arbuscular mycorrhizal (AM) colonization and growth response of Ceratocarpus arenarius in the field and a greenhouse inoculation trial. The colonization rate of AM fungi in C. arenarius in in-growth field cores was low (around 15%). Vesicles and intraradical hyphae were present during all growth stages, but no arbuscules were observed. Sequencing analysis of the lar...

  2. Mycorrhizal specificity does not limit the distribution of an endangered orchid species.

    Science.gov (United States)

    Waud, Michael; Brys, Rein; Van Landuyt, Wouter; Lievens, Bart; Jacquemyn, Hans

    2017-03-01

    What factors determine the distribution of a species is a central question in ecology and conservation biology. In general, the distribution of plant species is assumed to be controlled by dispersal or environmentally controlled recruitment. For plant species which are critically dependent on mycorrhizal symbionts for germination and seedling establishment, specificity in mycorrhizal associations and availability of suitable mycorrhizal fungi can be expected to have a major impact on successful colonization and establishment and thus ultimately on a species distribution. We combined seed germination experiments with soil analyses and fungal assessments using 454 amplicon pyrosequencing to test the relative importance of dispersal limitation, mycorrhizal availability and local growth conditions on the distribution of the orchid species Liparis loeselii, which, despite being widely distributed, is rare and endangered in Europe. We compared local soil conditions, seed germination and mycorrhizal availability in the soil between locations in northern Belgium and France where L. loeselii occurs naturally and locations where conditions appear suitable, but where adults of the species are absent. Our results indicated that mycorrhizal communities associating with L. loeselii varied among sites and plant life cycle stages, but the observed variations did not affect seed germination, which occurred regardless of current L. loeselii presence and was significantly affected by soil moisture content. These results indicate that L. loeselii is a mycorrhizal generalist capable of opportunistically associating with a variety of fungal partners to induce seed germination. They also indicate that availability of fungal associates is not necessarily the determining factor driving the distribution of mycorrhizal plant species. © 2017 John Wiley & Sons Ltd.

  3. NADPH oxidases in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Belmondo, Simone; Calcagno, Cristina; Genre, Andrea; Puppo, Alain; Pauly, Nicolas; Lanfranco, Luisa

    2016-01-01

    Plant NADPH oxidases are the major source of reactive oxygen species (ROS) that plays key roles as both signal and stressor in several plant processes, including defense responses against pathogens. ROS accumulation in root cells during arbuscular mycorrhiza (AM) development has raised the interest in understanding how ROS-mediated defense programs are modulated during the establishment of this mutualistic interaction. We have recently analyzed the expression pattern of 5 NADPH oxidase (also called RBOH) encoding genes in Medicago truncatula, showing that only one of them (MtRbohE) is specifically upregulated in arbuscule-containing cells. In line with this result, RNAi silencing of MtRbohE generated a strong alteration in root colonization, with a significant reduction in the number of arbusculated cells. On this basis, we propose that MtRBOHE-mediated ROS production plays a crucial role in the intracellular accommodation of arbuscules.

  4. MycoDB, a global database of plant response to mycorrhizal fungi

    Science.gov (United States)

    Chaudhary, V. Bala; Rúa, Megan A.; Antoninka, Anita; Bever, James D.; Cannon, Jeffery; Craig, Ashley; Duchicela, Jessica; Frame, Alicia; Gardes, Monique; Gehring, Catherine; Ha, Michelle; Hart, Miranda; Hopkins, Jacob; Ji, Baoming; Johnson, Nancy Collins; Kaonongbua, Wittaya; Karst, Justine; Koide, Roger T.; Lamit, Louis J.; Meadow, James; Milligan, Brook G.; Moore, John C.; Pendergast, Thomas H., IV; Piculell, Bridget; Ramsby, Blake; Simard, Suzanne; Shrestha, Shubha; Umbanhowar, James; Viechtbauer, Wolfgang; Walters, Lawrence; Wilson, Gail W. T.; Zee, Peter C.; Hoeksema, Jason D.

    2016-05-01

    Plants form belowground associations with mycorrhizal fungi in one of the most common symbioses on Earth. However, few large-scale generalizations exist for the structure and function of mycorrhizal symbioses, as the nature of this relationship varies from mutualistic to parasitic and is largely context-dependent. We announce the public release of MycoDB, a database of 4,010 studies (from 438 unique publications) to aid in multi-factor meta-analyses elucidating the ecological and evolutionary context in which mycorrhizal fungi alter plant productivity. Over 10 years with nearly 80 collaborators, we compiled data on the response of plant biomass to mycorrhizal fungal inoculation, including meta-analysis metrics and 24 additional explanatory variables that describe the biotic and abiotic context of each study. We also include phylogenetic trees for all plants and fungi in the database. To our knowledge, MycoDB is the largest ecological meta-analysis database. We aim to share these data to highlight significant gaps in mycorrhizal research and encourage synthesis to explore the ecological and evolutionary generalities that govern mycorrhizal functioning in ecosystems.

  5. Enhancement of clover growth by inoculation of P-solubilizing fungi and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Souchie, Edson L; Azcón, Rosario; Barea, Jose M; Silva, Eliane M R; Saggin-Júnior, Orivaldo J

    2010-09-01

    This study evaluated the synergism between several P-solubilizing fungi isolates and arbuscular mycorrhizal fungi to improve clover ( Trifolium pratense) growth in the presence of Araxá apatite. Clover was sown directly in plastic pots with 300g of sterilized washed sand, vermiculite and sepiolite 1:1:1 (v:v:v) as substrate, and grown in a controlled environment chamber. The substrate was fertilized with 3 g L(-1) of Araxá apatite. A completely randomized design, in 8×2 factorial scheme (eight P-solubilizing fungi treatments with or without arbuscular mycorrhizal fungi)and four replicates were used. The P-solubilizing fungi treatments consisted of five Brazilian P-solubilizing fungi isolates (PSF 7, 9, 20, 21 and 22), two Spanish isolates ( Aspergillus niger and the yeast Yarowia lipolytica) and control (non-inoculated treatment). The greatest clover growth rate was recorded when Aspergillus niger and PSF 21 were co-inoculated with arbuscular mycorrhizal fungi. Aspergillus niger, PSF 7 and PSF 21 were the most effective isolates on increasing clover growth in the presence of arbuscular mycorrhizal fungi. Greater mycorrhizal colonization resulted in greater clover growth rate in most PSF treatments. PSF 7 was the best isolate to improve the establishment of mycorrhizal and rhizobia symbiosis.

  6. Leucanthemum vulgare lam. germination, growth and mycorrhizal symbiosis under crude oil contamination.

    Science.gov (United States)

    Noori, Azam Sadat; Maivan, Hassan Zare; Alaie, Ebrahim

    2014-01-01

    Oil contamination of soil limits plants' access to water and nutrients. Leucanthemum vulgare colonized by mycorrhizae could provide an effective tool in remedying oil contamination. Seeds of L. vulgare were planted in pots containing soil mixed with petroleum at 0, 2.5, 5, 7.5, and 10% w/w and propagules of mycorrhizal fungi. Plants were grown under ambient conditions for 16 weeks. Seed germination data were collected weekly for three weeks. Mycorrhizal percentage, spore counts, length and weight of roots and shoots were determined after harvesting. Results showed significant differences in seed germination rates between oil-treated, mycorrhizal and non-mycorrhizal plants. The overall germination rate was greater at 7.5% w/w crude oil contamination (p = 0.05) in mycorrhizal and non-mycorrhizal pots with significant differences between their respective Root:Shoot ratios (both length and weight). Results of this research showed L. vulgare could be germinated and grown in crude oil contaminated soils and could be used to augment plant establishment as part of phytoremediation practices.

  7. Soil Mesofauna Response to Cover Crops and Mycorrhizal Inoculated Plantation on Limestone Quarry Revegetation

    Directory of Open Access Journals (Sweden)

    Retno Prayudyaningsih

    2016-06-01

    Full Text Available Cover crops establishment followed by mycorrhizal inoculated tree plantation accelerate limestone quaryy restoration. Soil mesofauna is a useful indicator for assessing biodiversity recovery, as they are sensitive to human disturbance and involved in ecological processes. In this research, soil mesofauna presence used to evaluate limestone quarry restoration by cover crops and mycorrhizal inoculated tree esatblisment. Soil mesofauna are measured using individual density, species diversity, richness and important value. The study was conducted in four types of areas on limestone postmining lands are open areas/natural conditions without planting, cover crop area, non mycorrhizalinoculated plant area and mycorrhizal-inoculated plant area. The result showed The higher individual density, diversity and species richness of soil mesofauna on cover crops and mycorrhizal inoculated plant area than other areas are indicators of limestone quarry restoration rate. Furthermore the presence of Formicidae family that dominated on cover crops and mycorrhizal inoculated plant area, and emergence of Acari group only on mycorrhizal inoculated area also an indicator of limestone quarry restoration.

  8. Carbon dynamics in mycorrhizal symbioses is linked to carbon costs and phosphorus benefits.

    Science.gov (United States)

    Olsson, Pål Axel; Rahm, Jannice; Aliasgharzad, Nasser

    2010-04-01

    The nutrient and carbon (C) allocation dynamics in mycorrhizal hyphal networks cause variation in costs and benefits for individual plants and fungi and influence the productivity, diversity and C cycling in ecosystems. We manipulated light and phosphorus (P) availability in a pot experiment with Trifolium subterraneum colonised by the arbuscular mycorrhizal (AM) fungus Glomus intraradices. Stable (13)C-labelling was used to trace assimilated CO(2) to the mycorrhizal fungus in roots and soil using compound-specific isotope ratio mass spectrometry. We used the neutral lipid fatty acid 16:1omega5 as a signature for AM fungal storage lipids. Both P and shading reduced the AM fungal lipid accumulation in the intraradical mycelium, while only P reduced the amount of lipids in the extraradical mycelium. Recently assimilated plant C was only allocated to the mycorrhizal fungus to a small extent when plant mycorrhizal benefit was reduced by P fertilization, while increasing the plant C cost by shading did not reduce the C flow to the fungus. These results are of importance for our conception of mycorrhizal dynamics during periods of shade in nature.

  9. The arbuscular mycorrhizal status has an impact on the transcriptome profile and amino acid composition of tomato fruit

    Directory of Open Access Journals (Sweden)

    Salvioli Alessandra

    2012-03-01

    Full Text Available Abstract Background Arbuscular mycorrhizal (AM symbiosis is the most widespread association between plant roots and fungi in natural and agricultural ecosystems. This work investigated the influence of mycorrhization on the economically relevant part of the tomato plant, by analyzing its impact on the physiology of the fruit. To this aim, a combination of phenological observations, transcriptomics (Microarrays and qRT-PCR and biochemical analyses was used to unravel the changes that occur on fruits from Micro-Tom tomato plants colonized by the AM fungus Glomus mosseae. Results Mycorrhization accelerated the flowering and fruit development and increased the fruit yield. Eleven transcripts were differentially regulated in the fruit upon mycorrhization, and the mycorrhiza-responsive genes resulted to be involved in nitrogen and carbohydrate metabolism as well as in regulation and signal transduction. Mycorrhization has increased the amino acid abundance in the fruit from mycorrhizal plants, with glutamine and asparagine being the most responsive amino acids. Conclusions The obtained results offer novel data on the systemic changes that are induced by the establishment of AM symbiosis in the plant, and confirm the work hypothesis that AM fungi may extend their influence from the root to the fruit.

  10. 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

  11. Presymbiotic growth and sporal morphology are affected in the arbuscular mycorrhizal fungus Gigaspora margarita cured of its endobacteria.

    Science.gov (United States)

    Lumini, Erica; Bianciotto, Valeria; Jargeat, Patricia; Novero, Mara; Salvioli, Alessandra; Faccio, Antonella; Bécard, Guillaume; Bonfante, Paola

    2007-07-01

    Some arbuscular mycorrhizal fungi contain endocellular bacteria. In Gigaspora margarita BEG 34, a homogenous population of beta-Proteobacteria is hosted inside the fungal spore. The bacteria, named Candidatus Glomeribacter gigasporarum, are vertically transmitted through fungal spore generations. Here we report how a protocol based on repeated passages through single-spore inocula caused dilution of the initial bacterial population eventually leading to cured spores. Spores of this line had a distinct phenotype regarding cytoplasm organization, vacuole morphology, cell wall organization, lipid bodies and pigment granules. The absence of bacteria severely affected presymbiotic fungal growth such as hyphal elongation and branching after root exudate treatment, suggesting that Ca. Glomeribacter gigasporarum is important for optimal development of its fungal host. Under laboratory conditions, the cured fungus could be propagated, i.e. could form mycorrhizae and sporulate, and can therefore be considered as a stable variant of the wild type. The results demonstrated that - at least for the G. margarita BEG 34 isolate - the absence of endobacteria affects the spore phenotype of the fungal host, and causes delays in the growth of germinating mycelium, possibly affecting its ecological fitness. This cured line is the first manipulated and stable isolate of an arbuscular mycorrhizal fungus.

  12. Nonredundant Regulation of Rice Arbuscular Mycorrhizal Symbiosis by Two Members of the PHOSPHATE TRANSPORTER1 Gene Family[W

    Science.gov (United States)

    Yang, Shu-Yi; Grønlund, Mette; Jakobsen, Iver; Grotemeyer, Marianne Suter; Rentsch, Doris; Miyao, Akio; Hirochika, Hirohiko; Kumar, Chellian Santhosh; Sundaresan, Venkatesan; Salamin, Nicolas; Catausan, Sheryl; Mattes, Nicolas; Heuer, Sigrid; Paszkowski, Uta

    2012-01-01

    Pi acquisition of crops via arbuscular mycorrhizal (AM) symbiosis is becoming increasingly important due to limited high-grade rock Pi reserves and a demand for environmentally sustainable agriculture. Here, we show that 70% of the overall Pi acquired by rice (Oryza sativa) is delivered via the symbiotic route. To better understand this pathway, we combined genetic, molecular, and physiological approaches to determine the specific functions of two symbiosis-specific members of the PHOSPHATE TRANSPORTER1 (PHT1) gene family from rice, ORYsa;PHT1;11 (PT11) and ORYsa;PHT1;13 (PT13). The PT11 lineage of proteins from mono- and dicotyledons is most closely related to homologs from the ancient moss, indicating an early evolutionary origin. By contrast, PT13 arose in the Poaceae, suggesting that grasses acquired a particular strategy for the acquisition of symbiotic Pi. Surprisingly, mutations in either PT11 or PT13 affected the development of the symbiosis, demonstrating that both genes are important for AM symbiosis. For symbiotic Pi uptake, however, only PT11 is necessary and sufficient. Consequently, our results demonstrate that mycorrhizal rice depends on the AM symbiosis to satisfy its Pi demands, which is mediated by a single functional Pi transporter, PT11. PMID:23073651

  13. Nonredundant regulation of rice arbuscular mycorrhizal symbiosis by two members of the phosphate transporter1 gene family.

    Science.gov (United States)

    Yang, Shu-Yi; Grønlund, Mette; Jakobsen, Iver; Grotemeyer, Marianne Suter; Rentsch, Doris; Miyao, Akio; Hirochika, Hirohiko; Kumar, Chellian Santhosh; Sundaresan, Venkatesan; Salamin, Nicolas; Catausan, Sheryl; Mattes, Nicolas; Heuer, Sigrid; Paszkowski, Uta

    2012-10-01

    Pi acquisition of crops via arbuscular mycorrhizal (AM) symbiosis is becoming increasingly important due to limited high-grade rock Pi reserves and a demand for environmentally sustainable agriculture. Here, we show that 70% of the overall Pi acquired by rice (Oryza sativa) is delivered via the symbiotic route. To better understand this pathway, we combined genetic, molecular, and physiological approaches to determine the specific functions of two symbiosis-specific members of the PHOSPHATE TRANSPORTER1 (PHT1) gene family from rice, ORYsa;PHT1;11 (PT11) and ORYsa;PHT1;13 (PT13). The PT11 lineage of proteins from mono- and dicotyledons is most closely related to homologs from the ancient moss, indicating an early evolutionary origin. By contrast, PT13 arose in the Poaceae, suggesting that grasses acquired a particular strategy for the acquisition of symbiotic Pi. Surprisingly, mutations in either PT11 or PT13 affected the development of the symbiosis, demonstrating that both genes are important for AM symbiosis. For symbiotic Pi uptake, however, only PT11 is necessary and sufficient. Consequently, our results demonstrate that mycorrhizal rice depends on the AM symbiosis to satisfy its Pi demands, which is mediated by a single functional Pi transporter, PT11.

  14. Severe plant invasions can increase mycorrhizal fungal abundance and diversity

    DEFF Research Database (Denmark)

    Lekberg, Ylva; Gibbons, Sean; Rosendahl, Søren

    2013-01-01

    Invasions by non-native plants can alter ecosystem functions and reduce native plant diversity, but relatively little is known about their effect on belowground microbial communities. We show that invasions by knapweed (Centaurea stoebe) and leafy spurge (Euphorbia esula, hereafter spurge......)-but not cheatgrass (Bromus tectorum)-support a higher abundance and diversity of symbiotic arbuscular mycorrhizal fungi (AMF) than multi-species native plant communities. The higher AMF richness associated with knapweed and spurge is unlikely due to a co-invasion by AMF, because a separate sampling showed...... that individual native forbs hosted a similar AMF abundance and richness as exotic forbs. Native grasses associated with fewer AMF taxa, which could explain the reduced AMF richness in native, grass-dominated communities. The three invasive plant species harbored distinct AMF communities, and analyses of co...

  15. 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.

  16. Accumulation of apocarotenoids in mycorrhizal roots of leek (Allium porrum).

    Science.gov (United States)

    Schliemann, Willibald; Kolbe, Barbara; Schmidt, Jürgen; Nimtz, Manfred; Wray, Victor

    2008-05-01

    Colonization of the roots of leek (Allium porrum L.) by the arbuscular mycorrhizal fungus Glomus intraradices induced the formation of apocarotenoids, whose accumulation has been studied over a period of 25 weeks. Whereas the increase in the levels of the dominating cyclohexenone derivatives resembles the enhancement of root length colonization, the content of mycorradicin derivatives remains relatively low throughout. Structural analysis of the cyclohexenone derivatives by mass spectrometry and NMR spectroscopy showed that they are mono- and diglycosides of 13-hydroxyblumenol C and blumenol C acylated with 3-hydroxy-3-methyl-glutaric and/or malonic acid. Along with the isolation of three known compounds five others are shown to be hitherto unknown members of the fast-growing family of mycorrhiza-induced cyclohexenone conjugates.

  17. Strigolactones, signals for parasitic plants and arbuscular mycorrhizal fungi.

    Science.gov (United States)

    García-Garrido, J M; Lendzemo, V; Castellanos-Morales, V; Steinkellner, S; Vierheilig, Horst

    2009-09-01

    Although strigolactones play a critical role as rhizospheric signaling molecules for the establishment of arbuscular mycorrhizal (AM) symbiosis and for seed germination of parasitic weeds, scarce data are available about interactions between AM fungi and strigolactones. In the present work, we present background data on strigolactones from studies on their seed germination activity on the parasitic weeds Orobanche and Striga, the importance of nitrogen and phosphorus for this seed germination activity, and what this could mean for AM fungi. We also present results on the susceptibility of plants to AM fungi and the possible involvement of strigolactones in this AM susceptibility and discuss the role of strigolactones for the formation and the regulation of the AM symbiosis as well as the possible implication of these compounds as plant signals in other soil-borne plant-microbe interactions.

  18. Impact of arbuscular mycorrhizal fungi on uranium accumulation by plants

    Energy Technology Data Exchange (ETDEWEB)

    Dupre de Boulois, H. [Universite catholique de Louvain, Unite de Microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium); Joner, E.J. [Bioforsk Soil and Environment, Fredrik A. Dahls vei 20, N-1432 As (Norway); Leyval, C. [LIMOS, Nancy University, CNRS, Faculte des Sciences, BP239, 54506 Vandoeuvre-les-Nancy, Cedex (France); Jakobsen, I. [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Chen, B.D. [Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Roos, P. [Radiation Research Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Thiry, Y.; Rufyikiri, G. [CEN-SCK, Radiation Protection Research Department, 200 Boeretang, 2400 Mol (Belgium); Delvaux, B. [Universite catholique de Louvain, Unite des Sciences du Sol Croix du Sud 2/10, 1348 Louvain-la-Neuve (Belgium); Declerck, S. [Universite catholique de Louvain, Unite de Microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve (Belgium)], E-mail: declerck@mbla.ucl.ac.be

    2008-05-15

    Contamination by uranium (U) occurs principally at U mining and processing sites. Uranium can have tremendous environmental consequences, as it is highly toxic to a broad range of organisms and can be dispersed in both terrestrial and aquatic environments. Remediation strategies of U-contaminated soils have included physical and chemical procedures, which may be beneficial, but are costly and can lead to further environmental damage. Phytoremediation has been proposed as a promising alternative, which relies on the capacity of plants and their associated microorganisms to stabilize or extract contaminants from soils. In this paper, we review the role of a group of plant symbiotic fungi, i.e. arbuscular mycorrhizal fungi, which constitute an essential link between the soil and the roots. These fungi participate in U immobilization in soils and within plant roots and they can reduce root-to-shoot translocation of U. However, there is a need to evaluate these observations in terms of their importance for phytostabilization strategies.

  19. Diet of Arbuscular Mycorrhizal Fungi: Bread and Butter?

    Science.gov (United States)

    Rich, Mélanie K; Nouri, Eva; Courty, Pierre-Emmanuel; Reinhardt, Didier

    2017-08-01

    Most plants entertain mutualistic interactions known as arbuscular mycorrhiza (AM) with soil fungi (Glomeromycota) which provide them with mineral nutrients in exchange for reduced carbon from the plant. Mycorrhizal roots represent strong carbon sinks in which hexoses are transferred from the plant host to the fungus. However, most of the carbon in AM fungi is stored in the form of lipids. The absence of the type I fatty acid synthase (FAS-I) complex from the AM fungal model species Rhizophagus irregularis suggests that lipids may also have a role in nutrition of the fungal partner. This hypothesis is supported by the concerted induction of host genes involved in lipid metabolism. We explore the possible roles of lipids in the light of recent literature on AM symbiosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Nutrient Exchange and Regulation in Arbuscular Mycorrhizal Symbiosis.

    Science.gov (United States)

    Wang, Wanxiao; Shi, Jincai; Xie, Qiujin; Jiang, Yina; Yu, Nan; Wang, Ertao

    2017-09-12

    Most land plants form symbiotic associations with arbuscular mycorrhizal (AM) fungi. These are the most common and widespread terrestrial plant symbioses, which have a global impact on plant mineral nutrition. The establishment of AM symbiosis involves recognition of the two partners and bidirectional transport of different mineral and carbon nutrients through the symbiotic interfaces within the host root cells. Intriguingly, recent discoveries have highlighted that lipids are transferred from the plant host to AM fungus as a major carbon source. In this review, we discuss the transporter-mediated transfer of carbon, nitrogen, phosphate, potassium and sulfate, and present hypotheses pertaining to the potential regulatory mechanisms of nutrient exchange in AM symbiosis. Current challenges and future perspectives on AM symbiosis research are also discussed. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Aggregate stability, root length and root thickness influenced by a mycorrhizal inoculum? - Results from a three-year eco-engineering field experiment on an alpine slope.

    Science.gov (United States)

    Bast, Alexander; Wilcke, Wolfgang; Lüscher, Peter; Graf, Frank; Gärtner, Holger

    2014-05-01

    In mountain environments many slopes are covered by coarse grained, glacial-, periglacial- or/and denudation-derived substrate. These slopes show a high geomorphic activity and are susceptible for erosional processes, shallow landslides or debris flows, which can result in a high socio-economic hazard potential. This is especially true for steep slopes, lacking a protecting vegetation cover. Regarding hazard prevention, eco-engineering gained in importance because related techniques provide a sustainable measure to protect erosion-prone hillslopes. The idea of using plants for sustainable erosion control and protection against shallow landslides, demands some essential requirements, as e.g., a stable seedbed providing appropriate water and nutrient supply. However, degraded alpine slopes are often unstable and the coarse-grained material shows a low retention capacity of water and nutrients. Extreme conditions like this hamper a fast and sustainable development of a protecting vegetation cover even if pioneer plants are used to stabilize the slopes. Thus, the question arises what needs to be done to give planted saplings within eco-engineering projects maximum support developing their above- and belowground structures to promote slope stabilization. Laboratory experiments using potted plants have shown a positive impact of mycorrhizal fungi inoculation plant development and soil structure, i.e. the formation of (stable) aggregates within several months. Soil aggregate stability is an integrating parameter, reflecting several aspects of the plant-soil system and for this also an indicator of soil development and soil stability. Because of this and based on the promising laboratory results, we intended to apply this approach in a field-experiment We established (i) mycorrhizal and (ii) non-mycorrhizal treated eco-engineered research plots on a field experimental scale, covering a total area of approx. 1000 m2 on an ENE exposed slope (coarse morainic and denudation

  3. 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. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Effects of nursery preconditioning through mycorrhizal inoculation and drought in Arbutus unedo L. plants.

    Science.gov (United States)

    Navarro García, Alejandra; Del Pilar Bañón Árias, Sebastián; Morte, Asunción; Sánchez-Blanco, María Jesús

    2011-01-01

    The influence of a water deficit treatment and mycorrhizal inoculation with Pisolithus tinctorius (Pers.) Coker and Couch on the water relations, gas exchange, and plant growth in Arbutus unedo L. plants was studied in order to evaluate the hardening process during the nursery period. The ability to withstand the adverse conditions after transplantation was also studied. Mycorrhizal and non-mycorrhizal seedlings of A. unedo were pot-grown for 4 months in a greenhouse (nursery period), during which time two irrigation treatments, well watered (100% water holding capacity, leaching 20% of the applied water) and deficit irrigation (50% of the well watered), were applied. Subsequently, the plants were transplanted to the field and well irrigated (transplanting period), after which and until the end of the experiment they received no water (establishment period). At the end of the nursery period, both water deficit and mycorrhizae were seen to have altered the plant morphology. Mycorrhizal plants had lower leaf area and improved leaf color parameters, while the water deficit increased root dry weight and the root/shoot ratio. Mycorrhizal plants had higher leaf water potential values than non-inoculated plants. Mycorrhizae increased stomatal conductance and photosynthesis values, especially in stressed plants. Drought led to an osmotic adjustment and a decrease in the leaf water potential values at turgor loss point in the mycorrhizal plants. Cell wall rigidity, measured as increased bulk modulus of elasticity, was decreased by the mycorrhizae effect. After transplanting, no differences were found in the water relations or gas exchange values between treatments. During the establishment period, the plants that had been exposed to both drought and mycorrhizae showed a better water status (higher leaf water and turgor potential values) and higher gas exchange values. In conclusion, water deficit and mycorrhizal inoculation of A. unedo plants in nursery produced changes in

  5. 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.

  6. 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

  7. DETERMINACIÓN DE LA DEPENDENCIA MICORRIZAL DEL LULO Determination Of Mycorrhizal Dependency Of Lulo

    Directory of Open Access Journals (Sweden)

    OCTAVIO GONZÁLEZ

    Full Text Available Se realizó un experimento de invernadero para determinar la dependencia micorrizal del lulo (Solanum quitoense Lam. híbrido “La selva”. Se utilizó un diseño experimental completamente al azar, los tratamientos tuvieron un arreglo factorial 3x2 con tres repeticiones; estos consistieron en la combinación de tres niveles de fósforo (P en la solución del suelo (0,002, 0,02 y 0,2 mg L-1 con dos niveles de inoculación del hongo micorrizal Glomus aggregatum (inoculado y no inoculado. Se emplearon como variables respuesta el contenido de P foliar en función del tiempo, la masa seca aérea y de raíces, la colonización micorrizal, la dependencia micorrizal y la morfología del sistema de raíces al momento de la cosecha. Los resultados indican que esta especie puede ser clasificada como moderadamente dependiente de la asociación micorrizal. La dependencia micorrizal fue mayor a 0,002 mg L-1. Todas las plantas inoculadas con G. aggregatum exhibieron colonización micorrizal, mientras que ninguna de las plantas no inoculadas desarrollaron la asociación micorrizal. La inoculación modificó significativamente la longitud y área superficial del sistema de raíces en las plantas de lulo en los niveles 0,002 y 0,02 mg L-1.A greenhouse experiment was carried out to determine the mycorrhizal dependency of lulo (Solanum quitoense Lam.. An experimental design completely randomized was used, treatments were arranged in factorial combination 3x2, which consisted of the combination of three soil solution phosphorus (P concentration (0.002, 0.02 and 0.2 mg L-1 and two levels of inoculation with the mycorrhizal fungus Glomus aggregatum (inoculated and uninoculated. Foliar P content was monitored as a function of time. At harvest, shoot and root dry weight, shoot P content, mycorrhizal colonization, mycorrhizal dependency, and root morphology were determined. The results indicated that lulo can be classified as moderately dependent on the mycorrhizal

  8. Diversity and dynamics of mycorrhizal associations in tropical rain forests with different disturbance regimes in South Cameroon

    NARCIS (Netherlands)

    Onguene, N.A.

    2000-01-01

    The present study documents the occurrence of mycorrhizal associations in the rain forests of south Cameroon. All species investigated are mycorrhizal. Most timber species form arbuscular mycorrhiza, but some timber species, which usually occur in clumps, form ectomycorrhiza. Species

  9. Plant-fungus competition for nitrogen erases mycorrhizal growth benefits of Andropogon gerardii under limited nitrogen supply

    Czech Academy of Sciences Publication Activity Database

    Püschel, David; Janoušková, Martina; Hujslová, M.; Slavíková, R.; Gryndlerová, H.; Jansa, J.

    2016-01-01

    Roč. 6, č. 13 (2016), s. 4332-4346 ISSN 2045-7758 Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal fungi * nutrient uptake response * mycorrhizal benefits and costs Subject RIV: EF - Botanics Impact factor: 2.440, year: 2016

  10. Aspen-associated mycorrhizal fungal production and respiration as a function of changing CO2, O3 and climatic variables

    Science.gov (United States)

    Carrie J. Andrew; Linda T.A. van Diepen; R. Michael Miller; Erik A. Lilleskov

    2014-01-01

    The relationships of mycorrhizal fungal respiration and productivity to climate and atmospheric chemistry remain under characterized. We quantified mycorrhizal sporocarp and hyphal respiration, as well as growing season net hyphal production, under ambient and elevated carbon dioxide (CO2) and ozone (O3) in relation to...

  11. [Effects of arbuscular mycorrhizal fungi on plant growth and osmotic adjustment matter content of trifoliate orange seedling under water stress].

    Science.gov (United States)

    Wu, Qiang-Sheng; Xia, Ren-Xue

    2004-10-01

    The effects of arbuscular mycorrhizal fungi Glomus mosseae on plant growth and osmotic adjustment matter content of trifoliate orange [Poncirus trifoliata (L.) Raf.] seedlings under water stress were studied in potted culture. The results showed that arbuscular mycorrhizal fungi inoculation could increase plant growth, such as plant height, stem diameter, leaf area, shoot dry weight, root dry weight and plant dry weight, when the water content of soil was 20%, 16% and 12%. Arbuscular mycorrhizal fungi inoculation also promoted active absorbing areas of plant root and absorption of P from plant rhizosphere, enhanced the accumulated quantities of soluble sugar content in leaves and roots, and reduced proline content of leaf. Plant inoculated with arbuscular mycorrhiza had higher plant water use efficiency than non-mycorrhizal plants. Drought tolerance of trifoliate orange seedling inoculated with arbuscular mycorrhiza was enhanced. Effects of arbuscular mycorrhizal fungi inoculation on trifoliate orange seedling under 20% and 16% water content of soil were more significant than under 12% water content of soil. Arbuscular mycorrhizal fungi infection was severely restrained by 12% water content of soil. Thus, effects of arbuscular mycorrhizal fungi on plant probably positively related to the arbuscular mycorrhizal inoculated percentage.

  12. Plant Protection Research Institute

    Directory of Open Access Journals (Sweden)

    N. Allsopp

    1993-12-01

    Full Text Available A survey of the mycorrhizal status of plants growing in the Cape Floristic Region of South Africa was undertaken to assess the range of mycorrhizal types and their dominance in species characteristic of this region. Records were obtained by ex­amining the root systems of plants growing in three Cape lowland vegetation types, viz. West Coast Strandveld, West Coast Renosterveld and Sand Plain Lowland Fynbos for mycorrhizas, as well as by collating literature records of mycorrhizas on plants growing in the region. The mycorrhizal status of 332 species is listed, of which 251 species are new records. Members of all the important families in this region have been examined. Mycorrhizal status appears to be associated mainly with taxonomic position of the species. Extrapolating from these results, we conclude that 62% of the flora of the Cape Floristic Region form vesicular-arbuscular mycorrhizas, 23% have no mycorrhizas, 8% are ericoid mycorrhizal, 2% form orchid mycorrhizas, whereas the mycorrhizal status of 4% of the flora is unknown. There were no indigenous ectomycor- rhizal species. The proportion of non-mycorrhizal species is high compared to other ecosystems. In particular, the lack of mycorrhizas in several important perennial families in the Cape Floristic Region is unusual. The diversity of nutrient acquir­ing adaptations, including the range of mycorrhizas and cluster roots in some non-mycorrhizal families, may promote co­existence of plants in this species-rich region.

  13. Environmental and genetic effects on the formation of ectomycorrhizal and arbuscular mycorrhizal associations in cottonwoods.

    Science.gov (United States)

    Gehring, Catherine A; Mueller, Rebecca C; Whitham, Thomas G

    2006-08-01

    Although both environment and genetics have been shown to affect the mycorrhizal colonization of host plants, the impacts of these factors on hosts that can be dually colonized by both ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi are less understood. We examined the influence of environment and host crosstype on the EM and AM colonization of cottonwoods (Populus angustifolia and natural hybrids) by comparing levels of colonization of trees growing in common gardens that differed in elevation and soil type. We also conducted a supplemental watering experiment to determine the influence of soil moisture on AM and EM colonization. Three patterns emerged. First, garden location had a significant impact on mycorrhizal colonization, such that EM colonization was 30% higher and AM colonization was 85% lower in the higher elevation garden than the lower elevation garden. Second, crosstype affected total (EM + AM) colonization, but did not affect EM or AM colonization. Similarly, a significant garden x crosstype interaction was found for total colonization, but not for EM or AM colonization. Third, experimental watering resulted in 33% higher EM colonization and 45% lower AM colonization, demonstrating that soil moisture was a major driver of the mycorrhizal differences observed between the gardens. We conclude that environment, particularly soil moisture, has a larger influence on colonization by AM versus EM fungi than host genetics, and suggest that environmental stress may be a major determinant of mycorrhizal colonization in dually colonized host plants.

  14. Total fatty acid composition in the characterization and identification of orchid mycorrhizal fungi Epulorhiza spp.

    Directory of Open Access Journals (Sweden)

    Marlon Corrêa Pereira

    2011-08-01

    Full Text Available Rhizoctonia-like fungi are the main mycorrhizal fungi in orchid roots. Morphological characterization and analysis of conserved sequences of genomic DNA are frequently employed in the identification and study of fungi diversity. However, phytopathogenic Rhizoctonia-like fungi have been reliably and accurately characterized and identified through the examination of the fatty acid composition. To evaluate the efficacy of fatty acid composition in characterizing and identifying Rhizoctonia-like mycorrhizal fungi in orchids, three Epulorhiza spp. mycorrhizal fungi from Epidendrum secundum, two unidentified fungi isolated from Epidendrum denticulatum, and a phytopathogenic fungus, Ceratorhiza sp. AGC, were grouped based on the profile of their fatty acids, which was assessed by the Euclidian and Mahalanobis distances and the UPGMA method. Dendrograms distinguished the phytopathogenical isolate of Ceratorhiza sp. AGC from the mycorrhizal fungi studied. The symbionts of E. secundum were grouped into two clades, one containing Epulorhiza sp.1 isolates and the other the Epulorhiza sp.2 isolate. The similarity between the symbionts of E. denticulatum and Epulorhiza spp. fungi suggests that symbionts found in E. denticulatum may be identified as Epulorhiza. These results were corroborated by the analysis of the rDNA ITS region. The dendrogram constructed based on the Mahalanobis distance differentiated the clades most clearly. Fatty acid composition analysis proved to be a useful tool for characterizing and identifying Rhizoctonia-like mycorrhizal fungi.

  15. Nutraceutical value and safety of tomato fruits produced by mycorrhizal plants.

    Science.gov (United States)

    Giovannetti, M; Avio, L; Barale, R; Ceccarelli, N; Cristofani, R; Iezzi, A; Mignolli, F; Picciarelli, P; Pinto, B; Reali, D; Sbrana, C; Scarpato, R

    2012-01-01

    Tomato fruit has assumed the status of 'functional food' due to the association between its consumption and a reduced likelihood of certain types of cancers and CVD. The nutraceutical value of tomatoes can be affected by the cultivation conditions, e.g. the phytochemical content of the fruits may increase with the establishment of beneficial mycorrhizal symbioses in the plants. A multidisciplinary study was carried out to gain knowledge on the antioxidant, oestrogenic/anti-oestrogenic and genotoxic activity of tomato fruits produced by mycorrhizal plants. The present results showed that the symbiosis positively affected the growth and mineral nutrient content of tomato plants and enhanced the nutritional and nutraceutical value of tomato fruits through modifications of plant secondary metabolism, which led to increased levels of lycopene in fruits obtained from mycorrhizal plants, compared with controls. Moreover, such changes did not result in the production of mutagenic compounds, since tomato extracts induced no in vitro genotoxic effects. Fruit extracts, both hydrophilic and the lipophilic fractions, originating from mycorrhizal plants strongly inhibited 17-β-oestradiol-human oestrogen receptor binding, showing significantly higher anti-oestrogenic power compared with controls. The present study shows that beneficial plant symbionts, such as mycorrhizal fungi, can lead to the production of safe and high-quality food, which is an important societal issue strongly demanded by both consumers and producers.

  16. Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening.

    Science.gov (United States)

    Chialva, Matteo; Zouari, Inès; Salvioli, Alessandra; Novero, Mara; Vrebalov, Julia; Giovannoni, James J; Bonfante, Paola

    2016-07-01

    Systemic responses to an arbuscular mycorrhizal fungus reveal opposite phenological patterns in two tomato ripening mutants depending whether ethylene or light reception is involved. The availability of tomato ripening mutants has revealed many aspects of the genetics behind fleshy fruit ripening, plant hormones and light signal reception. Since previous analyses revealed that arbuscular mycorrhizal symbiosis influences tomato berry ripening, we wanted to test the hypothesis that an interplay might occur between root symbiosis and fruit ripening. With this aim, we screened seven tomato mutants affected in the ripening process for their responsiveness to the arbuscular mycorrhizal fungus Funneliformis mosseae. Following their phenological responses we selected two mutants for a deeper analysis: Green ripe (Gr), deficient in fruit ethylene perception and high-pigment-1 (hp-1), displaying enhanced light signal perception throughout the plant. We investigated the putative interactions between ripening processes, mycorrhizal establishment and systemic effects using biochemical and gene expression tools. Our experiments showed that both mutants, notwithstanding a normal mycorrhizal phenotype at root level, exhibit altered arbuscule functionality. Furthermore, in contrast to wild type, mycorrhization did not lead to a higher phosphate concentration in berries of both mutants. These results suggest that the mutations considered interfere with arbuscular mycorrhiza inducing systemic changes in plant phenology and fruits metabolism. We hypothesize a cross talk mechanism between AM and ripening processes that involves genes related to ethylene and light signaling.

  17. Phosphate Uptake from Phytate Due to Hyphae-Mediated Phytase Activity by Arbuscular Mycorrhizal Maize

    Directory of Open Access Journals (Sweden)

    Gu Feng

    2017-04-01

    Full Text Available Phytate is the most abundant form of soil organic phosphorus (P. Increased P nutrition of arbuscular mycorrhizal plants derived from phytate has been repeatedly reported. Earlier studies assessed acid phosphatase rather than phytase as an indication of mycorrhizal fungi-mediated phytate use. We investigated the effect of mycorrhizal hyphae-mediated phytase activity on P uptake by maize. Two maize (Zea mays L. cultivars, non-inoculated or inoculated with the arbuscular mycorrhizal fungi Funneliformis mosseae or Claroideoglomus etunicatum, were grown for 45 days in two-compartment rhizoboxes, containing a root compartment and a hyphal compartment. The soil in the hyphal compartment was supplemented with 20, 100, and 200 mg P kg-1 soil as calcium phytate. We measured activity of phytase and acid phosphatase in the hyphal compartment, hyphal length density, P uptake, and plant biomass. Our results showed: (1 phytate addition increased phytase and acid phosphatase activity, and resulted in larger P uptake and plant biomass; (2 increases in P uptake and biomass were correlated with phytase activity but not with acid phosphatase activity; (3 lower phytate addition rate increased, but higher addition rate decreased hyphal length density. We conclude that P from phytate can be taken up by arbuscular mycorrhizal plants and that phytase plays a more important role in mineralizing phytate than acid phosphatase.

  18. Occurrence of arbuscular mycorrhizal fungi on King George Island, South Shetland Islands, Antarctica

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    MARISÂNGELA V. BARBOSA

    2017-08-01

    Full Text Available ABSTRACT Arbuscular mycorrhizal fungi make up an important ecological niche in ecosystems, and knowledge of their diversity in extreme environments is still incipient. The objective of this work was to evaluate the density and diversity of arbuscular mycorrhizal fungi in the soil of King George Island in the South Shetland Islands archipelago, Antarctica. For that, soil and roots of Deschampsia antarctica were collected at the brazilian research station in Antarctica. The spore density, species diversity and mycorrhizal colonization in the roots were evaluated. There was a low density of spores (27.4 ± 17.7 and root mycorrhizal colonization (6 ± 5.1%, which did not present statistical difference. Four species of arbuscular mycorrhizal fungi were identified, distributed in two genera: three species of the genus Glomus (Glomus sp1, Glomus sp2 and Glomus sp3 and one of the genus Acaulospora, which was identified at species level (Acaulospora mellea. Greater soil diversity was verified with pH 5.9 and phosphorus concentration of 111 mg dm-3, occurring two species of genus Glomus and A. mellea. Based on literature data, this may be the first record of this species of Acaulospora mellea in Antarctic soils, colonizing D. antarctica plants.

  19. Effects of tree species, water and nitrogen on mycorrhizal C flux

    Science.gov (United States)

    Menyailo, O.; Matvienko, A.

    2012-12-01

    Mycorrhiza plays an important role in global carbon cycle, especially, in forest soils, yet the effect of tree species on the amount and timing of C transfer through roots to myccorhiza is largely unknown. We studied the C transport to mycorrhiza under 6 most commonly dominant in boreal forests tree species using the mesh collars installed at the Siberian afforestation experiment. The CO2 flux from mycorrhizal and non-mycorrhizal mesh collars indicated the mycorrhizal C flux. Tree species strongly differed in C flux to mycorrhiza: more C was transferred by deciduous species than by conifers. The mycorrhizal CO2 flux was not linked to soil temperature but rather to trees phenology and to photosynthetic activity. All tree species transfered more carbon to mycorrhiza during the second half of summer and in September, this is because all the carbon photosynthesized earlier is used for building the tree biomass. Seasonal variation in C transfer to mycorrhiza was much larger than hourly variation (within a day). Nitrogen application (50 kg/ha) increased mycorrhizal C flux only under Scots pine, but not under larch, thus the effect of N application is tree species dependent. We found under most tree species that more C was transferred by trees to mycorrhiza in root-free collars, where the soil moisture was higher than in collars with roots. This suggests that trees preferentially support those parts of mycorrhiza, which can gain extra-resources.

  20. An integrated functional approach to dissect systemic responses in maize to arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Gerlach, Nina; Schmitz, Jessica; Polatajko, Aleksandra; Schlüter, Urte; Fahnenstich, Holger; Witt, Sandra; Fernie, Alisdair R; Uroic, Kalle; Scholz, Uwe; Sonnewald, Uwe; Bucher, Marcel

    2015-08-01

    Most terrestrial plants benefit from the symbiosis with arbuscular mycorrhizal fungi (AMF) mainly under nutrient-limited conditions. Here the crop plant Zea mays was grown with and without AMF in a bi-compartmented system separating plant and phosphate (Pi) source by a hyphae-permeable membrane. Thus, Pi was preferentially taken up via the mycorrhizal Pi uptake pathway while other nutrients were ubiquitously available. To study systemic effects of mycorrhizal Pi uptake on leaf status, leaves of these plants that display an increased biomass in the presence of AMF were subjected to simultaneous ionomic, transcriptomic and metabolomic analyses. We observed robust changes of the leaf elemental composition, that is, increase of P, S and Zn and decrease of Mn, Co and Li concentration in mycorrhizal plants. Although changes in anthocyanin and lipid metabolism point to an improved P status, a global increase in C versus N metabolism highlights the redistribution of metabolic pools including carbohydrates and amino acids. Strikingly, an induction of systemic defence gene expression and concomitant accumulation of secondary metabolites such as the terpenoids alpha- and beta-amyrin suggest priming of mycorrhizal maize leaves as a mycorrhiza-specific response. This work emphasizes the importance of AM symbiosis for the physiological status of plant leaves and could lead to strategies for optimized breeding of crop species with high growth potential. © 2015 John Wiley & Sons Ltd.

  1. [Arbuscular mycorrhizal symbiosis influences the biological effects of nano-ZnO on maize].

    Science.gov (United States)

    Wang, Wei-Zhong; Wang, Fa-Yuan; Li, Shuai; Liu, Xue-Qin

    2014-08-01

    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, 2000 and 3 000 mg x 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, and Cu uptake in shoots all decreased. Compared with the controls, arbuscular mycorrhizal inoculation improved the growth and P, N and K nutrition of maize, enhanced total root length, total surface area and total volume, and increased Zn allocation to roots when nano-ZnO was added. Our results firstly show that nano-ZnO in soil induces toxicity to arbuscular mycorrhizae, while arbuscular mycorrhizal inoculation can alleviate its toxicity and play a protective role in plants.

  2. Contrasting phosphate acquisition of mycorrhizal fungi with that of root hairs using the root hairless barley mutant

    DEFF Research Database (Denmark)

    Jakobsen, I.; Chen, B.D.; Munkvold, L.

    2005-01-01

    Comparisons between plant species or cultivars differing in root hair length have indicated a major impact of root hairs on the mycorrhizal dependency of plants with respect to phosphate (P) uptake. The current study aimed to investigate this relationship by comparing directly the mycorrhizal dep...... effectively in promoting plant growth than P provided by root hairs.......Comparisons between plant species or cultivars differing in root hair length have indicated a major impact of root hairs on the mycorrhizal dependency of plants with respect to phosphate (P) uptake. The current study aimed to investigate this relationship by comparing directly the mycorrhizal...... plants at low P levels was substantially lower than that of the non-mycorrhizal wild-type plants. However, P uptake of the mutant was much increased by mycorrhizas and with one fungus, the additional P uptake was effectively translated into increased plant growth. Roots of the mutant contained typical...

  3. Succession of arbuscular mycorrhizal fungi along a 52-year agricultural recultivation chronosequence.

    Science.gov (United States)

    Roy, Julien; Reichel, Rüdiger; Brüggemann, Nicolas; Hempel, Stefan; Rillig, Matthias C

    2017-09-01

    Arbuscular mycorrhizal (AM) fungi provide a range of functions in natural and managed ecosystems. However, the trajectory of AM fungal diversity after land degradation is poorly known. We studied the succession of AM fungi along an agricultural recultivation chronosequence after open-cast mining near Cologne, Germany. We used high-throughput sequencing of the large-subunit ribosomal RNA genes to characterize the soil AM fungal communities of 10 agricultural fields spanning 52 years of recultivation. During three years, soils are recultivated with a legume, and then converted to agriculture to be later returned to local farmers implementing conventional agriculture. Our data reveal a quick and strong recovery of AM fungal richness after a few years of recultivation, but also a rapid decline following years of conventional agriculture. The community structure was strongly correlated to mineral nitrogen and phosphorus, richness peaking at high N:P ratio. This work represents the first molecular data documenting temporal patterns of AM fungal communities in agriculture; it shows the deleterious effect of conventional agricultural practices on AM fungal communities developing over time. Nonetheless, the highly dynamic nature of AM fungal communities suggests strategies for site-level management for which considering N:P stoichiometry is crucial. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Physiological Responses and Gene Co-Expression Network of Mycorrhizal Roots under K+ Deprivation.

    Science.gov (United States)

    Garcia, Kevin; Chasman, Deborah; Roy, Sushmita; Ané, Jean-Michel

    2017-03-01

    Arbuscular mycorrhizal (AM) associations enhance the phosphorous and nitrogen nutrition of host plants, but little is known about their role in potassium (K+) nutrition. Medicago truncatula plants were cocultured with the AM fungus Rhizophagus irregularis under high and low K+ regimes for 6 weeks. We determined how K+ deprivation affects plant development and mineral acquisition and how these negative effects are tempered by the AM colonization. The transcriptional response of AM roots under K+ deficiency was analyzed by whole-genome RNA sequencing. K+ deprivation decreased root biomass and external K+ uptake and modulated oxidative stress gene expression in M. truncatula roots. AM colonization induced specific transcriptional responses to K+ deprivation that seem to temper these negative effects. A gene network analysis revealed putative key regulators of these responses. This study confirmed that AM associations provide some tolerance to K+ deprivation to host plants, revealed that AM symbiosis modulates the expression of specific root genes to cope with this nutrient stress, and identified putative regulators participating in these tolerance mechanisms. © 2017 American Society of Plant Biologists. All Rights Reserved.

  5. TRANSITION METAL TRANSPORT IN PLANTS AND ASSOCIATED ENDOSYMBIONTS: ARBUSCULAR MYCORRHIZAL FUNGI AND RHIZOBIA

    Directory of Open Access Journals (Sweden)

    Manuel González-Guerrero

    2016-07-01

    Full Text Available Transition metals such as iron, copper, zinc, or molybdenum, are essential nutrients for plants. These elements are involved in almost every biological process, including photosynthesis, tolerance to biotic and abiotic stress, or symbiotic nitrogen fixation. However, plants often grow in soils with limiting metallic oligonutrient bioavailability. Consequently, to ensure the proper metal levels, plants have developed a complex metal uptake and distribution system, that not only involves the plant itself, but also its associated microorganisms. These microorganisms can simply increase metal solubility in soils and making them more accessible to the host plant, as well as induce the plant metal deficiency response, or deliver directly transition elements to cortical cells. Other, instead of providing metals can act as metal sinks, such as endosymbiotic rhizobia in legume nodules that requires relatively large amounts to carry out nitrogen fixation. In this review, we propose to do an overview of metal transport mechanisms in the plant-microbe system, emphasizing the role of arbuscular mycorrhizal fungi and endosymbiotic rhizobia.

  6. Arbuscular Mycorrhizal Symbiosis Requires a Phosphate Transceptor in the Gigaspora margarita Fungal Symbiont.

    Science.gov (United States)

    Xie, Xianan; Lin, Hui; Peng, Xiaowei; Xu, Congrui; Sun, Zhongfeng; Jiang, Kexin; Huang, Antian; Wu, Xiaohui; Tang, Nianwu; Salvioli, Alessandra; Bonfante, Paola; Zhao, Bin

    2016-12-05

    The majority of terrestrial vascular plants are capable of forming mutualistic associations with obligate biotrophic arbuscular mycorrhizal (AM) fungi from the phylum Glomeromycota. This mutualistic symbiosis provides carbohydrates to the fungus, and reciprocally improves plant phosphate uptake. AM fungal transporters can acquire phosphate from the soil through the hyphal networks. Nevertheless, the precise functions of AM fungal phosphate transporters, and whether they act as sensors or as nutrient transporters, in fungal signal transduction remain unclear. Here, we report a high-affinity phosphate transporter GigmPT from Gigaspora margarita that is required for AM symbiosis. Host-induced gene silencing of GigmPT hampers the development of G. margarita during AM symbiosis. Most importantly, GigmPT functions as a phosphate transceptor in G. margarita regarding the activation of the phosphate signaling pathway as well as the protein kinase A signaling cascade. Using the substituted-cysteine accessibility method, we identified residues A 146 (in transmembrane domain [TMD] IV) and Val 357 (in TMD VIII) of GigmPT, both of which are critical for phosphate signaling and transport in yeast during growth induction. Collectively, our results provide significant insights into the molecular functions of a phosphate transceptor from the AM fungus G. margarita. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  7. Diversity of Rhizosphere Soil Arbuscular Mycorrhizal Fungi in Various Soybean Cultivars under Different Continuous Cropping Regimes

    Science.gov (United States)

    Jie, Weiguang; Liu, Xiaorui; Cai, Baiyan

    2013-01-01

    Recent studies have shown that continuous cropping in soybean causes substantial changes to the microbial community in rhizosphere soil. In this study, we investigated the effects of continuous cropping for various time periods on the diversity of rhizosphere soil arbuscular mycorrhizal (AM) fungi in various soybean cultivars at the branching stage. The soybean cultivars Heinong 37 (an intermediate cultivar), Heinong 44 (a high-fat cultivar) and Heinong 48 (a high-protein cultivar) were seeded in a field and continuously cropped for two or three years. We analyzed the diversity of rhizosphere soil AM fungi of these soybean plants at the branching stage using morphological and denaturing gradient gel electrophoresis (DGGE) techniques. The clustering analysis of unweighted pair-group method with arithmetic averages (UPGMA) was then used to investigate the AM fungal community shifts. The results showed that increasing the number of years of continuous cropping can improve the colonization rate of AM fungi in different soybean cultivars at the branching stage. The dominant AM fungi in the experimental fields were Funneliformismosseae and Glomus spp. The number of years of continuous cropping and the soybean cultivar both had obvious effects on the diversity of AM fungi, which was consistent with the results of colonization rate analysis. This study establishes a basis for screening dominant AM fungi of soybean. In addition, the results of this study may be useful for the development of AM fungal inoculants. PMID:23977368

  8. SEEDLINGS ESTABLISHMENT OF Eucalyptus grandis MYCORRHIZATED WITH Pisolithus microcarpus (UFSC Pt 116 IN SANDY SOIL

    Directory of Open Access Journals (Sweden)

    Andréa Hentz de Mello

    2009-09-01

    Full Text Available The aim of this work was to evaluate the survival and the initial growth of mycorrhizated eucalypts with Pisolithus microcarpus (UFSC Pt 116 ectomycorrhizal fungus, after its transplant to area subject to the arenization process in São Francisco de Assis, RS. The area was divided into four blocks, each one with four treatments (fertile turf with and without mycorrhizae, Quartzarenic Neosoil with and without mycorrhizae. Each parcel was composed of 16 seedlings arranged in four lines in the spacing of 1,5 m x 1,5 m, totalizing in each block 64 seedlings. 90 days after the planting in the field, the eucaliptus seedlings produced in turf with fungus in the fertile substratum presented a survival rate of 100 %, whereas for those produced in fertile turf without fingi, the survival rate was 92 %. The seedlings produced in the Quartzarenic Neosoil with and without mycorrhizae had a survival rate varying around 98 and 89 %, respectively. The produced seedlings with turf and fungus showed significant differences in height and stem diameter. This study showed that the Eucalyptus grandis seedlings produced in substratum fertile turf and inoculated with the Pisolithus microcarpus (UFSC Pt 116 isolated may maintain good development and establishment in the field.

  9. Insights on the Impact of Arbuscular Mycorrhizal Symbiosis on Tomato Tolerance to Water Stress1[OPEN

    Science.gov (United States)

    Siciliano, Ilenia

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development in the future of a more sustainable next-generation agriculture. The best understood function in symbiosis is an improvement in plant mineral nutrient acquisition, as exchange for carbon compounds derived from the photosynthetic process: this can enhance host growth and tolerance to environmental stresses, such as water stress (WS). However, physiological and molecular mechanisms occurring in arbuscular mycorrhiza-colonized plants and directly involved in the mitigation of WS effects need to be further investigated. The main goal of this work is to verify the potential impact of AM symbiosis on the plant response to WS. To this aim, the effect of two AM fungi (Funneliformis mosseae and Rhizophagus intraradices) on tomato (Solanum lycopersicum) under the WS condition was studied. A combined approach, involving ecophysiological, morphometric, biochemical, and molecular analyses, has been used to highlight the mechanisms involved in plant response to WS during AM symbiosis. Gene expression analyses focused on a set of target genes putatively involved in the plant response to drought, and in parallel, we considered the expression changes induced by the imposed stress on a group of fungal genes playing a key role in the water-transport process. Taken together, the results show that AM symbiosis positively affects the tolerance to WS in tomato, with a different plant response depending on the AM fungi species involved. PMID:27208301

  10. Host Plant Physiology and Mycorrhizal Functioning Shift across a Glacial through Future [CO2] Gradient1[OPEN

    Science.gov (United States)

    Mullinix, George W.R.; Ward, Joy K.

    2016-01-01

    Rising atmospheric carbon dioxide concentration ([CO2]) may modulate the functioning of mycorrhizal associations by altering the relative degree of nutrient and carbohydrate limitations in plants. To test this, we grew Taraxacum ceratophorum and Taraxacum officinale (native and exotic dandelions) with and without mycorrhizal fungi across a broad [CO2] gradient (180–1,000 µL L−1). Differential plant growth rates and vegetative plasticity were hypothesized to drive species-specific responses to [CO2] and arbuscular mycorrhizal fungi. To evaluate [CO2] effects on mycorrhizal functioning, we calculated response ratios based on the relative biomass of mycorrhizal (MBio) and nonmycorrhizal (NMBio) plants (RBio = [MBio − NMBio]/NMBio). We then assessed linkages between RBio and host physiology, fungal growth, and biomass allocation using structural equation modeling. For T. officinale, RBio increased with rising [CO2], shifting from negative to positive values at 700 µL L−1. [CO2] and mycorrhizal effects on photosynthesis and leaf growth rates drove shifts in RBio in this species. For T. ceratophorum, RBio increased from 180 to 390 µL L−1 and further increases in [CO2] caused RBio to shift from positive to negative values. [CO2] and fungal effects on plant growth and carbon sink strength were correlated with shifts in RBio in this species. Overall, we show that rising [CO2] significantly altered the functioning of mycorrhizal associations. These symbioses became more beneficial with rising [CO2], but nonlinear effects may limit plant responses to mycorrhizal fungi under future [CO2]. The magnitude and mechanisms driving mycorrhizal-CO2 responses reflected species-specific differences in growth rate and vegetative plasticity, indicating that these traits may provide a framework for predicting mycorrhizal responses to global change. PMID:27573369

  11. Dispersal of arbuscular mycorrhizal fungi and plants during succession

    Science.gov (United States)

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

    2016-11-01

    Arbuscular mycorrhizal (AM) fungi are important root symbionts that enhance plant nutrient uptake and tolerance to pathogens and drought. While the role of plant dispersal in shaping successional vegetation is well studied, there is very little information about the dispersal abilities of AM fungi. We conducted a trap-box experiment in a recently abandoned quarry at 10 different distances from the quarry edge (i.e. the potential propagule source) over eleven months to assess the short term, within-year, arrival of plant and AM fungal assemblages and hence their dispersal abilities. Using DNA based techniques we identified AM fungal taxa and analyzed their phylogenetic diversity. Plant diversity was determined by transporting trap soil to a greenhouse and identifying emerging seedlings. We recorded 30 AM fungal taxa. These contained a high proportion of ruderal AM fungi (30% of taxa, 79% of sequences) but the richness and abundance of AM fungi were not related to the distance from the presumed propagule source. The number of sequences of AM fungi decreased over time. Twenty seven plant species (30% of them ruderal) were recorded from the soil seed traps. Plant diversity decreased with distance from the propagule source and increased over time. Our data show that AM fungi with ruderal traits can be fast colonizers of early successional habitats.

  12. Elemental composition of arbuscular mycorrhizal fungi at high salinity.

    Science.gov (United States)

    Hammer, Edith C; Nasr, Hafedh; Pallon, Jan; Olsson, Pål Axel; Wallander, Håkan

    2011-02-01

    We investigated the elemental composition of spores and hyphae of arbuscular mycorrhizal fungi (AMF) collected from two saline sites at the desert border in Tunisia, and of Glomus intraradices grown in vitro with or without addition of NaCl to the medium, by proton-induced X-ray emission. We compared the elemental composition of the field AMF to those of the soil and the associated plants. The spores and hyphae from the saline soils showed strongly elevated levels of Ca, Cl, Mg, Fe, Si, and K compared to their growth environment. In contrast, the spores of both the field-derived AMF and the in vitro grown G. intraradices contained lower or not elevated Na levels compared to their growth environment. This resulted in higher K:Na and Ca:Na ratios in spores than in soil, but lower than in the associated plants for the field AMF. The K:Na and Ca:Na ratios of G. intraradices grown in monoxenic cultures were also in the same range as those of the field AMF and did not change even when those ratios in the growth medium were lowered several orders of magnitude by adding NaCl. These results indicate that AMF can selectively take up elements such as K and Ca, which act as osmotic equivalents while they avoid uptake of toxic Na. This could make them important in the alleviation of salinity stress in their plant hosts.

  13. NIN Is Involved in the Regulation of Arbuscular Mycorrhizal Symbiosis

    Science.gov (United States)

    Guillotin, Bruno; Couzigou, Jean-Malo; Combier, Jean-Philippe

    2016-01-01

    Arbuscular mycorrhizal (AM) symbiosis is an intimate and ancient symbiosis found between most of terrestrial plants and fungi from the Glomeromycota family. Later during evolution, the establishment of the nodulation between legume plants and soil bacteria known as rhizobia, involved several genes of the signaling pathway previously implicated for AM symbiosis. For the past years, the identification of the genes belonging to this Common Symbiotic Signaling Pathway have been mostly done on nodulation. Among the different genes already well identified as required for nodulation, we focused our attention on the involvement of Nodule Inception (NIN) in AM symbiosis. We show here that NIN expression is induced during AM symbiosis, and that the Medicago truncatula nin mutant is less colonized than the wild-type M. truncatula strain. Moreover, nin mutant displays a defect in the ability to be infected by the fungus Rhizophagus irregularis. This work brings a new evidence of the common genes involved in overlapping signaling pathways of both nodulation and in AM symbiosis. PMID:27899928

  14. NIN is involved in the regulation of Arbuscular Mycorrhizal symbiosis.

    Directory of Open Access Journals (Sweden)

    Bruno GUILLOTIN

    2016-11-01

    Full Text Available Arbuscular mycorrhizal (AM symbiosis is an intimate and ancient symbiosis found between most of terrestrial plants and fungi from the Glomeromycota family. Later during evolution, the establishment of the nodulation between legume plants and soil bacteria known as rhizobia, involved several genes of the signalling pathway previously implicated for AM symbiosis. For the past years, the identification of the genes belonging to this Common Symbiotic Signalling Pathway have been mostly done on nodulation. Among the different genes already well identified as required for nodulation, we focused our attention on the involvement of Nodule Inception (NIN in AM symbiosis. We show here that NIN expression is induced during AM symbiosis, and that the Medicago truncatula nin mutant is less colonized than the wild type M. truncatula strain. Moreover, nin mutant displays a defect in the ability to be infected by the fungus Rhizophagus irregularis. This work brings a new evidence of the common genes involved in overlapping signalling pathways of both nodulation and in AM symbiosis.

  15. Arbuscular mycorrhizal fungi: effects on plant terpenoid accumulation.

    Science.gov (United States)

    Welling, M T; Liu, L; Rose, T J; Waters, D L E; Benkendorff, K

    2016-07-01

    Arbuscular mycorrhizal fungi (AMF) are a diverse group of soil-dwelling fungi that form symbiotic associations with land plants. AMF-plant associations promote the accumulation of plant terpenoids beneficial to human health, although how AMF mediate terpenoid accumulation is not fully understood. A critical assessment and discussion of the literature relating to mechanisms by which AMF influence plant terpenoid accumulation, and whether this symbiosis can be harnessed in horticultural ecosystems was performed. Modification of plant morphology, phosphorus availability and gene transcription involved with terpenoid biosynthetic pathways were identified as key mechanisms associated with terpenoid accumulation in AMF-colonised plants. In order to exploit AMF-plant symbioses in horticultural ecosystems it is important to consider the specificity of the AMF-plant association, the predominant factor affecting terpenoid accumulation, as well as the end use application of the harvested plant material. Future research should focus on resolving the relationship between ecologically matched AMF genotypes and terpenoid accumulation in plants to establish if these associations are effective in promoting mechanisms favourable for plant terpenoid accumulation. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Compatibility and incompatibility in hyphal anastomosis of arbuscular mycorrhizal fungi

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    Candido Barreto de Novais

    Full Text Available ABSTRACT: Arbuscular mycorrhizal fungi (AMF, which live in symbiosis with 80 % of plants, are not able to grow when separated from their hosts. Spore germination is not host-regulated and germling growth is shortly arrested in the absence of host roots. Germling survival chances may be increased by hyphal fusions (anastomoses, which allow access to nutrients flowing in the extraradical mycelium (ERM. Perfect anastomoses, occurring with high frequency among germlings and the ERM of the same isolate, show protoplasm continuity and disappearance of hyphal walls. A low frequency of perfect fusions has been detected among co-specific genetically different isolates, although fungal nuclei have been consistently detected in all perfect fusions, suggesting active nuclear migration. When plants of different taxa establish symbioses with the same AMF species, anastomoses between ERM spreading from single root systems establish a common mycelium, which is an essential element to plant nutrition and communication. The interaction among mycelia produced by different isolates may also lead to pre-fusion incompatibility which hinders anastomosis formation, or to incompatibility after fusion, which separates the hyphal compartments. Results reported here, obtained by analyses of hyphal compatibility/incompatibility in AMF, suggest that anastomosis formation and establishment of protoplasm flow, fundamental to the maintenance of mycelial physiological and genetic continuity, may affect the fitness of these ecologically important biotrophic fungi.

  17. NIN Is Involved in the Regulation of Arbuscular Mycorrhizal Symbiosis.

    Science.gov (United States)

    Guillotin, Bruno; Couzigou, Jean-Malo; Combier, Jean-Philippe

    2016-01-01

    Arbuscular mycorrhizal (AM) symbiosis is an intimate and ancient symbiosis found between most of terrestrial plants and fungi from the Glomeromycota family. Later during evolution, the establishment of the nodulation between legume plants and soil bacteria known as rhizobia, involved several genes of the signaling pathway previously implicated for AM symbiosis. For the past years, the identification of the genes belonging to this Common Symbiotic Signaling Pathway have been mostly done on nodulation. Among the different genes already well identified as required for nodulation, we focused our attention on the involvement of Nodule Inception (NIN) in AM symbiosis. We show here that NIN expression is induced during AM symbiosis, and that the Medicago truncatula nin mutant is less colonized than the wild-type M. truncatula strain. Moreover, nin mutant displays a defect in the ability to be infected by the fungus Rhizophagus irregularis. This work brings a new evidence of the common genes involved in overlapping signaling pathways of both nodulation and in AM symbiosis.

  18. Mycorrhizal colonisation of highbush blueberry and its native relatives in central Finland

    Directory of Open Access Journals (Sweden)

    A. KASURINEN

    2008-12-01

    Full Text Available Transmission electromicroscopy, trypan blue staining in combination with stereomicroscope analysis and biochemical ergosterol assay were used to study the mycorrhizal symbionts in wild bilberry (Vaccinium myrtillus, bog whortleberry (Vaccinium uliginosum and highbush blueberry (Vaccinium corymbosum roots. TEM-analysis showed that in all species ericoid mycorrhizas formed hyphae coil inside the epidermal root cells. In stereomicroscopic viewing the highest mycorrhizal colonisation was observed in the roots of wild bilberries (51%, whereas according to the ergosterol assay the highest total fungal biomass of roots was found in bog whortleberries (209 mg g-1 of root d. wt. Both ergosterol and microscopical method showed that the mycorrhizal associations in blueberry cultivars and their wild relatives growing on natural soil medium are frequent, although ericoid mycorrhiza formation of highbush blueberries was somewhat weaker than that of wild bilberries and bog whortleberries.

  19. Effect of arbuscular mycorrhizal fungi and pesticides on Cynara cardunculus growth

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    M. MARIN

    2008-12-01

    Full Text Available Wild cardoon (Cynara cardunculus L. is a promising crop for biomass production. A nursery trial was conducted to investigate the effectiveness of mycorrhizal inoculation on the biomass yield of wild cardoon seedlings and the effect of the pesticides fosetyl-Al, folpet and propamocarb, as fungicides, and isofenphos, phoxim and oxamyl, as insecticides, on cardoon plant growth and the mycorrhization. The arbuscular mycorrhizal (AM fungi inocula were: commercial inoculum with Glomus mosseae spores, and an inoculum of a Glomus sp. strain (AMF-i isolated locally. Mycorrhizal inoculation with either inoculum increased cardoon shoot biomass compared to non-inoculated control plants. The pesticide applications had a neutral or positive effect on cardoon seedling growth. However, the AM fungi colonisation did not decrease except for plants colonised by G. mosseae and treated with the insecticides isofenphos and oxamyl. Thus, the mycorrhiza can survive to pesticide concentrations employed in commercial nursery, and enhance cardoon plant productivity.

  20. Effect of Mycorrhizal Inoculation and Grain Priming on Some Quantity and Quality Properties of Lentil (Lens culinaris L.

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    mohsen azarnia

    2017-02-01

    Full Text Available Introduction: The most important problems of farmers in arid and semi-arid regions are adequate nutrition, optimum rooting, emergence, establishment and optimal density, and ultimately plant yield. Using grain priming and mycorrhizal inoculation is effective strategies in these conditions. Priming can cause earlier growth of seedling, to increase emergence rate, emergence percentage, plant tolerance to drought and salinity stress, early flowering as well as to increase the quality and quantity of yield and nutrient absorption. Plant hormones such as salicylic acid and gibberellic acid can be used for priming. Regarding plant response to environmental stresses, salicylic acid, which is an important signal molecule, plays a key role in the regulation of several physiological processes such as growth and plant development, absorption of ions, emergence and photosynthesis. Gibberellic acid (GA3 has been shown to be involved in many physiological processes such as cell division activity of meristem regions, increase the cell length, emergence speed, and emergence percentage, seedling growth in field condition, early flowering and yield. Mycorrhizal inoculation increases the availability of nutrients especially plant phosphorus, concentrations of plant hormones (auxins, cytokinins and gibberellins, chlorophyll content, the efficiency of biological nitrogen fixation, assimilates allocation to host plant organs, the changes of root structure, and improve soil structure. Materials and Methods: In order to evaluate the response of lentil to grain priming (without grain priming, hydro-priming, 100 ppm gibberellic acid, 100 ppm salicylic acid, 100 ppm gibberellic acid + 100 ppm salicylic acid and soil mycorrhizal inoculation (non-inoculated control, inoculated with Glomus moseae and Glomus intraradices, a factorial experiment based on a completely randomized block design with four replications carried out in a greenhouse and research farm of the Gonbad

  1. Variation in mycorrhizal associations with tulasnelloid fungi among populations of five Dactylorhiza species.

    Science.gov (United States)

    Jacquemyn, Hans; Deja, Agnieszka; De hert, Koen; Cachapa Bailarote, Bruno; Lievens, Bart

    2012-01-01

    Orchid species rely on mycorrhizal symbioses with fungi to complete their life cycle. Although there is mounting evidence that orchids can associate with several fungi from different clades or families, less is known about the actual geographic distribution of these fungi and how they are distributed across different orchid species within a genus. We investigated among-population variation in mycorrhizal associations in five species of the genus Dactylorhiza (D. fuchsii, D. incarnata, D. maculata, D. majalis and D. praetermissa) using culture-independent detection and identification techniques enabling simultaneous detection of multiple fungi in a single individual. Mycorrhizal specificity, determined as the number of fungal operational taxonomic units (OTUs), and phylogenetic diversity of fungi were compared between species, whereas discriminant analysis was used to compare mycorrhizal spectra across populations and species. Based on a 95% cut-off value in internal transcribed spacer (ITS) sequence similarity, a total of ten OTUs was identified belonging to three different clades within the Tulasnellaceae. Most OTUs were found in two or more Dactylorhiza species, and some of them were common and widespread, occurring in more than 50% of all sampled populations. Each orchid species associated with at least five different OTUs, whereas most individuals also associated with two or more fungal OTUs at the same time. Phylogenetic diversity, corrected for species richness, was not significantly different between species, confirming the generality of the observed orchid mycorrhizal associations. We found that the investigated species of the genus Dactylorhiza associated with a wide range of fungal OTUs from the Tulasnellaceae, some of which were widespread and common. These findings challenge the idea that orchid rarity is related to mycorrhizal specificity and fungal distribution.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Songlin [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamycká 129, Prague 6−Suchdol 165 21 (Czech Republic); Zhang, Xin [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Sun, Yuqing; Wu, Zhaoxiang [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Li, Tao [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Hu, Yajun [State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085 (China); Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125 (China); Lv, Jitao; Li, Gang; Zhang, Zhensong [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Zhang, Jing; Zheng, Lirong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhen, Xiangjun [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China); and others

    2016-10-05

    Highlights: • Cr immobilization in AM symbioses revealed by SEM-EDS, STXM and XAFS. • EPS like particles formed on fungal surface upon Cr(VI) stress. • Cr(VI) was reduced to mainly Cr(III)-phosphate analogues on fungal surface. • Cr can be retained by the intraradical fungal structures in mycorrhizal roots. - Abstract: 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.

  3. The plasma membrane proteome of Medicago truncatula roots as modified by arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Aloui, Achref; Recorbet, Ghislaine; Lemaître-Guillier, Christelle; Mounier, Arnaud; Balliau, Thierry; Zivy, Michel; Wipf, Daniel; Dumas-Gaudot, Eliane

    2017-07-19

    In arbuscular mycorrhizal (AM) roots, the plasma membrane (PM) of the host plant is involved in all developmental stages of the symbiotic interaction, from initial recognition to intracellular accommodation of intra-radical hyphae and arbuscules. Although the role of the PM as the agent for cellular morphogenesis and nutrient exchange is especially accentuated in endosymbiosis, very little is known regarding the PM protein composition of mycorrhizal roots. To obtain a global overview at the proteome level of the host PM proteins as modified by symbiosis, we performed a comparative protein profiling of PM fractions from Medicago truncatula roots either inoculated or not with the AM fungus Rhizophagus irregularis. PM proteins were isolated from root microsomes using an optimized discontinuous sucrose gradient; their subsequent analysis by liquid chromatography followed by mass spectrometry (MS) identified 674 proteins. Cross-species sequence homology searches combined with MS-based quantification clearly confirmed enrichment in PM-associated proteins and depletion of major microsomal contaminants. Changes in protein amounts between the PM proteomes of mycorrhizal and non-mycorrhizal roots were monitored further by spectral counting. This workflow identified a set of 82 mycorrhiza-responsive proteins that provided insights into the plant PM response to mycorrhizal symbiosis. Among them, the association of one third of the mycorrhiza-responsive proteins with detergent-resistant membranes pointed at partitioning to PM microdomains. The PM-associated proteins responsive to mycorrhization also supported host plant control of sugar uptake to limit fungal colonization, and lipid turnover events in the PM fraction of symbiotic roots. Because of the depletion upon symbiosis of proteins mediating the replacement of phospholipids by phosphorus-free lipids in the plasmalemma, we propose a role of phosphate nutrition in the PM composition of mycorrhizal roots.

  4. Conditions Promoting Mycorrhizal Parasitism are of Minor Importance for Competitive Interactions in Two Differentially Mycotrophic Species

    Directory of Open Access Journals (Sweden)

    Martina Friede

    2016-09-01

    Full Text Available Interactions of plants with arbuscular mycorrhizal fungi (AMF may range along a broad continuum from strong mutualism to parasitism, with mycorrhizal benefits received by the plant being determined by climatic and edaphic conditions affecting the balance between carbon costs vs. nutritional benefits. Thus, environmental conditions promoting either parasitism or mutualism can influence the mycorrhizal growth dependency (MGD of a plant and in consequence may play an important role in plant-plant interactions.In a multifactorial field experiment we aimed at disentangling the effects of environmental and edaphic conditions, namely the availability of light, phosphorus and nitrogen, and the implications for competitive interactions between Hieracium pilosella and Corynephorus canescens for the outcome of the AMF symbiosis. Both species were planted in single, intraspecific and interspecific combinations using a target-neighbor approach with six treatments distributed along a gradient simulating conditions for the interaction between plants and AMF ranking from mutualistic to parasitic.Across all treatments we found mycorrhizal association of H. pilosella being consistently mutualistic, while pronounced parasitism was observed in C. canescens, indicating that environmental and edaphic conditions did not markedly affect the cost:benefit ratio of the mycorrhizal symbiosis in both species. Competitive interactions between both species were strongly affected by AMF, with the impact of AMF on competition being modulated by colonization. Biomass in both species was lowest when grown in interspecific competition, with colonization being increased in the less mycotrophic C. canescens, while decreased in the obligate mycotrophic H. pilosella. Although parasitism-promoting conditions negatively affected MGD in C. canescens, these effects were small as compared to growth decreases related to increased colonization levels in this species. Thus, the lack of plant

  5. Conditions Promoting Mycorrhizal Parasitism Are of Minor Importance for Competitive Interactions in Two Differentially Mycotrophic Species

    Science.gov (United States)

    Friede, Martina; Unger, Stephan; Hellmann, Christine; Beyschlag, Wolfram

    2016-01-01

    Interactions of plants with arbuscular mycorrhizal fungi (AMF) may range along a broad continuum from strong mutualism to parasitism, with mycorrhizal benefits received by the plant being determined by climatic and edaphic conditions affecting the balance between carbon costs vs. nutritional benefits. Thus, environmental conditions promoting either parasitism or mutualism can influence the mycorrhizal growth dependency (MGD) of a plant and in consequence may play an important role in plant-plant interactions. In a multifactorial field experiment we aimed at disentangling the effects of environmental and edaphic conditions, namely the availability of light, phosphorus and nitrogen, and the implications for competitive interactions between Hieracium pilosella and Corynephorus canescens for the outcome of the AMF symbiosis. Both species were planted in single, intraspecific and interspecific combinations using a target-neighbor approach with six treatments distributed along a gradient simulating conditions for the interaction between plants and AMF ranking from mutualistic to parasitic. Across all treatments we found mycorrhizal association of H. pilosella being consistently mutualistic, while pronounced parasitism was observed in C. canescens, indicating that environmental and edaphic conditions did not markedly affect the cost:benefit ratio of the mycorrhizal symbiosis in both species. Competitive interactions between both species were strongly affected by AMF, with the impact of AMF on competition being modulated by colonization. Biomass in both species was lowest when grown in interspecific competition, with colonization being increased in the less mycotrophic C. canescens, while decreased in the obligate mycotrophic H. pilosella. Although parasitism-promoting conditions negatively affected MGD in C. canescens, these effects were small as compared to growth decreases related to increased colonization levels in this species. Thus, the lack of plant control over

  6. Mycorrhizal association in gametophytes and sporophytes of the fern Pteris vittata (Pteridaceae with Glomus intraradices

    Directory of Open Access Journals (Sweden)

    Alicia E Martinez

    2012-06-01

    Full Text Available Ferns, which are usually colonizing different environments and their roots frequently present mycorrhization, have two adult stages in their life cycle, the sporophytic and the gametophytic phase. This paper describes the experimental mycorrhizal association between Pteris vittata leptosporangiate fern and a strain of Glomus intraradices during the life cycle of the fern, from spore germination to the development of a mature sporophyte. The aim of this study was to compare the colonization pattern of in vitro cultures of G. intraradices along the fern life cycle with those found in nature. For this, mature spores were obtained from fertile P. vittata fronds growing in walls of Buenos Aires city, Argentina. Roots were stained and observed under the light microscope for arbuscular mycorrhizal colonization. Approximately, 75 fern spores were cultured in each pot filled with a sterile substrate and G. intraradices (BAFC N° 51.331 as inoculum on the surface. After germination took place, samples were taken every 15 days until the fern cycle was completed. In order to determine colonization dynamics each sample was observed under optical and confocal microscope after staining. Gametophyte was classified as Adiantum type. Male and female gametangia were limited to the lower face, mycorrhizal colonization started when they were differentiated and took place through the rhizoids. Spores and vesicles were not found in this cycle stage. Paris-type mycorrhizal colonization was established in the midrib and in the embrionary foot. It was colonized by external mycelium. When the first root was developed soil inoculum colonized de novo this structure and Arum-type colonization was observed. This study proves that the type of colonization is determined by the structure of the host, not by the fungus. Both the gametophyte and embryo foot have determined growth and Paris-type colonization, while, sporophyte roots have undetermined growth and Arum

  7. Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants

    DEFF Research Database (Denmark)

    Merrild, Marie Porret; Ambus, Per; Rosendahl, Søren

    2013-01-01

    Common mycorrhizal networks (CMNs) influence competition between plants, but reports regarding their precise effect are conflicting. We studied CMN effects on phosphorus (P) uptake and growth of seedlings as influenced by various disruptions of network components. Tomato (Solanum lycopersicon...... or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre‐established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed...

  8. Effect of phosphate and the arbuscular mycorrhizal fungus Glomus intraradices on disease severity of root rot of peas ( Pisum sativum ) caused by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Bødker, Lars; Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    The effects of inorganic phosphate levels and the presence of arbuscular mycorrhiza on disease severity of Aphanomyces euteiches in pea roots were studied. Disease severity on roots and epicotyl as well as the oospore number within infected root tissue were correlated with the phosphorus (P) level...... in the growth medium. The arbuscular mycorrhizal fungus Glomus intraradices increased P uptake and the P concentration in the plant but reduced disease development in peas. Polyacrylamide gel electrophoresis followed by densitometry of glucose-6-phosphate dehydrogenase specific to A.euteiches was used...

  9. The Effect of Mycorrhizal Fungi and Humic Acid on Yield and Yield Components of Sunflower

    Directory of Open Access Journals (Sweden)

    Hamideh Veysi

    2017-03-01

    was performed using LSD method (at 5% level. The figures were prepared by Microsoft Excel. Results and discussion Mean comparisons showed that highest seed number per head belonged to plants under G. mosseae, without chemical fertilizer applying and without the use of humic acid (Fig. 5. The highest thousand seed weight obtained from using 8 and 16 kg.ha-1 humic acid without chemical fertilizer and applying 0 and 8 kg.ha-1 humic acid and using 50 and 100% chemical fertilizer. It seems that humic acid has antagonistic effects with chemical fertilizer in high levels. Interaction of humic acid and mycorrhiza species also showed that the highest thousand seed weight belonged to 8 kg.ha-1 humic acid and G. intraradices. Samarbakhash et al. (2009 in maize showed that Inoculation with mycorrhizal fungi significantly increased the average seed weight. The highest seed yield obtained from applying 50% chemical fertilizer and 8 kg.ha-1 humic acid. Mean comparison of interaction effect of humic acid levels and mycorrhiza strains also showed that the highest seed yield belonged to 8 kg.ha-1 humic acid and G. intraradices. This increase may be attributed to the extensive root development and hyphae that reduce the distance fordiffusion of essential elements thus enhancing the nutrient absorption. Mean comparison of interaction effect of chemical fertilizer levels and mycorrhiza strains indicated that chemical fertilizer levels had no considerable effect on G. mosseae efficiency from viewpoint of seed oil content but applying 50 and 100% chemical fertilizer along with using G. intraradices significantly increased seed oil content. Mirzakhani et al. (2008 in sprig safflower showed that mycorrhiza can solubilize phosphorus in soil and enhance absorb elements by plant. Conclusion In general, among applied humic acid levels, using 8 kg.ha-1 had positive effects on the studied traits of sunflower than its other levels. Furthermore, inoculation of seeds with mycorrhiza and using

  10. Ploidy-specific symbiotic interactions: divergence of mycorrhizal fungi between cytotypes of the Gymnadenia conopsea group (Orchidaceae).

    Science.gov (United States)

    Těšitelová, Tamara; Jersáková, Jana; Roy, Mélanie; Kubátová, Barbora; Těšitel, Jakub; Urfus, Tomáš; Trávníček, Pavel; Suda, Jan

    2013-09-01

    Polyploidy is widely recognized as a major mechanism of sympatric speciation in plants, yet little is known about its effects on interactions with other organisms. Mycorrhizal fungi are among the most common plant symbionts and play an important role in plant nutrient supply. It remains to be understood whether mycorrhizal associations of ploidy-variable plants can be ploidy-specific. We examined mycorrhizal associations in three cytotypes (2x, 3x, 4x) of the Gymnadenia conopsea group (Orchidaceae), involving G. conopsea s.s. and G. densiflora, at different spatial scales and during different ontogenetic stages. We analysed: adults from mixed- and single-ploidy populations at a regional scale; closely spaced adults within a mixed-ploidy site; and mycorrhizal seedlings. All Gymnadenia cytotypes associated mainly with saprotrophic Tulasnellaceae (Basidiomycota). Nonetheless, both adults and seedlings of diploids and their autotetraploid derivatives significantly differed in the identity of their mycorrhizal symbionts. Interploidy segregation of mycorrhizal symbionts was most pronounced within a site with closely spaced adults. This study provides the first evidence that polyploidization of a plant species can be associated with a shift in mycorrhizal symbionts. This divergence may contribute to niche partitioning and facilitate establishment and co-existence of different cytotypes. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  11. Growth, cadmium uptake and accumulation of maize (Zea mays L.) under the effects of arbuscular mycorrhizal fungi.

    Science.gov (United States)

    Liu, Lingzhi; Gong, Zongqiang; Zhang, Yulong; Li, Peijun

    2014-12-01

    The effects of three arbuscular mycorrhizal fungi isolates on Cd uptake and accumulation by maize (Zea mays L.) were investigated in a planted pot experiment. Plants were inoculated with Glomus intraradices, Glomus constrictum and Glomus mosseae at three different Cd concentrations. The results showed that root colonization increased with Cd addition during a 6-week growth period, however, the fungal density on roots decreased after 9-week growth in the treatments with G. constrictum and G. mosseae isolates. The percentage of mycorrhizal colonization by the three arbuscular mycorrhizal fungi isolates ranged from 22.7 to 72.3%. Arbuscular mycorrhizal fungi inoculations decreased maize biomass especially during the first 6-week growth before Cd addition, and this inhibitory effect was less significant with Cd addition and growth time. Cd concentrations and uptake in maize plants increased with arbuscular mycorrhizal fungi colonization at low Cd concentration (0.02 mM): nonetheless, it decreased at high Cd concentration (0.20 mM) after 6-week growth period. Inoculation with G. constrictum isolates enhanced the root Cd concentrations and uptake, but G. mosseae isolates showed the opposite results at high Cd concentration level after 9 week growth period, as compared to non-mycorrhizal plants. In conclusion, maize plants inoculated with arbuscular mycorrhizal fungi were less sensitive to Cd stress than uninoculated plants. G. constrictum isolates enhanced Cd phytostabilization and G. mosseae isolates reduced Cd uptake in maize (Z. mays L.).

  12. 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.

  13. Quantification of the proliferation of arbuscular mycorrhizal fungi in soil

    Science.gov (United States)

    Zhang, Ning; Lilje, Osu; McGee, Peter

    2013-04-01

    Good soil structure is important for sustaining agricultural production and preserving functions of the soil ecosystem. Soil aggregation is a critically important component of soil structure. Stable aggregates enable water infiltration, gas exchange for biological activities of plant roots and microorganisms, living space and surfaces for soil microbes, and contribute to stabilization of organic matter and storage of organic carbon (OC) in soil. Soil aggregation involves fine roots, organic matter and hyphae of arbuscular mycorrhizal (AM) fungi. Hyphal proliferation is essential for soil aggregation and sequestration of OC in soil. We do not yet have a mechanism to directly quantify the density of hyphae in soil. Organic materials and available phosphorus are two of the major factors that influence fungi in soil. Organic materials are a source of energy for saprotrophic microbes. Fungal hyphae increase in the presence of organic matter. Phosphorus is an important element usually found in ecosystems. The low availability of phosphorus limits the biological activity of microbes. AM fungi benefit plants by delivering phosphorus to the root system. However, the density and the length of hyphae of AM fungi do not appear to be influenced by available phosphorus. A number of indirect methods have been used to visualize distribution of fungi in soil. Reliable analyses of soil are limited because of soil characteristics. Soils are fragile, and fragility limits opportunity for non-destructive analysis. The soil ecosystem is complex. Soil particles are dense and the density obscures the visualization of fungal hyphae. Fungal hyphae are relatively fine and information at the small scale (attached to the surfaces of the particles rather than grow through the spaces between them. The capacity to quantify hyphae in three-dimensional space allows a wide range of questions to now be addressed. Apart from studying mechanisms of carbon turnover, more complex processes may now be

  14. Arbuscular mycorrhizal fungi (Glomales, Zygomycota of the Bledowska Desert, Poland

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2014-01-01

    Full Text Available The occurrence of arbuscular mycorrhizal fungi (AMF; Glomales, Zygomycetes associated with plants growing in sand dune soils of the Blędowska Desert, Poland, was investigated in 1995-1997. A total of 134 mixtures of soils and roots were sampled. The mixtures represented 26 plant species in 14 families and one unrecognized plant. Spores of AMF were found in 118 soil-root mixtures. The AMF spore populations comprised 20 described species of the genera Acaulospora, Gigaspora, Glomus and Scutellospora, as well as two undescribed morphospecies of the genus Glomus. The AMF most frequently occurring in the field-collected soils were members of the genus Scutellospora The AMF spore populations comprised 20 described species in the genera Acaulospora, Gigaspora, Glomus and Scutellospora, as well as two undescribed morpho-species of the genus Glomus. The fungal species most frequently and numerously found was Scutellospora armeniaca. The fungi relatively frequently present also were A. rugosa, A. lacunosa, G. aggregatum, an undescribed Glomus 142 and Sc. dipurpurescens. The overall spore abundance of AMF averaged 69.1 and ranged from 0 to 837 in 100 g dry soil. The highest abundance of spores occurred among roots of the families Cupressaceae, followed by the Rosaceae, Asteraceae and Poaceae. Of the plant species investigated two and more times, most spores harboured Juniperus communis. The overall average species richness was 2.4 and ranged from 0 to 6 in 100 g dry soil. Of the plant species sampled at lest two times, the highest average species diversity was found in the root zone of Salix arenaria. The plant species that hosted the highest overall number of species of AMF was Festuca rubra. Trap pot cultures with soilroot mixtures collected in 1997 revealed 10 species of AMF that were not found in field soils sampled in the same year. This suggests that a great part of AMF of Błędowska Desert is represented by rarely or non-sporulating species.

  15. Micorriza arbuscular e fertilização do solo no desenvolvimento pós-transplante de mudas de sete espécies florestais Arbuscular mycorrhizal and soil fertilization on post-transplant development of outplants of seven forest species

    Directory of Open Access Journals (Sweden)

    Enrique Pouyú-Rojas

    2000-01-01

    Full Text Available Mudas de sete espécies florestais foram formadas em substrato de viveiro sem e com inoculação da mistura de fungos micorrízicos arbusculares (Glomus etunicatum, Gigaspora margarita e Acaulospora scrobiculata e transplantadas para vasos com um solo Latossolo Vermelho-Escuro com alta e baixa fertilização com NPK e submetidas, ou não, a nova inoculação. Verificou-se, após 90 dias, que tanto a inoculação na formação quanto a inoculação no transplantio garantiu elevada colonização micorrízica (>70%, estimulou o crescimento e aumentou os teores de alguns nutrientes nas plantas. Os efeitos no crescimento variaram entre as espécies e tratamentos, atingindo incrementos de matéria seca de até 800% em Colvillea racemosa. Plantas sem inoculação na formação e no transplantio, apresentaram crescimento reduzido, mesmo no solo com alta fertilidade, enquanto as plantas com inoculação na formação cresceram mais rapidamente, independentemente da reinoculação. A elevação da fertilidade não aumentou a matéria seca da parte aérea de Luehea grandiflora, Senna macranthera e Enterolobium contortisiliquum. Em Cecropia pachystachya aumentou apenas quando as mudas não foram submetidas a inoculação. Em Senna multijuga e em C. racemosa, a matéria seca da parte aérea aumentou quando as mudas foram submetidas a inoculação e em Sesbania virgata, aumentou em todos os tratamentos. Apenas C. racemosa não respondeu à inoculação no transplantio.Seedling of seven forest species were raised in conventional nursery substrate either infested or not with a mixture of arbuscular mycorrhizal fungi (Glomus etunicatum, Gigaspora margarita and Acaulospora scrobiculata and transplanted into plastic pots with a low-fertility Oxisol amended with low or high NPK-fertilization and with or without re-inoculation. It was found that either inoculation at nursery or at transplanting stage guaranteed high root colonization (>70%, growth response and

  16. Water deficit improved the capacity of arbuscular mycorrhizal fungi (AMF) for inducing the accumulation of antioxidant compounds in lettuce leaves.

    Science.gov (United States)

    Baslam, Marouane; Goicoechea, Nieves

    2012-07-01

    Lettuce, a major food crop within the European Union and the most used for the so-called 'Fourth Range' of vegetables, can associate with arbuscular mycorrhizal fungi (AMF). Mycorrhizal symbiosis can stimulate the synthesis of secondary metabolites, which may increase plant tolerance to stresses and enhance the accumulation of antioxidant compounds potentially beneficial to human health. Our objectives were to assess (1) if the application of a commercial formulation of AMF benefited growth of lettuce under different types and degrees of water deficits; (2) if water restrictions affected the nutritional quality of lettuce; and (3) if AMF improved the quality of lettuce when plants grew under reduced irrigation. Two cultivars of lettuce consumed as salads, Batavia Rubia Munguía and Maravilla de Verano, were used in the study. Four different water regimes were applied to both non-mycorrhizal and mycorrhizal plants: optimal irrigation (field capacity [FC]), a water regime equivalent to 2/3 of FC, a water regime equivalent to 1/2 of FC and a cyclic drought (CD). Results showed that mycorrhizal symbiosis improved the accumulation of antioxidant compounds, mainly carotenoids and anthocyanins, and to a lesser extent chlorophylls and phenolics, in leaves of lettuce. These enhancements were higher under water deficit than under optimal irrigation. Moreover, shoot biomass in mycorrhizal lettuces subjected to 2/3 of FC were similar to those of non-mycorrhizal plants cultivated under well-watered conditions. In addition, lettuces subjected to 2/3 FC had similar leaf RWC than their respective well-watered controls, regardless of mycorrhizal inoculation. Therefore, results suggest that mycorrhizal symbiosis can improve quality of lettuce and may allow restrict irrigation without reducing production.

  17. Highly diverse and spatially heterogeneous mycorrhizal symbiosis in a rare epiphyte is unrelated to broad biogeographic or environmental features.

    Science.gov (United States)

    Kartzinel, Tyler R; Trapnell, Dorset W; Shefferson, Richard P

    2013-12-01

    Symbiotic interactions are common in nature. In dynamic or degraded environments, the ability to associate with multiple partners (i.e. broad specificity) may enable species to persist through fluctuations in the availability of any particular partner. Understanding how species interactions vary across landscapes is necessary to anticipate direct and indirect consequences of environmental degradation on species conservation. We asked whether mycorrhizal symbiosis by populations of a rare epiphytic orchid (Epidendrum firmum) is related to geographic or environmental heterogeneity. The latter would suggest that interactions are governed by environmental conditions rather than historic isolation of populations and/or mycorrhizal fungi. We used DNA-based methods to identify mycorrhizal fungi from eleven E. firmum populations in Costa Rica. We used molecular and phylogenetic analyses to compare associations. Epidendrum firmum exhibited broad specificity, associating with diverse mycorrhizal fungi, including six Tulasnellaceae molecular operational taxonomic units (MOTUs), five Sebacinales MOTUs and others. Notably, diverse mycorrhizal symbioses formed in disturbed pasture and roadside habitats. Mycorrhizal fungi exhibited significant similarity within populations (spatial and phylogenetic autocorrelation) and significant differences among populations (phylogenetic community dissimilarity). However, mycorrhizal symbioses were not significantly associated with biogeographic or environmental features. Such unexpected heterogeneity among populations may result from complex combinations of fine-scale environmental factors and macro-evolutionary patterns of change in mycorrhizal specificity. Thus, E. firmum exhibits broad specificity and the potential for opportunistic associations with diverse fungi. We suggest that these characteristics could confer symbiotic assurance when mycorrhizal fungi are stochastically available, which may be crucial in dynamic or disturbed

  18. Influence of Arbuscular Mycorrhizal Fungi and Drought Stress on Some Macro Nutrient Uptake in Three Leek Genotypes with Different Root Morphology

    Directory of Open Access Journals (Sweden)

    N. Ghasem Jokar

    2016-02-01

    Full Text Available Introduction: Drought stress is one of the main problems in agricultural productions in arid and semiarid regions such as Iran. Lack of water influences on most of plant physiological processes such as photosynthes, cellular development and uptake and transmission of nutrients in plants. Some approaches such as selection of resistance cultivars to drought stress, and selection of dripped irrigation have been applied in order to increase the irrigation efficiency. In recent years, biological approaches such as mycorrhizal symbiosis have been used to alleviate the detrimental effects of drought stress. Mycorrhizal symbioses increase the absorption of nutrients, especially phosphorus, and reduce the adverse effects of environmental stresses. It can also improve the host plant growth and yield. The percentage of mycorrhizal dependency of host plants depends on different environmental factors (such as light intensity, temperature, soil conditions, as well as morphological and physiological characteristics of plants. 1n 2010, a greenhouse pot experiment was conducted at University of Agriculture and Natural Resources Ramin. The effect of mycorrhizal inoculation on root morphology of three leek genotypes and uptake of phosphorous, calcium and potassium in shoot and root were studied. Materials and Methods: The experiment was conducted in a completely randomized design consisting of a 3×3×2 factorial combination. Experimental factors included three levels of soil moisture (40, 60 and 80% of available water in the soil, two mycorrhizal status (with and without fungus Glomus intraradices and three leek genotypes including: Shadegan (with low root branching, short and thin root length, Esfahan (with abundant root branching and long root length and Porrum (with low root branching, short and thick root length. The treatments were replicated four times. The soil was autoclaved at 121°C and15 PSI for 15 minutes and gently packed into PVC pots, 200 mm long

  19. Foliar Application of Phosphorus Has Minimal Impact on 'Pinot noir' Growth, Mycorrhizal Colonization, or Fruit Quality

    Science.gov (United States)

    Grapevines grown in low phosphorus (P) soils typical of western Oregon vineyards may benefit from additional P applied to the canopy using foliar sprays. Alternatively, vines may be negatively affected by foliar P sprays because lower root colonization by arbuscular mycorrhizal fungi (AMF) could red...

  20. Arbuscular mycorrhizal fungi colonize non-fixing root nodules of several legume species.

    NARCIS (Netherlands)

    Scheublin, T.R.; van der Heijden, M.G.A.

    2006-01-01

    • Many legumes form tripartite symbiotic associations with rhizobia and arbuscular mycorrhizal fungi (AMF). Rhizobia are located in root nodules and provide the plant with fixed atmospheric nitrogen, while AMF colonize plant roots and deliver several essential nutrients to the plant. Recent studies

  1. Arbuscular mycorrhizal fungi colonize nonfixing roots nodules of several legume species.

    NARCIS (Netherlands)

    Scheublin, T.R.; van der Heijden, M.G.A.

    2006-01-01

    • Many legumes form tripartite symbiotic associations with rhizobia and arbuscular mycorrhizal fungi (AMF). Rhizobia are located in root nodules and provide the plant with fixed atmospheric nitrogen, while AMF colonize plant roots and deliver several essential nutrients to the plant. Recent studies

  2. Inoculation of grass and tree seedlings used for reclaiming eroded areas in Iceland with mycorrhizal dungi

    Czech Academy of Sciences Publication Activity Database

    Batkhuugyin, Enkhtuya; Óskarsson, Ú.; Dodd, J. C.; Vosátka, Miroslav

    2003-01-01

    Roč. 38, - (2003), s. 209-222 ISSN 0015-5551 R&D Projects: GA AV ČR KSK6005114; GA ČR GA526/99/0895 Institutional research plan: CEZ:AV0Z6005908 Keywords : arbuscular mycorrhizal fungi * ectomycorrhizal fungi * volcanic ash Subject RIV: EF - Botanics Impact factor: 1.057, year: 2003

  3. Mycorrhizal responsiveness of aerobic rice genotypes is negatively correlated with their zinc uptake when nonmycorhizal

    NARCIS (Netherlands)

    Gao, X.; Kuyper, T.W.; Zou, C.; Zhang, F.; Hoffland, E.

    2007-01-01

    Plant Zn uptake from low Zn soils can be increased by Zn-mobilizing chemical rhizosphere processes. We studied whether inoculation with arbuscular mycorrhizal fungi (AMF) can be an additional or an alternative strategy. We determined the effect of AMF inoculation on growth performance and Zn uptake

  4. Variation in phosphorus acquisition efficiency among maize varieties as related to mycorrhizal functioning

    NARCIS (Netherlands)

    Wang, X.X.

    2016-01-01

    Phosphorus (P) is a main limiting factor for agricultural production, but overusing P fertilizer has brought serious environmental damages in China. Improving P acquisition efficiency of agricultural crops is an urgent topic. It has been proven repeatedly that arbuscular mycorrhizal fungi (AMF) and

  5. Efflux of hydraulically lifted water from mycorrhizal fungal hyphae during imposed drought

    Science.gov (United States)

    Querejeta, José Ignacio; Allen, Michael F

    2008-01-01

    Apart from improving plant and soil water status during drought, it has been suggested that hydraulic lift (HL) could enhance plant nutrient capture through the flow of mineral nutrients directly from the soil to plant roots, or by maintaining the functioning of mycorrhizal fungi. We evaluated the extent to which the diel cycle of water availability created by HL covaries with the efflux of HL water from the tips of extramatrical (external) mycorrhizal hyphae, and the possible effects on biogeochemical processes. Phenotypic mycorrhizal fungal variables, such as total and live hyphal lengths, were positively correlated with HL efflux from hyphae, soil water potential (dawn), and plant response variables (foliar 15N). The efflux of HL water from hyphae was also correlated with bacterial abundance and soil enzyme activity (P), and the moistening of soil organic matter. Such findings indicate that the efflux of HL water from the external mycorrhizal mycelia may be a complementary explanation for plant nutrient acquisition and survival during drought. PMID:19704776

  6. Facilitation between woody and herbaceous plants that associate with arbuscular mycorrhizal fungi in temperate European forests.

    Science.gov (United States)

    Veresoglou, Stavros D; Wulf, Monika; Rillig, Matthias C

    2017-02-01

    In late-successional environments, low in available nutrient such as the forest understory, herbaceous plant individuals depend strongly on their mycorrhizal associates for survival. We tested whether in temperate European forests arbuscular mycorrhizal (AM) woody plants might facilitate the establishment of AM herbaceous plants in agreement with the mycorrhizal mediation hypothesis. We used a dataset spanning over 400 vegetation plots in the Weser-Elbe region (northwest Germany). Mycorrhizal status information was obtained from published resources, and Ellenberg indicator values were used to infer environmental data. We carried out tests for both relative richness and relative abundance of herbaceous plants. We found that the subset of herbaceous individuals that associated with AM profited when there was a high cover of AM woody plants. These relationships were retained when we accounted for environmental filtering effects using path analysis. Our findings build on the existing literature highlighting the prominent role of mycorrhiza as a coexistence mechanism in plant communities. From a nature conservation point of view, it may be possible to promote functional diversity in the forest understory through introducing AM woody trees in stands when absent.

  7. Indicator species and co-occurrence in communities of arbuscular mycorrhizal fungi at the European scale

    NARCIS (Netherlands)

    Bouffaud, Marie Lara; Creamer, Rachel E.; Stone, Dote; Plassart, Pierre; Tuinen, van Diederik; Lemanceau, Philippe; Wipf, Daniel; Redecker, Dirk

    2016-01-01

    Utilizing a European transect of 54 soil samples, comprising of grasslands, arable and forest sites, we analyzed community composition of Arbuscular Mycorrhizal Fungi (AMF, Glomeromycota) using pyrosequencing of the Internal Transcribed Spacer region. We found a significant influence of

  8. Mycorrhizal symbiosis and seedling performance of the frankincense tree (Boswellia papyrifera)

    NARCIS (Netherlands)

    Hizikias, E.B.

    2011-01-01

    Arid areas are characterized by a seasonal climate with a long dry period. In such stressful environment, resource availability is driven by longterm and shorterm rainfall pulses. Arbuscular Mycorrhizal (AM) fungi enhance access to moisture and nutrients and thereby influence plant performance.

  9. BIOMETRIC PARAMETERS OF FIELD GROWN SESAME INFLUENCED BY ARBUSCULAR MYCORRHIZAL INOCULATION, ROCK PHOSPHATE FERTILIZATION AND IRRIGATION

    Directory of Open Access Journals (Sweden)

    V.S. Harikumar

    2017-08-01

    Full Text Available The aim of the study was to assess the effect of inoculation with arbuscular mycorrhizal fungi (AMF and rock phosphate (RP fertilization on biometric parameters and mycorrhizal colonization of field grown sesame under rainfed and irrigated conditions. Inoculation of AMF Funneliformis dimorphicus improved the biometric parameters of the crop such as leaf area (LA, leaf area index (LAI, specific leaf weight (SLW, net assimilation rate (NAR, oil index (OI as well as mycorrhizal colonization (%F in roots. Mycorrhizal inoculation however, did not give any positive response on harvest index (HI. LA, LAI and OI and %F showed a general increment in treatments of no added P (P0, while the other parameters such as SLW and NAR were improved by the application of RP at half the recommended dose (P50. HI did not respond to RP fertilization. Most of the parameters (LA, LAI, NAR, %F showed higher values under rainfed condition than irrigated condition whereas, SLW, HI and OI improved significantly under irrigated condition. Results indicated that the inoculation of AMF to field grown sesame can compensate for 50% of the recommended P fertilizer under a need based irrigation schedule, without affecting the biometric parameters.

  10. 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.

    2016-01-01

    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

  11. Arbuscular mycorrhizal fungal species differ in their effect on nutrient leaching

    NARCIS (Netherlands)

    Köhl, Luise; van der Heijden, Marcel G A

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi have been shown to play a crucial role in nutrient cycling and can reduce nutrient losses after rain induced leaching events. It is still unclear whether nutrient leaching losses vary depending on the AM fungal taxa that are present in soil. Using experimental

  12. Mycorrhizal associations in Ailanthus altissima (Simaroubaceae) from forested and non-forested sites

    Science.gov (United States)

    Cynthia D. Huebner; Carolyn McQuattie; Joanne Rebbeck

    2007-01-01

    Ailanthus altissima tree seedlings were excavated from each of two habitats: (1) a forest adjacent to a trail and stream and (2) a non-forested steep, barren slope adjacent to a major highway. Each seedling root system was examined for colonization by mycorrhizal structures using light microscopy and transmission electron microscopy. The roots were...

  13. Arbuscular mycorrhizal symbiosis alleviates drought stress imposed on Knautia arvensis plants in serpentine soil

    Czech Academy of Sciences Publication Activity Database

    Doubková, Pavla; Vlasáková, E.; Sudová, Radka

    2013-01-01

    Roč. 370, 1-2 (2013), s. 149-161 ISSN 0032-079X R&D Projects: GA AV ČR KJB600050812 Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal fungi * drought * serpentine soil Subject RIV: EF - Botanics Impact factor: 3.235, year: 2013

  14. Carbon flow from plant to arbuscular mycorrhizal fungi is reduced under phosphorus fertilization

    Czech Academy of Sciences Publication Activity Database

    Konvalinková, Tereza; Püschel, David; Řezáčová, Veronika; Gryndlerová, Hana; Jansa, Jan

    2017-01-01

    Roč. 419, 1-2 (2017), s. 319-333 ISSN 0032-079X R&D Projects: GA MŠk(CZ) LK11224; GA ČR(CZ) GA14-19191S Institutional support: RVO:61388971 Keywords : Arbuscular mycorrhiza * Carbon allocation * Mycorrhizal cost Subject RIV: EE - Microbiology, Virology Impact factor: 3.052, year: 2016

  15. Differential benefits of arbuscular mycorrhizal and ectomycorrhizal infection of salix repens

    NARCIS (Netherlands)

    Heijden, van der E.W.

    2001-01-01

    The functional significance of arbuscular mycorrhiza (AM) and ectomycorrhiza (EcM) for Salix repens, a dual mycorrhizal plant, was investigated over three harvest periods (12, 20 and 30 weeks). Cuttings of S. repens were collected in December (low shoot P) and March (high shoot P). Glomus mosseae

  16. Decomposition of /sup 14/C-labelled lignin, holocellulose and lignocellulose by mycorrhizal fungi

    Energy Technology Data Exchange (ETDEWEB)

    Trojanowski, J.; Huettermann, A.; Haider, K.

    1984-01-01

    Five different species of known ecto-mycorrhizal fungi: Cenococcum geophilum, Amanita muscaria, Tricholoma aurantium, Rhizopogon luteolus and Rhizopogon roseolus were studied for their ability to metabolize the major components of plant cell walls. All strains were able to decompose /sup 14/C-labelled plant lignin, /sup 14/C-lignocellulose and /sup 14/C-DHP-lignin at a rate which was lower than the one observed for the known white rot fungi Heterobasidion annosum and Sporotrichum pulverulentum. Also /sup 14/C-(U)-holocellulose was relatively less degradable for the mycorrhizal fungi than for the white rotters. On the other hand, aromatic monomers like /sup 14/C-vanillic acid were decomposed to a much higher extent by two species of mycorrhizal fungi compared to the activity observed for Heterobasidion annosum. The results of the experiments reveal that these stains of mycorrhizal fungi are well able to utilize the major components of plant material and thus can contribute to litter decomposition in the forest floor.

  17. 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

  18. 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...

  19. Arbuscular mycorrhizal fungi differentially affect the response to high zinc concentrations of two registered poplar clones

    Energy Technology Data Exchange (ETDEWEB)

    Lingua, Guido [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy)], E-mail: guido.lingua@mfn.unipmn.it; Franchin, Cinzia [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Todeschini, Valeria [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy); Castiglione, Stefano [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Biondi, Stefania [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Burlando, Bruno [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy); Parravicini, Valerio [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Torrigiani, Patrizia [Dipartimento di Biologia evoluzionistica sperimentale, Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Berta, Graziella [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale ' Amedeo Avogadro' , Via Bellini 25/G, I-15100 Alessandria (Italy)

    2008-05-15

    The effects of a high concentration of zinc on two registered clones of poplar (Populus alba Villafranca and Populus nigra Jean Pourtet), inoculated or not with two arbuscular mycorrhizal fungi (Glomus mosseae or Glomus intraradices) before transplanting them into polluted soil, were investigated, with special regard to the extent of root colonization by the fungi, plant growth, metal accumulation in the different plant organs, and leaf polyamine concentration. Zinc accumulation was lower in Jean Pourtet than in Villafranca poplars, and it was mainly translocated to the leaves; the metal inhibited mycorrhizal colonization, compromised plant growth, and, in Villafranca, altered the putrescine profile in the leaves. Most of these effects were reversed or reduced in plants pre-inoculated with G. mosseae. Results indicate that poplars are suitable for phytoremediation purposes, confirming that mycorrhizal fungi can be useful for phytoremediation, and underscore the importance of appropriate combinations of plant genotypes and fungal symbionts. - Inoculation with arbuscular mycorrhizal fungi can improve poplar tolerance to heavy metals in phytoremediation programmes.

  20. An exotic grass disrupts mycorrhizal fungi which increases the mortality of Artemisia tridentata

    Science.gov (United States)

    Invasive plant species are capable of changing the community composition of arbuscular mycorrhizal fungi (AMF). Changes to AMF communities may contribute to the net negative impact of invasives on resident plants. Here we compared the AMF communities of the invasive grass Agropyron cristatum acros...

  1. Mycorrhizal associations of trees have different indirect effects on organic matter decomposition

    Science.gov (United States)

    Melanie K. Taylor; Richard A. Lankau; Nina Wurzburger; Franciska de Vries

    2016-01-01

    1. Organic matter decomposition is the main process by which carbon (C) is lost from terrestrialecosystems, and mycorrhizal associations of plants (i.e. arbuscular mycorrhizas (AM) and ectomycorrhizas(ECM)) may have different indirect effects on this loss pathway. AM and ECM plants differin the soil...

  2. Inoculation of fumigated nursery beds and containers with arbuscular mycorrhizal products for eastern redcedar production

    Science.gov (United States)

    Michelle M. Cram; Stephen W. Fraedrich

    2015-01-01

    Commercially available arbuscular mycorrhizal (AM) products were applied at an operational rate to eastern redcedar (Juniperus virginiana L.) nursery beds and containers to evaluate seedling growth and colonization responses. A field study at the Augusta Forestry Center in Crimora, VA, and a companion container study were initiated in the fall of 2012. MycoApply® Endo...

  3. Effect of biochar soil-amendments on Allium porrum growth, arbuscular mycorrhizal fungus colonization

    Science.gov (United States)

    Aims: Examine the interaction of biochar addition and arbuscular mycorrhizal [AM] fungus inoculation upon growth and Zn and Cu uptake by Allium porrum L. in heavy metal amended soil mix, and relate these responses to physicochemical properties of the biochars. Methods: The experiment was a complete ...

  4. Establishment and effectiveness of inoculated arbuscular mycorrhizal fungi in agricultural soils

    NARCIS (Netherlands)

    Köhl, Luise; Lukasiewicz, Catherine E.; Van der Heijden, Marcel G A|info:eu-repo/dai/nl/240923901

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) are promoted as biofertilizers for sustainable agriculture. So far, most researchers have investigated the effects of AMF on plant growth under highly controlled conditions with sterilized soil, soil substrates or soils with low available P or low inoculum

  5. Mycorrhizal ecology and evolution : The past, the present, and the future

    NARCIS (Netherlands)

    van der Heijden, Marcel G A|info:eu-repo/dai/nl/240923901; Martin, Francis M.; Selosse, Marc André; Sanders, Ian R.

    2015-01-01

    Almost all land plants form symbiotic associations with mycorrhizal fungi. These below-ground fungi play a key role in terrestrial ecosystems as they regulate nutrient and carbon cycles, and influence soil structure and ecosystem multifunctionality. Up to 80% of plant N and P is provided by

  6. Mycorrhizal Fungal Community of Poplars Growing on Pyrite Tailings Contaminated Site near the River Timok

    Directory of Open Access Journals (Sweden)

    Marina Katanić

    2015-06-01

    Full Text Available Background and Purpose: Mycorrhizal fungi are of high importance for functioning of forest ecosystems and they could be used as indicators of environmental stress. The aim of this research was to analyze ectomycorrhizal community structure and to determine root colonization rate with ectomycorrhizal, arbuscular mycorrhizal and endophytic fungi of poplars growing on pyrite tailings contaminated site near the river Timok (Eastern Serbia. Materials and Methods: Identification of ectomycorrhizal types was performed by combining morphological and anatomical characterization of ectomycorrhizae with molecular identification approach, based on sequencing of the nuclear ITS rRNA region. Also, colonization of poplar roots with ectomycorrhizal, arbuscular mycorrhizal and dark septated endophytic fungi were analysed with intersection method. Results and Conclusions: Physico-chemical analyses of soil from studied site showed unfavourable water properties of soil, relatively low pH and high content of heavy metals (copper and zinc. In investigated samples only four different ectomycorrhizal fungi were found. To the species level were identified Thelephora terrestris and Tomentella ellisi, while two types remained unidentified. Type Thelephora terrestris made up 89% of all ectomycorrhizal roots on studied site. Consequently total values of Species richness index and Shannon-Weaver diversity index were 0.80 and 0.43, respectively. No structures of arbuscular mycorrhizal fungi were recorded. Unfavourable environmental conditions prevailing on investigated site caused decrease of ectomycorrhizal types diversity. Our findings point out that mycorrhyzal fungal community could be used as an appropriate indicator of environmental changes.

  7. Mycorrhizal effects on nutrient cycling, nutrient leaching and N2O production in experimental grassland

    NARCIS (Netherlands)

    Bender, S.F.; Conen, F.; van der Heijden, M.G.A.

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) can enhance plant nutrition and growth. However, their contribution to nutrient cycling in ecosystems is still poorly understood. Using experimental grassland microcosms filled with two different soil types (pasture and heath soil) and fertilized with different N

  8. Shifts in mycorrhizal fungi during the evolution of autotrophy to mycoheterotrophy in Cymbidium (Orchidaceae).

    Science.gov (United States)

    Ogura-Tsujita, Yuki; Yokoyama, Jun; Miyoshi, Kazumitsu; Yukawa, Tomohisa

    2012-07-01

    Mycoheterotrophic plants, which completely depend upon mycorrhizal fungi for their nutrient supply, have unusual associations with fungal partners. The processes involved in shifts in fungal associations during cladogenesis of plant partners from autotrophy to mycoheterotrophy have not been demonstrated using a robust phylogenetic framework. Consequences of a mycorrhizal shift were examined in Cymbidium (Orchidaceae) using achlorophyllous and sister chlorophyllous species. Fungal associates of the two achlorophyllous mycoheterotrophs (C. macrorhizon and C. aberrans), their close relatives, the chlorophyllous mixotrophs (C. goeringii and C. lancifolium) and an outgroup, the chlorophyllous autotroph C. dayanum, were identified by internal transcribed spacers of the nuclear ribosomal DNA sequences. Molecular identification of mycorrhizal fungi revealed: (1) the outgroup autotroph is predominantly dependent on saprobic Tulasnellaceae, (2) the mixotrophs associate with the Tulasnellaceae and ectomycorrhizal groups including the Sebacinales, Russulaceae, Thelephoraceae and Clavulinaceae, and (3) the two mycoheterotrophs are mostly specialized with ectomycorrhizal Sebacinales. Fungal partners in Cymbidium have shifted from saprobic to ectomycorrhizal fungi via a phase of coexistence of both nutritional types of fungi. These three phases correspond to the evolution from autotrophy to mycoheterotrophy via mixotrophy in Cymbidium. We demonstrate that shifts in mycorrhizal fungi correlate with the evolution of nutritional modes in plants. Furthermore, gradual shifts in fungal partners through a phase of coexistence of different types of mycobionts may play a crucial role in the evolution of mycoheterotrophic plants.

  9. pH measurement of tubular vacuoles of an arbuscular mycorrhizal fungus, Gigaspora margarita.

    Science.gov (United States)

    Funamoto, Rintaro; Saito, Katsuharu; Oyaizu, Hiroshi; Aono, Toshihiro; Saito, Masanori

    2015-01-01

    Arbuscular mycorrhizal fungi play an important role in phosphate supply to the host plants. The fungal hyphae contain tubular vacuoles where phosphate compounds such as polyphosphate are accumulated. Despite their importance for the phosphate storage, little is known about the physiological properties of the tubular vacuoles in arbuscular mycorrhizal fungi. As an indicator of the physiological state in vacuoles, we measured pH of tubular vacuoles in living hyphae of arbuscular mycorrhizal fungus Gigaspora margarita using ratio image analysis with pH-dependent fluorescent probe, 6-carboxyfluorescein. Fluorescent images of the fine tubular vacuoles were obtained using a laser scanning confocal microscope, which enabled calculation of vacuolar pH with high spatial resolution. The tubular vacuoles showed mean pH of 5.6 and a pH range of 5.1-6.3. These results suggest that the tubular vacuoles of arbuscular mycorrhizal fungi have a mildly acidic pH just like vacuoles of other fungal species including yeast and ectomycorrhizal fungi.

  10. Nonlegumes, legumes, and root nodules harbor different arbuscular mycorrhizal fungal communities.

    NARCIS (Netherlands)

    Scheublin, T.R.; Ridgway, K.P.; Young, J.P.W.; van der Heijden, M.G.A.

    2004-01-01

    Legumes are an important plant functional group since they can form a tripartite symbiosis with nitrogen-fixing Rhizobium bacteria and phosphorus-acquiring arbuscular mycorrhizal fungi (AMF). However, not much is known about AMF community composition in legumes and their root nodules. In this study,

  11. Mycorrhizal Associations and Trophic Modes in Coexisting Orchids: An Ecological Continuum between Auto- and Mixotrophy.

    Science.gov (United States)

    Jacquemyn, Hans; Waud, Michael; Brys, Rein; Lallemand, Félix; Courty, Pierre-Emmanuel; Robionek, Alicja; Selosse, Marc-André

    2017-01-01

    Two distinct nutritional syndromes have been described in temperate green orchids. Most orchids form mycorrhizas with rhizoctonia fungi and are considered autotrophic. Some orchids, however, associate with fungi that simultaneously form ectomycorrhizas with surrounding trees and derive their carbon from these fungi. This evolutionarily derived condition has been called mixotrophy or partial mycoheterotrophy and is characterized by 13 C enrichment and high N content. Although it has been suggested that the two major nutritional syndromes are clearly distinct and tightly linked to the composition of mycorrhizal communities, recent studies have challenged this assumption. Here, we investigated whether mycorrhizal communities and nutritional syndromes differed between seven green orchid species that co-occur under similar ecological conditions (coastal dune slacks). Our results showed that mycorrhizal communities differed significantly between orchid species. Rhizoctonia fungi dominated in Dactylorhiza sp., Herminium monorchis , and Epipactis palustris , which were autotrophic based on 13 C and N content. Conversely, Liparis loeselii and Epipactis neerlandica associated primarily with ectomycorrhizal fungi but surprisingly, 13 C and N content supported mixotrophy only in E. neerlandica . This, together with the finding of some ectomycorrhizal fungi in rhizoctonia-associated orchids, suggests that there exists an ecological continuum between the two syndromes. The presence of a large number of indicator species associating with individual orchid species further confirms previous findings that mycorrhizal fungi may be important factors driving niche-partitioning in terrestrial orchids and therefore contribute to orchid coexistence.

  12. Presence and identity of arbuscular mycorrhizal fungi influence competitive interactions between plant species.

    NARCIS (Netherlands)

    Scheublin, T.R.; van Logtestijn, R.S.P; van der Heijden, M.G.A.

    2007-01-01

    1 Competition for nutrients is an important factor structuring plant communities. Plant symbionts such as arbuscular mycorrhizal fungi (AMF) can have considerable influence on nutrient uptake and are therefore likely to influence plant competition. In this study we investigated the influence of

  13. Simulated nitrogen deposition affects community structure of arbuscular mycorrhizal fungi in northern hardwood forests

    Science.gov (United States)

    Linda T.A. Van Diepen; Erik Lilleskov; Kurt S. Pregitzer

    2011-01-01

    Our previous investigation found elevated nitrogen deposition caused declines in abundance of arbuscular mycorrhizal fungi (AMF) associated with forest trees, but little is known about how nitrogen affects the AMF community composition and structure within forest ecosystems. We hypothesized that N deposition would lead to significant changes in the AMF community...

  14. Plant hormones in arbuscular mycorrhizal symbioses: an emerging role for gibberellins.

    Science.gov (United States)

    Foo, Eloise; Ross, John J; Jones, William T; Reid, James B

    2013-05-01

    Arbuscular mycorrhizal symbioses are important for nutrient acquisition in >80 % of terrestrial plants. Recently there have been major breakthroughs in understanding the signals that regulate colonization by the fungus, but the roles of the known plant hormones are still emerging. Here our understanding of the roles of abscisic acid, ethylene, auxin, strigolactones, salicylic acid and jasmonic acid is discussed, and the roles of gibberellins and brassinosteroids examined. Pea mutants deficient in gibberellins, DELLA proteins and brassinosteroids are used to determine whether fungal colonization is altered by the level of these hormones or signalling compounds. Expression of genes activated during mycorrhizal colonization is also monitored. Arbuscular mycorrhizal colonization of pea roots is substantially increased in gibberellin-deficient na-1 mutants compared with wild-type plants. This is reversed by application of GA3. Mutant la cry-s, which lacks gibberellin signalling DELLA proteins, shows reduced colonization. These changes were parallelled by changes in the expression of genes associated with mycorrhizal colonization. The brassinosteroid-deficient lkb mutant showed no change in colonization. Biologically active gibberellins suppress arbuscule formation in pea roots, and DELLA proteins are essential for this response, indicating that this role occurs within the root cells.

  15. 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

  16. Arbuscular mycorrhizal impacts on competitive interactions between Acacia etbaica and Boswellia papyrifera seedlings under drought stress

    NARCIS (Netherlands)

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

    2014-01-01

    Aims Arbuscular mycorrhizal fungi can have a substantial effect on the water and nutrient uptake by plants and the competition between plants in harsh environments where resource availability comes in pulses. In this study we focus on interspecific competition between Acaia etbaica and Boswellia

  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

    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

  18. Large-scale diversity patterns in spore communities of Arbuscular mycorrhizal fungi [Chapter 2

    Science.gov (United States)

    Javier Alvarez-Sanchez; Nancy C. Johnson; Anita Antoninka; V. Bala Chaudhary; Matthew K. Lau; Suzanne M. Owen; Patricia Gauadarrama; Silvia. Castillo

    2010-01-01

    Surprising little is known about the factors controlling Arbuscular Mycorrhizal (AM) fungal diversity and distribution patterns. A better understanding of these factors is necessary before mycorrhizas can be effectively managed for their benefits in ecosystem restoration and agriculture. The goal of this chapter is to examine the relationships between AM fungal...

  19. EFFECTS OF MYCORRHIZAL FUNGI ON IN-VITRO NITROGEN RESPONSE OF SOME DUTCH INDIGENOUS ORCHID SPECIES

    NARCIS (Netherlands)

    DIJK, E; ECK, ND

    The effect of mycorrhizal infection on the response to mineral nitrogen was studied in Orchis morio L., Dactylorhiza praetermissa (Druce) Soo var. junialis (Vermin.) Sengh., Dactylorhiza majalis (Reichb.) Hunt & Summerh., and Dactylorhiza incarnara (L.) Soo, using two strains of Ceratorhiza sp. and

  20. Arbuscular mycorrhizal fungi and dark septate fungi in plants associated with aquatic environments

    Directory of Open Access Journals (Sweden)

    Josy Fraccaro de Marins

    Full Text Available ABSTRACT There have been several reports of symbionts in the roots of plants that live in aquatic environments. Arbuscular mycorrhizal fungi (AMF are the most common microsymbionts and possibly recolonized the aquatic environment together with plants; however, their functions and the extent of their benefits are unclear. Furthermore, the presence of other groups of fungi, such as dark septate fungi (DSF, with functions supposedly analogous to those of mycorrhizal fungi, has also been reported. The present work provides a compilation of data regarding the presence of arbuscular mycorrhizae in plants from, or under the influence of, aquatic environments, and co-colonization by AMF and DSF. Forty species of non-vascular plants, ferns, fern allies, and gymnosperms from 15 families, and 659 species of angiosperms from 87 families were investigated. From the first group (non-flowering plants 57 % of the species showed arbuscular mycorrhizal structures in their tissues or roots, whereas among the second group (flowering plants 71% had such structures. Among the mycorrhizal angiosperms, 52 % showed arbuscules in their roots. DSF were found in 1% of non-flowering plants and 5 % of angiosperms. All of these are discussed in this review.