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Sample records for controlling arbuscular mycorrhiza

  1. Arbuscular Mycorrhiza

    Science.gov (United States)

    Martin, Holger; Cohen, David; Fitz, Michael; Wipf, Daniel

    2007-01-01

    The intimate arbuscular mycorrhiza (AM) association between roots and obligate symbiotic Glomeromycota (‘AM fungi’) ‘feeds’ about 80% of land plants. AM forming fungi supply land plants with inorganic nutrients and have an enormous impact on terrestrial ecosystems. In return, AM fungi obtain up to 20% of the plant-fixed CO2, putatively as monosaccharides. In a recent work we have reported the characterization of the first glomeromycotan monosaccharide transporter, GpMST1, and its gene sequence. We discuss that AM fungi might take up sugars deriving from plant cell-wall material. The GpMST1 sequence delivers valuable data for the isolation of orthologues from other AM fungi and may eventually lead to the understanding of C-flows in the AM. PMID:19704624

  2. Utilization of arbuscular mycorrhiza by system management

    OpenAIRE

    Kahiluoto, Helena; Vestberg, Mauritz

    2000-01-01

    Mycorrhiza is an ecosystem service which can be relied on and favoured, but also impaired or irreversibly lost depending on the production system. Arbuscular mycorrhiza (AM) deserves to be considered in development of sustainable farming systems as well as in breeding and soil quality assessment programmes serving sustainable agriculture. AM effectiveness in field soils can be assessed using a standardized bioassay.

  3. ARBUSCULAR MYCORRHIZAE: A DIVERSE PERSONALITY

    Directory of Open Access Journals (Sweden)

    THANGASWAMY SELVARAJ

    2006-12-01

    Full Text Available Arbuscular mycorrhizae (AM are benefi cial symbionts for plant growth. They are associated with higher plants by a symbiotic association, and benefi t plants in uptake of phosphorus nutrients, production of growth hormones, increase of proteins, lipids and sugars levels, helps in heavy metal binding, salinity tolerance, disease resistance, and even in the uptake of radionuclides. Mycorrhizal genes also applicable in improvement of crop plants, due to their delivery in to plants, by a process called, particle bombardment. The comibined association of mycorrhizal fungi and Rhizobium, with legume plants, as a symbiotic association, increased the beneficial aspects comparatively more than their single associations with the host plants. This review focuses on all beneficial aspects of AM fungi, regarding plant growth.

  4. [Regulatory genes of garden pea (Pisum sativum L.) controlling the development of nitrogen-fixing nodules and arbuscular mycorrhiza: a review of basic and applied aspects

    DEFF Research Database (Denmark)

    Borisov, A Iu; Vasil'chikov, A G; Voroshilova, V A

    2007-01-01

    The review sums up the long experience of the authors and other researchers in studying the genetic system of garden pea (Pisum sativum L.), which controls sthe development of nitrogen-fixing symbiosis and arbuscular mycorrhiza. A justified phenotypic classification of pea mutants is presented....... Progress in identifying and cloning symbiotic genes is adequately reflected. The feasibility of using double inoculation as a means of increasing the plant productivity is demonstrated, in which the potential of a tripartite symbiotic system (pea plants-root nodule bacteria-arbuscular mycorrhiza...

  5. Arbuscular fungi and mycorrhizae of agricultural soils of the Western Pomerania. Part I. Occurrence of arbuscular fungi and mycorrhizae

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    Anna Iwaniuk

    2014-08-01

    Full Text Available This paper presents results of three-year investigations on the occurrence of arbuscular mycorrhizal fungi and arbuscular mycorrhizae of the phylum Glomeromycota in agricultural soils of the Western Pomerania, north-western Poland. The occurrence of these fungi was determined basing on soil-root mixtures collected from both the field and trap cultures.

  6. Arbuscular fungi and mycorrhizae of agricultural soils of the Western Pomerania. Part I. Occurrence of arbuscular fungi and mycorrhizae

    OpenAIRE

    Anna Iwaniuk; Janusz Błaszkowski

    2014-01-01

    This paper presents results of three-year investigations on the occurrence of arbuscular mycorrhizal fungi and arbuscular mycorrhizae of the phylum Glomeromycota in agricultural soils of the Western Pomerania, north-western Poland. The occurrence of these fungi was determined basing on soil-root mixtures collected from both the field and trap cultures.

  7. Arbuscular mycorrhizas are present on Spitsbergen.

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    Newsham, K K; Eidesen, P B; Davey, M L; Axelsen, J; Courtecuisse, E; Flintrop, C; Johansson, A G; Kiepert, M; Larsen, S E; Lorberau, K E; Maurset, M; McQuilkin, J; Misiak, M; Pop, A; Thompson, S; Read, D J

    2017-07-10

    A previous study of 76 plant species on Spitsbergen in the High Arctic concluded that structures resembling arbuscular mycorrhizas were absent from roots. Here, we report a survey examining the roots of 13 grass and forb species collected from 12 sites on the island for arbuscular mycorrhizal (AM) colonisation. Of the 102 individuals collected, we recorded AM endophytes in the roots of 41 plants of 11 species (Alopecurus ovatus, Deschampsia alpina, Festuca rubra ssp. richardsonii, putative viviparous hybrids of Poa arctica and Poa pratensis, Poa arctica ssp. arctica, Trisetum spicatum, Coptidium spitsbergense, Ranunculus nivalis, Ranunculus pygmaeus, Ranunculus sulphureus and Taraxacum arcticum) sampled from 10 sites. Both coarse AM endophyte, with hyphae of 5-10 μm width, vesicles and occasional arbuscules, and fine endophyte, consisting of hyphae of 1-3 μm width and sparse arbuscules, were recorded in roots. Coarse AM hyphae, vesicles, arbuscules and fine endophyte hyphae occupied 1.0-30.7, 0.8-18.3, 0.7-11.9 and 0.7-12.8% of the root lengths of colonised plants, respectively. Principal component analysis indicated no associations between the abundances of AM structures in roots and edaphic factors. We conclude that the AM symbiosis is present in grass and forb roots on Spitsbergen.

  8. Genetic evidence for auxin involvement in arbuscular mycorrhiza initiation.

    Science.gov (United States)

    Hanlon, Meredith T; Coenen, Catharina

    2011-02-01

    • Formation of arbuscular mycorrhiza (AM) is controlled by a host of small, diffusible signaling molecules, including phytohormones. To test the hypothesis that the plant hormone auxin controls mycorrhiza development, we assessed mycorrhiza formation in two mutants of tomato (Solanum lycopersicum): diageotropica (dgt), an auxin-resistant mutant, and polycotyledon (pct), a mutant with hyperactive polar auxin transport. • Mutant and wild-type (WT) roots were inoculated with spores of the AM fungus Glomus intraradices. Presymbiotic root-fungus interactions were observed in root organ culture (ROC) and internal fungal colonization was quantified both in ROC and in intact seedlings. • In ROC, G. intraradices stimulated presymbiotic root branching in pct but not in dgt roots. pct roots stimulated production of hyphal fans indicative of appressorium formation and were colonized more rapidly than WT roots. By contrast, approaching hyphae reversed direction to grow away from cultured dgt roots and failed to colonize them. In intact seedlings, pct and dgt roots were colonized poorly, but development of hyphae, arbuscules, and vesicles was morphologically normal within roots of both mutants. • We conclude that auxin signaling within host roots is required for the early stages of AM formation, including during presymbiotic signal exchange. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

  9. Arbuscular, ecto-related, orchid mycorrhizas--three independent structural lineages towards mycoheterotrophy: implications for classification?

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    Imhof, Stephan

    2009-08-01

    The classification of mycorrhizas in seven equally ranked types glosses over differences and similarities and, in particular, does not acknowledge the structural diversity of arbuscular mycorrhizas. This article emphasizes the parallel continua of ecto-related mycorrhizas and arbuscular mycorrhizas, exemplified within Ericaceae and Gentianales, respectively, as well as the proprietary development of orchid mycorrhizas, all three of which have independently developed mycoheterotrophic plants. A hierarchical classification according to structural similarities is suggested.

  10. [Regulatory genes of garden pea (Pisum sativum L.) controlling the development of nitrogen-fixing nodules and arbuscular mycorrhiza: a review of basic and applied aspects

    DEFF Research Database (Denmark)

    Borisov, A Iu; Vasil'chikov, A G; Voroshilova, V A

    2007-01-01

    . Progress in identifying and cloning symbiotic genes is adequately reflected. The feasibility of using double inoculation as a means of increasing the plant productivity is demonstrated, in which the potential of a tripartite symbiotic system (pea plants-root nodule bacteria-arbuscular mycorrhiza...

  11. 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...

  12. Ecto- or arbuscular mycorrhizas ± which are best?

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    D. J. Lodge

    2000-01-01

    Few topics in ecology are as intriguing or bedeviling as comparative studies of different types of mycorrhizas formed in the same plant species. Attempts to determine the relative bene®ts from each fungal type to the host plant are fraught with difficulties (Jones et al., 1998), and for this reason plants that form tripartite associations with arbuscular and...

  13. Sulfur Transfer through an Arbuscular Mycorrhiza1

    Science.gov (United States)

    Allen, James W.; Shachar-Hill, Yair

    2009-01-01

    Despite the importance of sulfur (S) for plant nutrition, the role of the arbuscular mycorrhizal (AM) symbiosis in S uptake has received little attention. To address this issue, 35S-labeling experiments were performed on mycorrhizas of transformed carrot (Daucus carota) roots and Glomus intraradices grown monoxenically on bicompartmental petri dishes. The uptake and transfer of 35SO42− by the fungus and resulting 35S partitioning into different metabolic pools in the host roots was analyzed when altering the sulfate concentration available to roots and supplying the fungal compartment with cysteine (Cys), methionine (Met), or glutathione. Additionally, the uptake, transfer, and partitioning of 35S from the reduced S sources [35S]Cys and [35S]Met was determined. Sulfate was taken up by the fungus and transferred to mycorrhizal roots, increasing root S contents by 25% in a moderate (not growth-limiting) concentration of sulfate. High sulfate levels in the mycorrhizal root compartment halved the uptake of 35SO42− from the fungal compartment. The addition of 1 mm Met, Cys, or glutathione to the fungal compartment reduced the transfer of sulfate by 26%, 45%, and 80%, respectively, over 1 month. Similar quantities of 35S were transferred to mycorrhizal roots whether 35SO42−, [35S]Cys, or [35S]Met was supplied in the fungal compartment. Fungal transcripts for putative S assimilatory genes were identified, indicating the presence of the trans-sulfuration pathway. The suppression of fungal sulfate transfer in the presence of Cys coincided with a reduction in putative sulfate permease and not sulfate adenylyltransferase transcripts, suggesting a role for fungal transcriptional regulation in S transfer to the host. A testable model is proposed describing root S acquisition through the AM symbiosis. PMID:18978070

  14. Enhanced growth of multipurpose Calliandra (Calliandra calothyrsus) using arbuscular mycorrhiza fungi in Uganda.

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    Sebuliba, Esther; Nyeko, Phillip; Majaliwa, Mwanjalolo; Eilu, Gerald; Kizza, Charles Luswata; Ekwamu, Adipala

    2012-01-01

    This study was conducted to compare the effect of selected arbuscular mycorrhiza fungi genera and their application rates for enhanced Calliandra growth in Uganda. The performance of Calliandra under different types and rates of arbuscular mycorrhiza fungi inoculation was assessed in the greenhouse using sterilized Mabira soils. Four dominant genera were isolated from the rhizosphere of sorghum in the laboratory. Calliandra seeds were grown in pots and the seed coating method of application was used at concentrations of 0 spores, 30 spores and 50 spores. Each treatment was replicated three times. All Calliandra inoculated seedlings showed improved seedling growth (in terms of height and shoot dry matter weight) compared to the control (P arbuscular mycorrhiza fungi mixture treated Calliandra at 50 spores rate. Glomus sp. and Acaulospora sp. had significant influence on the height of Calliandra, while AMF mixture performed best in terms of shoot dry weight (P arbuscular mycorrhiza fungi for beneficial effects in the primary establishment of slow growing seedlings ensuring better survival and improved growth.

  15. Enhanced Growth of Multipurpose Calliandra (Calliandra calothyrsus) Using Arbuscular Mycorrhiza Fungi in Uganda

    Science.gov (United States)

    Sebuliba, Esther; Nyeko, Phillip; Majaliwa, Mwanjalolo; Eilu, Gerald; Kizza, Charles Luswata; Ekwamu, Adipala

    2012-01-01

    This study was conducted to compare the effect of selected arbuscular mycorrhiza fungi genera and their application rates for enhanced Calliandra growth in Uganda. The performance of Calliandra under different types and rates of arbuscular mycorrhiza fungi inoculation was assessed in the greenhouse using sterilized Mabira soils. Four dominant genera were isolated from the rhizosphere of sorghum in the laboratory. Calliandra seeds were grown in pots and the seed coating method of application was used at concentrations of 0 spores, 30 spores and 50 spores. Each treatment was replicated three times. All Calliandra inoculated seedlings showed improved seedling growth (in terms of height and shoot dry matter weight) compared to the control (P < 0.05) except with the arbuscular mycorrhiza fungi mixture treated Calliandra at 50 spores rate. Glomus sp. and Acaulospora sp. had significant influence on the height of Calliandra, while AMF mixture performed best in terms of shoot dry weight (P < 0.05). This study provides a good scope for commercially utilizing the efficient strains of arbuscular mycorrhiza fungi for beneficial effects in the primary establishment of slow growing seedlings ensuring better survival and improved growth. PMID:23365530

  16. Enhanced Growth of Multipurpose Calliandra (Calliandra calothyrsus Using Arbuscular Mycorrhiza Fungi in Uganda

    Directory of Open Access Journals (Sweden)

    Esther Sebuliba

    2012-01-01

    Full Text Available This study was conducted to compare the effect of selected arbuscular mycorrhiza fungi genera and their application rates for enhanced Calliandra growth in Uganda. The performance of Calliandra under different types and rates of arbuscular mycorrhiza fungi inoculation was assessed in the greenhouse using sterilized Mabira soils. Four dominant genera were isolated from the rhizosphere of sorghum in the laboratory. Calliandra seeds were grown in pots and the seed coating method of application was used at concentrations of 0 spores, 30 spores and 50 spores. Each treatment was replicated three times. All Calliandra inoculated seedlings showed improved seedling growth (in terms of height and shoot dry matter weight compared to the control (P<0.05 except with the arbuscular mycorrhiza fungi mixture treated Calliandra at 50 spores rate. Glomus sp. and Acaulospora sp. had significant influence on the height of Calliandra, while AMF mixture performed best in terms of shoot dry weight (P<0.05. This study provides a good scope for commercially utilizing the efficient strains of arbuscular mycorrhiza fungi for beneficial effects in the primary establishment of slow growing seedlings ensuring better survival and improved growth.

  17. Arbuscular mycorrhizas reduce nitrogen loss via leaching.

    Directory of Open Access Journals (Sweden)

    Hamid R Asghari

    Full Text Available The capacity of mycorrhizal and non-mycorrhizal root systems to reduce nitrate (NO₃⁻ and ammonium (NH₄⁺ loss from soils via leaching was investigated in a microcosm-based study. A mycorrhiza defective tomato mutant and its mycorrhizal wildtype progenitor were used in this experiment in order to avoid the indirect effects of establishing non-mycorrhizal control treatments on soil nitrogen cycling and the wider soil biota. Mycorrhizal root systems dramatically reduced nitrate loss (almost 40 times less via leaching, compared to their non-mycorrhizal counterparts, following a pulse application of ammonium nitrate to experimental microcosms. The capacity of AM to reduce nutrient loss via leaching has received relatively little attention, but as demonstrated here, can be significant. Taken together, these data highlight the need to consider the potential benefits of AM beyond improvements in plant nutrition alone.

  18. Arbuscular mycorrhizas reduce nitrogen loss via leaching.

    Science.gov (United States)

    Asghari, Hamid R; Cavagnaro, Timothy R

    2012-01-01

    The capacity of mycorrhizal and non-mycorrhizal root systems to reduce nitrate (NO₃⁻) and ammonium (NH₄⁺) loss from soils via leaching was investigated in a microcosm-based study. A mycorrhiza defective tomato mutant and its mycorrhizal wildtype progenitor were used in this experiment in order to avoid the indirect effects of establishing non-mycorrhizal control treatments on soil nitrogen cycling and the wider soil biota. Mycorrhizal root systems dramatically reduced nitrate loss (almost 40 times less) via leaching, compared to their non-mycorrhizal counterparts, following a pulse application of ammonium nitrate to experimental microcosms. The capacity of AM to reduce nutrient loss via leaching has received relatively little attention, but as demonstrated here, can be significant. Taken together, these data highlight the need to consider the potential benefits of AM beyond improvements in plant nutrition alone.

  19. Arbuscular mycorrhiza in soil quality assessment

    DEFF Research Database (Denmark)

    Kling, M.; Jakobsen, I.

    1998-01-01

    aggregates and to the protection of plants against drought and root pathogens. Assessment of soil quality, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant health, should therefore include both...... quantitative and qualitative measurements of this important biological resource. Various methods for the assessment of the potential for mycorrhiza formation and function are presented. Examples are given of the application of these methods to assess the impact of pesticides on the mycorrhiza....

  20. [Arbuscular mycorrhiza of cultivated and wild Pinellia ternata].

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    Cheng, Litao; Guo, Qiaosheng; Liu, Zuoyi

    2010-02-01

    To study the arbuscular mycorrhiza and arbuscular mycorrhizal fungi associated with cultivated and wild Pinellia ternata in Guizhou province. Wild and cultivated P. ternata roots were observed through staining and microscopic examination, the arbuscular mycorrhizal fungi spores were isolated through wet thieving according to Gerdemann & Nicolson (1963), the spores were identified following the description of Schenck & Pérez (1988), and some previous publications. The typical arbuscular mycorrhiza (AM) structure was showed according to a research of wild and cultivated P. ternata. In the survey of AM fungi species in the rhizosphere of wild and cultivated P. ternata, 3 genera and 21 species were found, 3 genera and 7 species were identified. 5 species of them belong to Glomus, 1 species belongs to Scutellospora, 1 species belongs to Gigaspora, including Glomus mosseae, G. intraradices, G. melanosporum, G. deserticola, G. aggregatum, Scutellospora castanea, Gigaspora albida, and one of them was a new record, i.e., Scutellospora castanea which was the dominant species in Bijie. The diversity of AM fungi between wild and cultivated Pinellia ternata was showed on this survey, the fungi associated with wild ones are different form the cultivated ones, such as Gigaspora albida only occurs in cultivated ones, Glomus melanosporum only occurs in wild ones, while Glomus mosseae and Glomus intraradices occur in both wild and cultivated ones, and there were specialization species in Bijie, all these can provide new though for solving degradation problem of cultivated Pinellia ternata.

  1. Plant nutrient transporter regulation in arbuscular mycorrhizas

    DEFF Research Database (Denmark)

    Burleigh, Stephen; Bechmann, I.E.

    2002-01-01

    This review discusses the role arbuscular mycorrhizal fungi play in the regulation of plant nutrient transporter genes. Many plant nutrient transporter genes appear to be transcriptionally regulated by a feed-back mechanism that reduces their expression when the plant reaches an optimal level...

  2. [Ecological significance of arbuscular mycorrhiza biotechnology in modern agricultural system].

    Science.gov (United States)

    Zhang, Yong; Zeng, Ming; Xiong, Bingquan; Yang, Xiaohong

    2003-04-01

    Mycorrhiza plays a key role in nutrient cycling in ecosystem, and protects host plant against environmental stress. Under natural condition, plant's mycorrhizal structure is a normal phenomenon, and arbuscular mycorrhiza (AM) association is the commonest mycorrhizal type. If well mycorrhizal structure can be formed during plant root system developing process, the quantity and quality of plant production will be improved in large. Because of its effects on plant growth and health, it is accepted that AM symbiosis can reduce chemical fertilizer and pesticide inputs. Consequently, this will lead to a reduction in harmful chemical substance impact on environment. The key effects of AM symbiosis can be summarized as follows: (1) improving rooting and plant establishment; (2) improving uptake of low mobile ions; (3) improving nutrient cycling; (4) enhancing plant tolerance to (biotic and abiotic) stress; (5) improving quality of soil structure; and (6) enhancing plant community diversity. In this paper, the ecological characteristic of arbuscular mycorrhiza fungi (AMF), effects of AM on host plant, and ecologic significance of AM biotechnology in agricultural system were reviewed.

  3. Cell and developmental biology of arbuscular mycorrhiza symbiosis.

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    Gutjahr, Caroline; Parniske, Martin

    2013-01-01

    The default mineral nutrient acquisition strategy of land plants is the symbiosis with arbuscular mycorrhiza (AM) fungi. Research into the cell and developmental biology of AM revealed fascinating insights into the plasticity of plant cell development and of interorganismic communication. It is driven by the prospect of increased exploitation of AM benefits for sustainable agriculture. The plant cell developmental program for intracellular accommodation of AM fungi is activated by a genetically defined signaling pathway involving calcium spiking in the nucleus as second messenger. Calcium spiking is triggered by chitooligosaccharides released by AM fungi that are probably perceived via LysM domain receptor kinases. Fungal infection and calcium spiking are spatiotemporally coordinated, and only cells committed to accommodating the fungus undergo high-frequency spiking. Delivery of mineral nutrients by AM fungi occurs at tree-shaped hyphal structures, the arbuscules, in plant cortical cells. Nutrients are taken up at a plant-derived periarbuscular membrane, which surrounds fungal hyphae and carries a specific transporter composition that is of direct importance for symbiotic efficiency. An elegant study has unveiled a new and unexpected mechanism for specific protein localization to the periarbuscular membrane, which relies on the timing of gene expression to synchronize protein biosynthesis with a redirection of secretion. The control of AM development by phytohormones is currently subject to active investigation and has led to the rediscovery of strigolactones. Nearly all tested phytohormones regulate AM development, and major insights into the mechanisms of this regulation are expected in the near future.

  4. Apoplastic plant subtilases support arbuscular mycorrhiza development in Lotus japonicus.

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    Takeda, Naoya; Sato, Shusei; Asamizu, Erika; Tabata, Satoshi; Parniske, Martin

    2009-06-01

    In the arbuscular mycorrhiza (AM) symbiosis, plant roots accommodate Glomeromycota fungi within an intracellular compartment, the arbuscule. At this symbiotic interface, fungal hyphae are surrounded by a plant membrane, which creates an apoplastic compartment, the periarbuscular space (PAS) between fungal and plant cell. Despite the importance of the PAS for symbiotic signal and metabolite exchange, only few of its components have been identified. Here we show that two apoplastic plant proteases of the subtilase family are required for AM development. SbtM1 is the founder member of a family of arbuscular mycorrhiza-induced subtilase genes that occur in at least two clusters in the genome of the legume Lotus japonicus. A detailed expression analysis by RT-PCR revealed that SbtM1, SbtM3, SbtM4 and the more distantly related SbtS are all rapidly induced during development of arbuscular mycorrhiza, but only SbtS and SbtM4 are also up-regulated during root nodule symbiosis. Promoter-reporter fusions indicated specific activation in cells that are adjacent to intra-radical fungal hyphae or in cells that harbour them. Venus fluorescent protein was observed in the apoplast and the PAS when expressed from a fusion construct with the SbtM1 signal peptide or the full-length subtilase. Suppression of SbtM1 or SbtM3 by RNAi caused a decrease in intra-radical hyphae and arbuscule colonization, but had no effect on nodule formation. Our data indicate a role for these subtilases during the fungal infection process in particular arbuscule development.

  5. Arbuscular mycorrhiza in soil quality assessment

    DEFF Research Database (Denmark)

    Kling, M.; Jakobsen, I.

    1998-01-01

    Arbuscular mycorrhizal (AM) fungi constitute a living bridge for the transport of nutrients from soil to plant roots, and are considered as the group of soil microorganisms that is of most direct importance to nutrient uptake by herbaceous plants. AM fungi also contribute to the formation of soil...... aggregates and to the protection of plants against drought and root pathogens. Assessment of soil quality, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality, and promote plant health, should therefore include both...

  6. Auxins as Signals in Arbuscular Mycorrhiza Formation

    Science.gov (United States)

    Güther, Mike

    2007-01-01

    Plant hormones such as auxin derivatives are likely signals during the establishment of an arbuscular mycorrhizal (AM) symbiosis. Although reports on auxin levels during AM in different plant species are contradictory, the contribution of auxins to the establishment of an AM symbiosis might be an important factor especially for the development of lateral roots which are the preferred infection sites for the fungi. In addition to evidence that different auxins could be elevated after colonization with AM fungi, there are also overlapping gene expression patterns between auxin-treated and AM-inoculated roots that provide further clues on auxin-triggered colonization events. Using an auxin-inducible promoter-reporter system it was shown that the reporter was strongly induced in AM colonized roots, although co-localization with AM fungi was not observed. Our data are discussed in frame of a model together with other plant hormones which might be involved in the AM colonization processes. PMID:19704695

  7. Environment and Host Affects Arbuscular Mycorrhiza Fungi (AMF) Population.

    Science.gov (United States)

    Rahim, Norahizah Abd; Jais, Hasnah Md; Hassan, Hasnuri Mat

    2016-11-01

    The association of arbuscular mycorrhiza fungi (AMF) and roots undoubtedly gives positive advantages to the host plant. However, heavily fertilised soil such as in oil palm plantation, inhibit the growth of mycorrhiza. Thus, the aim of this research is to distinguish and quantify the availability of AMF population and propagules at different sites of an oil palm plantation by Most Probable Number (MPN) assay. In addition, root infection method was employed to observe host compatibility through the propagation of AMF using two different types of hosts, monocotyledon (Echinochloa cruss-galli) and dicotyledon (Vigna radiata). Three different locations at an oil palm plantation were chosen for sampling. Each location was represented by a distinctive soil series, and were further divided into two sites, that is canopy and midway area. Midway site had a greater population of AMF compared to canopy. The result showed that different environments affect the availability of AMF in the soil. Higher number of AMF infection observed in monocotyledon host suggests that the fibrous root system provide a better association with mycorrhiza.

  8. Environment and Host Affects Arbuscular Mycorrhiza Fungi (AMF) Population

    Science.gov (United States)

    Rahim, Norahizah Abd; Jais, Hasnah Md; Hassan, Hasnuri Mat

    2016-01-01

    The association of arbuscular mycorrhiza fungi (AMF) and roots undoubtedly gives positive advantages to the host plant. However, heavily fertilised soil such as in oil palm plantation, inhibit the growth of mycorrhiza. Thus, the aim of this research is to distinguish and quantify the availability of AMF population and propagules at different sites of an oil palm plantation by Most Probable Number (MPN) assay. In addition, root infection method was employed to observe host compatibility through the propagation of AMF using two different types of hosts, monocotyledon (Echinochloa cruss-galli) and dicotyledon (Vigna radiata). Three different locations at an oil palm plantation were chosen for sampling. Each location was represented by a distinctive soil series, and were further divided into two sites, that is canopy and midway area. Midway site had a greater population of AMF compared to canopy. The result showed that different environments affect the availability of AMF in the soil. Higher number of AMF infection observed in monocotyledon host suggests that the fibrous root system provide a better association with mycorrhiza. PMID:27965735

  9. Unraveling the signaling and signal transduction mechanisms controlling arbuscular mycorrhiza development Desenredando os mecanismo de sinalização e transdução de sinais que controlam o desenvolvimento de micorrizas arbusculares

    Directory of Open Access Journals (Sweden)

    Marcio Rodrigues Lambais

    2006-08-01

    Full Text Available Arbuscular mycorrhiza (AM are the most widespread symbiotic associations between plant roots and soil fungi. AM can contribute to increasing the survival and fitness of plants to limiting environments mostly due to their ability in improving nutrient uptake from the soil solution. Despite their ecological significance, the mechanisms controlling AM development and functioning are largely unknown. The obligate mutualistic nature of the arbuscular mycorrhizal fungi (AMF has hampered the advances on the understanding and application of the symbiosis. Significant alterations in the genetic programs of both symbionts are required for the successful establishment of an AM, and complex signaling and signal transduction mechanisms are likely involved. The analyses of legume mutants affected in the development of nitrogen fixing nodules and AM suggest that part of the signal transduction pathways involved in the regulation of both symbioses are conserved. Even though the use of genomics of model plants has helped to advance our understanding of the regulatory mechanisms in AM, identifying the signal molecules involved in plant-AMF communication and determining their transduction pathways is still essential for its biotechnological application in agriculture.As micorrizas arbusculares (MAs são as associações simbióticas entre raízes de plantas e fungos mais comuns na natureza. Elas podem contribuir para o aumento da sobrevivência e adaptação das plantas a ambientes limitantes, principalmente devido a sua maior capacidade em absorver nutrientes da solução do solo. Apesar de sua importância ecológica, os mecanismos que controlam o desenvolvimento e fisiologia das MAs são pouco conhecidos. A natureza mutualística obrigatória dos fungos micorrízicos arbusculares (FMAs tem limitado os avanços na compreensão e aplicação da simbiose. Alterações significativas nos programas genéticos de ambos simbiontes são necessárias para o

  10. Successful joint ventures of plants: arbuscular mycorrhiza and beyond.

    Science.gov (United States)

    Ercolin, Flavia; Reinhardt, Didier

    2011-07-01

    Among the oldest symbiotic associations of plants are arbuscular mycorrhiza (AM) with fungi of the phylum Glomeromycota. Although many of the symbiotic signaling components have been identified on the side of the plant, AM fungi have long evaded genetic analysis owing to their strict biotrophy and their exceptional genetics. Recently, the identification of the fungal symbiosis signal (Myc factor) and of a corresponding Myc factor receptor, and new insights into AM fungal genetics, have opened new avenues to address early communication and functional aspects of AM symbiosis. These advances will pave the way for breeding programs towards adapted AM fungi for crop production, and will shed light on the ecology and evolution of this remarkably successful symbiosis. Copyright © 2011. Published by Elsevier Ltd.

  11. The role of arbuscular mycorrhizas in reducing soil nutrient loss.

    Science.gov (United States)

    Cavagnaro, Timothy R; Bender, S Franz; Asghari, Hamid R; Heijden, Marcel G A van der

    2015-05-01

    Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    In this Update, we review new findings about the roles of the arbuscular mycorrhizas (mycorrhiza = fungus plus root) in plant growth and phosphorus (P) nutrition. We focus particularly on the function of arbuscular mycorrhizal (AM) symbioses with different outcomes for plant growth (from positive...

  13. Arbuscular mycorrhiza effects on plant performance under osmotic stress.

    Science.gov (United States)

    Santander, Christian; Aroca, Ricardo; Ruiz-Lozano, Juan Manuel; Olave, Jorge; Cartes, Paula; Borie, Fernando; Cornejo, Pablo

    2017-06-25

    At present, drought and soil salinity are among the most severe environmental stresses that affect the growth of plants through marked reduction of water uptake which lowers water potential, leading to osmotic stress. In general, osmotic stress causes a series of morphological, physiological, biochemical, and molecular changes that affect plant performance. Several studies have found that diverse types of soil microorganisms improve plant growth, especially when plants are under stressful conditions. Most important are the arbuscular mycorrhizal fungi (AMF) which form arbuscular mycorrhizas (AM) with approximately 80% of plant species and are present in almost all terrestrial ecosystems. Beyond the well-known role of AM in improving plant nutrient uptake, the contributions of AM to plants coping with osmotic stress merit analysis. With this review, we describe the principal direct and indirect mechanisms by which AM modify plant responses to osmotic stress, highlighting the role of AM in photosynthetic activity, water use efficiency, osmoprotectant production, antioxidant activities, and gene expression. We also discuss the potential for using AMF to improve plant performance under osmotic stress conditions and the lines of research needed to optimize AM use in plant production.

  14. Regulação do desenvolvimento de micorrizas arbusculares Regulation of arbuscular mycorrhizae development

    Directory of Open Access Journals (Sweden)

    Soraya Gabriela Kiriachek

    2009-02-01

    Full Text Available As micorrizas arbusculares (MAs são associações simbióticas mutualistas entre fungos do filo Glomeromycota e a maioria das plantas terrestres. A formação e o funcionamento das MAs depende de um complexo processo de troca de sinais, que resulta em mudanças no metabolismo dos simbiontes e na diferenciação de uma interface simbiótica no interior das células das raízes. Os mecanismos que regulam a formação das MAs são pouco conhecidos, mas sabe-se que a concentração de fosfato (P na planta é um fator determinante para o desenvolvimento da simbiose. A disponibilidade de P na planta pode afetar o balanço de açúcares e de fitormônios (FHs, além da expressão de genes de defesa vegetal. Com o advento da genômica e proteômica, vários genes essenciais para o desenvolvimento das MAs já foram identificados e seus mecanismos de regulação estão sendo estudados. Até o presente, sabe-se que as plantas secretam substâncias que estimulam a germinação de esporos e o crescimento de fungos micorrízicos arbusculares (FMAs. Há evidências também de que os FMAs sintetizam moléculas sinalizadoras, que são reconhecidas pelas plantas hospedeiras. Pelo menos três genes são essenciais para o reconhecimento dessa molécula e a transdução do sinal molecular. Discutem-se os papéis desses genes e os possíveis mecanismos que regulam sua expressão, bem como os papéis dos FHs na regulação de MAs são discutidos.Arbuscular mycorrhizae (AM are mutualistic symbiotic associations between fungi of the phylum Glomeromycota and most terrestrial plants. The formation and functioning of AM depend on a complex signal exchange process, which ultimately results in shifts in the metabolism of the symbionts and differentiation of a symbiotic interface in cortical root cells. The mechanisms regulating AM development are not well understood, but it is known that phosphate (P concentration in plants plays a key role in this process. Plant P

  15. Arbuscular mycorrhiza reduces susceptibility of tomato to Alternaria solani.

    Science.gov (United States)

    Fritz, Maendy; Jakobsen, Iver; Lyngkjaer, Michael Foged; Thordal-Christensen, Hans; Pons-Kühnemann, Jörn

    2006-09-01

    Mycorrhiza frequently leads to the control of root pathogens, but appears to have the opposite effect on leaf pathogens. In this study, we studied mycorrhizal effects on the development of early blight in tomato (Solanum lycopersicum) caused by the necrotrophic fungus Alternaria solani. Alternaria-induced necrosis and chlorosis of all leaves were studied in mycorrhizal and non-mycorrhizal plants over time course and at different soil P levels. Mycorrhizal tomato plants had significantly less A. solani symptoms than non-mycorrhizal plants, but neither plant growth nor phosphate uptake was enhanced by mycorrhizas. An increased P supply had no effect on disease severity in non-mycorrhizal plants, but led to a higher disease severity in mycorrhizal plants. This was parallel to a P-supply-induced reduction in mycorrhiza formation. The protective effect of mycorrhizas towards development of A. solani has some parallels to induced systemic resistance, mediated by rhizobacteria: both biocontrol agents are root-associated organisms and both are effective against necrotrophic pathogens. The possible mechanisms involved are discussed.

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

    Science.gov (United States)

    Wróbel-Kwiatkowska, Magdalena; Turnau, Katarzyna; Góralska, Katarzyna; Anielska, Teresa; Szopa, Jan

    2012-10-01

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

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

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    Ewa Gucwa-Przepióra

    2011-01-01

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

  18. Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

    DEFF Research Database (Denmark)

    Roos, Per; Jakobsen, Iver

    2008-01-01

    Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non......-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock. (c) 2007 Elsevier Ltd. All rights......-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant...

  19. Arbuscular mycorrhiza reduces phytoextraction of uranium, thorium and other elements from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Roos, Per [Radiation Research Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Jakobsen, Iver [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark)], E-mail: iver.jakobsen@risoe.dk

    2008-05-15

    Uptake of metals from uranium-rich phosphate rock was studied in Medicago truncatula plants grown in symbiosis with the arbuscular mycorrhizal fungus Glomus intraradices or in the absence of mycorrhizas. Shoot concentrations of uranium and thorium were lower in mycorrhizal than in non-mycorrhizal plants and root-to-shoot ratio of most metals was increased by mycorrhizas. This protective role of mycorrhizas was observed even at very high supplies of phosphate rock. In contrast, phosphorus uptake was similar at all levels of phosphate rock, suggesting that the P was unavailable to the plant-fungus uptake systems. The results support the role of arbuscular mycorrhiza as being an important component in phytostabilization of uranium. This is the first study to report on mycorrhizal effect and the uptake and root-to-shoot transfer of thorium from phosphate rock.

  20. [Structure and function of arbuscular mycorrhiza: a review].

    Science.gov (United States)

    Tian, Mi; Chen, Ying-long; Li, Min; Liu, Run-jin

    2013-08-01

    Arbuscular mycorrhiza (AM) is one of the most widely distributed and the most important mutualistic symbionts in terrestrial ecosystems, playing a significant role in enhancing plant resistance to stresses, remediating polluted environments, and maintaining ecosystem stabilization and sustainable productivity. The structural characteristics of AM are the main indicators determining the mycorrhizal formation in root system, and have close relations to the mycorrhizal functions. This paper summarized the structural characteristics of arbuscules, vesicles, mycelia and invasion points of AM, and analyzed the relationships between the Arum (A) type arbuscules, Paris (P) type arbuscules, vesicles, and external mycelia and their functions in improving plant nutrient acquisition and growth, enhancing plant resistance to drought, waterlogging, salinity, high temperature, diseases, heavy metals toxicity, and promoting toxic organic substances decomposition and polluted and degraded soil remediation. The factors affecting the AM structure and functions as well as the action mechanisms of mycorrhizal functions were also discussed. This review would provide a basis for the systemic study of AM structural characteristics and functional mechanisms and for evaluating and screening efficient AM fungal species.

  1. Arbuscular mycorrhiza: the mother of plant root endosymbioses.

    Science.gov (United States)

    Parniske, Martin

    2008-10-01

    Arbuscular mycorrhiza (AM), a symbiosis between plants and members of an ancient phylum of fungi, the Glomeromycota, improves the supply of water and nutrients, such as phosphate and nitrogen, to the host plant. In return, up to 20% of plant-fixed carbon is transferred to the fungus. Nutrient transport occurs through symbiotic structures inside plant root cells known as arbuscules. AM development is accompanied by an exchange of signalling molecules between the symbionts. A novel class of plant hormones known as strigolactones are exuded by the plant roots. On the one hand, strigolactones stimulate fungal metabolism and branching. On the other hand, they also trigger seed germination of parasitic plants. Fungi release signalling molecules, in the form of 'Myc factors' that trigger symbiotic root responses. Plant genes required for AM development have been characterized. During evolution, the genetic programme for AM has been recruited for other plant root symbioses: functional adaptation of a plant receptor kinase that is essential for AM symbiosis paved the way for nitrogen-fixing bacteria to form intracellular symbioses with plant cells.

  2. Lipid transfer from plants to arbuscular mycorrhiza fungi

    Science.gov (United States)

    Keymer, Andreas; Pimprikar, Priya; Wewer, Vera; Huber, Claudia; Brands, Mathias; Bucerius, Simone L; Delaux, Pierre-Marc; Klingl, Verena; von Röpenack-Lahaye, Edda; Wang, Trevor L; Eisenreich, Wolfgang; Dörmann, Peter; Parniske, Martin; Gutjahr, Caroline

    2017-01-01

    Arbuscular mycorrhiza (AM) symbioses contribute to global carbon cycles as plant hosts divert up to 20% of photosynthate to the obligate biotrophic fungi. Previous studies suggested carbohydrates as the only form of carbon transferred to the fungi. However, de novo fatty acid (FA) synthesis has not been observed in AM fungi in absence of the plant. In a forward genetic approach, we identified two Lotus japonicus mutants defective in AM-specific paralogs of lipid biosynthesis genes (KASI and GPAT6). These mutants perturb fungal development and accumulation of emblematic fungal 16:1ω5 FAs. Using isotopolog profiling we demonstrate that 13C patterns of fungal FAs recapitulate those of wild-type hosts, indicating cross-kingdom lipid transfer from plants to fungi. This transfer of labelled FAs was not observed for the AM-specific lipid biosynthesis mutants. Thus, growth and development of beneficial AM fungi is not only fueled by sugars but depends on lipid transfer from plant hosts. DOI: http://dx.doi.org/10.7554/eLife.29107.001 PMID:28726631

  3. Isolation and Identification of Vesicular-Arbuscular Mycorrhiza-Stimulatory Compounds from Clover (Trifolium repens) Roots

    Science.gov (United States)

    Nair, Muraleedharan G.; Safir, Gene R.; Siqueira, Jose O.

    1991-01-01

    Two isoflavonoids isolated from clover roots grown under phosphate stress were characterized as formononetin (7-hydroxy,4′-methoxy isoflavone) and biochanin A (5,7-dihydroxy,4′-methoxy isoflavone). At 5 ppm, these compounds stimulated hyphal growth in vitro and root colonization of an undescribed vesicular-arbuscular mycorrhiza, a Glomus sp. (INVAM-112). The permethylated products of the two compounds were inactive. These findings suggest that the isoflavonoids studied may act as signal molecules in vesicular-arbuscular mycorrhiza symbiosis. PMID:16348409

  4. [Influence of elevated atmospheric CO2 on rhizosphere microbes and arbuscular mycorrhizae].

    Science.gov (United States)

    Chen, Jing; Chen, Xin; Tang, Jianjun

    2004-12-01

    The changes of microbial communities in rhizosphere and the formation of mycorrhizae play an important role in affecting the dynamics of plant communities and terrestrial ecosystems. This paper summarized and discussed the effects of elevated atmospheric CO2 on them. Under elevated atmospheric CO2, the carbohydrates accumulated in root systems increased, and the rhizospheric environment and its microbial communities as well as the formation of mycorrhizae changed. It is suggested that the researches in the future should be focused on the effects of rhizosphere microbes and arbuscular mycorrhizae on regulating the carbon dynamics of plant communities and terrestrial ecosystems under elevated atmospheric CO2.

  5. Arbuscular mycorrhizae enhance metal lead uptake and growth of host plants under a sand culture experiment.

    Science.gov (United States)

    Chen, Xin; Wu, Chunhua; Tang, Jianjun; Hu, Shuijin

    2005-07-01

    A sand culture experiment was conducted to investigate whether mycorrhizal colonization and mycorrhizal fungal vesicular numbers were influenced by metal lead, and whether mycorrhizae enhance host plants tolerance to metal lead. Metal lead was applied as Pb(NO3)2 in solution at three levels (0, 300 and 600 mg kg(-1) sand). Five mycorrhizal host plant species, Kummerowia striata (Thunb.) Schindl, Ixeris denticulate L., Lolium perenne L., Trifolium repens L. and Echinochloa crusgalli var. mitis were used to examine Pb-mycorrhizal interactions. The arbuscular mycorrhizal inoculum consisted of mixed spores of mycorrhizal fungal species directly isolated from orchard soil. Compared to the untreated control, both Pb concentrations reduced mycorrhizal colonization by 3.8-70.4%. Numbers of AM fungal vesicles increased by 13.2-51.5% in 300 mg Pb kg(-1) sand but decreased by 9.4-50.9% in 600 mg Pb kg(-1) sand. Mycorrhizae significantly enhanced Pb accumulation both in shoot by 10.2-85.5% and in root by 9.3-118.4%. Mycorrhizae also enhanced shoot biomass and shoot P concentration under both Pb concentrations. Root/shoot ratios of Pb concentration were higher in highly mycorrhizal plant species (K.striata, I. denticulate, and E. crusgalli var. mitis) than that in poorly mycorrhizal ones (L. perenne and T. repens,). Mycorrhizal inoculation increased the root/shoot ratio of Pb concentration of highly mycorrhizal plant species by 7.6-57.2% but did not affect the poorly mycorrhizal ones. In the treatments with 300 Pb mg kg(-1) sand, plant species with higher vesicular numbers tended to show higher root/shoot ratios of the Pb concentration. We suggest that under an elevated Pb condition, mycorrhizae could promote plant growth by increasing P uptake and mitigate Pb toxicity by sequestrating more Pb in roots.

  6. Effect of Arbuscular Mycorrhiza Fungi Inoculation on Growth and Up take of Mineral Nutrition in Ipomoea Aquatica.

    Directory of Open Access Journals (Sweden)

    Milton Halder

    2015-04-01

    Full Text Available A green house experiment was conducted to investigate the effect of arbuscular mycorrhiza inoculation on plant growth and uptake of mineral nutrition in Ipomoea aquatica considering the objective of using environmental friendly biofertilizer instead of chemical fertilizer. A common leafy vegetable plant Ipomoea aquatica was grown with mycorrhiza and without mycorrhiza for 42 days. After harvest the plants were analyzed for mineral nutrition concentration. Plant fresh weight, dry weight, macronutrient (P, K, Mg, Na, micronutrient (Fe, Mn, Zn concentration was higher in arbuscular mycorrhiza inoculated plant than non-mycorrhiza inoculated plant. For sustainable agriculture, introducing biofertilizer by using arbuscular mycorrhiza inoculation would be one of the most efficient techniques for replacing chemical fertilizer to meet the nutrient deficiency in nutrient deficient soils of Bangladesh.

  7. Investigation of dryland wheat (Triticum aestivum L. cv. Azar 2 plants response to symbiosis with arbuscular mycorrhiza and mycorrhiza like fungi under different levels of drought stress

    Directory of Open Access Journals (Sweden)

    Y. Yaghoubian

    2016-05-01

    Full Text Available In order to evaluate arbuscular mycorrhiza (Glomuss mossea and mycorrhiza-like (Piriformospora indica effects on yield, yield components and some morphological (cv. Azar 2 traits of wheat (Triticum aestivum L. under water deficit stress, a pot experiment was conducted as factorial experiment based on completely randomized design with four replications. Treatments were drought stress at three levels (FC, -5 and -10 bar and fungi inoculation at four levels (mycorrhiza (AM, mycorrhiza-like (MLF and co-inoculation of AM+MLF and control. Results showed that the water stress significantly decreased 1000-grain weight, spike harvest index, fertility percent of spike, plant height, peduncle and extrusion length and colonization percent while grain density per spike markedly increased. Fungi inoculation significantly improved all studied traits except harvest index, 1000-grain weight and root colonization. Co-inoculation of AM and MLF had the best performance in terms of all mentioned parameters. Interaction effects of fungi and water stress was significant on grain and biological yield, spike and grain number and positively affected by fungi inoculation. Among fungi treatments, however, co-inoculation of AM+MLF had the best performance and recommended for both stress and non stress conditions.

  8. Enzymatic evidence for the key role of arginine in nitrogen translocation by arbuscular mycorrhiza fungi

    DEFF Research Database (Denmark)

    Cruz, C.; Egsgaard, Helge; Trujillo, C.

    2007-01-01

    Key enzymes of the urea cycle and N-15-labeling patterns of arginine (Arg) were measured to elucidate the involvement of Arg in nitrogen translocation by arbuscular mycorrhizal (AM) fungi. Mycorrhiza was established between transformed carrot (Daucus carota) roots and Glomus intraradices in two...

  9. 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

  10. 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

  11. Biochemical contents of pepper seedlings inoculated with phytophthora infestans and arbuscular mycorrhiza

    Directory of Open Access Journals (Sweden)

    Odebode A.C.

    2004-01-01

    Full Text Available The effect of interactions between Arbuscular Glomus etunicatum and fungus Phytophthora infestans on biochemical contents of pepper plants was investigated in a greenhouse experiment. The sugar contents (i.e. Glucose fructose and sucrose were higher in the control and mycorrhizal inoculated pepper seedlings and the lowest in pathogen inoculated seedlings. Free amino acids were the highest in the simultaneously inoculated pepper seedlings while total phenol was found to be the highest in pepper seedlings inoculated with P. infestans. The levels of nitrogen, phosphorus and potassium varied in the inoculated pepper seedlings without any significant difference in the treatment. The results obtained suggest protective influence of mycorrhiza by enhancing the nutritional status of the inoculated pepper seedlings.

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

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colon

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

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colon

  14. Combined effects of arbuscular mycorrhizas and light on water uptake of the neotropical understory shrubs, Piper and Psychotria

    Science.gov (United States)

    Damond A. Kyllo; Virginia Velez; Melvin T. Tyree

    2003-01-01

    Root hydraulic conductance (Kr) was measured for five understory shrub species of the neotropical moist forest to determine the effects of arbuscular mycorrhizas (AM) for both carbon-rich and carbon-limited host plants.

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

    NARCIS (Netherlands)

    Gucwa-Przepióra, E.; Malkowski, E.; Sas-Nowosielska, A.; Kucharski, R.; Krzyzak, J.; Kita, A.; Römkens, P.F.A.M.

    2007-01-01

    The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex

  16. Effects of Arbuscular Mycorrhiza Fungi on Growth Characteristics of Dactylis glomerata L. under Drought Stress Conditions

    Directory of Open Access Journals (Sweden)

    Apostolos P. KYRIAZOPOULOS

    2014-06-01

    Full Text Available Limited information is available regarding the selection of effective mycorrhizae and the exploitation of their beneficial effects on the enhancement of the forage production of Dactylis glomerata under the predicted warmer and drier conditions in the Mediterranean region. The objective of this study was to test the effects of Glomus intraradices, Glomus mosseae and their mix inoculation on growth characteristics and dry matter production of Dactylis glomerata in relation to full and limited irrigation. The experiment was conducted in Orestiada, Northeastern Greece. Limited irrigation significantly decreased yield and yield components of Dactylis glomerataover the full irrigation. Drought stressed plants had significantly higher root dry weight as a response for better survival under water deficit conditions. The Arbuscular mycorrhizal fungi (AMF inoculated plants had significant higher shoot dry weight, tiller height and number of leaves in comparison to the non-inoculated plants. On the contrary, under drought stress conditions all AMF plants had lower root dry weights than control plants. Among the studied mycorrhizae species, Glomus intraradices performed better than Glomus mosseae and their mixture as it increased S/R ratio, tiller height and number of leaves.

  17. Effect of Arbuscular Mycorrhiza on Growth of Mucuna pruriens on Soil Contaminated with Heavy Metals Pb and Cd

    OpenAIRE

    Amnah, Rizky; Hanafiah, Asmarlaili S.; Sabrina, T.

    2016-01-01

    Heavy metals is one of the causes of decreasing soil quality and toxicity for plant. Heavy metals can not be degraded and accumulate in plant tissues.Arbuscular mycorrhiza can reduce toxicity, improve the plants tolerance and growth in soil contaminated with heavy metals.The objective of this research was to observe the effects of arbuscular mycorrhiza on growth of Mucuna pruriens plants that grow in the soil contaminated by Pb and Cd. This research was done at screen house of Agr...

  18. Comparative studies of the occurrence of arbuscular fungi and mycorrhizae (Glomales in cultivated and uncultivated soils of Poland

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    Janusz Błaszkowski

    2014-08-01

    Full Text Available This paper presents results of 6-year studies on the occurrence of arbuscular fungi and mycorrhizae in cultivated and uncultivated soils of Poland. The comparisons include the include of spore and species densi-lies. and the levels of mycorrhizal colonization. The relationship between the occurrence of arbuscular fungi and mycorrhizae and soil chemical properties was assessed based on analysis of correlation. The distribution of the fungal species found both in Poland and in the world is presented.

  19. A new model of carbon and phosphorus transfers in arbuscular mycorrhizas.

    Science.gov (United States)

    Landis, Frank C; Fraser, Lauchlan H

    2008-01-01

    Existing models of nutrient transfer in arbuscular mycorrhizal (AM) symbioses are inadequate as they do not explain the range of real responses seen experimentally. A computer simulation model was used to evaluate the novel hypotheses that mycorrhizal nutrient transfers were based solely on symbionts' internal needs, and that carbon and phosphorus transfers were quantitatively unlinked. To be plausible, simulated mycorrhizal plants would show a +/-50% variation in weight vs nonmycorrhizal controls, with a normal response distribution (mimicking a real data set). One plant and one arbuscular mycorrhizal fungus (AMF) growing in a soil volume were simulated, using C, P and nitrogen nutrient cycling and stoichiometry. C- and P-exchange rates were independent and could be varied at will. The model was tested at realistic nutrient concentrations and a full range of nutrient exchange rates. The model showed -20% to +55% range in mycorrhizal plant weight distributed close to normal, suggesting that the hypotheses were plausible. The model suggests that theoretical assumptions about mycorrhizas should be reassessed. The model worked only because the symbionts possessed incomplete information on their partner and environmental conditions. Conventional cost-benefit models do not work under these circumstances, but both mutualistic and parasitic interactions were successfully simulated.

  20. SOME PRELIMINARY DATA ABOUT VESICULAR – ARBUSCULAR MYCORRHIZAS AT DIFFERENT SPECIES OF PLANTAGO

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2010-01-01

    Full Text Available Vesicular – arbuscular mycorrhizas are though widely distributed. Root colonization of VAM fungi was studied in seven different species of Plantago. Colonization was high among all species. The highest intensity of root cortex colonization (M%, relative arbuscular richness (A% and arbuscule richness in root fragments were found in the Plantago schwarzenbergiana. Comparison of the VAM colonization in roots from different ecosystems suggested that plants grown in the saline habitats might be more dependence on VAM. There is a suggestion that AM fungi were able to detect variations in land. There is also an indication that VAM abundance was a response to stress.

  1. EFFECT OF ARBUSCULAR MYCORRHIZA FUNGI INOCULATION ON TEAK (Tectona grandis Linn. F AT CIKAMPEK, WEST JAVA

    Directory of Open Access Journals (Sweden)

    Ragil S.B. Irianto

    2005-07-01

    Full Text Available The aim of this study was to identify the effect of Arbuscular Mycorhiza Fungi (AMF on the early growth of teak (Tectona grandis Linn. F plantation. Teak seedlings were inoculated with Glomus aggregatum or Mycofer (mixing of four Arbuscular Mycorrhiza Fungi (AMF : G. margarita, G. manihotis, G. etunicatum and Acalospora spinosa at the time of transplantation. At  three months old the seedlings were planted in Cikampek experimental forest. Results showed that application of G. aggregatum or mycofer to teak could accelerate height and diameter growth by up to 61%and4 7%, respectively, after three months in the field.

  2. [Signal exchange between plants and Arbuscular Mycorrhizae fungi during the early stage of symbiosis - A review].

    Science.gov (United States)

    Duan, Qianqian; Yang, Xiaohong; Huang, Xianzhi

    2015-07-04

    Much is known about Arbuscular Mycorrhizae (AM), an important component of the ecosystem, whereas little is known about the signal exchange that allows mutual recognition and reprograming for the anticipated physical interaction. This review addresses the latest advances of signal exchange between plants and AM, including signal substances and their function, related genes and regulation function in the early stage of plant-fungal symbiosis.

  3. 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

  4. Plant 9-lox oxylipin metabolism in response to arbuscular mycorrhiza.

    Science.gov (United States)

    León Morcillo, Rafael Jorge; Ocampo, Juan A; García Garrido, José M

    2012-12-01

    The establishment of an Arbuscular Mycorrhizal symbiotic interaction (MA) is a successful strategy to substantially promote plant growth, development and fitness. Numerous studies have supported the hypothesis that plant hormones play an important role in the recognition and establishment of symbiosis. Particular attention has been devoted to jasmonic acid (JA) and its derivates, the jasmonates, which are believed to play a major role in AM symbiosis. Jasmonates belong to a diverse class of lipid metabolites known as oxylipins that include other biologically active molecules. Recent transcriptional analyses revealed upregulation of the oxylipin pathway during AM symbiosis in mycorrhizal tomato roots and point a key regulatory feature for oxylipins during AM symbiosis in tomato, particularly these derived from the action of 9-lipoxygenases (9-LOX). In this mini-review we highlight recent progress understanding the function of oxylipins in the establishment of the AM symbiosis and hypothesize that the activation of the 9-LOX pathway might be part of the activation of host defense responses which will then contribute to both, the control of AM fungal spread and the increased resistance to fungal pathogens in mycorrhizal plants.

  5. Plant 9-lox oxylipin metabolism in response to arbuscular mycorrhiza

    Science.gov (United States)

    León Morcillo, Rafael Jorge; Ocampo, Juan A.; García Garrido, José M.

    2012-01-01

    The establishment of an Arbuscular Mycorrhizal symbiotic interaction (MA) is a successful strategy to substantially promote plant growth, development and fitness. Numerous studies have supported the hypothesis that plant hormones play an important role in the recognition and establishment of symbiosis. Particular attention has been devoted to jasmonic acid (JA) and its derivates, the jasmonates, which are believed to play a major role in AM symbiosis. Jasmonates belong to a diverse class of lipid metabolites known as oxylipins that include other biologically active molecules. Recent transcriptional analyses revealed upregulation of the oxylipin pathway during AM symbiosis in mycorrhizal tomato roots and point a key regulatory feature for oxylipins during AM symbiosis in tomato, particularly these derived from the action of 9-lipoxygenases (9-LOX). In this mini-review we highlight recent progress understanding the function of oxylipins in the establishment of the AM symbiosis and hypothesize that the activation of the 9-LOX pathway might be part of the activation of host defense responses which will then contribute to both, the control of AM fungal spread and the increased resistance to fungal pathogens in mycorrhizal plants. PMID:23073021

  6. Arbuscular mycorrhiza formation and its function under elevated atmospheric O3: A meta-analysis.

    Science.gov (United States)

    Wang, Shuguang; Augé, Robert M; Toler, Heather D

    2017-07-01

    We quantitatively evaluated the effects of elevated O3 on arbuscular mycorrhiza (AM) formation and on AM role in promoting plant growth in regard to several moderating variables (O3 levels, O3 exposure duration, plant types, AM fungi family, and additional stress) by means of meta-analysis of published data. The analysis consisted of 117 trials representing 20 peer-reviewed articles and 16 unpublished trials. Relative to non-mycorrhizal controls, AM inoculation did not significantly alter plant growth (shoot biomass, root biomass, total biomass and plant height) when O3 concentration was less than 80 ppb, but at concentrations above 80 ppb symbiosis was associated with increases of 68% in shoot biomass and 131% in root biomass. AM effects on plant growth were affected by the duration of O3 exposure but did not differ much with AM fungi taxa or plant type. AM symbiosis has also led to higher yields under O3 stress, relative to the non-mycorrhizal plants, and the AM effects have been more pronounced as O3 concentration increases. As with biomass, AM effects on yield have been affected by the duration of O3 exposure, with the greatest increase (100%) occurring at 61-90 d. AM-induced promotion of yield differed with fungal species but not with plant type or other abiotic stress. Colonization of roots by AM fungi has been negatively affected by elevated O3 compared to ambient O3; total mycorrhizal colonization rate (MCR), arbuscular MCR, vesicular MCR and hyphal coil MCR declined as O3 levels rose. AM colonization rates were affected by duration of O3 exposure, plant type, AM fungal taxa and other concurrent stresses in most cases. The analysis showed that AM inoculation has the potential to ameliorate detrimental effects of elevated O3 on plant growth and productivity, despite colonization rates being negatively affected by elevated O3. Copyright © 2017. Published by Elsevier Ltd.

  7. Micorriza arbuscular e a tolerância das plantas ao estresse Arbuscular mycorrhiza and plant tolerance to stress

    Directory of Open Access Journals (Sweden)

    Muriel da Silva Folli-Pereira

    2012-12-01

    Full Text Available Fungos micorrízicos arbusculares (FMAs são fungos de solo, biotróficos obrigatórios e formadores da simbiose mutualista mais comum na natureza: a micorriza arbuscular (MA. Essa associação ocorre nas raízes da maioria das plantas terrestres, promovendo melhorias no crescimento, desenvolvimento e aumento na tolerância e, ou, resistência das plantas a vários agentes ambientais adversos. Além disso, os FMAs podem ser utilizados como potenciais agentes de controle biológico de doenças de plantas. Esses fungos produzem ainda glomalina, uma proteína que desempenha papel fundamental na estabilidade do solo e bioestabilização de solos contaminados. As diferentes respostas das plantas a essa simbiose podem ser atribuídas à diversidade funcional das MAs, em função da interação FMA-planta-condições ambientais. O estabelecimento e funcionamento da MA durante as condições de estresse envolvem um complexo processo de reconhecimento e desenvolvimento, concomitantemente às alterações bioquímicas, fisiológicas e moleculares em ambos os simbiontes. Além disso, a colonização micorrízica das raízes tem impacto significativo na expressão de genes de diversas plantas que codificam proteínas presumivelmente envolvidas na tolerância ao estresse. Nesse contexto, considerando que os FMAs são essenciais no estabelecimento e adaptação das plantas em locais perturbados, nesta revisão são abordados os mecanismos fisiológicos e moleculares da associação MA responsáveis por essa adaptação e pela maior tolerância das plantas ao estresse.Arbuscular mycorrhizal fungi (AMF are soil fungi, obligate biotrophic fungi and form the most common mutualistic symbiosis in nature: the arbuscular mycorrhiza (AM. This association occurs on the roots of most plants, promoting improvements in plant growth and development and increasing tolerance and/or plant resistance to several adverse environmental agents. In addition, AMF can be a potential

  8. Using mycorrhiza-defective mutant genotypes of non-legume plant species to study the formation and functioning of arbuscular mycorrhiza: a review.

    Science.gov (United States)

    Watts-Williams, Stephanie J; Cavagnaro, Timothy R

    2015-11-01

    A significant challenge facing the study of arbuscular mycorrhiza is the establishment of suitable non-mycorrhizal treatments that can be compared with mycorrhizal treatments. A number of options are available, including soil disinfection or sterilisation, comparison of constitutively mycorrhizal and non-mycorrhizal plant species, comparison of plants grown in soils with different inoculum potential and the comparison of mycorrhiza-defective mutant genotypes with their mycorrhizal wild-type progenitors. Each option has its inherent advantages and limitations. Here, the potential to use mycorrhiza-defective mutant and wild-type genotype plant pairs as tools to study the functioning of mycorrhiza is reviewed. The emphasis of this review is placed on non-legume plant species, as mycorrhiza-defective plant genotypes in legumes have recently been extensively reviewed. It is concluded that non-legume mycorrhiza-defective mutant and wild-type pairs are useful tools in the study of mycorrhiza. However, the mutant genotypes should be well characterised and, ideally, meet a number of key criteria. The generation of more mycorrhiza-defective mutant genotypes in agronomically important plant species would be of benefit, as would be more research using these genotype pairs, especially under field conditions.

  9. 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...

  10. The role of arbuscular mycorrhizas in reducing soil nutrient loss

    NARCIS (Netherlands)

    Cavagnaro, Timothy R.; Bender, S. Franz; Asghari, Hamid R.; van der Heijden, Marcel G A

    2015-01-01

    Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular

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

    Science.gov (United States)

    Tian, Lei; Li, Yuanjing; Tian, Chunjie

    2016-01-04

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

  12. How membranes shape plant symbioses: Signaling and transport in nodulation and arbuscular mycorrhiza

    Directory of Open Access Journals (Sweden)

    Laure eBapaume

    2012-10-01

    Full Text Available As sessile organisms that cannot evade adverse environmental conditions, plants have evolved various adaptive strategies to cope with environmental stresses. One of the most successful adaptations is the formation of symbiotic associations with beneficial microbes. In these mutualistic interactions the partners exchange essential nutrients and improve their resistance to biotic and abiotic stresses. In arbuscular mycorrhiza (AM and in root nodule symbiosis (RNS, AM fungi and rhizobia, respectively, penetrate roots and accommodate within the cells of the plant host. In these endosymbiotic associations, both partners keep their plasma membranes intact and use them to control the bidirectional exchange of signaling molecules and nutrients. Intracellular accommodation requires the exchange of symbiotic signals and the reprogramming of both interacting partners. This involves fundamental changes at the level of gene expression and of the cytoskeleton, as well as of organelles such as plastids, endoplasmic reticulum (ER, and the central vacuole. Symbiotic cells are highly compartmentalized and have a complex membrane system specialized for the diverse functions in molecular communication and nutrient exchange. Here, we discuss the roles of the different cellular membrane systems and their symbiosis-related proteins in AM and RNS, and we review recent progress in the analysis of membrane proteins involved in endosymbiosis.

  13. How membranes shape plant symbioses: signaling and transport in nodulation and arbuscular mycorrhiza

    Science.gov (United States)

    Bapaume, Laure; Reinhardt, Didier

    2012-01-01

    As sessile organisms that cannot evade adverse environmental conditions, plants have evolved various adaptive strategies to cope with environmental stresses. One of the most successful adaptations is the formation of symbiotic associations with beneficial microbes. In these mutualistic interactions the partners exchange essential nutrients and improve their resistance to biotic and abiotic stresses. In arbuscular mycorrhiza (AM) and in root nodule symbiosis (RNS), AM fungi and rhizobia, respectively, penetrate roots and accommodate within the cells of the plant host. In these endosymbiotic associations, both partners keep their plasma membranes intact and use them to control the bidirectional exchange of signaling molecules and nutrients. Intracellular accommodation requires the exchange of symbiotic signals and the reprogramming of both interacting partners. This involves fundamental changes at the level of gene expression and of the cytoskeleton, as well as of organelles such as plastids, endoplasmic reticulum (ER), and the central vacuole. Symbiotic cells are highly compartmentalized and have a complex membrane system specialized for the diverse functions in molecular communication and nutrient exchange. Here, we discuss the roles of the different cellular membrane systems and their symbiosis-related proteins in AM and RNS, and we review recent progress in the analysis of membrane proteins involved in endosymbiosis. PMID:23060892

  14. Arbuscular mycorrhizae increase the arsenic translocation factor in the As hyperaccumulating fern Pteris vittata L.

    Science.gov (United States)

    Trotta, A; Falaschi, P; Cornara, L; Minganti, V; Fusconi, A; Drava, G; Berta, G

    2006-09-01

    Phytoremediation techniques are receiving more attention as decontaminating strategies. Phytoextraction makes use of plants to transfer contaminants from soil to the aboveground biomass. This research is devoted to study the effects of arbuscular mycorrhizae (AM) on growth and As hyperaccumulation in the Chinese brake fern Pteris vittata. We grew for 45 days P. vittata sporophytes, infected or not infected with the AM fungi Glomus mosseae or Gigaspora margarita, in a hydroponic system on quartz sand. As-treated plants were weekly fed with 25 ppm As. The As treatment produced a dramatic increase of As concentration in pinnae and a much lower increase in roots of both mycorrhizal and control plants. Mycorrhization increased pinnae dry weight (DW) (G. margarita = G. mosseae) and leaf area (G. margarita > G. mosseae), strongly reduced root As concentration (G. mosseae > G. margarita), and increased the As translocation factor (G. mosseae > G. margarita). The concentration of phosphorus in pinnae and roots was enhanced by both fungi (G. margarita > G. mosseae). The quantitatively different effects of the two AM fungi on plant growth as well as on As and P distribution in the fern suggest that the As hyperaccumulation in P. vittata can be optimized by a careful choice of the symbiont.

  15. 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.

  16. [Development of Arbuscular Mycorrhiza in Highly Responsive and Mycotrophic Host Plant-Black Medick (Medicago lupulina L.)].

    Science.gov (United States)

    Yurkova, A P; Jacobi, L M; Gapeeva, N E; Stepanova, G V; Shishova, M F

    2015-01-01

    The main phases of arbuscular mycorrhiza (AM) development were analyzed in black medick (Medicago lupulina) with Glomus intraradices. Methods of light and transmission electron microscopy were used to investigate AM. The first mycorrhization was identified on the seventh day after sowing. M. lupulina with AM-fungus Glomus intraradices formed Arum type of AM. Roots of black medick at fruiting stage (on the 88th day) were characterized by the development of forceful mycelium. The thickness of mycelium was comparable with the vascular system of root central cylinder. The development of vesicules into intraradical spores was shown. Micelium, arbuscules, and vesicules developed in close vicinity to the division zone of root tip. This might be evidence of an active symbiotic interaction between partners. All stages of fungal development and breeding, including intraradical spores (in inter-cellular matrix of root cortex), were identified in the roots of black medick, which indicated an active utilization of host plant nutrient substrates by the mycosymbiont. Plant cell cytoplasm extension was identified around young arbuscular branches but not for intracellular hyphae. The presence of active symbiosis was confirmed by increased accumulation of phosphorus in M. lupulina root tissues under conditions of G. intraradices inoculation and low phosphorus level in the soil. Thus, black medick cultivar-population can be characterized as an ecologically obligate mycotrophic plant under conditions of low level of available phosphorus in the soil. Specific features of AM development in intensively mycotrophic black medick, starting from the stage of the first true leaf until host plant fruiting, were evaluated. The obtained plant-microbe system is a perspective model object for further ultracytological and molecular genetic studies of the mechanisms controlling arbuscular mycorrhiza symbiotic efficiency, including selection and investigation of new symbiotic plant mutants.

  17. Medicago truncatula gene responses specific to arbuscular mycorrhiza interactions with different species and genera of Glomeromycota.

    Science.gov (United States)

    Massoumou, M; van Tuinen, D; Chatagnier, O; Arnould, C; Brechenmacher, L; Sanchez, L; Selim, S; Gianinazzi, S; Gianinazzi-Pearson, V

    2007-05-01

    Plant genes exhibiting common responses to different arbuscular mycorrhizal (AM) fungi and not induced under other biological conditions have been sought for to identify specific markers for monitoring the AM symbiosis. A subset of 14 candidate Medicago truncatula genes was identified as being potentially mycorrhiza responsive in previous cDNA microarray analyses and exclusive to cDNA libraries derived from mycorrhizal root tissues. Transcriptional activity of the selected plant genes was compared during root interactions with seven AM fungi belonging to different species of Glomus, Acaulospora, Gigaspora, or Scutellospora, and under widely different biological conditions (mycorrhiza, phosphate fertilization, pathogenic/beneficial microbe interactions, incompatible plant genotype). Ten of the M. truncatula genes were commonly induced by all the tested AM fungal species, and all were activated by at least two fungi. Most of the plant genes were transcribed uniquely in mycorrhizal roots, and several were already active at the appressorium stage of fungal development. Novel data provide evidence that common recognition responses to phylogenetically different Glomeromycota exist in plants during events that are unique to mycorrhiza interactions. They indicate that plants should possess a mycorrhiza-specific genetic program which is comodulated by a broad spectrum of AM fungi.

  18. Nitrogen and carbon/nitrogen dynamics in arbuscular mycorrhiza: the great unknown.

    Science.gov (United States)

    Corrêa, A; Cruz, C; Ferrol, N

    2015-10-01

    Many studies have established that arbuscular mycorrhizal fungi transfer N to the host plant. However, the role and importance of arbuscular mycorrhiza (AM) in plant N nutrition is still uncertain, as are the C/N interactions within the symbiosis. Published reports provide differing, and often contradictory, results that are difficult to combine in a coherent framework. This review explores questions such as: What makes the difference between a positive and a negative effect of AM on plant N nutrition? Is the mycorrhizal N response (MNR) correlated to the mycorrhizal growth response (MGR), and how or under which conditions? Is the MNR effect on plant growth C mediated? Is plant C investment on fungal growth related to N needs or N benefit? How is the N for C trade between symbionts regulated? The patternless nature of current knowledge is made evident, and possible reasons for this are discussed.

  19. Preliminary assessment of plant community structure and arbuscular mycorrhizas in rangeland habitats of Cholistan desert, Pakistan.

    Science.gov (United States)

    Chaudhry, M S; Batool, Z; Khan, A G

    2005-11-01

    Plant species dominance and arbuscular mycorrhizas (AMs) were evaluated in four different habitats of Cholistan desert, Pakistan. The sites were selected on the basis of variations in topography, floristic composition and biotic interference. The phytosociological data revealed obvious differences in the floristic composition, plant species diversity, AM colonization and arbuscular mycorrhizal fungi (AMF) spore densities in the rhizospheres. The vegetation pattern and composition was governed by topography and edaphic characteristics of a particular site. Grasses were dominant and main components of vegetation at all the study sites and were invariably mycorrhizal. Some plant species were mycorrhizal at one site but non-mycorrhizal at the other. The AMF survey reported here offers an important starting point from which to analyse AMF community structure in different phytosociological habitats and land uses of Cholistan desert.

  20. The influence of arbuscular mycorrhizae on root precision nutrient foraging of two pioneer plant species during early reclamation

    Science.gov (United States)

    Boldt-Burisch, Katja; Naeth, M. Anne

    2017-04-01

    On many post mining sites in the Lusatian Mining District (East Germany) soil heterogeneity consists of sandy soil with embedded clay-silt fragments. Those clays silt fragments might act as nutrient hotspots. Arbuscular mycorrhizal fungi in an infertile ecosystem could enhance a plant's ability to selectively forage for those nutrients and thus to improve plants nutrient supply. In our study we investigated whether silt-clay fragments within a sandy soil matrix induced preferential root growth of Lotus corniculatus and Calamagrostis epigeios, whether arbuscular mycorrhizae influenced root foraging patterns, and to what extent selective rooting in clay silt fragments influenced plant growth were addressed in this research. Soil types were sterile and non-sterile sandy soil and clay-silt fragments. Treatments were with and without arbuscular mycorrhizae, with and without soil solution, and soil solution and mycorrhizal inoculum combined. Root biomass, root density and intraradical fungal alkaline phosphatase activity and frequency were determined in fragments relative to sandy soil. Furthermore, temporal relationship of number of roots in fragments and plant height was assessed. Lotus corniculatus showed strong selective rooting into fragments especially with those plants treated with commercial cultivated arbuscular mycorrhizae; Calamagrostis epigeios did not. Without arbuscular mycorrhizae, L. corniculatus growth was significantly reduced and selective rooting did not occur. Selective rooting induced significant growth spurts of L. corniculatus. Roots in fragments had higher fungal alkaline phosphatase activity suggesting that mycorrhizal efficiency and related plants phosphorus supply is enhanced in roots in fragments. The application of cultivated arbuscular mycorrhizal fungi significantly and quickly influenced root foraging patterns, especially those of L. corniculatus, suggesting mycorrhizae may also enhance the ability of other plants to selectively forage

  1. Arbuscular mycorrhizae of dominant plant species in Yungas forests, Argentina.

    Science.gov (United States)

    Becerra, Alejandra G; Cabello, Marta; Zak, Marcelo R; Bartoloni, Norberto

    2009-01-01

    In Argentina the Yungas forests are among the ecosystems most affected by human activity, with loss of biodiversity. To assess the arbuscular mycorrhizal (AM) colonization and the arbuscular mycorrhizal fungi (AMF) spore numbers in these ecosystems, the roots of the most dominant native plants (one tree, Alnus acuminata; three herbaceous, Duchesnea indica, Oxalis conorrhiza, Trifolium aff. repens; and one shrub, Sambucus peruviana) were studied throughout the year from two sites of Yungas forests. Assessments of mycorrhizal colonization (percent root length, intraradical structures) were made by washing and staining the roots. Soil samples of each plant species were pooled and subsamples were obtained to determine AM spore numbers. The herbaceous species formed both Arum- and Paris-type morphologies, whereas the tree and the shrub species formed respectively single structural types of Arum- and Paris-type. AM colonization, intraradical fungi structures and AMF spore numbers displayed variation in species, seasons and sites. D. indica showed the highest AM colonization, whereas the highest spore numbers was observed in the rhizosphere of A. acuminata. No correlation was observed between spore numbers and root length percentage colonized by AM fungi. Results of this study showed that Alnus acuminata is facultatively AM. The AM colonization, intraradical fungi structures and AMF spore numbers varied in species depending on phenological, climatic and edaphic conditions.

  2. Role of arbuscular mycorrhiza in alleviating salinity stress in wheat (Triticum aestivum L.) grown under ambient and elevated CO2

    DEFF Research Database (Denmark)

    Zhu, X.; Song, F.; Liu, S.

    2016-01-01

    Plant growth and development are influenced by future elevated atmospheric CO2 concentration and increased salinity stress. AM (arbuscular mycorrhiza) symbiosis has been shown to improve plant growth and resistance to environmental stresses. The aim of this study was to investigate the potential...

  3. 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...

  4. 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...

  5. Arbuscular mycorrhiza in species of Commelinidae (Liliopsida in the state of Pernambuco (Brazil

    Directory of Open Access Journals (Sweden)

    Silva Gladstone Alves da

    2001-01-01

    Full Text Available Mycorrhiza are a mutualistic symbiosis between fungi and plant roots, the main benefit to the plant being increased nutrient uptake. The arbuscular is the most important kind of mycorrhiza for agriculture and it is widespread in occurrence and distribution in most ecosystems. The aim of this work was to study the mycorrhizal status of the species of Commelinidae that occur in the State of Pernambuco. Plant roots, collected in ten municipalities, were washed, cleared in KOH, stained with Trypan blue in lactoglycerol and observed under a light microscope in order to assess presence and identification of the mycorrhizal type. Percentage of root colonization was evaluated by the gridline intersect method. Forty specimens representing 30 species were observed. From these specimens, 70% were colonized by arbuscular mycorrhizal fungi (AMF. In one family (Typhaceae, mycorrhizal structures were not observed, in two of them (Eriocaulaceae and Juncaceae all specimens showed the association, and three families (Commelinaceae, Cyperaceae and Poaceae presented specimens with or without AMF. In some of the roots, other fungi were observed together with the AMF. The results indicate that AMF are widely distributed among species of Commelinidae in Pernambuco, being probably important for their establishment in the areas visited.

  6. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems.

    Science.gov (United States)

    de Azevedo, Lucas Carvalho Basilio; Stürmer, Sidney Luiz; Lambais, Marcio Rodrigues

    2014-01-01

    Sugarcane (Saccharum spp.) is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF) and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning). Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development.

  7. Ethylene-dependent/ethylene-independent ABA regulation of tomato plants colonized by arbuscular mycorrhiza fungi.

    Science.gov (United States)

    Martín-Rodríguez, José Ángel; León-Morcillo, Rafael; Vierheilig, Horst; Ocampo, Juan Antonio; Ludwig-Müller, Jutta; García-Garrido, José Manuel

    2011-04-01

    We investigated the relationship between ABA and ethylene regulating the formation of the arbuscular mycorrhiza (AM) symbiosis in tomato (Solanum lycopersicum) plants and tried to define the specific roles played by each of these phytohormones in the mycorrhization process. We analysed the impact of ABA biosynthesis inhibition on mycorrhization by Glomus intraradices in transgenic tomato plants with an altered ethylene pathway. We also studied the effects on mycorrhization in sitiens plants treated with the aminoethoxyvinyl glycine hydrochloride (AVG) ethylene biosynthesis inhibitor and supplemented with ABA. In addition, the expression of plant and fungal genes involved in the mycorrhization process was studied. ABA biosynthesis inhibition qualitatively altered the parameters of mycorrhization in accordance with the plant's ethylene perception and ethylene biosynthesis abilities. Inhibition of ABA biosynthesis in wild-type plants negatively affected all the mycorrhization parameters studied, while tomato mutants impaired in ethylene synthesis only showed a reduced arbuscular abundance in mycorrhizal roots. Inhibition of ethylene synthesis in ABA-deficient sitiens plants increased the intensity of mycorrhiza development, while ABA application rescued arbuscule abundance in the root's mycorrhizal zones. The results of our study show an antagonistic interaction between ABA and ethylene, and different roles of each of the two hormones during AM formation. This suggests that a dual ethylene-dependent/ethylene-independent mechanism is involved in ABA regulation of AM formation. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  8. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems

    Science.gov (United States)

    de Azevedo, Lucas Carvalho Basilio; Stürmer, Sidney Luiz; Lambais, Marcio Rodrigues

    2014-01-01

    Sugarcane (Saccharum spp.) is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF) and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning). Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development. PMID:25477936

  9. Early changes in arbuscular mycorrhiza development in sugarcane under two harvest management systems

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    Lucas Carvalho Basilio de Azevedo

    2014-09-01

    Full Text Available Sugarcane (Saccharum spp. is grown on over 8 million ha in Brazil and is used to produce ethanol and sugar. Some sugarcane fields are burned to facilitate harvesting, which can affect the soil microbial community. However, whether sugarcane pre-harvest burning affects the community of arbuscular mycorrhizal fungi (AMF and symbioses development is not known. In this study, we investigated the early impacts of harvest management on AMF spore communities and root colonization in three sugarcane varieties, under two harvest management systems (no-burning and pre-harvest burning. Soil and root samples were collected in the field after the first harvest of sugarcane varieties SP813250, SP801842, and RB72454, and AMF species were identified based on spore morphology. Diversity indices were determined based on spore populations and root colonization determined as an indicator of symbioses development. Based on the diversity indices, spore number and species occurrence in soil, no significant differences were observed among the AMF communities, regardless of harvest management type, sugarcane variety or interactions between harvest management type and sugarcane variety. However, mycorrhiza development was stimulated in sugarcane under the no-burning management system. Our data suggest that the sugarcane harvest management system may cause early changes in arbuscular mycorrhiza development.

  10. High specificity in plant leaf metabolic responses to arbuscular mycorrhiza.

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    Schweiger, Rabea; Baier, Markus C; Persicke, Marcus; Müller, Caroline

    2014-05-22

    The chemical composition of plants (phytometabolome) is dynamic and modified by environmental factors. Understanding its modulation allows to improve crop quality and decode mechanisms underlying plant-pest interactions. Many studies that investigate metabolic responses to the environment focus on single model species and/or few target metabolites. However, comparative studies using environmental metabolomics are needed to evaluate commonalities of chemical responses to certain challenges. We assessed the specificity of foliar metabolic responses of five plant species to the widespread, ancient symbiosis with a generalist arbuscular mycorrhizal fungus. Here we show that plant species share a large 'core metabolome' but nevertheless the phytometabolomes are modulated highly species/taxon-specifically. Such a low conservation of responses across species highlights the importance to consider plant metabolic prerequisites and the long time of specific plant-fungus coevolution. Thus, the transferability of findings regarding phytometabolome modulation by an identical AM symbiont is severely limited even between closely related species.

  11. Co-occurrence of Arum- and Paris-type morphologies of arbuscular mycorrhizae in cucumber and tomato.

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    Kubota, Mayumi; McGonigle, Terence P; Hyakumachi, Mitsuro

    2005-03-01

    Colonization by arbuscular mycorrhizal (AM) fungi was investigated in cucumber (Cucumis sativus), tomato (Lycopersicon esculentum) and Clethra barbinervis (Ericales) grown in field-collected soil known from previous studies to generate Paris-type arbuscular mycorrhizae in C. barbinervis. Spores of Paraglomus, Acaulospora, Glomus, and Gigaspora were found in the soil. Formation of hyphal coils and arbusculate coils of Paris-type mycorrhizae and of arbuscules of Arum-type mycorrhizae in roots raised in this soil in the growth chamber were compared with the detection of DNA of AM fungi from the same root systems using Glomales-specific primers. Only Paris-type mycorrhizae with extensive arbusculate coils developed in C. barbinervis, but cucumber and tomato developed both Paris- and Arum-types in the same root systems. Glomaceae and Archaeosporaceae and/or Paraglomaceae were detected strongly in the DNA from both cucumber and tomato roots, in which Arum-type mycorrhizae were observed. In contrast, DNA of Glomaceae was detected more sparingly in C. barbinervis, in which Paris-type mycorrhizae dominated. Acaulosporaceae and Gigasporaceae were strongly detected in the DNA from both C. barbinervis and tomato, whereas they were more weakly detected in cucumber. These results indicate that the morphology of colonization is strongly influenced by the selection of fungi to colonize the host plant from among those in the soil environment.

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

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    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.

  13. Plant growth, phosphorus nutrition, and root morphological responses to arbuscular mycorrhizas, phosphorus fertilization, and intraspecific density.

    Science.gov (United States)

    Schroeder, M S; Janos, D P

    2005-05-01

    We examined the effects of arbuscular mycorrhizas (AM), phosphorus fertilization, intraspecific density, and their interaction, on the growth, phosphorus uptake, and root morphology of three facultative mycotrophic crops (Capsicum annuum, Zea mays, and Cucurbita pepo). Plants were grown in pots with or without AM at three densities and four phosphorus availabilities for 10 weeks. AM colonization, plant weight, and shoot phosphorus concentration were measured at harvest. Root morphology was assessed for C. annuum and Z. mays. Phosphorus fertilization reduced but did not eliminate AM colonization of all species. AM, phosphorus, and density interacted significantly to modify growth of C. annuum and C. pepo such that increased density and phosphorus diminished beneficial effects of AM. Increased density reduced positive effects of AM on C. annuum and C. pepo shoot phosphorus concentrations. AM altered both Z. mays and C. annuum root morphology in ways that complemented potential phosphorus uptake by mycorrhizas, but increased density and phosphorus diminished these effects. We infer that increased density predominantly influenced plant responses by affecting whether or not carbon (photosynthate) or phosphorus limited plant growth. By exacerbating carbon limitation, high density reduced the benefit/cost ratio of mycorrhizas and minimized their effects.

  14. Agroecology: the key role of arbuscular mycorrhizas in ecosystem services.

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    Gianinazzi, Silvio; Gollotte, Armelle; Binet, Marie-Noëlle; van Tuinen, Diederik; Redecker, Dirk; Wipf, Daniel

    2010-11-01

    The beneficial effects of arbuscular mycorrhizal (AM) fungi on plant performance and soil health are essential for the sustainable management of agricultural ecosystems. Nevertheless, since the 'first green revolution', less attention has been given to beneficial soil microorganisms in general and to AM fungi in particular. Human society benefits from a multitude of resources and processes from natural and managed ecosystems, to which AM make a crucial contribution. These resources and processes, which are called ecosystem services, include products like food and processes like nutrient transfer. Many people have been under the illusion that these ecosystem services are free, invulnerable and infinitely available; taken for granted as public benefits, they lack a formal market and are traditionally absent from society's balance sheet. In 1997, a team of researchers from the USA, Argentina and the Netherlands put an average price tag of US $33 trillion a year on these fundamental ecosystem services. The present review highlights the key role that the AM symbiosis can play as an ecosystem service provider to guarantee plant productivity and quality in emerging systems of sustainable agriculture. The appropriate management of ecosystem services rendered by AM will impact on natural resource conservation and utilisation with an obvious net gain for human society.

  15. Morphological identification of vesicular-arbuscular mycorrhiza on bulbous plants (Taurus mountain in Turkey

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    Karaarslan Emel

    2015-01-01

    Full Text Available This study was conducted to investigate the morphological identification of vesicular-arbuscular mycorrhiza (VAM on bulbous plants in the Taurus Mountains in Turkey. Thirteen soil samples and bulbous roots were taken from the rhizosphere of bulbous plants. The soils were analyzed for the number of VAM spores and chemical and physical properties. In addition, the roots were examined for infection levels, and morphological identification of VAM spores was made. All tested plants are considered mycorrhizal plants. We determined three spore species (Glomus mosseae, Glomus hoi and Scutellospora calospora from the surveyed soils. The spore distribution rates were as follows: G. Mossea 61.54 %, G. Hoi 23.07 % and Scutellospora calospora 15.38 %. Results suggest that VAM fungal spores and root colonization display variation in rhizosphere under bulbous plants in different ecological conditions.

  16. [Potential role of arbuscular mycorrhiza in bioremediation of uranium contaminated environments].

    Science.gov (United States)

    Chen, Bao-Dong; Chen, Mei-Mei; Bai, Ren

    2011-03-01

    With the increasing demand for new energy, nuclear industry has been developing very fast, and uranium (U) pollution becomes a serious environmental problem especially in the mining area. The discharge of U products and wastes can contaminate soil and water, and finally threaten human health. On the other side, as an environment-friendly biotechnology, the importance of mycorrhizal technology in remediation of polluted environments has received much attention in recent years. Following a brief introduction of the environmental impacts of U contamination, this review summarized the effects of arbuscular mycorrhiza (AM) on U uptake and accumulation by plants based on recent research progresses, suggested possible application of AM fungi in remediation of U contaminated environment, and finally discussed about the perspectives in relevant research area.

  17. Moderating mycorrhizas: arbuscular mycorrhizas modify rhizosphere chemistry and maintain plant phosphorus status within narrow boundaries.

    Science.gov (United States)

    Nazeri, Nazanin K; Lambers, Hans; Tibbett, Mark; Ryan, Megan H

    2014-04-01

    Pastures often experience a pulse of phosphorus (P) when fertilized. We examined the role of arbuscular mycorrhizal fungi (AMF) in the uptake of P from a pulse. Five legumes (Kennedia prostrata, Cullen australasicum, Bituminaria bituminosa, Medicago sativa and Trifolium subterraneum) were grown in a moderate P, sterilized field soil, either with (+AMF) or without (-AMF) addition of unsterilized field soil. After 9-10 weeks, half the pots received 15 mg P kg(-1) of soil. One week later, we measured: shoot and root dry weights; percentage of root length colonized by AMF; plant P, nitrogen and manganese (Mn) concentrations; and rhizosphere carboxylates, pH and plant-available P. The P pulse raised root P concentration by a similar amount in uncolonized and colonized plants, but shoot P concentration increased by 143% in uncolonized plants and 53% in colonized plants. Inoculation with AMF decreased the amount of rhizosphere carboxylates by 52%, raised rhizosphere pH by ∼0.2-0.7 pH units and lowered shoot Mn concentration by 38%. We conclude that AMF are not simply a means for plants to enhance P uptake when P is limiting, but also act to maintain shoot P within narrow boundaries and can affect nutrient uptake through their influence on rhizosphere chemistry. © 2013 John Wiley & Sons Ltd.

  18. The importance of arbuscular mycorrhiza for Cyclamen purpurascens subsp. immaculatum endemic in Slovakia.

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    Rydlová, Jana; Sýkorová, Zuzana; Slavíková, Renata; Turis, Peter

    2015-11-01

    At present, there is no relevant information on arbuscular mycorrhiza and the effect of the symbiosis on the growth of wild populations of cyclamens. To fill this gap, two populations of Cyclamen purpurascens subsp. immaculatum, endemic in Nízke Tatry (NT) mountains and Veľká Fatra (VF) mountains, Slovakia, were studied in situ as well as in a greenhouse pot experiment. For both populations, mycorrhizal root colonization of native plants was assessed, and mycorrhizal inoculation potential (MIP) of the soils at the two sites was determined in 3 consecutive years. In the greenhouse experiment, the growth response of cyclamens to cross-inoculation with arbuscular mycorrhizal fungi (AMF) was tested: plants from both sites were grown in their native soils and inoculated with a Septoglomus constrictum isolate originating either from the same or from the other plant locality. Although the MIP of soil at the NT site was significantly higher than at the VF site, the level of AMF root colonization of C. purpurascens subsp. immaculatum plants in the field did not significantly differ between the two localities. In the greenhouse experiment, inoculation with AMF generally accelerated cyclamen growth and significantly increased all growth parameters (shoot dry weight, leaf number and area, number of flowers, tuber, and root dry weight) and P uptake. The two populations of C. purpurascens subsp. immaculatum grown in their native soils, however, differed in their response to inoculation. The mycorrhizal growth response of NT plants was one-order higher compared to VF plants, and all their measured growth parameters were stimulated regardless of the fungal isolates' origin. In the VF plants, only the non-native (NT originating) isolate showed a significant positive effect on several growth traits. It can be concluded that mycorrhiza significantly increased fitness of C. purpurascens subsp. immaculatum, despite the differences between plant populations, implying that AMF

  19. Phosphorus Effects on Metabolic Processes in Monoxenic Arbuscular Mycorrhiza Cultures1

    Science.gov (United States)

    Olsson, Pål Axel; van Aarle, Ingrid M.; Allaway, William G.; Ashford, Anne E.; Rouhier, Hervé

    2002-01-01

    The influence of external phosphorus (P) on carbon (C) allocation and metabolism as well as processes related to P metabolism was studied in monoxenic arbuscular mycorrhiza cultures of carrot (Daucus carota). Fungal hyphae of Glomus intraradices proliferated from the solid minimal medium containing the colonized roots into C-free liquid minimal medium with different P treatments. The fungus formed around three times higher biomass in P-free liquid medium than in medium with 2.5 mm inorganic P (high-P). Mycelium in the second experiment was harvested at an earlier growth stage to study metabolic processes when the mycelium was actively growing. P treatment influenced the root P content and [13C]glucose administered to the roots 7 d before harvest gave a negative correlation between root P content and 13C enrichment in arbuscular mycorrhiza fungal storage lipids in the extraradical hyphae. Eighteen percent of the enriched 13C in extraradical hyphae was recovered in the fatty acid 16:1ω5 from neutral lipids. Polyphosphate accumulated in hyphae even in P-free medium. No influence of P treatment on fungal acid phosphatase activity was observed, whereas the proportion of alkaline-phosphatase-active hyphae was highest in high-P medium. We demonstrated the presence of a motile tubular vacuolar system in G. intraradices. This system was rarely seen in hyphae subjected to the highest P treatment. We concluded that the direct responses of the extraradical hyphae to the P concentration in the medium are limited. The effects found in hyphae seemed instead to be related to increased availability of P to the host root. PMID:12427983

  20. The role of arbuscular mycorrhizae in primary succession: differences and similarities across habitats

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    Z. Kikvidze

    2010-12-01

    Full Text Available Primary succession is an ecological process of fundamental importance referring to the development of vegetation on areas not previously occupied by a plant community. The bulk of knowledge on primary succession comes from areas affected by relatively recent volcanic eruptions, and highlights the importance of symbiosis between host plants and fungi for the initial stages of succession. Arbuscular mycorrhizas (AM are of particular interest as they are often present from the very beginning of primary succession and because they show different relationships with pioneer and late-successional species, which suggests they may be involved in important, yet unknown, ecological mechanisms of succession. We review existing knowledge based on case studies from the volcanic desert of Mount Fuji, Japan, where primary succession was examined intensively and which represents one of the best-known cases on the role of AM in primary succession. We also assess the potential of sand dunes and semi-arid, erosion-prone systems for addressing the role of mycorrhizas in primary succession. Analyzing primary succession under different ecological systems is critical to understand the role of AM in this basic process. While volcanoes and glaciers are restricted to particular mountainous areas, naturally eroded areas and sand dunes are more common and easily accessible, making them attractive models to study primary succession.

  1. Arbuscular mycorrhiza formation in cordate gametophytes of two ferns, Angiopteris lygodiifolia and Osmunda japonica.

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    Ogura-Tsujita, Yuki; Sakoda, Aki; Ebihara, Atsushi; Yukawa, Tomohisa; Imaichi, Ryoko

    2013-01-01

    Mycorrhizal symbiosis is common among land plants including pteridophytes (monilophytes and lycophytes). In pteridophytes with diplohaplontic life cycle, mycorrhizal formations were mostly reported for sporophytes, but very few for gametophytes. To clarify the mycorrhizal association of photosynthetic gametophytes, field-collected gametophytes of Angiopteris lygodiifolia (Marattiaceae, n = 52) and Osmunda japonica (Osmundaceae, n = 45) were examined using microscopic and molecular techniques. Collected gametophytes were mostly cut into two pieces. One piece was used for light and scanning microscopic observations, and the other for molecular identification of plant species (chloroplast rbcL sequences) and mycorrhizal fungi (small subunit rDNA sequences). Microscopic observations showed that 96 % (50/52) of Angiopteris and 95 % (41/43) of Osmunda gametophytes contained intracellular hyphae with arbuscules and/or vesicles and fungal colonization was limited to the inner tissue of the thick midribs (cushion). Fungal DNA analyses showed that 92 % (48/52) of Angiopteris and 92 % (35/38) of Osmunda have sequences of arbuscular mycorrhizal fungi, which were highly divergent but all belonged to Glomus group A. These results suggest that A. lygodiifolia and O. japonica gametophytes consistently form arbuscular mycorrhizae. Mycorrhizal formation in wild fern gametophytes, based on large-scale sampling with molecular identification of host plant species, was demonstrated for the first time.

  2. Carbon Uptake and the Metabolism and Transport of Lipids in an Arbuscular Mycorrhiza1

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    Pfeffer, Philip E.; Douds, David D.; Bécard, Guillaume; Shachar-Hill, Yair

    1999-01-01

    Both the plant and the fungus benefit nutritionally in the arbuscular mycorrhizal symbiosis: The host plant enjoys enhanced mineral uptake and the fungus receives fixed carbon. In this exchange the uptake, metabolism, and translocation of carbon by the fungal partner are poorly understood. We therefore analyzed the fate of isotopically labeled substrates in an arbuscular mycorrhiza (in vitro cultures of Ri T-DNA-transformed carrot [Daucus carota] roots colonized by Glomus intraradices) using nuclear magnetic resonance spectroscopy. Labeling patterns observed in lipids and carbohydrates after substrates were supplied to the mycorrhizal roots or the extraradical mycelium indicated that: (a) 13C-labeled glucose and fructose (but not mannitol or succinate) are effectively taken up by the fungus within the root and are metabolized to yield labeled carbohydrates and lipids; (b) the extraradical mycelium does not use exogenous sugars for catabolism, storage, or transfer to the host; (c) the fungus converts sugars taken up in the root compartment into lipids that are then translocated to the extraradical mycelium (there being little or no lipid synthesis in the external mycelium); and (d) hexose in fungal tissue undergoes substantially higher fluxes through an oxidative pentose phosphate pathway than does hexose in the host plant. PMID:10364411

  3. Interactions between arbuscular mycorrhizae and heavy metals under sand culture experiment.

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    Liao, J P; Lin, X G; Cao, Z H; Shi, Y Q; Wong, M H

    2003-02-01

    A sand culture experiment was established to determine interactions between arbuscular mycorrhizae and heavy metals. Mycorrhizal infection rates, spore densities, maize root and shoot weights, and heavy metal contents in maize were as indexes of responses of arbuscular mycorrhizal fungi (Acaulospora laevis, Glomus caledonium and Glomus manihotis) to heavy metals (Cu and Cd). The mycorrhizal infection rates of G. caledonium were the highest among these three mycorrhizal fungi, but the sporulating ability of G. caledonium was the poorest in the heavy metal treatments. The shoot and root weights of non-mycorrhizal plants were usually greater than those of mycorrhizal plants when the Cu concentrations in solutions are less than 3 mg l(-1) or Cd concentrations less than 1 mg l(-1). When Cd concentrations were 0.5 and 1 mg(-1), the root and shoot weights of plants inoculated with A. laevis were significantly (p < 0.05) lower than those of other treatments. Copper concentrations in shoots of mycorrhizal plants were higher than those of non-mycorrhizal ones at all Cu concentrations in solution, especially at low Cu concentrations. As to A. laevis, Cu concentrations in roots and shoots of the host were higher than those of non-mycorrhizal plants in these treatments. Thus A. laevis was sensitive to Cu and Cd, especially Cd, and G. caledonium was more tolerant to these two heavy metals. It is suggested that G. caledonium might be a promising mycorrhizal fungus for bioremediation of heavy metal contaminated soil.

  4. Does responsiveness to arbuscular mycorrhizas depend on plant invasive status?

    Science.gov (United States)

    1. Some posit invasive alien plants are less dependent on mycorrhizal associations than native plants, and thus weak mycorrhizal responsiveness may be a general mechanism of plant invasion. 2. Here, we tested whether mycorrhizal responsiveness varies by plant invasive status while controlling for ph...

  5. Effects of Arbuscular Mycorrhiza on Osmotic Adjustment and Photosynthetic Physiology of Maize Seedlings in Black Soils Region of Northeast China

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    Hongwen Xu

    Full Text Available ABSTRACT To investigate the effect of arbuscular mycorrhiza fungi on maize growth, osmoregulation substances and photosynthetic physiology, a popular maize variety ZD 958 was measured under potted condition. Arbuscular mycorrhiza (AM symbiosis promoted plant growth, and enhanced plant height, leaf length, mean leaf width and dry weight. Higher soluble sugar and protein, but lower proline concentrations were detected in AM seedlings than corresponding non-AM seedlings. Quantum yield of PSII photochemistry and potential photochemical efficiency increased by arbuscular mycorrhiza fungi, meanwhile, AM plants had lower primary fluorescence but higher maximal fluorescence and variable fluorescence than non-AM plants. AM enhanced apparent quantum efficiency, maximum net photosynthetic rate, dark respiration rate and light saturation point, but reduced light compensation point. The conclusion was that, after the seedling inoculated with Glomus. tortuosum, AM symbioses could protect cell from being hurt through regulating substances related to osmotic adjustment, besides, the efficiency of light utilization, the capacity of using low light and the capacity of fitting and using high light were all increased by AM symbiosis.

  6. Fungal genes related to calcium homeostasis and signalling are upregulated in symbiotic arbuscular mycorrhiza interactions.

    Science.gov (United States)

    Liu, Yi; Gianinazzi-Pearson, Vivienne; Arnould, Christine; Wipf, Daniel; Zhao, Bin; van Tuinen, Diederik

    2013-01-01

    Fluctuations in intracellular calcium levels generate signalling events and regulate different cellular processes. Whilst the implication of Ca(2+) in plant responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary messenger in the fungal symbiont. The spatio-temporal expression pattern of putatively Ca(2+)-related genes of Glomus intraradices BEG141 encoding five proteins involved in membrane transport and one nuclear protein kinase, was investigated during the AM symbiosis. Expression profiles related to successful colonization of host roots were observed in interactions of G. intraradices with roots of wild-type Medicago truncatula (line J5) compared to the mycorrhiza-defective mutant dmi3/Mtsym13. Symbiotic fungal activity was monitored using stearoyl-CoA desaturase and phosphate transporter genes. Laser microdissection based-mapping of fungal gene expression in mycorrhizal root tissues indicated that the Ca(2+)-related genes were differentially upregulated in arbuscules and/or in intercellular hyphae. The spatio-temporal variations in gene expression suggest that the encoded proteins may have different functions in fungal development or function during symbiosis development. Full-length cDNA obtained for two genes with interesting expression profiles confirmed a close similarity with an endoplasmic reticulum P-type ATPase and a Vcx1-like vacuolar Ca(2+) ion transporter functionally characterized in other fungi and involved in the regulation of cell calcium pools. Possible mechanisms are discussed in which Ca(2+)-related proteins G. intraradices BEG141 may play a role in mobilization and perception of the intracellular messenger by the AM fungus during symbiotic interactions with host roots. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  7. Arbuscular mycorrhiza fungi mediate soil respiration response to climate change in California grasslands

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    Estruch, Carme; Mcfarland, Jack; Haw, Monica P.; Schulz, Marjorie S.; Pugnaire, Francisco I.; Waldrop, Mark P.

    2017-04-01

    California grasslands store ca. 100 Tg of soil organic carbon (SOC) and almost 40% of those ecosystems are prone to land use changes. The fate of these carbon pools will largely depend on how the main components of soil respiration - i.e., roots, mycorrhiza, and 'bulk soil' communities- respond to such changes. In order to determine the sensitivity to environmental drivers we set up an experiment to address the effect of plant community composition, soil age and warming on soil respiration rate during the 2014-2015 winter. We tested differences among microbial, fungal and root respiration using an exclusion technique to assess the effect of plant community (open grasslands vs oak woodland) in two field sites differing in soil properties as nutrient content, related to geologic soil age (92 and 137 kyr). We also used open top chambers (OTC) to simulate global change effects on grasslands. Our results showed that arbuscular mycorrhizal fungi were the main drivers of differences recorded between soils of different age, and that those differences were linked to nutrient availability. Bulk soil respiration was more sensitive to environmental variation than mycorrhizal or root respiration, indicating that the presence of mycorrhizae and roots can regulate the capacity of CO2 emission to the atmosphere. Soil age affected CO2 flux from grasslands but not under oak canopies, likely due to the high concentration of SOM in oak canopies which moderated any affect of soil mineralogy on nutrient availability. Overall our study shows that the ability of grasslands to mitigate CO2 emissions depends on interactions between vegetation and their rhizosphere on soil microbial communities.

  8. Effects of arbuscular mycorrhizas on ammonia oxidizing bacteria in an organic farm soil.

    Science.gov (United States)

    Cavagnaro, T R; Jackson, L E; Scow, K M; Hristova, K R

    2007-11-01

    Arbuscular mycorrhizal fungi (AMF) are potentially important in nutrient cycling in agricultural soils and particularly in soils managed for organic production; little is known, however, about the interrelationships between AMF and other members of soil microbial communities. Ammonia oxidizing bacteria (AOB) are a trophic group of bacteria having an enormous impact on nitrogen availability in soils and are expected to be influenced by the presence of AMF. In a field study, we utilized a unique genetic system comprised of a mycorrhiza defective tomato mutant (named rmc) and its mycorrhiza wild-type progenitor (named 76RMYC+). We examined the effect of AMF by comparing AOB community composition and populations in soil containing roots of the two tomato genotypes in an organically managed soil. Responses of AOB to soil N and P amendments were also studied in the same experiment. Phylogenetic analysis of cloned AOB sequences, derived from excised denaturing gradient gel electrophoresis (DGGE) bands, revealed that the organic farm soil supported a diverse yet stable AOB community, which was neither influenced by mycorrhizal colonization of roots nor by N and P addition to the soil. Real-time TaqMan polymerase chain reaction (PCR) was used to quantify AOB population sizes and showed no difference between any of the treatments. An alternative real-time PCR protocol for quantification of AOB utilizing SYBR green yielded similar results as the TaqMan real-time PCR method, although with slightly lower resolution. This alternative method is advantageous in not requiring the detailed background information about AOB community composition required for adaptation of the TaqMan system for a new soil.

  9. Influence of arbuscular mycorrhizae on photosynthesis and water status of maize plants under salt stress.

    Science.gov (United States)

    Sheng, Min; Tang, Ming; Chen, Hui; Yang, Baowei; Zhang, Fengfeng; Huang, Yanhui

    2008-09-01

    The influence of arbuscular mycorrhizal (AM) fungus Glomus mosseae on characteristics of the growth, water status, chlorophyll concentration, gas exchange, and chlorophyll fluorescence of maize plants under salt stress was studied in the greenhouse. Maize plants were grown in sand and soil mixture with five NaCl levels (0, 0.5, 1.0, 1.5, and 2.0 g/kg dry substrate) for 55 days, following 15 days of non-saline pretreatment. Under salt stress, mycorrhizal maize plants had higher dry weight of shoot and root, higher relative chlorophyll content, better water status (decreased water saturation deficit, increased water use efficiency, and relative water content), higher gas exchange capacity (increased photosynthetic rate, stomatal conductance and transpiration rate, and decreased intercellular CO(2) concentration), higher non-photochemistry efficiency [increased non-photochemical quenching values (NPQ)], and higher photochemistry efficiency [increased the maximum quantum yield in the dark-adapted state (Fv/Fm), the maximum quantum yield in the light-adapted sate (Fv'/Fm'), the actual quantum yield in the light-adapted steady state (phiPSII) and the photochemical quenching values (qP)], compared with non-mycorrhizal maize plants. In addition, AM symbiosis could trigger the regulation of the energy biturcation between photochemical and non-photochemical events reflected in the deexcitation rate constants (kN, kN', kP, and kP'). All the results show that G. mosseae alleviates the deleterious effect of salt stress on plant growth, through improving plant water status, chlorophyll concentration, and photosynthetic capacity, while the influence of AM symbiosis on photosynthetic capacity of maize plants can be indirectly affected by soil salinity and mycorrhizae-mediated enhancement of water status, but not by the mycorrhizae-mediated enhancement of chlorophyll concentration and plant biomass.

  10. The role of arbuscular mycorrhiza on change of heavy metal speciation in rhizosphere of maize in wastewater irrigated agriculture soil

    Institute of Scientific and Technical Information of China (English)

    HUANG Yi; TAO Shu; CHEN You-jian

    2005-01-01

    To understand the roles of mycorrhiza in metal speciation in the rhizosphere and the impact on increasing host plant tolerance against excessive heavy metals in soil, maize ( Zea mays L. ) inoculated with arbuscular mycorrhizal fungus ( Glomus mosseae) was cultivated in heavy metal contaminated soil. Speciations of copper, zinc and lead in the soil were analyzed with the technique of sequential extraction. The results showed that, in comparison to the bolked soil, the exchangeable copper increased from 26 % to 43 % in non-infected and AM-infected rhizoshpere respectively; while other speciation (organic, carbonate and Fe-Mn oxide copper) remained constant and the organic bound zinc and lead also increased but the exchangeable zinc and lead were undetectable. The organic bound copper, zinc and lead were higher by 15%, 40% and 20%, respectively, in the rhizosphere of arbuscular mycorrhiza infected maize in comparison to the non-infected maize. The results might indicate that mycorrhiza could protect its host plants from the phytotoxicity of excessive copper, zinc and lead by changing the speciation from bio-available to the non-bio-available form. The fact that copper and zinc accumulation in the roots and shoots of mycorrhia infected plants were significantly lower than those in the non-infected plants might also suggest that mycorrhiza efficiently restricted excessive copper and zinc absorptions into the host plants. Compared to the non-infected seedlings, the lead content of infected seedlings was 60% higher in shoots. This might illustrate that mycorrhiza have a different mechanism for protecting its host from excessive lead phytotoxicity by chelating lead in the shoots.

  11. Arbuscular mycorrhiza Symbiosis Induces a Major Transcriptional Reprogramming of the Potato SWEET Sugar Transporter Family.

    Science.gov (United States)

    Manck-Götzenberger, Jasmin; Requena, Natalia

    2016-01-01

    Biotrophic microbes feeding on plants must obtain carbon from their hosts without killing the cells. The symbiotic Arbuscular mycorrhizal (AM) fungi colonizing plant roots do so by inducing major transcriptional changes in the host that ultimately also reprogram the whole carbon partitioning of the plant. AM fungi obtain carbohydrates from the root cortex apoplast, in particular from the periarbuscular space that surrounds arbuscules. However, the mechanisms by which cortical cells export sugars into the apoplast for fungal nutrition are unknown. Recently a novel type of sugar transporter, the SWEET, able to perform not only uptake but also efflux from cells was identified. Plant SWEETs have been shown to be involved in the feeding of pathogenic microbes and are, therefore, good candidates to play a similar role in symbiotic associations. Here we have carried out the first phylogenetic and expression analyses of the potato SWEET family and investigated its role during mycorrhiza symbiosis. The potato genome contains 35 SWEETs that cluster into the same four clades defined in Arabidopsis. Colonization of potato roots by the AM fungus Rhizophagus irregularis imposes major transcriptional rewiring of the SWEET family involving, only in roots, changes in 22 of the 35 members. None of the SWEETs showed mycorrhiza-exclusive induction and most of the 12 induced genes belong to the putative hexose transporters of clade I and II, while only two are putative sucrose transporters from clade III. In contrast, most of the repressed transcripts (10) corresponded to clade III SWEETs. Promoter-reporter assays for three of the induced genes, each from one cluster, showed re-localization of expression to arbuscule-containing cells, supporting a role for SWEETs in the supply of sugars at biotrophic interfaces. The complex transcriptional regulation of SWEETs in roots in response to AM fungal colonization supports a model in which symplastic sucrose in cortical cells could be cleaved

  12. Impacts of manganese mining activity on the environment: interactions among soil, plants, and arbuscular mycorrhiza.

    Science.gov (United States)

    Rivera-Becerril, Facundo; Juárez-Vázquez, Lucía V; Hernández-Cervantes, Saúl C; Acevedo-Sandoval, Otilio A; Vela-Correa, Gilberto; Cruz-Chávez, Enrique; Moreno-Espíndola, Iván P; Esquivel-Herrera, Alfonso; de León-González, Fernando

    2013-02-01

    The mining district of Molango in the Hidalgo State, Mexico, possesses one of the largest deposits of manganese (Mn) ore in the world. This research assessed the impacts of Mn mining activity on the environment, particularly the interactions among soil, plants, and arbuscular mycorrhiza (AM) at a location under the influence of an open Mn mine. Soils and plants from three sites (soil under maize, soil under native vegetation, and mine wastes with some vegetation) were analyzed. Available Mn in both soil types and mine wastes did not reach toxic levels. Samples of the two soil types were similar regarding physical, chemical, and biological properties; mine wastes were characterized by poor physical structure, nutrient deficiencies, and a decreased number of arbuscular mycorrhizal fungi (AMF) spores. Tissues of six plant species accumulated Mn at normal levels. AM was absent in the five plant species (Ambrosia psilostachya, Chenopodium ambrosoides, Cynodon dactylon, Polygonum hydropiperoides, and Wigandia urens) established in mine wastes, which was consistent with the significantly lower number of AMF spores compared with both soil types. A. psilostachya (native vegetation) and Zea mays showed mycorrhizal colonization in their root systems; in the former, AM significantly decreased Mn uptake. The following was concluded: (1) soils, mine wastes, and plant tissues did not accumulate Mn at toxic levels; (2) despite its poor physical structure and nutrient deficiencies, the mine waste site was colonized by at least five plant species; (3) plants growing in both soil types interacted with AMF; and (4) mycorrhizal colonization of A. psilostachya influenced low uptake of Mn by plant tissues.

  13. 苋科植物的丛枝菌根%Arbuscular Mycorrhizae of the Family Amaranthaceae

    Institute of Scientific and Technical Information of China (English)

    杨玲; 王国华; 任立成; 赵之伟

    2002-01-01

    @@ 有些种子植物如莎草科、十字花科、灯心草科、藜科、石竹科等20余科,以往曾被认为不能或不易形成丛枝菌根(郭秀珍等,1989;刘润进等,2000).随着对菌根的深入研究,曾被认为是不易与菌根菌组合的湿地生植物、寄生性植物、或一年生植物都被发现是可以形成内生菌根的(Trappe等,1992).此外,Allen等(1989)研究证实,Salsola kali,Atriplex roseum等生长于沙漠、海滨的藜科植物,进行接种处理后,也能形成丛枝菌根.我们在西双版纳调查热带雨林植物的丛枝菌根状况时,偶然发现刺苋(Amaranthus spinosus Linn.)的根系受到了丛枝菌根真菌的侵染,因此,对苋科植物作了扩大采样调查.本文主要报道从热带采集的5属6种苋科植物的根受丛枝菌根真菌感染形成丛枝菌根(arbuscular mycorrhiza,AM)和这些植物根际士壤中的丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)的状况.

  14. Effects of biochar and Arbuscular mycorrhizae on bioavailability of potentially toxic elements in an aged contaminated soil.

    Science.gov (United States)

    Qiao, Yuhui; Crowley, David; Wang, Kun; Zhang, Huiqi; Li, Huafen

    2015-11-01

    Biochar pyrolyzed from corn stalks at 300°C/500°C and arbuscular mycorrhizae (AMF) were examined independently and in combination as possible treatments for soil remediation contaminated with Cd, Cr, Ni, Cu, Pb, Zn after 35 years following land application of sewage sludge in the 1970s. The results showed that biochar significantly decreased the heavy metal concentrations and their bioavailability for plants, and both biochars had similar such effects. AMF inoculation of corn plants had little effect on heavy metal bioavailability in either control or biochar amended soil, and no interaction between biochar and AMF was observed. Changes in DTPA extractable metals following biochar addition to soil were correlated with metal uptake by plants, whereas pore water metal concentrations were not predictive indicators. This research demonstrates positive benefits from biochar application for contaminated soil remediation, but remain ambiguous with regard to the benefits of simultaneous AMF inoculation on reduction of heavy metal bioavailability. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Barbara Grzybowska

    2011-01-01

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

  16. Influence of Arbuscular mycorrhiza fungi (AMF on drought tolerance and charcoal rot disease of cowpea

    Directory of Open Access Journals (Sweden)

    B.O. Oyewole

    2017-03-01

    Full Text Available The influence of Arbuscular mycorrhiza fungi (AMF (Glomus deserticola and Gigaspora gigantea were evaluated on drought tolerance and charcoal rot disease of cowpea genotypes: IT90K-277-2, IT84S-2246-4 and IT06K123-1. IT90K-277-2 and IT84S-2246-4 were sown in 3 kg of sterilized soil for drought experiment with five treatments. Treatment was established thirty days after germination with inoculation of G. deserticola, the mycorrhizal treated cowpea withstand the water stress and produced high yield. Biocontrol experiment had 2 kg sterilized soil potted into bags with cultivars IT90K-277-2 and IT06K123-1, fourteen treatments were established with soil drenched before planting and simultaneous inoculation. Soil drenched with AMF before planting and inoculation of M. phaseolina after 10 days of germination recorded higher growth parameters, while the simultaneous inoculated plant was the most effective in reducing disease severity. However, simultaneous treatment of G. deserticola, G. gigantea and M. phaseolina were most effective for both growth parameters and reduction of disease severity.

  17. Effect of Arbuscular Mycorrhiza on the Drought Tolerance of Poncirus trifoliata Seedlings

    Institute of Scientific and Technical Information of China (English)

    Wu Qiangsheng; Xia Renxue; Hu Zhengjia

    2006-01-01

    The effects of Glomus mosseae colonization on the plant growth and drought tolerance of 1-year-old trifoliate Poncirus trifoliata seedlings in potted culture were studied in natural water stress and rewatering conditions.Results showed that arbuscular mycorrhizal (AM)inoculation significantly improved the height,stem diameter,and fresh weight of P.trifoliata seedlings before natural water stress.By the end of the experiment,the survival percentage of AM-transplanted seedlings was 8%higher than those of non-AM ones.During water stress and rewatering,AM significantly increased the contents of soluble sugars and proteins in leaves,and enhanced the activities of superoxide dismutase (SOD),guaiacol peroxidase (G-POD),and catalase (CAT) in either seedling leaves or roots,which indicated that AM colonization could improve the osmotic adjustment response of P.trifoliata,enhance its defense system,and alleviate oxidative damages to membrane lipids and proteins.These results demonstrated that the drought tolerance of P.trifoliata seedlings was increased by inoculation with AM fungi.The functional mechanism underlying the observation that mycorrhizas increased the host's drought tolerance was closely related to enzymatic and nonenzymatic antioxidant defense systems such as SOD,GPOD,CAT,and soluble protein.

  18. Occurrence of arbuscular mycorrhizas and dark septate endophytes in pteridophytes from a Patagonian rainforest, Argentina.

    Science.gov (United States)

    Fernández, Natalia Verónica; Messuti, María Inés; Fontenla, Sonia Beatriz

    2013-06-01

    Arbuscular mycorrhizas (AM) are one of the most widespread types of symbiotic associations. Pteridophytes occupy an important position in the evolution of vascular plants. However, their mycorrhizal state remains poorly understood. The aim of this work was to describe the general mycorrhizal status and the occurrence of dark septate endophytes (DSE) in the pteridophytic flora of a Valdivian temperate forest in Patagonia, Argentina. First, the roots of nine terrestrial species representing six families were examined, and this information was then compared with other surveys concerning the occurrence of AM in other pteridophytic species within the same Valdivian temperate forest. AM were recorded in 98.6% of the samples analyzed in this work and all of them corresponded to the Paris-type morphology. DSEs were also present within the roots of all terrestrial species. A comparison to published results in other ferns and lycophytes that have been studied in this Valdivian temperate forest (161 sporophytes, 21 species and 10 families) was made. Clear differences in colonization patterns between eusporangiate/leptosporangiate and epiphytic/terrestrial species became evident and are discussed.

  19. Effects of Arbuscular Mycorrhiza on Plant Chemistry and the Development and Behavior of a Generalist Herbivore.

    Science.gov (United States)

    Tomczak, Viktoria V; Schweiger, Rabea; Müller, Caroline

    2016-12-01

    Arbuscular mycorrhiza (AM) formed between plants and AM fungi (AMF) can alter host plant quality and thus influence plant-herbivore interactions. While AM is known to affect the development of generalist chewing-biting herbivores, AM-mediated impacts on insect behavior have been neglected until now. In this study, the effects of Rhizophagus irregularis, a generalist AMF, on phenotypic and leaf metabolic traits of Plantago major plants were investigated. Further, the influence of AM-mediated host plant modifications on the development and on seven behavioral traits of larvae of the generalist Mamestra brassicae were recorded. Tests were carried out in the third (L3) and fourth (L4) larval instar, respectively. While shoot water content, specific leaf area, and foliar concentrations of the secondary metabolite aucubin were higher in AM-treated compared to non-mycorrhized (NM) plants, lower concentrations of the primary metabolites citric acid and isocitric acid were found in leaves of AM plants. Larvae reared on AM plants gained a higher body mass and tended to develop faster than individuals reared on NM plants. However, plant treatment had no significant effect on any of the behavioral traits. Instead, differences between larvae of different ages were detected in several behavioral features, with L4 being less active and less bold than L3 larvae. The results demonstrate that AM-induced modifications of host plant quality influence larval development, whereas the behavioral phenotype seems to be more fixed at least under the tested conditions.

  20. 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.

  1. Arbuscular mycorrhiza maintains nodule function during external NH4+ supply in Phaseolus vulgaris (L.).

    Science.gov (United States)

    Mortimer, Peter E; Pérez-Fernández, Maria A; Valentine, Alex J

    2012-04-01

    The synergistic benefits of the dual inoculation of legumes with nodule bacteria and arbuscular mycorrhizae (AM) are well established, but the effect of an external NH(4)(+) supply on this tripartite relationship is less clear. This effect of NH(4)(+) supply was investigated with regards to the growth and function of the legume host and both symbionts. Nodulated Phaseolus vulgaris seedlings with and without AM, were grown in a sand medium with either 0 N, 1 mM or 3 mM NH(4)(+). Plants were harvested at 30 days after emergence and measurements were taken for biomass, N(2) fixation, photosynthesis, asparagine concentration, construction costs and N nutrition. The addition of NH(4)(+) led to a decline in the percentage AM colonization and nodule dry weights, although AM colonization was affected to a lesser extent. NH(4)(+) supply also resulted in a decrease in the reliance on biological nitrogen fixation (BNF); however, the AM roots maintained higher levels of NH(4)(+) uptake than their non-AM counterparts. Furthermore, the non-AM plants had a higher production of asparagine than the AM plants. The inhibitory effects of NH(4)(+) on nodule function can be reduced by the presence of AM at moderate levels of NH(4)(+) (1 mM), via improving nodule growth or relieving the asparagine-induced inhibition of BNF. © Springer-Verlag 2011

  2. Terpenoids in plant and arbuscular mycorrhiza-reinforced defence against herbivorous insects.

    Science.gov (United States)

    Sharma, Esha; Anand, Garima; Kapoor, Rupam

    2017-03-01

    Plants, though sessile, employ various strategies to defend themselves against herbivorous insects and convey signals of an impending herbivore attack to other plant(s). Strategies include the production of volatiles that include terpenoids and the formation of symbiotic associations with fungi, such as arbuscular mycorrhiza (AM). This constitutes a two-pronged above-ground/below-ground attack-defence strategy against insect herbivores. Terpenoids represent an important constituent of herbivore-induced plant volatiles that deter herbivores and/or attract their predators. Terpenoids serve as airborne signals that can induce defence responses in systemic undamaged parts of the plant and also prime defence responses in neighbouring plants. Colonization of roots by AM fungi is known to influence secondary metabolism in plants; this includes alteration of the concentration and composition of terpenoids, which can boost both direct and indirect plant defence against herbivorous insects. Enhanced nutrient uptake facilitated by AM, changes in plant morphology and physiology and increased transcription levels of certain genes involved in the terpenoid biosynthesis pathway result in alterations in plant terpenoid profiles. The common mycorrhizal networks of external hyphae have added a dimension to the two-pronged plant defence strategy. These act as conduits to transfer defence signals and terpenoids. Improved understanding of the roles of terpenoids in plant and AM defences against herbivory and of interplant signalling in natural communities has significant implications for sustainable management of pests in agricultural ecosystems.

  3. The Arbuscular Mycorrhiza Rhizophagus intraradices Reduces the Negative Effects of Arsenic on Soybean Plants

    Directory of Open Access Journals (Sweden)

    Federico Spagnoletti

    2015-05-01

    Full Text Available Arsenic (As in soils causes several detrimental effects, including death. Arsenic toxicity in soybean plants (Glycine max L. has been little studied. Arbuscular mycorrhiza (AM increase the tolerance of host plants to abiotic stress, like As. We investigated the effects of AM fungi on soybean grown in As-contaminated soils. A pot experiment was carried out in a glasshouse, at random with five replications. We applied three levels of As (0, 25, and 50 mg As kg−1, inoculated and non-inoculated with the AM fungus Rhizophagus intraradices (N.C. Schenck & G.S. Sm. C. Walker & A. Schüßler. Plant parameters and mycorrhizal colonization were measured. Arsenic in the substrate, roots, and leaves was quantified. Arsenic negatively affected the AM percentage of spore germination and hyphal length. As also affected soybean plants negatively: an extreme treatment caused a reduction of more than 77.47% in aerial biomass, 68.19% in plant height, 78.35% in number of leaves, and 44.96% reduction in root length, and delayed the phenological evolution. Mycorrhizal inoculation improved all of these parameters, and decreased plant As accumulation (from 7.8 mg As kg−1 to 6.0 mg As kg−1. AM inoculation showed potential to reduce As toxicity in contaminated areas. The AM fungi decreased As concentration in plants following different ways: dilution effect, less As intake by roots, and improving soybean tolerance to As.

  4. Multiple exocytotic markers accumulate at the sites of perifungal membrane biogenesis in arbuscular mycorrhizas.

    Science.gov (United States)

    Genre, A; Ivanov, S; Fendrych, M; Faccio, A; Zársky, V; Bisseling, T; Bonfante, P

    2012-01-01

    Arbuscular mycorrhizas (AMs) are symbiotic interactions established within the roots of most plants by soil fungi belonging to the Glomeromycota. The extensive accommodation of the fungus in the root tissues largely takes place intracellularly, within a specialized interface compartment surrounded by the so-called perifungal membrane, an extension of the host plasmalemma. By combining live confocal imaging of green fluorescent protein (GFP)-tagged proteins and transmission electron microscopy (TEM), we have investigated the mechanisms leading to the biogenesis of this membrane. Our results show that pre-penetration responses and symbiotic interface construction are associated with extensive membrane dynamics. They involve the main components of the exocytotic machinery, with a major participation of the Golgi apparatus, as revealed by both TEM and in vivo GFP imaging. The labeling of known exocytosis markers, such as v-SNARE proteins of the VAMP72 family and the EXO84b subunit of the exocyst complex, allowed live imaging of the cell components involved in perifungal membrane construction, clarifying how this takes place ahead of the growing intracellular hypha. Lastly, our novel data are used to illustrate a model of membrane dynamics within the pre-penetration apparatus during AM fungal penetration.

  5. Establishment of Desmoncus orthacanthos Martius (Arecaceae): effect of inoculation with arbuscular mycorrhizae.

    Science.gov (United States)

    Ramos-Zapata, José A; Orellana, Roger; Allen, Edith B

    2006-03-01

    Inoculation with arbuscular mycorrhizal (AM) fungi has often promoted increased growth of plants but very little work has been done in the tropics to evaluate the effects of inoculation on the establishment and development of seedlings in forests. Desmoncus orthacanthos Martius is a scandent palm present both in early and late succession, and consequently can be used in restoration processes. A test was conducted to determine the effect of AM on the establishment of Desmoncus orthacanthos in tropical forest in the Yucatan Peninsula, Mexico. Thirty inoculated and 30 non-inoculated seedlings were introduced in two sites of different successional age, a mature forest and an eight-year old abandoned cornfield (acahual). Survival and growth parameters were evaluated after 12 months. Leaf area and phosphorus, but not height, were greater in inoculated than non-inoculated plants in the forest but not in the acahual. However, mycorrhizae had a clear effect on plant survival in both sites, with a threefold increase in survival of inoculated compared with non-inoculated plants bassed on an odds ratio. The results suggest that inoculation will be important to increase the establishment of this commercially important palm.

  6. Characterization of expressed genes in the establishment of arbuscular mycorrhiza between Amorpha fruticosa and Glomus mosseae

    Institute of Scientific and Technical Information of China (English)

    Fuqiang Song; Jize Li; Xingxing Zhang

    2014-01-01

    Arbuscular mycorrhiza (AM) formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR (DDRT-PCR). The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag (ESTs) sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi.

  7. Temporal and spatial variation of arbuscular mycorrhizas in salt marsh plants of the Tagus estuary (Portugal).

    Science.gov (United States)

    Carvalho, L M; Caçador, I; Martins-Loução, M

    2001-12-01

    The factors which may influence temporal and spatial variation in plant arbuscular mycorrhizal (AM) colonization and propagule occurrence were evaluated in a Portuguese salt marsh poor in plant diversity. Two distinct sites were studied: a more-flooded (low marsh) and a less-flooded zone (high marsh). AM root colonization, AM fungal spore number and inoculum potential, soil edaphic parameters and tidal flooding time periods were analysed. Levels of AM colonization were considerable in Aster tripolium and Inula crithmoides but very low in Puccinellia maritima and non-existent in Spartina maritima, Halimione portulacoides, Arthrocnemum fruticosum and Arthrocnemum perenne. Fungal diversity was very low, with Glomus geosporum dominant at both marsh zones. Colonization showed no spatial variation within marsh zones but temporal variation was observed in the high marsh, dependent on plant phenological phases. In the low marsh, no significantly seasonal variation was observed. Apparently, plant phenological events were diluted by stressful conditions (e.g. flooding, salinity). Spore density was significantly different between marsh zones and showed temporal variation in both zones. This study showed that distribution of mycorrhizas in salt marsh is more dependent on host plant species than on environmental stresses.

  8. 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.

  9. Arbuscular mycorrhizae formed by Penicillium pinophilum improve the growth, nutrient uptake and photosynthesis of strawberry with two inoculum-types.

    Science.gov (United States)

    Fan, Yongqiang; Luan, Yushi; An, Lijia; Yu, Kun

    2008-08-01

    Penicillium pinophilum was isolated from the soil in a commercial strawberry field. The strain readily formed arbuscular mycorrhizae (AM) with the roots of strawberry 'Zoji' (Fragaria x ananassa Duch. CV.) when plants were inoculated with either fresh cultured hyphae or root/soil mixtures. Fresh hyphae, however, resulted in higher amounts of colonization than root/soil inoculum. Compared with uninoculated strawberries, inoculation increased plant dry weight by 31%, as well as nitrogen content (47%), phosphorus content (57%), and photosynthetic rate (71%). AM inoculation also shortened the blossom and ripening date by 3 and 4 days, respectively. This is the first report of a P. pinophilum strain resulting in mycorrhiza with strawberry roots. The significant advantages of this strain are that it is easy to culture and inoculation of plants results in significant growth benefits that may be useful in strawberry production.

  10. VA菌根在植物生态学研究中的意义%Importance of Vesicular Arbuscular Mycorrhiza in Plant Ecological Research.

    Institute of Scientific and Technical Information of China (English)

    赵之伟

    2001-01-01

    Vesicular arbuscular mycorrhiza is the symbiont of plant and Glomales fungus.This symbiont is a very popular biological phenomenon in the terrestrial ecosystem.Based on the popularity and the non-specificity between the symbiotic partners,the potential determinant roles of VA mycorrhizal fungi in the occur rence,succession and the structure of plant community,and the mechanisms of VA mycorrhiza in the maintenance of plant biodiversity,the stability and the pro ductivity of the ecosystem were discussed in this paper.The functional roles of VA mycorrhiza in the plant biodiversity conservation was also discussed.

  11. Effects of vesicular-arbuscular mycorrhizae on survival and growth of perennial grasses in lignite overburden in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Call, C.A.; Davies, F.T.

    1988-12-01

    Seedlings of sideoats grama (Bouteloua curtipendula), Indiangrass (Sorghastrum nutans), and kleingrass (Panicum coloratum) were inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi (Glomus fasciculatum and Gigaspora margarita) in a containerized system and transplanted into lignite overburden in the Post Oak Savannah region of Texas, U.S.A. After three growing seasons without cultural inputs, plants inoculated with VAM fungi had greater survival percentages, basal diameters, and above-ground biomass than noninoculated plants. Inoculated plants had higher levels of nitrogen and phosphorus in above-ground biomass than noninoculated plants. Root colonization percentages of inoculated plants remained fairly stable while noninoculated plants showed low levels of colonization over the 3-year study period. Vesicular-arbuscular mycorrhizae enhanced the survival and growth of the 3 grass species by making effective use of limited resources in the lignite overburden. 31 refs., 3 tabs.

  12. Occurrence of Arbuscular Mycorrhizas and Dark Septate Endophytes in Hydrophytes from Lakes and Streams in Southwest China

    Science.gov (United States)

    Kai, Wang; Zhiwei, Zhao

    2006-02-01

    In this study, the colonization of arbuscular mycorrhizas (AM) and dark septate endophytes (DSE) in 140 specimens of 32 hydrophytes collected from four lakes and four streams in southwest China were investigated. The arbuscular mycorrhizal fungi (AMF) and DSE colonization in these hydrophytes were rare. Typical AM structures were observed in one of the 25 hydrophytic species collected in lakes and six of the 17 species collected in streams.Spores of 10 identified AMF species and an unidentified Acaulospora sp. were isolated from the sediments. The identified AMF came from the four genera, Acaulospora, Gigaspora, Glomus and Scutellospora . Glomus and G. mosseae were the dominant genus and species respectively in these aquatic environments.The presence of DSE in hydrophytes was recorded for the first time. DSE occurred in one of the 25 hydrophyte species collected in lakes and three of the 17 species collected in streams.

  13. Arbuscular mycorrhiza symbiosis induces a major transcriptional reprogramming of the potato SWEET sugar transporter family

    Directory of Open Access Journals (Sweden)

    Jasmin eManck-Götzenberger

    2016-04-01

    Full Text Available Biotrophic microbes feeding on plants must obtain carbon from their hosts without killing the cells. The symbiotic arbuscular mycorrhizal (AM fungi colonizing plant roots do so by inducing major transcriptional changes in the host that ultimately also reprogram the whole carbon partitioning of the plant. AM fungi obtain carbohydrates from the root cortex apoplast, in particular from the periarbuscular space that surrounds arbuscules. However, the mechanisms by which cortical cells export sugars into the apoplast for fungal nutrition are unknown. Recently a novel type of sugar transporter, the SWEET, able to perform not only uptake but also efflux from cells was identified. Plant SWEETs have been shown to be involved in the feeding of pathogenic microbes and are, therefore, good candidates to play a similar role in symbiotic associations. Here we have carried out the first phylogenetic and expression analyses of the potato SWEET family and investigated its role during mycorrhiza symbiosis. The potato genome contains 35 SWEETs that cluster into the same four clades defined in Arabidopsis. Colonization of potato roots by the AM fungus Rhizophagus irregularis imposes major transcriptional rewiring of the SWEET family involving, only in roots, changes in 22 of the 35 members. None of the SWEETs showed mycorrhiza-exclusive induction and most of the twelve induced genes belong to the putative hexose transporters of clade I and II, while only two are putative sucrose transporters from clade III. In contrast, most of the repressed transcripts (10 corresponded to clade III SWEETs. Promoter-reporter assays for three of the induced genes, each from one cluster, showed re-localization of expression to arbuscule-containing cells, supporting a role for SWEETs in the supply of sugars at biotrophic interfaces. The complex transcriptional regulation of SWEETs in roots in response to AM fungal colonization supports a model in which symplastic sucrose in cortical

  14. 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...

  15. 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

  16. A comparison of the development and metabolic activity of mycorrhizas formed by arbuscular mycorrhizal fungi from different genera on two tropical forage legumes

    NARCIS (Netherlands)

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

    1998-01-01

    Two glasshouse experiments were done to assess the development and metabolic activity of mycorrhizas formed by isolates of arbuscular mycorrhizal fungi (AMF) from three different genera, Acaulospora, Gigaspora and Glomus on either Pueraria phaseoloides L. or Desmodium ovalifolium L. plants. The seco

  17. [Effect of Arbuscular Mycorrhiza (AM) on Tolerance of Cattail to Cd Stress in Aquatic Environment].

    Science.gov (United States)

    Luo, Peng-cheng; Li, Hang; Wang, Shu-guang

    2016-02-15

    Hygrophytes are planted more and more in landscaping and greening in many cities, but they often encounter threat from environmental pollution. Arbuscular mycorrhiza ( AM ) have been confirmed to enhance the tolerance of terrestrial plants to environmental pollution in many previous studies, but it is unclear how they affect hygrophytes. In the present study, a hydroponic culture experiment was carried out to investigate the effects of AM fungi (Glomus etunicatum) inoculation on the tolerance of cattail (Typha latifolia) to different concentrations Cd2+ (0, 2.5, 5.0 mg x L(-1)). The aim was to provide reference for evaluating whether mycorrhizal technology can be used to enhance the tolerance of hygrophytes to environmental pollution. The results showed that symbiotic association was well established between AM fungi and cattail roots, and the mycorrhizal colonization rates (MCR) were beyond 30%. However, MCR presented downward trend one month after mycorrhizal cattails were transported to solution, and the maximal decrease was 25.5% (P < 0.05). AM increased pigment concentrations and peroxidase (POD) activity in cattail leaves, and also increased roots radial oxygen loss. However, AM only produced significant effect on increase of fresh weight in 5 mg x L(-1) Cd2+ solution. Although plant growth was inhibited by 5 mg x L(-1) Cd2+ and MCR was lower, AM increased Cd uptake of cattail at the two Cd2+ levels, and the maximal increments were 40.24% and 56.52% in aboveground and underground parts, respectively. This study indicates that AM has potential to enhance the tolerance of hygrophytes to environmental pollution and might be used to remedy heavy metal pollution.

  18. Can corn plants inoculated with arbuscular mycorrhiza fungi affect soil clay assemblage?

    Science.gov (United States)

    Adamo, P.; Cozzolino, V.; Di Meo, V.; Velde, B.

    2012-04-01

    Plants can extract K from exchangeable and non-exchangeable sites in the soil clay mineral structures. The latter, known as fixed K, is usually seen as an illite layer, i.e. an anhydrous K layer that forms a 1.0 nm structural layer unit as seen by X-ray diffraction. Nutrient availability can be enhanced in the root zone by arbuscular mycorrhiza fungi. In this study, the effects of non-inoculated and Glomus intraradices inoculated corn plant growth under different experimental conditions on soil K-bearing clay minerals were identified. The soil, a Vertic Xerofluvent, was planted in corn in a 2008-2010 randomized field experiment. Bulk and rhizosphere soil sampling was carried out from May to September 2010 from fertilized plots (N200P90K160 and N200P0K160) with and without plants. According to XRD analysis, three major K-bearing minerals were present in soil: smectite-rich mixed layer mineral, illite-rich mixed layer mineral and illite. Results at 40DAS indicate extraction of K from clay minerals by plant uptake, whereas at 130DAS much of the nutrient seems to be returned to the soil. There is an apparent difference between bulk and rhizophere clays. The XRD patterns are not unequivocally affected by Glomus inoculation. There are observable changes in clay mineralogy in fallow unfertilized compared with fertilized soil. In the studied soil, the illite rich mixed-layer minerals seem to be the source of K absorbed by plants, while illite acts as sink of K released from the plant-microorganisms system at the end of the growing season and as source for the following crop.

  19. Nutrient limitation drives response of Calamagrostis epigejos to arbuscular mycorrhiza in primary succession.

    Science.gov (United States)

    Rydlová, Jana; Püschel, David; Dostálová, Magdalena; Janoušková, Martina; Frouz, Jan

    2016-10-01

    Little is known about the functioning of arbuscular mycorrhizal (AM) symbiosis over the course of primary succession, where soil, host plants, and AM fungal communities all undergo significant changes. Over the course of succession at the studied post-mining site, plant cover changes from an herbaceous community to the closed canopy of a deciduous forest. Calamagrostis epigejos (Poaceae) is a common denominator at all stages, and it dominates among AM host species. Its growth response to AM fungi was studied at four distinctive stages of natural succession: 12, 20, 30, and 50 years of age, each represented by three spatially separated sites. Soils obtained from all 12 studied sites were γ-sterilized and used in a greenhouse experiment in which C. epigejos plants were (1) inoculated with a respective community of native AM fungi, (2) inoculated with reference AM fungal isolates from laboratory collection, or (3) cultivated without AM fungi. AM fungi strongly boosted plant growth during the first two stages but not during the latter two, where the effect was neutral or even negative. While plant phosphorus (P) uptake was generally increased by AM fungi, no contribution of mycorrhizae to nitrogen (N) uptake was recorded. Based on N:P in plant biomass, we related the turn from a positive to a neutral/negative effect of AM fungi on plant growth, observed along the chronosequence, to a shift in relative P and N availability. No functional differences were found between native and reference inocula, yet root colonization by the native AM fungi decreased relative to the reference inoculum in the later succession stages, thereby indicating shifts in the composition of AM fungal communities reflected in different functional characteristics of their members.

  20. The Petunia GRAS Transcription Factor ATA/RAM1 Regulates Symbiotic Gene Expression and Fungal Morphogenesis in Arbuscular Mycorrhiza1

    Science.gov (United States)

    Rich, Mélanie K.

    2015-01-01

    Arbuscular mycorrhiza (AM) is a mutual symbiosis that involves a complex symbiotic interface over which nutrients are exchanged between the plant host and the AM fungus. Dozens of genes in the host are required for the establishment and functioning of the interaction, among them nutrient transporters that mediate the uptake of mineral nutrients delivered by the fungal arbuscules. We have isolated in a genetic mutant screen a petunia (Petunia hybrida) GIBBERELLIC ACID INSENSITIVE, REPRESSOR of GIBBERELLIC ACID INSENSITIVE, and SCARECROW (GRAS)-type transcription factor, ATYPICAL ARBUSCULE (ATA), that acts as the central regulator of AM-related genes and is required for the morphogenesis of arbuscules. Forced mycorrhizal inoculations from neighboring wild-type plants revealed an additional role of ATA in restricting mycorrhizal colonization of the root meristem. The lack of ATA, which represents the ortholog of REQUIRED FOR ARBUSCULAR MYCORRHIZA1 in Medicago truncatula, renders the interaction completely ineffective, hence demonstrating the central role of AM-related genes for arbuscule development and function. PMID:25971550

  1. Antifungal genes expressed in transgenic pea (Pisum sativum L.) do not affect root colonization of arbuscular mycorrhizae fungi.

    Science.gov (United States)

    Kahlon, Jagroop Gill; Jacobsen, Hans-Jörg; Cahill, James F; Hall, Linda M

    2017-06-12

    Genetically modified crops have raised concerns about unintended consequences on non-target organisms including beneficial soil associates. Pea transformed with four antifungal genes 1-3 β glucanase, endochitinase, polygalacturonase-inhibiting proteins, and stilbene synthase is currently under field-testing for efficacy against fungal diseases in Canada. Transgenes had lower expression in the roots than leaves in greenhouse experiment. To determine the impact of disease-tolerant pea or gene products on colonization by non-target arbuscular mycorrhizae and nodulation by rhizobium, a field trial was established. Transgene insertion, as single gene or stacked genes, did not alter root colonization by arbuscular mycorrhiza fungus (AMF) or root nodulation by rhizobium inoculation in the field. We found no effect of transgenes on the plant growth and performance although, having a dual inoculant with both AMF and rhizobium yielded higher fresh weight shoot-to-root ratio in all the lines tested. This initial risk assessment of transgenic peas expressing antifungal genes showed no deleterious effect on non-target organisms.

  2. The Petunia GRAS Transcription Factor ATA/RAM1 Regulates Symbiotic Gene Expression and Fungal Morphogenesis in Arbuscular Mycorrhiza.

    Science.gov (United States)

    Rich, Mélanie K; Schorderet, Martine; Bapaume, Laure; Falquet, Laurent; Morel, Patrice; Vandenbussche, Michiel; Reinhardt, Didier

    2015-07-01

    Arbuscular mycorrhiza (AM) is a mutual symbiosis that involves a complex symbiotic interface over which nutrients are exchanged between the plant host and the AM fungus. Dozens of genes in the host are required for the establishment and functioning of the interaction, among them nutrient transporters that mediate the uptake of mineral nutrients delivered by the fungal arbuscules. We have isolated in a genetic mutant screen a petunia (Petunia hybrida) Gibberellic Acid Insensitive, Repressor of Gibberellic Acid Insensitive, and Scarecrow (GRAS)-type transcription factor, Atypical Arbuscule (ATA), that acts as the central regulator of AM-related genes and is required for the morphogenesis of arbuscules. Forced mycorrhizal inoculations from neighboring wild-type plants revealed an additional role of ATA in restricting mycorrhizal colonization of the root meristem. The lack of ATA, which represents the ortholog of Required For Arbuscular Mycorrhiza1 in Medicago truncatula, renders the interaction completely ineffective, hence demonstrating the central role of AM-related genes for arbuscule development and function. © 2015 American Society of Plant Biologists. All Rights Reserved.

  3. Influence of Arbuscular Mycorrhiza on Membrane Lipid Peroxidation and Soluble Sugar Content of Soybean under Salt Stress

    Directory of Open Access Journals (Sweden)

    Ali Moradi

    2015-01-01

    Full Text Available The influence of the arbuscular mycorrhizal (AM fungus, Glomus mosseae, on characteristics of growth, membrane lipid peroxidation and soluble sugar content in the shoots and roots of soybean (Glycine max plants was studied in pot culture under salt stress. The experiment was arranged as a factorial in Randomized Complete Block Design (RCBD with four replications in greenhouse of College of Agriculture, Tehran University, Iran. The plants inoculated with mycorrhiza had significantly greater shoot and root biomass than the nonmycorrhizal plants at all salinity levels. AM symbiosis decreased membrane relative permeability and malondialdehyde content in shoots and roots. The soluble sugar content in roots was higher in mycorrhizal than nonmycorrhizal plants, but there was no significant difference in soluble sugar content in shoots between mycorrhizal and nonmycorrhizal plants. The results indicate that the AM fungus is capable of alleviating the damage caused by salt stress on soybean plants by reducing membrane lipid peroxidation and increasing the accumulation of soluble sugar content. Consequently, arbuscular mycorrhiza formation highly enhanced the salinity tolerance of soybean plant, which increased host biomass and promoted plant growth.

  4. Cadmium accumulation and buffering of cadmium-induced stress by arbuscular mycorrhiza in three Pisum sativum L. genotypes.

    Science.gov (United States)

    Rivera-Becerril, Facundo; Calantzis, Catherine; Turnau, Katarzyna; Caussanel, Jean-Pierre; Belimov, Andrei A; Gianinazzi, Silvio; Strasser, Reto J; Gianinazzi-Pearson, Vivienne

    2002-05-01

    The role of arbuscular mycorrhiza in reducing Cd stress was investigated in three genotypes of Pisum sativum L. (cv. Frisson, VIR4788, VIR7128), grown in soil/sand pot cultures in the presence and absence of 2-3 mg kg(-1) bioavailable Cd, and inoculated or not with the arbuscular mycorrhizal fungus Glomus intraradices. Shoot, root and pod biomass were decreased by Cd in non-mycorrhizal plants. The presence of mycorrhiza attenuated the negative effect of Cd so that shoot biomass and activity of photosystem II, based on chlorophyll a fluorescence, were not significantly different between mycorrhizal plants growing in the presence or absence of the heavy metal (HM). Total P concentrations were not significantly different between mycorrhizal and non-mycorrhizal plants treated with Cd. From 20-50-fold more Cd accumulated in roots than in shoots of Cd-treated plants, and overall levels were comparable to other metal-accumulating plants. Genetic variability in Cd accumulation existed between the pea genotypes. Concentration of the HM was lowest in roots of VIR4788 and in pods of VIR4788 and VIR7128. G. intraradices inoculation decreased Cd accumulation in roots and pods of cv. Frisson, whilst high concentrations were maintained in roots and pods of mycorrhizal VIR7128. Shoot concentrations of Cd increased in mycorrhizal cv. Frisson and VIR4788. Sequestration of Cd in root cell walls and/or cytoplasm, measured by EDS/SEM, was comparable between non-mycorrhizal pea genotypes but considerably decreased in mycorrhizal cv. Frisson and VIR7128. Possible mechanisms for mycorrhiza buffering of Cd-induced stress in the pea genotypes are discussed.

  5. Arum- and Paris-type arbuscular mycorrhizas in a mixed pine forest on sand dune soil in Niigata Prefecture, central Honshu, Japan.

    Science.gov (United States)

    Matekwor Ahulu, Evelyn; Nakata, Makoto; Nonaka, Masanori

    2005-03-01

    Arbuscular mycorrhizas (AM) are the most widespread mycorrhiza in nature and form two morphologies, Arum- and Paris-type. The determining factors defining the two different morphologies are not well understood. In this study, the distribution of Arum- and Paris-type AM was determined in a mixed pine forest. A total of 35 plant species belonging to 20 families and 32 genera were identified and examined for AM colonization and morphological types. AM morphological types in 14 families were confirmed as follows: Arum-type in Rosaceae, Oleaceae, Lauraceae, Vitaceae and Compositae, Paris-type in Aquifoliaceae, Ulmaceae, Araliaceae, Theaceae, Magnoliaceae, Rubiaceae and Dioscoraceae, and both and/or intermediate types in Caprifoliaceae and Gramineae. Plant families whose AM morphological status was previously unknown were clarified as follows: Polygonaceae and Commelinaceae showed Arum-type morphology; Celastraceae, Menispermaceae and Elaeagnaceae had typical Paris-type morphology. The proportion of Arum-type to Paris-type species decreased in the following order: annuals > perennials > deciduous species > evergreen species, and pioneer group > early successional group > late successional group. Evergreen plants had a higher tendency to form Paris-type AM than annuals, perennials and deciduous plants. The results indicate that environmental changes, such as shade during plant succession, control the distribution of plant growth forms in mixed pine forest and may also play a part in the distribution of Arum- and Paris-type morphology. The identity of the plant seems to strongly influence AM morphology, though control by the fungal genome cannot be ruled out.

  6. Effect of arbuscular mycorrhiza fungi and organic fertilizers on yield and nutrients uptake of two wheat cultivars

    Directory of Open Access Journals (Sweden)

    B. Kermanizadeh

    2016-09-01

    Full Text Available This research was conducted in order to evaluate the direct effects of organic and biofertilizers on yield of two native wheat cultivars (Bolani and cross-Bolani in Sistan area. The experiment was performed as a factorial, based on a completely randomized design with three replications, in Research Greenhouse of University of Zabol. In this study, fertilizer factor at 8 levels [Vermicompost (F1, vermicompost + compost (F2, vermicompost + mycorrhiza (F3, vermicompost + mycorrhiza + compost (F4, compost (F5, compost + mycorrhiza (F6, mycorrhiza (F7 and control (no fertilizer application, F8] and two wheat cultivars [Bolani (C1 and cross-Bolani (C2] were considered. Results showed that the highest grain yield (1.13 g/pot was obtained from combination of mycorrhiza and cross-Bolani treatments (F7C2. Combined treatments of compost + mycorrhiza and cross-Bolani (F6C2 and vermicompost + compost and cross-Bolani (F2C2 were more suitable for nitrogen uptake. The highest percentage of protein (10.27% was resulted from F6C2 and F2C2 treatment. Overall, combined treatments of F6C2 and F2C2 seem appropriate for Bolani and cross-Bolani wheat cultivars.

  7. Micorrizas arbusculares y endófitos septados oscuros en Gentianaceae nativas de la Argentina Arbuscular mycorrhizas and dark septates endophytes in native Gentianaceae from Argentina

    Directory of Open Access Journals (Sweden)

    Leonardo A. Salvarredi

    2010-12-01

    Full Text Available Se estudió la colonización de raíces por simbiontes fúngicos en cinco especies de Gentianaceae nativas distribuidas en distintos ambientes de la Argentina, cuatro pertenecientes a Gentianella y una a Gentiana. Se observaron estructuras micorrícicas arbusculares pertenecientes al tipo Paris (hifas y circunvoluciones intracelulares y endófitos septados oscuros (SO (hifas y microesclerocios. Tres de las especies estudiadas se asociaron a micorrizas arbusculares (MA y SO, una sólo a SO y otra sólo a MA. La colonización radical por SO (hifas y microesclerocios y la colonización hifal MA difirieron con el hospedante. Este es el primer reporte de colonización por MA y SO en Gentianella helianthemoides, G. magellanica, G. parviflora y Gentiana prostrata. Se discute la influencia del hospedante y del ambiente en la colonización por MA y SO.The roots of five native species of Gentianaceae distributed in different environments of Argentina, four belonging to Gentianella and one to Gentiana, were studied for fungal symbionts colonization. Arbuscular mycorrhizal structures belonging to Paris type (intracellular hyphae and coils and dark septates endophytes (DS (hyphae microesclerotia were observed. Three of the species studied were associated to both arbuscular mycorrhizas (AM and DS, only one to DS and the other only to AM. Root colonization by DS (hyphae and microesclerotia and AM hyphal colonization were host dependent. This is the first report of AM and DS colonization for Gentianella helianthemoides, G. magellanica, G. parviflora and Gentiana prostrata. Host and environmental influence on AM and DS colonization is discussed.

  8. Observations on arbuscular mycorrhiza associated with important edible tuberous plants grown in wet evergreen forest in Assam, India

    Directory of Open Access Journals (Sweden)

    RAJA RISHI

    2013-10-01

    Full Text Available Kumar R, Tapwal A, Pandey S, Rishi R, Borah D. 2013. Observations on arbuscular mycorrhiza associated with important edible tuberous plants grown in wet evergreen forest in Assam, India. Biodiversitas 14: 67-72. Non-timber forest products constitute an important source of livelihood for rural households from forest fringe communities across the world. Utilization of wild edible tuber plants is an integral component of their culture. Mycorrhizal associations influence the establishment and production of tuber plants under field conditions.The aim of present study is to explore the diversity and arbuscular mycorrhizal (AMF colonization of wild edible tuber plants grown in wet evergreen forest of Assam, India. A survey was conducted in 2009-10 in Sunaikuchi, Khulahat, and Bura Mayong reserved forest of Morigaon district of Assam to determine the AMF spore population in rhizosphere soils and root colonization of 14 tuberous edible plants belonging to five families. The results revealed AMF colonization of all selected species in all seasons. The percent colonization and spore count was less in summer, moderate in winter and highest in rainy season. Seventeen species of arbuscular mycorrhizal fungi were recorded in four genera viz. Acaulospora (7 species, Glomus (5 species, Sclerocystis (3 species and Gigaspora (2 species.

  9. 柑橘丛枝菌根的研究新进展%New Advances in the Research of Arbuscular Mycorrhizas in Citrus

    Institute of Scientific and Technical Information of China (English)

    吴强盛; 邹英宁

    2014-01-01

    Citrus plants possess less or no root hairs in the fields and thus highly depend on arbuscular mycorrhizas to replace the root hair for nutrient uptake from soil .Therefore,arbuscular mycorrhizas in citrus have been widely concerned .This paper summarizes the new advances in the research of morphology ,fungal re-sources in rhizosphere ,physiology and molecular studies of arbuscular my corrhizas in citrus ,and factors impac-ting mycorrhizal functionings .It clarifies the physiological functions of arbuscular mycorrhizas in terms of plant growth ,nutrient uptake and adverse tolerance .%田间栽培的柑橘根毛少甚至无,高度依赖丛枝菌根替代根毛吸收养分,因而柑橘丛枝菌根的研究被广泛关注。本文综述了近20年国内外柑橘丛枝菌根的形态特征、根际丛枝菌根真菌的资源、丛枝菌根的生理和分子研究以及菌根功能的影响因子的最新进展,重点通过植株生长、营养吸收和抗逆性阐明丛枝菌根的生理功能。

  10. Micorrizas arbusculares en plantines de Alnus acuminata (Betulaceae inoculados con Glomus intraradices (Glomaceae Arbuscular mycorrhizas in Alnus acuminata (Betulaceae seedlings inoculated with Glomus intraradices (Glomaceae

    Directory of Open Access Journals (Sweden)

    Alejandra Becerra

    Full Text Available En este trabajo se cita y describe por primera vez la asociación de Alnus acuminata Kunth «aliso del cerro» con el hongo formador de micorrizas arbusculares (MA Glomus intraradices Schenk & Smith. En un bioensayo en invernadero, se inocularon plantines de A. acuminata con fragmentos radicales de Medicago sativa L. colonizados por G. intraradices . Se describe la colonización MA y el tipo anatómico Arum . Se establece la funcionalidad de la simbiosis por la presencia de arbúsculos en las células corticales de la raíz.This work described for the first time the arbuscular mycorrhiza (AM development in A. acuminata Kunth «andean alder» with G. intraradices Schenk & Smith. Seedlings of A. acuminata were inoculated with root fragments of Medicago sativa L. colonized by G. intraradices in a greenhouse. The Arum -type and AM colonization are described in A. acuminata seedlings. The presence of arbuscules in A. acuminata cortical cells define a functional symbiosis.

  11. The role of flavonoids in the establishment of plant roots endosymbioses with arbuscular mycorrhiza fungi, rhizobia and Frankia bacteria.

    Science.gov (United States)

    Abdel-Lateif, Khalid; Bogusz, Didier; Hocher, Valérie

    2012-06-01

    Flavonoids are a group of secondary metabolites derived from the phenylpropanoid pathway. They are ubiquitous in the plant kingdom and have many diverse functions including key roles at different levels of root endosymbioses. While there is a lot of information on the role of particular flavonoids in the Rhizobium-legume symbiosis, yet their exact role during the establishment of arbuscular mycorrhiza and actinorhizal symbioses still remains unclear. Within the context of the latest data suggesting a common symbiotic signaling pathway for both plant-fungal and plant bacterial endosymbioses between legumes and actinorhiza-forming fagales, this mini-review highlights some of the recent studies on the three major types of root endosymbioses. Implication of the molecular knowledge of endosymbioses signaling and genetic manipulation of flavonoid biosynthetic pathway on the development of strategies for the transfer and optimization of nodulation are also discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

  13. The role of flavonoids in the establishment of plant roots endosymbioses with arbuscular mycorrhiza fungi, rhizobia and Frankia bacteria

    Science.gov (United States)

    Abdel-Lateif, Khalid; Bogusz, Didier; Hocher, Valérie

    2012-01-01

    Flavonoids are a group of secondary metabolites derived from the phenylpropanoid pathway. They are ubiquitous in the plant kingdom and have many diverse functions including key roles at different levels of root endosymbioses. While there is a lot of information on the role of particular flavonoids in the Rhizobium-legume symbiosis, yet their exact role during the establishment of arbuscular mycorrhiza and actinorhizal symbioses still remains unclear. Within the context of the latest data suggesting a common symbiotic signaling pathway for both plant-fungal and plant bacterial endosymbioses between legumes and actinorhiza-forming fagales, this mini-review highlights some of the recent studies on the three major types of root endosymbioses. Implication of the molecular knowledge of endosymbioses signaling and genetic manipulation of flavonoid biosynthetic pathway on the development of strategies for the transfer and optimization of nodulation are also discussed. PMID:22580697

  14. Effects of vesicular-arbuscular mycorrhizae on the drought resistance of wild jujube (Zizyphs spinosus Hu) seedlings

    Institute of Scientific and Technical Information of China (English)

    LU Jinying; LIU Min; MAO Yongmin; SHEN Lianying

    2007-01-01

    The current study explored the effects of vesicular-arbuscular mycorrhizae (VAM) inoculation on the growth and water requirement of pot-grown wild jujube (Zizyphs spinosus Hu).Three water regimes (20%,40% and 60% of soil water content) were conducted.The VAM inoculation could significantly increase plant growth (including plant height,leaf area,and fresh and dry mass),enhance relative leaf water content,photosynthetic rates,transpiration rates and stomatal conductance,and improve plant drought tolerance.The water consumption of the mycorrhizal plants producing 1 g of dry matter was 18.7%-26.6% lower than the consumption of non-mycorrhizal plants grown under the same soil water content conditions.

  15. Proline and Abscisic Acid Content in Droughted Corn Plant Inoculated with Azospirillum sp. and Arbuscular Mycorrhizae Fungi

    Directory of Open Access Journals (Sweden)

    NOVRI YOULA KANDOWANGKO

    2009-03-01

    Full Text Available Plants that undergo drought stress perform a physiological response such as accumulation of proline in the leaves and increased content abscisic acid. A research was conducted to study proline and abscisic acid (ABA content on drought-stressed corn plant with Azospirillum sp. and arbuscular mycorrhizae fungi (AMF inoculated at inceptisol soil from Bogor, West Java. The experiments were carried out in a green house from June up to September 2003, using a factorial randomized block design. In pot experiments, two factors were assigned, i.e. inoculation with Azospirillum (0, 0.50, 1.00, 1.50 ml/pot and inoculation with AMF Glomus manihotis (0, 12.50, 25.00, 37.50 g/pot. The plants were observed during tasseling up to seed filling periods. Results of experiments showed that the interaction between Azospirillum sp. and AMF was synergistically increased proline, however it decreased ABA.

  16. Arbuscular mycorrhizae of the palm Astrocaryum mexicanum in disturbed and undisturbed stands of a Mexican tropical forest.

    Science.gov (United States)

    Núñez-Castillo, O; Alvarez-Sánchez, F J

    2003-10-01

    Tropical forests are dynamic systems with extensive natural disturbance, gaps in the canopy being one of the most important types. Tree and branch fall are often the principal cause of natural disturbance. This research was done on adult individuals of a very abundant palm ( Astrocaryum mexicanum Liebm, Arecaceae), which is found in the understorey of the forest at Los Tuxtlas, Mexico. Percentages of colonization by arbuscular mycorrhizae were determined for individuals selected randomly from plots located both in gaps and under closed canopy. The highest percentages of total colonization, as well as those of hyphae and vesicles, were recorded for gaps. In forest with closed canopy, arbuscules had the highest percentages of colonization; on these sites the palm has been observed to grow less. The higher production of arbuscules may favour nutrient capture in this microenvironment, which is characterized by strong competition.

  17. SymGRASS: a database of sugarcane orthologous genes involved in arbuscular mycorrhiza and root nodule symbiosis.

    Science.gov (United States)

    Belarmino, Luis Carlos; Silva, Roberta Lane de Oliveira; Cavalcanti, Nina da Mota Soares; Krezdorn, Nicolas; Kido, Ederson Akio; Horres, Ralf; Winter, Peter; Kahl, Günter; Benko-Iseppon, Ana Maria

    2013-01-01

    The rationale for gathering information from plants procuring nitrogen through symbiotic interactions controlled by a common genetic program for a sustainable biofuel production is the high energy demanding application of synthetic nitrogen fertilizers. We curated sequence information publicly available for the biofuel plant sugarcane, performed an analysis of the common SYM pathway known to control symbiosis in other plants, and provide results, sequences and literature links as an online database. Sugarcane sequences and informations were downloaded from the nucEST database, cleaned and trimmed with seqclean, assembled with TGICL plus translating mapping method, and annotated. The annotation is based on BLAST searches against a local formatted plant Uniprot90 generated with CD-HIT for functional assignment, rpsBLAST to CDD database for conserved domain analysis, and BLAST search to sorghum's for Gene Ontology (GO) assignment. Gene expression was normalized according the Unigene standard, presented as ESTs/100 kb. Protein sequences known in the SYM pathway were used as queries to search the SymGRASS sequence database. Additionally, antimicrobial peptides described in the PhytAMP database served as queries to retrieve and generate expression profiles of these defense genes in the libraries compared to the libraries obtained under symbiotic interactions. We describe the SymGRASS, a database of sugarcane orthologous genes involved in arbuscular mycorrhiza (AM) and root nodule (RN) symbiosis. The database aggregates knowledge about sequences, tissues, organ, developmental stages and experimental conditions, and provides annotation and level of gene expression for sugarcane transcripts and SYM orthologous genes in sugarcane through a web interface. Several candidate genes were found for all nodes in the pathway, and interestingly a set of symbiosis specific genes was found. The knowledge integrated in SymGRASS may guide studies on molecular, cellular and physiological

  18. SymGRASS: a database of sugarcane orthologous genes involved in arbuscular mycorrhiza and root nodule symbiosis

    Science.gov (United States)

    2013-01-01

    Background The rationale for gathering information from plants procuring nitrogen through symbiotic interactions controlled by a common genetic program for a sustainable biofuel production is the high energy demanding application of synthetic nitrogen fertilizers. We curated sequence information publicly available for the biofuel plant sugarcane, performed an analysis of the common SYM pathway known to control symbiosis in other plants, and provide results, sequences and literature links as an online database. Methods Sugarcane sequences and informations were downloaded from the nucEST database, cleaned and trimmed with seqclean, assembled with TGICL plus translating mapping method, and annotated. The annotation is based on BLAST searches against a local formatted plant Uniprot90 generated with CD-HIT for functional assignment, rpsBLAST to CDD database for conserved domain analysis, and BLAST search to sorghum's for Gene Ontology (GO) assignment. Gene expression was normalized according the Unigene standard, presented as ESTs/100 kb. Protein sequences known in the SYM pathway were used as queries to search the SymGRASS sequence database. Additionally, antimicrobial peptides described in the PhytAMP database served as queries to retrieve and generate expression profiles of these defense genes in the libraries compared to the libraries obtained under symbiotic interactions. Results We describe the SymGRASS, a database of sugarcane orthologous genes involved in arbuscular mycorrhiza (AM) and root nodule (RN) symbiosis. The database aggregates knowledge about sequences, tissues, organ, developmental stages and experimental conditions, and provides annotation and level of gene expression for sugarcane transcripts and SYM orthologous genes in sugarcane through a web interface. Several candidate genes were found for all nodes in the pathway, and interestingly a set of symbiosis specific genes was found. Conclusions The knowledge integrated in SymGRASS may guide studies on

  19. Effect of Arbuscular Mycorrhiza on the Content of Nitrogen and Nitrogenous Matter in Amur Corktree Seedlings%丛枝菌根对黄檗氮素及含氮物质含量的影响

    Institute of Scientific and Technical Information of China (English)

    范继红; 高琼; 邹原东

    2012-01-01

    [目的]研究丛枝菌根对黄檗氮素及含氮物质含量的影响。[方法]通过盆栽试验,用丛枝菌根真菌接种黄檗一年生实生苗,研究丛枝菌根对黄檗(Phellodendron amurense Rupr.)氮素及含氮物质含量的影响。[结果]黄檗幼苗形成丛枝菌根后,增加了叶片氮素含量,接种G.mosseae的苗木叶片氮素含量比对照提高了1.28~1.60倍,光合能力增强。接种丛枝菌根菌后,显著提高了黄檗叶绿素含量及叶绿素a和b的比值,增强了黄檗光合作用的能力,叶绿素a含量提高了25%以上;同时,增加了植物体内吲哚乙酸的含量,增加比例在1.65~2.41倍之间;增强植物体内硝酸还原酶的活性,增加了可溶性蛋白含量,增加比例在1.67~2.49倍之间,增强了植物氮素代谢能力,促进植物生长,增强植物的次生代谢能力。[结论]该研究结果为丛枝菌根真菌在黄檗上的应用提供了理论依据。%[Objective] This study aimed to explore the effect of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in amur corktree(Phellodendron amurense Rupr.)seedlings. [Method] The annual seedlings of Phellodendron amurense Rupr. were inoculated with four arbuscular mycorrhiza fungi in a pot experiment to study the influences of arbuscular mycorrhiza on the content of nitrogen and nitrogenous matter in Phellodendron amurense Rupr. [Result] After inoculation with arbuscular mycorrhiza fungi, the Phellodendron amurense Rupr. seedlings developed arbuscular mycorrhiza, leading to an enhancement of photosynthetic capacity. The leaf nitrogen content of those inoculated with Glomus mosseae increased to 1.28- 1.60 times as compared with the control. The chlorophyll content and chlorophyll a/b ratio were also raised, with an increase over 25% of chlorophyll a content. In addition, IAA content in plants increased to 1.65-2.41 times; and nitrate reductase activity was also

  20. 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.

  1. Membrane-Mediated Decrease in Root Exudation Responsible for Phorphorus Inhibition of Vesicular-Arbuscular Mycorrhiza Formation

    Science.gov (United States)

    Graham, James H.; Leonard, Robert T.; Menge, John A.

    1981-01-01

    The mechanism responsible for phosphorus inhibition of vesicular-arbuscular mycorrhiza formation in sudangrass (Sorghum vulgare Pers.) was investigated in a phosphorus-deficient sandy soil (0.5 micrograms phosphorus per gram soil) amended with increasing levels of phosphorus as superphosphate (0, 28, 56, 228 micrograms per gram soil). The root phosphorus content of 4-week-old plants was correlated with the amount of phosphorus added to the soil. Root exudation of amino acids and reducing sugars was greater for plants grown in phosphorus-deficient soil than for those grown in the phosphorus-treated soils. The increase in exudation corresponded with changes in membrane permeability of phosphorus-deficient roots, as measured by K+ (86Rb) efflux, rather than with changes in root content of reducing sugars and amino acids. The roots of phosphorus-deficient plants inoculated at 4 weeks with Glomus fasciculatus were 88% infected after 9 weeks as compared to less than 25% infection in phosphorus-sufficient roots; these differences were correlated with root exudation at the time of inoculation. For plants grown in phosphorus-deficient soil, infection by vesicular-arbuscular mycorrhizae increased root phosphorus which resulted in a decrease in root membrane permeability and exudation compared to nonmycorrhizal plants. It is proposed that, under low phosphorus nutrition, increased root membrane permeability leads to net loss of metabolites at sufficient levels to sustain the germination and growth of the mycorrhizal fungus during pre- and postinfection. Subsequently, mycorrhizal infection leads to improvement of root phosphorus nutrition and a reduction in membrane-mediated loss of root metabolites. PMID:16661955

  2. Herbivory and arbuscular mycorrhiza in natural populations of Datura stramonium L.: correlation with the availability of nutrients in the soil

    Directory of Open Access Journals (Sweden)

    Ana Aguilar-Chama

    2016-03-01

    Full Text Available Trophic interactions impose important costs to their host plants, affecting patterns of resource allocation. The relationship between host and consumers is also influenced by the availability of resources, e. g., soil nutrients. In this study, we explored the relationship among mycorrhiza-plant-herbivore in natural populations of Datura stramonium and their correlation with the content of phosphorus, nitrogen and carbon in the soil. We estimated the vegetative and reproductive biomass of plants, the arbuscular mycorrhizal colonization and the level of herbivory in populations of D. stramonium. The local abundance of D. stramonium was negatively related to the content of phosphorus in the soil. In contrast, soil carbon concentration affected positively the vegetative and reproductive mass of D. stramonium, although it was negatively correlated with the specific leaf area (SLA. Of the trophic interactions only herbivory was significantly correlated with the SLA and no relationship was detected between the two interaction types. The lack of significant response of mycorrhizae to the soil nutrients concentration, plant performance, and herbivory may result from the stochasticity in the availability of mycorrhizal inoculum (identity and abundance in the populations studied.

  3. Influence of arbuscular mycorrhiza on lipid peroxidation and antioxidant enzyme activity of maize plants under temperature stress.

    Science.gov (United States)

    Zhu, Xiancan; Song, Fengbin; Xu, Hongwen

    2010-06-01

    The influence of the arbuscular mycorrhizal (AM) fungus, Glomus etunicatum, on characteristics of growth, membrane lipid peroxidation, osmotic adjustment, and activity of antioxidant enzymes in leaves and roots of maize (Zea mays L.) plants was studied in pot culture under temperature stress. The maize plants were placed in a sand and soil mixture under normal temperature for 6 weeks and then exposed to five different temperature treatments (5 degrees C, 15 degrees C, 25 degrees C, 35 degrees C, and 40 degrees C) for 1 week. AM symbiosis decreased membrane relative permeability and malondialdehyde content in leaves and roots. The contents of soluble sugar content and proline in roots were higher, but leaf proline content was lower in mycorrhizal than nonmycorrhizal plants. AM colonization increased the activities of superoxide dismutase, catalase, and peroxidase in leaves and roots. The results indicate that the AM fungus is capable of alleviating the damage caused by temperature stress on maize plants by reducing membrane lipid peroxidation and membrane permeability and increasing the accumulation of osmotic adjustment compounds and antioxidant enzyme activity. Consequently, arbuscular mycorrhiza formation highly enhanced the extreme temperature tolerance of maize plant, which increased host biomass and promoted plant growth.

  4. Artificial climate warming positively affects arbuscular mycorrhizae but decreases soil aggregate water stability in an annual grassland

    Energy Technology Data Exchange (ETDEWEB)

    Rillig, M.C.; Wright, S.F.; Shaw, M.R.; Field, C.B.

    2002-04-01

    Despite the importance of arbuscular mycorrhizae to the functioning of terrestrial ecosystems (e.g. nutrient uptake, soil aggregation), and the increasing evidence of global warming, responses of arbuscular mycorrhizal fungi (AMF) to climate warming are poorly understood. In a field experiment using infrared heaters, we found effects of warming on AMF after one growing season in an annual grassland, in the absence of any effects on measured root parameters (weight, length, average diameter). AMF soil hyphal length was increased by over 40% in the warmed plots, accompanied by a strong trend for AMF root colonization increase. In the following year, root weight was again not significantly changed, and AMF root colonization increased significantly in the warmed plots. Concentration of the soil protein glomalin, a glycoprotein produced by AMF hyphae with importance in soil aggregation, was decreased in the warmed plots. Soil aggregate water stability, measured for five diameter size classes, was also decreased significantly. In the following year, soil aggregate weight in two size classes was decreased significantly, but the effect size was very small. These results indicate that ecosystem warming may have stimulated carbon allocation to AMF. Other factors either influenced glomalin decomposition or production, hence influencing the role of these symbionts in soil aggregation. The observed small changes in soil aggregation, if widespread among terrestrial ecosystems, could have important consequences for soil carbon storage and erosion in a warmed climate, especially if there are cumulative effects of warming. (au)

  5. The influence of arbuscular mycorrhizae and light on Wisconsin (USA) sand savanna understories 1. Plant community composition.

    Science.gov (United States)

    Landis, Frank C; Gargas, Andrea; Givnish, Thomas J

    2005-11-01

    To explain the complex community composition found in Wisconsin (USA) oak savannas, we investigated potentially interacting effects of light gradients and arbuscular mycorrhizal fungi (AMF) on community composition in the greenhouse, using a fully randomized block experimental design. We used plant species, soil, and AMF from a remnant sand savanna in setting up the experiment, using two light and five AMF treatments. Eleven plant species were seeded into 80 microcosms, and they were grown together for 20 weeks. Plant numbers and biomass were measured, and Simpson's index was calculated for both. Data were analyzed using ANOVA and nonparametric ANOVA. We found significant light effects on biomass and on numbers of four species. There were no treatment effects on Simpson's index, and only Schizachyrium numbers showed a significant AMF effect. These findings are consistent with results from other studies of the sand savanna, and, collectively, these data suggest that plant community composition in this species-rich savanna is not strongly influenced by arbuscular mycorrhizae. This is a novel finding with important implications for understanding interactions between plant and AMF diversity in wild communities.

  6. Arbuscular mycorrhiza of Deschampsia cespitosa (Poaceae at different soil depths in highly metal-contaminated site in southern Poland

    Directory of Open Access Journals (Sweden)

    Ewa Gucwa-Przepióra

    2013-12-01

    Full Text Available This study presents root colonization of Deschampsia cespitosa growing in the immediate vicinity of a former Pb/Zn smelter by arbuscular mycorhizal fungi (AMF and dark septated endophytes (DSE at different soil depths. AMF spores and species distribution in soil profile were also assessed. Arbuscular mycorrhiza (AM and DSE were found in D. cespitosa roots at all investigated soil levels. However, mycorrhizal colonization in topsoil was extremely low with sporadically occurring arbuscules. AM parameters: frequency of mycorrhization of root fragments (F%, intensity of root cortex colonization (M%, intensity of colonization within individual mycorrhizal roots (m%, and arbuscule abundance in the root system (A% were markedly higher at 20–40, 40–60 cm soil levels and differed in a statistically significant manner from AM parameters from 0–10 and 10–20 cm layers. Mycorrhizal colonization was negatively correlated with bioavailable Cd, Pb and Zn concentrations. The number of AMF spores in topsoil was very low and increased with soil depth (20–40 and 40–60 cm. At the study area spores of three morphologically distinctive AMF species were found: Archaeospora trappei, Funneliformis mosseae and Scutellospora dipurpurescens. The fourth species Glomus tenue colonized roots of D. cespitosa and was observed in the root cortex at 20–40 and 40–60 soil depth, however, its spores were not found at the site.

  7. [Effects of ryegrass and arbuscular mycorrhiza on activities of antioxidant enzymes, accumulation and chemical forms of cadmium in different varieties of tomato].

    Science.gov (United States)

    Jiang, Ling; Yang, Yun; Xu, Wei-Hong; Wang, Chong-Li; Chen, Rong; Xiong, Shi-Juan; Xie, Wen-Wen; Zhang, Jin-Zhong; Xiong, Zhi-Ting; Wang, Zheng-Yin; Xie, De-Ti

    2014-06-01

    Pot experiments were carried out to investigate the effects of ryegrass and arbuscular mycorrhiza on the plant growth, malondialdehyde (MDA), antioxidant enzyme activities of leaf and root, accumulation and chemical forms of cadmium (Cd) in tow varieties of tomato when exposed to Cd (20 mg x kg(-1)). The results showed that dry weights of fruit and plant, and contents of malondialdehyde (MDA) and antioxidant enzyme activities of leaf and root, and concentrations and accumulations of Cd significantly differed between two varieties of tomato. Dry weights of fruit, roots, stem, leaf and plant were increased by single or combined remediation of ryegrass and arbuscular mycorrhiza, while MDA contents and antioxidant enzyme activities of leaf and root reduced. The total extractable Cd, F(E), F(W), F(NaCl), F(HAc), F(HCl), and F(R) in fruit of two varieties of tomato reduced by 19.4% - 52.4%, 31.0% - 75.2%, 19.7% - 59.1%, 3.1% - 48.2%, 20.0% - 65.0%, 40.7% - 100.0% and 15.2% - 50.0%, respectively. Cadmium accumulations in tomato were in the order of leaf > stem > fruit > root. Cadmium concentrations in leaf, stem, root and fruit of both varieties decreased by single or combined remediation of ryegrass and arbuscular mycorrhiza, and Cd accumulations of stem and plant of two varieties also reduced. Cd accumulations in fruit of two varieties decreased by 42.9% and 43.7% in the combined remediation treatments, respectively. Tolerance and resistance of 'LUO BEI QI' on Cd was more than 'De Fu mm-8', and Cd concentrations and Cd accumulations in fruit and plant were in the order of 'LUO BEI QI' arbuscular mycorrhiza.

  8. Fall cover cropping can increase arbuscular mycorrhizae in soils supporting intensive agricultural production

    Science.gov (United States)

    Intensive agricultural practices, such as tillage, monocropping, seasonal fallow periods, and inorganic nutrient application have been shown to reduce arbuscular mycorrrhizal fungi (AMF) populations and thus may reduce benefits frequently provided to crops by AMF, such as nutrient acquisition, disea...

  9. The role of the arbuscular mycorrhiza-associated rhizobacteria in the biocontrol of soilborne phyto pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Lioussanne, L.

    2010-07-01

    The mutualistic symbiosis of most land plants with arbuscular mycorrhizal (AM) fungi has been shown to favor mineral and water nutrition and to increase resistance to abiotic and biotic stresses. This review reports the main mechanisms involved in the control of the disease symptoms and of the intraradical proliferation of soilborne phytopathogens by root colonization with AM fungi, with a special emphasis on the role of the rhizobacteria shown to be specifically associated with the AM extraradical network and the mycorrhizosphere (the soil zone with particular characteristics under the influence of the root/AM association). The mycorrhizosphere would constitute an environment conducive to microorganisms antagonistic to pathogen proliferation. Moreover, attempts to identify rhizobacteria from AM structures and/or the mycorrhizosphere often lead to the isolation of organisms showing strong properties of antagonism on various soilborne pathogens. The ability of AM fungi to control soilborne diseases would be strongly related to their capacity to specifically stimulate the establishment of rhizobacteria unfavorable to pathogen development within the mycorrhizosphere before root infection. Current knowledge concerning the mechanisms involved in AM/rhizobacteria interactions are also described in this review. (Author) 101 refs.

  10. Arbuscular Mycorrhiza Prevents Suppression of Actual Nitrification Rates in the (Myco-)Rhizosphere of Plantago lanceolata

    Institute of Scientific and Technical Information of China (English)

    S.D.VERESOGLOU

    2012-01-01

    The vast majority of herbaceous plants engage into arbuscular mycorrhizal (AM) symbioses and consideration of their mycorrhizal status should be embodied in studies of plant-microbe interactions.To establish reliable AM contrasts,however,a sterilized re-inoculation procedure is commonly adopted.It was questioned whether the specific approach is sufficient for the studies targeting the bacterial domain,specifically nitrifiers,a group of autotrophic,slow growing microbes.In a controlled experiment mycorrhizal and non-mycorrhizal Plantago lanceolata were grown up in compartmentalized pots to study the AM effect on nitrification rates in the plant rhizosphere.Nitrification rates were assayed following an extensive 3-week bacterial equilibration step of the re-inoculated soil and a 13-week plant growth period in a controlled environment.Under these specific conditions,the nitrification potential levels at harvest were exceptionally low,and actual nitrification rates of the root compartment of non-mycorrhizal P.lanceolata were significantly lower than those of any other compartment.It is then argued that the specific effects should be attributed to the alleged higher growth rates of non-mycorrhizal plants that are known to occur early in the AM experiment.It is concluded that the specific experimental approach is not suitable for the study of microbes with slow growth rates.

  11. 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...

  12. Resource stoichiometry elucidates the structure and function of arbuscular mycorrhizas across scales.

    Science.gov (United States)

    Johnson, Nancy Collins

    2010-02-01

    Despite the fact that arbuscular mycorrhizal (AM) associations are among the most ancient, abundant and important symbioses in terrestrial ecosystems, there are currently few unifying theories that can be used to help understand the factors that control their structure and function. This review explores how a stoichiometric perspective facilitates integration of three complementary ecological and evolutionary models of mycorrhizal structure and function. AM symbiotic function should be governed by the relative availability of carbon, nitrogen and phosphorus (trade balance model) and allocation to plant and fungal structures should depend on the availabilities of these resources (functional equilibrium model). Moreover, in an evolutionary framework, communities of plants and AM fungi are predicted to adapt to each other and their local soil environment (co-adaptation model). Anthropogenic enrichment of essential resources in the environment is known to impact AM symbioses. A more predictive theory of AM structure and function will help us to better understand how these impacts may influence plant communities and ecosystem properties.

  13. Gibberellin–Abscisic Acid Balances during Arbuscular Mycorrhiza Formation in Tomato

    Science.gov (United States)

    Martín-Rodríguez, José A.; Huertas, Raúl; Ho-Plágaro, Tania; Ocampo, Juan A.; Turečková, Veronika; Tarkowská, Danuše; Ludwig-Müller, Jutta; García-Garrido, José M.

    2016-01-01

    Plant hormones have become appropriate candidates for driving functional plant mycorrhization programs, including the processes that regulate the formation of arbuscules in arbuscular mycorrhizal (AM) symbiosis. Here, we examine the role played by ABA/GA interactions regulating the formation of AM in tomato. We report differences in ABA and GA metabolism between control and mycorrhizal roots. Active synthesis and catabolism of ABA occur in AM roots. GAs level increases as a consequence of a symbiosis-induced mechanism that requires functional arbuscules which in turn is dependent on a functional ABA pathway. A negative interaction in their metabolism has been demonstrated. ABA attenuates GA-biosynthetic and increases GA-catabolic gene expression leading to a reduction in bioactive GAs. Vice versa, GA activated ABA catabolism mainly in mycorrhizal roots. The negative impact of GA3 on arbuscule abundance in wild-type plants is partially offset by treatment with ABA and the application of a GA biosynthesis inhibitor rescued the arbuscule abundance in the ABA-deficient sitiens mutant. These findings, coupled with the evidence that ABA application leads to reduce bioactive GA1, support the hypothesis that ABA could act modifying bioactive GA level to regulate AM. Taken together, our results suggest that these hormones perform essential functions and antagonize each other by oppositely regulating AM formation in tomato roots. PMID:27602046

  14. Gibberellin-Abscisic Acid Balances during Arbuscular Mycorrhiza Formation in Tomato.

    Science.gov (United States)

    Martín-Rodríguez, José A; Huertas, Raúl; Ho-Plágaro, Tania; Ocampo, Juan A; Turečková, Veronika; Tarkowská, Danuše; Ludwig-Müller, Jutta; García-Garrido, José M

    2016-01-01

    Plant hormones have become appropriate candidates for driving functional plant mycorrhization programs, including the processes that regulate the formation of arbuscules in arbuscular mycorrhizal (AM) symbiosis. Here, we examine the role played by ABA/GA interactions regulating the formation of AM in tomato. We report differences in ABA and GA metabolism between control and mycorrhizal roots. Active synthesis and catabolism of ABA occur in AM roots. GAs level increases as a consequence of a symbiosis-induced mechanism that requires functional arbuscules which in turn is dependent on a functional ABA pathway. A negative interaction in their metabolism has been demonstrated. ABA attenuates GA-biosynthetic and increases GA-catabolic gene expression leading to a reduction in bioactive GAs. Vice versa, GA activated ABA catabolism mainly in mycorrhizal roots. The negative impact of GA3 on arbuscule abundance in wild-type plants is partially offset by treatment with ABA and the application of a GA biosynthesis inhibitor rescued the arbuscule abundance in the ABA-deficient sitiens mutant. These findings, coupled with the evidence that ABA application leads to reduce bioactive GA1, support the hypothesis that ABA could act modifying bioactive GA level to regulate AM. Taken together, our results suggest that these hormones perform essential functions and antagonize each other by oppositely regulating AM formation in tomato roots.

  15. Effects of arbuscular mycorrhiza and phosphorus application on artemisinin concentration in Artemisia annua L.

    Science.gov (United States)

    Kapoor, Rupam; Chaudhary, Vidhi; Bhatnagar, A K

    2007-10-01

    Annual wormwood (Artemisia annua L.) produces an array of complex terpenoids including artemisinin, a compound of current interest in the treatment of drug-resistant malaria. However, this promising antimalarial compound remains expensive and is hardly available on the global scale. Synthesis of artemisinin has not been proved to be feasible commercially. Therefore, increase in yield of naturally occurring artemisinin is an important area of investigation. The effects of inoculation by two arbuscular mycorrhizal (AM) fungi, Glomus macrocarpum and Glomus fasciculatum, either alone or supplemented with P-fertilizer, on artemisinin concentration in A. annua were studied. The concentration of artemisinin was determined by reverse-phase high-performance liquid chromatography with UV detection. The two fungi significantly increased concentration of artemisinin in the herb. Although there was significant increase in concentration of artemisinin in nonmycorrhizal P-fertilized plants as compared to control, the extent of the increase was less compared to mycorrhizal plants grown with or without P-fertilization. This suggests that the increase in artemisinin concentration may not be entirely attributed to enhanced P-nutrition and improved growth. A strong positive linear correlation was observed between glandular trichome density on leaves and artemisinin concentration. Mycorrhizal plants possessed higher foliar glandular trichome (site for artemisinin biosynthesis and sequestration) density compared to nonmycorrhizal plants. Glandular trichome density was not influenced by P-fertilizer application. The study suggests a potential role of AM fungi in improving the concentration of artemisinin in A. annua.

  16. Gibberellin-abscisic acid balances during arbuscular mycorrhiza formation in tomato

    Directory of Open Access Journals (Sweden)

    José Angel Martín-Rodríguez

    2016-08-01

    Full Text Available Plant hormones become appropriate candidates for driving functional plant mycorrhization programs, including the processes that regulate the formation of arbuscules in Arbuscular Mycorrhizal (AM symbiosis. Here, we examine the role played by ABA/GA interactions regulating the formation of AM in tomato. We report differences in ABA and GA metabolism between control and mycorrhizal roots. Active synthesis and catabolism of ABA occur in AM roots. GAs level increases as a consequence of a symbiosis-induced mechanism that requires functional arbuscules which in turn is dependent on a functional ABA pathway. A negative interaction in their metabolism has been demonstrated. ABA attenuates GA-biosynthetic and increases GA-catabolic gene expression leading to a reduction in bioactive GAs. Vice versa, GA activated ABA catabolism mainly in mycorrhizal roots. The negative impact of GA3 on arbuscule abundance in wild-type plants is partially offset by treatment with ABA and the application of a GA biosynthesis inhibitor rescued the arbuscule abundance in the ABA-deficient sitiens mutant. These findings, coupled with the evidence that ABA application leads to reduce bioactive GA1, support the hypothesis that ABA could act modifying bioactive GA level to regulate AM. Taken together, our results suggest that these hormones perform essential functions and antagonize each other by oppositely regulating AM formation in tomato roots.

  17. Trypan blue as a fluorochrome for confocal laser scanning microscopy of arbuscular mycorrhizae in three mangroves.

    Science.gov (United States)

    Kumar, T; Majumdar, A; Das, P; Sarafis, V; Ghose, M

    2008-06-01

    Roots of three mangroves, Acanthus ilicifolius, Ceriops tagal and Excoecaria agallocha, collected from forests of the Sundarbans of India were stained with trypan blue to observe arbuscular mycorrhizal colonization. Spores of arbuscular mycorrhizal fungi isolated from rhizospheric soil, collected together with the root samples, also were stained for testing the suitability of the dye as a fluorochrome. Confocal laser scanning microscopy images were constructed. A. ilicifolius and E. agallocha exhibited "Arum" type colonization with highly branched arbuscules, whereas C. tagal showed "Paris" type association with clumped and collapsed arbuscules. We demonstrated that trypan blue is a suitable fluorochrome for staining arbuscular mycorrhizal fungal spores, fungal hyphae, arbuscules and vesicles, which presumably have a considerable amount of surface chitin. It appears that as the integration of chitin into the fungal cell wall changes, its accessibility to trypan blue dye also changes.

  18. Influence of Arbuscular Mycorrhiza on Membrane Lipid Peroxidation and Soluble Sugar Content of Soybean under Salt Stress

    Directory of Open Access Journals (Sweden)

    Ali Moradi

    2015-03-01

    Full Text Available The influence of the arbuscular mycorrhizal (AM fungus, Glomus mosseae, on characteristics of growth, membrane lipid peroxidation and soluble sugar content in the shoots and roots of soybean (Glycine max plants was studied in pot culture under salt stress. The experiment was arranged as a factorial in Randomized Complete Block Design (RCBD with four replications in greenhouse of College of Agriculture, Tehran University, Iran. The plants inoculated with mycorrhiza had significantly greater shoot and root biomass than the nonmycorrhizal plants at all salinity levels. AM symbiosis decreased membrane relative permeability and malondialdehyde content in shoots and roots. The soluble sugar content in roots was higher in mycorrhizal than nonmycorrhizal plants, but there was no significant difference in soluble sugar content in shoots between mycorrhizal and nonmycorrhizal plants. The results indicate that the AM fungus is capable of alleviating the damage caused by salt stress on soybean plants by reducing membrane lipid peroxidation and increasing the accumulation of soluble sugar content. Consequently, arbuscular mycorrhiza formation highly enhanced the salinity tolerance of soybean plant, which increased host biomass and promoted plant growth. Normal 0 21 false false false HR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;}

  19. 13C Incorporation into Signature Fatty Acids as an Assay for Carbon Allocation in Arbuscular Mycorrhiza

    Science.gov (United States)

    Olsson, Pål Axel; van Aarle, Ingrid M.; Gavito, Mayra E.; Bengtson, Per; Bengtsson, Göran

    2005-01-01

    The ubiquitous arbuscular mycorrhizal fungi consume significant amounts of plant assimilated C, but this C flow has been difficult to quantify. The neutral lipid fatty acid 16:1ω5 is a quantitative signature for most arbuscular mycorrhizal fungi in roots and soil. We measured carbon transfer from four plant species to the arbuscular mycorrhizal fungus Glomus intraradices by estimating 13C enrichment of 16:1ω5 and compared it with 13C enrichment of total root and mycelial C. Carbon allocation to mycelia was detected within 1 day in monoxenic arbuscular mycorrhizal root cultures labeled with [13C]glucose. The 13C enrichment of neutral lipid fatty acid 16:1ω5 extracted from roots increased from 0.14% 1 day after labeling to 2.2% 7 days after labeling. The colonized roots usually were more enriched for 13C in the arbuscular mycorrhizal fungal neutral lipid fatty acid 16:1ω5 than for the root specific neutral lipid fatty acid 18:2ω6,9. We labeled plant assimilates by using 13CO2 in whole-plant experiments. The extraradical mycelium often was more enriched for 13C than was the intraradical mycelium, suggesting rapid translocation of carbon to and more active growth by the extraradical mycelium. Since there was a good correlation between 13C enrichment in neutral lipid fatty acid 16:1ω5 and total 13C in extraradical mycelia in different systems (r2 = 0.94), we propose that the total amount of labeled C in intraradical and extraradical mycelium can be calculated from the 13C enrichment of 16:1ω5. The method described enables evaluation of C flow from plants to arbuscular mycorrhizal fungi to be made without extraction, purification and identification of fungal mycelia. PMID:15870350

  20. Age versus stage: does ontogeny modify the effect of phosphorus and arbuscular mycorrhizas on above- and below-ground defence in forage sorghum?

    Science.gov (United States)

    Miller, Rebecca E; Gleadow, Roslyn M; Cavagnaro, Timothy R

    2014-04-01

    Arbuscular mycorrhizas (AM) can increase plant acquisition of P and N. No published studies have investigated the impact of P and AM on the allocation of N to the plant defence, cyanogenic glucosides. We investigated the effects of soil P and AM on cyanogenic glucoside (dhurrin) concentration in roots and shoots of two forage sorghum lines differing in cyanogenic potential (HCNp). Two harvest times allowed plants grown at high and low P to be compared at the same age and the same size, to take account of known ontogenetic changes in shoot HCNp. P responses were dependent on ontogeny and tissue type. At the same age, P-limited plants were smaller and had higher shoot HCNp but lower root HCNp. Ontogenetically controlled comparisons showed a P effect of lesser magnitude, and that there was also an increase in the allocation of N to dhurrin in shoots of P-limited plants. Colonization by AM had little effect on shoot HCNp, but increased root HCNp and the allocation of N to dhurrin in roots. Divergent responses of roots and shoots to P, AM and with ontogeny demonstrate the importance of broadening the predominantly foliar focus of plant defence studies/theory, and of ontogenetically controlled comparisons. © 2013 John Wiley & Sons Ltd.

  1. Influence of arbuscular mycorrhiza on the growth and antioxidative activity in cyclamen under heat stress.

    Science.gov (United States)

    Maya, Moslama Aktar; Matsubara, Yoh-ichi

    2013-07-01

    The influence of the arbuscular mycorrhizal (AM) fungus, Glomus fasciculatum, on the growth, heat stress responses and the antioxidative activity in cyclamen (Cyclamen persicum Mill.) plants was studied. Cyclamen plants (inoculated or not with the AM fungus) were placed in a commercial potting media at 17-20 °C for 12 weeks in a greenhouse and subsequently subjected to two temperature conditions in a growth chamber. Initially, plants were grown at 20 °C for 4 weeks as a no heat stress (HS-) condition, followed by 30 °C for another 4 weeks as a heat stress (HS+) condition. Different morphological and physiological growth parameters were compared between G. fasciculatum-inoculated and noninoculated plants. The mycorrhizal symbiosis markedly enhanced biomass production and HS + responses in plants compared to that in the controls. A severe rate of leaf browning (80-100%) was observed in control plants, whereas the mycorrhizal plants showed a minimum rate of leaf browning under HS + conditions. The mycorrhizal plants showed an increase activity of antioxidative enzymes such as superoxide dismutase and ascorbate peroxidase, as well as an increase in ascorbic acid and polyphenol contents. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity also showed a greater response in mycorrhizal plants than in the control plants under each temperature condition. The results indicate that in cyclamen plants, AM fungal colonisation alleviated heat stress damage through an increased antioxidative activity and that the mycorrhizal symbiosis strongly enhanced temperature stress tolerance which promoted plant growth and increased the host biomass under heat stress.

  2. 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.

  3. Arbuscular fungi and mycorrhizae in agricultural soils of the Western Pomerania.II. Distribution of arbuscular fungi

    Directory of Open Access Journals (Sweden)

    Anna Iwaniuk

    2014-08-01

    Full Text Available This part of the two-part paper of arbuscular mycorrhizal fungi (AMF of the phylum Glomeromycota of agricultural soils of the Western Pomerania, north-western Poland, presents the distribution of 26 species of these fungi in both the sites considered in this study and cultivated soils of other regions of Poland and the world investigated previously. The fungi were isolated from both field-collected rhizosphere soil and root mixtures and trap cultures established from each field sample and seeded with three species of plant hosts. Among the fungal species characterized, 18 are of the genus Glomus, one each of the genera Archaeospora, Entrophospora and Paraglomus and three and two of the genera Acaulospora and Scutellospora, respectively.

  4. Relative quantitative RT-PCR to study the expression of plant nutrient transporters in arbuscular mycorrhizas

    DEFF Research Database (Denmark)

    Burleigh, S.H.

    2001-01-01

    The influence of arbuscular mycorrhizal fungi (AMF) on the expression of plant nutrient transporters was studied using a relative. quantitative reverse-transcription polymerase chain-reaction (RQRT-PCR) technique. Reverse-transcribed 18S rRNA was used to standardize the treatments. The technique...

  5. Occurence of arbuscular mycorrhiza and extomycorrhiza on Leptospermum scoparium from the Rakaia catchment, Canterbury.

    NARCIS (Netherlands)

    Weijtmans, K.; Davis, M.; Clinton, P.; Kuyper, T.W.; Greenfield, L.

    2007-01-01

    Leptospermum is one of only three New Zealand genera that are colonised by ectomycorrhizal (EM) fungi, and L. scoparium is one of the very few New Zealand species that can be colonised by both arbuscular mycorrhizal (AM) and EM fungi. This study examined AM and EM colonisation on L. scoparium

  6. Dose-response relationships between four pesticides and phosphorus uptake by hyphae of arbuscular mycorrhizas

    DEFF Research Database (Denmark)

    Schweiger, P.F.; Jakobsen, I.

    1998-01-01

    The effect of the fungicides carbendazim, fenpropimorph and propiconazole and of the insecticide dimethoate on plant P uptake via external hyphae of arbuscular mycorrhizal (AM) fungi was examined. Mycorrhizal plants were grown in a two-compartment system where a root-free hyphal compartment...

  7. Global environmental change and the biology of arbuscular mycorrhizas: gaps and challenges

    DEFF Research Database (Denmark)

    Fitter, A.H.; Heinemeyer, A.; Husband, R.

    2004-01-01

    Our ability to make predictions about the impact of global environmental change on arbuscular mycorrhizal (AM) fungi and on their role in regulating biotic response to such change is seriously hampered by our lack of knowledge of the basic biology of these ubiquitous organisms. Current information...

  8. Effect of arbuscular mycorrhiza fungi on growth and development of onion and wild relatives

    NARCIS (Netherlands)

    Scholten, O.M.; Galvan-Vivero, G.; Burger-Meijer, K.; Baar, J.; Kik, C.

    2006-01-01

    Arbuscular mycorrhizal fungi play an important role in the uptake of nutrients and water from soil. Onions, Allium cepa L., are plants with a shallow root system. As a result, onion plants need a lot of fertiziler for their growth. Furthermore, onion plants are sensitive to drought. The aim of the

  9. Influences of agricultural management practices on Arbuscular Mycorrhiza Fungal symbioses in Kenyan agro-ecosystems

    NARCIS (Netherlands)

    Muriithi-Muchane, M.N.

    2013-01-01

    Conservation agriculture (CA) and integrated soil fertility management (ISFM) practices are receiving increased attention as pathways to sustainable high-production agriculture in sub-Saharan Africa. However, little is known about the effects of these practices on arbuscular mycorrhizal fungi (AMF).

  10. Weed Flora and Dormant-season cover crops have no effects on arbuscular mycorrhizae of grapevine

    Science.gov (United States)

    We tested the hypotheses that mycorrhizal colonization of a perennial crop increases with a high frequency of mycorrhizal hosts within the plant community, and that a high diversity of mycorrhizal hosts is associated with a high diversity of arbuscular mycorrhizal fungi (AMF) on the perennial crop. ...

  11. Effect of zinc rates, arbuscular mycorrhiza and two types of organic matter on corn growth and micronutrients-uptake in a calcareous soil

    Directory of Open Access Journals (Sweden)

    L. Gholami

    2016-09-01

    Full Text Available A greenhouse experiment was conducted to study the effect of zinc rates, arbuscular mycorrhiza and organic matter, on corn growth and micronutrients-uptake in a calcareous soil. Experimental design was factorial based on complete randomized design with 3 replications. Treatments consisted of 3 levels of Zn (0, 5 and 10 mg Zn/kg, 2 types of organic manure (sheep manure and municipal waste compost, each at 0 or 1% w/w and 2 levels of mycorrhiza (no inoculation and inoculation with Glomus intraradices. Plants were harvested 8 weeks after emergence and used for chemical analysis. Roots were used to determine the degree of colonization. Results showed that application of Zn increased plant dry matter weight, total Zn and Cu uptake, root mycorrhizal colonization and decreased total Fe and Mn uptake. Arbuscular mycorrhiza increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake. Application of both organic manures increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake. 

  12. NENA, a Lotus japonicus Homolog of Sec13, Is Required for Rhizodermal Infection by Arbuscular Mycorrhiza Fungi and Rhizobia but Dispensable for Cortical Endosymbiotic Development[C][W

    Science.gov (United States)

    Groth, Martin; Takeda, Naoya; Perry, Jillian; Uchida, Hisaki; Dräxl, Stephan; Brachmann, Andreas; Sato, Shusei; Tabata, Satoshi; Kawaguchi, Masayoshi; Wang, Trevor L.; Parniske, Martin

    2010-01-01

    Legumes form symbioses with arbuscular mycorrhiza (AM) fungi and nitrogen fixing root nodule bacteria. Intracellular root infection by either endosymbiont is controlled by the activation of the calcium and calmodulin-dependent kinase (CCaMK), a central regulatory component of the plant’s common symbiosis signaling network. We performed a microscopy screen for Lotus japonicus mutants defective in AM development and isolated a mutant, nena, that aborted fungal infection in the rhizodermis. NENA encodes a WD40 repeat protein related to the nucleoporins Sec13 and Seh1. Localization of NENA to the nuclear rim and yeast two-hybrid experiments indicated a role for NENA in a conserved subcomplex of the nuclear pore scaffold. Although nena mutants were able to form pink nodules in symbiosis with Mesorhizobium loti, root hair infection was not observed. Moreover, Nod factor induction of the symbiotic genes NIN, SbtM4, and SbtS, as well as perinuclear calcium spiking, were impaired. Detailed phenotypic analyses of nena mutants revealed a rhizobial infection mode that overcame the lack of rhizodermal responsiveness and carried the hallmarks of crack entry, including a requirement for ethylene. CCaMK-dependent processes were only abolished in the rhizodermis but not in the cortex of nena mutants. These data support the concept of tissue-specific components for the activation of CCaMK. PMID:20675572

  13. Arbuscular mycorrhizas and ectomycorrhizas of Uapaca bojeri L. (Euphorbiaceae): sporophore diversity, patterns of root colonization, and effects on seedling growth and soil microbial catabolic diversity.

    Science.gov (United States)

    Ramanankierana, Naina; Ducousso, Marc; Rakotoarimanga, Nirina; Prin, Yves; Thioulouse, Jean; Randrianjohany, Emile; Ramaroson, Luciano; Kisa, Marija; Galiana, Antoine; Duponnois, Robin

    2007-05-01

    The main objectives of this study were (1) to describe the diversity of mycorrhizal fungal communities associated with Uapaca bojeri, an endemic Euphorbiaceae of Madagascar, and (2) to determine the potential benefits of inoculation with mycorrhizal fungi [ectomycorrhizal and/or arbuscular mycorrhizal (AM) fungi] on the growth of this tree species and on the functional diversity of soil microflora. Ninety-four sporophores were collected from three survey sites. They were identified as belonging to the ectomycorrhizal genera Afroboletus, Amanita, Boletus, Cantharellus, Lactarius, Leccinum, Rubinoboletus, Scleroderma, Tricholoma, and Xerocomus. Russula was the most frequent ectomycorrhizal genus recorded under U. bojeri. AM structures (vesicles and hyphae) were detected from the roots in all surveyed sites. In addition, this study showed that this tree species is highly dependent on both types of mycorrhiza, and controlled ectomycorrhization of this Uapaca species strongly influences soil microbial catabolic diversity. These results showed that the complex symbiotic status of U. bojeri could be managed to optimize its development in degraded areas. The use of selected mycorrhizal fungi such the Scleroderma Sc1 isolate in nursery conditions could be of great interest as (1) this fungal strain is very competitive against native symbiotic microflora, and (2) the fungal inoculation improves the catabolic potentialities of the soil microflora.

  14. [Disease resistance signal transfer between roots of different tomato plants through common arbuscular mycorrhiza networks].

    Science.gov (United States)

    Xie, Li-Jun; Song, Yuan-Yuan; Zeng, Ren-Sen; Wang, Rui-Long; Wei, Xiao-Chen; Ye, Mao; Hu, Lin; Zhang, Hui

    2012-05-01

    Common mycorrhizal networks (CMNs) are the underground conduits of nutrient exchange between plants. However, whether the CMNs can serve as the underground conduits of chemical communication to transfer the disease resistance signals between plants are unknown. By inoculating arbuscular mycorrhizal fungus (AMF) Glomus mosseae to establish CMNs between 'donor' and 'receiver' tomato plants, and by inoculating Alternaria solani, the causal agent of tomato early blight disease, to the 'donor' plants, this paper studied whether the potential disease resistance signals can be transferred between the 'donor' and 'receiver' plants roots. The real time RT-PCR analysis showed that after inoculation with A. solani, the AMF-inoculated 'donor' plants had strong expression of three test defense-related genes in roots, with the transcript levels of the phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX) and chitinase (PR3) being significantly higher than those in the roots of the 'donor' plants only inoculated with A. solani, not inoculated with both A. solani and AMF, and only inoculated with AMF. More importantly, in the presence of CMNs, the expression levels of the three genes in the roots of the 'receiver' plants were significantly higher than those of the 'receiver' plants without CMNs connection, with the connection blocking, and with the connection but the 'donor' plants not A. solani-inoculated. Compared with the control (without CMNs connection), the transcript level of the PAL, LOX and PR3 in the roots of the 'receiver' plants having CMNs connection with the 'donor' plants was 4.2-, 4.5- and 3.5-fold higher, respectively. In addition, the 'donor' plants activated their defensive responses more quickly than the 'receiver' plants (18 and 65 h vs. 100 and 140 h). These findings suggested that the disease resistance signals produced by the pathogen-induced 'donor' tomato plant roots could be transferred to the 'receiver' plant roots through CMNs.

  15. Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels.

    Science.gov (United States)

    Mandal, Shantanu; Upadhyay, Shivangi; Wajid, Saima; Ram, Mauji; Jain, Dharam Chand; Singh, Ved Pal; Abdin, Malik Zainul; Kapoor, Rupam

    2015-07-01

    It is becoming increasingly evident that the formation of arbuscular mycorrhiza (AM) enhances secondary metabolite production in shoots. Despite mounting evidence, relatively little is known about the underlying mechanisms. This study suggests that increase in artemisinin concentration in Artemisia annua colonized by Rhizophagus intraradices is due to altered trichome density as well as transcriptional patterns that are mediated via enhanced jasmonic acid (JA) levels. Mycorrhizal (M) plants had higher JA levels in leaf tissue that may be due to induction of an allene oxidase synthase gene (AOS), encoding one of the key enzymes for JA production. Non-mycorrhizal (NM) plants were exogenously supplied with a range of methyl jasmonic acid concentrations. When leaves of NM and M plants with similar levels of endogenous JA were compared, these matched closely in terms of shoot trichome density, artemisinin concentration, and transcript profile of artemisinin biosynthesis genes. Mycorrhization increased artemisinin levels by increasing glandular trichome density and transcriptional activation of artemisinin biosynthesis genes. Transcriptional analysis of some rate-limiting enzymes of mevalonate and methyl erythritol phosphate (MEP) pathways revealed that AM increases isoprenoids by induction of the MEP pathway. A decline in artemisinin concentration in shoots of NM and M plants treated with ibuprofen (an inhibitor of JA biosynthesis) further confirmed the implication of JA in the mechanism of artemisinin production.

  16. Colonization of Greek olive cultivars' root system by arbuscular mycorrhiza fungus: root morphology, growth, and mineral nutrition of olive plants

    Directory of Open Access Journals (Sweden)

    Theocharis Chatzistathis

    2013-06-01

    Full Text Available Rooted leafy cuttings of three Greek olive (Olea europaea L. cultivars (Koroneiki, Kothreiki and Chondrolia Chalkidikis were grown for six months in three soil types, in an experimental greenhouse, in order to investigate: i if their root system was colonized by arbuscular mycorrhiza fungus (AMF genus and, ii if genotypic differences concerning growth and mineral nutrition of olive plants existed. Gigaspora sp. colonized the root system of the three cultivars studied, while Glomus sp. colonized only the root system of 'Koroneiki'. Furthermore, in most cases root colonization by AMF differed among cultivars and soil types. The maximum root colonization, in all soils, was found in 'Chondrolia Chalkidikis'. In the three soils studied, the ratio shoot dry weight (SDW/ root dry weight (RDW was higher in 'Chondrolia Chalkidikis' than in the other two cultivars. Furthermore, root system morphology of the three olive cultivars was completely different, irrespectively of soil type. Leaf Mn, Fe, Zn, Ca, Mg, K and P concentrations, as well as total per plant nutrient content and nutrient use efficiency, differed among cultivars under the same soil conditions. These differences concerning root morphology, SDW/RDW, as well as nutrient uptake and use efficiency, could be possibly ascribed to the differential AMF colonization by Glomus sp. and Gigaspora sp.

  17. Interaction of brassinosteroid functions and sucrose transporter SlSUT2 regulate the formation of arbuscular mycorrhiza.

    Science.gov (United States)

    Bitterlich, Michael; Krügel, Undine; Boldt-Burisch, Katja; Franken, Philipp; Kühn, Christina

    2014-01-01

    Transgenic tomato plants with reduced expression of the sucrose transporter SlSUT2 showed higher efficiency of mycorrhization suggesting a sucrose retrieval function of SlSUT2 from the peri-arbuscular space back into the cell cytoplasm plant cytoplasm thereby limiting mycorrhiza fungal development. Sucrose uptake in colonized root cells requires efficient plasma membrane-targeting of SlSUT2 which is often retained intracellularly in vacuolar vesicles. Protein-protein interaction studies suggested a link between SISUT2 function and components of brassinosteroid biosynthesis and signaling. Indeed, the tomato DWARF mutant d(x) defective in BR synthesis (1) showed significantly reduced mycorrhization parameters. (2) The question has been raised whether the impact of brassinosteroids on mycorrhization is a general phenomenon. Here, we include a rice mutant defective in DIM1/DWARF1 involved in BR biosynthesis to investigate the effects on mycorrhization. A model is presented where brassinolides are able to impact mycorrhization by activating SUT2 internalization and inhibiting its role in sucrose retrieval.

  18. Cellular imaging of cadmium in resin sections of arbuscular mycorrhizas using synchrotron micro X-ray fluorescence.

    Science.gov (United States)

    Nayuki, Keiichiro; Chen, Baodong; Ohtomo, Ryo; Kuga, Yukari

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi function as extended roots and take an active part in plant acquisition of nutrients and also soil pollutants, such as heavy metals. The objective of this study was to establish a method to observe the localization of cadmium (Cd) Kα at subcellular levels using X-ray fluorescence (XRF) imaging with a synchrotron irradiation microbeam in resin-embedded sections of mycorrhizas. To evaluate the methodology, distributions of Cd in high-pressure-frozen Lotus japonicus-Rhizophagus irregularis mycorrhizal roots were compared between two treatments; Cd was exposed either to the roots or to the extraradical hyphae. Results showed that, in the latter treatment, Cd was restricted to fungal structures, whereas in the former, Cd was detected in cell walls of the two organisms. Plunge-frozen extraradical mycelium of Gigaspora margarita exposed to Cd showed high signals of Cd in the cell walls and vacuoles, and low in the cytoplasm. With selective staining and elemental mapping by electron-dispersive X-ray spectrometry (EDS), a positive correlation between distributions of Cd and P was revealed in the vacuole, which suggested polyP as a counter ion of Cd. These results indicated that there was no Cd relocation in rapidly frozen resin-embedded materials, therefore supporting the usefulness of this methodology.

  19. SymRK defines a common genetic basis for plant root endosymbioses with arbuscular mycorrhiza fungi, rhizobia, and Frankiabacteria

    Science.gov (United States)

    Gherbi, Hassen; Markmann, Katharina; Svistoonoff, Sergio; Estevan, Joan; Autran, Daphné; Giczey, Gabor; Auguy, Florence; Péret, Benjamin; Laplaze, Laurent; Franche, Claudine; Parniske, Martin; Bogusz, Didier

    2008-01-01

    Root endosymbioses vitally contribute to plant nutrition and fitness worldwide. Nitrogen-fixing root nodulation, confined to four plant orders, encompasses two distinct types of associations, the interaction of legumes (Fabales) with rhizobia bacteria and actinorhizal symbioses, where the bacterial symbionts are actinomycetes of the genus Frankia. Although several genetic components of the host–symbiont interaction have been identified in legumes, the genetic basis of actinorhiza formation is unknown. Here, we show that the receptor-like kinase gene SymRK, which is required for nodulation in legumes, is also necessary for actinorhiza formation in the tree Casuarina glauca. This indicates that both types of nodulation symbiosis share genetic components. Like several other legume genes involved in the interaction with rhizobia, SymRK is also required for the interaction with arbuscular mycorrhiza (AM) fungi. We show that SymRK is involved in AM formation in C. glauca as well and can restore both nodulation and AM symbioses in a Lotus japonicus symrk mutant. Taken together, our results demonstrate that SymRK functions as a vital component of the genetic basis for both plant–fungal and plant–bacterial endosymbioses and is conserved between legumes and actinorhiza-forming Fagales. PMID:18316735

  20. Interaction of brassinosteroid functions and sucrose transporter SlSUT2 regulate the formation of arbuscular mycorrhiza

    Science.gov (United States)

    Bitterlich, Michael; Krügel, Undine; Boldt-Burisch, Katja; Franken, Philipp; Kühn, Christina

    2014-01-01

    Transgenic tomato plants with reduced expression of the sucrose transporter SlSUT2 showed higher efficiency of mycorrhization suggesting a sucrose retrieval function of SlSUT2 from the peri-arbuscular space back into the cell cytoplasm plant cytoplasm thereby limiting mycorrhiza fungal development. Sucrose uptake in colonized root cells requires efficient plasma membrane-targeting of SlSUT2 which is often retained intracellularly in vacuolar vesicles. Protein-protein interaction studies suggested a link between SISUT2 function and components of brassinosteroid biosynthesis and signaling. Indeed, the tomato DWARF mutant dx defective in BR synthesis1 showed significantly reduced mycorrhization parameters.2 The question has been raised whether the impact of brassinosteroids on mycorrhization is a general phenomenon. Here, we include a rice mutant defective in DIM1/DWARF1 involved in BR biosynthesis to investigate the effects on mycorrhization. A model is presented where brassinolides are able to impact mycorrhization by activating SUT2 internalization and inhibiting its role in sucrose retrieval. PMID:25482803

  1. [Effects of arbuscular mycorrhiza fungi (AMF) on the plant growth, fruit yield, and fruit quality of cucumber under salt stress].

    Science.gov (United States)

    Han, Bing; Guo, Shi-Rong; He, Chao-Xing; Yan, Yan; Yu, Xian-Chang

    2012-01-01

    By adopting organic substrate culture, and salt-sensitive cucumber variety 'Jinchun No. 2' was used as test material, this paper studied the effects of inoculating arbuscular mycorrhiza fungi (AMF) on the plant growth, fruit yield, and fruit quality of cucumber under salt stress. AMF-inoculation could effectively promote the plant growth and nutrient uptake, and improve the fruit yield and fruit nutrient quality, compared with ordinary cultivation. Under salt stress, the plant growth was inhibited, and the plant N, P, K, Cu, and Zn contents and K+/Na+ ratio, fruit yield, and fruit soluble protein, total sugar, vitamin C, and nitrate contents decreased, while inoculation with AMF could mitigate the inhibitory effect of salt stress on the plant growth, made the plant N, P, K, Cu, and Zn contents increased by 7.3%, 11.7%, 28.2%, 13.5%, and 9.9%, respectively, and made the plant K+/Na+ ratio, fruit yield, and fruit soluble protein, total sugar, and vitamin C contents have an obvious increase and the fruit nitrate content have a significant decrease. It was suggested that AMF could promote the plant growth and nutrient uptake of cucumber under salt stress, increase the plant salt-tolerance, and improve the fruit yield and its nutrient quality.

  2. Arbuscular mycorrhiza and petroleum-degrading microorganisms enhance phytoremediation of petroleum-contaminated soil.

    Science.gov (United States)

    Alarcón, Alejandro; Davies, Fred T; Autenrieth, Robin L; Zuberer, David A

    2008-01-01

    While plants can phytoremediate soils that are contaminated with petroleum hydrocarbons, adding microbes to remediate contaminated sites with petroleum-degrading microorganisms and arbuscular mycorrhizal fungi (AMF) is not well understood. The phytoremediation of Arabian medium crude oil (ACO) was done with a Lolium multiflorum system inoculated with an AMF (Glomus intraradices) and a mixture of petroleum-degrading microorganisms--the bacterium, Sphingomonas paucimobilis (Sp) and the filamentous fungus, Cunninghamella echinulata (Ce, SpCe)--or with a combination of microorganisms (AMF + SpCe). Based on an earlier study on screening plants for phytoremediation of ACO, L. multiflorum (Italian ryegrass) was selected for its tolerance and rapid growth response (Alarcón, 2006). The plants were exposed to ACO-contaminated soil (6000 mg kg(-1)) for 80 d under greenhouse conditions. A modified Long Ashton Nutrient Solution (LANS) was supplied to all treatments at 30 microg P mL(-1), except for a second, higher P, control treatment at 44 microg P mL(-1). Inoculation with AMF, SpCe, or AMF + SpCe resulted in significantly increased leaf area as well as leaf and pseudostem dry mass as compared to controls at 30 microg P mL(-1). Populations of bacteria grown on a nitrogen-free medium and filamentous fungi increased with AMF + SpCe and SpCe treatments. The average total colonization and arbuscule formation of AMF-inoculated plants in ACO-contaminated soil were 25% and 8%, respectively. No adverse effects were caused by SpCe on AMF colonization. Most importantly, ACO degradation was significantly enhanced by the addition of petroleum-degrading microorganisms and higher fertility controls, as compared to plants at 30 microg P mL(-1). The highest ACO degradation (59%) was observed with AMF + SpCe. The phytoremediation of ACO was also enhanced by single inoculation of AMF or SpCe. The effect of AMF and petroleum-degrading microorganisms on plant growth and ACOdegradation was not

  3. Arbuscular mycorrhiza of Arnica montana under field conditions--conventional and molecular studies.

    Science.gov (United States)

    Ryszka, Przemysław; Błaszkowski, Janusz; Jurkiewicz, Anna; Turnau, Katarzyna

    2010-11-01

    Two distinct populations of Arnica montana, an endangered medicinal plant, were studied under field conditions. The material was investigated using microscopic and molecular methods. The analyzed plants were always found to be mycorrhizal. Nineteen arbuscular mycorrhizal fungal DNA sequences were obtained from the roots. They were related to Glomus Group A, but most did not match any known species. Some showed a degree of similarity to fungi colonizing liverworts. Conventional analysis of spores isolated from soil samples allowed to identify different fungal taxa: Glomus macrocarpum, Glomus mosseae, Acaulospora lacunosa, and Scutellospora dipurpurescens. Their spores were also isolated from trap cultures.

  4. Field inoculation of arbuscular mycorrhiza on maize (Zea mays L. under low inputs: preliminary study on quantitative and qualitative aspects

    Directory of Open Access Journals (Sweden)

    Emilio Sabia

    2015-03-01

    Full Text Available Arbuscular mycorrhizal symbiosis contributes to the sustainability of soil-plant system. A field experiment was conducted to examine the effect of arbuscular mycorrhiza (AM on quantitative and qualitative performance in forage maize (Zea mays L.. Within the project Sviluppo di modelli zootecnici ai fini della sostenibilità (SOS-ZOOT a trial was conducted at the experimental farm of the Agricultural Research Council in Bella (PZ, located in Basilicata region (Southern Italy at 360 m asl, characterised by an annual rainfall of approximately 650 mm. For spring sowing, two plots of 2500 m2 were used, one sown with seeds inoculated with AM (M, 1.0 kg/ha, and the other one with non-inoculated seeds (NM. After 120 days after sowing, when plants showed 30% dry matter, five replicates of 1 m2 per plot were used to estimate dry matter yield (DMY, while half plot was dedicated to the assessment of grain production. For each replicate, three representative plants were considered; each plant was measured for height and was divided into leaves, stem and ear. For each plot, the following constituents were determined: crude protein, ash, ether extract, crude fibre (CF, fractions of fibre [neutral detergent (NDF, acid detergent fibre (ADF and sulphuric acid lignin] and phosphorus (P. Throughout the period of plants’ growth, no herbicides, organic or inorganic fertilisation, and irrigation water were distributed. The preliminary results revealed a significant effect of AM inoculation on forage maize DMY, P content in the whole plant, into the leaves and on the quality of steam. The M thesis showed a significant increase in terms of DMY in comparison with the NM thesis: 21.2 vs 17.9 t/ha (P<0.05. The mycorrhized whole plants [0.22 vs 0.17% dry matter (DM, P<0.05] and leaves (0.14 vs 0.09% DM, P<0.05 showed an increased P content. The stems of M plants showed a content of CF, NDF, ADF and Ash significantly lower compared with NM plants. No significant

  5. Arsenate induces the expression of fungal genes involved in As transport in arbuscular mycorrhiza.

    Science.gov (United States)

    González-Chávez, Ma del Carmen A; Ortega-Larrocea, María del Pilar; Carrillo-González, Rogelio; López-Meyer, Melina; Xoconostle-Cázares, Beatriz; Gomez, Susana K; Harrison, Maria J; Figueroa-López, Alejandro Miguel; Maldonado-Mendoza, Ignacio E

    2011-12-01

    We utilized the two-compartment system to study the effect of arsenic (As) on the expression of the Glomus intraradices high-affinity phosphate transporter GiPT, and the GiArsA gene, a novel protein with a possible putative role as part of an arsenite efflux pump and similar to ArsA ATPase. Our results show that induction of GiPT expression correlates with As(V) uptake in the extra-radical mycelium of G. intraradices. We showed a time-concerted induction of transcript levels first of GiPT, followed by GiArsA, as well as the location of gene expression using laser microdissection of these two genes not only in the extra-radical mycelium but also in arbuscules. This work represents the first report showing the dissection of the molecular players involved in arbuscular mycorrhizal fungus (AMF)-mediated As tolerance in plants, and suggests that tolerance mediated by AMF may be caused by an As exclusion mechanism, where fungal structures such as the extra-radical mycelium and arbuscules may be playing an important role. Our results extend knowledge of the mechanisms underlying As efflux in arbuscular mycorrhizal fungi and mechanisms related to As tolerance. Copyright © 2011 British Mycological Society. All rights reserved.

  6. Can arbuscular mycorrhiza and fertilizer management reduce phosphorus runoff from paddy fields?

    Science.gov (United States)

    Zhang, Shujuan; Wang, Li; Ma, Fang; Zhang, Xue; Li, Zhe; Li, Shiyang; Jiang, Xiaofeng

    2015-07-01

    Our study sought to assess how much phosphorus (P) runoff from paddy fields could be cut down by fertilizer management and inoculation with arbuscular mycorrhizal fungi. A field experiment was conducted in Lalin River basin, in the northeast China: six nitrogen-phosphorus-potassium fertilizer levels were provided (0, 20%, 40%, 60%, 80%, and 100% of the recommended fertilizer supply), with or without inoculation with Glomus mosseae. The volume and concentrations of particle P (PP) and dissolved P (DP) were measured for each runoff during the rice growing season. It was found that the seasonal P runoff, including DP and PP, under the local fertilization was 3.7 kg/ha, with PP, rather than DP, being the main form of P in runoff water. Additionally, the seasonal P runoff dropped only by 8.9% when fertilization decreased by 20%; rice yields decreased with declining fertilization. We also found that inoculation increased rice yields and decreased P runoff at each fertilizer level and these effects were lower under higher fertilization. Conclusively, while rice yields were guaranteed arbuscular mycorrhizal inoculation and fertilizer management would play a key role in reducing P runoff from paddy fields. Copyright © 2015. Published by Elsevier B.V.

  7. The thalloid liverwort Plagiochasma rupestre supports arbuscular mycorrhiza-like symbiosis in vitro.

    Science.gov (United States)

    Silvani, Vanesa Analía; Rothen, Carolina Paola; Rodríguez, María Alejandra; Godeas, Alicia; Fracchia, Sebastián

    2012-12-01

    In the present study, we obtained in vitro dual cultures between the liverwort Plagiochasma rupestre and two arbuscular mycorrhizal (AM) fungi: Glomus intraradices and Glomus clarum. Four agarized culture media were tested for optimal growth of P. rupestre. Also, a description of the symbiotic association is provided. Plagiochasma rupestre gametophytes profusely grew axenically in MM with sucrose, and thalli were successfully subcultured under these growth conditions. Arbuscular mycorrhizal fungal hyphae colonized P. rupestre thalli through rhizoids or by forming appresoria in the ventral thallus cells. Arbuscules, mycelia and structures resembling intrathallic spores or vesicles were developed in the internal parenchymatic cells. The pattern of AM colonization in P. rupestre was very similar to the Paris-type. After 100 days of dual culture, the external mycelia of both AM fungal strains formed thousands of small viable spores, suggesting that P. rupestre in vitro culture could be a valuable tool for studying the biology of both symbiotic partners and conserving AM fungi in in vitro germplasm collections.

  8. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids.

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C; Bruce, Toby J A; Pickett, John A; Johnson, David

    2014-10-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. The sucrose transporter SlSUT2 from tomato interacts with brassinosteroid functioning and affects arbuscular mycorrhiza formation.

    Science.gov (United States)

    Bitterlich, Michael; Krügel, Undine; Boldt-Burisch, Katja; Franken, Philipp; Kühn, Christina

    2014-06-01

    Mycorrhizal plants benefit from the fungal partners by getting better access to soil nutrients. In exchange, the plant supplies carbohydrates to the fungus. The additional carbohydrate demand in mycorrhizal plants was shown to be balanced partially by higher CO2 assimilation and increased C metabolism in shoots and roots. In order to test the role of sucrose transport for fungal development in arbuscular mycorrhizal (AM) tomato, transgenic plants with down-regulated expression of three sucrose transporter genes were analysed. Plants that carried an antisense construct of SlSUT2 (SlSUT2as) repeatedly exhibited increased mycorrhizal colonization and the positive effect of plants to mycorrhiza was abolished. Grafting experiments between transgenic and wild-type rootstocks and scions indicated that mainly the root-specific function of SlSUT2 has an impact on colonization of tomato roots with the AM fungus. Localization of SISUT2 to the periarbuscular membrane indicates a role in back transport of sucrose from the periarbuscular matrix into the plant cell thereby affecting hyphal development. Screening of an expression library for SlSUT2-interacting proteins revealed interactions with candidates involved in brassinosteroid (BR) signaling or biosynthesis. Interaction of these candidates with SlSUT2 was confirmed by bimolecular fluorescence complementation. Tomato mutants defective in BR biosynthesis were analysed with respect to mycorrhizal symbiosis and showed indeed decreased mycorrhization. This finding suggests that BRs affect mycorrhizal infection and colonization. If the inhibitory effect of SlSUT2 on mycorrhizal growth involves components of BR synthesis and of the BR signaling pathway is discussed. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  10. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C.; Bruce, Toby J. A.; Pickett, John A.; Johnson, David

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling. PMID:25200735

  11. Arum-type of arbuscular mycorrhizae, dark septate endophytes and Olpidium spp. in fine roots of container-grown seedlings of Sorbus torminalis (Rosaceae

    Directory of Open Access Journals (Sweden)

    Roman M. Bzdyk

    2016-06-01

    Full Text Available The aim of this study was to determine the mycorrhizal status of nursery seedlings of the wild service tree (Sorbus torminalis, which belongs to the Rosaceae family. Its mycorrhizal associations are still fragmentarily known, and data from the few existing studies indicate that it forms ectomycorrhizal symbiosis (ECM. We analyzed the degree of mycorrhizal colonization of thirty 2-year-old container-grown S. torminalis nursery seedlings, which belonged to three single-tree progenies. The roots were dominated by arbuscular mycorrhizae (AM, with the morphology of the Arum-type containing arbuscules, vesicles and hyphae; however, no ECM structures were found. The degree of root colonization of the analyzed seedlings by AM fungi was 83.6% and did not differ significantly between the three single-tree progenies. In addition to AM, structures of dark septate endophytes (0.7% and sporangia of Olpidium spp. (1.1% were found in wild service tree roots. In agreement with previous studies, we confirmed arbuscular mycorrhizae for S. torminalis. Moreover, this is the first report that roots of this Sorbus species show the Arum-type morphology of AM and are associated with Olpidium species.

  12. Growth and reproductive characteristics of the columnar cactus Stenocereus queretaroensis and their relationships with environmental factors and colonization by arbuscular mycorrhizae.

    Science.gov (United States)

    Pimienta-Barrios, Eulogio; Pimienta-Barrios, Enrique; Salas-Galván, Mariá Eugenia; Zañudo-Hernandez, Julia; Nobel, Park S

    2002-06-01

    Three natural populations of pitayo (Stenocereus queretaroensis (Weber) Buxbaum), a columnar arborescent cactus, were studied in their subtropical environments in western Mexico. All of the sites were characterized by shallow, nutrient-poor soils. Percentage of colonization by arbuscular mycorrhizae (AM) fungi, stem growth, fruit mass, and percentage germination were greater in S. queretaroensis at Autlan, Jalisco (AJ) than at Zacoalco de Torres, Jalisco (ZTJ) or Santa Rosa, Zacatecas (SRZ). The onset of root colonization by arbuscular mycorrhizae during the middle of the summer wet period preceded increases in stem extension rate and stem phosphorus concentration. Based on previous studies of effects of environmental factors on photosynthesis, climatic conditions were more favorable for photosynthesis at AJ than at SRZ and ZTJ, as indicated by the amount of summer rainfall, the amount of light, and the moderate air temperatures that prevailed during the fall and winter seasons. There was a significant positive correlation between stem growth and percentage of total root length colonized by arbuscules of AM fungi for S. queretaroensis at SRZ and AJ, but not at ZTJ. A negative significant correlation was observed between stem growth and maximal and minimal air temperatures at the three study sites. Stem growth was positively related to rainfall only at SRZ, and light was statistically related to stem growth only at ZTJ. Among sites, S. queretaroensis at AJ had the highest carbon gain and greatest AM colonization, creating physiological conditions that led to the highest stem growth, fruit mass and percentage of seed germination.

  13. Arbuscular mycorrhiza alter the concentration of essential oils in oregano (Origanum sp., Lamiaceae).

    Science.gov (United States)

    Khaosaad, T; Vierheilig, H; Nell, M; Zitterl-Eglseer, K; Novak, J

    2006-09-01

    The effect of root colonization by Glomus mosseae on the qualitative and quantitative pattern of essential oils (EO) was determined in three oregano genotypes (Origanum sp.). To exclude a simple P-mediated effect through mycorrhization the effect of P application to plants on the EO accumulation was also tested. In two genotypes the leaf biomass was increased through mycorrhization. Root colonization by the arbuscular mycorrhizal fungus (AMF) did not have any significant effect on the EO composition in oregano; however, in two genotypes the EO concentration significantly increased. As EO levels in P-treated plants were not enhanced, we conclude that the EO increase observed in mycorrhizal oregano plants is not due to an improved P status in mycorrhizal plants, but depends directly on the AMF-oregano plant association.

  14. Arbuscular mycorrhiza improves yield and nutritional properties of onion (Allium cepa).

    Science.gov (United States)

    Rozpądek, Piotr; Rąpała-Kozik, Maria; Wężowicz, Katarzyna; Grandin, Anna; Karlsson, Stefan; Ważny, Rafał; Anielska, Teresa; Turnau, Katarzyna

    2016-10-01

    Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogues and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. A modified staining technique for arbuscular mycorrhiza compatible with molecular probes.

    Science.gov (United States)

    Pitet, M; Camprubí, A; Calvet, C; Estaún, V

    2009-02-01

    The effects of the different steps of the root staining on the arbuscular mycorrhizal (AM) fungal rDNA extraction and amplification have been assessed. The results obtained using molecular techniques are compared with those obtained from fresh, non-stained leek roots. A modified staining procedure that eliminates heating, the use of hydrochloric acid and trypan blue, has been proved to be the most adequate to observe the AM colonisation in different plant species with/without lignified roots allowing at the same time the subsequent rDNA extraction and amplification from the stained roots. The staining technique decreased the sensitivity of the process and a higher number of roots had to be used to obtain enough material for a positive amplification. The extraction and amplification process was reliable up to 3 days after staining. A week after staining, the amplification was not dependable and after 2 weeks there was no amplification from stained material.

  16. Roles of arbuscular mycorrhizas in plant nutrition and growth: new paradigms from cellular to ecosystem scales.

    Science.gov (United States)

    Smith, Sally E; Smith, F Andrew

    2011-01-01

    Root systems of most land plants form arbuscular mycorrhizal (AM) symbioses in the field, and these contribute to nutrient uptake. AM roots have two pathways for nutrient absorption, directly through the root epidermis and root hairs and via AM fungal hyphae into root cortical cells, where arbuscules or hyphal coils provide symbiotic interfaces. New physiological and molecular evidence shows that for phosphorus the mycorrhizal pathway (MP) is operational regardless of plant growth responses (positive or negative). Amounts delivered cannot be determined from plant nutrient contents because when responses are negative the contribution of the direct pathway (DP) is reduced. Nitrogen (N) is also delivered to roots via an MP, but the contribution to total N requirement and the costs to the plant are not clear. The functional interplay between activities of the DP and MP has important implications for consideration of AM symbioses in ecological, agronomic, and evolutionary contexts.

  17. Arbuscular mycorrhizae reducing water loss in maize plants under low temperature stress.

    Science.gov (United States)

    Zhu, Xian Can; Song, Feng Bin; Liu, Tie Dong; Liu, Sheng Qun

    2010-05-01

    Arbuscular mycorrhizal (AM) fungi form mutualistic mycorrhizal symbiotic associations with the roots of approximately 80% of all terrestrial plant species while facilitate the uptake of soil mineral nutrients by plants and in exchange obtain carbohydrates, thus representing a large sink for photosynthetically fixed carbon. Also, AM symbiosis increase plants resistance to abiotic stress such as chilling. In a recent study we reported that AM fungi improve low temperature stress in maize plants via alterations in host water status and photosynthesis. Here, the influence of AM fungus, Glomus etunicatum, on water loss rate and growth of maize plants was studied in pot culture under low temperature stress. The results indicated that low temperature stress significantly decreases the total fresh weight of maize plants, and AM symbiosis alleviate the water loss in leaves of maize plants.

  18. Arbuscular mycorrhizas contribute to phytostabilization of uranium in uranium mining tailings.

    Science.gov (United States)

    Chen, Baodong; Roos, Per; Zhu, Yong-Guan; Jakobsen, Iver

    2008-05-01

    Uranium (U) tailings pose environmental risks and call for proper remediation. In this paper medic and ryegrass plants were used as host plants to examine whether inoculation with an AM fungus, Glomus intraradices, would help phytostabilization of U tailings. The need of amending with uncontaminated soil for supporting plant survival was also examined by mixing soil with U tailing at different mixing ratios. Soil amendment increased plant growth and P uptake. Ryegrass produced a more extensive root system and a greater biomass than medic plants at all mixing ratios. Medic roots were extensively colonized by G. intraradices whereas ryegrass were more sparsely colonized. Plant growth was not improved by mycorrhizas, which, however, improved P nutrition of medic plants. Medic plants contained higher U concentrations and showed higher specific U uptake efficiency compared to ryegrass. In the presence of U tailing, most U had been retained in plant roots, and this distribution pattern was further enhanced by mycorrhizal colonization. The results suggest a role for AM fungi in phytostabilization of U tailings.

  19. Arbuscular mycorrhizas contribute to phytostabilization of uranium in uranium mining tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baodong [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark); Roos, Per [Radiation Research Department, Technical University of Denmark, Riso National Laboratory, DK-4000 Roskilde (Denmark); Zhu Yongguan [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Jakobsen, Iver [Biosystems Department, Riso National Laboratory, Technical University of Denmark, DK-4000 Roskilde (Denmark)], E-mail: iver.jakobsen@risoe.dk

    2008-05-15

    Uranium (U) tailings pose environmental risks and call for proper remediation. In this paper medic and ryegrass plants were used as host plants to examine whether inoculation with an AM fungus, Glomus intraradices, would help phytostabilization of U tailings. The need of amending with uncontaminated soil for supporting plant survival was also examined by mixing soil with U tailing at different mixing ratios. Soil amendment increased plant growth and P uptake. Ryegrass produced a more extensive root system and a greater biomass than medic plants at all mixing ratios. Medic roots were extensively colonized by G. intraradices whereas ryegrass were more sparsely colonized. Plant growth was not improved by mycorrhizas, which, however, improved P nutrition of medic plants. Medic plants contained higher U concentrations and showed higher specific U uptake efficiency compared to ryegrass. In the presence of U tailing, most U had been retained in plant roots, and this distribution pattern was further enhanced by mycorrhizal colonization. The results suggest a role for AM fungi in phytostabilization of U tailings.

  20. Functional analysis of the novel mycorrhiza-specific phosphate transporter AsPT1 and PHT1 family from Astragalus sinicus during the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Xie, Xianan; Huang, Wu; Liu, Fengchuan; Tang, Nianwu; Liu, Yi; Lin, Hui; Zhao, Bin

    2013-05-01

    Arbuscular mycorrhizas contribute significantly to inorganic phosphate (Pi) uptake in plants. Gene networks involved in the regulation and function of the Pht1 family transporters in legume species during AM symbiosis are not fully understood. In order to characterize the six distinct members of Pht1 transporters in mycorrhizal Astragalus sinicus, we combined cellular localization, heterologous functional expression in yeast with expression/subcellular localization studies and reverse genetics approaches in planta. Pht1;1 and Pht1;4 silenced lines were generated to uncover the role of the newly discovered dependence of the AM symbiosis on another phosphate transporter AsPT1 besides AsPT4. These Pht1 transporters are triggered in Pi-starved mycorrhizal roots. AsPT1 and AsPT4 were localized in arbuscule-containing cells of the cortex. The analysis of promoter sequences revealed conserved motifs in both AsPT1 and AsPT4. AsPT1 overexpression showed higher mycorrhization levels than controls for parameters analysed, including abundance of arbuscules. By contrast, knockdown of AsPT1 by RNA interference led to degenerating or dead arbuscule phenotypes identical to that of AsPT4 silencing lines. AsPT4 but not AsPT1 is required for symbiotic Pi uptake. These results suggest that both, AsPT1 and AsPT4, are required for the AM symbiosis, most importantly, AsPT1 may serve as a novel symbiotic transporter for AM development. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  1. Regulation of root morphogenesis in arbuscular mycorrhizae: what role do fungal exudates, phosphate, sugars and hormones play in lateral root formation?

    Science.gov (United States)

    Fusconi, Anna

    2014-01-01

    Arbuscular mycorrhizae (AMs) form a widespread root-fungus symbiosis that improves plant phosphate (Pi) acquisition and modifies the physiology and development of host plants. Increased branching is recognized as a general feature of AM roots, and has been interpreted as a means of increasing suitable sites for colonization. Fungal exudates, which are involved in the dialogue between AM fungi and their host during the pre-colonization phase, play a well-documented role in lateral root (LR) formation. In addition, the increased Pi content of AM plants, in relation to Pi-starved controls, as well as changes in the delivery of carbohydrates to the roots and modulation of phytohormone concentration, transport and sensitivity, are probably involved in increasing root system branching. This review discusses the possible causes of increased branching in AM plants. The differential root responses to Pi, sugars and hormones of potential AM host species are also highlighted and discussed in comparison with those of the non-host Arabidopsis thaliana. Fungal exudates are probably the main compounds regulating AM root morphogenesis during the first colonization steps, while a complex network of interactions governs root development in established AMs. Colonization and high Pi act synergistically to increase root branching, and sugar transport towards the arbusculated cells may contribute to LR formation. In addition, AM colonization and high Pi generally increase auxin and cytokinin and decrease ethylene and strigolactone levels. With the exception of cytokinins, which seem to regulate mainly the root:shoot biomass ratio, these hormones play a leading role in governing root morphogenesis, with strigolactones and ethylene blocking LR formation in the non-colonized, Pi-starved plants, and auxin inducing them in colonized plants, or in plants grown under high Pi conditions.

  2. Improvement of Arbuscular Mycorrhiza Development by Inoculation of Soil with Phosphate-Solubilizing Rhizobacteria To Improve Rock Phosphate Bioavailability ((sup32)P) and Nutrient Cycling

    Science.gov (United States)

    Toro, M.; Azcon, R.; Barea, J.

    1997-01-01

    The interactive effect of phosphate-solubilizing bacteria and arbuscular mycorrhizal (AM) fungi on plant use of soil P sources of low bioavailability (endogenous or added as rock phosphate [RP] material) was evaluated by using soil microcosms which integrated (sup32)P isotopic dilution techniques. The microbial inocula consisted of the AM fungus Glomus intraradices and two phosphate-solubilizing rhizobacterial isolates: Enterobacter sp. and Bacillus subtilis. These rhizobacteria behaved as "mycorrhiza helper bacteria" promoting establishment of both the indigenous and the introduced AM endophytes despite a gradual decrease in bacterial population size, which dropped from 10(sup7) at planting to 10(sup3) CFU g(sup-1) of dry rhizosphere soil at harvest. Dual inoculation with G. intraradices and B. subtilis significantly increased biomass and N and P accumulation in plant tissues. Regardless of the rhizobacterium strain and of the addition of RP, AM plants displayed lower specific activity ((sup32)P/(sup31)P) than their comparable controls, suggesting that the plants used P sources not available in their absence. The inoculated rhizobacteria may have released phosphate ions ((sup31)P), either from the added RP or from the less-available indigenous P sources, which were effectively taken up by the external AM mycelium. Soluble Ca deficiency in the test soil may have benefited P solubilization. At least 75% of the P in dually inoculated plants derived from the added RP. It appears that these mycorrhizosphere interactions between bacterial and fungal plant associates contributed to the biogeochemical P cycling, thus promoting a sustainable nutrient supply to plants. PMID:16535730

  3. Improvement of Arbuscular Mycorrhiza Development by Inoculation of Soil with Phosphate-Solubilizing Rhizobacteria To Improve Rock Phosphate Bioavailability ((sup32)P) and Nutrient Cycling.

    Science.gov (United States)

    Toro, M; Azcon, R; Barea, J

    1997-11-01

    The interactive effect of phosphate-solubilizing bacteria and arbuscular mycorrhizal (AM) fungi on plant use of soil P sources of low bioavailability (endogenous or added as rock phosphate [RP] material) was evaluated by using soil microcosms which integrated (sup32)P isotopic dilution techniques. The microbial inocula consisted of the AM fungus Glomus intraradices and two phosphate-solubilizing rhizobacterial isolates: Enterobacter sp. and Bacillus subtilis. These rhizobacteria behaved as "mycorrhiza helper bacteria" promoting establishment of both the indigenous and the introduced AM endophytes despite a gradual decrease in bacterial population size, which dropped from 10(sup7) at planting to 10(sup3) CFU g(sup-1) of dry rhizosphere soil at harvest. Dual inoculation with G. intraradices and B. subtilis significantly increased biomass and N and P accumulation in plant tissues. Regardless of the rhizobacterium strain and of the addition of RP, AM plants displayed lower specific activity ((sup32)P/(sup31)P) than their comparable controls, suggesting that the plants used P sources not available in their absence. The inoculated rhizobacteria may have released phosphate ions ((sup31)P), either from the added RP or from the less-available indigenous P sources, which were effectively taken up by the external AM mycelium. Soluble Ca deficiency in the test soil may have benefited P solubilization. At least 75% of the P in dually inoculated plants derived from the added RP. It appears that these mycorrhizosphere interactions between bacterial and fungal plant associates contributed to the biogeochemical P cycling, thus promoting a sustainable nutrient supply to plants.

  4. Influence of arbuscular mycorrhiza on organic solutes in maize leaves under salt stress.

    Science.gov (United States)

    Sheng, Min; Tang, Ming; Zhang, Fengfeng; Huang, Yanhui

    2011-07-01

    A pot experiment was conducted to examine the effect of the arbuscular mycorrhizal (AM) fungus, Glomus mosseae, on plant biomass and organic solute accumulation in maize leaves. Maize plants were grown in sand and soil mixture with three NaCl levels (0, 0.5, and 1.0 g kg(-1) dry substrate) for 55 days, after 15 days of establishment under non-saline conditions. At all salinity levels, mycorrhizal plants had higher biomass and higher accumulation of organic solutes in leaves, which were dominated by soluble sugars, reducing sugars, soluble protein, and organic acids in both mycorrhizal and non-mycorrhizal plants. The relative abundance of free amino acids and proline in total organic solutes was lower in mycorrhizal than in non-mycorrhizal plants, while that of reducing sugars was higher. In addition, the AM symbiosis raised the concentrations of soluble sugars, reducing sugars, soluble protein, total organic acids, oxalic acid, fumaric acid, acetic acid, malic acid, and citric acid and decreased the concentrations of total free amino acids, proline, formic acid, and succinic acid in maize leaves. In mycorrhizal plants, the dominant organic acid was oxalic acid, while in non-mycorrhizal plants, the dominant organic acid was succinic acid. All the results presented here indicate that the accumulation of organic solutes in leaves is a specific physiological response of maize plants to the AM symbiosis, which could mitigate the negative impact of soil salinity on plant productivity.

  5. 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.

  6. Competitive interactions are mediated in a sex-specific manner by arbuscular mycorrhiza in Antennaria dioica.

    Science.gov (United States)

    Varga, S; Vega-Frutis, R; Kytöviita, M-M

    2017-03-01

    Plants usually interact with other plants, and the outcome of such interaction ranges from facilitation to competition depending on the identity of the plants, including their sexual expression. Arbuscular mycorrhizal (AM) fungi have been shown to modify competitive interactions in plants. However, few studies have evaluated how AM fungi influence plant intraspecific and interspecific interactions in dioecious species. The competitive abilities of female and male plants of Antennaria dioica were examined in a greenhouse experiment. Females and males were grown in the following competitive settings: (i) without competition, (ii) with intrasexual competition, (iii) with intersexual competition, and (iv) with interspecific competition by Hieracium pilosella - a plant with similar characteristics to A. dioica. Half of the pots were grown with Claroideoglomus claroideum, an AM fungus isolated from the same habitat as the plant material. We evaluated plant survival, growth, flowering phenology, and production of AM fungal structures. Plant survival was unaffected by competition or AM fungi. Competition and the presence of AM fungi reduced plant biomass. However, the sexes responded differently to the interaction between fungal and competition treatments. Both intra- and interspecific competition results were sex-specific, and in general, female performance was reduced by AM colonization. Plant competition or sex did not affect the intraradical structures, extraradical hyphae, or spore production of the AM fungus. These findings suggest that plant sexual differences affect fundamental processes such as competitive ability and symbiotic relationships with AM fungi. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Arbuscular mycorrhiza affects nickel translocation and expression of ABC transporter and metallothionein genes in Festuca arundinacea.

    Science.gov (United States)

    Shabani, Leila; Sabzalian, Mohammad R; Mostafavi pour, Sodabeh

    2016-01-01

    Mycorrhizal fungi are key microorganisms for enhancing phytoremediation of soils contaminated with heavy metals. In this study, the effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae (=Glomus mosseae) on physiological and molecular mechanisms involved in the nickel (Ni) tolerance of tall fescue (Festuca arundinacea = Schedonorus arundinaceus) were investigated. Nickel addition had a pronounced negative effect on tall fescue growth and photosynthetic pigment contents, as well as on AMF colonization. Phosphorus content increased markedly in mycorrhizal plants (M) compared to non-inoculated (NM) ones. However, no significant difference was observed in root carbohydrate content between AMF-inoculated and non-inoculated plants. For both M and NM plants, Ni concentrations in shoots and roots increased according to the addition of the metal into soil, but inoculation with F. mosseae led to significantly lower Ni translocation from roots to the aboveground parts compared to non-inoculated plants. ABC transporter and metallothionein transcripts accumulated to considerably higher levels in tall fescue plants colonized by F. mosseae than in the corresponding non-mycorrhizal plants. These results highlight the importance of mycorrhizal colonization in alleviating Ni-induced stress by reducing Ni transport from roots to shoots of tall fescue plants.

  8. Arbuscular mycorrhiza differentially affects synthesis of essential oils in coriander and dill.

    Science.gov (United States)

    Rydlová, Jana; Jelínková, Marcela; Dušek, Karel; Dušková, Elena; Vosátka, Miroslav; Püschel, David

    2016-02-01

    Research on the role of arbuscular mycorrhizal fungi (AMF) in the synthesis of essential oils (EOs) by aromatic plants has seldom been conducted in field-relevant conditions, and then, only limited spectra of EO constituents have been analyzed. The effect was investigated of inoculation with AMF on the synthesis of a wide range of EO in two aromatic species, coriander (Coriandrum sativum) and dill (Anethum graveolens), in a garden experiment under outdoor conditions. Plants were grown in 4-l pots filled with soil, which was either γ-irradiated (eliminating native AMF) or left non-sterile (containing native AMF), and inoculated or not with an isolate of Rhizophagus irregularis. AMF inoculation significantly stimulated EO synthesis in both plant species. EO synthesis (total EO and several individual constituents) was increased in dill in all mycorrhizal treatments (containing native and/or inoculated AMF) compared to non-mycorrhizal plants. In contrast, EO concentrations in coriander (total EO and most constituents) were increased only in the treatment combining both inoculated and native AMF. A clear positive effect of AMF on EO synthesis was found for both aromatic plants, which was, however, specific for each plant species and modified by the pool of AMF present in the soil.

  9. Arbuscular mycorrhiza enhance the rate of litter decomposition while inhibiting soil microbial community development.

    Science.gov (United States)

    Gui, Heng; Hyde, Kevin; Xu, Jianchu; Mortimer, Peter

    2017-02-08

    Although there is a growing amount of evidence that arbuscular mycorrhizal fungi (AMF) influence the decomposition process, the extent of their involvement remains unclear. Therefore, given this knowledge gap, our aim was to test how AMF influence the soil decomposer communities. Dual compartment microcosms, where AMF (Glomus mosseae) were either allowed access (AM+) to or excluded (AM-) from forest soil compartments containing litterbags (leaf litter from Calophyllum polyanthum) were used. The experiment ran for six months, with destructive harvests at 0, 90, 120, 150, and 180 days. For each harvest we measured AMF colonization, soil nutrients, litter mass loss, and microbial biomass (using phospholipid fatty acid analysis (PLFA)). AMF significantly enhanced litter decomposition in the first 5 months, whilst delaying the development of total microbial biomass (represented by total PLFA) from T150 to T180. A significant decline in soil available N was observed through the course of the experiment for both treatments. This study shows that AMF have the capacity to interact with soil microbial communities and inhibit the development of fungal and bacterial groups in the soil at the later stage of the litter decomposition (180 days), whilst enhancing the rates of decomposition.

  10. [Effect of arbuscular mycorrhizae on growth, heavy metal uptake and accumulation of Zenia insignis Chun seedlings].

    Science.gov (United States)

    Li, Xia; Peng, Xia-Wei; Wu, Song-Lin; Li, Zhi-Ru; Feng, Hong-Mei; Jiang, Ze-Ping

    2014-08-01

    To solve the trace metal pollution of a Pd/Zn mine in Hunan province, a greenhouse pot experiment was conducted to investigate the effect of two arbuscular mycorrhizal fungi, Glomus mosseae (Gm) and Glomus intraradices (Gi), on the growth, heavy metal uptake and accumulation of Zenia insignis Chun, the pioneer plant there. The results showed that symbiotic associations were successfully established between the two isolates and Z. insignis in heavy metal contaminated soil. AM fungi improved P absorption, biomass and changed heavy metal uptake and distribution of Z. insignis. AM fungi-inoculated plants had significantly lower Fe, Cu, Zn, Pd concentrations and higher Fe, Cu, Zn, Pd accumulation than non-inoculated plants. However, Gm and Gi showed different mycorrhizal effects on the distribution of heavy metal in hosts, depending on the species of heavy metal. Gi-inoculated Z. insignis showed significantly lower TF values of Fe, Zn, Pd than Gm and non-inoculated plants, while both strains had no effect on TF value of Cu, which indicated that Gi enhanced trace metal accumulation in root system, playing a filtering/sequestering role in the presence of trace metals. The overall results demonstrated that AM fungi had positive effect on Z. insignis in enhancing the ability to adapt the heavy metal contaminated soil and played potential role in the revegetation of heavy metal contaminated soil. But in practical application, the combination of AM, hosts and heavy metal should be considered.

  11. [Infection progress of arbuscular mycorrhizae on tissue-cultured plantlets of Pinellia ternata].

    Science.gov (United States)

    Shen, Xuelian; Guo, Qiaosheng; Liu, Zuoyi; Zhu, Guosheng; Liu, Yongxiang

    2011-01-01

    To study the Arbuscular mycorrhizal (AM) formation progress and infection characteristics between tissue culture plantlets of Pinellia ternata and Glomus mosseae. The tissue culture plantlets of P. ternata were inoculated with G. mosseae, the formation of AM were sampled and observed with microscopy by staining. The hyphae of G. mosseae began to penetrate the root epidermis after 10 days of inoculation. Lots of intracellular hyphae formed in cortex cells at the 15th day. Arbuscules started to form and there were some hyphae on the root at the 20th day. At the 25th day, many arbuscules formed and most as Arum type. Some arbuscles started to disintegrate at the 30th day, and a few of vesicles occurred. Lots of spores formed after 35 days. At the 40th day, some vesicles began to decline. The hand section showed that the intercellular hyphae gradually formed in intercellular space, and the hyphae branched in cortex cells and occupied most cell lumen finally. It is expounded that P. ternata and G. mosseae could recognize each other quickly and form a symbiont system.

  12. Arbuscular mycorrhizas in coastal sand dunes of the Paraguaná Peninsula, Venezuela.

    Science.gov (United States)

    Alarcón, C; Cuenca, G

    2005-12-01

    Arbuscular mycorrhizal colonization was measured in the most abundant plant species of the Paraguaná Peninsula, northwestern Venezuela. These plant species included: Acacia tortuosa, Argusia gnaphalodes, Croton punctatus, Croton rhamnifolius, Egletes prostrata, Melochia tomentosa, Panicum vaginatum, Scaevola plumieri, Sporobolus virginicus, Suriana maritima, Leptothrium rigidum, and Fimbristylis cymosa. Mycorrhizal colonization was assessed using the Trouvelot et al. (1986) method that allows for simultaneous evaluation of frequency of colonization (%F), intensity of colonization (%M), and the proportion of arbuscules (%A) and vesicles (%V) present in the roots. Average frequency of colonization was 69%. The highest frequency of colonization was around 92% in C. rhamnifolius and A. tortuosa; in the other species, it varied from 49 to 86%. L. rigidum and F. cymosa were considered nonmycorrhizal because its colonization was very scarce and at all times appeared without arbuscules. Average intensity of colonization was 7%. The highest intensity of colonization was 18% in C. rhamnifolius. In the other species, it varied from 3 to 15%. Paspalum vaginatum, A. gnaphalodes, M. tomentosa, and S. maritima had their fungal structures tightly packed in modified little ovoid roots. In general, frequency of AM colonization was high and similar to those reported for other tropical ecosystems, whereas the intensity of AM colonization was low and similar to values obtained in analogous studies in disturbed ecosystems.

  13. The role of arbuscular mycorrhizas in decreasing aluminium phytotoxicity in acidic soils: a review.

    Science.gov (United States)

    Seguel, Alex; Cumming, Jonathan R; Klugh-Stewart, Katrina; Cornejo, Pablo; Borie, Fernando

    2013-04-01

    Soil acidity is an impediment to agricultural production on a significant portion of arable land worldwide. Low productivity of these soils is mainly due to nutrient limitation and the presence of high levels of aluminium (Al), which causes deleterious effects on plant physiology and growth. In response to acidic soil stress, plants have evolved various mechanisms to tolerate high concentrations of Al in the soil solution. These strategies for Al detoxification include mechanisms that reduce the activity of Al3+ and its toxicity, either externally through exudation of Al-chelating compounds such as organic acids into the rhizosphere or internally through the accumulation of Al-organic acid complexes sequestered within plant cells. Additionally, root colonization by symbiotic arbuscular mycorrhizal (AM) fungi increases plant resistance to acidity and phytotoxic levels of Al in the soil environment. In this review, the role of the AM symbiosis in increasing the Al resistance of plants in natural and agricultural ecosystems under phytotoxic conditions of Al is discussed. Mechanisms of Al resistance induced by AM fungi in host plants and variation in resistance among AM fungi that contribute to detoxifying Al in the rhizosphere environment are considered with respect to altering Al bioavailability.

  14. Diversity and persistence of arbuscular mycorrhizas in a low-Arctic meadow habitat.

    Science.gov (United States)

    Pietikäinen, Anne; Kytöviita, Minna-Maarit; Husband, Rebecca; Young, J Peter W

    2007-01-01

    Little is known about the ecology and diversity of arbuscular mycorrhizal (AM) fungi in Arctic ecosystems. Here, the diversity and composition of the AM fungal community and its response to host plant community composition were studied in a low-Arctic meadow habitat. The natural vegetation in two low-Arctic meadow sites was manipulated. Plots with natural vegetation, monoculture and no vegetation were established. Seeds of Solidago virgaurea were sown into the plots and the AM fungal community in the seedling roots was analysed using the terminal restriction fragment length polymorphism (T-RFLP) method. The vegetation manipulation treatments affected the community composition but not the diversity of AM fungi found in S. virgaurea roots. The diversity of AM fungi was higher in S. virgaurea roots in the site with naturally higher plant species diversity. These results show that AM fungi in low-Arctic meadows are able to survive for a period of 2 yr without a host plant. This ability buffers the AM fungal community against short-term changes in host plant community composition and diversity.

  15. Transcriptome Profiling of Lotus japonicus Roots During Arbuscular Mycorrhiza Development and Comparison with that of Nodulation

    Science.gov (United States)

    Deguchi, Yuichi; Banba, Mari; Shimoda, Yoshikazu; Chechetka, Svetlana A.; Suzuri, Ryota; Okusako, Yasuhiro; Ooki, Yasuhiro; Toyokura, Koichi; Suzuki, Akihiro; Uchiumi, Toshiki; Higashi, Shiro; Abe, Mikiko; Kouchi, Hiroshi; Izui, Katsura; Hata, Shingo

    2007-01-01

    Abstract To better understand the molecular responses of plants to arbuscular mycorrhizal (AM) fungi, we analyzed the differential gene expression patterns of Lotus japonicus, a model legume, with the aid of a large-scale cDNA macroarray. Experiments were carried out considering the effects of contaminating microorganisms in the soil inoculants. When the colonization by AM fungi, i.e. Glomus mosseae and Gigaspora margarita, was well established, four cysteine protease genes were induced. In situ hybridization revealed that these cysteine protease genes were specifically expressed in arbuscule-containing inner cortical cells of AM roots. On the other hand, phenylpropanoid biosynthesis-related genes for phenylalanine ammonia-lyase (PAL), chalcone synthase, etc. were repressed in the later stage, although they were moderately up-regulated on the initial association with the AM fungus. Real-time RT–PCR experiments supported the array experiments. To further confirm the characteristic expression, a PAL promoter was fused with a reporter gene and introduced into L. japonicus, and then the transformants were grown with a commercial inoculum of G. mosseae. The reporter activity was augmented throughout the roots due to the presence of contaminating microorganisms in the inoculum. Interestingly, G. mosseae only colonized where the reporter activity was low. Comparison of the transcriptome profiles of AM roots and nitrogen-fixing root nodules formed with Mesorhizobium loti indicated that the PAL genes and other phenylpropanoid biosynthesis-related genes were similarly repressed in the two organs. PMID:17634281

  16. Insight into the role of grafting and arbuscular mycorrhiza on cadmium stress tolerance in tomato.

    Science.gov (United States)

    Kumar, Pradeep; Lucini, Luigi; Rouphael, Youssef; Cardarelli, Mariateresa; Kalunke, Raviraj M; Colla, Giuseppe

    2015-01-01

    Physiological, biochemical, metabolite changes, and gene expression analysis of greenhouse tomato (Solanum lycopersicum L.) were investigated in two grafting combinations (self-grafted 'Ikram' and 'Ikram' grafted onto interspecific hybrid rootstock `Maxifort'), with and without arbuscular mycorrhizal (AM), exposed to 0 and 25 μM Cd. Tomato plants responded to moderate Cadmium (Cd) concentration by decreasing yield and crop growth parameters due to the accumulation of Cd in leaf tissue, inhibition of the PS II activity, reduced nutrients translocation, and also to the oxidative stress as evidenced by enhanced hydrogen peroxide (H2O2) generation, ion leakage, and lipid peroxidation. AM inoculation significantly enhanced the metal concentration in shoots and reduced growth and yield. The Ikram/Maxifort combination induced higher antioxidant enzymes, higher accumulation of proline and reduction of lipid peroxidation products. This suggests that the use of Maxifort rootstock in tomato has a high reactive oxygen species scavenging activity since lower H2O2 concentrations were observed in the presence of Cd. The higher crop performance of Ikram/Maxifort in comparison to Ikram/Ikram combination was also due to the improved nutritional status (higher P, K, Ca, Fe, Mn, and Zn) and increased availability of metabolites involved in cadmium tolerance (phytochelatin PC2, fructans, and inulins). The up-regulation of LeNRAMP3 gene in leaf of Ikram/Maxifort could explain the better nutritional status of interspecific grafting combination (higher Fe, Mn, and Zn).

  17. Insight into the role of grafting and arbuscular mycorrhiza on cadmium stress tolerance in tomato

    Directory of Open Access Journals (Sweden)

    Pradeep eKumar

    2015-06-01

    Full Text Available Physiological, biochemical, metabolite changes and gene expression analysis of greenhouse tomato (Solanum lycopersicumL. were investigated in two grafting combinations (self-grafted ‘Ikram’ and ‘Ikram’ grafted onto interspecific hybrid rootstock ‘Maxifort’, with and without arbuscular mycorrhizal (AM, exposed to 0 and 25 µM Cd. Tomato plants responded to moderate Cd concentration by decreasing yield and crop growth parameters due to the accumulation of Cd in leaf tissue, inhibition of the PS II activity, reduced nutrients translocation, and also to the oxidative stress as evidenced by enhanced hydrogen peroxide (H2O2 generation, ion leakage and lipid peroxidation. AM inoculation significantly enhanced the metal concentration in shoots and reduced growth and yield. The Ikram/Maxifort combination induced higher antioxidant enzymes, higher accumulation of proline and reduction of lipid peroxidation products. This suggests that the use of Maxifort rootstock in tomato has a high reactive oxygen species scavenging activity since lower H2O2 concentrations were observed in the presence of Cd. The higher crop performance of Ikram/Maxifort in comparison to Ikram/Ikram combination was also due to the improved nutritional status (higher P, K, Ca, Fe, Mn, and Zn and increased availability of metabolites involved in cadmium tolerance (phytochelatin PC2 and fructans inulins. The up-regulation of LeNRAMP3 gene in leaf of Ikram/Maxifort could explain the better nutritional status of interspecific grafting combination (higher Fe, Mn, and Zn.

  18. DIVERSITY OF TUBER CROPS AND ARBUSCULAR MYCORRHIZAE FUNGI (AMF UNDER COMMUNITY FOREST STAND IN SOUTH SULAWESI

    Directory of Open Access Journals (Sweden)

    Retno Prayudyaningsih

    2015-05-01

    Full Text Available Implementation of agroforestry system in community forest that incorporate local species Vitex cofassus (bitti, Toona sinensis (suren, Tectona grandis (teak and Aleurites moluccana (candlenut with seasonal crops such as tuber crops would create opportunities for local  people to improve the economic and food security. Tuber crops as the understory could be expected to reduce the rate of soil erosion and expand habitat of beneficia soil microorganisms such as arbuscular mycorrhizal fungi (AMF. The research aims to determine the diversity of tuber crops and AMF in the rhizosphere of tuber crops grown under community forest stands of bitti, suren, teak and candlelnut in South Sulawesi. Results showed that (1 there are 12 kinds of tuber crops that grow under community forest stands in which the 7 types are as alternative food sources, (2 Amorphophallus campanulatus (iles-iles/suweg and Xanthosoma violaceum (kimpul are species of tuber crops that is found growing under all of the commnunity forest stands, (3 all kinds of tuber crops that grow under the community forest stand associated with AMF, in which there are 3 AMF genus i.e Glomus sp. Acaulospora sp. and Gigaspora sp.with low spore density.

  19. Arbuscular mycorrhiza enhance the rate of litter decomposition while inhibiting soil microbial community development

    Science.gov (United States)

    Gui, Heng; Hyde, Kevin; Xu, Jianchu; Mortimer, Peter

    2017-01-01

    Although there is a growing amount of evidence that arbuscular mycorrhizal fungi (AMF) influence the decomposition process, the extent of their involvement remains unclear. Therefore, given this knowledge gap, our aim was to test how AMF influence the soil decomposer communities. Dual compartment microcosms, where AMF (Glomus mosseae) were either allowed access (AM+) to or excluded (AM−) from forest soil compartments containing litterbags (leaf litter from Calophyllum polyanthum) were used. The experiment ran for six months, with destructive harvests at 0, 90, 120, 150, and 180 days. For each harvest we measured AMF colonization, soil nutrients, litter mass loss, and microbial biomass (using phospholipid fatty acid analysis (PLFA)). AMF significantly enhanced litter decomposition in the first 5 months, whilst delaying the development of total microbial biomass (represented by total PLFA) from T150 to T180. A significant decline in soil available N was observed through the course of the experiment for both treatments. This study shows that AMF have the capacity to interact with soil microbial communities and inhibit the development of fungal and bacterial groups in the soil at the later stage of the litter decomposition (180 days), whilst enhancing the rates of decomposition. PMID:28176855

  20. 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.

  1. The influence of arbuscular mycorrhizae and light on Wisconsin (USA) sand savanna understories 2. Plant competition.

    Science.gov (United States)

    Landis, Frank C; Gargas, Andrea; Givnish, Thomas J

    2005-11-01

    Wisconsin (USA) oak savannas are endangered plant communities that have remarkably high plant species diversity. To investigate factors underlying this richness, we experimentally investigated the potentially interacting effects of light gradients and arbuscular mycorrhizal fungi (AMF) on plant competition in the greenhouse, using a fully randomized block design. We used four plant species, soil, and AMF from a remnant sand savanna, under two light and five AMF treatments. Plants were grown four per pot under two competition treatments (either one or four species per pot) for 20 weeks. Using ANOVA, we found that all species showed significant treatment effects on total and shoot biomass, primarily due to differences in competition and light, less to AMF. However, effects were the opposite of predictions. Putatively mycorrhizal plants showed neutral to negative responses to AMF, and a nonmycorrhizal species outcompeted AMF species in infected pots. We concluded that our experimental setup of small pots, sandy soil, and long growing period had induced parasitism by the AMF on susceptible hosts. This unexpected result is consistent with field data from the sand savanna, and may help explain how nonmycorrhizal plants can compete successfully with AMF species in established, species-rich communities.

  2. Identification of arbuscular mycorrhiza (AM-responsive microRNAs in tomato

    Directory of Open Access Journals (Sweden)

    Ping eWu

    2016-03-01

    Full Text Available A majority of land plants can form symbiosis with arbuscular mycorrhizal (AM fungi. MicroRNAs (miRNAs have been implicated to regulate this process in legumes, but their involvement in non-legume species is largely unknown. In this study, by performing deep sequencing of sRNA libraries in tomato roots and comparing with tomato genome, a total of 700 potential miRNAs were predicted, among them, 187 are known plant miRNAs that have been previously deposited in miRBase. Unlike the profiles in other plants such as rice and Arabidopsis, a large proportion of predicted tomato miRNAs was 24 nt in length. A similar pattern was observed in the potato genome but not in tobacco, indicating a Solanum genus-specific expansion of 24-nt miRNAs. About 40% identified tomato miRNAs showed significantly altered expressions upon Rhizophagus irregularis inoculation, suggesting the potential roles of these novel miRNAs in AM symbiosis. The differential expression of five known and six novel miRNAs were further validated using qPCR analysis. Interestingly, three up-regulated known tomato miRNAs belong to a known miR171 family, a member of which has been reported in Medicago truncatula to regulate AM symbiosis. Thus, the miR171 family likely regulates AM symbiosis conservatively across different plant lineages. More than 1000 genes targeted by potential AM-responsive miRNAs were provided and their roles in AM symbiosis are worth further exploring.

  3. Arbuscular mycorrhiza detoxifying response against arsenic and pathogenic fungus in soybean.

    Science.gov (United States)

    Spagnoletti, Federico N; Balestrasse, Karina; Lavado, Raúl S; Giacometti, Romina

    2016-11-01

    Uptake of Arsenic (As) in plant tissues can affect metabolism, causing physiological disorders, even death. As toxicity, but also pathogen infections trigger a generalised stress response called oxidative stress; however knowledge on the response of soybean (Glycine max L.) under multiple stressors is limited so far. Arbuscular mycorrhizal fungi (AMF) enhance the tolerance of host plants to abiotic and biotic stress. Thus, we investigated the effects of the AMF Rhizophagus intraradices on soybean grown in As-contaminated soils as well as in the presence of the pathogen Macrophomina phaseolina (charcoal rot of the stem). Plant parameters and degree of mycorrhizal colonization under the different assessed treatments were analyzed. Content of As in roots and leaves was quantified. Increasing As level in the soil stopped plant growth, but promoted plant As uptake. Inoculation of soybean plants with M. phaseolina accentuated As effect at all physiological levels. In the presence of mycorrhizal symbiosis biomass dramatically increased, and significantly reduced the As concentration in plant tissues. Mycorrhization decreased oxidative damage in the presence of both As and the pathogen. Furthermore, transcription analysis revealed that the high-affinity phosphate transporter from R. intraradices RiPT and the gene encoding a putative arsenic efflux pump RiArsA were up-regulated under higher As doses. These results suggest that R. intraradices is most likely to get involved in the defense response against M. phaseolina, but also in the reduction of arsenate to arsenite as a possible detoxification mechanism in AMF associations in soybean. R. intraradices actively participates in the soybean antioxidant defense response against arsenic stress and M. phaseolina infection. Copyright © 2016. Published by Elsevier Inc.

  4. Lights Off for Arbuscular Mycorrhiza: On Its Symbiotic Functioning under Light Deprivation

    Science.gov (United States)

    Konvalinková, Tereza; Jansa, Jan

    2016-01-01

    Plants are often exposed to shade over different time scales and this may substantially affect not only their own growth, but also development and functioning of the energetically dependent organisms. Among those, the root symbionts such as arbuscular mycorrhizal (AM) fungi and rhizobia represent particularly important cases—on the one hand, they consume a significant share of plant carbon (C) budget and, on the other, they generate a number of important nutritional feedbacks on their plant hosts, often resulting in a net positive effect on their host growth and/or fitness. Here we discuss our previous results comparing mycorrhizal performance under different intensities and durations of shade (Konvalinková et al., 2015) in a broader context of previously published literature. Additionally, we review publicly available knowledge on the root colonization and mycorrhizal growth responses in AM plants under light deprivation. Experimental evidence shows that sudden and intensive decrease of light availability to a mycorrhizal plant triggers rapid deactivation of phosphorus transfer from the AM fungus to the plant already within a few days, implying active and rapid response of the AM fungus to the energetic status of its plant host. When AM plants are exposed to intensive shading on longer time scales (weeks to months), positive mycorrhizal growth responses (MGR) are often decreasing and may eventually become negative. This is most likely due to the high C cost of the symbiosis relative to the C availability, and failure of plants to fully compensate for the fungal C demand under low light. Root colonization by AM fungi often declines under low light intensities, although the active role of plants in regulating the extent of root colonization has not yet been unequivocally demonstrated. Quantitative information on the rates and dynamics of C transfer from the plant to the fungus is mostly missing, as is the knowledge on the involved molecular mechanisms. Therefore

  5. CERBERUS and NSP1 of Lotus japonicus are common symbiosis genes that modulate arbuscular mycorrhiza development.

    Science.gov (United States)

    Takeda, Naoya; Tsuzuki, Syusaku; Suzaki, Takuya; Parniske, Martin; Kawaguchi, Masayoshi

    2013-10-01

    Arbuscular mycorrhizal symbiosis (AMS) and root nodule symbiosis (RNS) are mutualistic plant-microbe interactions that confer nutritional benefits to both partners. Leguminous plants possess a common genetic system for intracellular symbiosis with AM fungi and with rhizobia. Here we show that CERBERUS and NSP1, which respectively encode an E3 ubiquitin ligase and a GRAS transcriptional regulator and which have previously only been implicated in RNS, are involved in AM fungal infection in Lotus japonicus. Hyphal elongation along the longitudinal axis of the root was reduced in the cerberus mutant, giving rise to a lower colonization level. Knockout of NSP1 decreased the frequency of plants colonized by AM fungi or rhizobia. CERBERUS and NSP1 showed different patterns of expression in response to infection with symbiotic microbes. A low constitutive level of CERBERUS expression was observed in the root and an increased level of NSP1 expression was detected in arbuscule-containing cells. Induction of AM marker gene was triggered in both cerberus and nsp1 mutants by infection with symbiotic microbes; however, the mutants showed a weaker induction of marker gene expression than the wild type, mirroring their lower level of colonization. The common symbiosis genes are believed to act in an early signaling pathway for recognition of symbionts and for triggering early symbiotic responses. Our quantitative analysis of symbiotic phenotypes revealed developmental defects of the novel common symbiosis mutants in both symbioses, which demonstrates that common symbiosis mechanisms also contribute to a range of functions at later or different stages of symbiont infection.

  6. 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.

  7. Identification of Arbuscular Mycorrhiza (AM)-Responsive microRNAs in Tomato.

    Science.gov (United States)

    Wu, Ping; Wu, Yue; Liu, Cheng-Chen; Liu, Li-Wei; Ma, Fang-Fang; Wu, Xiao-Yi; Wu, Mian; Hang, Yue-Yu; Chen, Jian-Qun; Shao, Zhu-Qing; Wang, Bin

    2016-01-01

    A majority of land plants can form symbiosis with arbuscular mycorrhizal (AM) fungi. MicroRNAs (miRNAs) have been implicated to regulate this process in legumes, but their involvement in non-legume species is largely unknown. In this study, by performing deep sequencing of sRNA libraries in tomato roots and comparing with tomato genome, a total of 700 potential miRNAs were predicted, among them, 187 are known plant miRNAs that have been previously deposited in miRBase. Unlike the profiles in other plants such as rice and Arabidopsis, a large proportion of predicted tomato miRNAs was 24 nt in length. A similar pattern was observed in the potato genome but not in tobacco, indicating a Solanum genus-specific expansion of 24-nt miRNAs. About 40% identified tomato miRNAs showed significantly altered expressions upon Rhizophagus irregularis inoculation, suggesting the potential roles of these novel miRNAs in AM symbiosis. The differential expression of five known and six novel miRNAs were further validated using qPCR analysis. Interestingly, three up-regulated known tomato miRNAs belong to a known miR171 family, a member of which has been reported in Medicago truncatula to regulate AM symbiosis. Thus, the miR171 family likely regulates AM symbiosis conservatively across different plant lineages. More than 1000 genes targeted by potential AM-responsive miRNAs were provided and their roles in AM symbiosis are worth further exploring.

  8. Lights off for arbuscular mycorrhiza: On its symbiotic functioning under light deprivation

    Directory of Open Access Journals (Sweden)

    Tereza eKonvalinková

    2016-06-01

    Full Text Available Plants are often exposed to shade over different time scales and this may substantially affect not only their own growth, but also development and functioning of the energetically dependent organisms. Among those, the root symbionts such as arbuscular mycorrhizal (AM fungi and rhizobia represent particularly important cases – on the one hand, they consume a significant share of plant carbon (C budget and, on the other, they generate a number of important nutritional feedbacks on their plant hosts, often resulting in a net positive effect on their host growth and/or fitness. Here we discuss our previous results comparing mycorrhizal performance under different intensities and durations of shade (Konvalinková et al., 2015 in a broader context of previously published literature. Additionally, we review publicly available knowledge on the root colonization and mycorrhizal growth responses in AM plants under light deprivation. Experimental evidence shows that sudden and intensive decrease of light availability to a mycorrhizal plant triggers rapid deactivation of phosphorus transfer from the AM fungus to the plant already within a few days, implying active and rapid response of the AM fungus to the energetic status of its plant host. When AM plants are exposed to intensive shading on longer time scales (weeks to months, positive mycorrhizal growth responses (MGR are often decreasing and may eventually become negative. This is most likely due to the high C cost of the symbiosis relative to the C availability, and failure of plants to fully compensate for the fungal C demand under low light. Root colonization by AM fungi often declines under low light intensities, although the active role of plants in regulating the extent of root colonization has not yet been unequivocally demonstrated. Quantitative information on the rates and dynamics of C transfer from the plant to the fungus is mostly missing, as is the knowledge on the involved molecular

  9. Lights Off for Arbuscular Mycorrhiza: On Its Symbiotic Functioning under Light Deprivation.

    Science.gov (United States)

    Konvalinková, Tereza; Jansa, Jan

    2016-01-01

    Plants are often exposed to shade over different time scales and this may substantially affect not only their own growth, but also development and functioning of the energetically dependent organisms. Among those, the root symbionts such as arbuscular mycorrhizal (AM) fungi and rhizobia represent particularly important cases-on the one hand, they consume a significant share of plant carbon (C) budget and, on the other, they generate a number of important nutritional feedbacks on their plant hosts, often resulting in a net positive effect on their host growth and/or fitness. Here we discuss our previous results comparing mycorrhizal performance under different intensities and durations of shade (Konvalinková et al., 2015) in a broader context of previously published literature. Additionally, we review publicly available knowledge on the root colonization and mycorrhizal growth responses in AM plants under light deprivation. Experimental evidence shows that sudden and intensive decrease of light availability to a mycorrhizal plant triggers rapid deactivation of phosphorus transfer from the AM fungus to the plant already within a few days, implying active and rapid response of the AM fungus to the energetic status of its plant host. When AM plants are exposed to intensive shading on longer time scales (weeks to months), positive mycorrhizal growth responses (MGR) are often decreasing and may eventually become negative. This is most likely due to the high C cost of the symbiosis relative to the C availability, and failure of plants to fully compensate for the fungal C demand under low light. Root colonization by AM fungi often declines under low light intensities, although the active role of plants in regulating the extent of root colonization has not yet been unequivocally demonstrated. Quantitative information on the rates and dynamics of C transfer from the plant to the fungus is mostly missing, as is the knowledge on the involved molecular mechanisms. Therefore

  10. Influence of arbuscular mycorrhizae on the root system of maize plants under salt stress.

    Science.gov (United States)

    Sheng, Min; Tang, Ming; Chen, Hui; Yang, Baowei; Zhang, Fengfeng; Huang, Yanhui

    2009-07-01

    Salt stress has become a severe global problem, and salinity is one of the most important abiotic factors limiting plant growth and yield. It is known that arbuscular mycorrhizal (AM) fungi decrease plant yield losses under salinity. With the aim of determining whether AM inoculation would give an advantage to root development under salt stress, a greenhouse experiment was carried out with AM or without AM fungi. Maize plants were grown in a sand and soil mixture with 5 NaCl levels (0, 0.5, 1.0, 1.5, and 2.0 g/kg dry substrate) for 55 days, following 15 days of nonsaline pretreatment. At all salt levels, mycorrhizal plants had higher dry shoot and root mass, higher root activity, and lower root to shoot ratios than non-mycorrhizal plants. In salt-free soil, root length, root surface area, root volume, and number of root tips and forks were significantly larger in mycorrhizal plants than in non-mycorrhizal plants, whereas, under salt stress, average root diameter and root volume of mycorrhizal plants were larger than those of non-mycorrhizal plants. Regardless of the NaCl level, mycorrhizal plants had lower specific root length, lower percentage of root length in the 0-0.2 mm diameter class, and higher percentage of root length in both the 0.2-0.4 mm and 0.4-0.6 mm diameter classes, which suggests that the root system shows a significant shift towards a thicker root system when maize plants were inoculated with Glomus mosseae (Nicolson & Gerdemann). The results presented here indicate that the improvements in root activity and the coarse root system of mycorrhizal maize may help in alleviating salt stress on the plant.

  11. Effects of arbuscular mycorrhiza inoculation on growth and yield of tomato (Lycopersicum esculentum Mill. under salinity stress

    Directory of Open Access Journals (Sweden)

    D.R.R. Damaiyanti

    2015-10-01

    Full Text Available Objective of the research was to study the effect mycorrhiza on growth and yield of tomato. The experiment was conducted in screen house 14 m x 10.5 m, in Pasuruan on November 2013 until March 2014, The experiment was conducted as a factorial randomized complete design. The first factor was dose of mycorrhiza (without mycorrhiza, 5 g mycorrhiza, 10 g mycorrhiza, and 20 g mycorrhiza. The second factor was the salinity stress level (without NaCl, 2500 ppm NaCl, 5000 ppm NaCl, and 7500 ppm NaCl. The results showed that salinity stress at the level 7500 ppm decreased the amount of fruit by 30.84% and fresh weight per hectare decreased by 51.72%. Mycorrhizal application was not able to increase the growth and yield in saline stress conditions; it was shown by the level of infection and the number of spores on the roots of tomato plants lower the salinity level 5000 ppm and 7500 ppm. But separately, application of 20 g mycorrhiza enhanced plant growth, such as plant height, leaf area, leaf number and proline. Application of 20 g mycorrhiza increased the yield by 35.99%.

  12. IMPACT OF BRACHIARIA, ARBUSCULAR MYCORRHIZA, AND POTASSIUM ENRICHED RICE STRAW COMPOST ON ALUMINIUM, POTASSIUM AND STABILITY OF ACID SOIL AGGREGATES

    Directory of Open Access Journals (Sweden)

    Bariot Hafif

    2013-04-01

    Full Text Available Acid soil is commonly grown with cassava, which in general, tolerate low soil  fertility and aluminum (Al toxicity. However, without any improvement efforts such soil will become worse. Intercropping cassava with Brachiaria decumbens (BD which adapts to acid soil and tolerates low fertility soils as well as application of arbuscular mycorrhiza (AM and organic matters are among the important efforts to rehabilitate this soil. The experiment was conducted to  examine the impact of BD, AM, and potassium (K enriched rice straw compost on exchangeable Al, available K, and stability of soil aggregates. Experiment was arranged in a completely randomized design with three factors and three replications. The first factor was BD as cassava intercropping, the second factor was AM, and the third factor was 2 t ha-1 rice straw compost enriched with 0 kg, 50 kg, 100 kg, and 200 kg KCl ha-1. Brick pots (1 m length x 1 m width x 0.45 m depth filled with Kanhapludult soil was used for growing cassava in which row of BD was planted at 60 cm from cassava stem. K-enriched rice straw compost and AM (10 g per stem were applied around cassava stem at 2 and 12 days after planting, respectively. BD was cut every 30 days and the cutting was returned to the soil. Soil exchangeable Al was analyzed at 0, 3, 6 and 9 months after planting (MAP, while Al and K contents as well as aggregate stability were measured at 6 MAP. The results showed that planting BD decreased 33% exchangeable Al, which means that the root exudates of this grass was effective in detoxifying Al3+. Treatment of BD and/or in combination with AM was effective in preserving K added to the soil, increasing total polysaccharides, and improving soil aggregate stability. This indicated that planting BD and applying AM and Kenriched rice straw compost improved acid soil fertility, and therefore can be recommended in cassava cultivation.

  13. Resolving the 'nitrogen paradox' of arbuscular mycorrhizas: fertilization with organic matter brings considerable benefits for plant nutrition and growth.

    Science.gov (United States)

    Thirkell, Tom J; Cameron, Duncan D; Hodge, Angela

    2016-08-01

    Arbuscular mycorrhizal fungi (AMF) can transfer nitrogen (N) to host plants, but the ecological relevance is debated, as total plant N and biomass do not generally increase. The extent to which the symbiosis is mutually beneficial is thought to rely on the stoichiometry of N, phosphorus (P) and carbon (C) availability. While inorganic N fertilization has been shown to elicit strong mutualism, characterized by improved plant and fungal growth and mineral nutrition, similar responses following organic N addition are lacking. Using a compartmented microcosm experiment, we determined the significance to a mycorrhizal plant of placing a (15) N-labelled, nitrogen-rich patch of organic matter in a compartment to which only AMF hyphae had access. Control microcosms denied AMF hyphal access to the patch compartment. When permitted access to the patch compartment, the fungus proliferated extensively in the patch and transferred substantial quantities of N to the plant. Moreover, our data demonstrate that allowing hyphal access to an organic matter patch enhanced total plant N and P contents, with a simultaneous and substantial increase in plant biomass. Furthermore, we demonstrate that organic matter fertilization of arbuscular mycorrhizal plants can foster a mutually beneficial symbiosis based on nitrogen transfer, a phenomenon previously thought irrelevant.

  14. Subcellular nutrient element localization and enrichment in ecto- and arbuscular mycorrhizas of field-grown beech and ash trees indicate functional differences.

    Directory of Open Access Journals (Sweden)

    Jasmin Seven

    Full Text Available Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior are colonized by arbuscular mycorrhizal fungi (AM and beech roots (Fagus sylvatica by ectomycorrhizal fungi (EcM. Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations

  15. Subcellular nutrient element localization and enrichment in ecto- and arbuscular mycorrhizas of field-grown beech and ash trees indicate functional differences.

    Science.gov (United States)

    Seven, Jasmin; Polle, Andrea

    2014-01-01

    Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of

  16. Influence of arbuscular mycorrhizae on biomass and root morphology of selected strawberry cultivars under salt stress

    National Research Council Canada - National Science Library

    Fan, Li; Dalpe, Yolande; Fang, Chengquan; Dube, Claudine; Khanizadeh, Shahrokh

    2011-01-01

    ...) and were inoculated and noninoculated (control) with AMF Glomus irregulare . The presence of AMF significantly changed root morphology and increased root-length percentages of medium (0.5 mm 1.5 mm...

  17. Fungos micorrízicos-arbusculares no desenvolvimento de mudas de helicônia e gérbera micropropagadas Application of arbuscular mycorrhiza to micropropagated heliconia and gerbera plants during acclimatization period

    Directory of Open Access Journals (Sweden)

    Aurora Yoshiko Sato

    1999-03-01

    Full Text Available Plântulas micropropagadas de helicônia (Heliconia sp gérbera (Gerbera sp de vaso, foram aclimatadas em substrato (torta de filtro 50%, solo 30% e areia 20%, inoculado com três espécies de fungo micorrízico (Glomus clarum Nicolson. & Schenck, Glomus etunicatum Becker & Gerdemann e Gigaspora margarita Becker & Hall e uma mistura destas espécies (inóculo múltiplo. As avaliações quanto ao desenvolvimento da parte aérea e do sistema radicular e porcentagem de colonização, foram feitas aos 60 dias para gérbera e aos 90 dias para helicônia, após transplante. As duas espécies comportaram-se de modo diferente em resposta à micorrização. Glomus etunicatum não colonizou bem nenhuma das duas espécies estudadas. Apesar da elevada colonização, a helicônia não se beneficiou da inoculação, enquanto que a gérbera beneficiou-se da inoculação com G. clarum, G. etunicatum e do inóculo misto.Heliconia (Heliconia sp. and pot gerbera plantlets (Gerbera sp. obtained by in vitro micropropagation on Murashige and Skoog (MS medium were inoculated with 3 vesicular arbuscular mycorrhiza (VAM species and a mixture of three species. A control treatment without inoculation was also included. The plantlets were acclimated in a mixture of soil 30%, sand 20% and "torta de filtro" 50%. The fungal species were Glomus clarum, Glomus etunicatum and Gigaspora margarita. At 60 days for gerbera and 90 days for heliconia after the inoculation, fresh and dry matter of the aerial and root parts were determined, and the percentage of mycorrhizal colonization of the roots was obtained. Both species behaved different to mycorrhization. Glomus etunicatum did not show to be effective in colonization of heliconia and gerbera. Colonization was high, but heliconia did not benefit from this inoculation, however Gerbera was benefited by G. clarum, G. etunicatum and mixture inoculation.

  18. Arbuscular mycorrhiza and water and nutrient supply differently impact seedling performance of dry woodland species with different acquisition strategies

    NARCIS (Netherlands)

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

    2015-01-01

    Background: Arbuscular mycorrhizal (AM) fungi increase seedling survival and performance through enhancement of nutrient and water uptake under stress conditions. Acacia etbaica, A. senegal and Boswellia papyrifera dominate large areas in African drylands where both moisture and nutrients are

  19. Arbuscular mycorrhiza and water and nutrient supply differently impact seedling performance of dry woodland species with different acquisition strategies

    NARCIS (Netherlands)

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

    2015-01-01

    Background: Arbuscular mycorrhizal (AM) fungi increase seedling survival and performance through enhancement of nutrient and water uptake under stress conditions. Acacia etbaica, A. senegal and Boswellia papyrifera dominate large areas in African drylands where both moisture and nutrients are limite

  20. Micorrizas arbusculares y endófitos septados oscuros en Gentianaceae nativas de la Argentina Arbuscular mycorrhizas and dark septates endophytes in native Gentianaceae from Argentina

    OpenAIRE

    Leonardo A. Salvarredi; Esteban M Crespo; Eugencia Menoyo; Eva M. Filippa; Barboza, Gloria E.; Mónica A Lugo

    2010-01-01

    Se estudió la colonización de raíces por simbiontes fúngicos en cinco especies de Gentianaceae nativas distribuidas en distintos ambientes de la Argentina, cuatro pertenecientes a Gentianella y una a Gentiana. Se observaron estructuras micorrícicas arbusculares pertenecientes al tipo Paris (hifas y circunvoluciones intracelulares) y endófitos septados oscuros (SO) (hifas y microesclerocios). Tres de las especies estudiadas se asociaron a micorrizas arbusculares (MA) y SO, una sólo a SO y otra...

  1. Influence of arbuscular mycorrhizae on biomass production and nitrogen fixation of berseem clover plants subjected to water stress.

    Science.gov (United States)

    Saia, Sergio; Amato, Gaetano; Frenda, Alfonso Salvatore; Giambalvo, Dario; Ruisi, Paolo

    2014-01-01

    Several studies, performed mainly in pots, have shown that arbuscular mycorrhizal symbiosis can mitigate the negative effects of water stress on plant growth. No information is available about the effects of arbuscular mycorrhizal symbiosis on berseem clover growth and nitrogen (N) fixation under conditions of water shortage. A field experiment was conducted in a hilly area of inner Sicily, Italy, to determine whether symbiosis with AM fungi can mitigate the detrimental effects of drought stress (which in the Mediterranean often occurs during the late period of the growing season) on forage yield and symbiotic N2 fixation of berseem clover. Soil was either left under water stress (i.e., rain-fed conditions) or the crop was well-watered. Mycorrhization treatments consisted of inoculation of berseem clover seeds with arbuscular mycorrhizal spores or suppression of arbuscular mycorrhizal symbiosis by means of fungicide treatments. Nitrogen biological fixation was assessed using the 15N-isotope dilution technique. Arbuscular mycorrhizal symbiosis was able to mitigate the negative effect of water stress on berseem clover grown in a typical semiarid Mediterranean environment. In fact, under water stress conditions, arbuscular mycorrhizal symbiosis resulted in increases in total biomass, N content, and N fixation, whereas no effect of crop mycorrhization was observed in the well-watered treatment.

  2. Influence of arbuscular mycorrhizae on biomass production and nitrogen fixation of berseem clover plants subjected to water stress.

    Directory of Open Access Journals (Sweden)

    Sergio Saia

    Full Text Available Several studies, performed mainly in pots, have shown that arbuscular mycorrhizal symbiosis can mitigate the negative effects of water stress on plant growth. No information is available about the effects of arbuscular mycorrhizal symbiosis on berseem clover growth and nitrogen (N fixation under conditions of water shortage. A field experiment was conducted in a hilly area of inner Sicily, Italy, to determine whether symbiosis with AM fungi can mitigate the detrimental effects of drought stress (which in the Mediterranean often occurs during the late period of the growing season on forage yield and symbiotic N2 fixation of berseem clover. Soil was either left under water stress (i.e., rain-fed conditions or the crop was well-watered. Mycorrhization treatments consisted of inoculation of berseem clover seeds with arbuscular mycorrhizal spores or suppression of arbuscular mycorrhizal symbiosis by means of fungicide treatments. Nitrogen biological fixation was assessed using the 15N-isotope dilution technique. Arbuscular mycorrhizal symbiosis was able to mitigate the negative effect of water stress on berseem clover grown in a typical semiarid Mediterranean environment. In fact, under water stress conditions, arbuscular mycorrhizal symbiosis resulted in increases in total biomass, N content, and N fixation, whereas no effect of crop mycorrhization was observed in the well-watered treatment.

  3. Plants without arbuscular mycorrhizae

    Science.gov (United States)

    P is second to N as the most limiting element for plant growth. Plants have evolved a number of effective strategies to acquire P and grow in a P-limited environment. Physiological, biochemical, and molecular studies of P-deficiency adaptations that occur in non-mycorrhizal species have provided str...

  4. A tandem Kunitz protease inhibitor (KPI106)-serine carboxypeptidase (SCP1) controls mycorrhiza establishment and arbuscule development in Medicago truncatula.

    Science.gov (United States)

    Rech, Stefanie S; Heidt, Sven; Requena, Natalia

    2013-09-01

    Plant proteases and protease inhibitors are involved in plant developmental processes including those involving interactions with microbes. Here we show that a tandem between a Kunitz protease inhibitor (KPI106) and a serine carboxypeptidase (SCP1) controls arbuscular mycorrhiza development in the root cortex of Medicago truncatula. Both proteins are only induced during mycorrhiza formation and belong to large families whose members are also mycorrhiza-specific. Furthermore, the interaction between KPI106 and SCP1 analysed using the yeast two-hybrid system is specific, indicating that each family member might have a defined counterpart. In silico docking analysis predicted a putative P1 residue in KPI106 (Lys173) that fits into the catalytic pocket of SCP1, suggesting that KPI106 might inhibit the enzyme activity by mimicking the protease substrate. In vitro mutagenesis of the Lys173 showed that this residue is important in determining the strength and specificity of the interaction. The RNA interference (RNAi) inactivation of the serine carboxypeptidase SCP1 produces aberrant mycorrhizal development with an increased number of septated hyphae and degenerate arbuscules, a phenotype also observed when overexpressing KPI106. Protease and inhibitor are both secreted as observed when expressed in Nicotiana benthamiana epidermal cells. Taken together we envisage a model in which the protease SCP1 is secreted in the apoplast where it produces a peptide signal critical for proper fungal development within the root. KPI106 also at the apoplast would modulate the spatial and/or temporal activity of SCP1 by competing with the protease substrate.

  5. Arbuscular mycorrhizae improve low temperature tolerance in cucumber via alterations in H2O2 accumulation and ATPase activity.

    Science.gov (United States)

    Liu, Airong; Chen, Shuangchen; Chang, Rui; Liu, Dilin; Chen, Haoran; Ahammed, Golam Jalal; Lin, Xiaomin; He, Chaoxing

    2014-11-01

    The combined effects of arbuscular mycorrhizal fungi (AMF) and low temperature (LT) on cucumber plants were investigated with respect to biomass production, H2O2 accumulation, NADPH oxidase, ATPase activity and related gene expression. Mycorrhizal colonization ratio was gradually increased after AMF-inoculation. However, LT significantly decreased mycorrhizal colonization ability and mycorrhizal dependency. Regardless of temperature, the total fresh and dry mass, and root activity of AMF-inoculated plants were significantly higher than that of the non-AMF control. The H2O2 accumulation in AMF-inoculated roots was decreased by 42.44% compared with the control under LT. H2O2 predominantly accumulated on the cell walls of apoplast but was hardly detectable in the cytosol or organelles of roots. Again, NADPH oxidase activity involved in H2O2 production was significantly reduced by AMF inoculation under LT. AMF-inoculation remarkably increased the activities of P-type H(+)-ATPase, P-Ca(2+)-ATPase, V-type H(+)-ATPase, total ATPase activity, ATP concentration and plasma membrane protein content in the roots under LT. Additionally, ATP concentration and expression of plasma membrane ATPase genes were increased by AMF-inoculation. These results indicate that NADPH oxidase and ATPase might play an important role in AMF-mediated tolerance to chilling stress, thereby maintaining a lower H2O2 accumulation in the roots of cucumber.

  6. Evaluation of Two Biochemical Markers for Salt Stress in Three Pistachio Rootstocks Inoculated with Arbuscular Mycorrhiza (Glomus mosseae

    Directory of Open Access Journals (Sweden)

    Shamshiri M.H.

    2014-03-01

    Full Text Available The possible involvement of the methylglyoxal and proline accumulation in leaves and roots of three pistachio rootstocks, cv. Sarakha, Abareqi and Bane baghi, pre-inoculated with arbuscular mycorrhizal fungus (Glomus mosseae in response to salt stress was studied during a greenhouse experiment in 2013. Six months old pistachio seedlings were exposed to four salinity levels of irrigation water (EC of 0.5 as control, 5, 10 and 15 dS m-1 for 70 days. Methylglyoxal and proline of the roots and leaves were increased by increasing salt stress. The highest concentrations of proline in leaves and roots were recorded in Abareqi rootstock while the lowest concentration was observed in Sarakhs. In general, a negative relationship was obtained between proline and methylglyoxal concentrations in both tissues especially at two highest levels of salinity. A very strong relationship between salinity and measured biochemical markers were found. The level of both biomarkers were reduced in both tissues and in all rootstocks as the effect of mycorrhizal symbiosis. Root colonization percentage was declined as the effect of salinity in Abareqi and Bane baghi and not in Sarakhs.

  7. Arbuscular mycorrhiza improve growth, nitrogen uptake, and nitrogen use efficiency in wheat grown under elevated CO2.

    Science.gov (United States)

    Zhu, Xiancan; Song, Fengbin; Liu, Shengqun; Liu, Fulai

    2016-02-01

    Effects of the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis on plant growth, carbon (C) and nitrogen (N) accumulation, and partitioning was investigated in Triticum aestivum L. plants grown under elevated CO2 in a pot experiment. Wheat plants inoculated or not inoculated with the AM fungus were grown in two glasshouse cells with different CO2 concentrations (400 and 700 ppm) for 10 weeks. A (15)N isotope labeling technique was used to trace plant N uptake. Results showed that elevated CO2 increased AM fungal colonization. Under CO2 elevation, AM plants had higher C concentration and higher plant biomass than the non-AM plants. CO2 elevation did not affect C and N partitioning in plant organs, while AM symbiosis increased C and N allocation into the roots. In addition, plant C and N accumulation, (15)N recovery rate, and N use efficiency (NUE) were significantly higher in AM plants than in non-AM controls under CO2 enrichment. It is concluded that AM symbiosis favors C and N partitioning in roots, increases C accumulation and N uptake, and leads to greater NUE in wheat plants grown at elevated CO2.

  8. Regulation by arbuscular mycorrhizae of the integrated physiological response to salinity in plants: new challenges in physiological and molecular studies.

    Science.gov (United States)

    Ruiz-Lozano, Juan Manuel; Porcel, Rosa; Azcón, Charo; Aroca, Ricardo

    2012-06-01

    Excessive salt accumulation in soils is a major ecological and agronomical problem, in particular in arid and semi-arid areas. Excessive soil salinity affects the establishment, development, and growth of plants, resulting in important losses in productivity. Plants have evolved biochemical and molecular mechanisms that may act in a concerted manner and constitute the integrated physiological response to soil salinity. These include the synthesis and accumulation of compatible solutes to avoid cell dehydration and maintain root water uptake, the regulation of ion homeostasis to control ion uptake by roots, compartmentation and transport into shoots, the fine regulation of water uptake and distribution to plant tissues by the action of aquaporins, the reduction of oxidative damage through improved antioxidant capacity and the maintenance of photosynthesis at values adequate for plant growth. Arbuscular mycorrhizal (AM) symbiosis can help the host plants to cope with the detrimental effects of high soil salinity. There is evidence that AM symbiosis affects and regulates several of the above mentioned mechanisms, but the molecular bases of such effects are almost completely unknown. This review summarizes current knowledge about the effects of AM symbiosis on these physiological mechanisms, emphasizing new perspectives and challenges in physiological and molecular studies on salt-stress alleviation by AM symbiosis.

  9. Impact on Arbuscular Mycorrhiza Formation of Pseudomonas Strains Used as Inoculants for Biocontrol of Soil-Borne Fungal Plant Pathogens

    Science.gov (United States)

    Barea, J. M.; Andrade, G.; Bianciotto, V.; Dowling, D.; Lohrke, S.; Bonfante, P.; O’Gara, F.; Azcon-Aguilar, C.

    1998-01-01

    The arbuscular mycorrhizal symbiosis, a key component of agroecosystems, was assayed as a rhizosphere biosensor for evaluation of the impact of certain antifungal Pseudomonas inoculants used to control soil-borne plant pathogens. The following three Pseudomonas strains were tested: wild-type strain F113, which produces the antifungal compound 2,4-diacetylphloroglucinol (DAPG); strain F113G22, a DAPG-negative mutant of F113; and strain F113(pCU203), a DAPG overproducer. Wild-type strain F113 and mutant strain F113G22 stimulated both mycelial development from Glomus mosseae spores germinating in soil and tomato root colonization. Strain F113(pCU203) did not adversely affect G. mosseae performance. Mycelial development, but not spore germination, is sensitive to 10 μM DAPG, a concentration that might be present in the rhizosphere. The results of scanning electron and confocal microscopy demonstrated that strain F113 and its derivatives adhered to G. mosseae spores independent of the ability to produce DAPG. PMID:9603857

  10. Effect of Arbuscular Mycorrhiza Fungi (AMF and The Organic Material to The Glomalin Production and The Soil Physical Properties of Ultisols

    Directory of Open Access Journals (Sweden)

    Amrizal Saidi

    2015-01-01

    Full Text Available Metabolism of Arbuscular mycorrhiza fungi (AMF requires nitrogen from organic matter to produce glomalin on hyphae. Glomalin able to granulate the soil particles are dispersed to form a stable soil aggregates to create good soil structure. Improvement of soil structure will provide optimal conditions for the development of organisms and plant roots. AMF and the use of organic matter as a source of N for the AMF has done research on Sitiung Ultisol. The purpose of this study was to determine the effect of AMF and organic material to the glomalin production, as well as its relationship with the soil physical properties. This research was conducted at the greenhouse of Faculty Agriculture Andalas University Padang. West Sumatra Indonesia. Soil samples of soil physical properties observed in the area of mycorrhiza hyphae found (mycorhizalsphere which is influenced by differences glomalin generated by the AMF. The results of the reserach showed that treatment of AMF and Nitrogen organic ingredients affect significantly on the glomalin, whereas the effect of treatment it gives a different effect on soil physical properties. Organic materials do not affect significantly on the availability of soil water content, but very significant effect on water content at 2.54 pF. AMF species that produce a higher glomalin can be significant in improving soil physical properties, ie versiforme G. and G. luteum although without the use of organic materials or organic. Both these species give a positive response to the growth of maize by mycorrhizalsphere (MGR = mycorrhizal growth response and nutrient uptake of maize.

  11. Mycorrhiza and crop production

    Energy Technology Data Exchange (ETDEWEB)

    Hayman, D.S.

    1980-10-09

    This article describes recent research with vesicular-arbuscular mycorrhiza, a symbiotic fungus-root association. The suggestion that the symbiotic association may be harnessed to achieve more economical use of phosphate fertilizers is discussed and the results from various test crops are given.

  12. Analyzing the soybean transcriptome during autoregulation of mycorrhization identifies the transcription factors GmNF-YA1a/b as positive regulators of arbuscular mycorrhization.

    Science.gov (United States)

    Schaarschmidt, Sara; Gresshoff, Peter M; Hause, Bettina

    2013-06-18

    Similarly to the legume-rhizobia symbiosis, the arbuscular mycorrhiza interaction is controlled by autoregulation representing a feedback inhibition involving the CLAVATA1-like receptor kinase NARK in shoots. However, little is known about signals and targets down-stream of NARK. To find NARK-related transcriptional changes in mycorrhizal soybean (Glycine max) plants, we analyzed wild-type and two nark mutant lines interacting with the arbuscular mycorrhiza fungus Rhizophagus irregularis. Affymetrix GeneChip analysis of non-inoculated and partially inoculated plants in a split-root system identified genes with potential regulation by arbuscular mycorrhiza or NARK. Most transcriptional changes occur locally during arbuscular mycorrhiza symbiosis and independently of NARK. RT-qPCR analysis verified nine genes as NARK-dependently regulated. Most of them have lower expression in roots or shoots of wild type compared to nark mutants, including genes encoding the receptor kinase GmSIK1, proteins with putative function as ornithine acetyl transferase, and a DEAD box RNA helicase. A predicted annexin named GmAnnx1a is differentially regulated by NARK and arbuscular mycorrhiza in distinct plant organs. Two putative CCAAT-binding transcription factor genes named GmNF-YA1a and GmNF-YA1b are down-regulated NARK-dependently in non-infected roots of mycorrhizal wild-type plants and functional gene analysis confirmed a positive role for these genes in the development of an arbuscular mycorrhiza symbiosis. Our results indicate GmNF-YA1a/b as positive regulators in arbuscular mycorrhiza establishment, whose expression is down-regulated by NARK in the autoregulated root tissue thereby diminishing subsequent infections. Genes regulated independently of arbuscular mycorrhization by NARK support an additional function of NARK in symbioses-independent mechanisms.

  13. A survey of the arbuscular mycorrhiza occurrence in paepalanthus bromelioides and Bulbostylis sp. in rupestrian fields, Brazil

    OpenAIRE

    PAGANO, M.C.; SCOTTI, M. R.

    2009-01-01

    Este estudio registra el porcentaje de colonización micorrízica, así como la densidad de esporas, de hongos micorrízico arbusculares de Paepalanthus bromelioides (Eriocaulaceae) y Bulbostylis sp. (Cyperaceae) en el sureste de Brasil. El muestreo del suelo y raíces de estas especies se realizó en 2006. Se identificaron las esporas de hongos micorrízico arbusculares y se evaluó la colonización en las raíces. Las dos especies vegetales mostraron micotrofía. Los tres géneros de hongos micorrízico...

  14. The Effects of Arbuscular Mycorrhiza Fungi on Dry Matter and Concentrations of Nitrogen, Phosphorus and Potassium in Berseem Clover, by Cadmium stress

    Directory of Open Access Journals (Sweden)

    hashem aram

    2016-02-01

    Full Text Available Introduction: Soil contaminations with heavy metals represent a potential risk to the biosphere and leads to increased concentration in ground and surface water. Therefore metals mobility in soil has been extensively studied in the last decades. Use of agrochemicals such as synthetic fertilizers and pesticides has resulted in soil and water pollution, and loss of biodiversity. Cadmium is a heavy metal with a strong effect on crop quality. Moreover, it is a very mobile element in the environment. Plants can easily uptake cadmium and transfer it to other organs. Experiments on the effects of cadmium on the contents of macro elements in plants are scarce and therefore the mechanism of its effect has not yet been fully explained. Contaminated soil can be remediated by chemical, physical or biological techniques. Mycorrhiza is the mutualistic symbiosis (non-pathogenic association between soil-borne fungi with the roots of higher plants. Arbuscular mycorrhizal fungi (AMF are obligate biotrophs, which can form mutualistic symbioses with the roots of around 80% of plant species. Arbuscular mycorrhiza have been observed to play a vital role in metal tolerance and accumulation. Many workers have reported enhancement of phosphate uptake and growth of leguminous plants by vesicular arbuscular mycorhizal fungi (AMF. Materials and Methods: One study performed the factorial experiment based on completely randomized design (CRD with three replications in the greenhouse of Agriculture Faculty of Zanjan University. The examined factors include different levels of arbuscular mycorrhizal fungi inoculation (Glomus mosseae (with and without inoculation, and different levels of soil contamination by cadmium (0, 5, 10, 20, 40 and 80 ppm. In this study, arbuscular mycorrhizal fungi Glomus mosseae species were used. These fungi were prepared by the Plant Protection Clinic in Iran – Hamedan. The soil was prepared of arable land of depth of 0-20 cm at the University of

  15. Late activation of the 9-oxylipin pathway during arbuscular mycorrhiza formation in tomato and its regulation by jasmonate signalling

    Science.gov (United States)

    León-Morcillo, Rafael Jorge; Ángel, José; Martín-Rodríguez; Vierheilig, Horst; Ocampo, Juan Antonio; García-Garrido, José Manuel

    2012-01-01

    The establishment of an arbuscular mycorrhizal (AM) symbiotic interaction is a successful strategy for the promotion of substantial plant growth, development, and fitness. Numerous studies have supported the hypothesis that plant hormones play an important role in the establishment of functional AM symbiosis. Particular attention has been devoted to jasmonic acid (JA) and its derivates, which are believed to play a major role in AM symbiosis. Jasmonates belong to a diverse class of lipid metabolites known as oxylipins that include other biologically active molecules. Recent transcriptional analyses revealed up-regulation of the oxylipin pathway during AM symbiosis in mycorrhizal tomato roots and indicate a key regulatory role for oxylipins during AM symbiosis in tomato, particularly those derived from the action of 9-lipoxygenases (9-LOXs). Continuing with the tomato as a model, the spatial and temporal expression pattern of genes involved in the 9-LOX pathway during the different stages of AM formation in tomato was analysed. The effects of JA signalling pathway changes on AM fungal colonization were assessed and correlated with the modifications in the transcriptional profiles of 9-LOX genes. The up-regulation of the 9-LOX oxylipin pathway in mycorrhizal wild-type roots seems to depend on a particular degree of AM fungal colonization and is restricted to the colonized part of the roots, suggesting that these genes could play a role in controlling fungal spread in roots. In addition, the results suggest that this strategy of the plant to control AM fungi development within the roots is at least partly dependent on JA pathway activation. PMID:22442425

  16. Mutualistic functioning of indigenous arbuscular mycorrhizae in spring barley and winter wheat after cessation of long-term phosphate fertilization

    NARCIS (Netherlands)

    Dekkers, T.B.M.; Werff, van der P.A.

    2001-01-01

    The influence of 23 years of phosphorus (P) application at three annual rates of 0, 17.5 and 52.5 kg ha-1 on arbuscular mycorrhizal (AM) fungal colonization was studied 10 years after the fertilization treatment ended. The annual application of 52.5 kg ha-1 was about twice the annual crop P

  17. Plant growth responses to elevated atmospheric CO2 are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

    DEFF Research Database (Denmark)

    Jakobsen, Iver; Smith, Sally E.; Smith, F. Andrew

    2016-01-01

    Capturing the full growth potential in crops under future elevated CO2 (eCO2) concentrations would be facilitated by improved understanding of eCO2 effects on uptake and use of mineral nutrients. This study investigates interactions of eCO2, soil phosphorus (P), and arbuscular mycorrhizal (AM...

  18. Arbuscular mycorrhiza improve growth, nitrogen uptake, and nitrogen use efficiency in wheat grown under elevated CO2

    DEFF Research Database (Denmark)

    Zhu, Xiancan; Song, Fengbin; Liu, Shengqun

    2016-01-01

    Effects of the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis on plant growth, carbon (C) and nitrogen (N) accumulation, and partitioning was investigated in Triticum aestivum L. plants grown under elevated CO2 in a pot experiment. Wheat plants inoculated or not inoculated with the AM...

  19. No significant transfer of N and P from Pueraria Phaseoloides to Hevea Brasiliensis via Hyphal links of Arbuscular Mycorrhiza

    DEFF Research Database (Denmark)

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

    1994-01-01

    The possible role of arbuscular mycorrhizal fungi in the transfer of nitrogen and phosphorus from Pueraria phaseoloides (donor) to Hevea brasiliensis (receiver) was examined. P. phaseoloides is used as a cover crop in rubber tree (H. brasiliensis) plantations. Roots of donor and receiver plants...

  20. Changes of antioxidative enzymes and cell membrane osmosis in tomato colonized by arbuscular Mycorrhizae under NaCl stress.

    Science.gov (United States)

    He, Zhongqun; He, Chaoxing; Zhang, Zhibin; Zou, Zhirong; Wang, Huaisong

    2007-10-01

    Salinity toxicity is a worldwide agricultural and eco-environmental problem. Many literatures show that arbuscular mycorrhizal fungi (AMF) can enhance salt tolerance of many plants and some physiological changes occurred in AM symbiosis under salt stress. However, the role of ROS-scavenging enzymes in AM tomato is still unknown in continuous salt stress. This study investigated the effect of Glomus mosseae on tomato growth, cell membrane osmosis and examined the antioxidants (superoxide-dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; peroxidase, POD) responses in roots of mycorrhizal tomato and control under different NaCl stress for 40 days in potted culture. NaCl solution (0, 0.5 and 1%) was added to organic soil in the irrigation water after 45 days inoculated by AMF (Glomus mosseae). (1) AMF inoculation improved tomato growth under salt or saltless condition and reduced cell membrane osmosis, MDA (malonaldehyde) content in salinity. So the salt tolerance of tomato was enhanced by AMF; (2) SOD, APX and POD activity in roots of AM symbiosis were significantly higher than corresponding non-AM plants in salinity or saltless condition. However, CAT activity was transiently induced by AMF and then suppressed to a level similar with non-AM seedlings; (3) higher salinity (1% level) and long stress time suppressed the effect of AMF on SOD, APX, POD and CAT activity; (4) this research suggested that the enhanced salt tolerance in AM symbiosis was mainly related with the elevated SOD, POD and APX activity by AMF which degraded more reactive oxygen species and so alleviated the cell membrane damages under salt stress. Whereas, the elevated SOD, POD and APX activity due to AMF depended on salinity environment.

  1. Structural characterization and molecular identification of arbuscular mycorrhiza morphotypes of Alzatea verticillata (Alzateaceae), a prominent tree in the tropical mountain rain forest of South Ecuador.

    Science.gov (United States)

    Beck, Adela; Haug, Ingeborg; Oberwinkler, Franz; Kottke, Ingrid

    2007-10-01

    The vast majority of the highly diverse trees in the tropical mountain rain forest of South Ecuador form arbuscular mycorrhizas, and previous molecular investigations revealed a high diversity of fungi. In this study, we present a first trial to link fungal DNA-sequences with defined morphotypes characterized on the basis of partly new mycelial features obtained from field material of one tree species, Alzatea verticillata. Fine roots were halved lengthwise to study the mycelium anatomy on one half and to obtain fungal nuclear rDNA coding for the small subunit rRNA of Glomeromycota from the other half. Light microscopy revealed conspicuously large amounts of mycelium attaching to the surface of the rootlets. The mycelium formed fine- or large-branched appressoria-like plates, vesicles of regular or irregular shape, and very fine, multibranched structures ensheathed by septate hyphae. These previously undescribed features of the supraradical mycelia combined with intraradical mycelium structures were used for distinguishing of four main morphogroups and subordinate 14 morphotypes. DNA sequences of Glomus group A, Acaulospora and Gigaspora, were obtained and linked to three morphogroups. Two sequence types within Glomus group A could be tentatively associated to subordinate morphotypes.

  2. Influence of different mineral nitrogen sources (NO3(-)-N vs. NH4(+)-N) on arbuscular mycorrhiza development and N transfer in a Glomus intraradices-cowpea symbiosis.

    Science.gov (United States)

    Ngwene, Benard; Gabriel, Elke; George, Eckhard

    2013-02-01

    Labeled nitrogen ((15)N) was applied to a soil-based substrate in order to study the uptake of N by Glomus intraradices extraradical mycelium (ERM) from different mineral N (NO(3)(-) vs. NH(4)(+)) sources and the subsequent transfer to cowpea plants. Fungal compartments (FCs) were placed within the plant growth substrate to simulate soil patches containing root-inaccessible, but mycorrhiza-accessible, N. The fungus was able to take up both N-forms, NO(3)(-) and NH(4)(+). However, the amount of N transferred from the FC to the plant was higher when NO(3)(-) was applied to the FC. In contrast, analysis of ERM harvested from the FC showed a higher (15)N enrichment when the FC was supplied with (15)NH(4)(+) compared with (15)NO(3)(-). The (15)N shoot/root ratio of plants supplied with (15)NO(3)(-) was much higher than that of plants supplied with (15)NH(4)(+), indicative of a faster transfer of (15)NO(3)(-) from the root to the shoot and a higher accumulation of (15)NH (4)(+) in the root and/or intraradical mycelium. It is concluded that hyphae of the arbuscular mycorrhizal fungus may absorb NH(4)(+) preferentially over NO(3)(-) but that export of N from the hyphae to the root and shoot may be greater following NO(3)(-) uptake. The need for NH(4)(+) to be assimilated into organically bound N prior to transport into the plant is discussed.

  3. 甜菜根际土壤AM真菌分离与分子鉴定%Molecular Detection of Arbuscular Mycorrhiza Fungi in Rhizospheric Soil of Sugarbeet

    Institute of Scientific and Technical Information of China (English)

    接伟光; 蔡柏岩; 白莉

    2010-01-01

    为了揭示丛枝茵根(arbuscular mycorrhiza,AM)真菌与甜菜的共生关系,收集甜菜根系及根际土壤,采用湿筛倾析-蔗糖离心法分离甜菜根围土壤AM真菌孢子.利用形态学和分子生物学方法对分离得到的AM真茵孢子进行分类鉴定,并应用Nested-PCR技术检测甜菜根际土壤AM真茵侵染甜菜根系情况.依据AM真茵孢子形态特征及25S rDNA D1/D2区域序列分析,鉴定出甜菜根围土壤中具有摩西球囊霉(Glomus mosseae),并且应用Nested-PCR技术从甜菜根内检测到了G.mosseae,表明G.mosseae侵染甜菜根系.

  4. Advances in the research of tabacoo arbuscular mycorrhizas fungi%烟草丛枝菌根(AM)研究进展

    Institute of Scientific and Technical Information of China (English)

    王茂胜; 卫亚丽

    2007-01-01

    丛枝菌根真菌(Arbuscular mycorrhizas fungi)作为生物调节剂、生物肥料和生物防治剂,在持续农业和自然生态中的作用越来越受到人们的重视.丛枝菌根真菌不仅能增强烟草对矿质元素的吸收、提高烟草抗逆性、增强抗病性、改善烟草根际微环境,而且能提高其产量和改善品质.本文从烟草丛枝菌根真菌资源、丛枝菌根对烟草的主要作用、丛枝菌根对植烟土壤主要作用3个方面简要综述了烟草丛枝菌根的研究进展.

  5. Dinâmica e contribuição da micorriza arbuscular em sistemas de produção com rotação de culturas Dynamics and contribution of arbuscular mycorrhiza in culture systems with crop rotation

    Directory of Open Access Journals (Sweden)

    Jeanne Christine Claessen de Miranda

    2005-10-01

    Full Text Available Rotação de culturas e variações sazonais podem promover alterações quantitativas e qualitativas na comunidade de fungos micorrízicos arbusculares nativos e na formação da micorriza arbuscular. Essa dinâmica foi avaliada, em campo, num Latossolo Vermelho, em relação ao tempo de cultivo e variação sazonal, em sistemas de rotação de culturas. Em casa de vegetação, avaliou-se, em solo proveniente da área experimental, a contribuição da micorriza arbuscular no crescimento de soja e capim-andropógon utilizados na rotação. O número de esporos dos fungos aumentou no solo cultivado. O número de esporos e o porcentual de colonização radicular, inicialmente maiores sob pastagem, variaram de acordo com o tempo de cultivo, as estações seca e chuvosa, a cultura e o sistema de rotação utilizados. O número de gêneros e espécies aumentou com o tempo de cultivo e manejo de culturas e foi maior sob culturas anuais em rotação. A presença dos fungos no solo contribuiu no crescimento da soja e do capim-andropógon em 53% e 95%, respectivamente. A cultura e o sistema de cultivo são fatores determinantes para o enriquecimento do sistema com micorriza arbuscular.Crop rotation and seasonal variations can promote quantitative and qualitative changes in the indigenous arbuscular mycorrhizal fungi population in the soil and arbuscular mycorrhiza establishment. These fungi dynamics were evaluated in the field, in a Red Latosol, in relation to cropping time, seasonal variation and rotation systems. The contribution of arbuscular mycorrhiza to the growth of andropogon grass and soybean, which were used in the systems, was evaluated in a greenhouse experiment using soil from the experimental area. The number of spores of the fungi increased in the cultivated soil. The spores number and percent root colonization varied according to cropping time, soil moisture, crops and rotation system and were, initially, higher under pasture. The number

  6. Ocorrência de micorrizas arbusculares e da bactéria diazotrófica Acetobacter diazotrophicus em cana-de-açúcar Occurrence of arbuscular mycorrhizae and bacterium Acetobacter diazotrophicus in sugar cane

    Directory of Open Access Journals (Sweden)

    Veronica Massena Reis

    1999-10-01

    Full Text Available Foi avaliada a ocorrência e a distribuição de espécies de fungos micorrízicos arbusculares (FMAs e Acetobacter diazotrophicus em plantios de cana-de-açúcar em diferentes tipos de manejo nos Estados do Rio de Janeiro e Pernambuco. Foram feitas 35 coletas de amostras de solo da rizosfera e de raízes de 14 variedades de cana-de-açúcar para extração de esporos e isolamento da bactéria. O número de esporos variou de 18 a 2.070/100 mL de solo, e os maiores número e diversidade de espécies foram verificados nos canaviais de Campos, RJ, especialmente naqueles que não adotam a queima do palhiço. As espécies predominantes nas três localidades amostradas foram: Acaulospora sp., Scutellospora heterogama, Glomus etunicatum, Glomus occultum e Gigaspora margarita. A. diazotrophicus estava presente nas amostras de raízes colhidas em canaviais de Campos, com exceção de uma coleta de cana-de-açúcar plantada num solo usado como bacia de sedimentação de vinhaça. Não foi possível isolar essa bactéria a partir de esporos desinfestados dos FMAs nativos, apenas dos esporos lavados com água estéril.The occurrence and distribution of species of arbuscular mycorrhizae fungi and Acetobacter diazotrophicus in sugar cane (Saccharum officinarum grown in different regimes of crop management in the States of Rio de Janeiro and Pernambuco, Brazil, were studied. Thirty five samples of the rhizosphere soil and roots were collected from 14 varieties of sugar cane for the extraction of spores and isolation of the bacterium. The number of spores varied from 18 to 2,070 per 100 mL of soil, and the greatest diversity of fungal species was found in the sugarcane fields of Campos (Rio de Janeiro State, especially in those where the sugarcane trash was not burned at harvest. The predominant species found in the three localities sampled were: Scutellospora heterogama, Glomus etunicatum, Glomus occultum, Acaulospora sp. and Gigaspora margarita. A

  7. Effects of arbuscular mycorrhizae on growth and mineral nutrition of greenhouse propagated fruit trees from diverse geographic provenances

    Directory of Open Access Journals (Sweden)

    Guissou, T.

    2016-01-01

    Full Text Available Description of the subject. Arbuscular mycorrhizal (AM fungi are known to promote plant growth by enhancing mineral uptake in nutrient deficient soils. These beneficial effects on plant growth may vary considerably between cultivars of a given species and between plant species originating from different locations. Objectives. The present experiment evaluated the response of three Sahelian fruit trees: néré (Parkia biglobosa [Jacq.] G.Don, tamarind (Tamarindus indica L., and jujube (Ziziphus mauritiana Lam., originating from five different geographic provenances, to mycorrhizal colonization, evaluate their respective mycorrhizal dependency (MD and analyze their leaf and stem mineral composition. Method. Trees were cultivated in a nursery on pre-sterilized soil substrate low in available P (2.18 μg·g-1 with or without inoculum of Glomus aggregatum (Schenck & Smith emend. Koske. The experiment was arranged in a factorial design for each fruit tree species separately: 5 provenances x 2 AM treatments (inoculated and non-inoculated [control] with 10 replicates per treatment. Plants were harvested six months after inoculation and different parameters were measured. Results. Overall, the results showed significant provenance variations in the plant response to mycorrhizal inoculation. Néré mycorrhizal plants, from two seed sources, tamarind and jujube plants from one seed source had significant higher dry weight and shoot height than those from other provenances. Jujube plants from 3 out of the 5 provenances showed significant higher MD. It then appears that seed provenance happened to be determinant even though AM-root colonization levels (80-90% do not vary much from one provenance to another. In all cases, the fruit trees benefited from AM fungi with increased N, P and K mineral uptake in aerial parts. In particular P uptake was proportional to MD concentration in AM-jujube plants. Conclusions. These results demonstrate the importance of

  8. Functional diversity in arbuscular mycorrhizas: Exploitation of soil patches with different phosphate enrichment differs among fungal species

    DEFF Research Database (Denmark)

    Cavagnaro, T.R.; Smith, F.A.; Smith, S.E.;

    2005-01-01

    Most terrestrial plant species form associations with arbuscular mycorrhizal fungi (AMF) that transfer soil P to the plant via their external hyphae. The distribution of nutrients in soils is typically patchy (heterogeneous) but little is known about the ability of AMF to exploit P patches in soi...... by decreased P uptake by other parts of the mycelium. This is the first demonstration of variation in growth and nutrient uptake by an AMF as influenced by a localized P enrichment of the soil. The results are discussed in the context of functional diversity of AMF....

  9. Effect of mutations in the pea genes Sym33 and Sym40. I. Arbuscular mycorrhiza formation and function.

    Science.gov (United States)

    Jacobi, Lidia M; Petrova, Olesia S; Tsyganov, Viktor E; Borisov, Alexey Y; Tikhonovich, Igor A

    2003-03-01

    Two pea (Pisum sativum L.) symbiotic mutants SGEFix(-)-1 (sym40) and SGEFix(-)-2 (sym33) with abnormalities in infection thread development and function in symbiotic root nodules have been characterised in terms of mycorrhizal colonisation of roots, shoot and root biomass accumulation and shoot and root phosphorus (P) content. The mutation in gene sym33 decreased mycorrhizal colonisation of roots (except arbuscule abundance in mycorrhizal root fragments, which increased) but did not change the effectiveness of mycorrhiza function. The mutation in sym40 did not affect either of these processes. Both mutants showed differences in plant development compared with the wild-type line SGE. The mutants had delayed flowering and pod ripening, and shoot/root biomass ratios and P accumulation also differed from those of SGE. These observations suggest that the gene mutations cause systemic changes in plant development.

  10. Gene expression analyses in tomato near isogenic lines provide evidence for ethylene and abscisic acid biosynthesis fine-tuning during arbuscular mycorrhiza development.

    Science.gov (United States)

    Fracetto, Giselle Gomes Monteiro; Peres, Lázaro Eustáquio Pereira; Lambais, Marcio Rodrigues

    2017-07-01

    Plant responses to the environment and microorganisms, including arbuscular mycorrhizal fungi, involve complex hormonal interactions. It is known that abscisic acid (ABA) and ethylene may be involved in the regulation of arbuscular mycorrhiza (AM) and that part of the detrimental effects of ABA deficiency in plants is due to ethylene overproduction. In this study, we aimed to determine whether the low susceptibility to mycorrhizal colonization in ABA-deficient mutants is due to high levels of ethylene and whether AM development is associated with changes in the steady-state levels of transcripts of genes involved in the biosynthesis of ethylene and ABA. For that, tomato (Solanum lycopersicum) ethylene overproducer epinastic (epi) mutant and the ABA-deficient notabilis (not) and sitiens (sit) mutants, in the same Micro-Tom (MT) genetic background, were inoculated with Rhizophagus clarus, and treated with the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG). The development of AM, as well as the steady-state levels of transcripts involved in ethylene (LeACS2, LeACO1 and LeACO4) and ABA (LeNCED) biosynthesis, was determined. The intraradical colonization in epi, not and sit mutants was significantly reduced compared to MT. The epi mutant completely restored the mycorrhizal colonization to the levels of MT with the application of 10 µM of AVG, probably due to the inhibition of the ACC synthase gene expression. The steady-state levels of LeACS2 and LeACO4 transcripts were induced in mycorrhizal roots of MT, whereas the steady-state levels of LeACO1 and LeACO4 transcripts were significantly induced in sit, and the steady-state levels of LeNCED transcripts were significantly induced in all genotypes and in mycorrhizal roots of epi mutants treated with AVG. The reduced mycorrhizal colonization in sit mutants seems not to be limited by ethylene production via ACC oxidase regulation. Both ethylene overproduction and ABA deficiency impaired AM fungal

  11. Structure and function of arbuscular mycorrhiza: A review%丛枝菌根结构与功能研究进展

    Institute of Scientific and Technical Information of China (English)

    田蜜; 陈应龙; 李敏; 刘润进

    2013-01-01

    Arbuscular mycorrhiza (AM) is one of the most widely distributed and the most important mutualistic symbionts in terrestrial ecosystems,playing a significant role in enhancing plant resistance to stresses,remediating polluted environments,and maintaining ecosystem stabilization and sustainable productivity.The structural characteristics of AM are the main indicators determining the mycorrhizal formation in root system,and have close relations to the mycorrhizal functions.This paper summarized the structural characteristics of arbuscules,vesicles,mycelia and invasion points of AM,and analyzed the relationships between the Arum (A) type arbuscules,Paris (P) type arbuscules,vesicles,and external mycelia and their functions in improving plant nutrient acquisition and growth,enhancing plant resistance to drought,waterlogging,salinity,high temperature,diseases,heavy metals toxicity,and promoting toxic organic substances decomposition and polluted and degraded soil remediation.The factors affecting the AM structure and functions as well as the action mechanisms of mycorrhizal functions were also discussed.This review would provide a basis for the systemic study of AM structural characteristics and functional mechanisms and for evaluating and screening efficient AM fungal species.%丛枝菌根(arbuscular mycorrhiza,AM)是陆地生态系统中分布最广泛、最重要的互惠共生体之一,对提高植物抗逆性、修复污染生境、保持生态系统稳定与可持续生产力的作用显著.AM结构特征是判断菌根形成的主要指标,与其功能密切相关.本文总结了AM丛枝结构、泡囊结构、菌丝结构和侵入点结构等发育特征;分析了A型丛枝结构、P型丛枝结构、泡囊结构和根外菌丝结构与促进寄主植物养分吸收和生长、提高植物抗旱性、耐涝性、耐盐性、抗高温、拮抗病原物、提高植物抗病性、抗重金属毒性、分解有毒有机物、修复污染与退化土壤等功能

  12. Overlaps in the Transcriptional Profiles of Medicago truncatula Roots Inoculated with Two Different Glomus Fungi Provide Insights into the Genetic Program Activated during Arbuscular Mycorrhiza1[w

    Science.gov (United States)

    Hohnjec, Natalija; Vieweg, Martin F.; Pühler, Alfred; Becker, Anke; Küster, Helge

    2005-01-01

    Arbuscular mycorrhiza (AM) is a widespread symbiotic association between plants and fungal microsymbionts that supports plant development under nutrient-limiting and various stress conditions. In this study, we focused on the overlapping genetic program activated by two commonly studied microsymbionts in addition to identifying AM-related genes. We thus applied 16,086 probe microarrays to profile the transcriptome of the model legume Medicago truncatula during interactions with Glomus mosseae and Glomus intraradices and specified a total of 201 plant genes as significantly coinduced at least 2-fold, with more than 160 being reported as AM induced for the first time. Several hundred genes were additionally up-regulated during a sole interaction, indicating that the plant genetic program activated in AM to some extent depends on the colonizing microsymbiont. Genes induced during both interactions specified AM-related nitrate, ion, and sugar transporters, enzymes involved in secondary metabolism, proteases, and Kunitz-type protease inhibitors. Furthermore, coinduced genes encoded receptor kinases and other components of signal transduction pathways as well as AM-induced transcriptional regulators, thus reflecting changes in signaling. By the use of reporter gene expression, we demonstrated that one member of the AM-induced gene family encoding blue copper binding proteins (MtBcp1) was both specifically and strongly up-regulated in arbuscule-containing regions of mycorrhizal roots. A comparison of the AM expression profiles to those of nitrogen-fixing root nodules suggested only a limited overlap between the genetic programs orchestrating root endosymbioses. PMID:15778460

  13. Influência da colonização micorrízica arbuscular sobre a nutrição do quiabeiro Influence of arbuscular mycorrhiza fungi on the nutrition of okra plant

    Directory of Open Access Journals (Sweden)

    Ricardo Luís Louro Berbara

    1999-09-01

    Full Text Available Foram estudados em casa de vegetação alguns parâmetros de crescimento em plantas de quiabo (Abelmoschus esculentus (L. Moench cv. Piranema colonizadas por dois grupos de fungos micorrízicos arbusculares, com o objetivo de determinar a influência dos inóculos na nutrição e morfologia radicular do quiabeiro. Um grupo continha apenas esporos de Acaulospora longula (A enquanto o outro, esporos de oito espécies: Glomus occultum, Glomus aggregatum, Glomus microcarpum, Acaulospora longula, Acaulospora morrowae, Sclerocystis coremioides, Sclerocystis sinuosa, Scutellospora pellucida. As plantas foram submetidas a três níveis de P (0, 10 e 60 kg ha-1 de P2O5 e coletadas em três diferentes idades (22, 32 e 47 dias, com quatro repetições para cada tratamento. Foi determinado o acúmulo de N, P, K, e Mg na raiz e parte aérea, bem como o influxo médio desses elementos e a área radicular. Os resultados indicaram, além da resposta positiva do quiabeiro ao P, uma maior eficiência da inoculação com mistura de espécies apesar de o influxo médio, determinado aos 47 dias, apresentar maiores valores para o tratamento com A. longula.An experiment was carried out in greenhouse to determine the influence of inoculation of two groups of arbuscular mycorrhizae on the nutrition and radicular morphology of the okra plant (Abelmoschus esculentus (L. Moench cv. Piranema. One group had only Acaulospora longula spores and the other a spore mixture of eight species: Glomus occultum, Glomus aggregatum, Glomus microcarpum, Acaulospora longula, Acaulospora morrowae, Sclerocystis coremioides, Sclerocystis sinuosa, Scutellospora pellucida. The experiment was held in greenhouse conditions with three levels of P (0, 10 and 60 kg ha-1 of P2O5, three samplings dates (22, 32 and 47 days and four replications. The accumulation of N, P, K, Ca and Mg in roots and shoots, root area and their influx ratio were determined. The results made evident that the mixture of

  14. Rhizosphere bacterial community composition responds to arbuscular mycorrhiza, but not to reductions in microbial activity induced by foliar cutting

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård; Henry, Frédéric; Rangel-Castro, J. Ignacio

    2008-01-01

    Differences in bacterial community composition (BCC) between bulk and rhizosphere soil and between rhizospheres of different plant species are assumed to be strongly governed by quantitative and qualitative rhizodeposit differences. However, data on the relationship between rhizodeposit amounts...... and BCC are lacking. Other soil microorganisms, e.g. arbuscular mycorrhizal fungi (AMF), may also influence BCC. We simulated foliar herbivory (cutting) to reduce belowground carbon allocation and rhizodeposition of pea plants grown either with or without AMF. This reduced soil respiration, rhizosphere...... microbial biomass and bacteriovorous protozoan abundance, whereas none of these were affected by AMF. After labelling plants with 13CO2, root and rhizosphere soil 13C enrichment of cut plants were reduced to a higher extent (24-46%) than shoot 13C enrichment (10-24%). AMF did not affect 13C enrichment...

  15. Evolution of mycorrhiza systems

    Science.gov (United States)

    Cairney, J. W. G.

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200million years ago) and ericoid mycorrhizas (about 100million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change.

  16. 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...

  17. Gate crashing arbuscular mycorrhizas: in vivo imaging shows the extensive colonization of both symbionts by Trichoderma atroviride.

    Science.gov (United States)

    Lace, Beatrice; Genre, Andrea; Woo, Sheridan; Faccio, Antonella; Lorito, Matteo; Bonfante, Paola

    2015-02-01

    Plant growth-promoting fungi include strains of Trichoderma species that are used in biocontrol, and arbuscular mycorrhizal (AM) fungi, that enhance plant nutrition and stress resistance. The concurrent interaction of plants with these two groups of fungi affects crop performance but has only been occasionally studied so far. Using in vivo imaging of green fluorescent protein-tagged lines, we investigated the cellular interactions occurring between Trichoderma atroviride PKI1, Medicago truncatula and two Gigaspora species under in vitro culture conditions. Trichoderma atroviride did not activate symbiotic-like responses in the plant cells, such as nuclear calcium spiking or cytoplasmic aggregations at hyphal contact sites. Furthermore, T. atroviride parasitized G. gigantea and G. margarita hyphae through localized wall breaking and degradation - although this was not associated with significant chitin lysis nor the upregulation of two major chitinase genes. Trichoderma atroviride colonized broad areas of the root epidermis, in association with localized cell death. The infection of both symbionts was also observed when T. atroviride was applied to a pre-established AM symbiosis. We conclude that - although this triple interaction is known to improve plant growth in agricultural environments - in vitro culture demonstrate a particularly aggressive mycoparasitic and plant-colonizing behaviour of a biocontrol strain of Trichoderma.

  18. Effects of heavy metals and arbuscular mycorrhiza on the leaf proteome of a selected poplar clone: a time course analysis.

    Directory of Open Access Journals (Sweden)

    Guido Lingua

    Full Text Available Arbuscular mycorrhizal (AM fungi establish a mutualistic symbiosis with the roots of most plant species. While receiving photosynthates, they improve the mineral nutrition of the plant and can also increase its tolerance towards some pollutants, like heavy metals. Although the fungal symbionts exclusively colonize the plant roots, some plant responses can be systemic. Therefore, in this work a clone of Populus alba L., previously selected for its tolerance to copper and zinc, was used to investigate the effects of the symbiosis with the AM fungus Glomus intraradices on the leaf protein expression. Poplar leaf samples were collected from plants maintained in a glasshouse on polluted (copper and zinc contaminated or unpolluted soil, after four, six and sixteen months of growth. For each harvest, about 450 proteins were reproducibly separated on 2DE maps. At the first harvest the most relevant effect on protein modulation was exerted by the AM fungi, at the second one by the metals, and at the last one by both treatments. This work demonstrates how importantly the time of sampling affects the proteome responses in perennial plants. In addition, it underlines the ability of a proteomic approach, targeted on protein identification, to depict changes in a specific pattern of protein expression, while being still far from elucidating the biological function of each protein.

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

    Science.gov (United States)

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

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

  20. Influence of arbuscular mycorrhiza on growth and reproductive response of plants under water deficit: a meta-analysis.

    Science.gov (United States)

    Jayne, Benjamin; Quigley, Martin

    2014-02-01

    Despite a large body of literature that describes the effects of arbuscular mycorrhizal colonization on plant response to water deficit, reviews of these works have been mainly in narrative form, and it is therefore difficult to quantify the magnitude of the effect. We performed a meta-analysis to examine the effect of mycorrhizal colonization on growth and yield of plants exposed to water deficit stress. Data were compared in the context of annual vs. perennial plants, herbaceous vs. woody plants, field vs. greenhouse conditions, degree of stress, functional group, regions of plant growth, and mycorrhizal and host species. We found that, in terms of biomass measurements, mycorrhizal plants have better growth and reproductive response under water stress compared to non-mycorrhizal plants. When variables such as habit, life cycle, or water stress level are considered, differences in mycorrhizal effect on plant growth between variables are observed. While growth of both annual and perennial plants is improved by symbiosis, perennials respond more favorably to colonization than annuals. Overall, our meta-analysis reveals a quantifiable corroboration of the commonly held view that, under water-deficit conditions, plants colonized by mycorrhizal fungi have better growth and reproductive response than those that are not.

  1. Enhanced hyphal growth of arbuscular mycorrhizae by root exudates derived from high R/FR treated Lotus japonicus.

    Science.gov (United States)

    Nagata, Maki; Yamamoto, Naoya; Miyamoto, Taro; Shimomura, Aya; Arima, Susumu; Hirsch, Ann M; Suzuki, Akihiro

    2016-06-02

    Red/Far Red (R/FR) sensing positively influences the arbuscular mycorrhizal (AM) symbiosis of both legume and nonlegume plants through jasmonic acid (JA) and strigolactone signaling. We previously reported that root exudates obtained from high R/FR-grown plants contained more strigolactone than low R/FR-grown plants. To determine whether JA and JA derivatives were secreted from roots, we investigated the expression levels of JA-responsive genes in L. japonicus Miyakojima MG20 plants treated with root exudates prepared from either high or low R/FR light-treated plants. The root exudates from high R/FR light-treated plants were found to enhance the expression levels of JA-responsive genes significantly. Moreover, exogenous JA increased AM fungal hyphal elongation as did the root exudates derived from high R/FR-grown L. japonicus plants. We conclude that increased JA accumulation and secretion into root exudates from high R/FR light-grown plants is the best explanation for increased colonization and enhanced mycorrhization under these conditions.

  2. Arbuscular mycorrhizas enhance nutrient uptake in different wheat genotypes at high salinity levels under field and greenhouse conditions.

    Science.gov (United States)

    Mardukhi, Baran; Rejali, Farhad; Daei, Gudarz; Ardakani, Mohammad Reza; Malakouti, Mohammad Javad; Miransari, Mohammad

    2011-07-01

    Since most experiments regarding the symbiosis between arbuscular mycorrhizal (AM) fungi and their host plants under salinity stress have been performed only under greenhouse conditions, this research work was also conducted under field conditions. The effects of three AM species including Glomus mosseae, G. etunicatum and G. intraradices on the nutrient uptake of different wheat cultivars (including Roshan, Kavir and Tabasi) under field and greenhouse (including Chamran and Line 9) conditions were determined. At field harvest, the concentrations of N, Ca, Mg, Fe, Cu, and Mn, and at greenhouse harvest, plant growth, root colonization and concentrations of different nutrients including N, K, P, Ca, Mg, Mn, Cu, Fe, Zn, Na and Cl were determined. The effects of wheat cultivars on the concentrations of N, Ca, and Mn, and of all nutrients were significant at field and greenhouse conditions, respectively. In both experiments, AM fungi significantly enhanced the concentrations of all nutrients including N, K, P, Ca, Mg, Mn, Cu, Fe, Zn, Na and Cl. The synergistic and enhancing effects of co-inoculation of AM species on plant growth and the inhibiting effect of AM species on Na(+) rather than on Cl(-) uptake under salinity are also among the important findings of this research work. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  3. Inoculation with arbuscular mycorrhizae does not improve 137Cs uptake in crops grown in the Chernobyl region.

    Science.gov (United States)

    Vinichuk, M; Mårtensson, A; Rosén, K

    2013-12-01

    Methods for cleaning up radioactive contaminated soils are urgently needed. In this study we investigated whether the use of arbuscular mycorrhizal (AM) fungi can improve (137)Cs uptake by crops. Barley, cucumber, perennial ryegrass, and sunflower were inoculated with AM fungi and grown in low-level radionuclide contaminated soils in a field experiment 70 km southwest of Chernobyl, Ukraine, during two successive years (2009-2010). Roots of barley, cucumber and sunflower plants were slightly or moderately infected with AM fungus and root infection frequency was negatively or non-correlated with (137)Cs uptake by plants. Roots of ryegrass were moderately infected with AM fungus and infection frequency was moderately correlated with (137)Cs uptake by ryegrass. The application of AM fungi to soil in situ did not enhance radionuclide plant uptake or biomass. The responsiveness of host plants and AM fungus combination to (137)Cs uptake varied depending on the soil, although mycorrhization of soil in the field was conditional and did not facilitate the uptake of radiocesium. The total amount of (137)Cs uptake by plants growing on inoculated soil was equal to amounts in plant cultivated on non-inoculated soil. Thus, the use of AM fungi in situ for bioremediation of soil contaminated with a low concentration of (137)Cs could not be recommended. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Plant growth responses to elevated atmospheric CO2 are increased by phosphorus sufficiency but not by arbuscular mycorrhizas

    Science.gov (United States)

    Jakobsen, Iver; Smith, Sally E.; Smith, F. Andrew; Watts-Williams, Stephanie J.; Clausen, Signe S.; Grønlund, Mette

    2016-01-01

    Capturing the full growth potential in crops under future elevated CO2 (eCO2) concentrations would be facilitated by improved understanding of eCO2 effects on uptake and use of mineral nutrients. This study investigates interactions of eCO2, soil phosphorus (P), and arbuscular mycorrhizal (AM) symbiosis in Medicago truncatula and Brachypodium distachyon grown under the same conditions. The focus was on eCO2 effects on vegetative growth, efficiency in acquisition and use of P, and expression of phosphate transporter (PT) genes. Growth responses to eCO2 were positive at P sufficiency, but under low-P conditions they ranged from non-significant in M. truncatula to highly significant in B. distachyon. Growth of M. truncatula was increased by AM at low P conditions at both CO2 levels and eCO2×AM interactions were sparse. Elevated CO2 had small effects on P acquisition, but enhanced conversion of tissue P into biomass. Expression of PT genes was influenced by eCO2, but effects were inconsistent across genes and species. The ability of eCO2 to partly mitigate P limitation-induced growth reductions in B. distachyon was associated with enhanced P use efficiency, and requirements for P fertilizers may not increase in such species in future CO2-rich climates. PMID:27811084

  5. Effects of Heavy Metals and Arbuscular Mycorrhiza on the Leaf Proteome of a Selected Poplar Clone: A Time Course Analysis

    Science.gov (United States)

    Lingua, Guido; Bona, Elisa; Todeschini, Valeria; Cattaneo, Chiara; Marsano, Francesco; Berta, Graziella; Cavaletto, Maria

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi establish a mutualistic symbiosis with the roots of most plant species. While receiving photosynthates, they improve the mineral nutrition of the plant and can also increase its tolerance towards some pollutants, like heavy metals. Although the fungal symbionts exclusively colonize the plant roots, some plant responses can be systemic. Therefore, in this work a clone of Populus alba L., previously selected for its tolerance to copper and zinc, was used to investigate the effects of the symbiosis with the AM fungus Glomus intraradices on the leaf protein expression. Poplar leaf samples were collected from plants maintained in a glasshouse on polluted (copper and zinc contaminated) or unpolluted soil, after four, six and sixteen months of growth. For each harvest, about 450 proteins were reproducibly separated on 2DE maps. At the first harvest the most relevant effect on protein modulation was exerted by the AM fungi, at the second one by the metals, and at the last one by both treatments. This work demonstrates how importantly the time of sampling affects the proteome responses in perennial plants. In addition, it underlines the ability of a proteomic approach, targeted on protein identification, to depict changes in a specific pattern of protein expression, while being still far from elucidating the biological function of each protein. PMID:22761694

  6. Arbuscular mycorrhiza infection enhances the growth response of Lolium perenne to elevated atmospheric pCO(2).

    Science.gov (United States)

    Hartwig, U A; Wittmann, P; Braun, R; Hartwig-Räz, B; Jansa, J; Mozafar, A; Lüscher, A; Leuchtmann, A; Frossard, E; Nösberger, J

    2002-05-01

    Elevated atmospheric pCO(2) increases the C-availability for plants and thus leads to a comparable increase in plant biomass production and nutrient demand. Arbuscular mycorrhizal fungi (AMF) are considered to play an important role in the nutrient uptake of plants as well as to be a significant C-sink. Therefore, an increased colonization of plant roots by AMF is expected under elevated atmospheric pCO(2). To test these hypotheses, Lolium perenne L. plants were grown from seeds in a growth chamber in pots containing a silica sand/soil mixture for 9 weeks with and without inoculation with Glomus intraradices (Schenck and Smith). The growth response of plants at two different levels of N fertilization (1.5 or 4.5 mM) combined with ambient (35 Pa) and elevated atmospheric pCO(2) (60 Pa) was compared. The inoculation with G. intraradices, the elevated atmospheric pCO(2) and the high N fertilization treatment all led to an increased plant biomass production of 16%, 20% and 49%, respectively. AMF colonization and high N fertilization increased the plant growth response to elevated atmospheric pCO(2); the plant growth response to high N fertilization was also increased by AMF colonization. The root/shoot ratio was reduced by high N fertilization or elevated atmospheric pCO(2), but was not affected by AMF colonization. The unchanged specific leaf area indicated that if AMF colonization represented an increased C-sink, this was fully covered by the plant. Elevated atmospheric pCO(2) strongly increased AMF colonization (60%) while the high N fertilization had a slightly negative effect. AMF colonization neither improved the N nor P nutrition status, but led to an improved total P uptake. The results underline the importance of AMF for the response of grassland ecosystems to elevated atmospheric pCO(2).

  7. Arbuscular mycorrhizae alleviate negative effects of zinc oxide nanoparticle and zinc accumulation in maize plants--A soil microcosm experiment.

    Science.gov (United States)

    Wang, Fayuan; Liu, Xueqin; Shi, Zhaoyong; Tong, Ruijian; Adams, Catharine A; Shi, Xiaojun

    2016-03-01

    ZnO nanoparticles (NPs) are considered an emerging contaminant when in high concentration, and their effects on crops and soil microorganisms pose new concerns and challenges. Arbuscular mycorrhizal (AM) fungi (AMF) form mutualistic symbioses with most vascular plants, and putatively contribute to reducing nanotoxicity in plants. Here, we studied the interactions between ZnO NPs and maize plants inoculated with or without AMF in ZnO NPs-spiked soil. ZnO NPs had no significant adverse effects at 400 mg/kg, but inhibited both maize growth and AM colonization at concentrations at and above 800 mg/kg. Sufficient addition of ZnO NPs decreased plant mineral nutrient acquisition, photosynthetic pigment concentrations, and root activity. Furthermore, ZnO NPs caused Zn concentrations in plants to increase in a dose-dependent pattern. As the ZnO NPs dose increased, we also found a positive correlation with soil diethylenetriaminepentaacetic acid (DTPA)-extractable Zn. However, AM inoculation significantly alleviated the negative effects induced by ZnO NPs: inoculated-plants experienced increased growth, nutrient uptake, photosynthetic pigment content, and SOD activity in leaves. Mycorrhizal plants also exhibited decreased ROS accumulation, Zn concentrations and bioconcentration factor (BCF), and lower soil DTPA-extractable Zn concentrations at high ZnO NPs doses. Our results demonstrate that, at high contamination levels, ZnO NPs cause toxicity to AM symbiosis, but AMF help alleviate ZnO NPs-induced phytotoxicity by decreasing Zn bioavailability and accumulation, Zn partitioning to shoots, and ROS production, and by increasing mineral nutrients and antioxidant capacity. AMF may play beneficial roles in alleviating the negative effects and environmental risks posed by ZnO NPs in agroecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. ANATOMY OF ARBUSCULAR MYCORRIZA FUNGUS (AMF ACAULOSPORA SCROBICULATU ON ROOTS OF THE SHEA TREE VITELLARIA PARADOXA IN NIGERIA

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    Odigie E.E.

    2013-09-01

    Full Text Available The discovery of root nodules on healthy Shea tree seedlings revealed the mutualistic associations between root nodules, arbuscular mycorrhiza fungus Acaulospora scrobiculatu and the host plant. The root was transversally sectioned to illustrate its structure, detect the presence of mycorrhiza colonization, intact cells of healthy tissues, impact of the mycorrhiza on host tissue and changes resulting from presence of the colonization. The root with mycorrhiza application was thicker and bigger when compared to the control treatment. The anatomical study revealed that the root contains epidemis, exodemis, cortex, early metaxylem and the pith. The nodule contains fungus hyphae which were seen growing outward and inward of the host without causing damage to the host cells. This mycorrhiza colonization resulted in enlargement of the host cells possibly to facilitate and improve the nutritional uptake of both partners.

  9. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.).

    Science.gov (United States)

    Yang, Ruyi; Yu, Guodong; Tang, Jianjun; Chen, Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species (Solidago canadensis L.) in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels (control, 300, and 600 mg/kg soil) were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum). The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization (root length colonized, RLC%) but did not affect spore numbers, N (including total N and 15N) and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant (root and rhizome). The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

  10. Effectiveness of native arbuscular mycorrhiza on the growth of four tree forest species from the Santa Marta Mountain, Veracruz (Mexico

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    Yolanda Retama-Ortiz

    2017-05-01

    Full Text Available Aim of the study: The aim of this work was to isolate consortia of arbuscular mycorrhizal fungi (AMF associated to Liquidambar styraciflua in soils of the Santa Marta Mountain in Veracruz, and to select highly effective mycorrhizal consortia on promoting the growth of four tree forest species with economic and ecological importance. Area of study: Santa Marta Mountain, inside the buffer area of the Los Tuxtlas Biological Reserve in Veracruz (México. Materials and methods: Ten composite samples of rhizosphere soil were collected from L. styraciflua trees of 13-15 cm DBH (diameter at breast height. Roots were fixed in FAA solution to determine the mycorrhizal colonization percentage, the abundance of morphospecies, and its effectiveness in promoting the growth of L. styraciflua, Terminalia amazonia, Cordia alliodora, and Cojoba arborea. Soil physical and chemical characteristics were also analysed, and soil type recognition was performed with the Reference Base for Soil FAO-ISRIC World-SICS. Mycorrhizal colonization was determined by the method of clearing and staining roots with trypan blue; total percentage of colonization was estimated by the Linderman-Biermann method. Spores were extracted for counting and identifying morphospecies from each soil sample, those with more effectiveness were selected and inoculated in the four tree species, based upon a completely random design there were evaluated height, number of leaves, total dry weight and foliar area. Main results: Average mycorrhizal colonization percentage was 45% from natural conditions, samples one and four showed 80% of AMF-colonization. Average number of spores was 617 in 100 g-1 of dry soil. Forty-seven AMF-morphospecies were identified. After eight months significant differences were observed in root colonization, height, number of leaves, total dry weight, leaf area and foliar analysis of N5+, P5+ and K+ on plants inoculated with rhizosphere samples of L. styraciflua. Terminalia

  11. A roadmap of cell-type specific gene expression during sequential stages of the arbuscular mycorrhiza symbiosis.

    Science.gov (United States)

    Hogekamp, Claudia; Küster, Helge

    2013-05-07

    About 80% of today's land plants are able to establish an arbuscular mycorrhizal (AM) symbiosis with Glomeromycota fungi to improve their access to nutrients and water in the soil. On the molecular level, the development of AM symbioses is only partly understood, due to the asynchronous development of the microsymbionts in the host roots. Although many genes specifically activated during fungal colonization have been identified, genome-wide information on the exact place and time point of their activation remains limited. In this study, we relied on a combination of laser-microdissection and the use of Medicago GeneChips to perform a genome-wide analysis of transcription patterns in defined cell-types of Medicago truncatula roots mycorrhized with Glomus intraradices. To cover major stages of AM development, we harvested cells at 5-6 and at 21 days post inoculation (dpi). Early developmental stages of the AM symbiosis were analysed by monitoring gene expression in appressorial and non-appressorial areas from roots harbouring infection units at 5-6 dpi. Here, the use of laser-microdissection for the first time enabled the targeted harvest of those sites, where fungal hyphae first penetrate the root. Circumventing contamination with developing arbuscules, we were able to specifically detect gene expression related to early infection events. To cover the late stages of AM formation, we studied arbusculated cells, cortical cells colonized by intraradical hyphae, and epidermal cells from mature mycorrhizal roots at 21 dpi. Taken together, the cell-specific expression patterns of 18014 genes were revealed, including 1392 genes whose transcription was influenced by mycorrhizal colonization at different stages, namely the pre-contact phase, the infection of roots via fungal appressoria, the subsequent colonization of the cortex by fungal hyphae, and finally the formation of arbuscules. Our cellular expression patterns identified distinct groups of AM-activated genes

  12. A roadmap of cell-type specific gene expression during sequential stages of the arbuscular mycorrhiza symbiosis

    Science.gov (United States)

    2013-01-01

    Background About 80% of today’s land plants are able to establish an arbuscular mycorrhizal (AM) symbiosis with Glomeromycota fungi to improve their access to nutrients and water in the soil. On the molecular level, the development of AM symbioses is only partly understood, due to the asynchronous development of the microsymbionts in the host roots. Although many genes specifically activated during fungal colonization have been identified, genome-wide information on the exact place and time point of their activation remains limited. Results In this study, we relied on a combination of laser-microdissection and the use of Medicago GeneChips to perform a genome-wide analysis of transcription patterns in defined cell-types of Medicago truncatula roots mycorrhized with Glomus intraradices. To cover major stages of AM development, we harvested cells at 5-6 and at 21 days post inoculation (dpi). Early developmental stages of the AM symbiosis were analysed by monitoring gene expression in appressorial and non-appressorial areas from roots harbouring infection units at 5-6 dpi. Here, the use of laser-microdissection for the first time enabled the targeted harvest of those sites, where fungal hyphae first penetrate the root. Circumventing contamination with developing arbuscules, we were able to specifically detect gene expression related to early infection events. To cover the late stages of AM formation, we studied arbusculated cells, cortical cells colonized by intraradical hyphae, and epidermal cells from mature mycorrhizal roots at 21 dpi. Taken together, the cell-specific expression patterns of 18014 genes were revealed, including 1392 genes whose transcription was influenced by mycorrhizal colonization at different stages, namely the pre-contact phase, the infection of roots via fungal appressoria, the subsequent colonization of the cortex by fungal hyphae, and finally the formation of arbuscules. Our cellular expression patterns identified distinct groups of AM

  13. Micorriza arbuscular e rizóbios no enraizamento e nutrição de mudas de angico-vermelho Arbuscular mycorrhizae and rhizobium in rooting and nutrition of angico-vermelho seedlings

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    Poliana Coqueiro Dias

    2012-12-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito da inoculação dos fungos micorrízicos arbusculares (FMAs e rizóbio no enraizamento, crescimento e nutrição de mudas de angico-vermelho (Anadenanthera macrocarpa (Benth Brenan propagadas via miniestaquia. Foram utilizadas seis progênies, das quais foram confeccionadas miniestacas com um par de folhas inteiras, bem como tubetes de 55 cm³ contendo substrato comercial Bioplant®. Foram testados quatro tratamentos: 8 kg m-3 de superfosfato simples (SS misturados ao substrato; 4 kg m-3 de SS misturados ao substrato; 4 kg m-3 de SS misturados ao substrato e adição de suspensão contendo rizóbios; e 4 kg m-3 de SS e adição de suspensão contendo rizóbios e 5 g de solo contendo esporos de FMAs. Não houve interação entre os tratamentos para percentagem de sobrevivência das miniestacas e percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, na saída da casa de vegetação (30 dias e da casa de sombra (40 dias, provavelmente em função do sistema radicular ainda estar em formação. Houve diferenças entre as progênies para percentagem de sobrevivência das miniestacas, percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, altura, diâmetro de colo e massa seca da parte aérea. As avaliações das características de crescimento das miniestacas enraizadas, principalmente com relação à sobrevivência a pleno sol (140 dias, evidenciam a eficiência dos rizóbios e FMAs na produção de mudas desta espécie. Conclui-se que a associação simbiótica com rizóbio e/ou FMA favorece a produção de mudas de A. macrocarpa via miniestaquia.The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizae fungi (AMF and rhizobium on rooting, growth and nutrition of seedlings of angico-red (Anadenanthera macrocarpa (Benth Brenan propagated by minicutting. Six progenies were used, of which were prepared

  14. Arbuscular mycorrhiza-induced shifts in foliar metabolism and photosynthesis mirror the developmental stage of the symbiosis and are only partly driven by improved phosphate uptake.

    Science.gov (United States)

    Schweiger, Rabea; Baier, Markus C; Müller, Caroline

    2014-12-01

    In arbuscular mycorrhizal (AM) plants, the plant delivers photoassimilates to the arbuscular mycorrhizal fungus (AMF), whereas the mycosymbiont contributes, in addition to other beneficial effects, to phosphate (PO4(3-)) uptake from the soil. Thereby, the additional fungal carbon (C) sink strength in roots and improved plant PO4(3-) nutrition may influence aboveground traits. We investigated how the foliar metabolome of Plantago major is affected along with the development of root symbiosis, whether the photosynthetic performance is affected by AM, and whether these effects are mediated by improved PO4(3-) nutrition. Therefore, we studied PO4(3-)-limited and PO4(3-)-supplemented controls in comparison with mycorrhizal plants at 20, 30, and 62 days postinoculation with the AMF Rhizophagus irregularis. Foliar metabolome modifications were determined by the developmental stage of symbiosis, with changes becoming more pronounced over time. In a well-established stage of mature mutualism, about 60% of the metabolic changes and an increase in foliar CO2 assimilation were unrelated to the significantly increased foliar phosphorus (P) content. We propose a framework relating the time-dependent metabolic changes to the shifts in C costs and P benefits for the plant. Besides P-mediated effects, the strong fungal C sink activity may drive the changes in the leaf traits.

  15. 丛枝菌根真菌对温室黄瓜生长及产量品质的影响%Effects of arbuscular mycorrhizas fungi on the growth, yield and quality of cucumber in greenhouse

    Institute of Scientific and Technical Information of China (English)

    秦海滨; 贺超兴; 张志斌; 王怀松; 任志雨

    2008-01-01

    以黄瓜为材料于温室盆栽条件下,研究丛枝菌根真菌(arbuscular mycorrhizas fungi,AMF)Glomous ver-siforme(GV)对黄瓜生长的影响.结果表明:苗期接种GV真菌后可提高黄瓜的株高,叶片中叶绿素a、叶绿素b、类胡萝卜素及可溶性糖含量;提高了黄瓜产量;黄瓜中总糖、干物质重量和维生素C、N、P、K、Zu、Cu等营养物质含量也有增加.

  16. Study on Arbuscular Mycorrhiza Colonizing of Caragana Korshinskii Kom in Gully Region of Loess Plateau%黄土沟壑区人工柠条丛枝菌根研究

    Institute of Scientific and Technical Information of China (English)

    刘永俊; 冯虎元

    2007-01-01

    丛枝菌根(Arbuscular mycorrhiza, AM)是大部分陆生高等植物与球囊菌门真菌形成的互惠共生体,具有重要的生理生态功能.通过显微观察和分子技术对黄土沟壑区的人工柠条丛枝菌根定殖情况进行研究,结果表明柠条能形成丛枝菌根结构,并具有较高的定殖率.相关性分析表明菌丝定殖率与泡囊定殖率、土壤水分含量呈正相关,丛枝定殖率与海拔呈负相关.

  17. 不同盐碱度土壤中AM菌根真菌群落结构组成及影响因子%Structure of Arbuscular mycorrhiza fungi community in soils with different salinity and influence factors

    Institute of Scientific and Technical Information of China (English)

    李丹; 高永超; 王加宁; 邱维忠; 迟建国

    2013-01-01

    In order to explore the Arbuscular mycorrhiza (AM) fungi diversity of the plant rhizosphere in the saline soil of the Yellow River Delta,four rhizosphere soil samples of Suaeda glauca Bge and Tamarix chinensis were collected from Gudong and Gudao oil fields in Dongying City for identification of the AM fungi communities.The results showed that Glomus was the dominant species in the saline soil accompanying with many unidentified fungi.The investigation of the mycorrhizal fungi community in different soil salinity showed that the AM fungal diversity in the rhizosphere soil of Suaeda glauca Bge was higher than that of Tamarix chinensis,and Gudong higher than Gudao.The correlation analysis showed that the ammonium nitrogen content had a significant negative relationship with AM fungal diversity.%为研究黄河三角洲盐渍土壤中植物根围AM菌根真菌多样性及影响多样性的因素,从东营孤东和孤岛油区采集碱蓬和柽柳植物的根围土壤,鉴定了4种土壤试样中丛枝菌根(Arbuscular mycorrhiza,AM)的群落组成.结果表明:球囊霉属(Glomus)是盐碱地中的优势种,同时还有许多未知真菌;考察不同盐碱度情况下菌根真菌群落结构差异,结果表明:碱蓬根围土壤中AM真菌的多样性高于柽柳,孤东根围土壤AM真菌多样性比孤岛高.相关分析表明,铵态氮含量与AM真菌多样性呈现显著负相关.

  18. Arbuscular Mycorrhizae-Trichoderma harzianum (Moniliaceae Interaction and Effects on Brachiaria decumbens (Poaceae’s Growth Interacción micorrizas arbusculares-Trichoderma harzianum (Moniliaceae y efectos sobre el crecimiento de Brachiaria decumbens (Poaceae

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    Morales Gutiérrez Esperanza

    2006-06-01

    Full Text Available The laboratory trial was made using native's Arbuscular Mycorrhizal Fungi (AMF sampled in Pennisetum clandestinum's rhizospheric soil obtained from Universidad Nacional de Colombia (Bogotá. Brachiaria decumbens was used as the host plant, growing in draining pots of steamed sandy soil supplemented with a complete nutritive solution.Four different treatments were tested to determine the kind of interaction between Arbuscular Mycorrhizal Fungi and Trichoderma harzianum and the effect of AMF plus T. harzianum on B. decumbens growth: plants with AMF inoculum, plants with T. harzianum, plants with AMF plus T. harzianum and uninoculated controls. Root colonization was decreased by T. harzianum, although AMF spores/g dry soil quantity was unaffected by this fungi. On the other hand, T. harzianum's population level (CFU /g dry soil decreased in presence of AMF. These results shows an interaction between AMF and T. harzianum and this interaction affects as AMF development as population density of T. harzianum. Based in the values of the plant growth parameters studied, is possible to conclude the AMF-T. harzianum interaction has a neutral effect on B. decumbens's growth.Se efectuó un ensayo en condiciones controladas utilizando hongos formadores de micorrizas arbusculares (HFMA nativos, provenientes de un suelo rizosférico de Pennisetum clandestinum de la Universidad Nacional de Colombia (Bogotá, manteniéndolos en plantas de Brachiaria decumbens creciendo sobre sustrato arenoso suplementado con solución nutritiva. Se evaluaron diferentes tratamientos: plantas con inóculo de HFMA, plantas con Trichoderma harzianum, plantas con HFMA+T. harzianum y plantas control no inoculadas, con el fin de determinar las posibles interacciones entre dichos microorganismos, así como su efecto sobre el crecimiento de B. decumbens. La presencia de T. harzianum disminuyó la colonización radicular por HFMA, aunque no afectó la cantidad de esporas de HFMA/g suelo

  19. RNA-seq Transcriptional Profiling of an Arbuscular Mycorrhiza Provides Insights into Regulated and Coordinated Gene Expression in Lotus japonicus and Rhizophagus irregularis.

    Science.gov (United States)

    Handa, Yoshihiro; Nishide, Hiroyo; Takeda, Naoya; Suzuki, Yutaka; Kawaguchi, Masayoshi; Saito, Katsuharu

    2015-08-01

    Gene expression during arbuscular mycorrhizal development is highly orchestrated in both plants and arbuscular mycorrhizal fungi. To elucidate the gene expression profiles of the symbiotic association, we performed a digital gene expression analysis of Lotus japonicus and Rhizophagus irregularis using a HiSeq 2000 next-generation sequencer with a Cufflinks assembly and de novo transcriptome assembly. There were 3,641 genes differentially expressed during arbuscular mycorrhizal development in L. japonicus, approximately 80% of which were up-regulated. The up-regulated genes included secreted proteins, transporters, proteins involved in lipid and amino acid metabolism, ribosomes and histones. We also detected many genes that were differentially expressed in small-secreted peptides and transcription factors, which may be involved in signal transduction or transcription regulation during symbiosis. Co-regulated genes between arbuscular mycorrhizal and root nodule symbiosis were not particularly abundant, but transcripts encoding for membrane traffic-related proteins, transporters and iron transport-related proteins were found to be highly co-up-regulated. In transcripts of arbuscular mycorrhizal fungi, expansion of cytochrome P450 was observed, which may contribute to various metabolic pathways required to accommodate roots and soil. The comprehensive gene expression data of both plants and arbuscular mycorrhizal fungi provide a powerful platform for investigating the functional and molecular mechanisms underlying arbuscular mycorrhizal symbiosis. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Mycorrhizas and soil structure.

    Science.gov (United States)

    Rillig, Matthias C; Mummey, Daniel L

    2006-01-01

    In addition to their well-recognized roles in plant nutrition and communities, mycorrhizas can influence the key ecosystem process of soil aggregation. Here we review the contribution of mycorrhizas, mostly focused on arbuscular mycorrhizal fungi (AMF), to soil structure at various hierarchical levels: plant community; individual root; and the soil mycelium. There are a suite of mechanisms by which mycorrhizal fungi can influence soil aggregation at each of these various scales. By extension of these mechanisms to the question of fungal diversity, it is recognized that different species or communities of fungi can promote soil aggregation to different degrees. We argue that soil aggregation should be included in a more complete 'multifunctional' perspective of mycorrhizal ecology, and that in-depth understanding of mycorrhizas/soil process relationships will require analyses emphasizing feedbacks between soil structure and mycorrhizas, rather than a uni-directional approach simply addressing mycorrhizal effects on soils. We finish the discussion by highlighting new tools, developments and foci that will probably be crucial in further understanding mycorrhizal contributions to soil structure.

  1. Micorriza arbuscular e nutrição fosfática na toxidez de zinco para a trema [Trema micrantha (L. Blum.] Arbuscular mycorrhiza and phosphorus nutrition on zinc toxicity to trema [Trema micrantha (L. Blum.

    Directory of Open Access Journals (Sweden)

    Cláudio Roberto Fonsêca Sousa Soares

    2006-08-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de micorriza arbuscular, do estado nutricional de P da planta e de concentrações crescentes de P em solução nutritiva na toxidez de Zn para Trema micrantha (L. Blum. Em um primeiro experimento, mudas de trema foram formadas em substrato que continha doses crescentes de P [0, 100, 200 e 400 mg dm-3 na forma de Ca(H2PO42] e um tratamento de inoculação com Glomus etunicatum (Ge. Após crescimento por 60 dias, as mudas foram transferidas para vasos com solução nutritiva de Clark, que continha 2, 75, 150 e 225 µmol L-1 de Zn, e mantidas por mais 40 dias, quando foram colhidas e avaliadas. Os efeitos do P na amenização da fitotoxidez de Zn foram avaliados em outro experimento, aplicando-se, simultaneamente e de forma combinada em solução, doses de P (0,07; 0,5; 1 e 2 mmol L-1 fornecido por diferentes fontes e de Zn (2, 75, 150 e 225 µmol L-1 na forma de ZnSO4.7H2O, nas quais foram cultivadas mudas de trema por 40 dias. Houve acentuada inibição no crescimento e na colonização micorrízica da trema em doses elevadas de Zn em solução (150 e 225 µmol L-1. Constatou-se que a melhoria da nutrição fosfática reduziu a translocação do Zn das raízes para a parte aérea, mas isto, assim como a colonização micorrízica, não resultou em favorecimento do crescimento da planta em condições de excesso deste metal em solução. No segundo experimento, verificou-se que a elevação na concentração de P em solução nutritiva promoveu melhoria no estado nutricional de P, conferindo proteção à planta do excesso de Zn. Como a especiação química da solução indicou que a aplicação de P não interferiu, de modo significativo, nas formas de Zn em solução, os resultados indicam que a ação amenizante do P ocorre na planta, possivelmente reduzindo a translocação do Zn das raízes para a parte aérea.The objectives of the present study were to evaluate the effects of arbuscular

  2. Colonização por fungos micorrízicos arbusculares e teores de nutrientes em cinco cultivares de bananeiras em um Latossolo da Amazônia Arbuscular mycorrhizae fungi and nutrient contents in five banana cultivars on an Amazonian Oxisol

    Directory of Open Access Journals (Sweden)

    Arlem Nascimento de Oliveira

    2005-06-01

    Full Text Available A bananeira é uma espécie de grande importância sócio-econômica na Amazônia, mas precisa de altos insumos agrícolas para ser produtiva. A associação com fungos micorrízicos arbusculares (FMAs pode minimizar as suas necessidades nutricionais nos solos pobres da Amazônia. O presente trabalho objetivou verificar a ocorrência de associação micorrízica e os teores de nutrientes em bananeiras cultivadas em um Latossolo ácido da Amazônia. O bananal encontra-se deficiente em macro (Ca, Mg e P e micronutrientes (Fe, Mn, Zn e Cu. A colonização micorrízica foi de 54,9 %, no cultivar Mysore; 51,5 %, na Maçã, 47,6 %, na Pacovan; 47,3 %, na Nanica, e 44,7 %, na banana Prata, ocorrendo diferenças significativas. Os cultivares Mysore e Maçã apresentaram maiores índices de colonização radicular nos meses de janeiro e agosto, enquanto a Nanica, nos meses de julho, janeiro e agosto. Os cultivares Pacovan e Prata não apresentaram variações significativas de colonização por FMAs nas épocas estudadas. Nos cultivares, a associação micorrízica correlacionou-se significativamente com os teores de K, Mg, P e Zn no cultivar Maçã, K e P no Nanica e Zn no Prata.The Amazon banana plant is of great socio-economical importance, despite its requirement for high agricultural input in order to obtain good yields. An association with arbuscular mycorrhizae fungi could minimize the crop's nutritional needs in the poor soils of the Amazon. The present study aimed at verifying how the plant-fungus mycorrhizal symbiosis influences nutrient concentration in five varieties of adult banana plants cultivated in an acid Amazon Oxisol under field conditions. The banana plantation was defficient in macro (Ca, Mg and P and micronutrients (Fe, Mn, Zn and Cu. The mycorrhizae colonization varied from 33.6 to 66.5 % of the sampled roots. The average mycorrhizae colonization was 54.9 % in the Mysore, 51.5 % in Maçã, 47.6 % in Pacovan, 47.3 % in Nanica, and

  3. Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.)

    Institute of Scientific and Technical Information of China (English)

    YANG Ruyi; YU Guodong; TANG Jianjan; CHEN Xin

    2008-01-01

    It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants.A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species(Solidago canadensis L.)in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments.Three Pb levels(control,300,and 600 mg/kg soil)were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows.Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae,Glomus versiform,Glomus diaphanum,Glomus geosporum,and Glomus etunicatum).The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants.The results showed that S. canadensis was highly dependent on mvcOrrhizae.The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization(root length colonized,RLC%) but did not affect spore numbers,N(including total N and 15N) and P uptake.The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments.The Pb was mostly sequestered in belowground of plant (root and rhizome).The results suggest that the high efficiency of mycorrhizae on nutrient uptake mightgive S. canadensis a great advantage over native species in Pb polluted softs.

  4. 不同氮磷浓度对AM真菌生长和养分吸收的影响%Effect of arbuscular mycorrhiza on growth and nutrition absorption of sorghum under different nitrogen and phosphorus fertilizer levels

    Institute of Scientific and Technical Information of China (English)

    王晓伟; 左楠楠; 金海如

    2013-01-01

    Arbuscular mycorrhiza ( AM) was innoculated to the host plant ( sorghum) and grown in three compartment pot culture system. With addition of different supply levels of nitrogen and phosphorus fertilizer into the mycelium compartment, the aim of this paper was to investigate the effect of arbuscular mycorrhiza on sorghum growth and nutrition absorption ability. The results showed that the arbuscular mycorrhiza colonization rate reached 70% ; the in-noculation increased the dry matter and chlorophyll content, and significantly increased the total nitrogen and phosphorus contents of sorghum. In the innoculation of sorghum, the nitrogen content was increased significantly with the increasing N levels, while decreased with the increasing P levels. When in the treatment of 4 mmol·L-1 nitrogen and 0. 01 mmol·L-1 phosphorus (N2P1) , the plant total nitrogen content was the highest. The phosphorus content was increased with the increasing N and P levels, when in the treatment of 4 mmol·L-1 nitrogen and 0. 1 mmol·L-1 phosphorus (N2P2) , the plant total phosphorus content was the highest. Wherefore the nutrition absorption of AM fungi was affected by the interaction of nitrogen and phosphorus.%以高粱为宿主植物,三室隔离培养盒为培养容器,研究在菌丝室施加不同浓度的N,P肥料下接种AM真菌对高粱生长和养分吸收的影响.结果显示:接种AM真菌的高梁菌根侵染率达到70%以上;接菌高粱生物量和叶绿素含量均比未接菌时高,且总氮总磷含量均有显著的提高.在接菌情况下,高梁总氮含量随氮浓度的升高而升高,随磷浓度的升高而降低;且在施肥处理为4 mmol·L-1氮肥、0.01 mmol·L-1磷肥(N2P1)情况下高粱总氮含量最高,高梁的总磷含量随氮、磷浓度的升高而升高,并在施肥处理为4 mmol·L-1氮肥、0.1 mmol·L-1磷肥(N2P2)情况下含量达到最高.研究结果表明,AM真菌吸收氮磷营养的能力存在交互作用.

  5. 丛枝菌根对牧草与草地生态系统的重要作用及其研究展望%Research Prospect and the Important Role of Arbuscular Mycorrhizae on Forage Grasses and Grassland Ecosystem

    Institute of Scientific and Technical Information of China (English)

    白梨花; 斯日格格; 曹丽霞; 乌恩

    2013-01-01

    Arbuscular mycorrhizae are important parts of the grassland ecosystem. In this paper, the roles of arbuscular mycorrhizae in nutrient absorption, stress resistance, growth, competition and coexistence of forage grasses, as well as the community structure adjustment, and productivity increase are summarized. Related research of mycorrhizae conducted in our country are prospected, such as: investigating mycorrhi-zal symbiotic and dependent characteristic of main forage grass; the effects of mycorrhizae on forage grass competition; screening highly efficient fungi and applied technology; the comprehensive effects of mycorrhizae on the ecosystem; the influences of mycorrhizae on plant competition; the reciprocity of grassland management and mycorrhizal effects; the function of mycorrhizae on restoring degenerated grassland vegetation; the effects of mycorrhizae on remediation of contaminated soil; the establishment of grassland mycorrhizal resources database in our country.%丛枝菌根是草地生态系统的重要组成部分,其对系统的重要作用日益引起人们的广泛关注.为促进相关研究,本文综述了丛枝菌对牧草养分吸收、抗逆性、生长发育以及对草地生态系统中牧草间竞争与共存、群落结构调节、提高草地生产力等的重要作用.针对我国当前相关的研究:即主要牧草进行菌根共生特性与菌根依赖性的调查研究、菌根对牧草竞争的影响研究、高效菌种筛选与接种应用技术的开发研究、对草地生态系统进行丛枝菌根综合效应的研究、菌根对牧草竞争的影响研究、草地管理与菌根效应相互关系的研究、丛枝菌根对退化草地植被恢复的作用研究、污染草地土壤菌根修复的研究、草地丛枝菌根资源库的建立等进行了展望.

  6. Consequences of pre-inoculation with native arbuscular mycorrhizae on root colonization and survival of Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) seedlings after transplanting

    Science.gov (United States)

    Bill Eugene Davidson

    2015-01-01

    Inoculation of seedlings with arbuscular mycorrhizal fungi (AMF) is a common practice aimed at improving seedling establishment. The success of this practice largely depends on the ability of the inoculum to multiply and colonize the growing root system after transplanting. These events were investigated in Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush...

  7. Effect of mycorrhizas application on plant growth and nutrient uptake in cucumber production under field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ortas, I.

    2010-07-01

    Mycorrhizas application in horticultural production in the Eastern Mediterranean region of Turkey has been studied under field conditions for several years. The effects of different arbuscular mycorrhizal fungi (AMF) have been evaluated under field conditions for cucumber production. The parameters measured were seedling survival, plant growth and yield, and root colonization. In 1998 and 1999, Glomus mosseae and Glomus etunicatum inoculated cucumber seedlings were treated with and without P (100 kg P2O5 ha-1) application. A second experiment was set up to evaluate the response of cucumber to the inoculation with a consortia of indigenous mycorrhizae, G. mosseae, G. etunicatum, Glomus clarum, Glomus caledonium and a mixture of these four species. Inoculated and control non inoculated cucumber seedlings were established under field conditions in 1998, 2001, 2002 and 2004. Seedling quality, seedling survival under field conditions and yield response to mycorrhiza were tested. Fruits were harvested periodically; at blossom, plant leaves and root samples were taken for nutrient content and mycorrhizal colonization analysis respectively. The field experiment results showed that mycorrhiza inoculation significantly increased cucumber seedling survival, fruit yield, P and Zn shoot concentrations. Indigenous mycorrhiza inoculum was successful in colonizing plant roots and resulted in better plant growth and yield. The relative effectiveness of each of the inocula tested was not consistent in the different experiments, although inoculated plants always grew better than control no inoculated. The most relevant result for growers was the increased survival of seedlings. (Author) 20 refs.

  8. Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions.

    Science.gov (United States)

    Bowles, Timothy M; Barrios-Masias, Felipe H; Carlisle, Eli A; Cavagnaro, Timothy R; Jackson, Louise E

    2016-10-01

    Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future.

  9. Influencia de la fertilización, la época y la especie forrajera en la presencia Influence of fertilization, season, and forage species in presence of arbuscular mycorrhizae in a degraded Andisoil of Colombia

    Directory of Open Access Journals (Sweden)

    Arnulfo Gómez-Carabalí

    2011-01-01

    and percentage of root infection of arbuscular mycorrhiza increased with age and varied with the species and season. We founded differences among forage grass and legume species under field conditions to form symbiosis with mycorrhizal fungi. Knowledge on these interspecific differences could contribute to developing better adapted forage systems to contribute recuperating the degraded soils of the Andean hillsides of Latin America.

  10. Chromium resistance of dandelion (Taraxacum platypecidum Diels.) and bermudagrass (Cynodon dactylon [Linn.] Pers.) is enhanced by arbuscular mycorrhiza in Cr(VI)-contaminated soils.

    Science.gov (United States)

    Wu, Song-Lin; Chen, Bao-Dong; Sun, Yu-Qing; Ren, Bai-Hui; Zhang, Xin; Wang, You-Shan

    2014-09-01

    In a greenhouse pot experiment, dandelion (Taraxacum platypecidum Diels.) and bermudagrass (Cynodon dactylon[Linn.] Pers.), inoculated with and without arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis, were grown in chromium (Cr)-amended soils (0 mg/kg, 5 mg/kg, 10 mg/kg, and 20 mg/kg Cr[VI]) to test whether arbuscular mycorrhizal (AM) symbiosis can improve Cr tolerance in different plant species. The experimental results indicated that the dry weights of both plant species were dramatically increased by AM symbiosis. Mycorrhizal colonization increased plant P concentrations and decreased Cr concentrations and Cr translocation from roots to shoots for dandelion; in contrast, mycorrhizal colonization decreased plant Cr concentrations without improvement of P nutrition in bermudagrass. Chromium speciation analysis revealed that AM symbiosis potentially altered Cr species and bioavailability in the rhizosphere. The study confirmed the protective effects of AMF on host plants under Cr contaminations. © 2014 SETAC.

  11. Improvement of Arbuscular Mycorrhiza Development by Inoculation of Soil with Phosphate-Solubilizing Rhizobacteria To Improve Rock Phosphate Bioavailability ((sup32)P) and Nutrient Cycling

    OpenAIRE

    Toro, M.; Azcon, R.; Barea, J.

    1997-01-01

    The interactive effect of phosphate-solubilizing bacteria and arbuscular mycorrhizal (AM) fungi on plant use of soil P sources of low bioavailability (endogenous or added as rock phosphate [RP] material) was evaluated by using soil microcosms which integrated (sup32)P isotopic dilution techniques. The microbial inocula consisted of the AM fungus Glomus intraradices and two phosphate-solubilizing rhizobacterial isolates: Enterobacter sp. and Bacillus subtilis. These rhizobacteria behaved as "m...

  12. Rice arbuscular mycorrhiza as a tool to study the molecular mechanisms of fungal symbiosis and a potential target to increase productivity.

    Science.gov (United States)

    Nakagawa, Tomomi; Imaizumi-Anraku, Haruko

    2015-12-01

    Rice (Oryza sativa L.) is a monocot model crop for cereal molecular biology. Following the emergence of molecular genetics of arbuscular mycorrhizal (AM) symbiosis in model legumes in the 1990s, studies on rice genetic resources have considerably contributed to our understanding of the molecular mechanisms and evolution of root intracellular symbioses.In this review, we trace the history of these studies and suggest the potential utility of AM symbiosis for improvement in rice productivity.

  13. Study on Arbuscular Mycorrhiza Fungi Diversity and Inoculation Effect of Prunus mongolica%蒙古扁桃AMF多样性及其AMF接种效应研究

    Institute of Scientific and Technical Information of China (English)

    王琚钢; 白淑兰; 盖京苹; 慈忠玲; 方亮

    2011-01-01

    Mycorrhizal status of Prunus mongolica of western Inner Mongolia in the desert region was studied by observing the ectomycorrhiza morphological and the arbuscular mycrrhizal structure of the nutritive root.Ectomycorrhiza colonization was not found in the present study, while arbuscular mycrrhiza colonized quite well, and the highest frequency of colonization was 97%. Eleven arbuscular mycorrhizal fungi species of four genera and one uncertain species were identified by the morphologiacal identification of the spores, among which Acaulosopra rehmii and Glomus mosseae were the dominant species. In addition, Glomus mosseae and Glomous versiforme were inoculated on Prunus mongolica, and the result showed that the nutritive root of Prunus mongolica and the Glomus mosseae could form the typical arbuscular mycrrhizal structure as hyphae,vesicles and arbuscular, but not with the Glomous versiforme. Glomus mosseae promoted the growth of Prunus mongolica.%以内蒙古西部沙漠地区蒙古扁(Prunus mongokica)为对象,对野外采集的蒙古扁桃营养根进行外生菌根形态观察及采用Phillips & Hayman染色方法观察根内丛枝菌根结构,同时通过形态学方法对根际孢子进行鉴定.结果表明:所采样品未发现外生菌根侵染,而丛枝菌根的侵染频度高达97%以上.在根际土中共鉴定出丛枝菌根真菌4属11种,和1个未知种,其中瑞氏无梗囊霉和摩西球囊霉是蒙古扁桃根际土中的优势种.另外,在实验室条件下,用摩西球囊霉和地表球囊霉对蒙古扁桃进行人工接种试验,结果表明:摩西球囊霉接种处理下,蒙古扁桃营养根细胞内形成菌丝、丛枝、泡囊等典型的丛枝菌根结构,而地表球囊霉接种处理在蒙古扁桃营养根内未形成丛枝菌根结构;摩西球囊霉在形成丛枝菌根后明显促进了蒙古扁桃的生长.

  14. Arbuscular mycorrhiza enhanced arsenic resistance of both white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.) plants in an arsenic-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Dong Yan; Zhu Yongguan [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Smith, F. Andrew [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, Adelaide, SA 5005 (Australia); Wang Youshan [Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry, Beijing 100089 (China); Chen Baodong [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)], E-mail: bdchen@rcees.ac.cn

    2008-09-15

    In a compartmented cultivation system, white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.), with their roots freely intermingled, or separated by 37 {mu}m nylon mesh or plastic board, were grown together in an arsenic (As) contaminated soil. The influence of AM inoculation on plant growth, As uptake, phosphorus (P) nutrition, and plant competitions were investigated. Results showed that both plant species highly depended on mycorrhizas for surviving the As contamination. Mycorrhizal inoculation substantially improved plant P nutrition, and in contrast markedly decreased root to shoot As translocation and shoot As concentrations. It also showed that mycorrhizas affected the competition between the two co-existing plant species, preferentially benefiting the clover plants in term of nutrient acquisition and biomass production. Based on the present study, the role of AM fungi in plant adaptation to As contamination, and their potential use for ecological restoration of As contaminated soils are discussed. - Both white clover and ryegrass highly depend on the mycorrhizal associations for surviving heavy arsenic contamination.

  15. EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGI ON THE DEVELOPMENT OF TWO LEGUMINOUS TREES

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius Winckler Caldeira

    2009-09-01

    Full Text Available In a green house at the National Center of Research of Agrobiology (CNPAB/EMBRAPA, the effect of the inoculation of Arbuscular Micorrhizal Fungi (AMF in the production of Peltogyne venosa and Sclerolobium paniculatum was evaluated. The experimental design was completely randomized with 4 treatments (Glomus clarum Nicolson & Schenk, Gigaspora margarita Becke Hall, native mycorrhizae and controls - without inoculation and 25 repetitions. One hundred sixty eight days after seed germination, it was observed that the treatments did not affect seedling growth, except for P. venosa inoculated with G. margarita, which had a larger production of dry weight of fine roots. Seedlings of P. venosa and S. paniculatum inoculated with G. clarum and native mycorrhizae had the largest percentages of micorrhizal colonization. In both species studied, the largest survival percentages was of seedlings inoculated with native mycorrhizae.

  16. 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.

  17. Quantitative and Qualitative Effects of Phosphorus on Extracts and Exudates of Sudangrass Roots in Relation to Vesicular-Arbuscular Mycorrhiza Formation

    Science.gov (United States)

    Schwab, Suzanne M.; Menge, John A.; Leonard, Robert T.

    1983-01-01

    A comparison was made of water-soluble root exudates and extracts of Sorghum vulgare Pers. grown under two levels of P nutrition. An increase in P nutrition significantly decreased the concentration of carbohydrates, carboxylic acids, and amino acids in exudates, and decreased the concentration of carboxylic acids in extracts. Higher P did not affect the relative proportions of specific carboxylic acids and had little effect on proportions of specific amino acids in both extracts and exudates. Phosphorus amendment resulted in an increase in the relative proportion of arabinose and a decrease in the proportion of fructose in exudates, but did not have a large effect on the proportion of individual sugars in extracts. The proportions of specific carbohydrates, carboxylic acids, and amino acids varied between exudates and extracts. Therefore, the quantity and composition of root extracts may not be a reliable predictor of the availability of substrate for symbiotic vesicular-arbuscular mycorrhizal fungi. Comparisons of the rate of leakage of compounds from roots with the growth rate of vesicular-arbuscular mycorrhizal fungi suggest that the fungus must either be capable of using a variety of organic substrates for growth, or be capable of inducing a much higher rate of movement of specific organic compounds across root cell membranes than occurs through passive exudation as measured in this study. PMID:16663297

  18. Influence of bacterial strains isolated from lead-polluted soil and their interactions with arbuscular mycorrhizae on the growth of Trifolium pratense L. under lead toxicity.

    Science.gov (United States)

    Vivas, A; Azcón, R; Biró, B; Barea, J M; Ruiz-Lozano, J M

    2003-10-01

    We isolated two bacterial strains from an experimentally lead (Pb)-polluted soil in Hungary, 10 years after soil contamination. These strains represented the two most abundant cultivable bacterial groups in such soil, and we tested their influence on Trifolium pratense L. growth and on the functioning of native mycorrhizal fungi under Pb toxicity in a second Pb-spiked soil. Our results showed that bacterial strain A enhanced plant growth, nitrogen and phosphorus accumulations, nodule formation, and mycorrhizal infection, demonstrating its plant-growth-promoting activity. In addition, strain A decreased the amount of Pb absorbed by plants, when expressed on a root weight basis, because of increased root biomass due to the production of indoleacetic acid. The positive effect of strain A was not only evident after a single inoculation but also in dual inoculation with arbuscular mycorrhizal fungi. Strain A also exhibited higher tolerance than strain B when cultivated under increasing Pb levels in the spiked soil. Molecular identification unambiguously placed strain A within the genus Brevibacillus. We showed that it is important to select the most tolerant and efficient bacterial strain for co-inoculation with arbuscular mycorrhizal fungi to promote effective symbiosis and thus stimulate plant growth under adverse environmental conditions, such as heavy-metal contamination.

  19. Micorriza arbuscular em plantações de Eucalyptus cloeziana F. Muell no litoral norte da Bahia, Brasil Arbuscular mycorrhiza in Eucalyptus cloeziana F. Muell plantations in the north littoral of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Cristiano V.M. Araújo

    2004-09-01

    Full Text Available As micorrizas arbusculares são de longa data conhecidas e exploradas devido à importância ecológica e aos efeitos no crescimento e na nutrição das plantas. Eucalyptus cloeziana F. Muell, particularmente nas áreas em estudo, apresenta comportamento diferenciado quando comparado com outras espécies de eucaliptos, instalando-se em sítios de solos pobres e textura arenosa, com crescimento reduzido, dificuldades para a formação das mudas e problemas nutricionais. Objetivando avaliar a percentagem de colonização radicular e a densidade de esporos de fungos micorrízicos arbusculares em plantações de E. cloeziana, foram realizadas coletas de solo rizosférico e de raízes em 20 áreas, distribuídas em seis municípios do Estado da Bahia, Brasil. Os resultados médios da percentagem de colonização variaram de 10% a 96,66% e a densidade de esporos variou de 3 a 110 esporos/50cm³ de solo, demonstrando a grande suscetibilidade do E. cloeziana à micorrização.The arbuscular mycorrhizal are known and explored long ago due to the ecological significance and the effects in the growth and nutrition of the plants. Eucalyptus cloeziana F. Muell, particularly in the studied sites, exhibit differenced behaviour when compared with other eucaliptus species, establishing in sites of the poor soils and sandy texture, with reduced growth, difficulty to formation of the seedling and nutritional problems. Aiming to evaluate the percentage of mycorrhizal colonization, as well as the density of arbuscular mycorrhizal fungi spores in E. cloeziana plantations, rhizospheric soil and roots samples were collected in twenty sites, distributed in six municipalities of Bahia state, Brazil. The mean results of percentage root colonization ranged from 10 to 96.66% and spore number ranged from 3 to 110 spores/50cm³ soil, demonstrating high susceptibility of the E. cloeziana to mycorrhization.

  20. 大针茅根际AM真菌的分子鉴定及不同放牧强度对AM侵染的影响%Identification of Arbuscular mycorrhiza Fungi of Stipa grandis and Infecting Effects under Grazing Intensity

    Institute of Scientific and Technical Information of China (English)

    曹路; 索培芬; 韩冰; 赵萌莉; 海丽丽

    2015-01-01

    大针茅(Stipa grandis P.Smirn.)是我国北方典型草原上的建群种或优势种植物,具有重要的饲用价值.大针茅根系能够形成丛枝菌根(arbuscular mycorrhiza,AM).采集围栏区的大针茅根系,根据18S rDNA序列鉴定大针茅根系中的AM真菌为球囊霉属(Glomus)的根内球囊霉(G.intraradices).通过对轻度放牧区、中度放牧区、重度放牧区和未放牧的对照区(30年围栏草场)大针茅根系AM真菌侵染情况的分析,发现不同放牧强度下菌丝侵染率和总侵染率都不存在显著性差异.放牧利用总体降低了丛枝的侵染率.放牧强度影响AM真菌泡囊结构在大针茅根系中的发育,轻度和中度放牧促进AM真菌泡囊的形成,而重度放牧则显著抑制.放牧强度对大针茅AM真菌的影响主要体现在AM真菌营养的交换和繁殖方面,AM真菌光合产物的减少属于中性反应,对碳的需求相对较少,这可能也是大针茅具有较强耐牧性的原因之一.

  1. Interactive effects of silicon and arbuscular mycorrhiza in modulating ascorbate-glutathione cycle and antioxidant scavenging capacity in differentially salt-tolerant Cicer arietinum L. genotypes subjected to long-term salinity.

    Science.gov (United States)

    Garg, Neera; Bhandari, Purnima

    2016-09-01

    Salinity is the major environmental constraint that affects legume productivity by inducing oxidative stress. Individually, both silicon (Si) nutrition and mycorrhization have been reported to alleviate salt stress. However, the mechanisms adopted by both in mediating stress responses are poorly understood. Thus, pot trials were undertaken to evaluate comparative as well as interactive effects of Si and/or arbuscular mycorrhiza (AM) in alleviating NaCl toxicity in modulating oxidative stress and antioxidant defence mechanisms in two Cicer arietinum L. (chickpea) genotypes-HC 3 (salt-tolerant) and CSG 9505 (salt-sensitive). Plants subjected to different NaCl concentrations (0-100 mM) recorded a substantial increase in the rate of superoxide radical (O2 (·-)), H2O2, lipoxygenase (LOX) activity and malondialdehyde (MDA) content, which induced leakage of ions and disturbed Ca(2+)/Na(+) ratio in roots and leaves. Individually, Si and AM reduced oxidative burst by strengthening antioxidant enzymatic activities (superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPOX)). Si was relatively more efficient in reducing accumulation of stress metabolites, while mycorrhization significantly up-regulated antioxidant machinery and modulated ascorbate-glutathione (ASA-GSH) cycle. Combined applications of Si and AM complemented each other in reducing reactive oxygen species (ROS) build-up by further enhancing the antioxidant defence responses. Magnitude of ROS-mediated oxidative burden was lower in HC 3 which correlated strongly with more effective AM symbiosis, better capacity to accumulate Si and stronger defence response when compared with CSG 9505. Study indicated that Si and/or AM fungal amendments upgraded salt tolerance through a dynamic shift from oxidative destruction towards favourable antioxidant defence system in stressed chickpea plants.

  2. Management of disease complex caused by root knot nematode and root wilt fungus on pigeonpea through soil organically enriched with Vesicular Arbuscular Mycorrhiza, karanj (Pongamia pinnata) oilseed cake and farmyard manure.

    Science.gov (United States)

    Goswami, B K; Pandey, Rajesh Kumar; Goswami, Jaideep; Tewari, D D

    2007-11-01

    This investigation was undertaken to compare the percentage response of colonization and development of VA-Mycorrhiza (Glomus fasciculatum) on a number of pulse crops viz. cowpea, chickpea, soybean, pigeonpea and lentil under glasshouse conditions. Among the above-mentioned crops, pigeonpea exhibited the best performance and was selected for further studies. In this host the development and colonization percentage of G. fasciculatum was investigated under two separate substrates i. e. soil amended with FYM and karanj oilseed cake keeping a control treatment of field soil. A third treatment amended with karanj oilseed cake and farm yard manure (FYM) was also kept which responded best in terms of colonization percentage. This treatment showing improved plant health as well as integration with G. fasciculatum was selected as an ideal treatment for the management of disease complex caused by root knot nematode, Meloidogyne incognita and root wilt fungus, Fusarium udum on pigeonpea. Thus the treatment constituting FYM, karanj oilseed cake and VA-Mycorrhiza reduced the disease incidence caused by both maladies to a great extent with the most promising improvement in plant growth parameters as compared to all others. The present investigation, in addition to proposing an ideal eco-friendly treatment for the management of this disease complex also proposed an excellent medium for the proliferation of the obligate bio-protectant, G. fasciculatum.

  3. Use of Arbuscular Mycorrhiza and Organic Amendments to Enhance Growth of Macaranga peltata (Roxb.) Müll. Arg. in Iron Ore Mine Wastelands.

    Science.gov (United States)

    Rodrigues, Cassie R; Rodrigues, Bernard F

    2015-01-01

    Macaranga peltata (Roxb.) Mull. Arg. is a disturbance tolerant plant species with potential in mine wasteland reclamation. Our study aims at studying the phyto-extraction potential of M. peltata and determining plant-soil interaction factors effecting plant growth in iron ore mine spoils. Plants were grown in pure mine spoil and spoil amended with Farm Yard Manure (FYM) and Vermicompost (VC) along with arbuscular mycorrhizal (AM) species Rhizophagus irregularis. Pure and amended mine spoils were evaluated for nutrient status. Plant growth parameters and foliar nutrient contents were determined at the end of one year. FYM amendment in spoil significantly increased plant biomass compared to pure mine spoil and VC amended spoil. Foliar Fe accumulation was recorded highest (594.67 μg/g) in pure spoil with no mortality but considerably affecting plant growth, thus proving to exhibit phyto-extraction potential. FYM and VC amendments reduced AM colonization (30.4% and 37% resp.) and plants showed a negative mycorrhizal dependency (-30.35 and -39.83 resp.). Soil pH and P levels and, foliar Fe accumulation are major factors determining plant growth in spoil. FYM amendment was found to be superior to VC as a spoil amendment for hastening plant growth and establishment in iron ore mine spoil.

  4. Do jasmonates play a role in arbuscular mycorrhiza-induced local bioprotection of Medicago truncatula against root rot disease caused by Aphanomyces euteiches?

    Science.gov (United States)

    Hilou, Adama; Zhang, Haoqiang; Franken, Philipp; Hause, Bettina

    2014-01-01

    Bioprotective effects of mycorrhization with two different arbuscular mycorrhizal (AM) fungi, Funneliformis mosseae and Rhizophagus irregularis, against Aphanomyces euteiches, the causal agent of root rot in legumes, were studied in Medicago truncatula using phenotypic and molecular markers. Previous inoculation with an AM-fungus reduced disease symptoms as well as the amount of pathogen within roots, as determined by the levels of A. euteiches rRNA or transcripts of the gene sterol C24 reductase. Inoculation with R. irregularis was as efficient as that with F. mosseae. To study whether jasmonates play a regulatory role in bioprotection of M. truncatula by the AM fungi, composite plants harboring transgenic roots were used to modulate the expression level of the gene encoding M. truncatula allene oxide cyclase 1, a key enzyme in jasmonic acid biosynthesis. Neither an increase nor a reduction in allene oxide cyclase levels resulted in altered bioprotection by the AM fungi against root infection by A. euteiches. These data suggest that jasmonates do not play a major role in the local bioprotective effect of AM fungi against the pathogen A. euteiches in M. truncatula roots.

  5. Effect of P Availability on Temporal Dynamics of Carbon Allocation and Glomus intraradices High-Affinity P Transporter Gene Induction in Arbuscular Mycorrhiza

    Science.gov (United States)

    Olsson, Pål Axel; Hansson, Maria C.; Burleigh, Stephen H.

    2006-01-01

    Arbuscular mycorrhizal (AM) fungi depend on a C supply from the plant host and simultaneously provide phosphorus to the colonized plant. We therefore evaluated the influence of external P on C allocation in monoxenic Daucus carota-Glomus intraradices cultures in an AM symbiosis. Fungal hyphae proliferated from a solid minimal medium containing colonized roots into a C-free liquid minimal medium with high or low P availability. Roots and hyphae were harvested periodically, and the flow of C from roots to fungus was measured by isotope labeling. We also measured induction of a G. intraradices high-affinity P transporter to estimate fungal P demand. The prevailing hypothesis is that high P availability reduces mycorrhizal fungal growth, but we found that C flow to the fungus was initially highest at the high P level. Only at later harvests, after 100 days of in vitro culture, were C flow and fungal growth limited at high P availability. Thus, AM fungi can benefit initially from P-enriched environments in terms of plant C allocation. As expected, the P transporter induction was significantly greater at low P availability and greatest in very young mycelia. We found no direct link between C flow to the fungus and the P transporter transcription level, which indicates that a good C supply is not essential for induction of the high-affinity P transporter. We describe a mechanism by which P regulates symbiotic C allocation, and we discuss how this mechanism may have evolved in a competitive environment. PMID:16751522

  6. Genetic Exchange in an Arbuscular Mycorrhizal Fungus Results in Increased Rice Growth and Altered Mycorrhiza-Specific Gene Transcription▿†

    Science.gov (United States)

    Colard, Alexandre; Angelard, Caroline; Sanders, Ian R.

    2011-01-01

    Arbuscular mycorrhizal fungi (AMF) are obligate symbionts with most terrestrial plants. They improve plant nutrition, particularly phosphate acquisition, and thus are able to improve plant growth. In exchange, the fungi obtain photosynthetically fixed carbon. AMF are coenocytic, meaning that many nuclei coexist in a common cytoplasm. Genetic exchange recently has been demonstrated in the AMF Glomus intraradices, allowing nuclei of different Glomus intraradices strains to mix. Such genetic exchange was shown previously to have negative effects on plant growth and to alter fungal colonization. However, no attempt was made to detect whether genetic exchange in AMF can alter plant gene expression and if this effect was time dependent. Here, we show that genetic exchange in AMF also can be beneficial for rice growth, and that symbiosis-specific gene transcription is altered by genetic exchange. Moreover, our results show that genetic exchange can change the dynamics of the colonization of the fungus in the plant. Our results demonstrate that the simple manipulation of the genetics of AMF can have important consequences for their symbiotic effects on plants such as rice, which is considered the most important crop in the world. Exploiting natural AMF genetic variation by generating novel AMF genotypes through genetic exchange is a potentially useful tool in the development of AMF inocula that are more beneficial for crop growth. PMID:21784911

  7. Integration of crop rotation and arbuscular mycorrhiza (AM) inoculum application for enhancing AM activity to improve phosphorus nutrition and yield of upland rice (Oryza sativa L.).

    Science.gov (United States)

    Maiti, Dipankar; Toppo, Neha Nancy; Variar, Mukund

    2011-11-01

    Upland rice (Oryza sativa L.) is a major crop of Eastern India grown during the wet season (June/July to September/October). Aerobic soils of the upland rice system, which are acidic and inherently phosphorus (P) limiting, support native arbuscular mycorrhizal (AM) activity. Attempts were made to improve P nutrition of upland rice by exploiting this natural situation through different crop rotations and application of AM fungal (AMF) inoculum. The effect of a 2-year crop rotation of maize (Zea mays L.) followed by horse gram (Dolichos biflorus L.) in the first year and upland rice in the second year on native AM activity was compared to three existing systems, with and without application of a soil-root-based inoculum. Integration of AM fungal inoculation with the maize-horse gram rotation had synergistic/additive effects in terms of AMF colonization (+22.7 to +42.7%), plant P acquisition (+11.2 to +23.7%), and grain yield of rice variety Vandana (+25.7 to +34.3%).

  8. 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.

  9. El tiempo de establecimiento de postura y su relación con la micorriza arbuscular en paisajes de loma y vega Time of Stablishment of Pastures and Their Relationship with Arbuscular Mycorrhiza in Hilly Terrain and Fertile Valley

    Directory of Open Access Journals (Sweden)

    Posada Almanza Raúl Hernando

    2006-12-01

    Full Text Available El presente trabajo fue realizado para evaluar el efecto del tiempo (0-5 años, 5-10 años y más de 10 años de establecimiento de pasturas de Brachiaria sp. sobre las poblaciones de hongos de micorriza arbuscular (HMA, su distribución de esporas, géneros, longitud de micelio extramatrical, colonización radical por HMA y otros hongos, en sistemas donde previamente existían bosques, en paisajes de loma y vega en Florencia, Caquetá, Colombia. Cualquiera que sea la edad de establecimiento de la pastura, predominan los géneros Glomus y Acaulospora; el cambio de la cobertura requiere de un periodo de más de diez años para que diferentes especies de HMA puedan recolonizar, adaptarse y diversificarse. En loma, la relación de Brachiaria sp. con los HMA disminuye con la edad, especialmente después de diez años; en vega se mantiene media y estable (21-50 %, mientras la colonización radical por hongos diferentes a los HMA se incrementa, mostrando posiblemente un mecanismo de competencia por el espacio radical, o una acción conjunta. Finalmente, el micelio extramatrical y las esporas en loma y vega siguen tendencias variables (incremento, descenso o
    estabilidad con la edad.The subject of this research was to evaluate the effect of the time of establishment (0-5 years, 5-10 years, and more than 10 years. of pastures of Brachiaria sp. over theArbuscular Mycorrhizal Fungal populations (AMF: genus and spore distribution, length of extramatrical mycelia, root colonizations by AMF and septate fungi; the pastures resulting from fragmentation of the tropical rainforest with valley and hilly landscapes at Florencia, Caquetá, Colombia. Whichever the age of pasture, the genera Glomus and Acaulospora predominate; the change of coverage require more than ten years for different species of MAF to recolonize, adapt and diversify. In hilly terrain, the Brachiaria sp-MAF relationship decrease with time, specially after ten years of establishment; in

  10. EL TIEMPO DE ESTABLECIMIENTO DE PASTURAS Y SU RELACIÓN CON LA MICORRIZA ARBUSCULAR EN PAISAJES DE LOMA Y VEGA Time of Stablishment of Pastures and Their Relationship with Arbuscular Mycorrhiza in Hilly Terrain and Fertile Valley

    Directory of Open Access Journals (Sweden)

    RAÚL HERNANDO POSADA ALMANZA

    Full Text Available El presente trabajo fue realizado para evaluar el efecto del tiempo (05 años, 510 años y más de 10 años de establecimiento de pasturas de Brachiaria sp. sobre las poblaciones de hongos de micorriza arbuscular (HMA, su distribución de esporas, géneros, longitud de micelio extramatrical, colonización radical por HMA y otros hongos, en sistemas donde previamente existían bosques, en paisajes de loma y vega en Florencia, Caquetá, Colombia. Cualquiera que sea la edad de establecimiento de la pastura, predominan los géneros Glomus y Acaulospora; el cambio de la cobertura requiere de un periodo de más de diez años para que diferentes especies de HMA puedan recolonizar, adaptarse y diversificarse. En loma, la relación de Brachiaria sp. con los HMA disminuye con la edad, especialmente después de diez años; en vega se mantiene media y estable (2150 %, mientras la colonización radical por hongos diferentes a los HMA se incrementa, mostrando posiblemente un mecanismo de competencia por el espacio radical, o una acción conjunta. Finalmente, el micelio extramatrical y las esporas en loma y vega siguen tendencias variables (incremento, descenso o estabilidad con la edad.The subject of this research was to evaluate the effect of the time of establishment (05 years, 510 years, and more than 10 years. of pastures of Brachiaria sp. over the Arbuscular Mycorrhizal Fungal populations (AMF: genus and spore distribution, length of extramatrical mycelia, root colonizations by AMF and septate fungi; the pastures resulting from fragmentation of the tropical rainforest with valley and hilly landscapes at Florencia, Caquetá, Colombia. Whichever the age of pasture, the genera Glomus and Acaulospora predominate; the change of coverage require more than ten years for different species of MAF to recolonize, adapt and diversify. In hilly terrain, the Brachiaria spMAF relationship decrease with time, specially after ten years of establishment; in valley

  11. Fungos micorrízicos arbusculares em seringueira em latossolo amarelo distrófico da amazônia ocidental Arbuscular mycorrhizae fungi, growth and nutrient content in rubber plants in a xanthic ferrasol of western amazon

    Directory of Open Access Journals (Sweden)

    Larissa Alexandra Cardoso Moraes

    2010-06-01

    Full Text Available A colonização radicular com fungos micorrízicos arbusculares (FMA pode aumentar a eficiência no crescimento e absorção de nutrientes pelas plantas. Com o objetivo de verificar esse efeito, foram avaliados o grau de colonização em seringais adultos cultivados em Latossolo Amarelo distrófico e a eficiência de seis FMAs na colonização, crescimento e estado nutricional de mudas de seringueira com três e seis meses de transplantio. Os resultados indicaram baixo grau de colonização micorrízica e número de esporos em seringal adulto. Seis meses depois do transplantio das mudas de seringueira foram suficientes para ocorrer colonização de FMAs detectável. Não houve aumento no incremento em altura, diâmetro e emissão de folhas, independentemente do inóculo utilizado. Os teores foliares de nutrientes (N, P, K, Ca, Mg, Cu, Fe, Mn e Zn também não foram influenciados pelo número de esporos e grau de colonização, havendo diferenças apenas em função da idade das plantas.The infection roots with arbuscular mycorrhizal fungi (AMF can increase the efficiency in growth and nutrients uptake of plants. With the objective to verify this effect, the degree of colonization in rubber tree plantation cultivated in a Xanthic Ferralsol (dystrophic Yellow Latosol and the efficiency of six AMF in colonization, growth and nutritional status of rubber tree seedlings were evaluated, with three and six months of transplanting. The results showed a low level of mycorrhizal infection and number of spores in adult rubber tree. Six months of transplanting of rubber tree seedlings were sufficient detectable AMFs infection. There was no increase in height, diameter and number of leaves. The foliar nutrients concentration (N, P, K, Ca, Mg, Cu, Fe, Mn and Zn were also not influenced by the number of spores and infection degree, with only differences by age of the plants (three and six months of transplanting.

  12. A set of fluorescent protein-based markers expressed from constitutive and arbuscular mycorrhiza-inducible promoters to label organelles, membranes and cytoskeletal elements in Medicago truncatula.

    Science.gov (United States)

    Ivanov, Sergey; Harrison, Maria J

    2014-12-01

    Medicago truncatula is widely used for analyses of arbuscular mycorrhizal (AM) symbiosis and nodulation. To complement the genetic and genomic resources that exist for this species, we generated fluorescent protein fusions that label the nucleus, endoplasmic reticulum, Golgi apparatus, trans-Golgi network, plasma membrane, apoplast, late endosome/multivesicular bodies (MVB), transitory late endosome/ tonoplast, tonoplast, plastids, mitochondria, peroxisomes, autophagosomes, plasmodesmata, actin, microtubules, periarbuscular membrane (PAM) and periarbuscular apoplastic space (PAS) and expressed them from the constitutive AtUBQ10 promoter and the AM symbiosis-specific MtBCP1 promoter. All marker constructs showed the expected expression patterns and sub-cellular locations in M. truncatula root cells. As a demonstration of their utility, we used several markers to investigate AM symbiosis where root cells undergo major cellular alterations to accommodate their fungal endosymbiont. We demonstrate that changes in the position and size of the nuclei occur prior to hyphal entry into the cortical cells and do not require DELLA signaling. Changes in the cytoskeleton, tonoplast and plastids also occur in the colonized cells and in contrast to previous studies, we show that stromulated plastids are abundant in cells with developing and mature arbuscules, while lens-shaped plastids occur in cells with degenerating arbuscules. Arbuscule development and secretion of the PAM creates a periarbuscular apoplastic compartment which has been assumed to be continuous with apoplast of the cell. However, fluorescent markers secreted to the periarbuscular apoplast challenge this assumption. This marker resource will facilitate cell biology studies of AM symbiosis, as well as other aspects of legume biology. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  13. Arbuscular mycorrhiza mediates glomalin-related soil protein production and soil enzyme activities in the rhizosphere of trifoliate orange grown under different P levels.

    Science.gov (United States)

    Wu, Qiang-Sheng; Li, Yan; Zou, Ying-Ning; He, Xin-Hua

    2015-02-01

    Glomalin-related soil protein (GRSP) is beneficial to soil and plants and is affected by various factors. To address whether mycorrhizal-induced GRSP and relevant soil enzymes depend on external P levels, a pot study evaluated effects of the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae on GRSP production and soil enzyme activities. Three GRSP categories, as easily-extractable GRSP (EE-GRSP), difficultly-extractable GRSP (DE-GRSP), and total (EE-GRSP + DE-GRSP) GRSP (T-GRSP), were analyzed, together with five enzyme activities (β-glucosidase, catalase, peroxidase, phosphatase, polyphenol oxidase) in the rhizosphere of trifoliate orange (Poncirus trifoliata) grown under 0, 3, and 30 mM KH2PO4 in a sand substrate. After 4 months, root AM colonization and substrate hyphal length decreased with increasing P levels. Shoot, root, and total biomass production was significantly increased by AM colonization, regardless of P levels, but more profound under 0 mM P than under 30 mM KH2PO4. In general, production of these three GRSP categories under 0 or 30 mM KH2PO4 was similar in non-mycorrhizosphere but decreased in mycorrhizosphere. Mycorrhization significantly increased the production of EE-GRSP, DE-GRSP and T-GRSP, soil organic carbon (SOC), and activity of substrate β-glucosidase, catalase, peroxidase, and phosphatase, but decreased polyphenol oxidase activity, irrespective of P levels. Production of EE-GRSP, DE-GRSP, and T-GRSP significantly positively correlated with SOC and β-glucosidase, catalase, and peroxidase activity, negatively with polyphenol oxidase activity, but not with hyphal length or phosphatase activity. These results indicate that AM-mediated production of GRSP and relevant soil enzyme activities may not depend on external P concentrations.

  14. The interaction of heavy metals and nutrients present in soil and native plants with arbuscular mycorrhizae on the riverside in the Matanza-Riachuelo River Basin (Argentina).

    Science.gov (United States)

    Mendoza, Rodolfo E; García, Ileana V; de Cabo, Laura; Weigandt, Cristian F; Fabrizio de Iorio, Alicia

    2015-02-01

    This study assessed the contamination by heavy metals (Cr, Cu, Pb, Zn), and nutrients (N, P) in soils and native plants, and the effect of the concentration of those elements with the density of arbuscular-mycorrhizal (AM) spores in soil and colonization in roots from the riverside of the Matanza-Riachuelo River Basin (MRRB). The concentration of metals and nutrients in soils and plants (Eleocharis montana, Cyperus eragrostis, Hydrocotyle bonariensis) increased from the upper sites (8 km from headwaters) to the lower sites (6 km from the mouth of the Riachuelo River) of the basin. AM-colonization on the roots of H. bonariensis and spore density in soil decreased as the concentrations of metals in soil and plant tissues increased from the upper to lower sites of the basin within a consistent gradient of contamination associated with land use, soil disturbance, population, and chemicals discharged into the streams and rivers along the MRRB. The general trends for all metals in plant tissue were to have highest concentrations in roots, then in rhizomes and lowest in aerial biomass. The translocation (TF) and bioconcentration (BCF) factors decreased in plants which grow from the upper sites to the lower sites of the basin. The plants tolerated a wide range in type and quantity of contamination along the basin by concentrating more metals and nutrients in roots than in aboveground tissue. The AM spore density in soil and colonization in roots of H. bonariensis decreased with the increase of the degree of contamination (Dc) in soil. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Mycorrhiza of Dryopteris carthusiana in southern Poland

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    Juliusz Unrug

    2014-08-01

    Full Text Available The research on mycorrhiza of Dryopteris carthusiana from natural sites and those contaminated by heavy metals (Niepołomice Forest, both on lowlands and mountainous areas in Poland, was carried out. Mycorrhizal colonization of Arum-type was higher in ferns growing on tree stumps than in specimens developing directly on the soil. Additionally, an increase in mycorrhiza intensity and arbuscular richness with the rising ground humidity was observed. In comparison to natural sites, mycorrhizas from the areas contaminated by heavy metals were much less developed and the roots were often infected by parasites. Two morphotypes of mycorrhizal fungi have been described The most common was a fine endophyte (Glomales.

  16. Interação entre micorrizas arbusculares e ácido giberélico no desenvolvimento vegetativo de plantas de citrange carrizo Effect of arbuscular mycorrhizae and gibberelic acid interaction on vegetative growth of carrizo citrange seedlings

    Directory of Open Access Journals (Sweden)

    Paulo Vitor Dutra de Souza

    2000-10-01

    Full Text Available As plantas cítricas são, geralmente, dependentes dos fungos micorrízicos arbusculares (FMA. Há relatos indicando a existência de um intercâmbio hormonal entre as plantas e os FMA e também a comprovação de que a simbiose planta-FMA é beneficiada pela aplicação radicular de auxinas. Com o objetivo de verificar se esta interação também ocorre com outros grupos de fitorreguladores, submergiu-se, por 10 segundos, o sistema radicular de plântulas de citrange Carrizo (Citrus sinensis (L. Osb. X Poncirus trifoliata (L. Raf., previamente inoculadas, ou não, com Glomus intraradices Schenck & Smith, em uma solução de 10ppm de ácido giberélico (AG3. Após sete meses de cultivo em casa de vegetação, verificou-se que os FMA incrementaram o desenvolvimento vegetativo do citrange Carrizo, além de provocarem um aumento nos níveis foliares de P, Zn e Cu e induzirem a um decréscimo no conteúdo de Ca, Mg, Fe e Mn nos tecidos. Os FMA não afetaram os níveis foliares de N e K. O AG3 somente aumentou o diâmetro do colo das plantas, não modificando sua altura, peso seco da parte aérea e raízes, número de folhas e superfície foliar. O AG3 incrementou os níveis de P e Fe nos tecidos foliares, reduziu os teores de K e não modificou os teores dos demais nutrientes. O AG3 não alterou a colonização radicular com FMA. No entanto, verificou-se uma interação positiva e significativa entre os FMA e o AG3 sobre o desenvolvimento vegetativo das plantas de citrange Carrizo, indicando que o AG3 favorece a simbiose, permitindo uma redução no período de produção da muda.Citrus plants generaly depend on arbuscular mycorrhizal fungi (AMF. There are several reports indicating interaction between hormones and AMF. It has also been proven that plant and AMF symbiosis benefits from auxin aplication to roots. The present study had the objective to determine if plant-hormone interaction occurred with hormone groups other than auxins. Mycorrhizal

  17. Fungos micorrízicos arbusculares em estéril revegetado com Acacia mangium, após mineração de bauxita Colonization of arbuscular mycorrhizae fungi in substrate, after bauxite mining, vegetated with Acacia mangium

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    Ana Lucy Caproni

    2005-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a composição das comunidades de FMAs em áreas revegetadas com Acacia mangium após a mineração de bauxita na região de Porto Trombetas, PA. Foram coletadas amostras de solo compostas nos períodos seco e chuvoso, em áreas revegetadas com Acacia mangium, que receberam inóculos de Glomus clarum e Gigaspora margarita, com 1 e 5 anos de idade. Os solos foram revegetados sem a reposição do horizonte superficial orgânico. Os esporos dos fungos micorrízicos arbusculares (FMAs foram extraídos e identificados através de suas características morfológicas. Analisou-se a densidade de esporos e de espécies em cada amostra, a densidade relativa e a freqüência de ocorrência de cada espécie por período de amostragem, além do índice de abundância e freqüência (IAF. Sob o plantio de mudas de A. mangium, a densidade de esporos de FMAs foi elevada e aumentou com a idade, enquanto o número de espécies não variou. Glomus clarum produz alta densidade de esporos na fase inicial do plantio e declina com o tempo, e Gigaspora margarita não esporula nas condições edafoclimáticas locais. A maioria das espécies de FMA não apresenta o mesmo padrão de esporulação nos períodos seco e chuvoso.The objective of this work was to monitor the establishment of Gigaspora margarita and Glomus clarum in reclaimed areas after the bauxite mining in Porto Trombetas, PA, Brazil. Soil samples were collected during the dry and rainy periods under one and five-year-old Acacia mangium trees grown from seedlings that had been inoculated with Glomus clarum and Gigaspora margarita. The exposed subsoil was managed without replacing the organic soil layer. FMA spores were extracted and identified through their morphologic characteristics. Spore density and frequency of each species were determined in each sampling The index of abundance and frequency (IAF were estimated for all samples. Under A. mangium the arbuscular

  18. The effects of mineral nitrogen limitation, competition, arbuscular mycorrhiza, and their respective interactions, on morphological and chemical plant traits of Plantago lanceolata.

    Science.gov (United States)

    Pankoke, Helga; Höpfner, Ingo; Matuszak, Agnieszka; Beyschlag, Wolfram; Müller, Caroline

    2015-10-01

    Plants are sessile organisms that suffer from a multitude of challenges such as abiotic stress or the interactions with competitors, antagonists and symbionts, which influence their performance as well as their eco-physiological and biochemical responses in complex ways. In particular, the combination of different stressors and their impact on plant biomass production and the plant's ability to metabolically adjust to these challenges are less well understood. To study the effects of mineral nitrogen (N) availability, interspecific competition and the association with arbuscular mycorrhizal fungi (AMF) on biomass production, biomass allocation patterns (root/shoot ratio, specific leaf area) and metabolic responses, we chose the model organism Plantago lanceolata L. (Plantaginaceae). Plants were grown in a full factorial experiment. Biomass production and its allocation patterns were assessed at harvest, and the influence of the different treatments and their interactions on the plant metabolome were analysed using a metabolic fingerprinting approach with ultra-high performance liquid chromatography coupled with time-of-flight-mass spectrometry. Limited supply of mineral N caused the most pronounced changes with respect to plant biomass and biomass allocation patterns, and altered the concentrations of more than one third of the polar plant metabolome. Competition also impaired plant biomass production, yet affected the plant metabolome to a much lesser extent than limited mineral N supply. The interaction of competition and limited mineral N supply often caused additive changes on several traits. The association with AMF did not enhance biomass production, but altered biomass allocation patterns such as the root/shoot ratio and the specific leaf area. Interestingly, we did not find significant changes in the plant metabolome caused by AMF. A targeted analysis revealed that only limited mineral N supply reduced the concentrations of one of the main target defence

  19. Glomalin as an indicator of mycorrhizae in tropical agroecosystems

    Science.gov (United States)

    Arbuscular mycorrhizae (AM) are symbiotic mutualistic associations established between the roots of most plants and certain soil fungi. This symbiosis has positive effects on the development and nutrition of plants as it provides them with low mobility soil elements such as P, Zn and Cu. It also imp...

  20. 干旱环境下羊柴DSE与AM真菌和土壤因子关系研究%Relationships of dark septate endophytes with arbuscular mycorrhiza fungi and soil factors under Hedy sarum laeve in arid area

    Institute of Scientific and Technical Information of China (English)

    张娟; 贺学礼; 王晓乾; 许伟; 刘春卯; 赵丽莉

    2015-01-01

    Hedysarum laeve is one of the arid‐active and sand‐fixation plants that can not only conserve soil ,but also block the wind ,reduce soil erosion ,so as to maintain the balance and stability of arid areas .To elucidate the effect of wind and water erosion and the distribution of dark septate endophytes (DSE) ,soil samples (0-50 cm deep) were collected under H .laeve at three different sites (foot‐slope ,mid‐slope ,top‐slope) in Inner Mongolia in June in 2013 . The results showed that the roots of H .laeve could be highly infected by DSE .DSE could form typical symbiotic structures ,such as septate hyphae ,microsclerotia ,vesicle and so on . Soil sampling sites and depth had a significant effect on colonization levels of DSE . DSE hyphae ,vesicle and total colonization showed the following trend across sites :foot‐slope >top‐slope > mid‐slope .The arbuscular mycorrhiza (AM ) fungi colonization was foot‐slope >mid‐slope > top‐slope .DSE colonization had a positive correlation with AM fungal coloniza‐tion ,soil acid phosphatase and alkaline phosphatase .The soil nutrients were different caused by wind and water erosions in different sites .The effect of wind and water erosion of mid‐slope was the strongest .The results suggest that the colonization of DSE could be a better in‐dicator for the changes of soil resources .This research provides basis and references for fur‐ther clarifying the ecological functions of DSE and making full use of DSE to promote vegeta‐tion restoration and soil conservation in arid areas .%为了探明干旱环境下风蚀和水蚀对DSE (Dark septate endophytes)活动的影响,试验于2013年6月选取内蒙古正蓝旗青格勒图梁地,设置梁底、梁坡和梁顶不同样地,从羊柴(Hedysarum laeve)根围0~10、10~20、20~30、30~40、40~50 cm土层采集土壤样品,研究了DSE分布规律以及与AM (arbuscular mycorrhiza )真菌和土壤因子的相关性。结果表明

  1. Arbuscular mycorrhiza and kinetic parameters of phosphorus absorption by bean plants Micorriza arbuscular e os parâmetros cinéticos de absorção de fósforo pelo feijoeiro

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    Adriana Parada Dias da Silveira

    2004-04-01

    Full Text Available The mechanisms that determine greater P absorption by mycorrhizal plants are still not completely clear, and are attributed, in part, to an increase in the number of absorption sites promoted by the hyphae, and/or to a greater affinity of the colonized hypha or root carriers to P. The effect of mycorrhizae formed by Glomus etunicatum on the kinetic parameters of P absorption by the roots and on P influx in bean plants of the IAC-Carioca cultivar was evaluated, in two distinct plant development periods: at the onset of flowering and at the pod-filling stage (35 and 50 days after sowing, respectively. A mixture of sand and silica (9:1 was utilized as substrate and irrigated with nutrient solution. The kinetics assay was performed by the method of 32P depletion from the solution (depletion curve, using intact plants. Mycorrhization promoted greater growth and P absorption by bean plants, which was more conspicuously observed at the pod-filling stage. Mycorrhizal plants showed higher values of maximum ion uptake rate (Vmax and net P influx at the flowering stage. Lower minimum ion concentration (Cmin and Michaelis-Menten constant (Km values were verified in mycorrhizal plants at the pod-filling stage. Mycorrhizal plants also presented higher net P influx per plant, in both stages. Cmin was the kinetic parameter more intimately related to P absorption, and a significant correlation was obtained between this parameter and shoot P content and accumulation in bean plants.Os mecanismos envolvidos na maior absorção de P pela planta micorrizada ainda não estão totalmente esclarecidos, atribuindo-se, em parte, ao aumento no número de sítios de absorção promovido pela hifa e/ou maior afinidade dos carregadores da hifa ou da raiz colonizada ao P. Avaliou-se o efeito da micorriza formada por Glomus etunicatum nos parâmetros cinéticos da absorção radicular de P e no influxo de P em feijoeiro, cultivar IAC-Carioca, em duas épocas do ciclo da planta

  2. Mycorrhizas influence functional traits of two tallgrass prairie species.

    Science.gov (United States)

    Weremijewicz, Joanna; Seto, Kotaro

    2016-06-01

    Over the past decade, functional traits that influence plant performance and thus, population, community, and ecosystem biology have garnered increasing attention. Generally lacking, however, has been consideration of how ubiquitous arbuscular mycorrhizas influence plant allometric and stoichiometric functional traits. We assessed how plant dependence on and responsiveness to mycorrhizas influence plant functional traits of a warm-season, C4 grass, Andropogon gerardii Vitman, and the contrasting, cool-season, C3 grass, Elymus canadensis L. We grew both host species with and without inoculation with mycorrhizal fungi, across a broad gradient of soil phosphorus availabilities. Both host species were facultatively mycotrophic, able to grow without mycorrhizas at high soil phosphorus availability. A. gerardii was most dependent upon mycorrhizas and E. canadensis was weakly dependent, but highly responsive to mycorrhizas. The high dependence of A. gerardii on mycorrhizas resulted in higher tissue P and N concentrations of inoculated than noninoculated plants. When not inoculated, E. canadensis was able to take up both P and N in similar amounts to inoculated plants because of its weak dependence on mycorrhizas for nutrient uptake and its pronounced ability to change root-to-shoot ratios. Unlike other highly dependent species, A. gerardii had a high root-to-shoot ratio and was able to suppress colonization by mycorrhizal fungi at high soil fertilities. E. canadensis, however, was unable to suppress colonization and had a lower root-to shoot ratio than A. gerardii. The mycorrhiza-related functional traits of both host species likely influence their performance in nature: both species attained the maximum responsiveness from mycorrhizas at soil phosphorus availabilities similar to those of tallgrass prairies. Dependence upon mycorrhizas affects performance in the absence of mycorrhizas. Responsiveness to mycorrhizal fungi is also a function of the environment and

  3. Effects of Different Substrate with Different Arbuscular Mycorrhiza Fungi on the Infection and Growth to Amur Cork Tree%不同基质接种不同丛植菌根真菌对黄檗幼苗侵染及生长的影响

    Institute of Scientific and Technical Information of China (English)

    范继红; 李桂伶; 高琼

    2011-01-01

    通过盆栽接种试验,用4种丛枝菌根真菌(Arbuscular mycorrhizae,AM)接种黄檗1 a生实生苗,探索不同接种基质、不同菌种以及混合菌种条件下,内生丛枝菌根(Vesicalar-Arbuscular,VA)真菌对黄檗(Phellodendron amurense Rupr.)幼苗的侵染效果及对其生长量的影响.结果表明:不同基质条件下接种丛枝菌根真菌对寄主植物的生长发育的影响差异很大,就该试验菌种接种黄檗而言,以草炭∶蛭石∶沙子=1∶0.5∶1基质接种效果良好;通过混合接种与单独接种的侵染特性比较,凡是含G.mosseae和G.diaphanum菌种的接种处理侵染率高,显著提高了苗木的生长量,而含有G.versiforme和G.diaphanum的组合侵染率一直比较低,而且降低了G.mosseae和G.diaphanum的侵染效率.

  4. Colonização micorrízica arbuscular e tolerância ao mal-do-Panamá em mudas de banana-maçã Colonisation of arbuscular mycorrhiza and tolerance to Panama disease in seedlings of the maçã banana

    Directory of Open Access Journals (Sweden)

    Deusiane Batista Sampaio

    2012-09-01

    Full Text Available O objetivo desse trabalho foi avaliar o efeito da colonização micorrízica arbuscular na tolerância da bananeira, cv. Maçã, ao mal-do-Panamá, sob diferentes fontes de nutrientes. Utilizou-se um delineamento inteiramente casualizado com fatorial 2 x 4 [2 densidades de esporos de FMA nativos (D1 - 3.500 esporos kg-1 solo e D2 - 7.000 esporos kg-1 solo e 4 diferentes concentrações de fontes de nutrientes - três de solução nutritiva (SN 40%, SN 70% e SN 100% e uma de biofertilizante 100% (B4] com três repetições. Após o plantio inoculou-se Fusarium oxysporum f.sp. cubense e posteriormente avaliou-se matéria seca da parte aérea (MSPA, o teor de fósforo foliar (P, a colonização micorrízica, o pH do solo e o índice de severidade da doença (ID. As diferentes fontes de nutrientes influenciaram a matéria seca da parte aérea, o teor de fósforo, a colonização micorrízica e o índice de severidade da doença, porém não influenciaram o pH da solução do solo. O biofertilizante não atendeu à demanda nutricional das plantas, as quais se mostraram pouco desenvolvidas. Porém proporcionou intensa colonização micorrízica e menor índice de severidade da fusariose, o qual aumentou com a adubação mineral.The aim of this study was to evaluate the effect of the colonization of arbuscular mycorrhiza on the tolerance to Panama disease of the banana plant cv. maçã under different sources of nutrients. A completely randomized design was employed, having a 2 x 4 factorial [2 densities of native FMA spores (D1 - 3,500 spores kg-1 soil and D2 - 7000 spores kg-1 soil and four different concentrations of nutrient sources - three of a nutrient solution (SN 40%, SN 70% and SN 100% and a 100% solution of bio-fertiliser (B4], with three replications. After planting, the seedlings were inoculated with Fusarium oxysporum f.sp. cubense, and later the shoot dry matter, leaf phosphorus content, mycorrhizal colonization, soil pH and disease

  5. Effects of two arbuscular mycorrhizae fungi on some soil hydraulic properties and nutrient uptake by spring barley in an alkaline soil under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    2015-06-01

    Full Text Available In order to investigate the effects of mycorrhizal symbiosis on some soil hydraulic properties and nutrients uptake by spring barley, a greenhouse experiment was conducted based on a completely randomized blocks design with four replications, using two mycorrhizl fungi including Glomus intraradices (GI and Glomus etunicatum (GE and non-mycorrhizal (control treatments, in an alkaline coarse-textured soil. Results showed that GE and GI significantly increased (P< 0.01 field capacity (FC water content by 24.7 and 12.6%, permanent wilting point (PWP water content by 20.1 and 11.1%, available water capacity (AWC by 27.1 and 13.3%, micropores by 14.1 and 5%, mesopores by 27.8 and 20.8% and decreased macropores by 17.3 and 9.5% and saturated hydraulic conductivity by 88.2 and 68.8% relative to the control, respectively. Also, GE and GI fungi significantly increased (P< 0.01 uptake of phosphorus in barely seeds by 44.1 and 20.3% and in stem by 181 and 50.6% and potassium in seeds by 290.8 and 167.9%, respectively. It is concluded that mycorrhizal symbiosis, as a biological and sustainable method, improved hydraulic and chemical quality of the alkaline coarse-textured soil.

  6. Dipterocarpacae: mycorrhiza and regeneration.

    NARCIS (Netherlands)

    Smits, W.T.M.

    1994-01-01

    Research on mycorrhizae of Dipterocarpaccae is described, involving inventories of both mycorrhizae and sporocarps in natural forest and experimental work in nurseries, green houses, laboratories and gnotobiotic systems. An assessment is made of dipterocarp mycorrhizal specificity and a discussion i

  7. 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)

  8. An Introduction to Mycorrhizae.

    Science.gov (United States)

    Janerette, Carol A.

    1991-01-01

    The author describes relationships between the fungi called mycorrhizae and plants. Describes the classes of mycorrhizae and the importance of such fungi in plant growth. Presents clear micrographs of the fungi and their interactions with plant root cells. Provides technological applications of mycorrhizae in agriculture and discusses problems…

  9. Influence of Phosphorus and Nitrogen on Mycorrhizas in Winter Wheat

    Directory of Open Access Journals (Sweden)

    Roxana Vidican

    2016-11-01

    Full Text Available Intraradicular installation of vesicular-arbuscular mycorrhizas on the roots acts to amplify growth and to increase potential yield. Extraradicular network of hyphae developed by mycorrhizas acts as an extension of the root in order to access the nutrients located in unexplored areas. The percentage of roots occupied by mycorrhizal hyphae fluctuates heavily under the influence of fertilization. The highest values of the colonization parameters were recorded with a high level of phosphorus fertilization applied as phasial input. High doses of mineral fertilizers with phosphorus applied with seeding favors the development intraradicular hyphal networks in wheat roots.

  10. Effects of different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower under water stress

    Directory of Open Access Journals (Sweden)

    Mostafa Heidari

    2014-01-01

    Full Text Available The role of arbuscular mycorrhizal fungi in alleviating water stress is well documented. In order to study the effects of water stress and two different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower, a field experiment as split plot design with three replications was conducted in the Research Field Station, Zabol University, Zabol, Iran in 2011. Water stress treatments included control as 90% of field capacity (W1, 70% field capacity (W2 and 50% field capacity (W3 assigned to the main plots and two different mycorrhiza species, consisting of M1 = control (without any inoculation, M2 = Glumus mossea and M3 = Glumus etanicatum as sub plots. Results showed that by increasing water stress from control (W1 to W3 treatment, grain yield was significantly decreased. The reduction in the level of W3 was 15.05%. The content of potassium in seeds significantly decreased due to water stress but water stress upto W2 treatment increased the content of phosphorus, nitrogen and oil content of seeds. In between two species of mycorrhiza in sunflower plants, Glumus etanicatum had the highest effect on grain yield and these elements in seeds and increased both.

  11. Nutrição fosfática e micorriza arbuscular na redução da toxicidade de cádmio em trema [Trema micrantha (L. Blum.] Phosphate nutrition and arbuscular mycorrhiza on amelioration of cadmium toxicity in trema [Trema micrantha (L. Blum.

    Directory of Open Access Journals (Sweden)

    Cláudio Roberto Fonsêca Sousa Soares

    2007-10-01

    Full Text Available Neste trabalho, avaliaram-se os efeitos da nutrição fosfática e da micorriza arbuscular na toxicidade de Cd em Trema micrantha (L. Blum. Em um primeiro experimento, mudas de trema foram formadas em substrato contendo doses crescentes de P (0, 100, 200 e 400 mg dm-3 e com um tratamento de inoculação com Glomus etunicatum. Após crescimento por 60 dias, essas mudas foram transferidas para solução nutritiva de Clark sem Cd e suplementada com 5, 15 e 45 µmol L-1 de Cd e mantidas por mais 40 dias, quando os efeitos dos tratamentos foram avaliados. As influências do P na amenização da fitotoxidez de Cd foram também avaliados em outro experimento, aplicando-se simultaneamente e de forma combinada em solução, doses de P (0,07; 0,5; 1; e 2 mmol L-1 e de Cd (0, 5, 10 e 15 µmol L-1. Houve acentuada inibição no crescimento e colonização micorrízica da trema mesmo na dose mais baixa de Cd em solução (5 µmol L-1. Constatou-se que a melhoria da nutrição fosfática favoreceu o crescimento da planta, sendo isso associado à redução da toxicidade de Cd, enquanto a inoculação com G. etunicatum não teve o mesmo efeito. Encontrou-se uma relação inversa entre o aumento no fornecimento de P em solução e a absorção e acúmulo de Cd na trema. Análise da especiação química da solução indicou que o P não interferiu na disponibilidade de Cd em solução, o que evidencia que a ação amenizante do P se deve às interações na planta, possivelmente reduzindo a translocação do Cd.In the present study the effects of phosphorus nutrition and arbuscular mycorrhiza (AM were evaluated on Cd toxicity to Trema micrantha (L. Blum.. In a first experiment, trema seedlings were raised in a P-enriched substrate (0, 100, 200 and 400 mg dm-3 and with an AM treatment (inoculation with Glomus etunicatum. After sixty days of growth, plants were transferred to Clark nutrient solution either without Cd added or amended with this metal at

  12. MULTIPLICACIÓN DE HONGOS MICORRIZA ARBUSCULAR (H.M.A Y EFECTO DE LA MICORRIZACIÓN EN PLANTAS MICROPROPAGADAS DE BANANO (Musa AAA cv. Gran Enano (Musaceae MULTIPLICATION OF ARBUSCULAR MYCORRHIZAE FUNGI (AMF AND MYCORRHIZATION EFFECT IN MICROPROPAGATED PLANTS OF BANANA (Musa AAA cv. ‘Gran Enano’ (Musaceae

    Directory of Open Access Journals (Sweden)

    Carmen Elena Usuga Osorio

    2008-06-01

    Full Text Available Se evaluó el proceso de multiplicación de hongos que forman micorriza arbuscular (HMA, para lo cual se usaron diferentes tipos de inóculos entre ellos nativos de agroecosistemas bananeros del Urabá (Antioquia-Colombia, en sustrato sólido, con diferentes plantas hospedadoras y la infectividad y efectividad sobre plantas de banano (Musa AAA cv. Gran Enano. La colonización micorrizal promedio general de los HMA a las plantas trampa fue de 37,76 ± 21,86 %, con respecto a este porcentaje, las plantas B (Brachiaria decumbens y S (Sorgum vulgare fueron las que más favorecieron la simbiosis. Teniendo en cuenta el sustrato, el S2 (Arena 50 - suelo 50 y el S6 (Vermiculita 50-suelo 50 permitieron expresiones significativamente mayores respecto a los demás. El Sorgum vulgare y Pueraria phaseoloides y en el sustrato S1 (Arena 30 - suelo 70, se encontró un mayor número de esporas. La combinación planta-sustrato que más favoreció la asociación fue la planta trampa B en los sustratos S2 y S4 (cascarilla de arroz 50-suelo50 y la producción de esporas fueron las plantas K y S en el sustrato S1. La asociación micorrícica general en plantas de banano provenientes de cultivo de tejidos fue de 48,74 ± 30,44. No se encontraron diferencias significativas (P > 0,05 entre plantas de cero días con plantas de 30 de aclimatadas. Los inóculos que significativamente favorecieron la asociación fueron los provenientes de agroecosistemas bananeros al compararse con el inóculo comercial y el proveniente de ecosistemas naturales del Urabá. El mayor peso seco foliar y radical se encontró en plántulas de banano inoculadas con I5 (Inóculo proveniente de agroecosistema bananeros de la zona de estudio. Para las variables de crecimiento no se encontraron diferencias.The process of multiplication of arbuscular mycorrhizae fungi (AMF from indigenous banana agro-environments from Urabá (Antioquia - Colombia was evaluated, using solid substrate, with different

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

    Science.gov (United States)

    Bucher, Marcel; Wegmüller, Sarah; Drissner, David

    2009-08-01

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

  14. Mycorrhizae of poplars

    Science.gov (United States)

    R. C. Schultz; J. G. Isebrands; P. P. Kormanik

    1983-01-01

    Poplar hybrids, being screened for short-rotation intensive culture, can form ecto-, endo-, or ectendo-mycorrhizae or may be autotrophic. Different sections of the genus Populus tend to be selective in the type of mycorrhizae formed. Knowledge of which types are formed influences the kinds of propagule production, site preparation, and herbicide...

  15. 蚕豆/玉米间作接种AM真菌和根瘤菌对外源有机磷利用的影响%Effect of Inoculating Rhizobium and Arbuscular Mycorrhiza on Organic P Uptake in Faba Bean/maize Intercropping System

    Institute of Scientific and Technical Information of China (English)

    李淑敏; 李隆

    2011-01-01

    本研究以植酸钠为有机磷源,利用根系不同分隔方式的盆栽实验研究了蚕豆/玉米问作体系中,接种根瘤菌、AH真菌(Glomus mosseae)和双接种对间作体系利用有机磷的影响.结果表明:接种AM真菌使蚕豆和玉米的根际磷酸酶活性增加,显著提高了蚕豆/玉米间作体系对有机磷的吸收,双接种处理蚕豆和玉米总吸磷量平均比单接AH真菌和根瘤菌平均分别增加了11.7%和90.8%;相对干其它处理,在双接种条件下蚕豆对玉米吸收有机磷的促进作用更显著,不分隔和尼龙网分隔处理玉米的吸磷量比完全分隔处理分别提高43.4%(5.29mg)和17.9%(2.18 mg);在问作体系中同时接种AM真菌和根瘤菌能提高玉米的菌根侵染率,间作产量优势显著高于单接AM真菌和根瘤菌.%Pot experiments with different root barriers were carried out to investigate rhizobium, mycorrhizal/fungus and interaction of rhizobium and mycorrhizal fungus (Glomus mosseae) on organic P (phytate) uptake in faba bean/maize intercropping system.The results showed that: acid phosphatase activities in soil rhizosphere of faba bean and maize were improved due to inoculating arbuscular mycorrhiza.P uptake from organic P source in faba bean/maize intercropping system was enhanced significantly.Total P uptake by maize and faba bean inoculated with both microorganisms was increased 11.7% and 90.8% than that inoculated with single arbuscular mycorrhiza and rhizobium respectively.Compared with the other treatments, organic P uptake by maize was most significantly facilitated by associated faba bean.P uptake by maize with no barriers or mesh barriers was improved 43.4%( 5.29mg )and 17.9%( 2.18 mg)than that with solid barriers respectively.Mycorrhizal root colonization of maize inoculated with rhizobium and mycorrhizai fungus in maize/faba bean intercropping system was higher than that single inoculated with mycorrhizal fungus and rhizobium.Yield advantage

  16. Role of Arbuscular Mycorrhizal Fungi on Iris

    Directory of Open Access Journals (Sweden)

    CHEN Yuan

    2014-06-01

    Full Text Available For efficiency using the amphibious plant iris to restore polluted water, the promoting effect of different arbuscular mycorrhiza fungi(AMFon iris was investigated, by monitoring the plant growth index, the physicochemical properties of the soil and the plant photosynthesis indexes. The result showed that the promoting effects of the AMF on the aboveground part and the underground part of the iris were based on different mechanism. For the underground part of the iris, the AMF stimulated its growth through the nutrient enrichment which was performed by the enormous hypha network. The nitrogen absorbing rate of the G. mosseae and the G. intraradices infected iris increased about 71.75% and 42.55%, and the phosphorous absorbing rate increased 8.36% and 9.5% separately. For the aboveground part of the iris, the AMF strengthened the conductance of the leaves’ stomas to control the balance between the net photosynthesis rate and the transpiration rate, so that the utilization rate of water resources was optimized, the metabolic rate was accelerated and the growth of the plant was promoted eventually. In this study, the promoting effect of the G. mosseae on the photosynthesis rate of the iris was significantly better than that of the G. intraradices(P<0.05.

  17. Eficiência de fungos micorrízicos arbusculares isolados de solos sob diferentes sistemas de uso na região do Alto Solimões na Amazônia Effectiveness of arbuscular mycorrhiza fungal isolated from soils under different land use systems in the Alto Solimões river region in the Amazon

    Directory of Open Access Journals (Sweden)

    Gláucia Alves e Silva

    2009-09-01

    Full Text Available Os fungos micorrízicos arbusculares (FMAs são importantes componentes dos ecossistemas terrestres onde acredita-se desempenharem papel fundamental para a sustentabilidade destes. Estes fungos sofrem influência de diversos fatores antrópicos como o uso da terra, que modificam a estrutura e diversidade das comunidades podendo comprometer suas funções ecológicas. No presente estudo avaliou-se o comportamento de FMAs isolados de solos sob diferentes sistemas de uso (SUT. Fungos isolados de amostras de solo sob diferentes SUT foram testados em caupi [Vigna unguiculata (L. Walp] em condições controladas. Verificou-se que todos os cinqüenta e um fungos avaliados colonizaram o caupi, porém de modo muito diferenciado, tal como ocorreu para os efeitos destes na absorção de fósforo e crescimento da planta. A colonização variou de 1 a 68%, e os efeitos positivos no crescimento variaram de 33 a 148%, sendo mais comuns nos fungos isolados de pastagem e roça. O aumento nos teores de fósforo foi generalizado (95% dos fungos testados, no entanto, nem todos foram capazes de promover o crescimento do Caupi. Apenas 39% dos fungos foram considerados eficientes, sendo estes isolados de quase todos os SUT. Os tratamentos fúngicos de mais alta eficiência continham as espécies: A. foveata, Glomus sp.1, Acaulospora sp.1 e mistura dos dois primeiros mais E. infrequens e A. bireticulata-like. Os resultados indicam ampla diversidade de eficiência dos FMAs do Alto Solimões. Embora a eficiência não tenha relação direta com o SUT, a proporção de isolados eficientes variou com a origem de isolamento.Arbuscular mycorrhizal fungi (AMF are important components of terrestrial ecosystems where they are believed to play a fundamental role for their sustainability. These fungi are influenced by a number of anthropic factors such as, land use which modifies the structure and diversity of fungal communities and this may compromise their ecological functions

  18. Effects of mycorrhiza on growth and essential oil production in selected aromatic plants

    Directory of Open Access Journals (Sweden)

    Waed Tarraf

    2015-09-01

    Full Text Available Arbuscular mycorrhizal (AM symbiosis is widely investigated in aromatic herbs. Several studies have shown different effects on secondary metabolites, biomass production, as well as oil quantitative and qualitative aspects. The seeking to increase the yield of plants and their oils is an interesting topic in the world of medicinal and aromatic plant production. In tune with that, this study evaluated the effectiveness of two mycorrhiza fungi, Funneliformis mosseae (syn. Glomus mosseae and Septoglomus viscosum (syn. Glomus viscosum, on three species from Lamiaceae family: Salvia officinalis L., Origanum vulgare L., and Thymus vulgaris L. besides untreated control. It was found that the effect of symbiosis on growth was more favourable with S. viscosum than other AM fungus. The S. viscosum inoculation raised the yield of essential oil in oregano. Analysis of gas chromatography/mass spectrometry showed that manool obtained the highest abundance in leaf essential oil of inoculated sage; thymol was the major component whatever the treatment in thyme and lower relative content of carvacrol was reported with arbuscular mycorrhizal fungi inoculation in oregano. The results suggest the mycorrhizal inoculation as a promising technology in sustainable agricultural system to improve the plant productivity performance. Specific inocula are strategic to enhance the chemical profile of essential oils.

  19. Arbuscular mycorrhizal and dark septate endophyte associations of medicinal plants

    OpenAIRE

    Szymon Zubek; Janusz Błaszkowski; Piotr Mleczko

    2011-01-01

    Arbuscular mycorrhizal fungi (AMF) and dark septate endophyte (DSE) associations were studied in 36 medicinal plant species from 33 genera and 17 families, collected from the Botanical Garden of the Jagiellonian University in Kraków. Arbuscular mycorrhiza (AM) was found in 34 species (94%); 26 were of the Arum-type, 4 – Paris and 4 taxa revealed intermediate morpho­logy. The abundance of AMF hyphae in roots varied with particular species, ranging from 2.5% (Helianthus tuberosus) to 77.9% (Con...

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

    Directory of Open Access Journals (Sweden)

    Sławomir Kowalczyk

    2013-12-01

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

  1. Micorriza arbuscular em cupuaçu e pupunha cultivados em sistema agroflorestal e em monocultivo na Amazônia Central Arbuscular mycorrhiza in cupuaçu and peach palm cultivated in agroforestry and monoculture systems in the Central Amazon region

    Directory of Open Access Journals (Sweden)

    José Pereira da Silva Junior

    2006-05-01

    Full Text Available O objetivo deste trabalho foi avaliar a colonização micorrízica arbuscular em pupunha (Bactris gasipaes Kunth e cupuaçu (Theobroma grandiflorum (Willd ex Spring K. Schum cultivados em sistema agroflorestal e em monocultivo na Amazônia Central, em duas épocas do ano, e também identificar características anatômicas da formação dessa simbiose nessas espécies. Foram realizadas coletas de solo e raízes em duas estações, seca e chuvosa. A colonização micorrízica arbuscular no cupuaçu e na pupunha é alterada pelo sistema de manejo adotado, com taxas maiores de colonização no monocultivo. A densidade total dos esporos de fungos micorrízicos arbusculares sob o cupuaçu não é alterada pelo sistema de manejo ou pela época do ano, ao contrário do que ocorre sob a pupunha. Nessa cultura, a densidade de esporos foi maior sob sistema agroflorestal no período seco. A colonização micorrízica na pupunha apresenta dois padrões anatômicos, Paris e Arum, enquanto no cupuaçu ocorre o padrão Arum.The objective of this work was to evaluate the arbuscular mycorrhizal colonization in peach palm (Bactris gasipaes Kunth and cupuaçu (Theobroma grandiflorum (Willd ex Spring K. Schum, in agroforestry systems and monoculture in the Central Amazon region, and to identify anatomic characteristics of mycorrhizal colonization in these species. Soil and root samples were collected in the field, in the dry and rainy season. Mycorrhizal root colonization of cupuaçu and peach palm is affected by the management systems, with higher colonization rates in the monoculture system. Total spore density of the arbuscular mycorrhizal fungi under cupuaçu is not affected by management systems or season, but under peach palm this variation is season dependent. Mycorrhizal colonization of Arum and Paris types occur in peach palm, and only Arum type occurs in cupuaçu.

  2. Evaluation of Two Mycorrhiza Species and Nitroxin on Yield and Yield Components of Garlic (Allium sativum L. in an Ecological Agroecosystem

    Directory of Open Access Journals (Sweden)

    P Rezvani Moghaddam

    2016-02-01

    Full Text Available Introduction Maintenance of soil fertility is one of the most important issues affecting the sustainability of food production. The application of ecological inputs such as mycorrhiza and biofertilizers are one of those approaches which are needed to maintain soil fertility Biofetilizers include different types of free living organisms that convert unavailable nutrients to available forms and enhance root development and better seed germination. Plant growth promoting rhizobacteria (PGPR occupy the rhizosphere of many plant species and have beneficial effects on the host plant. They may directly and indirectly influence the plant growth. A direct mechanism would be to increase plant growth by supplying the plant with nutrients and hormones. Indirect mechanisms, on the other hand, include reduced susceptibility to diseases and acting as a form of defense referred to as induces systematic resistance. Mycorrhiza arbuscular fungi are other coexist microorganisms that improve soil fertility, nutrients cycling and agroecosystem health. Mycorrhizal fungi are the most abundant organisms in agricultural soils. Many researchers have pointed to the positive roles of mycorrhizal fungi on plants growth characteristics. Arbuscular mycorrhizas are found in 85% of all plant families and occur in many crop species. Mineral nutrients such as potassium, calcium, copper, zinc and iron are assimilated more quickly and in greater amounts by mycorrhizal plants. Arbuscular mycorrhizal inoculation has also been shown to increase plant resistance of pathogen attack. Garlic (Allium sativum L. is a very powerful medicinal plant that is often underestimated. Garlic is easy to grow and can be grown year-round in any mild climates. Garlic cloves are used for consumption (row and cooked or for medicinal purposes. They have a characteristic pungent, spicy flavor that mellows and sweetens considerably with cooking. Despite of many studies on the effects of mycorrhiza and

  3. Response of free-living soil protozoa and microorganisms to elevated atmospheric CO2 and presence of mycorrhiza

    DEFF Research Database (Denmark)

    Rønn, R.; Gavito, M.; Larsen, J.

    2002-01-01

    Possible interactions between mycorrhiza, atmospheric CO2, free-living soil microorganisms and protozoa were investigated in pot experimental systems. Pea plants (Pisum sativum L. cv. Solara) were grown under ambient (360 mul l(-1)) or elevated (700 mul l(-1)) atmospheric CO2 concentration...... with or without the presence of the arbuscular mycorrhizal (AM) fungus Glomus caledonium. It was hypothesised that (1) the populations of free-living soil protozoa would increase as a response to elevated CO2, (2) the effect of elevated CO2 on protozoa would be moderated by the presence of mycorrhiza and (3......) the presence of arbuscular mycorrhiza would affect soil protozoan numbers regardless of atmospheric CO2. After 3 weeks growth there was no difference in bacterial numbers (direct counts) in soil, but the number of free-living bacterial-feeding protozoa was significantly higher under elevated CO2...

  4. Soil lime level (pH) and VA-Mycorrhiza effects on growth responses of sweetgum seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Davis, E.A.; Young, J.L.; Linderman, R.G.

    1983-01-01

    Sequential greenhouse experiments limed a strongly acid surface and subsurface horizons of phosphorus-deficient Jory clay loam with increments of calcium carbonate to attain a range in soil pH from 5.0 to 8.1. In the absence of vesicular-arbuscular mycorrhizae (VAM), neither the organic matter-rich surface nor the organic matter-poor subsurface horizon supported growth of sweetgum seedlings at any pH despite regular nutrient supplements. The effects of pH, VAM, and soil horizon on nutrient accumulation and plant nutrient concentrations were variable. Nitrogen and phosphorus concentrations were generally higher in the VAM than in control seedlings, which suggests that host plant should be matched with VAM species adapted to particular soil and climate conditions to obtain maximum benefit from a mycorrhizal association. 18 references, 2 figures, 3 tables.

  5. Sugar exchanges in arbuscular mycorrhiza: RiMST5 and RiMST6, two novel Rhizophagus irregularis monosaccharide transporters, are involved in both sugar uptake from the soil and from the plant partner.

    Science.gov (United States)

    Ait Lahmidi, Nassima; Courty, Pierre-Emmanuel; Brulé, Daphnée; Chatagnier, Odile; Arnould, Christine; Doidy, Joan; Berta, Graziella; Lingua, Guido; Wipf, Daniel; Bonneau, Laurent

    2016-10-01

    Arbuscular mycorrhizal (AM) fungi are associated with about 80% of land plants. AM fungi provide inorganic nutrients to plants and in return up to 20% of the plant-fixed CO2 is transferred to the fungal symbionts. Since AM fungi are obligate biotrophs, unraveling how sugars are provided to the fungus partner is a key for understanding the functioning of the symbiosis. In this study, we identified two new monosaccharide transporters from Rhizophagus irregularis (RiMST5 and RiMST6) that we characterized as functional high affinity monosaccharide transporters. RiMST6 was characterized as a glucose specific, high affinity H(+) co-transporter. We provide experimental support for a primary role of both RiMST5 and RiMST6 in sugar uptake directly from the soil. The expression patterns of RiMSTs in response to partial light deprivation and to interaction with different host plants were investigated. Expression of genes coding for RiMSTs was transiently enhanced after 48 h of shading and was unambiguously dependent on the host plant species. These results cast doubt on the 'fair trade' principle under carbon-limiting conditions. Therefore, in light of these findings, the possible mechanisms involved in the modulation between mutualism and parasitism in plant-AM fungus interactions are discussed. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Mycorrhiza and heavy metal resistant bacteria enhance growth, nutrient uptake and alter metabolic profile of sorghum grown in marginal soil.

    Science.gov (United States)

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2016-08-01

    The main challenge for plants growing in nutrient poor, contaminated soil is biomass reduction, nutrient deficiency and presence of heavy metals. Our aim is to overcome these challenges using different microbial combinations in mining-impacted soil and focus on their physiological and biochemical impacts on a model plant system, which has multiple applications. In the current study, sorghum BTx623 seedlings grown in mining-impacted soil in greenhouse were subjected to plant growth promoting bacteria (PGPB or B) alone, PGPB with arbuscular mycorrhizal fungi (My), My alone and control group with no treatment. Root biomass and uptake of most of the elements showed significant increase in all treatment groups in comparison with control. Mycorrhiza group showed the best effect followed by My + B and B groups for uptake of majority of the elements by roots. On the contrary, biomass of both shoot and root was more influenced by B treatment than My + B and My treatments. Metabolomics identified compounds whose levels changed in roots of treatment groups significantly in comparison to control. Upregulation of stearic acid, sorbitol, sebacic acid and ferulic acid correlated positively with biomass and uptake of almost all elements. Two biochemical pathways, fatty acid biosynthesis and galactose metabolism, were regulated in all treatment groups. Three common pathways were upregulated only in My and My + B groups. Our results suggest that PGPB enhanced metabolic activities which resulted in increase in element uptake and sorghum root biomass whether accompanied with mycorrhiza or used solely.

  7. Sugar beet waste and its component ferulic acid inhibits external mycelium of arbuscular mycorrhizal fungus

    DEFF Research Database (Denmark)

    Medina, Almudena; Jakobsen, Iver; Egsgaard, Helge

    2011-01-01

    External arbuscular mycorrhiza (AM) mycelium plays an important role in soil while interacting with a range of biotic and abiotic factors. One example is the soil organic amendment sugar beet waste. The fermented Aspergillus niger–sugar beet waste (ASB) increases growth and P uptake by the AM...

  8. 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

  9. Estimation of the biomass of arbuscular mycorrhizal fungi in a linseed field

    DEFF Research Database (Denmark)

    Olsson, P.A.; Thingstrup, I.; Jakobsen, I.

    1999-01-01

    Linseed was grown in field plots included in a long-term P fertilisation experiment (0, 15 or 30 kg P ha(-1) yr(-1) for 20 yr). Two months before sowing, half of each plot man applied with dazomet to prevent the formation of arbuscular mycorrhiza (AM). The biomass of different groups of micro...

  10. Entrophospora schenckii and Pacispora franciscana, arbuscular mycorrhizal fungi (Glomeromycota new for Europe and Poland, respectively

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2014-08-01

    Full Text Available Morphological properties of spores of Pacispora franciscana, as well as spores and mycorrhizae of Entrophospora schenckii, arbuscular fungi of the phylum Glomeromycota found for the first time in Poland and Europe, respectively, are described and illustrated. Additionally, the known distribution of the two fungi is presented.

  11. ARBUSCULAR MYCORRHIZAL FUNGI - AN ESSENTIAL TOOL TO SUSTAINABLE VINEYARD DEVELOPMENT: A REVIEW

    Directory of Open Access Journals (Sweden)

    Gheorghe Cristian Popescu

    2016-12-01

    Full Text Available Grapevine is one of the most important horticultural perennial crops grown in many countries from worldwide. In this paper, we review the global benefits of arbuscular mycorrhiza application for grapevine production and the impact of viticultural practices for these natural microorganisms to establish symbiotic associations with vine roots. This review aims to provide a brief overview of the status of and to outline the most important application and effects of AMF in viticulture in order to increase the sustainability of vineyards. Viticulture has to adapt to new challenges of pest and chemicals fertilizers management, climate change, global urbanization, land erosions, increasing droughts, world population growth and others factors that can affect the sustainability of viticultural production systems. One of eco-friendly approaches is to use the application of arbuscular mycorrhiza fungi (AMF. Response of grapevine to AMF application demonstrated a lot of benefits for viticultural ecosystems. Technologies on sustainable agriculture and conservation of ecosystems vineyards may consider arbuscular mycorrhiza fungi as biofertilizers. Arbuscular mycorrhiza fungi could be an effective tool for improving the agro-enviromental perfomance in viticultural farms.

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

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2013-12-01

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

  13. Gibberellins interfere with symbiosis signaling and gene expression and alter colonization by arbuscular mycorrhizal fungi in Lotus japonicus.

    Science.gov (United States)

    Takeda, Naoya; Handa, Yoshihiro; Tsuzuki, Syusaku; Kojima, Mikiko; Sakakibara, Hitoshi; Kawaguchi, Masayoshi

    2015-02-01

    Arbuscular mycorrhiza is a mutualistic plant-fungus interaction that confers great advantages for plant growth. Arbuscular mycorrhizal (AM) fungi enter the host root and form symbiotic structures that facilitate nutrient supplies between the symbionts. The gibberellins (GAs) are phytohormones known to inhibit AM fungal infection. However, our transcriptome analysis and phytohormone quantification revealed GA accumulation in the roots of Lotus japonicus infected with AM fungi, suggesting that de novo GA synthesis plays a role in arbuscular mycorrhiza development. We found pleiotropic effects of GAs on the AM fungal infection. In particular, the morphology of AM fungal colonization was drastically altered by the status of GA signaling in the host root. Exogenous GA treatment inhibited AM hyphal entry into the host root and suppressed the expression of Reduced Arbuscular Mycorrhization1 (RAM1) and RAM2 homologs that function in hyphal entry and arbuscule formation. On the other hand, inhibition of GA biosynthesis or suppression of GA signaling also affected arbuscular mycorrhiza development in the host root. Low-GA conditions suppressed arbuscular mycorrhiza-induced subtilisin-like serine protease1 (SbtM1) expression that is required for AM fungal colonization and reduced hyphal branching in the host root. The reduced hyphal branching and SbtM1 expression caused by the inhibition of GA biosynthesis were recovered by GA treatment, supporting the theory that insufficient GA signaling causes the inhibitory effects on arbuscular mycorrhiza development. Most studies have focused on the negative role of GA signaling, whereas our study demonstrates that GA signaling also positively interacts with symbiotic responses and promotes AM colonization of the host root. © 2015 American Society of Plant Biologists. All Rights Reserved.

  14. Gibberellins Interfere with Symbiosis Signaling and Gene Expression and Alter Colonization by Arbuscular Mycorrhizal Fungi in Lotus japonicus1

    Science.gov (United States)

    Takeda, Naoya; Handa, Yoshihiro; Tsuzuki, Syusaku; Kojima, Mikiko; Sakakibara, Hitoshi; Kawaguchi, Masayoshi

    2015-01-01

    Arbuscular mycorrhiza is a mutualistic plant-fungus interaction that confers great advantages for plant growth. Arbuscular mycorrhizal (AM) fungi enter the host root and form symbiotic structures that facilitate nutrient supplies between the symbionts. The gibberellins (GAs) are phytohormones known to inhibit AM fungal infection. However, our transcriptome analysis and phytohormone quantification revealed GA accumulation in the roots of Lotus japonicus infected with AM fungi, suggesting that de novo GA synthesis plays a role in arbuscular mycorrhiza development. We found pleiotropic effects of GAs on the AM fungal infection. In particular, the morphology of AM fungal colonization was drastically altered by the status of GA signaling in the host root. Exogenous GA treatment inhibited AM hyphal entry into the host root and suppressed the expression of Reduced Arbuscular Mycorrhization1 (RAM1) and RAM2 homologs that function in hyphal entry and arbuscule formation. On the other hand, inhibition of GA biosynthesis or suppression of GA signaling also affected arbuscular mycorrhiza development in the host root. Low-GA conditions suppressed arbuscular mycorrhiza-induced subtilisin-like serine protease1 (SbtM1) expression that is required for AM fungal colonization and reduced hyphal branching in the host root. The reduced hyphal branching and SbtM1 expression caused by the inhibition of GA biosynthesis were recovered by GA treatment, supporting the theory that insufficient GA signaling causes the inhibitory effects on arbuscular mycorrhiza development. Most studies have focused on the negative role of GA signaling, whereas our study demonstrates that GA signaling also positively interacts with symbiotic responses and promotes AM colonization of the host root. PMID:25527715

  15. Effect of arbuscular mycorrhizal fungi and pesticides on Cynara cardunculus growth

    Directory of Open Access Journals (Sweden)

    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.

  16. Epiphytic and terrestrial mycorrhizas in a lower montane Costa Rican cloud forest.

    Science.gov (United States)

    Rains, Kai Coshow; Nadkarni, Nalini M; Bledsoe, Caroline S

    2003-10-01

    The epiphyte community is the most diverse plant community in neotropical cloud forests and its collective biomass can exceed that of the terrestrial shrubs and herbs. However, little is known about the role of mycorrhizas in this community. We assessed the mycorrhizal status of epiphytic (Araceae, Clusiaceae, Ericaceae, and Piperaceae) and terrestrial (Clusiaceae, Ericaceae) plants in a lower montane cloud forest in Costa Rica. Arbuscular mycorrhizas were observed in taxa from Araceae and Clusiaceae; ericoid mycorrhizas were observed in ericaceous plants. This is the first report of intracellular hyphal coils characteristic of ericoid mycorrhizas in roots of Cavendishia melastomoides, Disterigma humboldtii, and Gaultheria erecta. Ericaceous roots were also covered by an intermittent hyphal mantle that penetrated between epidermal cells. Mantles, observed uniquely on ericaceous roots, were more abundant on terrestrial than on epiphytic roots. Mantle abundance was negatively correlated with gravimetric soil water content for epiphytic samples. Dark septate endophytic (DSE) fungi colonized roots of all four families. For the common epiphyte D. humboldtii, DSE structures were most abundant on samples collected from exposed microsites in the canopy. The presence of mycorrhizas in all epiphytes except Peperomia sp. suggests that inoculum levels and environmental conditions in the canopy of tropical cloud forests are generally conducive to the formation of mycorrhizas. These may impact nutrient and water dynamics in arboreal ecosystems.

  17. Biochemical Defenses Induced by Mycorrhizae Fungi Glomus Mosseae in Controlling Strawberry Fusarium Wilt.

    Science.gov (United States)

    Yanan, Wang; Xusheng, Zhao; Baozhong, Yin; Wenchao, Zhen; Jintang, Guo

    2015-01-01

    The effect of VAM on reducing wilt caused by Fusarium oxysporum Schlecht. f.sp. fragariae Winks et Williams (FO) infection in strawberry and the possible mechanisms involved were investigated. Two key substance involved in disease defenses, lignin and hydroxyproline-rich glycoprotein were induced and formed in the cell wall of strawberry root, and the peak content of lignin and hydroxyproline-rich glycoprotein occurred on the 25(th) day (149.52mg/g) and on the 15(th) day (10.08 mg/g). The activity of protective enzymes SOD, POD and CAT inoculation with VAM significantly increased when compared with the control under both CK (natural growth) and inoculated with FO. The conductivity of VAM plus FO treatment was higher than the CK treatment, but significantly was lower than the FO treatment.

  18. Mycorrhiza-induced resistance: more than the sum of its parts?

    OpenAIRE

    Cameron, D.D.; Neal, A.L.; van Wees, S.C.M.; Ton, J.

    2013-01-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This ‘mycorrhiza-induced resistance’ (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely re...

  19. Effect of Mycorrhiza Symbiosis on Yield, Yield Components and Water Use Efficiency of Sesame (Sesamum indicum L. Affected by Different Irrigation Regimes in Mashhad Condition

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    A Koocheki

    2016-02-01

    Full Text Available Introduction Plant association with mycorrhiza has been considered as one of the options to improve input efficiency particularly for water and nutrient - (Allen and Musik, 1993; Bolan, 1991. This has been due to kncreasing the absorbing area of the root and therefore better contact with water and nutrients. Inoculation with mycorrhiza enhances nutrient uptake with low immobility such as phosphorus and solphur-, improve association and could be an option to drought and other environmental abnormalities such as salinity (Rice et al., 2002. Moreover, higher water use efficiency (WUE for crops -has been reported in the literatures (Sekhara and Reddy, 1993.The sustainable use of scarce water resources in Iran is a priority for agricultural development. The pressure of using water in agriculture sector is increasing, so creating ways to improve water-use efficiency and taking a full advantage of available water are crucial. Water stress reduce crop yield by impairing the growth of crop canopy and biomass. Scheduling water application is very crucial for efficient use of drip irrigation system, as excessive irrigation reduces yield, while inadequate irrigation causes water stress and reduces production. The aim of present study was to evaluate the symbiotic effect of mycorrhiza on yield, yield components and water use efficiency of sesame under different irrigation regimes in Mashhad. Material and Methods In order to investigate the impact of inoculation with two species of Arbuscular mycorrhiza fungi on yield, yield components and water use efficiency (WUE of sesame (Sesamum indicum L. under different irrigation regimes, an experiment was conducted as split plot based on a randomized complete block design with three replications during two growing seasons 2009-2010 and 2010-2011 at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad.. The experimental factors were three irrigation regimes include 2000, 3000 and

  20. Mycorrhiza-induced resistance and priming of plant defenses.

    Science.gov (United States)

    Jung, Sabine C; Martinez-Medina, Ainhoa; Lopez-Raez, Juan A; Pozo, Maria J

    2012-06-01

    Symbioses between plants and beneficial soil microorganisms like arbuscular-mycorrhizal fungi (AMF) are known to promote plant growth and help plants to cope with biotic and abiotic stresses. Profound physiological changes take place in the host plant upon root colonization by AMF affecting the interactions with a wide range of organisms below- and above-ground. Protective effects of the symbiosis against pathogens, pests, and parasitic plants have been described for many plant species, including agriculturally important crop varieties. Besides mechanisms such as improved plant nutrition and competition, experimental evidence supports a major role of plant defenses in the observed protection. During mycorrhiza establishment, modulation of plant defense responses occurs thus achieving a functional symbiosis. As a consequence of this modulation, a mild, but effective activation of the plant immune responses seems to occur, not only locally but also systemically. This activation leads to a primed state of the plant that allows a more efficient activation of defense mechanisms in response to attack by potential enemies. Here, we give an overview of the impact on interactions between mycorrhizal plants and pathogens, herbivores, and parasitic plants, and we summarize the current knowledge of the underlying mechanisms. We focus on the priming of jasmonate-regulated plant defense mechanisms that play a central role in the induction of resistance by arbuscular mycorrhizas.

  1. Micorrizas arbusculares

    OpenAIRE

    2007-01-01

    Las micorrizas son asociaciones simbióticas mutualistas de diversos tipos que se establecen entre ciertos hongos del suelo y las raíces de una planta. De entre estas asociaciones destacan por su ubicuidad las endomicorrizas o micorrizas arbusculares, aparentemente las más comunes en la naturaleza, ya que ocurren en la mayoría de los suelos y en el 90% de las familias de plantas de la tierra. La ubicación taxonómica de los hongo sendomicorrízicos ha evolucionado recientemente a partir de co...

  2. Phylogenetic distribution and evolution of mycorrhizas in land plants.

    Science.gov (United States)

    Wang, B; Qiu, Y-L

    2006-07-01

    A survey of 659 papers mostly published since 1987 was conducted to compile a checklist of mycorrhizal occurrence among 3,617 species (263 families) of land plants. A plant phylogeny was then used to map the mycorrhizal information to examine evolutionary patterns. Several findings from this survey enhance our understanding of the roles of mycorrhizas in the origin and subsequent diversification of land plants. First, 80 and 92% of surveyed land plant species and families are mycorrhizal. Second, arbuscular mycorrhiza (AM) is the predominant and ancestral type of mycorrhiza in land plants. Its occurrence in a vast majority of land plants and early-diverging lineages of liverworts suggests that the origin of AM probably coincided with the origin of land plants. Third, ectomycorrhiza (ECM) and its derived types independently evolved from AM many times through parallel evolution. Coevolution between plant and fungal partners in ECM and its derived types has probably contributed to diversification of both plant hosts and fungal symbionts. Fourth, mycoheterotrophy and loss of the mycorrhizal condition also evolved many times independently in land plants through parallel evolution.

  3. Plant responsiveness to mycorrhizas differs from dependence upon mycorrhizas.

    Science.gov (United States)

    Janos, David P

    2007-03-01

    Soil phosphorus response curves of plants with and without mycorrhizas reflect two different, but complementary, phenomena. The first, plant responsiveness to mycorrhizas, is represented by the difference in growth between plants with and without mycorrhizas at any designated level of phosphorus availability. This is also a measure of mycorrhizal fungus effectiveness. The second, the lowest level of phosphorus availability at which plants can grow without mycorrhizas, is here termed dependence upon mycorrhizas. The latter definition differs from conventional usage which fails to distinguish dependence from responsiveness. Sigmoid curves generated by the three-parameter, logistic equation generally can model the responses of plants to mycorrhizas and phosphorus addition and can be used to assess responsiveness, effectiveness, and dependence. Such curves reveal that plant responsiveness or fungus effectiveness determined at a single level of phosphorus availability may be misleading when used to compare different host species' intrinsic capacities to respond to different mycorrhizal fungus species. Instead, the same relative position should be evaluated among phosphorus response curves for different species combinations. Dependence of a plant species known to benefit from mycorrhizas can be assessed with reference to only the phosphorus response curve of plants without mycorrhizas. Dependence is a constitutive property of plant species that can be used to classify them as facultatively or obligately mycotrophic. Dependence is a plant attribute upon which natural selection can act, but responsiveness and effectiveness cannot be selected directly because they are emergent properties of the interaction between plant and fungus species.

  4. Crescimento de mudas de peroba rosa em resposta à inoculação com fungos micorrízicos arbusculares Growth responses of peroba rosa seedlings due to arbuscular mycorrhizal fungi inoculation

    Directory of Open Access Journals (Sweden)

    Oswaldo Machineski

    2009-04-01

    Full Text Available O objetivo neste trabalho foi de avaliar o efeito da inoculação de fungos micorrízicos arbusculares no crescimento de mudas de peroba rosa (Aspidosperma polyneuron. O experimento foi conduzido em delineamento experimental, inteiramente casualizado, em casa de vegetação com seis repetições. Utilizou-se mistura de solo e areia (3:1, desinfestado como substrato, com os seguintes tratamentos de inoculação: Gigaspora margarita, Glomus clarum, Scutellospora heterogama, Acaulospora scrobiculata e uma mistura de fungos micorrízicos arbusculares (FMA. Após 120 dias, observou-se que a colonização micorrízica radicular foi de 28,3% a 48,4% para a mistura de FMA e para G. margarita, respectivamente. As plantas inoculadas com G. margarita e G. clarum apresentaram maior crescimento, indicando o potencial da inoculação desses fungos na produção de mudas.The aim of this study was to examine the effects of arbuscular mycorrhizal fungi (AMF inoculation on Aspidosperma polyneuron seedlings growth. The experiment was conducted under greenhouse conditions in a randomized design using a disinfected mixture of soil + sand (3:1 with the following treatments: Gigaspora margarita, Glomus clarum, Scutellospora heterogama, Acaulospora scrobiculata, a mixture of arbuscular mycorrhizae fungi (AMF and a non-inoculated control with six replicates. After 120 days of seed germination, it was observed that root colonization was from 28.3% to 48.4% for mixture of AMF and G. margarita, respectively. The plants inoculated with G. margarita or G. clarum showed higher growth than other treatments, which evidence the potential of AMF inoculation in seedlings production.

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

    NARCIS (Netherlands)

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

    2000-01-01

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

  6. 菌根真菌促进植物磷吸收研究进展%Advance of plant phosphorus uptake improved by mycorrhiza fungi

    Institute of Scientific and Technical Information of China (English)

    曹庆芹; 冯永庆; 刘玉芬; 郭献平; 张国庆; 秦岭

    2011-01-01

    In the soil the concentration of soluble phosphorus is very scarce, which is one of main factors limiting plant growth. Plant-fungus has evolved a symbiosis way called mycorrhiza to significantly increase plant Pi uptake ability from soil, and improve plant growth. Here we first summarize the morphological characters of two types of mycorrhizae including ecto-mycorrhiza and arbuscular mycorrhiza. Then we summarize the studies on mechanisms of improving Pi absorbance, and the mycorrhiza-specific and inducible phosphate transporter identified in plant.Finally we introduce the current understanding of signaling pathway during arbuscular mycorrhiza symbiosis.%土壤中低浓度的有效磷水平成为限制植物生长发育的主要因素.植物-真菌菌根共生可以显著提高植物吸收土壤中磷的能力,促进植物生长发育.该文对土壤中磷酸盐的形式、丛枝状菌根和外生菌根两种菌根类型的形态学特征和促磷吸收的发生机制、植物中已克隆的菌根特异性或诱导性磷转运蛋白,以及丛枝状真菌共生信号转导途径等进行了综述.

  7. Propágulos de fungos micorrízicos arbusculares em solos deficientes em fósforo sob diferentes usos, da região semi-arida no nordeste do Brasil Propagules of arbuscular mycorrhizae in p-deficient soils under different land uses, in semi-arid NE Brazil

    Directory of Open Access Journals (Sweden)

    Regina Lúcia Félix de Aguiar Lima

    2007-04-01

    Full Text Available A conversão de áreas de caatinga em agricultura e pecuária de subsistência é uma das características marcantes da região semi-árida do Nordeste do Brasil. O presente estudo investigou o efeito dessa conversão sobre os propágulos de fungos micorrízicos arbusculares (FMA em 10 locais diferentes, distribuídos nos Estados da Paraíba e de Pernambuco. Cada local consistiu de uma área de vegetação nativa (caatinga contígua com uma área cultivada, na mesma posição de encosta. Amostras de solo foram coletadas a intervalos de 20-30 m, nas profundidades de 0-7,5 e 7,5-15 cm (10 locais x 2 usos do solo x 2 profundidades com 4 pontos amostrais ao longo de uma transecção que cruzava as áreas contíguas. As raízes (The conversion of tropical dry forest into areas used for subsistence agriculture or livestock production is a common feature of the semi-arid region of NE Brazil. Our study looked into the effect of these land use changes on propagules of arbuscular mycorrhizal fungi (AMF at ten sites distributed in the states of Paraíba and Pernambuco. Each site consisted of an area under native vegetation (Dry-Forest adjacent to a cultivated area in the same slope position. Soil samples were taken at distance intervals of 20-30 m from two depths (0-7.5 and 7.5-15 cm along a transect crossing the adjacent areas (10 sites x 2 land uses x 2 depths x 4 sampling points. Roots (< 2 mm found in the soil samples (n = 160 were stained with trypan blue to assess the percentage of AMF colonization as well as the type of fungal structures. The AMF spores were separated from soil by wet sieving, incubated in iodonitrotetrazolium chloride (INT solution and counted; those stained with INT were considered viable. Soil samples were analyzed for resin-extractable P and total organic carbon (TOC. For data analysis, the 10 areas under dry forest were separated in two sub-groups: Undisturbed-Dry-Forest (UDF, n = 6 and Disturbed-Dry-Forest (DDF, n = 4, owing

  8. Arbuscular mycorrhizal colonization and nodulation improve flooding tolerance in Pterocarpus officinalis Jacq. seedlings.

    Science.gov (United States)

    Fougnies, L; Renciot, S; Muller, F; Plenchette, C; Prin, Y; de Faria, S M; Bouvet, J M; Sylla, S Nd; Dreyfus, B; Bâ, A M

    2007-05-01

    Pterocarpus officinalis (Jacq.) seedlings inoculated with the arbuscular mycorrhizal fungus, Glomus intraradices, and the strain of Bradyrhizobium sp. (UAG 11A) were grown under stem-flooded or nonflooded conditions for 13 weeks after 4 weeks of nonflooded pretreatment under greenhouse conditions. Flooding of P. officinalis seedlings induced several morphological and physiological adaptive mechanisms, including formation of hypertrophied lenticels and aerenchyma tissue and production of adventitious roots on submerged portions of the stem. Flooding also resulted in an increase in collar diameter and leaf, stem, root, and total dry weights, regardless of inoculation. Under flooding, arbuscular mycorrhizas were well developed on root systems and adventitious roots compared with inoculated root systems under nonflooding condition. Arbuscular mycorrhizas made noteworthy contributions to the flood tolerance of P. officinalis seedlings by improving plant growth and P acquisition in leaves. We report in this study the novel occurrence of nodules connected vascularly to the stem and nodule and arbuscular mycorrhizas on adventitious roots of P. officinalis seedlings. Root nodules appeared more efficient fixing N(2) than stem nodules were. Beneficial effect of nodulation in terms of total dry weight and N acquisition in leaves was particularly noted in seedlings growing under flooding conditions. There was no additive effect of arbuscular mycorrhizas and nodulation on plant growth and nutrition in either flooding treatment. The results suggest that the development of adventitious roots, aerenchyma tissue, and hypertrophied lenticels may play a major role in flooded tolerance of P. officinalis symbiosis by increasing oxygen diffusion to the submerged part of the stem and root zone, and therefore contribute to plant growth and nutrition.

  9. Tuber melanosporum spread within sub-optimal climatic zones is controlled by fruiting triggers and not mycorrhiza survival

    Directory of Open Access Journals (Sweden)

    Paul W. Thomas

    2014-07-01

    Full Text Available Tuber melanosporum is the most valuable of all cultivatable truffle species. Farming of this species spans every continent with the exception of Antarctica. Tuber aestivum (syn. T. uncinatum and Tuber brumale are truffle species that have similar host plant preference and a similar affinity for calcareous soils as T. melanosporum, but occur over a broader geographic zone. The geographic limit of T. melanosporum is thought to be climatically dictated but it is not known whether this is due to an impact on mycorrhizal survival or climatically-derived fruiting triggers. Here, data is compiled from five cultivated research sites in the climatically sub-optimal conditions of the UK in order to address this question. Here we show: (iTuber melanosporum mycorrhiza can survive and grow in sub-optimal climatic conditions. (iiIt is climatically-derived fruiting triggers and not ectomycorrhiza survival that dictate the climatic preferences and geographic spread of T. melanosporum. (iiiImportant climatic parameters for potential fruiting triggers are sunshine hours, summer rainfall and summer temperatures.   The data presented here not only aid our understanding of the ecological parameters of T. melanosporum but also have a practical application for truffle cultivators in choosing suitable locations for a plantation.

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

    Science.gov (United States)

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

    2012-11-01

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

  11. The arbuscular mycorrhizal fungus, Glomus irregulare, controls the mycotoxin production of Fusarium sambucinum in the pathogenesis of potato.

    Science.gov (United States)

    Ismail, Youssef; McCormick, Susan; Hijri, Mohamed

    2013-11-01

    Trichothecenes are an important family of mycotoxins produced by several species of the genus Fusarium. These fungi cause serious disease on infected plants and postharvest storage of crops, and the toxins can cause health problems for humans and animals. Unfortunately, there are few methods for controlling mycotoxin production by fungal pathogens, and most rely on chemicals, creating therefore subsequent problems of chemical resistance. We tested the impact of the symbiotic arbuscular mycorrhizal fungus Glomus irregulare on a trichothecene-producing strain of Fusarium sambucinum isolated from naturally infected potato plants. Using dual in vitro cultures, we showed that G. irregulare inhibited the growth of F. sambucinum and significantly reduced the production of the trichothecene 4, 15-diacetoxyscirpenol (DAS). Furthermore, using G. irregulare-colonized potato plants infected with F. sambucinum, we found that the G. irregulare treatment inhibited the production of DAS in roots and tubers. Thus, in addition to the known beneficial effect of mycorrhizal symbiosis on plant growth, we found that G. irregulare controlled the growth of a virulent fungal pathogen and reduced production of a mycotoxin. This previously undescribed, biological control of Fusarium mycotoxin production by G. irregulare has potential implications for improved potato crop production and food safety.

  12. Red/Far Red Light Controls Arbuscular Mycorrhizal Colonization via Jasmonic Acid and Strigolactone Signaling.

    Science.gov (United States)

    Nagata, Maki; Yamamoto, Naoya; Shigeyama, Tamaki; Terasawa, Yohei; Anai, Toyoaki; Sakai, Tatsuya; Inada, Sayaka; Arima, Susumu; Hashiguchi, Masatsugu; Akashi, Ryo; Nakayama, Hideyuki; Ueno, Daisuke; Hirsch, Ann M; Suzuki, Akihiro

    2015-11-01

    Establishment of a nitrogen-fixing symbiosis between legumes and rhizobia not only requires sufficient photosynthate, but also the sensing of the ratio of red to far red (R/FR) light. Here, we show that R/FR light sensing also positively influences the arbuscular mycorrhizal (AM) symbiosis of a legume and a non-legume through jasmonic acid (JA) and strigolactone (SL) signaling. The level of AM colonization in high R/FR light-grown tomato and Lotus japonicus significantly increased compared with that determined for low R/FR light-grown plants. Transcripts for JA-related genes were also elevated under high R/FR conditions. The root exudates derived from high R/FR light-grown plants contained more (+)-5-deoxystrigol, an AM-fungal hyphal branching inducer, than those from low R/FR light-grown plants. In summary, high R/FR light changes not only the levels of JA and SL synthesis, but also the composition of plant root exudates released into the rhizosphere, in this way augmenting the AM symbiosis.

  13. Arbuscular mycorrhiza contribution to the growth performance and ...

    African Journals Online (AJOL)

    hope&shola

    2009-06-12

    Jun 12, 2009 ... GM and GI fungi enhanced the growth of Helianthus annuus and the ... Key words: Glomus mosseae, Glomus intraradices, Helianthus annuus, phytoremediation, polluted soil. ... Cd, Cr, Ni, Pb and Zn from aqueous solutions.

  14. Micorrizas arbusculares

    Directory of Open Access Journals (Sweden)

    Luis I. Aguilera Gómez

    2007-01-01

    Full Text Available Las micorrizas son asociaciones simbióticas mutualistas de diversos tipos que se establecen entre ciertos hongos del suelo y las raíces de una planta. De entre estas asociaciones destacan por su ubicuidad las endomicorrizas o micorrizas arbusculares, aparentemente las más comunes en la naturaleza, ya que ocurren en la mayoría de los suelos y en el 90% de las familias de plantas de la tierra. La ubicación taxonómica de los hongo sendomicorrízicos ha evolucionado recientemente a partir de consideraciones basadas en la revisión de esporas fósiles, las relaciones entre las diferentes categorías de los hongos actuales, su morfología y su comportamiento fisiológico. La importancia de las endomicorrizas ha aumentado en la última década debido a numerosos reportes de efectos benéficos sobre las plantas, que van desde incrementos en la absorción de nutrimentos en el suelo, su influencia sobre las relaciones hídricas y la protección contra agentes patógenos, hasta el importante papel ecológico que estas asociaciones parecen jugar en la sucesión de especies en las comunidades vegetales naturales.

  15. Rhizobacteria Selection to Enhance Spore Germination and Hyphal Length of Arbuscular Mycorrhizal Fungi in Vitro

    OpenAIRE

    Cecep, Hidayat; Dedeh H. Arief; Nurbaity, Ane; Sauman, Jajang

    2013-01-01

    In natural condition, Arbuscular Mycorrhizal Fungi (AMF) are surrounded by bacteria that help fungi symbiosis. The research aimed to get rhizobacteria that can act as Mycorrhiza Helper Bacteria (MHB) had been held at Soil Biology and Biotechnology Laboratory Faculty of Agriculture Unpad from February to March 2012. The experimental design used was completely randomized design with 11 treatments (bo= without rhizobacteria, b1= Pseudomonas diminuta, b2 = Bacillus alvei, b3 = B. mycoides, b4 = P...

  16. Production of Plant Growth-Regulating Substances by the Vesicular-Arbuscular Mycorrhizal Fungus Glomus mosseae

    OpenAIRE

    Barea, José M.; Azcón-Aguilar, Concepción

    1982-01-01

    Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-arbuscular mycorrhiza, was investigated for phytohormone production. Spores of G. mosseae were axenically germinated in water, and the resultant mycelial growth was assayed by standard procedures for extracting plant hormones from microbial cultures. Paper partition chromatography and specific bioassays were used to separate and identify plant growth-regulating substances. The microorganism synthesi...

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

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    Janusz Błaszkowski

    2013-12-01

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

  18. Use of the arbuscular mycorrhizal fungus Glomus intraradices as biological control agent of the nematode Nacobbus aberrans parasitizing tomato

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    Nicolás Marro

    2014-10-01

    Full Text Available The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of "races/groups" with different behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF. In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population of N. aberrans. AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting.

  19. Phosphorus acquisition efficiency in arbuscular mycorrhizal maize is correlated with the abundance of root-external hyphae and the accumulation of transcripts encoding PHT1 phosphate transporters

    Science.gov (United States)

    In light of the rising cost and often limited access to agricultural fertilizers, arbuscular mycorrhizas are attracting ever greater interest for their potential to promote more efficient use of the world's mineral resources. This potential remains largely unrealized, in part because of a lack of un...

  20. Epiparasitic plants specialized on arbuscular mycorrhizal fungi.

    Science.gov (United States)

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

    2002-09-26

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

  1. Effect of simultaneous application of mycorrhiza with compost, vermicompost and sulfural geranole on some quantitative and qualitative characteristics of sesame (Sesamum indicum L. in a low input cropping system

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    P rezvani moghaddam

    2016-03-01

    Full Text Available Introduction In recent years, by increasing human knowledge and using different technology on food production, human concerns have increased on safety of food products especially medicinal crops. In order to achieve healthy food production, application of ecological inputs such as organic and biological fertilizers are inevitable. Organic fertilizers are fertilizer compounds that contain one or more kinds of organic matter. They can improve the soil ability to hold water and nutrients. They create a beneficial environment for earthworms and microbial organisms that break the soil down into rich, fine humus (Motta & Magggiore, 2013. Compost is organic matter that has been decomposed and recycled as a fertilizer and soil amendment. Compost can greatly enhance the physical structure of soil. The addition of compost may provide greater drought resistance and more efficient water utilization. Vermicompost is the final product of composting organic material using different types of worms, such as red wigglers or earthworms, to create a homogenized blend of decomposed vegetable and food waste, bedding materials and manure. Vermicompost helps store nutrients and keeps them safe from leaching and irrigation, functioning to balance hormones within plant physiology, and adding beneficial biology to soil (Raja Sekar & Karmegan, 2010. Mycorrhiza arbuscular fungi are other coexist microorganisms that improves soil fertility, nutrients cycling and agroecosystem health. Mycorrhizal fungi are the most abundant organisms in agricultural soils. Many researchers have pointed to the positive roles of mycorrhizal fungi on plants growth characteristics. Despite of many researches on the effect of organic and biological fertilizers on different crops, information on the effects of these fertilizers for many medicinal plants is scarce, therefore, in this study the effect of simultaneous application of mycorrhiza with compost, vermicompost and sulfural geranole on some

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

    Science.gov (United States)

    Evelin, Heikham; Kapoor, Rupam; Giri, Bhoopander

    2009-01-01

    Background 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. Scope 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. Conclusions 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. PMID:19815570

  3. The role of bacteria and mycorrhiza in plant sulfur supply

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    Jacinta Mariea Gahan

    2014-12-01

    Full Text Available Plant growth is highly dependent on bacteria, saprophytic and mycorrhizal fungi which facilitate the cycling and mobilization of nutrients. Over 95% of the sulfur (S in soil is present in an organic form. Sulfate-esters and sulfonates, the major forms of organo-S in soils, arise through deposition of biological material and are transformed through subsequent humification. Fungi and bacteria release S from sulfate-esters using sulfatases, however, release of S from sulfonates is catalyzed by a bacterial multi-component mono-oxygenase system. The asfA gene is used as a key marker in this desulfonation process to study sulfonatase activity in soil bacteria identified as Variovorax, Polaromonas, Acidovorax and Rhodococcus. The rhizosphere is regarded as a hot spot for microbial activity and recent studies indicate that this is also the case for the mycorrhizosphere where bacteria may attach to the fungal hyphae capable of mobilizing organo-S. While current evidence is not showing sulfatase and sulfonatase activity in arbuscular mycorrhiza, their effect on the expression of plant host sulfate transporters is documented. A revision of the role of bacteria, fungi and the interactions between soil bacteria and mycorrhiza in plant S supply was conducted.

  4. The role of bacteria and mycorrhiza in plant sulfur supply

    Science.gov (United States)

    Gahan, Jacinta; Schmalenberger, Achim

    2014-01-01

    Plant growth is highly dependent on bacteria, saprophytic, and mycorrhizal fungi which facilitate the cycling and mobilization of nutrients. Over 95% of the sulfur (S) in soil is present in an organic form. Sulfate-esters and sulfonates, the major forms of organo-S in soils, arise through deposition of biological material and are transformed through subsequent humification. Fungi and bacteria release S from sulfate-esters using sulfatases, however, release of S from sulfonates is catalyzed by a bacterial multi-component mono-oxygenase system. The asfA gene is used as a key marker in this desulfonation process to study sulfonatase activity in soil bacteria identified as Variovorax, Polaromonas, Acidovorax, and Rhodococcus. The rhizosphere is regarded as a hot spot for microbial activity and recent studies indicate that this is also the case for the mycorrhizosphere where bacteria may attach to the fungal hyphae capable of mobilizing organo-S. While current evidence is not showing sulfatase and sulfonatase activity in arbuscular mycorrhiza, their effect on the expression of plant host sulfate transporters is documented. A revision of the role of bacteria, fungi and the interactions between soil bacteria and mycorrhiza in plant S supply was conducted. PMID:25566295

  5. Occurrence and succession of mycorrhizas in Alnus incana

    Energy Technology Data Exchange (ETDEWEB)

    Arveby, A.S. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Section of Forest Ecophysiology; Granhall, U. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Microbiology

    1998-12-31

    The occurrence of different mycorrhizas of the grey alder, Alnus incana (L.) Moench., in Sweden was investigated. Root sampling was carried out in planted and natural grey alder stands, representing different soil types, geographical sites, and plant ages. Mycorrhizal infection of roots was found to be frequent at all investigated sites, except for some planted peat bogs, where alders do not occur naturally. At the latter sites, mycorrhizal infection was less frequent and consisted only of ectomycorrhizas. Young trees here were non-mycorrhizal. At all other sites vesicular-arbuscular mycorrhiza (VAM) was found to be the almost exclusive type of mycorrhiza in first-year seedlings. In trees older than one year ectomycorrhiza was the dominating type. In the planted stands up to five years of age no fruitbodies of ectomycorrhizal fungi were found. In such stands the ectomycorrhizas generally had thin, translucent mantles and could be observed only by microscopic examination. In one old plantation (27 years) and in the natural stands sporocarps of several specific `alder fungi` were found. Here, the mycorrhizal root tips had thick, mostly whitish mantles. The Hartig net was in all cases confined to penetration between epidermal cells. Soil collected from one alder site and two non-alder biotopes readily infected grey alder seedlings with Frankia and VAM fungi whereas a peat soil failed to infect seedlings with any symbiont. In vitro inoculation of nodulated seedlings with Glomus mossae (Nicol. and Gerd.) Gerdemann and Trappe resulted in VAM-infection. Simultaneous syntheses with isolates of alder-specific, and other, ectomycorrhizal fungi, using three different methods, failed. On the basis of these results an endomycorrhizal-ectomycorrhizal succession after the first growth season in Alnus incana is concluded. A subsequent succession of ectomycorrhizal species from early-stage to late-stage ones is discussed 58 refs, 3 figs, 2 tabs

  6. Does responsiveness to arbuscular mycorrhizal fungi depend on plant invasive status?

    Science.gov (United States)

    Reinhart, Kurt O; Lekberg, Ylva; Klironomos, John; Maherali, Hafiz

    2017-08-01

    Differences in the direction and degree to which invasive alien and native plants are influenced by mycorrhizal associations could indicate a general mechanism of plant invasion, but whether or not such differences exist is unclear. Here, we tested whether mycorrhizal responsiveness varies by plant invasive status while controlling for phylogenetic relatedness among plants with two large grassland datasets. Mycorrhizal responsiveness was measured for 68 taxa from the Northern Plains, and data for 95 taxa from the Central Plains were included. Nineteen percent of taxa from the Northern Plains had greater total biomass with mycorrhizas while 61% of taxa from the Central Plains responded positively. For the Northern Plains taxa, measurable effects often depended on the response variable (i.e., total biomass, shoot biomass, and root mass ratio) suggesting varied resource allocation strategies when roots are colonized by arbuscular mycorrhizal fungi. In both datasets, invasive status was nonrandomly distributed on the phylogeny. Invasive taxa were mainly from two clades, that is, Poaceae and Asteraceae families. In contrast, mycorrhizal responsiveness was randomly distributed over the phylogeny for taxa from the Northern Plains, but nonrandomly distributed for taxa from the Central Plains. After controlling for phylogenetic similarity, we found no evidence that invasive taxa responded differently to mycorrhizas than other taxa. Although it is possible that mycorrhizal responsiveness contributes to invasiveness in particular species, we find no evidence that invasiveness in general is associated with the degree of mycorrhizal responsiveness. However, mycorrhizal responsiveness among species grown under common conditions was highly variable, and more work is needed to determine the causes of this variation.

  7. Predicting plant responses to mycorrhizae: integrating evolutionary history and plant traits.

    Science.gov (United States)

    Reinhart, Kurt O; Wilson, Gail W T; Rinella, Matthew J

    2012-07-01

    We assessed whether (1) arbuscular mycorrhizal colonization of roots (RC) and/or plant responses to arbuscular mycorrhizae (MR) vary with plant phylogeny and (2) MR and RC can be more accurately predicted with a phylogenetic predictor relative to a null model and models with plant trait and taxonomic predictors. In a previous study, MR and RC of 95 grassland species were measured. We constructed a phylogeny for these species and found it explained variation in MR and RC. Next, we used multiple regressions to identify the models that most accurately predicted plant MR. Models including either phylogenetic or phenotypic and taxonomic information similarly improved our ability to predict MR relative to a null model. Our study illustrates the complex evolutionary associations among species and constraints of using phylogenetic information, relative to plant traits, to predict how a plant species will interact with AMF. Published 2012. This article is a US Government work and is in the public domain in the USA.

  8. EFFECTS OF VARIOUS SOIL ENVIRONMENTAL STRESSES ON THE OCCURRENCE, DISTRIBUTION AND EFFECTIVENESS OF VA MYCORRHIZAE

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    A.G. KHAN

    1995-01-01

    Full Text Available The vesicular - arbuscular (VA mycorrhizal fungi are geographically ubiquitous soil inhabitants and form universal symbiotic relationship with plants from every phylum. These fungi link host plants with host soils and their biota in the mycorrhizosphere and play an important role in plant health, productivity and soil structure. Although VA mycorrhizal fungi do not show any host specificity, there is increasing evidence that various climatic and edaphic environmental factors such as land use and management practices, physical, chemical and biological properties of host soils and host plant characteristics influence their occurrence, taxonomic distribution and effectiveness. The interaction of these factors with vesicular-arbuscular mycorrhizae (VAM is poorly understood except in a few cases. It is now very clear that VA mycorrhizal associations are ecologically significant factors that require more attention than previously accorded. This paper discusses the occurrence, distribution and significance of VAM in environmentally stressed soil conditions that limit plant growth such as drought, waterlogging and salinity.

  9. Integrated Control and Assessment of Knapweed and Cheatgrass on Department of Defense Installations. Addendum

    Science.gov (United States)

    2008-02-01

    of an ecosystem. An example is the practice of introducing symbiotic organisms such as mycorrhizae (improvement of plant responses to stress, as...Relationships among nitrogen availability, vesicular-arbuscular mycorrhizae , and Bromus tectorum in disturbed rangeland sites in Colorado. PhD...heathlands. Vegetatio 76:63-69. Allen, M.F., Swenson, W., Querejeta, J. I., Egerton-Warburton, L. M., Treseder, K. K., 2003. Ecology of mycorrhizae

  10. Fractionation of Nitrogen Isotopes by Plants with Different Types of Mycorrhiza in Mountain Tundra Ecosystems

    Science.gov (United States)

    Buzin, Igor; Makarov, Mikhail; Maslov, Mikhail; Tiunov, Alexei

    2017-04-01

    We studied nitrogen concentration and nitrogen isotope composition in plants from four mountain tundra ecosystems in the Khibiny Mountains. The ecosystems consisted of a toposequence beginning with the shrub-lichen heath (SLH) on the ridge and upper slope, followed by the Betula nana dominated shrub heath (SH) on the middle slope, the cereal meadow (CM) on the lower slope and the sedge meadow (SM) at the bottom of the slope. The inorganic nitrogen concentration of the soils from the studied ecosystems were significantly different; the SLH soil was found to contain the minimum concentration of N-NH4+ and N-NO3- , while in the soils of the meadow ecosystems these concentrations were much higher. The concentration of nitrogen in leaves of the dominant plant species in all of the ecosystems is directly connected with the concentration of inorganic nitrogen in the soils, regardless of the plant's mycorrhizal symbiosis type. However, such a correlation is not apparent in the case of plant roots, especially for plant roots with ectomycorrhiza and ericoid mycorrhiza. The majority of plant species with these types of mycorrhiza in the SH and particularly in the CM were enriched in 15N in comparison with the SLH (such plants were not found within the SM). This could be due to several reasons: 1) the decreasing role of mycorrhiza in nitrogen consumption and therefore in the fractionation of isotopes in the relatively-N-enriched ecosystems; 2) the use of relatively-15N-enriched forms of nitrogen for plant nutrition in meadow ecosystems. This heavier nitrogen isotope composition in plant roots with ectomycorrhiza and ericoid mycorrhiza in ecosystems with available nitrogen enriched soils doesn't correspond to the classical idea of mycorrhiza decreasing participation in nitrogen plant nutrition. The analysis of the isotope composition of separate labile forms of nitrogen makes it possible to explain the phenomenon. Not all arbuscular mycorrhizal species within the sedge meadow

  11. Effect of P and Ca on the mycorrhiza of P. sylvestris formation in aseptic condition

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    Elżbieta Chruścik

    2014-08-01

    Full Text Available Ihe effect of some phosphorus and calcium compounds on mycorrhiza formation in pure cultures was investigated. In this experiment — Cenococcum groniforme, Suillus bovinus and Tricholoma albobrunneum were used. The ability to synthese acid phosphatase was tested in 11 strains. The presence of P has a stimulating effect on mycorrhiza formation by S. bovinus und T. albobrunneum. On control medium and medium containing CaO mycorrhiza was absent or only single. Ali strains synthetised phosphatase. The lowest enzymatic activity was found in two C. graniforme strains.

  12. Mycorrhiza and PGPB modulate maize biomass, nutrient uptake and metabolic pathways in maize grown in mining-impacted soil.

    Science.gov (United States)

    Dhawi, Faten; Datta, Rupali; Ramakrishna, Wusirika

    2015-12-01

    Abiotic stress factors including poor nutrient content and heavy metal contamination in soil, can limit plant growth and productivity. The main goal of our study was to evaluate element uptake, biomass and metabolic responses in maize roots growing in mining-impacted soil with the combination of arbuscular mycorrhiza (My) and plant growth promoting bacteria (PGPB/B). Maize plants subjected to PGPB, My and combined treatments showed a significant increase in biomass and uptake of some elements in shoot and root. Metabolite analysis identified 110 compounds that were affected ≥2-fold compared to control, with 69 metabolites upregulated in the My group, 53 metabolites in the My+B group and 47 metabolites in B group. Pathway analysis showed that impact on glyoxylate and dicarboxylate metabolism was common between My and My+B groups, whereas PGPB group showed a unique effect on fatty acid biosynthesis with significant increase in palmitic acid and stearic acid. Differential regulation of some metabolites by mycorrhizal treatment correlated with root biomass while PGPB regulated metabolites correlated with biomass increase in shoot. Overall, the combination of rhizospheric microorganisms used in our study significantly increased maize nutrient uptake and growth relative to control. The changes in metabolic pathways identified during the symbiotic interaction will improve our understanding of mechanisms involved in rhizospheric interactions that are responsible for increased growth and nutrient uptake in crop plants. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus application rates

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    S. Fatih Ergin

    2016-10-01

    Full Text Available In this study, effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus fertilization rates were investigated. Phosphorus were added into growing media as 0, 50, 100 and 200 mg P2O5/kg with and without mycorrhiza applications. Phosphorus applications significantly increased yield criteria of lettuce according to the control treatment statistically. Mycorrhiza application also significantly increased plant diameter, plant dry weight and phosphor uptake by plant. The highest phosphorus uptakes by plants were determined in 200 mg P2O5/kg treatments as 88.8 mg P/pot with mycorrhiza and 83.1 mg P/pot without mycorrhiza application. In the control at 0 doses of phosphorus with mycorrhiza treatment, phosphorus uptake (69.9 mg P/pot, edible weight (84.36 g, dry weight (8.64 g and leaf number (28 of lettuce were higher than that (47.7 mg P/pot, 59.33 g, 6.75 g and 20, respectively in the control without mycorrhiza application. It was determined that mycorrhiza had positive effect on growth criteria and phosphorus nutrition by lettuce plant, and this effect decreased at higher phosphorus application rates.

  14. Fresh perspectives on the roles of arbuscular mycorrhizal fungi in plant nutrition and growth.

    Science.gov (United States)

    Smith, Sally E; Smith, F Andrew

    2012-01-01

    Recent research on arbuscular mycorrhizas has demonstrated that AM fungi play a significant role in plant phosphorus (P) uptake, regardless of whether the plant responds positively to colonization in terms of growth or P content. Here we focus particularly on implications of this finding for consideration of the balance between organic carbon (C) use by the fungi and P delivery (i.e. the C-P trade between the symbionts). Positive growth responses to arbuscular mycorrhizal (AM) colonization are attributed frequently to increased P uptake via the fungus, which results in relief of P deficiency and increased growth. Zero AM responses, compared with non-mycorrhizal (NM) plants, have conventionally been attributed to failure of the fungi to deliver P to the plants. Negative responses, combined with excessive C use, have been attributed to this failure. The fungi were viewed as parasites. Demonstration that the AM pathway of P uptake operates in such plants indicates that direct P uptake by the roots is reduced and that the fungi are not parasites but mutualists because they deliver P as well as using C. We suggest that poor plant growth is the result of P deficiency because AM fungi lower the amount of P taken up directly by roots but the AM uptake of P does compensate for the reduction. The implications of interplay between direct root uptake and AM fungal uptake of P also include increased tolerance of AM plants to toxins such as arsenate and increased success when competing with NM plants. Finally we discuss the new information on C-P trade in the context of control of the symbiosis by the fungus or the plant, including new information (from NM plants) on sugar transport and on the role of sucrose in the signaling network involved in responses of plants to P deprivation.

  15. Contribuição de fungos micorrízicos arbusculares autóctones no crescimento de Guazuma ulmifolia em solo de cerrado degradado Contribution of arbuscular mycorrhizal fungi to the growth of Guazuma ulmifolia in degraded 'cerrado' soil

    Directory of Open Access Journals (Sweden)

    Sueli da Silva Aquino

    2002-12-01

    Full Text Available Ensaios foram conduzidos, em casa de vegetação, com solos de pastagem degradada reflorestada e cerrado preservado (controle visando avaliar a contribuição de fungos micorrízicos arbusculares (FMA autóctones no crescimento de mutambo (Guazuma ulmifolia Lamb.. As mudas foram transplantadas para sacos de plástico (2 kg com substratos esterilizados na proporção 4:1 (solo:areia, e o tratamento inoculado recebeu 300 esporos de FMA por saco. A inoculação não proporcionou aumento significativo na produção da matéria seca da parte aérea, matéria fresca das raízes e altura da planta, sugerindo que a G. ulmifolia não é responsiva à micorrização.Experiments were carried out in a greenhouse, using reforested degraded pasture and preserved 'cerrado' (control soil with the objective to evaluate the contribution of autoctone arbuscular mycorrhizal fungi (AMF on the Guazuma ulmifolia Lamb. growth. Seedlings were transplanted to plastic bags with 2 kg of sterilized soil: sand substrate (4:1. Plants were inoculated with ca. 300 spores of AMF per replication; noninoculated plants served as control. AMF did not improve significantly canopy dry matter, root fresh matter and plant height. G. ulmifolia showed no response to mycorrhizae.

  16. Effect of Phosphate Solubilizing Bacterium, Arbuscular Mycorrhizal Fungus and Chemical Phosphorus Fertilizer on the Yield and Yield Component of Maize (Zea mays L. under Normal and Limited Irrigation Conditions in the Karaj Region

    Directory of Open Access Journals (Sweden)

    M Ghorchiani

    2012-07-01

    Full Text Available In order to evaluate the effect of balanced application of chemical phosphorus fertilizer and seed inoculation with phosphate solubilizing bacterium and arbuscular mycorrhizal fungus and on the yield and yield components of maize (Zea mays L. under normal and limited irrigation conditions, a split-split plots arrangement based on randomized complete block design with three replications was conducted. Treatments consisted of two levels of irrigation including: irrigation of 60 (normal irrigation and 120 (limited irrigation mm evaporation from class A pan evaporation; combination of phosphate solubilizing microorganisms (arbuscular mycorrhiza fungus and phosphate solubilizing bacterium at four levels; and phosphate chemical fertilizer at three levels includes: no consumption of phosphate chemical fertilizer (control, consumption of 50% triple superphosphate fertilizer needed based on soil-test results and consumption of rock phosphate (based on the quantity of consumed phosphate of triple superphosphate source. The results showed that the irrigation levels had significant affect on all traits except harvest index, and the phosphate solubilizing microorganisms had significantly affected all traits except harvest index and number of row in ear. The results of mean comparison indicated that the maximum of amount most traits related to normal irrigation treatment, and co-application of phosphate solubilizing bacterium-arbuscular mycorrhizal fungus. The effect of phosphate chemical fertilizer on all traits was significant. Results of interactions between irrigation and phosphate solubilizing microorganisms in both normal irrigation and limited irrigation conditions showed that the co-application of phosphate solubilizing bacterium-arbuscular mycorrhizal fungus increased grain yield more than other treatments; Also, the result of balanced application of phosphate chemical fertilizer with phosphate solubilizing microorganisms showed that effect of

  17. Production and Application of Arbuscular Mycorrhizal Fungicides%丛枝菌根真菌菌剂的生产及应用概述

    Institute of Scientific and Technical Information of China (English)

    刘静; 刘洁; 金海如

    2012-01-01

    Arbuscular mycorrhizal fungus is a new microbial fertilizer, which plays an irreplaceable role in reduction of chemical fertilizer and pesticide application, reduction of environmental pollution and crop yield improvement. The authors introduce characteristics of arbuscular mycorrhiza fungus and microbial fertilizer types in China, review the production methods and application of arbuscular mycorrhiza fungicides and point out the further application prospect of arbuscular mycorrhiza fungicides.%丛枝菌根真菌(AM真菌)是一种新型的微生物肥料,对减少化肥和农药施用,减少环境污染,提高农作物产量等方面具有不可替代的作用.介绍了AM真菌的特点及我国生产的微生物肥料种类,对AM真菌菌剂的生产方法及其应用情况进行了概述,指出AM真菌菌剂的应用前景.

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

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    Mariusz Tadych

    2014-08-01

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

  19. Rhizobacteria Selection to Enhance Spore Germination and Hyphal Length of Arbuscular Mycorrhizal Fungi in Vitro

    Directory of Open Access Journals (Sweden)

    Cecep Hidayat

    2013-04-01

    Full Text Available In natural condition, Arbuscular Mycorrhizal Fungi (AMF are surrounded by bacteria that help fungi symbiosis. The research aimed to get rhizobacteria that can act as Mycorrhiza Helper Bacteria (MHB had been held at Soil Biology and Biotechnology Laboratory Faculty of Agriculture Unpad from February to March 2012. The experimental design used was completely randomized design with 11 treatments (bo= without rhizobacteria, b1= Pseudomonas diminuta, b2 = Bacillus alvei, b3 = B. mycoides, b4 = P. malei, b5= P. diminuta + B. alvei, b6 = P. diminuta + B. mycoides, b7 = P. diminuta + P. malei, b8 = B. alvei + B. mycoides, b9 = B. alvei + P. malei, b10= B. mycoides + P. malei with 3 replications. Parameters evaluated were spore germination percentage and hyphal length of Glomus sp at 7, 14, 21, and 28 day after planting. The result showed that P. diminuta enhanced spore germination percentage and hyphal length of Glomus spas much as 224 % and 330%respectively than control. So, P. diminuta can be used as MHB.

  20. Effect of arbuscular mycorrhizal fungi on tomato yield and nutrient uptake under different fertilization levels

    Directory of Open Access Journals (Sweden)

    Ľudovít Nedorost

    2012-01-01

    Full Text Available Effect of the arbuscular mycorrhiza on tomato plants (Lycopersicon lycopersicum in the pot experiment was studied. Three different fertilization regimes (optimum – H1, stress a – H2, stress b - H3 and three different mycorrhizal treatments (control – Ctrl, Glomus mossae – Gm, Glomus intraradices – Gi were used. Economical parameter (yield, nutritional characteristic (vitamin C content, phosphates and minerals content, total antioxidant capacity, and level of root colonization were studied. The yield of the tomatoes was influenced by the basic dose of the fertilization, especially in the H2 and H3 treatment. The highest yield was in the H2 treatment in Gm (938 g per plant. The positive effect of the inoculation resulted in the increased content of the vitamin C. The highest significant influence was observed in the H2 treatment (plants inoculated with Gi with the average content of the vitamin C 289 mg.kg−1. The average rate of the colonization was in the range from 39 % to 65 %.

  1. Spider mites adaptively learn recognizing mycorrhiza-induced changes in host plant volatiles.

    Science.gov (United States)

    Patiño-Ruiz, J David; Schausberger, Peter

    2014-12-01

    Symbiotic root micro-organisms such as arbuscular mycorrhizal fungi commonly change morphological, physiological and biochemical traits of their host plants and may thus influence the interaction of aboveground plant parts with herbivores and their natural enemies. While quite a few studies tested the effects of mycorrhiza on life history traits, such as growth, development and reproduction, of aboveground herbivores, information on possible effects of mycorrhiza on host plant choice of herbivores via constitutive and/or induced plant volatiles is lacking. Here we assessed whether symbiosis of the mycorrhizal fungus Glomus mosseae with common bean plants Phaseolus vulgaris influences the response of the two-spotted spider mite Tetranychus urticae to volatiles of plants that were clean or infested with spider mites. Mycorrhiza-naïve and -experienced spider mites, reared on mycorrhizal or non-mycorrhizal bean plants for several days before the experiments, were subjected to Y-tube olfactometer choice tests. Experienced but not naïve spider mites distinguished between constitutive volatiles of clean non-mycorrhizal and mycorrhizal plants, preferring the latter. Neither naïve nor experienced spider mites distinguished between spider mite-induced volatiles of mycorrhizal and non-mycorrhizal plants. Learning the odor of clean mycorrhizal plants, resulting in a subsequent preference for these odors, is adaptive because mycorrhizal plants are more favorable host plants for fitness of the spider mites than are non-mycorrhizal plants.

  2. 丛枝菌根真菌(AMF)对植物群落调节的研究进展%MEDIATIONS OF ARBUSCULAR MYCORRHIZAL FUNGI ON PLANT COMMUNITY

    Institute of Scientific and Technical Information of China (English)

    职桂叶; 陈欣; 唐建军

    2003-01-01

    @@ 1引言 菌根(mycorrhiza)是土壤中的菌根真菌与高等植物营养根系形成的一种共生体,菌根的3个主要的类型(即外生菌根Ectomycorrhiza、内生菌根Endomycorrhiza、内外生菌根Ectendomycorrhiza)中,内生性的丛枝状菌根(Vesicular-Arbuscular mycorrhiza,AM)是分布最广泛、最普遍的一类菌根.

  3. Local and systemic mycorrhiza-induced protection against the ectoparasitic nematode Xiphinema index involves priming of defence gene responses in grapevine

    Science.gov (United States)

    Hao, Zhipeng; Fayolle, Léon; van Tuinen, Diederik; Chatagnier, Odile; Gianinazzi, Silvio; Gianinazzi-Pearson, Vivienne

    2012-01-01

    The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandieri×V. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of mycorrhizal root systems, indicating that both local and systemic induced bioprotection mechanisms were active against the ectoparasitic nematode. Expression analyses of ESTs (expressed sequence tags) generated in an SSH (subtractive suppressive hybridization) library, representing plant genes up-regulated during mycorrhiza-induced control of X. index, and of described grapevine defence genes showed activation of chitinase 1b, pathogenesis-related 10, glutathione S-transferase, stilbene synthase 1, 5-enolpyruvyl shikimate-3-phosphate synthase, and a heat shock proein 70-interacting protein in association with the observed local and/or systemic induced bioprotection against the nematode. Overall, the data suggest priming of grapevine defence responses by the AM fungus and transmission of a plant-mediated signal to non-mycorrhizal tissues. Grapevine gene responses during AM-induced local and systemic bioprotection against X. index point to biological processes that are related either to direct effects on the nematode or to protection against nematode-imposed stress to maintain root tissue integrity. PMID:22407649

  4. Local and systemic mycorrhiza-induced protection against the ectoparasitic nematode Xiphinema index involves priming of defence gene responses in grapevine.

    Science.gov (United States)

    Hao, Zhipeng; Fayolle, Léon; van Tuinen, Diederik; Chatagnier, Odile; Li, Xiaolin; Gianinazzi, Silvio; Gianinazzi-Pearson, Vivienne

    2012-06-01

    The ectoparasitic dagger nematode (Xiphinema index), vector of Grapevine fanleaf virus (GFLV), provokes gall formation and can cause severe damage to the root system of grapevines. Mycorrhiza formation by Glomus (syn. Rhizophagus) intraradices BEG141 reduced both gall formation on roots of the grapevine rootstock SO4 (Vitis berlandieri×V. riparia) and nematode number in the surrounding soil. Suppressive effects increased with time and were greater when the nematode was post-inoculated rather than co-inoculated with the arbuscular mycorrhizal (AM) fungus. Using a split-root system, decreased X. index development was shown in mycorrhizal and non-mycorrhizal parts of mycorrhizal root systems, indicating that both local and systemic induced bioprotection mechanisms were active against the ectoparasitic nematode. Expression analyses of ESTs (expressed sequence tags) generated in an SSH (subtractive suppressive hybridization) library, representing plant genes up-regulated during mycorrhiza-induced control of X. index, and of described grapevine defence genes showed activation of chitinase 1b, pathogenesis-related 10, glutathione S-transferase, stilbene synthase 1, 5-enolpyruvyl shikimate-3-phosphate synthase, and a heat shock proein 70-interacting protein in association with the observed local and/or systemic induced bioprotection against the nematode. Overall, the data suggest priming of grapevine defence responses by the AM fungus and transmission of a plant-mediated signal to non-mycorrhizal tissues. Grapevine gene responses during AM-induced local and systemic bioprotection against X. index point to biological processes that are related either to direct effects on the nematode or to protection against nematode-imposed stress to maintain root tissue integrity.

  5. The effect of potassium and mycorrhiza on growth of vanilla (Vanilla planifolia Andrew

    Directory of Open Access Journals (Sweden)

    I GEDE TIRTA

    2006-04-01

    Full Text Available The few and shallow roots caused slow growth of vanilla seedling. Mycorrhiza may increased the absorption of water and nutrients, while potassium may increased the rate of growth and strength of seedlings. This study was conducted at Sambangan Village, Buleleng, Bali in 2003 (April-Agustus 2003. The experiment was done in polybag and was arranged in Randomized Block Design with three replications. The treatments were consisted of two factors. The first factor was the rates of KCl fertilizer ( 0, 100 and 200 kg ha-1 or 0, 0,10 and 0,20 9 plant-1 and the second factor was the rates of mycorrhiza (0, 20 and 30 g plant-1. The aim of the research to study interactions between potassium and mycorrhiza and The optimum dosage the mycorrhiza on growth of vanilla (Vanilla planifolia Andrew. The resultes showed that there were interactions between potassium and mycorrhiza on fresh weight of the new shoot, root length and fresh root weight. The optimum dosage of the mycorrhiza was 20 g plant-1 with new shoot fresh weight was 25.63 g plant-1. The longest root (24.67 cm plant-1 was observed at the treatment without potasium with 20 g plant-1 mycorrhiza and this was 23% longer than control (19.93 cm plant-1. The highest fresh root weight (2.48 g plant-1 was observed at the dosage of 200 kg KCl ha-1 and 20 g mycorrhiza plant-1 and that was 55% heavier than control (1.60 g plant-1. The leaf number of the plant with 20 g plant-1 mycorrhiza was 6.22 and that was 18% more than control with leaf number 5.25. The total fresh weight of the seedling with 20 g plant-1 mycorrhiza was 86.74 g plant-1or 15% higher compared with control (75.18 g plant-1. The dosage of 100 kg KCl ha-1 increased the K content of the plant (2.45%K or 35% higher than control (1.81%K.

  6. 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.

  7. A Native Arbuscular Mycorrhizal Fungus, Acaulospora scrobiculata Stimulated Growth of Mongolian Crested Wheatgrass ( Agropyron cristatum (L. Gaertn.

    Directory of Open Access Journals (Sweden)

    Burenjargal Otgonsuren

    2010-12-01

    Full Text Available Agr opyron cristatum (L. Gaertn. (crested wheatgrass is an endemic plant species, which dominates most area of the Mongolian steppe and forest steppe. In the present study, spores of arbuscular mycorrhizal fungi in the rhizosphere soil of crested wheatgrass were isolated with wet- sieving/decanting methods, and the major species was identifi ed as Acaulospora scrobiculata Trappe. For arbuscular-mycorrhizal resynthesis, the spores of A. scrobiculata were propagated with corn pot-culture technique and inoculated onto the roots of crested wheatgrass seedlings. The inoculated crested wheatgrass seedlings exhibited vigor in growth, and examination of the root structure revealed the occurrence of arbuscules and vesicles in the cortical cells. These results demonstrated that A. scrobiculata could effectively form arbuscular mycorrhizas with crested wheatgrass and promote its growth, which can be used to restore Mongolian grassland.

  8. Effect of phosphorus 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. Evolutionary conservation of a phosphate transporter in the arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

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

    2004-04-20

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

  10. 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.

  11. Infectivity of soilborne Frankia and mycorrhizae in Discaria trinervis along a vegetation gradient in Patagonian soil.

    Science.gov (United States)

    Chaia, Eugenia Esther; Fontenla, Sonia Beatriz; Vobis, Gernot; Wall, Luis Gabriel

    2006-01-01

    The infective capacities of the nitrogen fixing Actinomycete Frankia and arbuscular mycorrhizal fungi from soils near watercourses, along a vegetation gradient, were studied using plant bioassays. Frankia and arbuscular mycorrhizas capable of infecting Discaria trinervis were found at seventeen sites sampled. More specific enumeration of the infective capacities of both microorganisms in relation to environmental factors was performed in seven representative soils of the analysed vegetation zones (rainforest, xeric forest and steppe) using the most probable number method. The highest nodulation capacities ranged from 340 infective units g(-1 )soil, in a steppe marsh devoid of actinorhizas, to 61 in a coastal actinorhizal scrub (in xeric forest). The highest number of infective mycorrhizal units--also found in marsh--was 145. In general, rainforest soils had the lowest values for both microorganisms. Infective units of Frankia and arbuscular mycorrhizal fungi in soil were positively correlated (r = 0.89, P < 0.05). Both soilborne symbionts showed the highest infective capacity in semi-arid conditions nearby watercourse and at the valley bottom location. Tripartite symbiosis was effective in plants inoculated with steppe and xeric forest soils and plants inoculated with Frankia BCU110501 and Glomus mosseae. Interaction between both symbionts and influence of environmental conditions, in general, would contribute to define comparable trends of their infective capacities. ((c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

  12. [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.

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

    Science.gov (United States)

    Merckx, Vincent; Bidartondo, Martin I

    2008-05-01

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

  14. Molecular community analysis of arbuscular mycorrhizal fungi in roots of geothermal soils in Yellowstone National Park (USA).

    Science.gov (United States)

    Appoloni, Susann; Lekberg, Ylva; Tercek, Michael T; Zabinski, Catherine A; Redecker, Dirk

    2008-11-01

    To better understand adaptation of plants and their mycorrhizae to extreme environmental conditions, we analyzed the composition of communities of arbuscular mycorrhizal fungi (AMF) in roots from geothermal sites in Yellowstone National Park (YNP), USA. Arbuscular mycorrhizal fungi were identified using molecular methods including seven specific primer pairs for regions of the ribosomal DNA that amplify different subgroups of AMF. Roots of Dichanthelium lanuginosum, a grass only occurring in geothermal areas, were sampled along with thermal and nonthermal Agrostis scabra and control plants growing outside the thermally influenced sites. In addition, root samples of Agrostis stolonifera from geothermal areas of Iceland were analyzed to identify possible common mycosymbionts between these geographically isolated locations. In YNP, 16 ribosomal DNA phylotypes belonging to the genera Archaeospora, Glomus, Paraglomus, Scutellospora, and Acaulospora were detected. Eight of these phylotypes could be assigned to known morphospecies, two others have been reported previously in molecular studies from different environments, and six were new to science. The most diverse and abundant lineage was Glomus group A, with the most frequent phylotype corresponding to Glomus intraradices. Five of the seven phylotypes detected in a preliminary sampling in a geothermal area in Iceland were also found in YNP. Nonthermal vegetation was dominated by a high diversity of Glomus group A phylotypes while nonthermal plants were not. Using multivariate analyses, a subset of three phylotypes were determined to be associated with geothermal conditions in the field sites analyzed. In conclusion, AMF communities in geothermal soils are distinct in their composition, including both unique phylotypes and generalist fungi that occur across a broad range of environmental conditions.

  15. Amazonian açai and food dyes for staining arbuscular- micorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Aline Lourdes Martins Silva

    2015-12-01

    Full Text Available Arbuscular mycorrhizae microscopy requires differential staining of typical structures. Dyes employed, such as trypan blue, pose risks to health and environment. Alternative dyes such as pen ink and aniline have variable coloring efficiency. In this work, Brachiaria decumbens roots, discolored with caustic soda (NaOH, were stained with açai, annatto, saffron, trypan blue and pen inks. There were significant differences among dyes regarding stained mycorrhizal structures and pictures quality. Acai was considered the best alternative dye, with similar results to trypan blue.

  16. 丛枝菌根真菌分类最新进展%Latest Advances in the Classification of Arbuscular Mycorrhizal Fungi

    Institute of Scientific and Technical Information of China (English)

    王发园; 林先贵; 周健民

    2005-01-01

    近 10 a来,随着分子生物学技术在丛枝菌根(arbuscular mycorrhiza,AM)研究中的应用,AM真菌分类学得到迅速发展.重点介绍AM真菌的最新分类系统,并对其发展简史作一简单回顾.

  17. 黄河三角洲盐碱地的丛枝菌根真菌%ARBUSCULAR MYCORRHIZAL FUNGI IN SALINE-ALKALINE SOILS OF YELLOW RIVER DELTA

    Institute of Scientific and Technical Information of China (English)

    王发园; 刘润进

    2002-01-01

    作者调查了黄河三角洲盐碱地丛枝菌根(Arbuscular mycorrhizae, AM)真菌的资源状况.共分离鉴定出Acaulospora属6种, Archaespora属2种, Glomus 属24种, 其中G. melanosporum, G. pansihalos, G. pustulatum, G. tenebrosum等4种为我国的新记录种.

  18. 尖峰岭地区龙脑香科植物根围的AM真菌%ARBUSCULAR MYCORRHIZAL FUNGI OF DIPTEROCARPACEAE IN JIANFENGLING MOUNTAIN, HAINAN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    石兆勇; 陈应龙; 刘润进

    2003-01-01

    调查了海南岛尖峰岭13种龙脑香科植物根围的丛枝菌根(Arbuscular mycorrhizae, AM)真菌的资源状况.共分离鉴定出Acaulospora属4种, Glomus 属16种, Scutellospora属3种, 其中Scutellospora nigra (Redhead) Walker & Sanders为我国的新记录种.

  19. 西双版纳地区龙脑香科植物根围的AM真菌%ARBUSCULAR MYCORRHIZAL FUNGI OF DIPTEROCARPACEAE IN XISHUANGBANNA, SOUTHERN YUNNAN

    Institute of Scientific and Technical Information of China (English)

    石兆勇; 陈应龙; 刘润进

    2003-01-01

    调查了版纳地区龙脑香科植物根围的丛枝菌根(Arbuscular mycorrhizae,AM)真菌的资源状况.共分离鉴定出Acaulospora属9种,Archaeospora属2种,Glomus属23种,Paraglomus属1种,Scutellospora属2种,其中Acaulospora rehmii,Glomus convolutum,Glomus magnicaule 3种为我国的新记录种.

  20. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    Science.gov (United States)

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production.

  1. Response of Root Properties to Tripartite Symbiosis between Lucerne (Medicago sativa L., Rhizobia and Mycorrhiza Under Dry Organic Farming Conditions

    Directory of Open Access Journals (Sweden)

    M. R. Ardakani

    2009-01-01

    Full Text Available Problem statement: It is generally considered that root turnover is a major contributor to organic matter and mineral nutrient cycles in organic managed agroecosystems. Approach: This study designed to investigate whether microbial activity could affect on root properties of Lucerne in an organically managed field under dry weather conditions. The trial was laid out as a factorial experiment in the fields of the University of Natural Resources and Applied Life Sciences, Vienna- Austria at Raasdorf in 2007. The experimental factors of Rhizobium (Sinorhizobium meliloti and Arbuscular Mycorrhiza (AM including Glomus etunicatum, G. intraradices and G. claroideum and irrigation levels were tested. Results: Results showed that increasing water deficit affected root dry weigh, specific root mass and root length significantly at 1% level and co-inoculation of rhizobium and mycorrhiza with irrigation increased all root parameters. Datas of variance analysis for mycorrhizal colonization showed that main effect of using mycorrhiza had significant effects on root parameters at 5 and 1% probability level at first and second harvest, respectively. Results of mean comparisons by Duncans Multiple Range Test showed that mycorrhizal colonization was higher in the inoculated treatments by rhizobium, mycorrhiza and irrigated plots in both harvests. Double interaction of mycorrhiza and irrigation was higher in both harvests (37.05 and 65.73%, respectively. Conclusion: It can be suggested that the tripartite symbiosis of Rhizobium, AM and Lucerne can improve the performance of Lucerne in organic farming and under dry conditions. Such traits could be incorporated into breeding programs to improve drought tolerance especially in organic fields.

  2. Interaction between C 4 barnyard grass and C 3 upland rice under elevated CO 2: Impact of mycorrhizae

    Science.gov (United States)

    Tang, Jianjun; Xu, Liming; Chen, Xin; Hu, Shuijin

    2009-03-01

    Atmospheric CO 2 enrichment may impact arbuscular mycorrhizae (AM) development and function, which could have subsequent effects on host plant species interactions by differentially affecting plant nutrient acquisition. However, direct evidence illustrating this scenario is limited. We examined how elevated CO 2 affects plant growth and whether mycorrhizae mediate interactions between C 4 barnyard grass ( Echinochloa crusgalli (L.) Beauv.) and C 3 upland rice ( Oryza sativa L.) in a low nutrient soil. The monocultures and combinations with or without mycorrhizal inoculation were grown at ambient (400 ± 20 μmol mol -1) and elevated CO 2 (700 ± 20 μmol mol -1) levels. The 15N isotope tracer was introduced to quantify the mycorrhizally mediated N acquisition of plants. Elevated CO 2 stimulated the growth of C 3 upland rice but not that of C 4 barnyard grass under monoculture. Elevated CO 2 also increased mycorrhizal colonization of C 4 barnyard grass but did not affect mycorrhizal colonization of C 3 upland rice. Mycorrhizal inoculation increased the shoot biomass ratio of C 4 barnyard grass to C 3 upland rice under both CO 2 concentrations but had a greater impact under the elevated than ambient CO 2 level. Mycorrhizae decreased relative interaction index (RII) of C 3 plants under both ambient and elevated CO 2, but mycorrhizae increased RII of C 4 plants only under elevated CO 2. Elevated CO 2 and mycorrhizal inoculation enhanced 15N and total N and P uptake of C 4 barnyard grass in mixture but had no effects on N and P acquisition of C 3 upland rice, thus altering the distribution of N and P between the species in mixture. These results implied that CO 2 stimulation of mycorrhizae and their nutrient acquisition may impact competitive interaction of C 4 barnyard grass and C 3 upland rice under future CO 2 scenarios.

  3. 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.

  4. [Effects of the arbuscular mycorrhizal fungi on environmental phytoremediation in coal mine areas].

    Science.gov (United States)

    Li, Shao-Peng; Bi, Yin-Li; Kong, Wei-Ping; Wang, Jin; Yu, Hai-Yang

    2013-11-01

    To resolve the key environmental problems in coal mine areas of environmental phytoremediation, symbiosis of arbuscular mycorrhizal fungi (AMF) and Amorpha fruticosa was investigated. Effects of AMF on the root growth of Amorpha fruticosa and degenerated soil in coal mining subsidence area were studied. Results showed that after 5 months inoculation, AMF improved the shoot and root growth of Amorpha fruticosa. After inoculation with arbuscular mycorrhiza (AM) for 5 months, the inoculation significantly increased root colonization of Amorpha fruticosa. Total glomalin and easily extractable glomalin were increased significantly in the incubated soil. The content of phosphorus and organic matter were increased in the rhizosphere soil. Population of microorganism increased obviously. All the above results show that their ecological effects are significantly improved. AM would promote rhizosphere soil that will help the sustainability of ecological systems in mining area. It is really of great significance to keep the ecological system stability.

  5. Transfer of N and P from intact or decomposing roots of pea to barley interconnected by an arbuscular mycorrhizal fungus

    DEFF Research Database (Denmark)

    Johansen, A.; Jensen, E.S.

    1996-01-01

    The role of arbuscular mycorrhizas in the transfer of N and P between pea (Pisum sativum L.) and barley (Hordeum vulgare L.) plants was studied in a controlled environment. The plants were grown together in PVC containers, either in symbiosis with Glomus intraradices Schenck and Smith or as non......-mycorrhizal controls, and with their root systems separated by an intermediate buffer zone (2 cm), confined by fine nylon mesh. The pea donor plants were supplied simultaneously with N-15 and P-32, using a split-root labelling technique, in order to follow the flow of N and P to the barley receiver plants during 60 d...... of growth. In half of the containers, the donor-plant shoot was removed 42 d after the start of labelling and the roots were left in the soil to decompose. The reverse transfer of N and P, from barley donor to pea receiver plants was also measured to allow calculation of the net transfer through hyphae...

  6. The mycorrhiza helper bacteria revisited.

    Science.gov (United States)

    Frey-Klett, P; Garbaye, J; Tarkka, M

    2007-01-01

    In natural conditions, mycorrhizal fungi are surrounded by complex microbial communities, which modulate the mycorrhizal symbiosis. Here, the focus is on the so-called mycorrhiza helper bacteria (MHB). This concept is revisited, and the distinction is made between the helper bacteria, which assist mycorrhiza formation, and those that interact positively with the functioning of the symbiosis. After considering some examples of MHB from the literature, the ecological and evolutionary implications of the relationships of MHB with mycorrhizal fungi are discussed. The question of the specificity of the MHB effect is addressed, and an assessment is made of progress in understanding the mechanisms of the MHB effect, which has been made possible through the development of genomics. Finally, clear evidence is presented suggesting that some MHB promote the functioning of the mycorrhizal symbiosis. This is illustrated for three critical functions of practical significance: nutrient mobilization from soil minerals, fixation of atmospheric nitrogen, and protection of plants against root pathogens. The review concludes with discussion of future research priorities regarding the potentially very fruitful concept of MHB.

  7. Interactions between arbuscular mycorrhizal fungi and soil bacteria.

    Science.gov (United States)

    Miransari, Mohammad

    2011-02-01

    The soil environment is interesting and complicated. There are so many interactions taking place in the soil, which determine the properties of soil as a medium for the growth and activities of plants and soil microorganisms. The soil fungi, arbuscular mycorrhiza (AM), are in mutual and beneficial symbiosis with most of the terrestrial plants. AM fungi are continuously interactive with a wide range of soil microorganisms including nonbacterial soil microorganisms, plant growth promoting rhizobacteria, mycorrhiza helper bacteria and deleterious bacteria. Their interactions can have important implications in agriculture. There are some interesting interactions between the AM fungi and soil bacteria including the binding of soil bacteria to the fungal spore, the injection of molecules by bacteria into the fungal spore, the production of volatiles by bacteria and the degradation of fungal cellular wall. Such mechanisms can affect the expression of genes in AM fungi and hence their performance and ecosystem productivity. Hence, consideration of such interactive behavior is of significance. In this review, some of the most important findings regarding the interactions between AM fungi and soil bacteria with some new insights for future research are presented.

  8. Effects of mycorrhiza inoculation and different irrigation levels on yield, yield components and essential oil contents of fennel (Foeniculum vulgare Mill. and ajwain (Trachyspermum ammi L.

    Directory of Open Access Journals (Sweden)

    A Koocheki

    2016-05-01

    Full Text Available Introduction Fertilizers are the key components which provide plant nutrients' needs in recent years (Omid Jangir & Sing, 1996; Kapoor et al., 2007. In many cases, using chemical fertilizers has different negative environmental effects such as soil, water and air pollution, which increase environmental hazardous and production costs (Jangir & Sing, 1996; Kapoor et al., 2007. Biological activities are markedly enhanced by microbial interactions in the rhizosphere of plants (Kapoor et al., 2007. Many investigators have successfully used mycorrhiza to increase the availability of immobilized phosphate and thus minimize the use of mineral fertilizers. Arbuscular Mycorrhizal Fungi (AMF can better enable a plant to withstand environmental stresses such as drought and salinity. AMF interacts with pathogens and other rhizosphere inhabitants which affect plant health and nutrition. More importantly, mycorrhizal fungi are capable of dissolving weakly soluble soil minerals, especially phosphate, by releasing acids or increasing CO2 partial pressure (Gupta et al., 2002; Gosling et al., 2006; Kapoor et al., 2007. Therefore, they have the ability to enhance host plant uptake of relatively immobile nutrients particularly P, S and Zn. Limited water supply is also another major environmental constraint in the productivity of crop and medicinal plants. Moisture deficiency induces various physiological and metabolic responses such as stomatal closure, decline in growth rate and photosynthesis (Flexas and Medrano, 2002. The results of Baher et al. (2002 showed that greater soil water stress decreased plant height and total fresh and dry weight of Satureja hortensis. Materials and Methods In order to study the effects of mycorrhiza inoculation and different irrigation levels on the growth, quantitative and qualitative yield of fennel (Foeniculum vulgare Mill. and ajwain (Trachyspermum ammi L., a field experiment was conducted as factorial based on randomized

  9. Enhanced Tomato Disease Resistance Primed by Arbuscular Mycorrhizal Fungus

    Directory of Open Access Journals (Sweden)

    Yuanyuan eSong

    2015-09-01

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

  10. Enhanced tomato disease resistance primed by arbuscular mycorrhizal fungus

    Science.gov (United States)

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

    2015-01-01

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

  11. The characterization of novel mycorrhiza-specific phosphate transporters from ¤Lycopersicon esculentum¤ and ¤Solanum tuberosum¤ uncovers functional redundancy in symbiotic phosphate transport in solanaceous species

    DEFF Research Database (Denmark)

    Nagy, F.; Karandashov, V.; Chague, W.

    2005-01-01

    Solanaceous species are among the >200 000 plant species worldwide forming a mycorrhiza, that is, a root living in symbiosis with soil-borne arbuscular-mycorrhizal (AM) fungi. An important parameter of this symbiosis, which is vital for ecosystem productivity, agriculture, and horticulture......, is the transfer of phosphate (Pi) from the AM fungus to the plant, facilitated by plasma membrane-spanning Pi transporter proteins. The first mycorrhiza-specific plant Pi transporter to be identified, was StPT3 from potato [Nature 414 (2004) 462]. Here, we describe novel Pi transporters from the solanaceous...... species tomato, LePT4, and its orthologue StPT4 from potato, both being members of the Pht1 family of plant Pi transporters. Phylogenetic tree analysis demonstrates clustering of both LePT4 and StPT4 with the mycorrhiza-specific Pi transporter from Medicago truncatula [Plant Cell, 14 (2002) 2413] and rice...

  12. Mycorrhiza: A Common Form of Mutualism.

    Science.gov (United States)

    Medve, Richard J.

    1978-01-01

    Mycorrhizae are among the most common examples of mutualism. This article discusses their structure, symbolic relationship, factors affecting formation and applying research. Questions are posed and answers suggested. (MA)

  13. Mycorrhiza: A Common Form of Mutualism.

    Science.gov (United States)

    Medve, Richard J.

    1978-01-01

    Mycorrhizae are among the most common examples of mutualism. This article discusses their structure, symbolic relationship, factors affecting formation and applying research. Questions are posed and answers suggested. (MA)

  14. Influencia de diferentes especies de fungo micorrizico arbuscular no desenvolvimento do crisântemo Influence of different species of arbuscular mycorrhizal fungi on chrysanthemum growth

    Directory of Open Access Journals (Sweden)

    Adriana Parada Dias da Silveira

    1996-01-01

    Full Text Available Com o objetivo de verificar o desenvolvimento e florescimento do crisântemo (Dendranthema grandiflora na presença de micorriza arbuscular, foi instalado, em casa de vegetação, um experimento, empregando-se os fungos Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama. Utilizou-se terra roxa estruturada, da Série Luiz de Queiroz, esterilizada (por autoclavagem e não esterilizada. No florescimento, colheram-se as plantas e determinaram-se a altura, a matéria seca da parte aérea, a matéria fresca da raiz, o teor de P e K na parte aérea, a colonização micorrízica e o número de esporos do fungo micorrízico. O desenvolvimento e o florescimento foram favorecidos pela inoculação de G. leptotichum e G.macrocarpum, quando as plantas foram cultivadas em solo esterilizado, superando o efeito dos fungos micorrízicos nativos. Entretanto, no solo não esterilizado, a inoculação dessas espécies de fungo não promoveu aumento no desenvolvimento da planta.A greenhouse experiment was conducted to verify the effect of arbuscular mycorrhiza on growth and flowering of chrysanthemum. Rooted plants were inoculated with Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama or non-inoculated. Plants were grown in a autoclave sterilized, and non-sterilized soil of the type "Terra Roxa Estruturada". At the flowering stage, plants were harvested and measured for plant height, shoot dry matter, root fresh matter, shoot P and K content, mycorrhizal root colonization and number of mycorrhizal fungi spores. Plants colonized with G.leptotichum and G. macrocarpum presented higher growth and flowering than control plants, in sterilized soil, overcoming the effect of native mycorrhizal fungi. However, there was no effect of introduced mycorrhizal fungi on non-sterilized soil.

  15. 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.

  16. Reduced arbuscular mycorrhizal colonization in tomato ethylene mutants Reduzida formação de micorrízas arbusculares em tomateiros mutantes em etileno

    Directory of Open Access Journals (Sweden)

    Agustin Zsögön

    2008-01-01

    Full Text Available Plant hormones are likely key regulators of arbuscular mycorrhizae (AM development. However, their roles in AM are not well known. Here mutants in five hormone classes introgressed in a single tomato (Lycopersicon esculentum Mill. Syn Solanum lycopersicum L. background (cv. Micro-Tom were used to determine their effects on AM development and the expression of defense-related genes (chitinases and b-1,3-glucanases in roots. Under low P conditions, mutant epinastic (epi and Never ripe (Nr, ethylene overproducer and low sensitivity, respectively, had the intraradical colonization by Glomus clarum highly inhibited, as compared to the control Micro-Tom (MT. No significant alterations in fungal colonization were observed in mutants affecting other hormone classes. Under low P conditions, the steady state levels of transcripts encoding a class I basic chitinase (chi9 were higher in mycorrhizal epi and Nr mutant roots as compared to MT controls. In contrast the steady state levels of a class III acidic b-1,3-glucanase (TomPR-Q'a transcripts in mycorrhizal epi mutant roots were significantly lower than in mycorrhizal MT roots. Root colonization in epi mutants was accompanied by several alterations in fungal morphology, as compared to root colonization in MT controls. The data suggest that ethylene may play an important role in controlling intraradical arbuscular mycorrhizal fungal growth.Os hormônios vegetais são possíveis reguladores chave do desenvolvimento de micorrizas arbusculares (MAS. Contudo, seus papéis em MA são pouco conhecidos. No presente estudo, foram utilizados mutantes em cinco classes hormonais introgredidos em uma única cultivar (cv. Micro-Tom de tomateiro (Lycopersicon esculentum Mill. Syn Solanum lycopersicum L. para determinar seus efeitos no desenvolvimento de MA e expressão de genes relacionados à defesa (quitinases e b-1,3-glucanases em raízes. Sob condição de baixo P, os mutantes epinastic (epi e Never ripe (Nr, os

  17. Arbuscular mycorrhizal and dark septate endophyte associations of medicinal plants

    Directory of Open Access Journals (Sweden)

    Szymon Zubek

    2011-10-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF and dark septate endophyte (DSE associations were studied in 36 medicinal plant species from 33 genera and 17 families, collected from the Botanical Garden of the Jagiellonian University in Kraków. Arbuscular mycorrhiza (AM was found in 34 species (94%; 26 were of the Arum-type, 4 – Paris and 4 taxa revealed intermediate morpho­logy. The abundance of AMF hyphae in roots varied with particular species, ranging from 2.5% (Helianthus tuberosus to 77.9% (Convallaria majalis. The mycelium of DSE was observed in 13 plant species (36%, however, the percentage of root colonization by these fungi was low. Spores of 7 AMF species (Glomeromycota were isolated from trap cultures established from rhizosphere soils of the investigated plants: Archaeospora trappei (Archaeosporaceae, Glomus aureum, Glomus caledonium, Glomus claroideum, Glomus constrictum, Glomus mosseae, Glomus versiforme (Glomeraceae. Our results are the first detailed report of root endophyte associations of the plant species under study. Moreover, the mycorrhizal status of 14 plant species is reported for the first time.

  18. Mycorrhiza-induced resistance: more than the sum of its parts?

    Science.gov (United States)

    Cameron, Duncan D.; Neal, Andrew L.; van Wees, Saskia C.M.; Ton, Jurriaan

    2014-01-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This ‘mycorrhiza-induced resistance’ (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely responsible for MIR. In this opinion article, we present a novel model of MIR that integrates different aspects of the induced resistance phenomenon. We propose that MIR is a cumulative effect of direct plant responses to mycorrhizal infection and indirect immune responses to ISR-eliciting rhizobacteria in the mycorrhizosphere. PMID:23871659

  19. Mycorrhiza-induced resistance: more than the sum of its parts?

    Science.gov (United States)

    Cameron, Duncan D; Neal, Andrew L; van Wees, Saskia C M; Ton, Jurriaan

    2013-10-01

    Plants can develop an enhanced defensive capacity in response to infection by arbuscular mycorrhizal fungi (AMF). This 'mycorrhiza-induced resistance' (MIR) provides systemic protection against a wide range of attackers and shares characteristics with systemic acquired resistance (SAR) after pathogen infection and induced systemic resistance (ISR) following root colonisation by non-pathogenic rhizobacteria. It is commonly assumed that fungal stimulation of the plant immune system is solely responsible for MIR. In this opinion article, we present a novel model of MIR that integrates different aspects of the induced resistance phenomenon. We propose that MIR is a cumulative effect of direct plant responses to mycorrhizal infection and indirect immune responses to ISR-eliciting rhizobacteria in the mycorrhizosphere.

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

    Science.gov (United States)

    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(-1)soil. 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.

  1. Symbiosis-related pea genes modulate fungal and plant gene expression during the arbuscule stage of mycorrhiza with Glomus intraradices.

    Science.gov (United States)

    Kuznetsova, Elena; Seddas-Dozolme, Pascale M A; Arnould, Christine; Tollot, Marie; van Tuinen, Diederik; Borisov, Alexey; Gianinazzi, Silvio; Gianinazzi-Pearson, Vivienne

    2010-08-01

    The arbuscular mycorrhiza association results from a successful interaction between genomes of the plant and fungal symbiotic partners. In this study, we analyzed the effect of inactivation of late-stage symbiosis-related pea genes on symbiosis-associated fungal and plant molecular responses in order to gain insight into their role in the functional mycorrhizal association. The expression of a subset of ten fungal and eight plant genes, previously reported to be activated during mycorrhiza development, was compared in Glomus intraradices-inoculated wild-type and isogenic genotypes of pea mutated for the PsSym36, PsSym33, and PsSym40 genes where arbuscule formation is inhibited or fungal turnover modulated, respectively. Microdissection was used to corroborate arbuscule-related fungal gene expression. Molecular responses varied between pea genotypes and with fungal development. Most of the fungal genes were downregulated when arbuscule formation was defective, and several were upregulated with more rapid fungal development. Some of the plant genes were also affected by inactivation of the PsSym36, PsSym33, and PsSym40 loci, but in a more time-dependent way during root colonization by G. intraradices. Results indicate a role of the late-stage symbiosis-related pea genes not only in mycorrhiza development but also in the symbiotic functioning of arbuscule-containing cells.

  2. Effects of Mycorrhizae on Carbon Cycling in Response to Extreme Drought

    Science.gov (United States)

    Ficken, C. D.; Warren, J.

    2016-12-01

    Plant-mycorrhizal symbioses are being increasingly accepted as drivers of ecosystem-level biogeochemical patterns and play an important role plant resource acquisition. Although some evidence suggests that mycorrhizal association increases plant drought-tolerance, direct comparisons of drought-resilience between mycorrhizal groups (i.e. arbuscular and ectomycorrhizal) are lacking. Indeed, soil CO2 pulses following dry-wet cycles are detectable at the ecosystem scale, but it remains unclear whether these pulses are driven by the activity of mycorrhizae or free-living microbes. These knowledge gaps hinder our ability to predict CO2 fluxes in the face of increased precipitation variability and have broad implications for understanding plant performance during, and recovery following, drought. We predicted that arbuscular mycorrhizae (AM) would be more resilient to drought than ectomycorrhizae (ECM) because narrower AM hyphae may access water from smaller soil pores and because AM produce a glycoprotein that increases soil aggregation. To compare the functioning of AM and ECM throughout drought, we examined soil respiration dynamics between AM- and ECM-dominated mesocosms throughout moderate and extreme drought. Mesocosms were partitioned with mesh dividers into chambers (roots+hyphae+microbes; hyphae+microbes; microbes only) to compare the relative functioning of biotic pools throughout drought. We found that respiration responses to drought differed substantially between AM and ECM-dominated systems. Under dry conditions, respiration from both root- and hyphal-exclusion chambers did not differ between AM and ECM mesocosms. In contrast, under wet conditions, respiration was significantly greater from AM than ECM mesocosms. Following rewetting, the respiration pulse in AM systems was largely due to to free-living microbes (+330% C flux above dry conditions), whereas in ECM systems there was a proportionally greater increase from mycorrhizal chambers (+130%). This

  3. Synergism Among VA Mycorrhiza, Phosphate Solubilizing Bacteria and Rhizobium for Symbiosis with Blackgram (Vigna mungo L.) UnderField Conditions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A field experiment was conducted at the G.B. Pant University Research Station, Ujhani (U.P.) in rainy (Kharif) season of the year 1994-1995 to study the effect of Rhizobium, VAM (vesicular arbuscular mycorrhiza) and PSB (phosphate solubilizing bacteria) inoculation, with and without P, on blackgram (Vigna mungo L.) seed yield. Phosphorus application in soil with medium P content (5.4 mg kg1) increased nodulation, grain yield, N and P in plant and grain over no phosphorus control. Forty kilograms of P2O5 each hactare recorded an increase of 20.6 % in nodule dry weight, significant increases of 0.35 g kg-1 in N concentration and 1.28 g kg-1 in P concentration of plant over 20 kg P2O5 ha-1. Similar significant increases of 0.59 g kg-1 in grain yield and 0.54 and 0.23 g kg-1 in N and P concentrations of the grain, respectively, over 20 kg P2O5 ha-1 were also obtained with higher dose. Inoculation of Rhizobium + VAM + PSB at all the stages of plant growth recorded maximum increases in all the parameters studied. Dual inoculation of Rhizobium with either VAM or PSB was generally significant in the effect and better than that of VAM + PSB, however, P accumulation in plant and grain was more with VAM + PSB. Among single inoculations, Rhizobium gave highest and 21.0 % more nodule number, 34.7 % more nodule dry mass, 0.73 g kg-1 more N in grain and 4.2 % higher grain yield over PSB. PSB, however, registered significant increases in P concentration in plant and grain over VAM and Rhizobium.

  4. Root foraging for Patchy Phosphorus of Plant Species with Contrasting Foraging Strategy - Role of Roots and Mycorrhiza

    Science.gov (United States)

    Felderer, B.; Robinson, B. H.; Jansa, J.; Vontobel, P.; Frossard, E.; Schulin, R.

    2009-04-01

    three species of arbuscular mycorrhizal fungi (AMF; Glomus intraradices, Glomus claroideum, Gigaspora margarita). Therefore, we will conduct a mesocosm experiment in a 2 x 2 x 5 factorial design, with two plant species, two P distribution patterns (homogeneous, heterogeneous) and five mycorrhizal treatments (three sterilized treatments inoculated with different AMF species, one sterilized inoculated control, one non-sterilized control). We will apply Neutron Radiography (NR)-technique to investigate root architecture on a time line. NR is a non-invasive technique that can be applied to image roots in sand or soil. In the soil-root system, neutrons are mainly retained or scattered by hydrogen. Because of the higher water content, roots appear darker on the image than the surrounding sand/soil. At the end of the experiment, above and belowground biomass will be harvested and P concentrations will be determined. Roots within and outside nutrient-rich patches will be sampled separately. Root architecture will be determined with WinRhizo. We will apply dual radioisotopic labeling of the soil P to investigate physiological plasticity of the roots and/or plant-mycorrhizal association with respect to the P uptake. Ten days before the end of the experiment we will inject carrier-free 32P-orthophosphate solution to the P-rich patch and 33P to the substrate outside the patch. At harvest, we will measure 32P and 33P availabilities in the substrate and the radioisotope contents in plants, and calculate P uptake per unit of root surface within and outside the P-rich patch. We will use real-time polymerase chain reaction assay targeting the species-specific motifs in the ribosomal large subunit to assess abundances of the different AMF species within the roots and in the soil enriched or not with P (i.e. plasticity of mycorrhiza-plant association).

  5. Giving and receiving: measuring the carbon cost of mycorrhizas in the green orchid, Goodyera repens.

    Science.gov (United States)

    Cameron, Duncan D; Johnson, Irene; Read, David J; Leake, Jonathan R

    2008-01-01

    Direct measurement of the carbon (C) 'cost' of mycorrhizas is problematic. Although estimates have been made for arbuscular and ectomycorrhizal symbioses, these are based on incomplete budgets or indirect measurements. Furthermore, the conventional model of unidirectional plant-to-fungus C flux is too simplistic. Net fungus-to-plant C transfer supports seedling establishment in c. 10% of plant species, including most orchids, and bidirectional C flows occur in ectomycorrhiza utilizing soil amino acids. Here, the C cost of mycorrhizas to the green orchid Goodyera repens was determined by measurement of simultaneous bidirectional fluxes of 14C labelled sources using a monoxenic system with the fungus Ceratobasidium cornigerum. Transfer of C from fungus to plant ('up-flow') occurs in the photosynthesizing orchid G. repens (max. 0.06 microg) whereas over five times more current assimilate (min. 0.355 microg) is simultaneously allocated in the reverse direction to the mycorrhizal fungus ('down-flow') after 8 d. Carbon is transferred rapidly, being detected in plant-fungal respiration within 31 h of labelling. This study provides the most complete C budget for an orchid-mycorrhizal symbiosis, and clearly shows net plant-to-fungus C flux. The rapidity of bidirectional C flux is indicative of dynamic transfer at an interfacial apoplast as opposed to reliance on digestion of fungal pelotons.

  6. Remote Sensing of Mycorrhizae? Detection of Mycorrhizal Association from Canopy Spectral Properties.

    Science.gov (United States)

    Fisher, J. B.; Sweeney, S.; Brzostek, E. R.; Evans, T. P.; Bourg, N. A.; Phillips, R.

    2014-12-01

    Nearly all tree species form symbiotic relationships with one of two types of mycorrzhae—arbuscular mycorrhizae (AM) and ectomycorrhizal (ECM) fungi. AM- and ECM-dominated forests often have distinct nutrient economies, and there is strong interest in mapping or detecting mycorrhizae over large areas. We explored remotely sensed tree canopy spectral properties to "detect" underlying mycorrhizal association across a gradient of AM- and ECM-dominated forest plots. We used a combination of principal components analysis and statistical mining of reflectance and band differencing across moderate/high-resolution Landsat data in conjunction with phenological signals from stitched seasonal time series and topographic features. This approach was trained and validated against measurements of tree species and mycorrhizal association across more than 60,000 trees throughout the central and eastern US. Using this approach, we were able to predict 81% of the variation in mycorrhizal association (p<0.001). Differences in phenological characteristics between AM- and ECM-associated trees drove the relatively high prediction skill.

  7. Arbuscular mycorrhizal morphology and dark septate fungal associations in medicinal and aromatic plants of Western Ghats, Southern India.

    Science.gov (United States)

    Muthukumar, T; Senthilkumar, M; Rajangam, M; Udaiyan, K

    2006-12-01

    We investigated roots of 107 medicinal and aromatic plants (MAPs) in the Western Ghats region of Southern India for arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) associations. Of the 107 MAPs belonging to 98 genera in 52 families examined, 79 were AM and 38 harbored a DSE association. Typical Arum- and Paris-type mycorrhizas are first reported in the presumed nonmycorrhizal family Amaranthaceae. Similarly, DSE associations are recorded for the first time in nine plant families and 37 plant species. Thirty MAPs had both AM and DSE associations. The number of MAPs having Arum-type mycorrhiza was greater than those having Paris-type. This was more prominent among herbaceous plants than in trees where the Paris-type was predominant. Similarly, the Arum-type was more prevalent in annuals than in perennials. DSE associations were more frequent in herbs and perennials compared to other MAPs.

  8. Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

    DEFF Research Database (Denmark)

    Ravnskov, S.; Larsen, J.; Jakobsen, I.

    2002-01-01

    The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus...... the amount of branched PLFAs suggesting a reduction in the population of Gram-positive bacteria in these cases. In conclusion, the B. cepacia seems to have no impact on neither mycorrhiza formation nor on the functioning of the AM fungus G. intraradices in terms of P transport, whereas our results suggest...... that mycorrhiza might have adverse effects on B. cepacia. (C) 2002 Elsevier Science Ltd. All rights reserved....

  9. Arbuscular mycorrhizal fungi mediated uptake of {sup 137}Cs in leek and ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Klas; Weiliang, Zhong; Maertensson, Anna [Department of Soil Sciences, Swedish University of Agricultural Sciences P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2005-02-15

    In a first experiment of so