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Maria J. Harrison - One of the best experts on this subject based on the ideXlab platform.
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genome and evolution of the arbuscular mycorrhizal fungus diversispora epigaea formerly Glomus Versiforme and its bacterial endosymbionts
New Phytologist, 2019Co-Authors: Xuepeng Sun, Maria J. Harrison, Wenbo Chen, Sergey Ivanov, Allyson M Maclean, Haley Wight, Thiruvarangan Ramaraj, Joann Mudge, Zhangjun FeiAbstract:Arbuscular mycorrhizal (AM) fungi form endosymbioses with most plants, and they themselves are hosts for Mollicutes/Mycoplasma-related endobacteria (MRE). Despite their significance, genomic information for AM fungi and their MRE are relatively sparse, which hinders our understanding of their biology and evolution. We assembled the genomes of the AM fungus Diversispora epigaea (formerly Glomus Versiforme) and its MRE and performed comparative genomics and evolutionary analyses. The D. epigaea genome showed a pattern of substantial gene duplication and differential evolution of gene families, including glycosyltransferase family 25, whose activities are exclusively lipopolysaccharide biosynthesis. Genes acquired by horizontal transfer from bacteria possibly function in defense against foreign DNA or viruses. The MRE population was diverse, with multiple genomes displaying characteristics of differential evolution and encoding many MRE-specific genes as well as genes of AM fungal origin. Gene family expansion in D. epigaea may enhance adaptation to both external and internal environments, such as expansion of kinases for signal transduction upon external stimuli and expansion of nucleoside salvage pathway genes potentially for competition with MRE, whose genomes lack purine and pyrimidine biosynthetic pathways. Collectively, this metagenome provides high-quality references and begins to reveal the diversity within AM fungi and their MRE.
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cDNA arrays as a tool to identify mycorrhiza-regulated genes: identification of mycorrhiza-induced genes that encode or generate signaling molecules implicated in the control of root growth
Canadian Journal of Botany, 2004Co-Authors: Jinyuan Liu, Laura A. Blaylock, Maria J. HarrisonAbstract:Arbuscular mycorrhizas (AM) are symbiotic associations formed by fungi from the Glomeromycota and most angiosperms. Despite the widespread occurrence of the association, its ecological significance, and its potential importance in agriculture, relatively little is known at the molecular level about the development, functioning, and regulation of the symbiosis. We have selected Medicago truncatula Gaertn. 'Jemalong' and an AM fungus, Glomus Versiforme (Karsten) Berch, for molecular genetic analyses of the AM symbiosis. Here we used macroarrays as a screening tool to enable the rapid identification of genes that show differential expression in mycorrhizal roots. Forty-three genes showing increased transcript levels and 18 genes showing decreased transcripts in mycorrhizal roots were identified. This set contained several genes predicted to encode regulatory proteins including an alpha-fucosidase implicated in the generation of signaling molecules that modulate plant growth and a gene encoding a putative pep...
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Phosphate transporters of Medicago truncatula and arbuscular mycorrhizal fungi
Diversity and Integration in Mycorrhizas, 2002Co-Authors: Wayne K. Versaw, Tzyy-jen Chiou, Maria J. HarrisonAbstract:Most vascular plants acquire phosphate from their environment either directly, via the roots, or indirectly, via a symbiotic interaction with arbuscular mycorrhizal (AM) fungi. The symbiosis develops in the plant roots where the fungi colonize the cortex of the root to obtain carbon from the plant host, while assisting the plant with acquisition of phosphate and other mineral nutrients from the soil solution. As a first step toward understanding the molecular basis of the symbiosis and phosphate utilization, we have cloned and characterized phosphate transporter genes from the AM fungi Glomus Versiforme and Glomus intraradices, and from the roots of a host plant, Medicago truncatula. Expression analyses and localization studies indicate that each of these transporters has a role in phosphate uptake from the soil solution.
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Construction and characterization of genomic libraries of two endomycorrhizal fungi: Glomus Versiforme and Gigaspora margarita
Mycological Research, 1999Co-Authors: Marianne L. Van Buuren, Maria J. Harrison, Luisa Lanfranco, Sabina Longato, Daniela Minerdi, Paola BonfanteAbstract:Arbuscular (AM) mycorrhizal fungi form symbiotic associations with the roots of plants that lead to increased growth and health of many plants. The agricultural application of mycorrhizas has remained difficult since AM fungi are obligate biotrophs that show only very limited growth in the absence of a host. As a first step in the molecular and genetic characterization of these fungi we have constructed genomic libraries of Glomus Versiforme and Gigaspora margarita. We demonstrated that in addition to fungal genes these libraries contain clones derived from the genome of endosymbiotic bacteria that are present in fungal spores. A genomic clone encoding elongation factor 1 alpha (EF-1) was isolated from G. Versiforme and to our knowledge this is the first time a low copy number gene was cloned from an AM fungus. The EF-1 promoter is highly active in mycorrhizal roots and will be an important tool for the expression of foreign genes in the fungus.
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Novel genes induced during an arbuscular mycorrhizal (AM) symbiosis formed between Medicago truncatula and Glomus Versiforme.
Molecular plant-microbe interactions : MPMI, 1999Co-Authors: M. L. Van Buuren, Ignacio E. Maldonado-mendoza, Anthony T. Trieu, Laura A. Blaylock, Maria J. HarrisonAbstract:Many terrestrial plant species are able to form symbiotic associations with arbuscular mycorrhizal fungi. Here we have identified three cDNA clones representing genes whose expression is induced during the arbuscular mycorrhizal symbiosis formed between Medicago truncatula and an arbuscular mycorrhizal fungus, Glomus Versiforme. The three clones represent M. truncatula genes and encode novel proteins: a xyloglucan endotransglycosylaserelated protein, a putative arabinogalactan protein (AGP), and a putative homologue of the mammalian p110 subunit of initiation factor 3 (eIF3). These genes show little or no expression in M. truncatula roots prior to formation of the symbiosis and are significantly induced following colonization by G. Versiforme. The genes are not induced in roots in response to increases in phosphate. This suggests that induction of expression during the symbiosis is due to the interaction with the fungus and is not a secondary effect of improved phosphate nutrition. In situ hybridization r...
Paola Bonfante - One of the best experts on this subject based on the ideXlab platform.
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Intracellular Burkholderia strain has no negative effect on the symbiotic efficiency of the arbuscular mycorrhizal fungus Gigaspora margarita
Plant Growth Regulation, 2001Co-Authors: Juan Manuel Ruiz-lozano, Paola BonfanteAbstract:This study investigates the effects of bacteria occurring in thecytoplasm of some arbuscular mycorrhizal fungi (AMF) on their symbioticefficiency. Gigaspora margarita, Gigasporarosea and Glomus Versiforme, containing orwithout intracellular bacteria, were compared for their efficiency instimulating growth of Lactuca sativa L. Biomass productionand nutrient contents were evaluated in plants grown on two substrates. Theefficiency of G. margarita harbouring a homogenouspopulation of Burkholderia was greater than that of theother two AMF, mainly G. rosea, which does not containintracellular bacteria. When plants were grown in poor soil, inoculation withG. margarita resulted in the best growth rates as well asthe highest N, P and K values. The significantly higher N content is ofparticular importance, since the genome of Burkholderiapossesses nif genes.
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Chitin synthase genes in the arbuscular mycorrhizal fungus Glomus Versiforme: full sequence of a gene encoding a class IV chitin synthase
FEMS microbiology letters, 1999Co-Authors: Luisa Lanfranco, Lilia Garnero, Paola BonfanteAbstract:Chitin synthase genes of the arbuscular mycorrhizal fungus Glomus Versiforme were sought in an investigation of the molecular basis of fungal growth. Three DNA fragments (Gvchs1, Gvchs2 and Gvchs3) corresponding to the conserved regions of distinct chitin synthase (chs) genes were amplified by means of the polymerase chain reaction (PCR) with two sets of degenerate primers. Gvchs1 and Gvchs2 encode two class I chitin synthases, whereas Gvchs3 encodes a class IV chitin synthase. A genomic library was used to obtain the Gvchs3 complete gene (1194 amino acids), which shows a very close similarity to the class IV chitin synthase from Neurospora crassa.
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Construction and characterization of genomic libraries of two endomycorrhizal fungi: Glomus Versiforme and Gigaspora margarita
Mycological Research, 1999Co-Authors: Marianne L. Van Buuren, Maria J. Harrison, Luisa Lanfranco, Sabina Longato, Daniela Minerdi, Paola BonfanteAbstract:Arbuscular (AM) mycorrhizal fungi form symbiotic associations with the roots of plants that lead to increased growth and health of many plants. The agricultural application of mycorrhizas has remained difficult since AM fungi are obligate biotrophs that show only very limited growth in the absence of a host. As a first step in the molecular and genetic characterization of these fungi we have constructed genomic libraries of Glomus Versiforme and Gigaspora margarita. We demonstrated that in addition to fungal genes these libraries contain clones derived from the genome of endosymbiotic bacteria that are present in fungal spores. A genomic clone encoding elongation factor 1 alpha (EF-1) was isolated from G. Versiforme and to our knowledge this is the first time a low copy number gene was cloned from an AM fungus. The EF-1 promoter is highly active in mycorrhizal roots and will be an important tool for the expression of foreign genes in the fungus.
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Hydroxyproline-rich glycoprotein mRNA accumulation in maize root cells colonized by an arbuscular mycorrhizal fungus as revealed by in situ hybridization
Protoplasma, 1997Co-Authors: Raffaella Balestrini, M. Josè-estanyol, Pere Puigdomenech, Paola BonfanteAbstract:To determine whether the expression of cell wall related genes changes during the establishment of an arbuscular mycorrhizal symbiosis (AM), we studied the expression of a maize hydroxyproline-rich glycoprotein (HRGP) gene. In situ hybridization showed that, in differentiated cells of maize roots, mRNA accumulation corresponding to the gene encoding for HRGP was only found when the cells were colonized by the endomycorrhizal fungus Glomus Versiforme .
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Polygalacturonase activity and location in arbuscular mycorrhizal roots of Allium porrum L.
Mycorrhiza, 1995Co-Authors: Renato Peretto, Paola Bonfante, Vittorio Bettini, Francesco Favaron, Paolo AlghisiAbstract:Polygalacturonase activity and location were analysed in leek roots ( Allium porrum L.) colonized by Glomus Versiforme (Karst.) Berch, an arbuscular mycorrhizal (AM) fungus. Polygalacturonase activity in mycorrhizal roots did not differ quantitatively from that found in nonmycorrhizal roots on all of the four harvesting dates. Fractionation of mycorrhizal root extracts by ion-exchange chromatography showed that expression of polygalacturonase was specific to the mutualistic association. Immunofluorescence and immunogold experiments were carried out to locate the polygalacturonase in mycorrhizal roots using a polyclonal antibody raised against a Fusarium moniliforme endopolygalacturonase. Immunolabelling was observed all over the arbuscules (intracellular fungal structures) but particularly at the interface between the arbuscule and the plant membrane. Since pectins are located in this area, we suggest that polygalacturonase produced during the symbiosis could play a role in plant pectin degradation.
Run-jin Liu - One of the best experts on this subject based on the ideXlab platform.
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Effect of vesicular-arbuscular mycorrhizal fungi on verticillium wilt of cotton
Mycorrhiza, 1995Co-Authors: Run-jin LiuAbstract:The development of vesicular-arbuscular mycorrhizal fungi (VAMF): Glomus mosseae (Nicol and Gerd.) Gerdemann and Trappe, Glomus Versiforme (Karsten) Berch, Sclerocystis sinuosa Gerdemann and Bakhi and Verticillium dahliae and the effects of the VAMF on the verticillium wilt of cotton (Gossypium hirsutum L. and Gossypium barbadense L.) were studied with paper pots, black plastic tubes and clay pots under natural growth conditions. All of the tested VAMF were able to infect all the cotton varieties used in the present experiment and typical vesicles and arbuscules were formed in the cortical cells of the cotton roots after inoculation. The cap cells, meristem, differentiating and elongating zones of the root tip were found to be colonized by the VAMF. In the case of most V. dahliae infection, the colonization occurred mostly from the root tip up to 2 cm. VAMF and V. dahliae mutually reduced their percentage of infection when inoculated simultaneously. VAMF inoculation reduced the numbers of germinable microsclerotia in the soil of the mycorrhizosphere, while the quantity of VAM fungal spores in the soil was not influenced by infection of with V. dahliae. The % of arbuscule colonization in roots was negatively correlated with the disease grades, while the numbers of vesicles in roots were not. These results suggest that certain vital competition and antagonistic reactions exist between VAMF and V. dahliae. VAMF reduced the incidence and disease indices of verticillium wilt of cotton during the whole growth phase. It is evident that cotton seedling growth was promoted, flowering was advanced, the numbers of flowers and bolls were increased, and this resulted in an increase in the yield of seed cotton. Among the VAMF species, Glomus Versiforme was the most effective, and Sclerocystis sinuosa was inferior. So far as the author is aware, such an effect of VAMF on the increase of cotton wilt tolerance/resistance is reported here far the first time.
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Detection of pathogenesis-related proteins in cotton plants
Physiological and Molecular Plant Pathology, 1995Co-Authors: Run-jin Liu, C.-y. Shen, W.-f. ChiuAbstract:Abstract Seeds of cotton ( Gossypium hirsutum and Gossypium barbadense ) were sown in pots and inoculated with or without vesicular-arbuscular mycorrhizal fungi (VAMF): Glomus mosseae, Glomus Versiforme or Sclerocystis sinuosa and with or without Verticillium dahliae . The VAMF inoculation improved seedling growth, increased the yield of seed cotton and reduced the incidence and disease index of verticillium wilt. Some new soluble proteins were found in the roots and leaves of the cotton infected with the tested VAMF or V. dahliae . More than 10 types of new proteins were identified as pathogenesis-related proteins (PRs). One of the PRs exhibited chitinase activity. The contents of the PRs were enhanced following inoculation with the VAMF and V. dahliae . Tests in vitro showed that the PRs at certain concentrations were able to retard hyphal growth and kill conidia of V. dahliae .
D. G. Strullu - One of the best experts on this subject based on the ideXlab platform.
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realisation de collections in vitro de Glomus intraradices schenck et smith et Glomus Versiforme karsten et berch et proposition d un cycle de developpement
Comptes rendus de l'Académie des sciences. Série 3 Sciences de la vie, 1997Co-Authors: D. G. Strullu, T Diop, C PlenchetteAbstract:Cette note decrit une methode de production in vitro de mycelium et de spores de Glomus intraradices et de Glomus Versiforme a partir de la forme intraracinaire du champignon. La culture des champignons formant des mycorhizes a vesicules et arbuscules a ete realisee sur racines de carotte transformees par Agrobacterium rhizogenes. Ce procede permet, par des cycles successifs de reisolement et de reinfection, de constituer une collection de souches et de multiplier le materiel biologique. A partir de ces resultats et de donnees publiees, cette note presente une nouvelle proposition de cycle de developpement et de mode de survie, in vitro, des Glomus.
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fr: Constitution of in vitro collections: a proposed life cycle of Glomus
Comptes Rendus de l'Académie des Sciences - Series III - Sciences de la Vie, 1997Co-Authors: D. G. Strullu, Tahir Diop, Christian PlenchetteAbstract:Resume Cette note decrit une methode de production in vitro de mycelium et de spores de Glomus intraradices et de Glomus Versiforme a partir de la forme intraracinaire du champignon. La culture des champignons formant des mycorhizes a vesicules et arbuscules a ete realisee sur racines de carotte transformees par Agrobacterium rhizogenes . Ce procede permet, par des cycles successifs de reisolement et de reinfection, de constituer une collection de souches et de multiplier le materiel biologique. A partir de ces resultats et de donnees publiees, cette note presente une nouvelle proposition de cycle de developpement et de mode de survie, in vitro, des Glomus .
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Entrapment of in vitro produced spores of Glomus Versiforme in alginate beads: in vitro and in vivo inoculum potentials
Journal of Biotechnology, 1996Co-Authors: Stephan Declerck, D. G. Strullu, Christian Plenchette, T GuillemetteAbstract:In vitro produced spores of Glomus Versiforme were entrapped in alginate beads and their inoculum potentials evaluated by a biological assay. Encapsulated spores were able to germinate and the regenerated mycelium kept its ability to infect roots under controlled conditions. We estimated to 65.8 the number of beads needed, each containing four spores, to infect 50% of a population of susceptible plantlets. These results show the possibility to encapsulate in vitro produced spores and therefore represent a new kind of high quality inoculum, free of pathogens.
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In vitro mass-production of the arbuscular mycorrhizal fungus, Glomus Versiforme, associated with Ri T-DNA transformed carrot roots
Mycological Research, 1996Co-Authors: Stéphane Declerck, D. G. Strullu, Christian PlenchetteAbstract:The rate of in vitro spore formation of the arbuscular mycorrhizal fungus Glomus Versiforme was followed in Petri dishes, using mycorrhizal root-segment inoculum associated with Ri T-DNA transformed carrot roots. Three phases of sporulation were observed: a lag phase, a period of intensive spore production and a plateau phase. An average of 9500 spores per Petri dish was produced after 5 months of dual culture. The root-organ culture system supported extensive root colonization, with many arbuscules and vesicles being formed. The fungus, both within root-segments and as spores produced, was viable and able to complete its life cycle in vitro. The mycorrhizal root-segments, however, exhibited higher inoculum potential due to the numerous vesicles and extensive intraradical mycelium.
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Infectivity of monoaxenic subcultures of the arbuscular mycorrhizal fungus Glomus Versiforme associated with RI-T-DNA-transformed carrot root
Applied Microbiology and Biotechnology, 1996Co-Authors: Christian Plenchette, Stephan Declerck, T.a. Diop, D. G. StrulluAbstract:Glomus Versiforme was associated in vitro with Ri-T-DNA-transformed carrot root and after 4 months of cultivation, numerous axenic arbuscular mycorrhizal (AM) propagules were obtained. Three successive generations of spores and mycorrhizal root pieces were obtained by reassociating a 4-month-old root piece with a new carrot root. A biological test was conducted to assess the infectivity of the three generations of inoculum. Both for spores and mycorrhizal root pieces, a significant decrease in infectivity was observed among the successive generations. Mycorrhizal root pieces however, exhibited, higher infectivity than spores. These results show the possibility of maintaining AM fungi cultures in axenic conditions for a long time and raise questions about the loss of infectivity among the generations. The necessity of maintaining the same strains in vitro and in vivo in two separate collections is discussed.
Christian Plenchette - One of the best experts on this subject based on the ideXlab platform.
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fr: Constitution of in vitro collections: a proposed life cycle of Glomus
Comptes Rendus de l'Académie des Sciences - Series III - Sciences de la Vie, 1997Co-Authors: D. G. Strullu, Tahir Diop, Christian PlenchetteAbstract:Resume Cette note decrit une methode de production in vitro de mycelium et de spores de Glomus intraradices et de Glomus Versiforme a partir de la forme intraracinaire du champignon. La culture des champignons formant des mycorhizes a vesicules et arbuscules a ete realisee sur racines de carotte transformees par Agrobacterium rhizogenes . Ce procede permet, par des cycles successifs de reisolement et de reinfection, de constituer une collection de souches et de multiplier le materiel biologique. A partir de ces resultats et de donnees publiees, cette note presente une nouvelle proposition de cycle de developpement et de mode de survie, in vitro, des Glomus .
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Entrapment of in vitro produced spores of Glomus Versiforme in alginate beads: in vitro and in vivo inoculum potentials
Journal of Biotechnology, 1996Co-Authors: Stephan Declerck, D. G. Strullu, Christian Plenchette, T GuillemetteAbstract:In vitro produced spores of Glomus Versiforme were entrapped in alginate beads and their inoculum potentials evaluated by a biological assay. Encapsulated spores were able to germinate and the regenerated mycelium kept its ability to infect roots under controlled conditions. We estimated to 65.8 the number of beads needed, each containing four spores, to infect 50% of a population of susceptible plantlets. These results show the possibility to encapsulate in vitro produced spores and therefore represent a new kind of high quality inoculum, free of pathogens.
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In vitro mass-production of the arbuscular mycorrhizal fungus, Glomus Versiforme, associated with Ri T-DNA transformed carrot roots
Mycological Research, 1996Co-Authors: Stéphane Declerck, D. G. Strullu, Christian PlenchetteAbstract:The rate of in vitro spore formation of the arbuscular mycorrhizal fungus Glomus Versiforme was followed in Petri dishes, using mycorrhizal root-segment inoculum associated with Ri T-DNA transformed carrot roots. Three phases of sporulation were observed: a lag phase, a period of intensive spore production and a plateau phase. An average of 9500 spores per Petri dish was produced after 5 months of dual culture. The root-organ culture system supported extensive root colonization, with many arbuscules and vesicles being formed. The fungus, both within root-segments and as spores produced, was viable and able to complete its life cycle in vitro. The mycorrhizal root-segments, however, exhibited higher inoculum potential due to the numerous vesicles and extensive intraradical mycelium.
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Infectivity of monoaxenic subcultures of the arbuscular mycorrhizal fungus Glomus Versiforme associated with RI-T-DNA-transformed carrot root
Applied Microbiology and Biotechnology, 1996Co-Authors: Christian Plenchette, Stephan Declerck, T.a. Diop, D. G. StrulluAbstract:Glomus Versiforme was associated in vitro with Ri-T-DNA-transformed carrot root and after 4 months of cultivation, numerous axenic arbuscular mycorrhizal (AM) propagules were obtained. Three successive generations of spores and mycorrhizal root pieces were obtained by reassociating a 4-month-old root piece with a new carrot root. A biological test was conducted to assess the infectivity of the three generations of inoculum. Both for spores and mycorrhizal root pieces, a significant decrease in infectivity was observed among the successive generations. Mycorrhizal root pieces however, exhibited, higher infectivity than spores. These results show the possibility of maintaining AM fungi cultures in axenic conditions for a long time and raise questions about the loss of infectivity among the generations. The necessity of maintaining the same strains in vitro and in vivo in two separate collections is discussed.