Medicago truncatula ENOD11: A Novel RPRP-Encoding Early Nodulin Gene Expressed During Mycorrhization in Arbuscule-Containing Cells

Leguminous plants establish endosymbiotic associations with both rhizobia (nitrogen fixation) and arbuscular mycorrhizal fungi (phosphate uptake). These associations involve controlled entry of the soil microsymbiont into the root and the coordinated differentiation of the respective partners to generate the appropriate exchange interfaces. As part of a study to evaluate analogies at the molecular level between these two plant-microbe interactions, we focused on genes from Medicago truncatula encoding putative cell wall repetitive proline-rich proteins (RPRPs) expressed during the early stages of root nodulation. Here we report that a novel RPRP-encoding gene, MtENOD11, is transcribed during preinfection and infection stages of nodulation in root and nodule tissues. By means of reverse transcription-polymerase chain reaction and a promoter-reporter gene strategy, we demonstrate that this gene is also expressed during root colonization by endomycorrhizal fungi in inner cortical cells containing recently formed arbuscules. In contrast, no activation of MtENOD11 is observed during root colonization by a nonsymbiotic, biotrophic Rhizoctonia fungal species. Analysis of transgenic Medicago spp. plants expressing pMtENOD11-gusA also revealed that this gene is transcribed in a variety of nonsymbiotic specialized cell types in the root, shoot, and developing seed, either sharing high secretion/metabolite exchange activity or subject to regulated modifications in cell shape. The potential role of early nodulins with atypical RPRP structures such as ENOD11 and ENOD12 in symbiotic and nonsymbiotic cellular contexts is discussed.

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Vesicular–arbuscular mycorrhizal fungi associated with native tall grass prairie and cultivated winter wheat

Canadian Journal of Botany ◽

10.1139/b83-231 ◽

1983 ◽

Vol 61 (8) ◽

pp. 2140-2146 ◽

Cited By ~ 56

Author(s):

B. A. Daniels Hetrick ◽

J. Bloom

Keyword(s):

Winter Wheat ◽

Mycorrhizal Fungi ◽

Root Colonization ◽

Fungal Spores ◽

Arbuscular Mycorrhizal ◽

Growing Season ◽

Fungal Species ◽

Tall Grass ◽

Wheat Field ◽

Vesicular Arbuscular

More vesicular–arbuscular mycorrhizal (VAM) fungal species and significantly more fungal spores were recovered from undisturbed prairie soils than four winter wheat field soils in Kansas through the 1980–1981 growing season. Two previously undescribed sporocarpic species of Endogonaceae were found in prairie samples but have not been successfully established in pot culture, leaving the genus to which they belong unclear. Though variable, 11–50% VAM root colonization was evident in all prairie grass roots sampled throughout the year. In contrast, no identifiable VAM root colonization was evident in wheat until May after flowering when 27% root colonization was observed. During the 1981–1982 growing season, roots of two other wheat fields were sampled with similar results. No colonization occurred until May when 8% root colonization was evident. The possible influence of such low levels of root colonization occurring quite late in the growing season of winter wheat is discussed.

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The Medicago truncatula Sucrose Synthase Gene MtSucS1 Is Activated Both in the Infected Region of Root Nodules and in the Cortex of Roots Colonized by Arbuscular Mycorrhizal Fungi

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.10.903 ◽

2003 ◽

Vol 16 (10) ◽

pp. 903-915 ◽

Cited By ~ 77

Author(s):

Natalija Hohnjec ◽

Andreas M. Perlick ◽

Alfred Pühler ◽

Helge Küster

Keyword(s):

Medicago Truncatula ◽

Mycorrhizal Fungi ◽

Sucrose Synthase ◽

Root Nodules ◽

Arbuscular Mycorrhizal ◽

Grain Legume ◽

Sink Strength ◽

Cortical Cells ◽

Model Legume ◽

Microbial Symbionts

The MtSucS1 gene encodes a sucrose synthase (EC 2.4.1.13) in the model legume Medicago truncatula. To determine the expression pattern of this gene in different organs and in particular during root endosymbioses, we transformed M. truncatula with specific regions of MtSucS1 fused to the gusAint reporter gene. These fusions directed an induction to the vasculature of leaves, stems, and roots as well as to flowers, developing seeds, young pods, and germinating seedlings. In root nodules, strong promoter activity occurred in the infected cells of the nitrogen-fixing zone but was additionally observed in the meristematic region, the prefixing zone, and the inner cortex, including the vasculature. Concerning endomycorrhizal roots, the MtSucS1 promoter mediated strongest expression in cortical cells harboring arbuscules. Specifically in highly colonized root sections, GUS-staining was furthermore detected in the surrounding cortical cells, irrespective of a direct contact with fungal structures. In accordance with the presence of an orthologous PsSus1 gene, we observed a comparable regulation of MtSucS1 expression in the grain legume Pisum sativum in response to microbial symbionts. Unlike other members of the MtSucS gene family, the presence of rhizobial or Glomus microsymbionts significantly altered and enhanced MtSucS1 gene expression, leading us to propose that MtSucS1 is involved in generating sink-strength, not only in root nodules but also in mycorrhizal roots.

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Novel Genes Induced During an Arbuscular Mycorrhizal (AM) Symbiosis Formed Between Medicago truncatula and Glomus versiforme

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1999.12.3.171 ◽

1999 ◽

Vol 12 (3) ◽

pp. 171-181 ◽

Cited By ~ 63

Author(s):

Marianne L. van Buuren ◽

Ignacio E. Maldonado-Mendoza ◽

Anthony T. Trieu ◽

Laura A. Blaylock ◽

Maria J. Harrison

Keyword(s):

Medicago Truncatula ◽

Mycorrhizal Fungi ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Arabinogalactan Protein ◽

Initiation Factor ◽

Wall Structure ◽

Cdna Clones ◽

Cortical Cells ◽

Glomus Versiforme

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 revealed that the putative AGP is expressed specifically in cortical cells containing arbuscules. The identification of two mycorrhiza-induced genes encoding proteins predicted to be involved in cell wall structure is consistent with previous electron microscopy data that indicated major alterations in the extracellular matrix of the cortical cells following colonization by mycorrhizal fungi.

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Effects of different vesicular–arbuscular mycorrhizal fungi on growth of Fraxinusamericana

Canadian Journal of Forest Research ◽

10.1139/x83-085 ◽

1983 ◽

Vol 13 (4) ◽

pp. 589-593 ◽

Cited By ~ 15

Author(s):

Valentin Furlan ◽

J. André Fortin ◽

Christian Plenchette

Keyword(s):

Mycorrhizal Fungi ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Dry Mass ◽

Fungal Species ◽

Growth Enhancement ◽

White Ash ◽

Vesicular Arbuscular ◽

The Difference ◽

Glomus Sp

White ash seedlings (Fraxinusamericana L.) were inoculated with five species of endomycorrhizal fungi. On the 2nd week after transplantation, growth of inoculated plants differed from control plants. Growth also differed between each fungal species used, but the difference decreased after 82 days of culture. Only dry mass remained higher in plants inoculated with Glomusepigaeum Daniels & Trappe, Glomus sp. No. 3, and Glomusmonosporum Gerd. & Trappe. A significant growth enhancement was obtained even with a low level of root colonization.

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Faculty Opinions recommendation of Arbuscular mycorrhizal fungi elicit a novel intracellular apparatus in Medicago truncatula root epidermal cells before infection.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1029145.342564 ◽

2005 ◽

Author(s):

Martin Parniske

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Medicago Truncatula ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Epidermal Cells

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Occurrence of Vesicular-Arbuscular Mycorrhizal Fungi in Alberta, Canada

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-11-1216 ◽

1993 ◽

Vol 48 (11-12) ◽

pp. 923-929 ◽

Cited By ~ 3

Author(s):

S. M. Boyetchko ◽

J. P. Tewari

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Glomus Aggregatum ◽

X Ray ◽

Vesicular Arbuscular ◽

Spore Walls ◽

Scanning Electron

Abstract Three V A mycorrhizal fungal species were isolated from soils in Alberta, Canada and examined by scanning electron microscopy and energy-dispersive X-ray microanalysis. Mature spores of Glomus aggregatum developed an outer hyaline wall which contained lower levels of calcium than the middle wall. Examination of G. pansihalos spores revealed a lower level of calcium in the outer evanescent wall as compared to the ornamented wall. When spores of Entrophospora infrequens were examined, the wall of the vesicle was found to contain similar levels of calcium as the ornamented wall of the spore. The significance of the results concerning the presence of calcium in mycorrhizal spore walls is discussed, as is the occurrence of the mycorrhizal species.

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Micro-Landscape Dependent Changes in Arbuscular Mycorrhizal Fungal Community Structure

Applied Sciences ◽

10.3390/app11115297 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5297

Author(s):

Stavros D. Veresoglou ◽

Leonie Grünfeld ◽

Magkdi Mola

Keyword(s):

Community Structure ◽

Mycorrhizal Fungi ◽

Root Colonization ◽

Environmental Parameters ◽

Arbuscular Mycorrhizal ◽

Fungal Community Structure ◽

High Connectivity ◽

Spatio Temporal ◽

Arbuscular Mycorrhizal Fungal ◽

Colonization Rates

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make them more or less predictable in time and space. Here we present results from three controlled experiments, where we manipulated two environmental parameters, habitat connectance and habitat quality, to address the degree to which plant roots in archipelagos of high connectivity and invariable habitats are colonized with (i) less diverse and (ii) easier to predict AMF assemblages. We observed no differences in diversity across our manipulations. We show, however, that mixing habitats and varying connectivity render AMF assemblages less predictable, which we could only detect within and not between our experimental units. We also demonstrate that none of our manipulations favoured any specific AMF taxa. We present here evidence that the community structure of AMF is less responsive to spatio-temporal manipulations than root colonization rates which is a facet of the symbiosis which we currently poorly understand.

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Prepenetration Apparatus Assembly Precedes and Predicts the Colonization Patterns of Arbuscular Mycorrhizal Fungi within the Root Cortex of Both Medicago truncatula and Daucus carota

The Plant Cell ◽

10.1105/tpc.108.059014 ◽

2008 ◽

Vol 20 (5) ◽

pp. 1407-1420 ◽

Cited By ~ 198

Author(s):

Andrea Genre ◽

Mireille Chabaud ◽

Antonella Faccio ◽

David G. Barker ◽

Paola Bonfante

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Medicago Truncatula ◽

Daucus Carota ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Root Cortex ◽

Colonization Patterns

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Seasonal Diversity of Arbuscular Mycorrhizal Fungi in Mangroves of Goa, India

International Journal of Biodiversity ◽

10.1155/2013/196527 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 12

Author(s):

James D’Souza ◽

Bernard Felinov Rodrigues

Keyword(s):

Species Richness ◽

Mycorrhizal Fungi ◽

Monsoon Season ◽

Arbuscular Mycorrhizal ◽

Fungal Spore ◽

Fungal Species ◽

Spore Density ◽

Species Variation ◽

Fungal Community Composition ◽

Mangrove Plant

Seasonal dynamics of arbuscular mycorrhizal (AM) fungal community composition in three common mangrove plant species, namely, Acanthus ilicifolius, Excoecaria agallocha, and Rhizophora mucronata, from two sites in Goa, India, were investigated. In all three species variation in AM fungal spore density was observed. Maximum spore density and AM species richness were recorded in the premonsoon season, while minimum spore density and richness were observed during monsoon season at both sites. A total of 11 AM fungal species representing five genera were recorded. Acaulospora laevis was recorded in all seasons at both sites. Multivariate analysis revealed that season and host coaffected AM spore density and species richness with the former having greater influence than the latter.

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