Coexistence of genetically different Rhizophagus irregularis isolates induces genes involved in a putative fungal mating response

Abstract Arbuscular mycorrhizal fungi (AMF) are of great ecological importance because of their effects on plant growth. Closely related genotypes of the same AMF species coexist in plant roots. However, almost nothing is known about the molecular interactions occurring during such coexistence. We compared in planta AMF gene transcription in single and coinoculation treatments with two genetically different isolates of Rhizophagus irregularis in symbiosis independently on three genetically different cassava genotypes. Remarkably few genes were specifically upregulated when the two fungi coexisted. Strikingly, almost all of the genes with an identifiable putative function were known to be involved in mating in other fungal species. Several genes were consistent across host plant genotypes but more upregulated genes involved in putative mating were observed in host genotype (COL2215) compared with the two other host genotypes. The AMF genes that we observed to be specifically upregulated during coexistence were either involved in the mating pheromone response, in meiosis, sexual sporulation or were homologs of MAT-locus genes known in other fungal species. We did not observe the upregulation of the expected homeodomain genes contained in a putative AMF MAT-locus, but observed upregulation of HMG-box genes similar to those known to be involved in mating in Mucoromycotina species. Finally, we demonstrated that coexistence between the two fungal genotypes in the coinoculation treatments explained the number of putative mating response genes activated in the different plant host genotypes. This study demonstrates experimentally the activation of genes involved in a putative mating response and represents an important step towards the understanding of coexistence and sexual reproduction in these important plant symbionts.

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Fungos micorrízicos arbusculares influenciam o desempenho hortícola de cultivares de morangueiro

Research Society and Development ◽

10.33448/rsd-v10i7.16972 ◽

2021 ◽

Vol 10 (7) ◽

pp. e45410716972

Author(s):

José Luís Trevizan Chiomento ◽

João Eduardo Carniel de Paula ◽

Fabiola Stockmans De Nardi ◽

Thomas dos Santos Trentin ◽

Fernando Brollo Magro ◽

...

Keyword(s):

Root System ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Mycorrhizal Colonization ◽

Total Flavonoids ◽

Plant Host ◽

Dual Purpose ◽

Total Anthocyanins ◽

Strawberry Cultivars

The inoculation of strawberry cultivars with arbuscular mycorrhizal fungi (AMF) is a profitable and viable biotechnological tool, with potential to improve the horticultural performance of plants. However, this biotechnology is lacking and unknown to producers. The aim of the research was to investigate whether strawberry cultivars in the absence and presence of inoculation with AMF differ in their horticultural performance. The treatments, delineated in a bifactorial scheme, were four strawberry cultivars in the absence and presence of two AMF-based inoculants. The experiment was designed in randomized blocks, with three replications. The root system of ‘Albion’ cultivar showed the highest mycorrhizal colonization. Claroideoglomus etunicatum showed greater capacity to infect plant roots. ‘Portola’ was the most productive cultivar and ‘Albion’ and ‘Aromas’ produced strawberries with the highest levels of total anthocyanins. It is concluded that the use of mycorrhizal biotechnology enhances the levels of total flavonoids in fruits of the ‘Albion’ cultivar inoculated with the fungal species C. etunicatum. The root system of ‘Albion’ cultivar has greater mycorrhizal colonization. The fungal species C. etunicatum is more effective in colonizing the roots of the plant host. It is suggested to use the ‘Portola’ cultivar to obtain higher fruit yields and the ‘Albion’ and ‘Aromas’ cultivars for producers who aim to obtain strawberries with higher levels of total anthocyanins. ‘Aromas’ is recommended for those seeking a dual purpose (production and quality).

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Long reads and Hi-C sequencing illuminate the two-compartment genome of the model arbuscular mycorrhizal symbiont Rhizophagus irregularis

10.1101/2021.08.12.456011 ◽

2021 ◽

Author(s):

Gokalp Yildirir ◽

Jana Sperschneider ◽

Mathu C Malar ◽

Eric CH Chen ◽

Wataru Iwasaki ◽

...

Keyword(s):

Mycorrhizal Fungi ◽

Genome Structure ◽

Arbuscular Mycorrhizal ◽

Genome Biology ◽

Rhizophagus Irregularis ◽

In Planta ◽

Chromosome Conformation ◽

3D Genome ◽

Repeat Content ◽

Host Microbe Interactions

Chromosome folding links genome structure with gene function by generating distinct nuclear compartments and topologically associating domains (TADs). In mammals, these domains undergo preferential interactions and regulate gene expression, however in fungi the role of chromosome folding in genome biology is unclear. Here, we combine Nanopore (ONT) sequencing with chromatin conformation capture sequencing (Hi-C) to reveal chromosome diversity in a group of obligate plant symbionts with a multinucleate mycelium; the arbuscular mycorrhizal fungi (AMF). We find that phylogenetically distinct strains of the model AMF Rhizophagus irregularis all carry 33 chromosomes. Homologous chromosomes show within species variability in size, as well as in gene and repeat content. Strain-specific Hi-C sequencing reveals that all strains have a 3D genome organization that resembles a checkerboard structure with two distinct (A/B) chromatin compartments. Each compartment differs in the level of gene transcription, regulation of candidate effectors and methylation rate. The A-compartment is more gene-dense and contains most core genes, while the B-compartment is more repeat-rich and has higher rates of chromosomal rearrangement. While the B-compartment is transcriptionally repressed, it has significantly more secreted proteins and in planta up-regulated candidate effectors suggesting a possible host-induced change in chromosome conformation. Overall, this study provides a fine-scale view into the genome biology and evolution of prominent plant symbionts, and opens avenues to study the mechanisms that generate and modify chromosome folding during host-microbe interactions.

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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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The methylome of the model arbuscular mycorrhizal fungus, Rhizophagus irregularis, shares characteristics with early diverging fungi and Dikarya

Communications Biology ◽

10.1038/s42003-021-02414-5 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Anurag Chaturvedi ◽

Joaquim Cruz Corella ◽

Chanz Robbins ◽

Anita Loha ◽

Laure Menin ◽

...

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Plant Species ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Rhizophagus Irregularis ◽

Functional Differences ◽

Phosphate Regulation ◽

Very High

AbstractEarly-diverging fungi (EDF) are distinct from Dikarya and other eukaryotes, exhibiting high N6-methyldeoxyadenine (6mA) contents, rather than 5-methylcytosine (5mC). As plants transitioned to land the EDF sub-phylum, arbuscular mycorrhizal fungi (AMF; Glomeromycotina) evolved a symbiotic lifestyle with 80% of plant species worldwide. Here we show that these fungi exhibit 5mC and 6mA methylation characteristics that jointly set them apart from other fungi. The model AMF, R. irregularis, evolved very high levels of 5mC and greatly reduced levels of 6mA. However, unlike the Dikarya, 6mA in AMF occurs at symmetrical ApT motifs in genes and is associated with their transcription. 6mA is heterogeneously distributed among nuclei in these coenocytic fungi suggesting functional differences among nuclei. While far fewer genes are regulated by 6mA in the AMF genome than in EDF, most strikingly, 6mA methylation has been specifically retained in genes implicated in components of phosphate regulation; the quintessential hallmark defining this globally important symbiosis.

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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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Mycorrhizal fungi inoculation and phosphorus fertilizer on growth, essential oil production and nutrient uptake in peppermint (Mentha piperita L.)

Revista Brasileira de Plantas Medicinais ◽

10.1590/s1516-05722012000400018 ◽

2012 ◽

Vol 14 (4) ◽

pp. 692-699 ◽

Cited By ~ 6

Author(s):

M.C. Arango ◽

M.F. Ruscitti ◽

M.G. Ronco ◽

J. Beltrano

Keyword(s):

Essential Oil ◽

Plant Growth ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Glomus Intraradices ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Mentha Piperita ◽

Essential Oil Yield ◽

Essential Oil Production

This study evaluated the effects of inoculation with the arbuscular mycorrhizal fungi Glomus mosseae, Glomus intraradices A4 and Glomus intraradices B1 and two phosphorus levels (10 and 40 mg kg-1) on root colonization, plant growth, nutrient uptake and essential oil content in Mentha piperita L. The experiment was carried out in a greenhouse, in 4x2 factorial arrangement, in completely randomized design. At sixty days after transplanting, the mycorrhizal plants had significantly higher fresh matter, dry matter and leaf area compared to non-mycorrhizal plants. The inoculation increased P, K and Ca levels in the shoot which were higher under 40 mg P kg-1 of soil. Plants grown with 40 mg P kg-1 soil increased the essential oil yield per plant by about 40-50% compared to those cultivated with 10 mg P kg-1, regardless of the mycorrhizal treatment. Among the studied fungal species, inoculation with G. intraradices A4 and a high level of P significantly increased plant growth and essential oil yield, compared to the other studied mycorrhizal fungal species. In conclusion, inoculation of arbuscular mycorrhizal fungi into peppermint plants is a feasible alternative to increase the essential oil production and reduce the use of fertilizers required to obtain economic production of peppermint under phosphorus-deficient soil condition.

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Dual RNA-seq reveals large-scale non-conserved genotype x genotype specific genetic reprograming and molecular crosstalk in the mycorrhizal symbiosis

10.1101/393637 ◽

2018 ◽

Author(s):

Ivan D. Mateus ◽

Frédéric G. Masclaux ◽

Consolée Aletti ◽

Edward C. Rojas ◽

Romain Savary ◽

...

Keyword(s):

Mycorrhizal Fungi ◽

Large Scale ◽

Molecular Mechanisms ◽

Arbuscular Mycorrhizal ◽

Mycorrhizal Symbiosis ◽

Rna Seq ◽

Plant Host ◽

Transcriptional Responses ◽

Plant Genes ◽

Fungal Genetic

AbstractArbuscular mycorrhizal fungi (AMF) impact plant growth and are a major driver of plant diversity and productivity. We quantified the contribution of intra-specific genetic variability in cassava (Manihot esculenta) and Rhizophagus irregularis to gene reprogramming in symbioses using dual RNA-sequencing. A large number of cassava genes exhibited altered transcriptional responses to the fungus but transcription of most of these plant genes (72%) responded in a different direction or magnitude depending on the plant genotype. Two AMF isolates displayed large differences in their transcription, but the direction and magnitude of the transcriptional responses for a large number of these genes was also strongly influenced by the genotype of the plant host. This indicates that unlike the highly conserved plant genes necessary for the symbiosis establishment, plant and fungal gene transcriptional responses are not conserved and are greatly influenced by plant and fungal genetic differences, even at the within-species level. The transcriptional variability detected allowed us to identify an extensive gene network showing the interplay in plant-fungal reprogramming in the symbiosis. Key genes illustrated that the two organisms jointly program their cytoskeleton organisation during growth of the fungus inside roots. Our study reveals that plant and fungal genetic variation plays a strong role in shaping the genetic reprograming in response to symbiosis, indicating considerable genotype x genotype interactions in the mycorrhizal symbiosis. Such variation needs to be considered in order to understand the molecular mechanisms between AMF and their plant hosts in natural communities.

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Arbuscular mycorrhizal fungi (Glomeromycota) of the Vistula Bar

Acta Mycologica ◽

10.5586/am.2002.005 ◽

2014 ◽

Vol 37 (1-2) ◽

pp. 39-62 ◽

Cited By ~ 3

Author(s):

Janusz Błaszkowski ◽

Iwona Adamska ◽

Beata Czerniawska

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Sand Dunes ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Field Samples ◽

North Eastern ◽

Dry Soil ◽

Soil Mixtures ◽

Plant Families

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

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Interspecific differences in the tolerance of arbuscular mycorrhizal fungi to freezing and drying

Canadian Journal of Botany ◽

10.1139/b01-099 ◽

2001 ◽

Vol 79 (10) ◽

pp. 1161-1166 ◽

Cited By ~ 7

Author(s):

John N Klironomos ◽

Miranda M Hart ◽

Jane E Gurney ◽

Peter Moutoglis

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Plant Species ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Fungal Species ◽

Drought Treatment ◽

Interspecific Differences ◽

The Difference ◽

One Year ◽

Arbuscular Mycorrhizal Fungal

Arbuscular mycorrhizal fungal communities in northern temperate ecosystems must function during extremes in environmental conditions. However, it is not known if arbuscular mycorrhizal fungi that co-exist in soil communities have similar tolerances to stresses such as drought and freezing. The phenology of arbuscular mycorrhizal fungi was determined over one year in a community in southern Ontario, Canada. Five fungal species from the same community were then used to inoculate five plant species, in all possible combinations, and were subjected to either a freezing treatment or a drought treatment after which new seedlings were transplanted into the treated pots. The percent colonization of roots of each plant species was measured as the difference in mean colonization from the control. Freezing reduced percent colonization in almost every case, whereas drought resulted in both increased and decreased percent colonization. Fungal species responded differently to the treatments, and there was a pronounced plant × fungus effect. These results support the hypothesis that distinct functional groups of arbuscular mycorrhizal fungi exist, and these may determine plant community structure.Key words: arbuscular mycorrhizal fungi, freezing, drying, functional diversity.

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Detection of arbuscular mycorrhizal fungi associated with pecan (Carya illinoinensis) trees by molecular and morphological approaches

MycoKeys ◽

10.3897/mycokeys.42.26118 ◽

2018 ◽

Vol 42 ◽

pp. 73-88 ◽

Cited By ~ 1

Author(s):

L. Fernández Bidondo ◽

R. P. Colombo ◽

M. Recchi ◽

V. A. Silvani ◽

M. Pérgola ◽

...

Keyword(s):

Fungal Community ◽

Mycorrhizal Fungi ◽

Sequence Similarity ◽

Arbuscular Mycorrhizal ◽

Soil Disturbance ◽

Fungal Species ◽

Fungal Community Composition ◽

Molecular Approaches ◽

Field Samples ◽

Fungal Specificity

Arbuscular mycorrhizal (AM) fungal community associated with pecan (Caryaillinoinensis) roots and rhizospheric soils was assessed by spore isolation and morphological characterisation and by pyrosequencing of AM molecular markers. The AM fungal community associated with pecan growing in the field, was always more diverse than that associated with pecan growing in containers. This was not observed when AM richness was studied, suggesting that soil disturbance by a reduction in host plant richness leads to a less equitable distribution of AM fungal species, in contrast to natural soils. The chosen primers (AMV4.5F/AMDGR) for pyrosequencing showed high AM fungal specificity. Based on 97% sequence similarity, 49 operational taxonomic units (MOTUs) were obtained and, amongst these, 41 MOTUs corresponded to the Glomeromycotaphylum. The number of obtained AM sequences ranged from 2164, associated with field samples, to 5572 obtained from pecan trap pot culture samples, defining 30 and 29 MOTUs, respectively. Richness estimated by conventional species identification was 6 and 9 AM fungal species in soil and pot samples, respectively. Claroideoglomuslamellosum, Funneliformismosseae and Entrophosporainfrequens were the only taxa detected using both techniques. Predominant sequences in the pecan rhizosphere samples, such as Rhizoglomusirregulare and other less abundant (Dominikiairanica, Dominikiaindica, Sclerocystissinuosa, Paraglomuslaccatum), were detected only by pyrosequencing. Detection of AM fungal species based on spore morphology, in combination with molecular approaches, provides a more comprehensive estimate of fungal community composition.

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