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

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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Investigating unexplained genetic variation and its expression in the arbuscular mycorrhizal fungus Rhizophagus irregularis

10.1101/682385 ◽

2019 ◽

Cited By ~ 1

Author(s):

Frédéric G. Masclaux ◽

Tania Wyss ◽

Marco Pagni ◽

Pawel Rosikiewicz ◽

Ian R. Sanders

Keyword(s):

Genetic Variation ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Rhizophagus Irregularis ◽

Published Data ◽

Strong Indication ◽

Distinct Nucleus

SummaryArbuscular mycorrhizal fungi (AMF) are important symbionts of plants. Recently, studies of the AMF Rhizophagus irregularis recorded within-isolate genetic variation that does not completely match the proposed homokaryon or heterokaryon state (where heterokaryons comprise a population of two distinct nucleus genotypes). We re-analysed published data showing that bi-allelic sites (and their frequencies), detected in proposed homo- and heterokaryote R. irregularis isolates, were similar across independent studies using different techniques. This indicated that observed within-fungus genetic variation was not an artefact of sequencing and that such within-fungus genetic variation possibly exists. We looked to see if bi-allelic transcripts from three R. irregularis isolates matched those observed in the genome as this would give a strong indication of whether bi-allelic sites recorded in the genome were reliable variants. In putative homokaryon isolates, very few bi-allelic transcripts matched those in the genome. In a putative heterokaryon, a large number of bi-allelic transcripts matched those in the genome. Bi-allelic transcripts also occurred in the same frequency in the putative heterokaryon as predicted from allele frequency in the genome. Our results indicate that while within-fungus genome variation in putative homokaryon and heterokaryon AMF was highly similar in 2 independent studies, there was little support that this variation is transcribed in homokaryons. In contrast, within-fungus variation thought to be segregated among two nucleus genotypes in a heterokaryon isolate was indeed transcribed in a way that is proportional to that seen in the genome.

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The arbuscular mycorrhizal fungus Rhizophagus irregularis MUCL 41833 increases the phosphorus uptake and biomass of Medicago truncatula, a benzo[a]pyrene-tolerant plant species

Mycorrhiza ◽

10.1007/s00572-018-0861-9 ◽

2018 ◽

Vol 28 (8) ◽

pp. 761-771 ◽

Cited By ~ 4

Author(s):

Maryline Calonne-Salmon ◽

Katia Plouznikoff ◽

Stéphane Declerck

Keyword(s):

Plant Species ◽

Medicago Truncatula ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Phosphorus Uptake ◽

Arbuscular Mycorrhizal ◽

Rhizophagus Irregularis ◽

Tolerant Plant

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Arbuscular mycorrhizal fungi and auxin associated with microelements in the development of cuttings of Varronia leucocephala

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v23n3p167-174 ◽

2019 ◽

Vol 23 (3) ◽

pp. 167-174 ◽

Cited By ~ 1

Author(s):

Mônica D. S. da S. Fernandes ◽

Marciana B. de Morais ◽

Francisco F. Mesquita-Oliveira ◽

Cláudia Ulisses ◽

José F. de Medeiros ◽

...

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Aerial Part ◽

Root Formation ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Spore Density ◽

Number Of Leaves ◽

Therapeutic Properties

ABSTRACT The plant Varronia leucocephala is widely used in Brazil for its therapeutic properties. However, a major problem for the seedlings is the low percentage of root formation. The objective of this study was to establish a rooting protocol for V. leucocephala cuttings, using phytoregulators and microelements associated with arbuscular mycorrhizal fungi. The auxin indole-3-butyric acid (IBA) concentration of 1500 mg L-1 showed the best rooting percentage, and it is proposed associating the microelements zinc and boron with the highest IBA doses. Although an increase in the rooting percentage was observed in the presence of zinc, it was not the most suitable for improving the percentage of propagation. Consequently, association of arbuscular mycorrhizal fungi with 1500 mg L-1 IBA plus zinc was selected to evaluate the rooting percentage and sprouting of the aerial part, dry biomass of roots and aerial part, number of leaves, height, mycorrhizal colonization and dependency, spore density, and nutrients of branches and roots. These results show that using zinc with the highest doses of IBA (1500 mg L-1) in plants inoculated with the arbuscular mycorrhizal fungus (Gigaspora albida) was the most effective at promoting the vegetative propagation of V. leucocephala.

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Seed exudates of Sesbania virgata (Cav.) Pers. stimulate the asymbiotic phase of the arbuscular mycorrhizal fungus Gigaspora albida Becker & Hall

Hoehnea ◽

10.1590/2236-8906-27/2018 ◽

2019 ◽

Vol 46 (1) ◽

Cited By ~ 1

Author(s):

Leilyane C.S. Coelho ◽

Daiane S.B. Mignoni ◽

Fábio S.B. Silva ◽

Márcia R. Braga

Keyword(s):

Secondary Metabolites ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Mycelial Growth ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Sesbania Virgata ◽

Positive Effect ◽

Gigaspora Albida

ABSTRACT Sesbania virgata is a legume used in the restoration of degraded areas and forms a symbiosis with arbuscular mycorrhizal fungi (AMF). Its seeds exude secondary metabolites that may influence the colonization by AMF. In this work, we studied the effects of seed (SE) and root exudates (RE) of S. virgata on the asymbiotic phase of Gigaspora albida. Spores of G. albida were germinated in medium supplemented with different concentrations of SE or RE. After seven days, spore germination was stimulated (46.6%) in the medium supplemented with the highest concentration of SE, while the mycelial growth was stimulated with the lowest SE concentration. In turn, RE had no effect on the fungal asymbiotic phase. We concluded that SE exert a positive effect on the asymbiotic phase of G. albida and that the different effects between SE and RE of S. virgata can be explained by their distinct content of secondary metabolites.

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Identification of a Δ11 desaturase from the arbuscular mycorrhizal fungus Rhizophagus irregularis

10.1101/2020.01.13.903815 ◽

2020 ◽

Author(s):

Henry Cheeld ◽

Govindprasad Bhutada ◽

Frederic Beaudoin ◽

Peter J Eastmond

Keyword(s):

Fatty Acid ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal Fungus ◽

Vaccenic Acid ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Fatty Acyl ◽

Rhizophagus Irregularis ◽

Fatty Acyl Moiety ◽

Fatty Acid Species

AbstractArbuscular mycorrhizal fungi are oleaginous organisms and the most abundant fatty acyl moiety usually found in their lipids is palmitvaccenic acid (16:1Δ11cis). However, it is not known how this uncommon fatty acid species is made. Here we have cloned two homologs of Lepidopteran fatty acyl-CoenzymeA Δ11 desaturases from Rhizophagus irregularis. Both DES1 and DES2 are expressed in intraradicle mycelium and can complement the unsaturated fatty acid-requiring auxotrophic growth phenotype of the Saccharomyces cerevisiae ole1Δ mutant. DES1 expression leads almost exclusively to oleic acid (18:1Δ9cis) production, whereas DES2 expression results in the production of 16:1Δ11cis and vaccenic acid (18:1Δ11cis). DES2 therefore encodes a Δ11 desaturase that is likely to be responsible for the synthesis of 16:1Δ11cis in R. irregularis.

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Effect of Vesicular–Arbuscular Mycorrhizal Fungi on Rooting of Sciadopitys verticillata Sieb & Zucc. Cuttings

HortScience ◽

10.21273/hortsci.30.1.133 ◽

1995 ◽

Vol 30 (1) ◽

pp. 133-134 ◽

Cited By ~ 6

Author(s):

D.D. Douds ◽

G. Bécard ◽

P.E. Pfeffer ◽

L.W. Doner ◽

T.J. Dymant ◽

...

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Host Plant ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Root Number ◽

Vesicular Arbuscular Mycorrhizal Fungi ◽

Vesicular Arbuscular ◽

Sciadopitys Verticillata

A vesicular–arbuscular mycorrhizal fungus in a peat-based medium significantly increased survival, callus development, and rooting percentage of Sciadopitys verticillata cuttings over noninoculated cuttings. The presence of a nurse host plant for the mycorrhizal fungi to colonize in the absence of S. verticillata roots decreased survival and rooting percentage, but not callus development, relative to the fungus without the nurse host. Among plants that did produce roots, however, there were no significant differences among treatments for root number, weight, or length per cutting.

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