Acclimatization of Rhizophagus irregularis Enhances Zn Tolerance of the Fungus and the Mycorrhizal Plant Partner

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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Proteome adaptations under contrasting soil phosphate regimes of Rhizophagus irregularis engaged in a common mycorrhizal network

Fungal Genetics and Biology ◽

10.1016/j.fgb.2021.103517 ◽

2021 ◽

Vol 147 ◽

pp. 103517

Author(s):

Ghislaine Recorbet ◽

Silvia Calabrese ◽

Thierry Balliau ◽

Michel Zivy ◽

Daniel Wipf ◽

...

Keyword(s):

Rhizophagus Irregularis ◽

Soil Phosphate ◽

Mycorrhizal Network ◽

Common Mycorrhizal Network

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S-Nitrosothiol Signaling Is involved in Regulating Hydrogen Peroxide Metabolism of Zinc-Stressed Arabidopsis

Plant and Cell Physiology ◽

10.1093/pcp/pcz138 ◽

2019 ◽

Vol 60 (11) ◽

pp. 2449-2463 ◽

Cited By ~ 5

Author(s):

Zs Kolbert ◽

ï¿½ Molnï¿½r ◽

D Olï¿½h ◽

G Feigl ◽

E Horvï¿½th ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Plant Cells ◽

Thioredoxin Reductase ◽

Protein S ◽

Protein Nitration ◽

Wild Type ◽

Accumulation Capacity ◽

Zn Tolerance ◽

Activity Loss ◽

New Evidence

Abstract Accumulation of heavy metals such as zinc (Zn) disturbs the metabolism of reactive oxygen (e.g. hydrogen peroxide, H2O2) and nitrogen species (e.g. nitric oxide, NO; S-nitrosoglutathione, GSNO) in plant cells; however, their signal interactions are not well understood. Therefore, this study examines the interplay between H2O2 metabolism and GSNO signaling in Arabidopsis. Comparing the Zn tolerance of the wild type (WT), GSNO reductase (GSNOR) overexpressor 35S::FLAG-GSNOR1 and GSNOR-deficient gsnor1-3, we observed relative Zn tolerance of gsnor1-3, which was not accompanied by altered Zn accumulation capacity. Moreover, in gsnor1-3 plants Zn did not induce NO/S-nitrosothiol (SNO) signaling, possibly due to the enhanced activity of NADPH-dependent thioredoxin reductase. In WT and 35S::FLAG-GSNOR1, GSNOR was inactivated by Zn, and Zn-induced H2O2 is directly involved in the GSNOR activity loss. In WT seedlings, Zn resulted in a slight intensification of protein nitration detected by Western blot and protein S-nitrosation observed by resin-assisted capture of SNO proteins (RSNO-RAC). LC-MS/MS analyses indicate that Zn induces the S-nitrosation of ascorbate peroxidase 1. Our data collectively show that Zn-induced H2O2 may influence its own level, which involves GSNOR inactivation-triggered SNO signaling. These data provide new evidence for the interplay between H2O2 and SNO signaling in Arabidopsis plants affected by metal stress.

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The arbuscular mycorrhizal fungus Rhizophagus irregularis affects arthropod colonization on sweet pepper in both the field and greenhouse

Journal of Pest Science ◽

10.1007/s10340-017-0844-1 ◽

2017 ◽

Vol 90 (3) ◽

pp. 935-946 ◽

Cited By ~ 4

Author(s):

Adalbert Balog ◽

Hugh D. Loxdale ◽

János Bálint ◽

Klára Benedek ◽

Károly-Attila Szabó ◽

...

Keyword(s):

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Sweet Pepper ◽

Rhizophagus Irregularis

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Hyphal colonization of Rhizophagus irregularis increases unsaturated hydraulic conductivity of a loamy sand distant from roots

10.5194/egusphere-egu21-4564 ◽

2021 ◽

Author(s):

Michael Bitterlich ◽

Richard Pauwels

Keyword(s):

Hydraulic Conductivity ◽

Water Content ◽

Hydraulic Properties ◽

Volumetric Water Content ◽

Rhizophagus Irregularis ◽

Loamy Sand ◽

Soil Hydraulic Properties ◽

Unsaturated Hydraulic Conductivity ◽

Soil Hydraulic ◽

Root Exclusion

Hydraulic properties of mycorrhizal soils have rarely been reported and difficulties in directly assigning potential effects to hyphae of arbuscular mycorrhizal fungi (AMF) arise from other consequences of AMF being present, i.e. their influence on growth and water consumption rates of their host plants that both also influence soil hydraulic properties.We assumed that the typical nylon meshes used for root-exclusion experiments in mycorrhizal research can provide a dynamic hydraulic barrier. It is expected that the uniform pore size of the rigid meshes causes a sudden hydraulic decoupling of the enmeshed inner volume from the surrounding soil as soon as the mesh pores become air-filled. Growing plants below the soil moisture threshold for hydraulic decoupling would minimize plant-size effects on root-exclusion compartments and allow for a more direct assignment of hyphal presence to modulations in soil hydraulic properties.We carried out water retention and hydraulic conductivity measurements with two tensiometers introduced in two different heights in a cylindrical compartment (250 cm&#179;) containing a loamy sand, either with or without the introduction of a 20 &#181;m nylon mesh equidistantly between the tensiometers. Introduction of a mesh reduced hydraulic conductivity across the soil volumes by two orders of magnitude from 471 to 6 &#181;m d-1 at 20% volumetric water content.We grew maize plants inoculated or not with Rhizophagus irregularis in the same soil in pots that contained root-exclusion compartments while maintaining 20% volumetric water content. When hyphae were present in the compartments, water potential and unsaturated hydraulic conductivity increased for a given water content compared to compartments free of hyphae. These differences increased with progressive soil drying.We conclude that water extractability from soils distant to roots can be facilitated under dry conditions when AMF hyphae are present.&#160;

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