scholarly journals Is a Fully Established Arbuscular Mycorrhizal Symbiosis Required for Bioprotection of Pisum sativum Roots against Aphanomyces euteiches?

2000 ◽  
Vol 13 (2) ◽  
pp. 238-241 ◽  
Author(s):  
Sophie Slezack ◽  
Eliane Dumas-Gaudot ◽  
Michel Paynot ◽  
Silvio Gianinazzi
Keyword(s):  
Pisum Sativum ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Arbuscular Mycorrhizal Symbiosis ◽  
Mycorrhizal Symbiosis ◽  
Aphanomyces Euteiches ◽  
Chitinolytic Enzymes ◽  
Pea Roots

Bioprotection of pea roots against Aphanomyces euteiches by the arbuscular mycorrhizal fungus G. mosseae was demonstrated to depend on a fully established symbiosis. This was related with induction of mycorrrhiza-related chitinolytic enzymes. Possible mechanisms implicated in bioprotection are discussed.

scholarly journals Phytohormone production by the arbuscular mycorrhizal fungus Rhizophagus irregularis

2020 ◽  
Author(s):  
Simon Pons ◽  
Sylvie Fournier ◽  
Christian Chervin ◽  
Guillaume Bécard ◽  
Soizic Rochange ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Rhizophagus Irregularis ◽  
Mycorrhizal Symbiosis ◽  
Potential Contribution ◽  
Mutualistic Interaction ◽  
Isopentenyl Adenosine ◽  
Acid Pathway

AbstractArbuscular mycorrhizal symbiosis is a mutualistic interaction between most land plants and fungi of the glomeromycotina subphylum. The initiation, development and regulation of this symbiosis involve numerous signalling events between and within the symbiotic partners. Among other signals, phytohormones are known to play important roles at various stages of the interaction. During presymbiotic steps, plant roots exude strigolactones which stimulate the fungus, and favour the initiation of symbiosis. At later stages, different plant hormone classes can act as positive or negative regulators of the interaction. Although the fungus is known to reciprocally emit regulatory signals, its potential contribution to the phytohormonal pool has received little attention, and has so far only been addressed by indirect assays. In this study, using mass spectrometry, we analyzed phytohormones released into the medium by germinated spores of the arbuscular mycorrhizal fungus Rhizophagus irregularis. We detected the presence of a cytokinin (isopentenyl-adenosine) and an auxin (indole-acetic acid). In addition, we identified a gibberellin (gibberellic acid 4) in spore extracts. We also used gas chromatography to show that R. irregularis produces ethylene from methionine and the α-keto γ-methylthiobutyric acid pathway. These results highlight the possibility for AM fungi to use phytohormones to interact with their host plants, or to regulate their own development.

Identification of a Putative P-Transporter Operon in the Genome of a Burkholderia Strain Living inside the Arbuscular Mycorrhizal Fungus Gigaspora margarita

1999 ◽  
Vol 181 (13) ◽  
pp. 4106-4109 ◽  
Author(s):  
J. M. Ruiz-Lozano ◽  
P. Bonfante
Keyword(s):  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
P Uptake ◽  
Mycorrhizal Symbiosis ◽  
Intracellular Bacteria ◽  
Gigaspora Margarita ◽  
Burkholderia Strain

ABSTRACT This article reports the identification of a putative P-transporter operon in the genome of a Burkholderia sp. living in the cytoplasm of the arbuscular mycorrhizal fungus Gigaspora margarita. Its presence suggests that Burkholderiasp. has the potential for P uptake from this environment. This finding raises new questions concerning the importance of intracellular bacteria for mycorrhizal symbiosis.

Microtubules of the mycorrhizal fungus Glomus intraradices in symbiosis with tomato roots

2001 ◽  
Vol 79 (3) ◽  
pp. 307-313 ◽  
Author(s):  
S Timonen ◽  
F A Smith ◽  
S E Smith
Keyword(s):  
Lycopersicon Esculentum ◽  
Filamentous Fungi ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal Fungus ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Mycorrhizal Symbiosis ◽  
Tomato Roots ◽  
External Mycelium ◽  
First Time

In this study the presence and orientation of fungal microtubules were recorded in arbuscular mycorrhizal symbiosis for the first time. Visualization of the fungal microtubules was achieved by using a protocol specifically labelling only fungal tubulins. Microtubules of external mycelium, intraradical hyphae, arbuscules, and vesicles of the arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith were examined when in symbiosis with tomato (Lycopersicon esculentum Mill.). Microtubules were organized as bundles in both external and intraradical hyphae. The bundles of microtubules extended directly from intraradical hyphae into the arbuscules, where the microtubules remained as bundles in the larger hyphae. In the fine fungal branches of the arbuscules, microtubules were seen as thinner filaments. Fungal microtubules were seen to connect the intraradical hyphae and arbuscules. In addition, microtubules of adjacent arbuscules could continue directly from one arbuscule to another. Microtubules reached to the basal cone of each vesicle, but the live vesicles, containing many nuclei, seemed devoid of any microtubular labelling.Key words: cytoskeleton, endomycorrhiza, filamentous fungi, tomato, tubulin, Zygomycota.

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