Arbuscular mycorrhizal fungi reveal distinct patterns of anastomosis formation and hyphal healing mechanisms between different phylogenic groups

Authors

  • Ivan Enrique De La Providencia,

    1. Instituto Nacional de Ciencias Agricolas (INCA), Km 31/2 Carretera de Tapaste, Gaveta Postal 1, San José de Las Lajas, La Habana, Cuba;
    2. Present address: Université catholique de Louvain, Unité de microbiologie, 3 Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium;
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  • Francisco Adriano De Souza,

    1. Netherlands Institute of Ecology (NIOO-KNAW), PO Box 40, 6966 ZG Heteren, The Netherlands;
    2. Present address: Empresa Brasileira de Pesquisa Agropecuária, Embrapa Agrobiologia, BR 465, Km 47 Caixa Postal 74505, CEP 23890–000, Seropédica, Rio de Janeiro, Brazil;
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  • Félix Fernández,

    1. Instituto Nacional de Ciencias Agricolas (INCA), Km 31/2 Carretera de Tapaste, Gaveta Postal 1, San José de Las Lajas, La Habana, Cuba;
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  • Nathalie Séjalon Delmas,

    1. Equipe de Mycologie Végétale, UMR 5546 CNRS Université Paul Sabatier, Pôle de Biotechnologie Végétale, 24 Chemin de Borde-Rouge, BP 17, 31326 Castanet-Tolosan, France;
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  • Stéphane Declerck

    Corresponding author
    1. Université catholique de Louvain, Mycothèque de l’Université catholique de Louvain (MUCL), Unité de Microbiologie, 3 Place Croix du Sud, 1348 Louvain-la-Neuve, Belgium
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Author for correspondence:Stéphane Declerck Tel: +32 (10) 47 46 44 Fax: +32 (10) 45 15 01 Email: declerck@mbla.ucl.ac.be

Summary

  • • The significance of anastomosis formation and the hyphal healing mechanism (HHM) for functionality and integrity of the arbuscular mycorrhizal (AM) fungal mycelial network remains poorly documented.
  • • Four Glomeraceae and three Gigasporaceae were cultured monoxenically. Anastomosis formation was assessed using the grid line method, while HHM was time-lapse monitored.
  • • In intact mycelial networks, the number of anastomosis per hyphal length was higher for Glomeraceae than for Gigasporaceae strains. Glomeraceae strains studied always formed anastomosis between different hyphae, whereas anastomosis in the Gigasporaceae more often concerned hyphal bridges within the same hyphae. In both families the HHM corresponded to a four-step process; first septum formation; second initiation of growing hyphal tips (GHTs); third GHT elongation, orientation and contact; and fourth GHT fusion and cytoplasmic/protoplasmic flux re-establishment. These four steps differentiated Glomeraceae from Gigasporaceae.
  • • The type and number of anastomosis per hyphal length, and the HHM differed considerably between Glomeraceae and Gigasporaceae families representing a supplementary character that distinguishes these two families and may be of significance in ecological studies of AM fungi.

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