HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

What's this?

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Duckett, J. G. Articles by Ligrone, R. Search for Related Content PubMed Articles by Duckett, J. G. Articles by Ligrone, R. Agricola Articles by Duckett, J. G. Articles by Ligrone, R. Social Bookmarking                            What's this?

A highly differentiated glomeromycotean association with the mucilage-secreting, primitive antipodean liverwort Treubia (Treubiaceae): clues to the origins of mycorrhizas¹

²School of Biological Sciences, Queen Mary University of London, Mile End Road, London E3 4NS, UK; ³Dipartimento di Scienze ambientali, Seconda Università di Napoli, via A. Vivaldi 43, 81100 Caserta, Italy

ABSTRACT

Thallus anatomy in three species of the primitive liverwort genus Treubia (Metzgeriidae, Treubiales) was studied by light and electron microscopy. The thallus exudes copious mucilage, a feature shared elsewhere in liverworts only with the mycotrophic subterranean axes of the allied genus Haplomitrium. The central strand in the thallus midrib has a unique histological organization and harbors an intra- and intercellular infection by a glomeromycotean fungus that is far more highly differentiated than most of the glomeromycotean associations described to date. The fungus enters the thallus via clefts in the ventral epidermis along the midrib and colonizes the parenchyma above, forming intracellular coils and prominent, relatively short-lived, hyphal swellings. Above the zone with intracellular colonization is a tissue area containing mucilage-filled intercellular spaces; here the fungus is entirely intercellular and forms abundant pseudoparenchymatous structures and, in more mature parts of the thalli, large hyphae with thick multistratose walls. Mucilage in Treubia differs in histochemistry and origin from that produced by apical papillae, via hypertrophied Golgi, in all other bryophytes. Remarkable parallels between fungal associations in Treubia, Haplomitrium, and Lycopodium, all members of very ancient lineages, suggest that these associations epitomize very early stages in the evolution of glomeromycotean symbioses.

Key Words: arbuscular mycorrhiza • Bryophyta • Glomeromycota • Metzgeriidae • mucilage secretion • phylogeny • symbiosis • Treubia

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. I. Bidartondo and J. G. Duckett Conservative ecological and evolutionary patterns in liverwort-fungal symbioses Proc R Soc B, February 7, 2010; 277(1680): 485 - 492. [Abstract] [Full Text] [PDF]

				L. E. Graham, M. E. Cook, D. T. Hanson, K. B. Pigg, and J. M. Graham Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats Am. J. Botany, February 1, 2010; 97(2): 268 - 275. [Abstract] [Full Text] [PDF]

				S. Pressel, R. Ligrone, J. G. Duckett, and E. C. Davis A novel ascomycetous endophytic association in the rhizoids of the leafy liverwort family, Schistochilaceae (Jungermanniidae, Hepaticopsida) Am. J. Botany, May 1, 2008; 95(5): 531 - 541. [Abstract] [Full Text] [PDF]

				R. Ligrone, A. Carafa, E. Lumini, V. Bianciotto, P. Bonfante, and J. G. Duckett Glomeromycotean associations in liverworts: a molecular, cellular, and taxonomic analysis Am. J. Botany, November 1, 2007; 94(11): 1756 - 1777. [Abstract] [Full Text] [PDF]