000 02293nab a2200265 a 4500
003 AR-ReUNN
005 20260702003303.0
008 260630s2006 ag |||||||||||||||||eng
041 0 _aeng
100 1 _aDuckett, Jeffrey G.
_9154262
700 1 _aCarafa, Anna
_9154263
700 1 _aLigrone, Roberto
_9154264
245 1 2 _aA highly differentiated glomeromycotean association with the mucilage-secreting, primitive antipodean liverwort Treubia (Treubiaceae): clues to the origins of mycorrhizas
264 1 _c2006
300 _a17 páginas
500 _aFot. byn., fot. col.
520 _aThallus 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.
650 4 _aMusgos
_9115152
650 4 _aMicorrizas
_9115569
650 4 _aAnatomia de la Planta
_97084
773 0 _tAmerican Journal of Botany
_x0002-9122
_gv. 93 n. 6 (2006)
_w238848
942 _cART
035 _a(IBONE)32875
001 238849
999 _c238849
_d238849
040 _aAR-ReUNN
_bspa
_cAR-ReUNN
_eaacr2