IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Sebacinales are common mycorrhizal associates of Ericaceae
Autor/es:
SELOSSE, M-A., S. SETARO, F. GLATARD, F. RICHARD, C. URCELAY & M. WEISS.
Revista:
NEW PHYTOLOGIST
Referencias:
Año: 2007 vol. 174 p. 864 - 878
ISSN:
0028-646X
Resumen:
Previous reports of sequences of Sebacinales (basal Hymenomycetes) from ericoid
mycorrhizas raised the question as to whether Sebacinales are common mycorrhizal
associates of Ericaceae, which are usually considered to associate with ascomycetes.
Here, we sampled 239 mycorrhizas from 36 ericoid mycorrhizal species across the
world (Vaccinioideae and Ericoideae) and 361 mycorrhizas from four species of basal
Ericaceae lineages (Arbutoideae and Monotropoideae) that do not form ericoid
mycorrhizas, but ectendomycorrhizas. Sebacinales were detected using sebacinoidspecific
primers for nuclear 28S ribosomal DNA, and some samples were investigated
by transmission electron microscopy (TEM).
Diverging Sebacinales sequences were recovered from 76 ericoid mycorrhizas,
all belonging to Sebacinales clade B. Indeed, some intracellular hyphal coils had
ultrastructural TEM features expected for Sebacinales, and occurred in living cells.
Sebacinales belonging to clade A were found on 13 investigated roots of the basal
Ericaceae, and TEM revealed typical ectendomycorrhizal structures.
Basal Ericaceae lineages thus form ectendomycorrhizas with clade A Sebacinales,
a clade that also harbours ectomycorrhizal fungi. This further supports the proposition
that Ericaceae ectendomycorrhizas involve ectomycorrhizal fungal taxa.
When ericoid mycorrhizas evolved secondarily in Ericaceae, a shift of mycobionts
occurred to ascomycetes and clade B Sebacinales, hitherto not described as ericoid
mycorrhizal fungi