Agaricomycetes is presented in Table14.1a, b.
Saprotrophic taxa occur in all orders of Agar-
icomycetes, and ECM taxa occur in at least 13
orders. As many as 37 independent ECM
lineages have been estimated to occur in Agar-
icomycetes (Tedersoo et al. 2010 ; Rinaldi et al.
2008 ). It has been proposed that the ancestor of
Agaricomycetes might have been ECM, based
on the occurrence of ECM taxa in Sebacinales
(Weiß et al.2004b), but molecular clock ana-
lyses (see below) suggest that the group is much
older than potential ECM hosts, including Pina-
ceae (Floudas et al. 2012 ; Hibbett and Matheny
2009 ). Phylogenomic analyses suggest that the
common ancestor of Agaricomycetes possessed
multiple ligninolytic class II fungal peroxidases
(PODs) and other plant cell wall (PCW)-
decaying enzymes, implying that it was capable
of producing a white rot (in which both the
lignin and cellulose components of PCWs are
degraded) (Floudas et al. 2012 ; Ruiz-Duenas
et al. 2013 ). Wood decayers with multiple
PODs and enzymes capable of attacking crys-
talline cellulose occur in diverse lineages of
Agaricomycetes, and these may have retained
the plesiomorphic white-rot mode of saprotro-
phy. Multiple origins of brown rot (in which
lignin is not appreciably removed) in Polypor-
ales, Boletales, and Gloeophyllales and the evo-
lution of the ECM condition inLaccaria bicolor
(Agaricales) seem to be associated with
repeated losses of PODs and other PCW-
degrading enzymes. Ongoing genomic compar-
isons are showing that some saprotrophic
Agaricomycetes do not conform to the typical
models of either white rot or brown rot, includ-
ing wood decayers, such asSchizophyllum com-
muneandFistulina hepatica, and soil, litter,
and dung fungi, such asAgaricus bisporusand
Coprinopsis cinerea(Morin et al. 2012 ; Ohm
et al. 2010 ; Stajich et al. 2010 ). Similarly,
increased sampling of ECM genomes is reveal-
ing considerable diversity in genes encoding
PCW-degrading enzymes among indepen-
dently evolved symbiotic lineages (F. Martin
and colleagues, unpublished).Table 14.1aNutritional modes in Agaricomycete orders, with examplar genera (Saprotrophsa)
White rot Brown rot Other/uncertainbAgaricales Pleurotus Fistulina Coprinopsis
Boletales Serpula
Amylocorticiales Plicaturopsis Anomoporia
Atheliales Athelopsis Athelopsis
Lepidostromatales
Polyporales Phanerochaete Postia
Russulales Stereum
Thelephorales Lenzitopsis
Gloeophyllales Gloeophyllum Boreostereum
Jaapiales Jaapia
Corticiales Punctularia
Hymenochaetales Trichaptum Bridgeoporus? Tubulicrinis
Trechisporales Sistotremastrum Porpomyces
Hysterangiales Phallogaster
Gomphales Lentaria Kavinia
Phallales Phallus
Geastrales Sphaerobolus Sclerogaster
Auriculariales Auricularia
Sebacinales Craterocolla
Cantharellales Sistotrema Botryobasidium
aBold = genome sequence of at least one species completed;? indicates uncertainty. Bacteriovores, algal and cyanobacterial
parasites, and animal pathogens are not included. For references, see this text and Hibbett and Thorn (2001). Some endophyte
observations by R. Gazis and R. Martin (unpublished)
bThis broad category includes saprotrophs on soil, litter, dung, and keratinic substrates, as well as wood decayers of uncertain rot
type or that do not correspond to classical white or brown rot definitions
384 D.S. Hibbett et al.