Rhystidhysteron rufulum is a poorly known mainly
saprobic species capable of utilizing different substrata and
occupying diverse habitats. It can also be associated with plant
disease and occurs on the wood of living or dead dicotyledonous
plants including stem cankers of citrus. It produces
superficial ascocarps (sexual structures) that are darkly pigmented
and elongated with a longitudinal slit. Upon maturity, the
ascocarp opens to form an irregular cup from which sexual spores
are released. The sexual spores are darkly pigmented with
rare muriform (longitudinal and horizontal) septations. Due
to its differences in ascocarp development and morphology from
other hysteriaceous fungi Rhytidhysteron rufulum was
traditionally classified in Patellariales (Dothideomycetes), but
recent molecular phylogenetic analyses of multiple nuclear loci
support it as being a member of the Hysteriales and closely related
to the saprobic Hysterium pulicare (Boehm et al.
2009).
Dothideomycetes is the largest class of ascomycete fungi and
contain species with diverse ecologies and nutritional modes,
including plant pathogens, insect pathogens, lichens, marine fungi
and saprobes. Two large orders contain the majority of economically
important plant pathogens and Hysteriales is the sister order to
one of them, the Pleosporales. Current phylogenetic hypotheses
support a saprobic nutritional mode as ancestral in the class with
multiple derivations of pathogens, autotrophic symbioses and unique
life styles (Schoch et al 2009). The genome of R. rufulum,
along with those from other saprobic taxa, will allow a greater
understanding of the metabolic diversity of Dothideomycetes and the
genomic diversifications associated with shifts between major
ecologies and nutritional modes.
References:
Boehm, E.W.A., Mugambi, G.K., Miller, A.N., Huhndorf, S.M.,
Marincowitz, S., Spatafora, J.W. and C.L. Schoch. 2009. A
molecular phylogenetic reappraisal of the Hysteriaceae,
Mytilinidiaceae and Gloniaceae (Pleosporomycetidae,
Dothideomycetes) with keys to world species. Studies in Mycology
64: 49-84.
Schoch, C.L., Crous, P.W., Groenewald, J.Z., Boehm, E.W.A.,
Burgess, T.I., De Gruyter, J., De Hoog, G.S., Dixon, L.J., Grube,
M., Gueidan, C., Harada, Y., Hatakeyama, S., Hirayama, K., Hosoya,
T., Huhndorf, S.M., Hyde, K.D., Jones, E.B.G., Kohlmeyer, E.B.G.,
Kruys, Å., Lücking, R., Lumbsch, H.T., Marvanová,
L., Mbatchou, J.S., McVay, A.H., Miller, A.N., Mugambi, G.K.,
Muggia, L., Nelsen, M.P., Nelson, P., Owensby, C A., Phillips,
A.J.L., Phongpaichit, S., Pointing, S.B., Pujade-Renaud, V., Raja,
H.A., Rivas Plata, E., Robbertse, B., Ruibal, C., Sakayaroj, J.,
Sano, T., Selbmann, L., Shearer, C.A., Shirouzu, T., Slippers, B.,
Suetrong, S., Tanaka, K., Volkmann-Kohlmeyer, B., Wingfield, M.J.,
Wood, A.R., Woudenberg, J.H.C., Yonezawa, H., Zhang, Y. and J.W.
Spatafora. 2009. A class-wide phylogenetic assessment of
Dothideomycetes. Studies in Mycology 64: 1-15.
Genome Reference(s)
Ohm RA, Feau N, Henrissat B, Schoch CL, Horwitz BA, Barry KW, Condon BJ, Copeland AC, Dhillon B, Glaser F, Hesse CN, Kosti I, LaButti K, Lindquist EA, Lucas S, Salamov AA, Bradshaw RE, Ciuffetti L, Hamelin RC, Kema GH, Lawrence C, Scott JA, Spatafora JW, Turgeon BG, de Wit PJ, Zhong S, Goodwin SB, Grigoriev IV
Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi.
PLoS Pathog. 2012;8(12):e1003037. doi: 10.1371/journal.ppat.1003037