Tilletiopsis washingtonensis (MCA4186)
The genus Tilletiopsis Derx was first described based on morphological characteristics that resembled certain Tilletia species (Derx, 1948). Later, the original strain was no longer available, so Tilletiopsis washingtonensis Nyland was designated as a neotype (Nyland, 1950) for the genus. The fungus forms cream to tan yeast-like colonies on agar media. These colonies consist of mycelium producing ballistospores by budding. Hyaline chlamydospores may be formed in older cultures (Nyland, 1950). The strain selected for genome sequencing was isolated from the phylloplane of a Geranium leaf.
Phylogenetic analyses of rDNA loci among ustilaginomycetous anamophic fungi show that T. washingtonensis belongs to Entylomatales (Begerow and Bauer, 2000; Begerow et al., 2002). This fungus was initially recognized as a non-phytopathogenic yeast based on several studies in which it was found on the surface of healthy plants (Nyland, 1950; Urquhart and Punja, 2002). Tilletiopsis washingtonensis has also been isolated from air (Marchisio et al., 1992). In addition to being an epiphytic yeast, there were several trials of using T. washingtonensis as a biocontrol agent against powdery mildew disease on cucumbers (Urquhart et al., 1994; Urquhart and Punja, 2002). However, current studies reported that T. washingtonensis and other certain Tilletiopsis species were a major cause of white haze postharvest disorder of apples in Europe (Boekhout et al., 2006; Baric et al., 2010).
The genome sequence of T. washingtonensis will provide the first whole genome reference sequence for a member of Entylomatales. Researchers will use these data in phylogenetic and phylogenomic reconstructions and in comparative genomics studies that seek to elucidate the molecular bases governing production of sexual and anamorphic states and the evolution of phytopathogenicity in Ustilaginomycotina.
Tilletiopsis washingtonensis culture on potato dextrose agar. Bar = 2.5 mm. Photo: Teeratas Kijpornyongpan.
References:
Baric S, Lindner L, Marschall K, Dalla Via J. 2010. Haplotye diversity of Tilletiopsis spp. causing white haze in apple orchards in Northern Italy. Plant Pathology 59:535–541.
Begerow D, Bauer R. 2000. Phylogenetic placements of ustilaginomycetous anamorphs as deduced from nuclear LSU rDNA sequences. Mycological Research 104(1):53–60.
Begerow D, Lutz M, Oberwinkler F. 2002. Implications pf molecular characters for the phylogeny of the genus Entyloma. Mycological Research 106(12):1392–1399.
Boekhout T, Gildemacher P, Theelen B, Müller WH, Heijne B, Lutz M. 2006. Extensive colonization of apples by smut anamorphs causes a new postharvest disorder. FEMS Yeast Research 6:63–76.
Derx HG. 1948. Itersonilia nouveau genre de Sporobolomycètes à mycélium bouclé. Bulletin of Botanical Garden Buitenzorg Series III 17(4):465–472.
Marchisio V, Nosenzo C, Caramiello R. 1992. Preliminary survey of airborne fungal propagules in Turin, Italy. Mycological Research 96(7):535–541.
Nyland G. 1950. The Genus Tilletiopsis. Mycologia 42(4):487–496.
Urquhart EJ, Menzies JG, Punja ZK. 1994. Growth and biological control activity of Tilletiopsis species against powdery mildew (Sphaerotheca fuliginea) on greenhouse cucumber. Phytopathology 84(4):341–351.
Urquhart EJ, Punja ZK. 2002. Hydrolytic enzymes and antifungal compounds produced by Tilletiopsis species, phyllosphere yeasts that are antagonists of powdery mildew fungi. Canadian Journal of Microbiology 48:219–229.
Genome Reference(s)
Kijpornyongpan T, Mondo SJ, Barry K, Sandor L, Lee J, Lipzen A, Pangilinan J, LaButti K, Hainaut M, Henrissat B, Grigoriev IV, Spatafora JW, Aime MC
Broad Genomic Sampling Reveals a Smut Pathogenic Ancestry of the Fungal Clade Ustilaginomycotina.
Mol Biol Evol. 2018 Aug 1;35(8):1840-1854. doi: 10.1093/molbev/msy072