We have shown that Ca(II) ions, ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid, LaCl3, and six known calmodulin inhibitors shift the yeast-mycelium dimorphic potential of Ceratocystis ulmi. Our data are consistent with the conclusions that Ca(II)-calmodulin interaction is necessary for mycelial growth in C. ulmi and that the absence of this interaction leads to the yeast phase.

The Chinese species Cryptococcus ulmi Tang & Hao is found to be distantly related to other sampled Cryptococcus species based on both molecular and morphological study. A new felt scale genus, Macroporicoccus Nan & Wu gen. n., is erected therefore for C. ulmi. The new genus differs from other eriococcid genera due to the presence of large simple pores, here referred to as macrodisc pores. The a...

The emergence of new microbial pathogens can result in destructive outbreaks, since their hosts have limited resistance and pathogens may be excessively aggressive. Described as the major ecological incident of the twentieth century, Dutch elm disease, caused by ascomycete fungi from the Ophiostoma genus, has caused a significant decline in elm tree populations (Ulmus sp.) in North America and ...

The ascomycete fungus Ophiostoma novo-ulmi is responsible for the pandemic of Dutch elm disease that has been ravaging Europe and North America for 50 years. We proceeded to annotate the genome of the O. novo-ulmi strain H327 that was sequenced in 2012. The 31.784-Mb nuclear genome (50.1% GC) is organized into 8 chromosomes containing a total of 8,640 protein-coding genes that we validated with...

Fungal dimorphism is a complex trait and our understanding of the ability of fungi to display different growth morphologies is limited to a small number of model species. Here we study a highly aggressive dimorphic fungus, the ascomycete Ophiostoma novo-ulmi, which is a model in plant pathology and the causal agent of Dutch elm disease. The two growth phases that this fungus displays, i.e., a y...

We studied the inoculum size effect in Ceratocystis ulmi, the dimorphic fungus that causes Dutch elm disease. In a defined glucose-proline-salts medium, cells develop as budding yeasts when inoculated at > or = 10(6) spores per ml and as mycelia when inoculated at <10(6) spores per ml. The inoculum size effect was not influenced by inoculum spore type, age of the spores, temperature, pH, oxygen...

The root-knot nematode Meloidogyne ulmi is synonymised with Meloidogyne mali based on morphological and morphometric similarities, common hosts, as well as biochemical similarities at both protein and DNA levels. M. mali was first described in Japan on Malus prunifolia Borkh.; and M. ulmi in Italy on Ulmus chenmoui W.C. Cheng. Morphological and morphometric studies of their holo- and paratypes ...