In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results ...

Understanding the routes of pathogen introduction contributes greatly to efforts to protect against future disease emergence. Here, we investigated the history of the invasion in North America by the fungal pathogen Microbotryum lychnidis-dioicae, which causes the anther smut disease on the white campion Silene latifolia. This system is a well-studied model in evolutionary biology and ecology o...

Despite important advances in the last few years, the evolution of reproductive isolation (RI) remains an unresolved and critical gap in our understanding of speciation processes. In this study, we investigated the evolution of RI among species of the parasitic fungal species complex Microbotryum violaceum, which is responsible for anther smut disease of the Caryophyllaceae. We found no evidenc...

The generic position of the enigmatic smut fungus Ustilago solida is evaluated applying molecular phylogenetic analyses using ITS and LSU rDNA sequences as well as light and scanning electron microscopical investigations of several collections of this species. Ustilago solida has previously been included in five different genera (Ustilago, Urocystis, Sorosporium, Cintractia, and Tolyposporium),...

Host ecological traits may limit exposure to infectious disease, thereby generating the wide variation in disease incidence observed between host populations or species. The exclusion of disease by ecological traits may then allow selection to act against physiological defenses when they are costly to maintain in the absence of disease. This study investigates ecological resistance in the Silen...

Ustilaginoidins are bis-naphtho-γ-pyrone mycotoxins isolated from the rice false smut balls (FSBs) infected by the pathogen Villosiclava virens in rice spikelets on panicles. In order to obtain large amounts of pure ustilaginoidins to further evaluate their biological activities and functions, phytotoxicity on rice, security to human and animals as well as to accelerate their applications as ph...

It is well known that diseases can greatly influence the morphology of plants, but often the incidence of disease is either too rare or the symptoms too obvious for the 'abnormalities' to cause confusion in systematics. However, we have recently come across several misinterpretations of disease-induced traits that may have been perpetuated into modern species inventories. Anther-smut disease (c...

Resistance to systemic diseases is often difficult to measure quantitatively because individuals can be scored only as either diseased or healthy. A technique is described for cloning individuals of Silene vulgaris plants using the tissue culture of seedling meristems. Inoculation of such clonally replicated genotypes within two families shows that segregation of resistance to anther-smut disea...

Stripe smut of grasses, Ustilago striiformis s.l., is a complex of smut fungi widely distributed over temperate and subtropical regions. The disease results in the shredding and death of leaf tissue following the rupture of elongated sori. Nearly 100 different grass species in more than 30 genera are infected by stripe smut. During the last two centuries more than 30 smut taxa have been describ...

Smut fungi are well-suited to investigate the ecology and evolution of plant pathogens, as they are strictly biotrophic, yet cultivable on media. Here we report the genome sequence of Melanopsichium pennsylvanicum, closely related to Ustilago maydis and other Poaceae-infecting smuts, but parasitic to a dicot plant. To explore the evolutionary patterns resulting from host adaptation after this h...