Isolates of Cercospora species from leaves displaying symptoms of grey leaf spot were collected in maize-producing areas of south-central Brazil in 2001 and 2002. Restriction digests of the internal transcribed spacer region of rDNA detected the presence of the same two Cercospora species described on maize in the United States, namely C. zeae-maydis and the recently described species, C. zeina...

The domestication of crops and the development of agricultural societies not only brought about major changes in human interactions with the environment but also in plants' interactions with the diseases that challenge them. We evaluated the impact of the domestication of maize from teosinte and the widespread cultivation of maize on the historical demography of Ustilago maydis, a fungal pathog...

The MAT region of Ustilago hordei, a bipolar barley pathogen, harbors distinct mating functions (a and b loci). Here, we show that the b locus is essential for mating and pathogenicity, and can induce pathogenicity when introduced into a strain carrying a b locus of opposite specificity. Transformation experiments using components of the a1 locus and analysis of resulting dual mating phenotypes...

The Ustilago maydis PYR3 gene encoding dihydroorotase activity was cloned by direct complementation of Escherichia coli pyrC mutations. PYR3 transformants of E. coli pyrC mutants expressed homologous transcripts of a variety of sizes and regained dihydroorotase activity. PYR3 also complemented Saccharomyces cerevisiae ura4 mutations, and again multiple transcripts were expressed in transformant...

The basidiomycete Ustilago maydis causes smut disease in maize, with large plant tumors being formed as the most prominent disease symptoms. During all steps of infection, U. maydis depends on a biotrophic interaction, which requires an efficient suppression of plant immunity. In a previous study, we identified the secreted effector protein Pit2, which is essential for maintenance of biotrophy ...

Fungal diseases of plants represent one of the most eminent threats to agriculture. Given the food needs of a growing world population and that more and more crops are devoted to fuel production, the necessity to develop crops with better resistance to disease is increasing. To accomplish this, the mechanisms that plant pathogenic fungi use to colonize plants need to be elucidated. As of now, t...

Stenocarpella maydis is the most prevalent ear rot pathogen of maize (Zea mays) in South Africa, the United States, and other countries. Infection and ultrastructure of propagules of S. maydis in maize were observed by light, scanning, and transmission electron microscopy. Two-celled conidia of S. maydis were found in the tissues of husk and kernels. Mycelia colonized inter- and intracellularly...

In Saccharomyces cerevisiae, the PMT, KRE2/MNT1, and MNN1 mannosyltransferase protein families catalyze the steps of the O-mannosylation pathway, sequentially adding mannoses to target proteins. We have identified members of all three families and analyzed their roles in pathogenesis of the maize smut fungus Ustilago maydis. Furthermore, we have shown that PMT4, one of the three PMT family memb...

SPECIFIC b ALLELES MATTER IN PHYTOPATHOGENIC USTILAGO MAYDIS Kavita Burman Aulakh