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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROL OF TOXIC ENDOPHYTIC FUNGI WITH BACTERIAL ENDOPHYTES AND REGULATION OF BACTERIAL METABOLITES FOR NOVEL USES IN FOOD SAFETY

Location: Toxicology and Mycotoxin Research

Title: Deletion of the Ustilago maydis ortholog of the Aspergillus sporulation regulator medA affects mating and virulence through pheromone response

Authors
item Chacko, Nadia -
item Gold, Scott

Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 11, 2012
Publication Date: April 19, 2012
Repository URL: http://naldc.nal.usda.gov/download/55255/PDF
Citation: Chacko, N., Gold, S.E. 2012. Deletion of the Ustilago maydis ortholog of the Aspergillus sporulation regulator medA affects mating and virulence through pheromone response. Fungal Genetics and Biology. 49:426-432. dx.doi.org/10.1016/j.fgb.2012.04.002

Interpretive Summary: Mating of compatible haploid cells of Ustilago maydis (the causal agent of common smut of corn) is essential for infection and disease development in the plant host, maize. For mating and subsequent filamentous growth and pathogenicity, the pheromone responsive transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regulators like rop1 and hap1. Here we describe the identification of another putative Prf1 regulator, med1, the ortholog of the Aspergillus nidulans medusa (medA) transcription factor and show that it is required for mating and full virulence in U. maydis. med1 deletion mutants show both pre- and post-mating defects and are unresponsive to external pheromone. The expression of prf1 is down-regulated in deltamed1 compared to the wild type, suggesting that med1 is a positive regulator and is upstream of prf1. Additionally, indicative of a role in secondary metabolism regulation, deletion of the med1 gene de-represses the production of glycolipids in U. maydis.

Technical Abstract: Mating of compatible haploid cells of Ustilago maydis is essential for infection and disease development in the host. For mating and subsequent filamentous growth and pathogenicity, the transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regulators like rop1 and hap1. Here we describe the identification of another putative Prf1 regulator, med1, the ortholog of the Aspergillus nidulans medusa (medA) transcription factor and show that it is required for mating and full virulence in U. maydis. med1 deletion mutants show both pre- and post-mating defects and are unresponsive to external pheromone. The expression of prf1 is down-regulated in deltamed1 compared to the wild type, suggesting that med1 is upstream of prf1. Additionally, indicative of a role in secondary metabolism regulation, deletion of the med1 gene de-represses the production of glycolipids in U. maydis.

Last Modified: 4/19/2014
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