Fungi are a major cause of plant diseases and are responsible for large-scale harvest failure in crops like maize and other cereals all over the world. Together with scientists from the Helmholtz Zentrum in Munich, Regine Kahmann, from the Max Planck Institute for Terrestrial Microbiology in Marburg, and Jan Schirawski, who is now based at the University of Gttingen, analysed the genetic make-up of Sporisorium reilianum, an important maize parasite. Based on a comparison with the genome of a related fungal species, they succeeded in identifying new genes that play an important role in maize infestation. (Science, December 10, 2010)
The smut fungi Ustilago maydis and Sporisorium reilianum are parasites that attack maize plants. Ustilago maydis causes a disease known as boil smut or common smut, which is characterized by large tumour-like structures on the leaves, cobs and male flowers in which the fungus proliferates and produces spores. Sporisorium reilianum also attacks maize plants; however, it infects the entire plant and its symptoms become manifested only in the male and female flowers. For this reason, it is also referred to as maize head smut.
Little has been known up to now as to how these pathogens cause disease. Four years ago, a team of scientists headed by the Marburg group succeeded in decoding the genome sequence of Ustilago maydis. They demonstrated that the genes, for a large number of completely new proteins secreted by the fungus, are arranged in groups on the chromosomes in so-called gene clusters. These proteins control the colonisation of the host plant.
Similar and yet different
The researchers were initially only able to demonstrate the presence of these proteins in Ustilago maydis. "However, we found it hard to imagine that these proteins, which play such a crucial role in maize infestation, should only be present in the genome of a single smut fungus. For this reason, we also sequence
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| Contact: Regine Kahmann kahmann@mpi-marburg.mpg.de 49-642-117-8501 Max-Planck-Gesellschaft Source:Eurekalert |