Still, one of the goals of the project is to be able to determine how to disrupt the effectors by which the fungus can suppress host defense and recognition. In the paper, the team describes a two-pronged attack where the fungi mask their proximity to the plant and then use enzymes to attach the fungal cell wall to the plant cell wall and then invade the host.
"The precise analysis of these effectors, their localization and their targets in the host plant, and how they evolve to overcome plant resistances will contribute to the selection and management of sustainable resistances of poplar trees to the rust disease," said Duplessis.
He said the researchers plan to sequence more Melampsora genomes to better understand the process by which the rust fungus adapts to its host and overcome the plant's resistance. "Our paper demonstrates that the rust fungi genomes contain more than a thousand of such small effectors that likely interfere with plant perception systems and activation of defense reactions. Thus a targeted approach to disrupt the effectors entry and action might be complicated. However, sequencing the rust fungus genome opens great perspectives to study the evolution of these candidate effectors and further define new resistances through breeding strategies in tree plantations."
"With these blueprints we can then go and analyze at a population biology level the genetic diversity of pathogens as they evolve and adapt to control agents such as fungicides to develop more coordinated management strategies," said Pietro Spanu, a molecular plant biologist at Imperial College London who studies a mildew that is also a fungal pathogen. "The genome sequences are really toolkits," he said. "They give us lots of information on how the organisms evolved, allowing us to make hypotheses on what fungi need to become obligate parasites."
Spanu also said that the paper is part of a recent spate in genome publications on these fungi, a
|Contact: David Gilbert|
DOE/Joint Genome Institute