Formidable Fungal Force Counters Biofuel Plant Pathogens

Rusts are a major disease of plants, particularly cereals that can cause huge losses in the crop industry. They are also sources of enzymes that can be used in degrading biomass for biofuel production. Two groups of international researchers have studied two rust fungi to identify the characteristics by which pathogens can invade their plant hosts as well as to develop methods in controlling them.

The poplar leaf rust was studied by INRA scientists and the wheat and barley stem rust by scientists in Massachusetts Institute of Technology, Harvard University, University of Minnesota, and U.S. Department of Agriculture. The paper published in the Proceedings of the National Academy of Sciences describes a two-pronged attack by the fungi to mask their proximity to the plant and then use enzymes to attach the fungal cell wall to the plant cell wall during invasion. In addition, by using effectors, fungus can suppress host defense and recognition.

"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," said Sébastien Duplessis from INRA.

Details of the article can be viewed at http://www.jgi.doe.gov/News/news_11_05_03.html.