Tomato stands firm in face of fungus

Scientists at the University of Amsterdam have discovered how to keep one’s tomatoes from wilting – the answer lies at the molecular level. The story of how the plant beat the pathogen, and what it means for combating other plant diseases, is published May 9th in the open-access journal PLoS Pathogens.

Farmers and fellow agriculturalists are continuously battling the ability of plant pathogens to co-evolve alongside their host’s immune system. In agriculture, the most environmentally friendly way to combat the evolutionary change in plant diseases is to make use of the innate immune system of plants. Growers can cross into targeted plant varieties certain polymorphic resistance genes that occur in related plants, thereby naturally boosting the plant’s immune system.

In this study, Dr. Martijn Rep and his team explored the molecular basis of this previously established concept of crossing in resistance genes. The authors considered the interaction between a fungal pathogen, Fusarium oxysporum, and the tomato plant in which the fungus causes Fusarium wilt disease.

The group found that a small protein secreted by some strains of the fungus causes it to overcome two of the tomato’s disease resistance genes. However, a third resistance gene was shown to specifically target this suppressor protein, rendering the plant fully immune to any fungal strain that produces the protein. Thus, with the right set of resistance genes, tomatoes can beat the fungus despite the latter’s “molecular tricks.”

“This molecular analysis has revealed a hitherto unpredicted strategy for durable disease control based on resistance gene combinations,” say the authors.

PLEASE ADD THIS LINK TO THE PUBLISHED ARTICLE IN ONLINE VERSIONS OF YOUR REPORT: http://www.plospathogens.org/doi/ppat.1000061 (link will go live on Friday, May 9)

CITATION: Houterman PM, Cornelissen BJC, Rep M (2008) Suppression of Plant Resistance Gene-Based Immunity by a Fungal Effector. PLoS Pathog 4(5): e1000061. doi:10.1371/journal.ppat.1000061

PRESS-ONLY PDF: http://www.plos.org/press/plpa-04-05-09-rep.pdf

CONTACT:
Dr. Martijn Rep
m.rep@uva.nl
+31-20-5257764

This press release refers to an upcoming article in PLoS Pathogens. The release is provided by journal staff. Any opinions expressed in these releases or articles are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.

PLoS Pathogens (www.plospathogens.org) publishes outstanding original articles that significantly advance the understanding of pathogens and how they interact with their host organisms. All works published in PLoS Pathogens are open access. Everything is immediately available subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.