Plants have an immune system that resists infection, yet 10% of the world's agricultural production is lost annually to diseases caused by bacteria, fungi, and viruses. Understanding how disease resistance works may help combat this scourge.
In a new study published online this week in the open-access journal PLoS Biology, Tessa Burch-Smith, Savithramma Dinesh-Kumar, and colleagues show how one aspect of the plant immune system is defined by the gene-for-gene hypothesis: a plant Resistance (R) gene encodes a protein that specifically recognizes and protects against one pathogen or strain of a pathogen carrying a corresponding Avirulence (Avr) gene.
In tobacco and its relatives, the N resistance protein confers resistance to infection by the Tobacco mosaic virus (TMV). The authors used N, and the TMV Avirulence gene, p50, to investigate the mechanism of gene-for-gene resistance. Contrary to current models, which propose that recognition of resistance genes occurs solely through their leucine-rich repeat domain, the authors show that association is mediated by a completely different region on N's Toll-interleukin-1 receptor homology domain, which is structurally similar to animal innate immunity molecules. These findings provide novel insights into how R proteins recognize pathogen Avr proteins and should help in long-term efforts to enhance crop yield.
Citation: Burch-Smith TM, Schiff M, Caplan JL, Tsao J, Czymmek K, et al. (2007) A novel role for the TIR domain in association with pathogen-derived elicitors. PLoS Biol 5(3): e68. doi:10.1371/journal.pbio.0050068.
CONTACT:
Savithramma Dinesh-Kumar
Yale University
219 Prospect Street
New Haven, CT 06520
+1-203 432-9965
+1-203 432-6161 (fax)
savithramma.dinesh-kumar@yale.edu
PLEASE MENTION THE OPEN-ACCESS JOURNAL PLoS BIOLOGY (www.plosbiology.org) AS THE SOURCE FOR THESE ARTICLES AND PROVIDE A LINK TO THE FREELY-AVAILABLE TEXT. THANK YOU.
All works published in PLoS Biology are open access. Everything is immediately available—to read, download, redistribute, include in databases, and otherwise use—without cost to anyone, anywhere, 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.
Journal
PLoS Biology