KNOXVILLE, Tenn. A new commentary on the nature of pathogens is raising startling new questions about the role that fundamental science research on evolution plays in the understanding of emerging disease.
Ecological speciation, and specifically speciation that occurs when a subset of a population shifts onto a novel host, is one of the main routes for the emergence of new fungal diseases in plants, argue the authors of a new paper published online in Trends in Ecology & Evolution (TREE).
Linking emerging diseases with ecological speciation has important implications for understanding the biological mechanisms of disease and for designing more efficient and sustainable control programs, say Tatiana Giraud and Pierre Gladieux, both researchers at Universite Paris-Sud, and Sergey Gavrilets, associate director for scientific activities at the National Institute for Mathematical and Biological Synthesis and a professor at the University of Tennessee-Knoxville.
While much attention has been given toward extrinsic factors that might contribute to emerging fungal diseases, such as climate change or worldwide trade, the authors contend, intrinsic genetic changes in the pathogen itself should also be considered.
The authors point out that certain life-history features of fungal plant pathogens make them prone to rapid ecological speciation by host shifts, including strong disruptive selection caused by hosts, a large number of spores produced by pathogens, mating within hosts, a small number of genes underlying the specificity of host-pathogen interactions, and frequent asexual reproduction with rare occurrences of sexual recombination.
Fungi account for 30 percent of emerging infectious diseases in plants. These fungal diseases can radically alter natural ecosystems as well as food and agricultural production. Examples include the chestnut blight fungus, which eliminated nearly 100 percent of native chestnut trees throughout eas
|Contact: Catherine Crawley|
National Institute for Mathematical and Biological Synthesis (NIMBioS)