Crop Biotech Update

The Evolution of Potato Blight Pathogen

December 10, 2010

Researchers at Sainsbury Laboratory, UK have traced the key genetic clues that facilitated Phytophthora infestans, the fungus-like microorganism that caused the 1845 Irish potato famine, to transfer from wild plant hosts to cultivated potatoes.

Plant pathologist Sophien Kamoun and her team identified the key genes by comparing the genome of potato blight pathogen with other four sister species. Results reveal common ‘housekeeping' genes, including that of spore generation, but there are also several regions with non-coding repeated DNA sequences. These regions have fewer genes, but most are responsible for pathogenicity, blocking host immunity and destroying host cell walls. These genes are varied among the species, either in terms of sequence and amount of copies present.

According to the scientists, the variation suggests that the regions are engaged in evolution and adaptation of the pathogen to new hosts. Results of the study could be used in the development of fungicides and disease-resistant potato varieties.

Read the abstract of this study at http://www.sciencemag.org/content/330/6010/1540.abstract?sid=e7464d18-b8c8-4372-b837-949cbb82e10e,