Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans.

Nature
Authors
Keywords
Abstract

Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement. To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population. Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion. Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars. Here we report the sequence of the P. infestans genome, which at approximately 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for approximately 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.

Year of Publication
2009
Journal
Nature
Volume
461
Issue
7262
Pages
393-8
Date Published
2009 Sep 17
ISSN
1476-4687
URL
DOI
10.1038/nature08358
PubMed ID
19741609
Links
Grant list
BB/E007120/1 / Biotechnology and Biological Sciences Research Council / United Kingdom
BB/G015244/1 / Biotechnology and Biological Sciences Research Council / United Kingdom
BBS/B/07152 / Biotechnology and Biological Sciences Research Council / United Kingdom
G0400284 / Medical Research Council / United Kingdom