Let there be blight: functional analysis of virulence in Phytophthora infestans

School of Biological and Chemical Sciences, University of Exeter, Washington Singer Laboratories, Perry Road, Exeter EX4 4QG, UK.
Molecular Microbiology (Impact Factor: 4.42). 03/2004; 51(4):913-5. DOI: 10.1046/j.1365-2958.2003.03878.x
Source: PubMed


An article in this issue of Molecular Microbiology demon- strates that a G-protein α -subunit plays diverse roles in pathogenesis-related development of the oomycete pathogen Phytophthora infestans . This report not only identifies one of the key signalling pathways involved in regulating the activity of motile zoospores and appresso- rium-mediated plant infection, but also validates the use of homology-dependent gene silencing as a method for studying virulence in oomycete pathogens. The genus Phytophthora contains some of the world's most economically important and devastating pathogen species. Among these are the causes of important dis- eases of soybeans, oil palms, cocoa, numerous tree spe- cies (including oak, which suffers from the currently significant sudden death disease), as well as cucumbers and strawberries (Rizzo et al ., 2002; van West et al ., 2003). Of all the Phytophthora diseases, however, the one that everyone who has ever lifted a plant pathology text book knows about is potato late blight, caused by Phy- tophthora infestans . This was the disease responsible for causing the Irish potato famine in the 1840s, a humani- tarian disaster with very considerable long-term socioeco- nomic consequences, some of which are still apparent even today (Donnelly, 1996; Braa, 1997). But this disease is not simply a historical footnote - it is still widespread throughout potato-growing regions of the world, and it is virtually impossible to grow potatoes effectively in temper- ate climates without some form of late blight disease con- trol. The persistence of late blight as a problem, coupled with the difficulty of breeding for durable disease resis- tance in the host, means that understanding the biology of P. infestans is of paramount importance, not only as a means of developing the next generation of chemicals with which to control the disease, but also in the hope of developing completely novel means of disease control

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