Functional genomics in the potato late blight pathogen

2007 Impact statement
  • Fry, William Earl

abstract

We have discovered viruses in the pathogen (Phytophthora infestans) that causes the late blight disease of potatoes and tomatoes. We have demonstrated that at least one of these viruses is amenable to manipulation in the lab, so that it has potential to be used as a gene expression or gene silencing vector – in a manner analogous to the phenomenon known as Virus Induced Gene Silencing (VIGS) in plants. This technology is important because there currently is no available method for efficient analysis of the sequenced genome of this pathogen. Without a more efficient method of analysis of its genome, progress in learning the basic life secrets of this very important pathogen, and, hence, developing innovative control procedures effective in agriculture, will be severely constrained.

submitted by

issue being addressed

Potato late blight is caused by the pathogen Phytophthora infestans, and it has devastated potato crops since it was first discovered as the disease that led to the Irish potato famine. To date, potatoes are grown only using massive amounts of fungicide (2000 tons annually in the USA) to protect them from this disease. The many attempts to construct resistant plants using classical R genes have failed because the pathogen is so highly mutable. Thus we need to understand the basic biology of the organism to construct disease suppression technologies that will be more durable. In recognition of its importance, the genome of this organism has recently been sequenced, but analysis of the genome is severely constrained because there is no technology for efficiently analyzing the function of genes detected in the sequence. Transformation is very inefficient. An attractive alternative is to use viruses as gene expression or gene silencing vectors. Our goal is to develop recently discovered viruses in P. infestans.

response

We have discovered viruses in the potato late blight pathogen. This is the first report of viruses in this pathogen and at least some of the viruses represent novel families, previously unknown to science. One of these viruses appears amenable to manipulation in functional genomics (functional analysis of genes discovered in the genome sequence). We have modified the virus to demonstrate that it can be used for gene expression in this organism. Because this discovery is so new, others have not yet had opportunity to employ the technique, but other scientists working on this group of organisms have already requested virus vectors as soon as we develop them.

impact assessment

At this point, the major impact is on the community of scientists who work on this pathogen. Eventually, we hope the impact will expand to other biological scientists and finally to production agriculture.

academic priority area

has geographic focus

funding source description

  • College of Agriculture and Life Sciences at Cornell
  • Hatch

mission focus

From CALS annual faculty reporting. Imported on August 5, 2008