This week, an article appears in 'Nature Plants', written by scientists of Wageningen University and The Sainsbury Laboratory in Norwich (Great Britain), in which they report having discovered a new gene against the phytophthora potato blight in a South American wild potato. That gene provides a previously unseen defence mechanism against the feared disease. The gene triggers an immune response against elicitin, a 'conserved' protein with an important biological function. This way, it becomes less probable for the pathogen to adapt in order to circumvent the immune response.
Vivianne Vleeshouwers, breeding researcher at Wageningen University, is one of the leading scientists within the team that has achieved this important breakthrough. Vleeshouwers: "We have identified a gene that's responsible for a completely new protection mechanism in wild potato varieties. We hope this new knowledge will aid in fighting potato blight."
Serious threat to food production
Phytophthora infestans, the cause of potato blight that leads to significant damage at potato farmers worldwide, is also the infamous cause of the Irish famine in the nineteenth century. The globally dispersed pathogen still poses a serious threat to food production. The international team of scientists studied wild members of the Solanum family, which the potato is part of, looking for genes that respond to elicitins. These are so-called 'conserved' proteins of the potato blight pathogen. Vleeshouwers: "These proteins hardly change over time and during diversification of varieties and strains. That's because the proteins play a crucial role in phytophthora's life cycle, and they were optimized during previous evolution. By finding a potato gene that tackles these types of proteins, we lower the chance of the pathogen being able to break through the new resistance."10 year search
After a 10 year search, the scientists have found such a gene, called ELR (Elicitin Response), which codes for a receptor-like protein in Solanum microdontum. In plants, many of these types of receptors are on the outside of the plant cell, thus forming the first line of defence. This protection mechanism looks like a series of antennae, each one tuned to a different conserved attributed of the intruding pathogens.
ELR gene
The simultaneous presence of the ELR gene and elicitin leads to cell death at the spot where phytophthora infects the plant, thus forming an immune system that stops the spread of the pathogen. Introducing the ELR gene in cultivated potato plants makes the plants less susceptible to various strains of the potato blight.
The results come from fundamental scientific research, and are thus still in the research stage. In the long run, the finding will open up new possibilities for developing resistance that works in a broad and long-term manner. That resistance could aid in increasingly environmentally friendly cultivation of potatoes across the world, and providing improved food security.
source: WageningenUR
source: WageningenUR