A South American wild relative of cultivated potatoes is the source of a gene that increases resistance against potato late blight. In a recent issue of Nature Plants, researchers from Wageningen University in the Netherlands and the Sainsbury Laboratory in Norwich, UK, indicate the gene targets elicitin, a protein with a biological function that makes it less likely the pathogen will evade resistance.
According to Vivianne Vleeshouwers, a breeding research expert at Wageningen University, who is one of the leading scientists in the team says: “We identified a gene responsible for a totally new line of defense in wild relatives of potato. We hope that this will help us to tackle late blight.”
Phytophthora infestans, the pathogen that causes potato late blight disease, is still a major threat to crops worldwide. According to a news release, the international team of scientists searched the germplasm of wild members of the Solanum family (which includes potato) for genes that responded to elicitins, so called “conserved” proteins from the blight pathogen.
“These proteins hardly change in time and during species diversification because their role is crucial and their composition has been optimized during earlier evolution,” Vleeshouwers says.
“Resistance enhanced by action against this type of pathogen proteins would make it less likely that the pathogen will evolve to overcome the resistance.”
Potato late blight, caused by the destructive Irish famine pathogen Phytophthora infestans, is a major threat to global food security1,2. All late blight resistance genes identified to date belong to the coiled-coil, nucleotide-binding, leucine-rich repeat class of intracellular immune receptors3. However, virulent races of the pathogen quickly evolved to evade recognition by these cytoplasmic immune receptors4. Here we demonstrate that the receptor-like protein ELR (elicitin response) from the wild potato Solanum microdontum mediates extracellular recognition of the elicitin domain, a molecular pattern that is conserved in Phytophthora species. ELR associates with the immune co-receptor BAK1/SERK3 and mediates broad-spectrum recognition of elicitin proteins from several Phytophthora species, including four diverse elicitins from P. infestans. Transfer of ELR into cultivated potato resulted in enhanced resistance to P. infestans. Pyramiding cell surface pattern recognition receptors with intracellular immune receptors could maximize the potential of generating a broader and potentially more durable resistance to this devastating plant pathogen.