Crop-killing pathogen found to disable plants’ alarm system
Scientists from The James Hutton Institute, working in collaboration with the University of York and Université Libre de Bruxelles, have discovered how one of the world’s most destructive plant diseases manages to slip past crops’ defences – a breakthrough that could help farmers grow stronger, more resilient plants.
The new research, published in Nature Communications, describes a family of enzymes produced by a microorganism called Phytophthora infestans, a recurrent threat to potato and tomato crops worldwide.
The team discovered that this pathogen employs special enzymes, called AA7 oxidases, to disable the plants’ early warning system, weakening their defences before they have time to respond, and that disabling the genes that encode these enzymes rendered the pathogen incapable of infecting the host.
The Hutton is a world leading research institute addressing the issue of global food security by finding scientific solutions for the sustainable management of land and natural resources and the demands for improved agricultural productivity and crop resilience.
“We need better strategies for protecting our food if we are to secure global food supplies in the future, and this latest discovery is a real step forward in doing that. These enzymes are conserved across major plant pathogens, and their discovery paves the way for powerful new strategies in crop protection.”
Dr. Stephen Whisson, Molecular Potato Pathologist
Dr Federico Sabbadin, from the University of York’s Centre for Novel Agricultural Products (CNAP), said: “It’s like burglars cutting the wires to your home alarm before breaking in. The trick is that the pathogen has evolved the same kind of enzyme activity that plants themselves use to keep their alarm signals under control.
“By attacking these alarm molecules, the pathogen switches them off before the plant can react – it’s as if the microbe has learned the plant’s own language and uses it against it. When we disabled the genes for these enzymes, the microbes became much weaker at infecting plants.”
As climate change fuels more extreme weather and disrupts farming, crops are left more vulnerable to pests and disease. With global demand for food rising, every lost harvest deepens the risk of shortages and higher prices.
By uncovering this hidden microbial strategy, scientists have opened the door to new ways of protecting crops. Blocking the AA7 enzymes could keep plants’ defences switched on, helping farmers safeguard yields in an increasingly uncertain climate.
