A GENE that helps plants control their response to disease could aid efforts to develop crops which are resistant to infection.

Researchers at Edinburgh University think their findings could lead to ways to fine-tune the gene’s activity to boost disease resistance, and could open the door to more resilient crop breeds or new treatments for infections.

They could also help curb crop losses incurred by plant diseases – the leading cause of crop losses worldwide.

The team studied how, when plants are being attacked by bacteria or viruses, they produce tiny amounts of a gas known as nitric oxide. This accumulates in plant cells and triggers a response from the plant’s immune system. They used a common cress plant to study the genes that were triggered as nitric oxide levels rose, and found a previously unknown gene – SRG1 – was rapidly activated by nitric oxide and was also triggered during bacterial infection. Further analysis showed that SRG1 unleashes the plant’s defence mechanism by limiting the activity of genes that suppress the immune response.

By altering its activity, the team demonstrated that plants with higher levels of defence proteins produced by the gene were more resistant to infection.

They also found that nitric oxide regulates the immune response, ensuring the plant’s defence system does not over-react.

The study, published in Nature Communications, was funded by the BBSRC and the National Natural Science Foundation of China. Professor Gary Loake, of the School of Biological Sciences, who led the study, said: “Our findings provide a missing link between mechanisms that activate and suppress the plant’s response to disease. We were surprised to see this might be common to humans too.”