Developing disease-resistant crops using SRG1

Researchers from the University of Edinburgh have discovered the gene that helps plants to control their response to disease. The team suggested that their work could help efforts to enable the growth of crops that are resistant to infection.

Scientists studied how plants produce tiny amounts of nitric oxide when they are under attack from bacteria or viruses. The gas produced then accumulates inside the plant cells, and trigger a response from the immune system of the plant.

The common cress plant, Arabidopsis thaliana, was used to study the gene that were triggered as nitric oxide levels increased. The team identified the previously unknown SRG1 gene to be rapidly activated by increasing levels of nitric oxide. The gene is also triggered during periods of 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 the activity of the SRG1 gene, the team was able to demonstrate 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 findings could lead to ways to fine-tune the gene’s activity to boost disease resistance, pointing towards more resilient crop breeds or new treatments for infections.

It could help curb crop losses incurred by plant diseases. These are the leading cause of crop losses worldwide, accounting for 10 per cent of lost produce in key varieties.

An overactive immune system damages plants and stunts their growth, in the same way that auto-immune diseases in people cause the immune system to attack the body. Researchers say that similar mechanisms, are likely to be found in many other species, and their findings could enable insights into fundamental processes that underlie immune regulation.