New Study Shows How Plants Fight off Disease

Hypothetical structural model of the assembly of TIR domains during signalling, from the SNC1 immunity receptor found in Arapidopsis plants. Individual subunits are shown in different colours, with β-strands shown as arrows and α-helices shown as cylinders. Image: Bostjan Kobe.

A University of Queensland-led study has highlighted the minute details of how the plant’s immune system leads to its ability to resist disease.

UQ School of Chemistry and Molecular Biosciencesand Australian Infectious Diseases Research Centreresearcher Professor Bostjan Kobe said the finding was significant as food security was an increasingly relevant problem worldwide.

“It is estimated that pre-harvest plant diseases account for up to 15 per cent of crop losses per year,” he said.

“Breeding resistant plant varieties has been the main strategy to combat plant disease, especially because pesticides can be detrimental to the environment.

“While many plant resistance genes have been identified in the past 20 years, we have a limited understanding of how the products of these genes work.

“In the report, we described how one part of the immune receptor protein signals to make the plant resistant to disease.”

The research team used x-ray crystallography to understand how the immune receptors assembled during signalling.

Plant molecular biology experts from Australia, South Korea and USA, demonstrated that these interactions were crucial for converting the signals that ultimately made plants resistant to disease.

“It is vitally important that we understand how plant immune systems function,” Professor Kobe said.

“Crop losses present a significant economic, environmental and social challenge in a world facing increased demands on food, fibre and biofuels.

“In the long-term, this research will help make more effective synthetic resistance genes that can be used to provide additional protection in Australia and worldwide from crop diseases.”