Smart soil bugs can offer farmers eco-friendly disease control

Scientists have developed an innovative way to control a range of damaging crop diseases using native, beneficial soil bacteria.

Researchers behind the agri-tech innovation say they hope to give farmers an eco-friendly way to control bacterial diseases such as potato scab, which can have a devastating effect on crop yields and quality.

The John Innes Centre team isolated and tested hundreds of strains of Pseudomonas bacteria from the soil of a commercial potato field. The genomes of 69 bacteria strains were then sequenced.

The team then compared the genomes of those strains shown to suppress pathogen activity with those that did not. This enabled them to identify the mechanism that protects potato crops from harmful disease-causing bacteria.

The production of small molecules called cyclic lipopeptides has an antibacterial effect on the pathogenic bacteria that cause potato scab. This helps the protective Pseudomonas move around and colonise the plant roots.

Substantial changes

Experiments using a combination of chemistry, genetics and plant infection also showed that irrigation causes substantial changes to the genetically diverse Pseudomonas population in the soil.

Study lead author Alba Pacheco-Moreno said: “We hope that our study will accelerate the development of biological control agents to reduce the application of chemical treatments which are ecologically damaging.

“The approach we describe should be applicable to a wide range of plant diseases because it is based on understanding the mechanisms of action that are important for biological control agents.”