A study by researchers from the John Innes Centre isolated soil bacteria in a potato field finding how it protects potatoes from scab, a Jan. 18 news release says.
Hundreds of strains of Pseudomonas bacteria in soil were isolated and tested, with the genomes of 69 strains being sequenced. The genomes were compared to show which suppressed pathogen activity, the release says. The team was then able to identify a key mechanism in some strains which protects potatoes from disease-causing bacteria.
By using a combination of chemistry, genetics and plant infection experiments the team showed the production of small molecules called cyclic lipopeptides are important to the control of potato scab. The small molecules have an antibacterial effect on the pathogenic bacteria which cause common scab, and they help the protective Pseudomonas move around and colonize the plant roots.
The release notes the experiments also showed irrigation causes substantial changes to the genetically diverse Pseudomonas population in the soil.
“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,” Alba Pacheco-Moreno, first author of the study, says in the release.
By exploiting advances in high-speed genetic sequencing, the method can screen the soil microbiome for therapeutic bacteria and work out which molecules are being produced to suppress pathogenic bacteria, the release notes. It can also show how these beneficial bugs are affected by agronomic factors such as soil type and irrigation.
The study was published in eLife.