The ability of bacteria to transmit diseases throughout the Plant Kingdom might be more prevalent than previously thought, based on recent research findings.
The ability of bacteria to transmit diseases throughout the Plant Kingdom might be more prevalent than previously thought, based on recent research findings.
Researchers from the John Innes Centre employed a comparative evolutionary method, looking at the variety of Pseudomonas syringae bacteria, to explore how this pathogen infects plants that are not closely related.
In their experiments, led by Dr. Phil Carella, the team examined the toxin syringomycin produced by the most commonly infectious strains of P. syringae, and assessed its impact on both non-flowering and flowering plants.
The findings revealed that syringomycin was harmful to non-flowering plants (which included model species such as liverworts and ferns), leading to tissue death and the activation of stress-related genes.
Interestingly, these effects were more pronounced in non-flowering plants compared to flowering ones. This was unexpected, given that much of our existing knowledge about how disease-causing bacteria interact with plants is focused on flowering species, which comprise many of our key crops.
By incorporating non-flowering plants into their study, published in Cell Host and Microbe, the researchers contribute to a growing array of evidence demonstrating that bacterial pathogens have the ability to infect a wide range of unrelated plant species.
“Each plant species used in our research has followed a distinct evolutionary path since they last shared a common ancestor 500 million years ago. Nevertheless, a single group of pathogens can infect all of them, utilizing a common set of virulence factors,” Dr. Carella explained.
“Our findings suggest that pathogen virulence may be more universal among plants than previously realized,” he noted.
The researchers propose that P. syringae virulence is likely rooted in fundamental processes that are shared across the Plant Kingdom. Particularly, syringomycin appears to disrupt cell membranes in each of the various plant species studied.
Although non-flowering plants tend to be viewed as less advanced than their flowering counterparts, which evolved later, this research underscores the significance of studying the entire spectrum of plant life to uncover essential mechanisms and processes that could be leveraged to protect food crops from diseases.
“In summary, our research indicates that diverse plant species can provide valuable insights into plant-pathogen interactions that are applicable to crop disease research. While we may not consume liverworts, they offer important lessons about the key virulence mechanisms of significant pathogens,” Dr. Carella commented.
The next phase of this study will investigate how the toxin contributes to the bacterial spread, as well as its interaction with bacterial effector proteins in facilitating disease.
Another intriguing avenue for future research is to understand why certain populations of P. syringae do not possess the toxin.
The team also plans to broaden the variety of plants in their experiments to identify those that exhibit resistance to bacterial pathogens.
A study titled “A necrotizing toxin enables Pseudomonas syringae infection across evolutionarily divergent plants” appears in Cell Host and Microbe.
