Engineering resistance with help from Liverworts, Mosses and Ferns
Plant diversity and synthetic biology offer solutions to the global challenge of crop protection
Non-flowering plants such as liverworts, mosses, and ferns belong to divergent lineages with ancient origins dating back to hundreds of millions of years, unlike the more recently evolved flowering plants. These non-flowering plants consist of over 78,000 species that are often overlooked by the scientific community. Consequently, the molecular mechanisms underpinning a multitude of biological processes are often thought of as simple prototypes of seemingly complicated programs in flowering plants – which include major crop plants. This view is mistaken. Research at the John Innes Centre and collaborators at The Sainsbury Laboratory, highlighted the complexity of the immune system of non-flowering plants and the commonalities and differences with flowering plant immunity.
Pathogen recognition is largely mediated by nucleotide binding and leucine rich‐repeat (NLR) immune receptors, which raise the alarm whenever a plant is infected. Upon pathogen perception, these immune receptors trigger an immune reaction within plants. This response is effective at stopping pathogens and parasites in their tracks and preventing disease.
Over hundreds of millions of years, plants have evolved a diverse repertoire of these immune receptors to detect pathogens. The immune receptors of flowering plants is a well-studied subject, but much less is known about the form and function of these immune receptors in divergent lineages of the non-flowering plants.
Our Research
Collaborative research carried out by the John Innes Centre, The Sainsbury Laboratory and others discovered that non-flowering plants, and mosses in particular, contain an expanded set of immune receptors. Using a combination of genetic and computational tools, researchers have found remarkable structural and functional similarity between immune receptor domains across diverse plant lineages, even though the genetic sequences of these domains are highly variable.
Engineering novel resistance in crops
The deployment of resistance genes in agriculture is often short-lived as pathogens tend to rapidly evolve to evade plant defence. Liverworts, mosses, and ferns may offer exciting new solutions in the global challenge of protecting crops from the threat of disease. Biotechnological techniques have revealed that immune receptor domains which protect plants against pathogens are transferable between flowering and non-flowering plants. This discovery is a breakthrough in understanding and offers practical applications for crop protection, opening new possibilities for bioengineering immunity in major crop plants.
Researchers at The Sainsbury Laboratory are attempting to bioengineer “made-to-order” immune receptors for durable and versatile disease resistance. NELARIX, a biotech venture spinning out from The Sainsbury Laboratory is offering exactly this. Harnessing their patented bioengineering technology enables researchers to deliver “new-to nature” solutions for resistance to plant disease.
Future Impact
Researchers are now taking a comparative evolutionary approach to determine how particular pathogens infect distantly related plants. Experiments have shown the capacity of bacteria to spread disease across the Plant Kingdom may be much more widespread than previously suspected. A collaboration between the John Innes Centre and the University of Illinois has revealed how Pseudomonas syringae, a bacterial plant pathogen, infects evolutionarily divergent plants. Investigating Pseudomonas infection in liverworts, ferns and flowering plants revealed a fundamental mechanism for virulence that is shared among the Plant Kingdom. This research emphasises the importance of analysing diverse plant species to understand fundamental biological mechanisms which could be applied to defending crop plants against disease. Future studies across divergent systems may reveal other conserved vulnerabilities that microbes exploit to cause disease. Harnessing the diversity of plant immune receptors and fine-tuning these through further synthetic biological enhancements will together tackle the broadly virulent pathogens impacting our crops.
