What Did COVID Teach Us About Preparing for a Plant Pandemic?
As the world continues to fight COVID-19, the menace of infectious disease has never been more apparent. The next devastating pandemic could strike plants. Agricultural pathogens are evolving and spreading at a troubling rate — and the COVID pandemic offers important lessons for how we should prepare for them.
Plant diseases can be catastrophic. One of the worst was Panama disease, which destroyed banana plantations in Central and South America in the 1950s, devastating a critical food source and industry. Panama Disease is caused by a fungus, and, like most fungi, it spreads through spores. Those microscopic particles are carried by the wind, rain and soil — in this case, all the way from Panama throughout Central America and into South America.
Spores spread easily by their nature, but global trade and climate change are accelerating this process. Powerful storms and other extreme weather events bring pathogens to new regions where plants have not developed resistance. Modern monoculture farming only increases crops’ vulnerability to infection.
Effective solutions exist to control plant diseases: chemical fungicides, resistant crop varieties and the emerging use of biological pesticides. The company where I work, Joyn Bio, is in the business of biologicals, where we engineer naturally occurring microbes to create high performance biopesticides and biofertility products.
However, just like SARS-CoV-2, plant diseases mutate quickly, and variants require new control strategies. For example, Panama disease was initially defeated by the introduction of the now-familiar Cavendish banana variety, which was resistant. However, through mutation, a variant of the disease can now infect these plants and threatens commercial banana production globally.
To protect plants against breakthrough pathogens, we need to prepare. The past years have unfortunately shown us the importance of such preparation.
While it’s not yet possible to vaccinate plants like we vaccinate humans, we can learn from the success of COVID-19 vaccine development, which happened in record time by building upon a solid scientific foundation. Moderna produced its vaccine prototype days after accessing the viral genome sequence — an achievement that was possible only because of existing research in immunology and virology, coupled with new technologies for vaccine development, like mRNA vaccines.
In agriculture, we have effective surveillance systems to warn us of emerging agricultural pathogens, but we lack the framework to rapidly develop solutions to those threats. We need to build the technical framework now, because once in the throes of a pandemic, it will be too late.
A new framework could draw on programs to accelerate the development of human antibiotics; because of the evolution of antibiotic resistance in bacteria, novel treatments are necessary, and our best bet is to identify threatening “superbugs,” then prototype new antibiotics before those strains break out.
In the agricultural world, mega-threats are mostly fungi, which are responsible for the majority of plant diseases. Existing fungicides and plant-breeding techniques are effective and widely used, but in the event of a breakthrough, we’re in trouble. It may require a decade or more to develop new chemical agents or plant-breeding solutions.
In the interim, there are opportunities to build upon progress in synthetic biology to advance biofungicides. At Joyn Bio we are working on new fungicidal modes of action and microbes to deliver these to crop plants. Biofungicides encompass a broad category of solutions ranging from live microbes to biological chemistries like proteins and nucleic acids. We can “preload” the discovery and development of new treatments in this category using proven biotech tools.
Genetic engineering technologies and synthetic biology tools allow us to identify safe and effective biofungicides, supercharge their performance and rapidly scale up their production.
A rapid-response strategy is possible using this model, but will require a few key elements:
- Pretesting for safety and efficacy: We can speed the transition from laboratory to field by focusing on general categories that are known or likely to have very low safety risks for humans and the environment. One approach is to deliver biofungicides to crops via pretested hosts (such as harmless bacteria). Another is to use proteins or RNA that only target a specific fungal species and then rapidly degrade in the environment. Of course, another big learning from COVID-19 is the importance of education and communication to enable the societal acceptance of new technologies.
- Establish libraries for rapid screening and optimization: Genetic libraries have been fundamental to synthetic biology innovation because they permit the rapid construction and evaluation of diverse populations of genetic variants. The same framework applies to biofungicides; we can screen thousands to millions of variants to identify and optimize those that selectively interfere with a given pathogen. Once we know that a specific agent can disrupt a disease, we can develop the means to deliver the solution, whether it’s through an engineered microbe (as we are doing at Joyn Bio) or biomolecules like RNA (pursued by GreenLight Biosciences) and proteins ( such as Biotalys’ antibody technology).
- Scalable production using standardizing manufacturing and delivery systems: Biotechnology offers the opportunity to rapidly prototype and scale the production of biofungicides using standard manufacturing systems. Thanks to inexpensive, large-scale production and shelf-stable formulations, we can rapidly transition laboratory solutions out to the field for evaluation and application.
The question is not whether we’ll experience a plant pandemic but whether we’ll be ready when it strikes. To protect crops and food supplies, we need to develop a preloaded solution — a platform that can be rapidly scaled and deployed in an emergency.
While we can not protect every plant from every pathogen, we can anticipate a subset of likely diseases on keystone crops and take steps to prepare solutions. We can build our lifeboat today or wait and see what happens when the crisis comes. The technologies and capabilities exist today. The choice of whether or not we deploy them is ours.