key: cord-0973001-bwd0oi6q
authors: He, Sylvia; Creasey Krainer, Kate M.
title: Pandemics of People & Plants: Which Is the Greater Threat to Food Security?
date: 2020-06-17
journal: Mol Plant
DOI: 10.1016/j.molp.2020.06.007
sha: ece571d8e939fd2061a9cee90a5d7c8255bd1843
doc_id: 973001
cord_uid: bwd0oi6q

nan

Whereas the elderly and obese are at greater risk of fatality from COVID-19, it is children and the malnourished who are at greatest risk from the consequences of plant disease. There is no doubt that SARS-CoV-2 has negatively impacted our food-supply chain, causing shortages and rising costs, yet plant pathogens have a significantly greater impact. Current hunger-related fatalities have reached 4 million this year, 10 times the number of COVID-19 fatalities. Unlike COVID-19, pathogen-related crop loss disproportionately impacts food-insecure populations in developing countries (Savary et al., 2019) . The developed world is spared the worst outcome of crop epidemics, namely famine.

Plant pathogens and pests are responsible for up to 40 percent of maize, potato, rice, soybean and wheat crop-yield losses worldwide (Savary et al., 2019) . Biotic disease caused by bacteria, fungi, nematodes and viruses, costs the global economy 220 billion USD annually (Nicaise, 2014) . Viruses make up almost half of the plant disease-causing pathogens, at an annual global cost of 30 billion USD (Nicaise, 2014) . Rice is cultivated in 100 countries, supporting nearly half the world's population, and is at risk from In response to the COVID-19 pandemic, the U.S. government granted 4.3 billion USD specifically for disease control, prevention, and global health programs. With its high rate of infection and severity of symptoms, it is not surprising that there is increased urgency to overcome and prevent future SARS-CoV-2 infection. COVID-19 symptoms range in severity, from asymptomatic to multiple organ failure and death. Public-health policies, such as monitoring, screening, contact-tracing, and quarantine, help limit the spread of SARS-CoV-2. However, comparable measures are expensive, labor intensive, and time consuming if applied to control the spread of plant pathogens.

Asymptomatic carriers are the leading cause for infection propagation and disease spread, especially for fruit crops such as citrus, papaya, strawberry, and tomato in disease-free regions (Kado, 2016) . Conventional methods, such as biological (natural predator of vector) and chemical (pesticide application), have been utilized for decades, though they do not eradicate the pathogen. Modeling predictions based on environmental conditions, vector proliferation, and viral-genome evolution, could forewarn new disease emergence. Drone surveillance, self-monitoring and reporting could control both human and plant disease. But pandemics occur unexpectedly, and strategies to combat emerging infectious agents rarely prevent outbreaks. To prevent future outbreaks, awareness, preparation, and long-term funding support are required.

However, there are large funding discrepancies between human and crop disease. The 2020 U.S. budget for Human Immunodeficiency Virus (HIV) research, 2.6 billion USD, is 150 million USD more than the entire budget for agricultural research.

Vaccination is economically sound and less labor-intensive than screening and quarantine measures. Though plants do not share with us an adaptive immune system, the expression of weaker related viruses or viral proteins leads to disease resistance.

Innate immunity in plants, as in humans, protects against pathogens. Antiviral Resistance (R) genes prevent systemic spread by eliciting programmed cell death, and RNA silencing prevents viral replication (Soosaar et al., 2005) . Traditional methods of breeding and grafting can confer such pathogen resistance, but in response to the Papaya ringspot virus epidemic, the first virus-resistant papaya was obtained through bioengineered viral-protein expression, successfully demonstrating plant vaccination. (Ferreira et al., 2002) . Since then, successful RNA silencing-based genetic resistance has been demonstrated in bean, papaya, pepper, plum, potato, squash, and tomato, though the application of biotechnology is underutilized (Khalid et al., 2017) . 

Potential Applications of Plant Biotechnology against SARS-CoV-2. Trends in plant science

Virus Coat Protein Transgenic Papaya Provides Practical Control of Papaya ringspot virus in Hawaii

Asymptomatic and Latent Infections. Plant Bacteriology, The American Phytopathological Society pp

Small RNA Based Genetic Engineering for Plant Viral Resistance: Application in Crop Protection

Crop immunity against viruses: outcomes and future challenges

The global burden of pathogens and pests on major food crops

Mechanisms of plant resistance to viruses

Encyclopedia of Plant Viruses and Viroids