Using accelerated genetics to improve food: biological and social realities
Professor Caitilyn Allen UW-Madison Dep’t of Plant Pathology
FRI-IFSH Food waste and sustainability: strategies to improve food safety, food security, and nutrition Overview • What are Accelerated Genetics? • How Are GM Foods Produced? • What are the Biological Risks of GM Foods? • Disconnect Between Real & Perceived Risks of GM Foods • How GM Foods Improve Sustainability & Reduce Waste • What’s Next? Undetectable gene editing with CRISPR What are Accelerated Genetics?
Genetically Modified Organisms…. GMOs What are Accelerated Genetics?
Genetically Modified Organisms….
Frankenfood! How Are GM Foods Produced?
The hardest part: identify a trait to modify
• Higher yield? • Stress tolerance? • Improved nutritional quality? • Better processing traits? • Longer shelf life? Find gene(s) encoding the trait & move them into a crop Using a gene gun to move DNA encoding the desired trait into plant cells Each cell can give rise to a whole new plant
A plant can be regenerated from one transformed cell
Every cell in the plant contains the new DNA
This plant is a GMO, or transgenic plant Transgenic crops contain one or a few genes of known function
Big Positives:
• Technical process is very fast • Results are highly predictable
Big Negatives:
• Regulatory process is costly & slow (can exclude nonprofits) • Social acceptance: consumers are suspicious of GMOs • Social acceptance: consumers are suspicious of GM foods If GM foods are controversial, why not just improve crops with traditional breeding? Traditional breeding has already changed many crop plants dramatically Traditional breeding has already changed many crop plants dramatically Traditional breeding has already changed many crop plants dramatically – not always for the better - Breeding for color and shelf-life has reduced flavor (tomatoes, apples) - Breeding for shipping tolerance has reduced nutrition (iron in spinach becomes nutritionally unavailable with increased oxalic acid) If GM foods are controversial, why not just improve crops with traditional breeding?
• Traditional breeding is very slow (years to generations)
• Involves combining whole genomes of two parent plants
• Often introduces undesirable or unknown traits Breeding using wild relatives can introduce: • Disease resistance • Insect resistance • Better color, flavor • Hardiness (to cold, drought...) • Many other traits Wild relatives can also introduce toxins or allergens • Ex: Wild potato relatives contain toxic alkaloids • Need years of backcrosses to remove these traits • Impossible if species are not closely related
http://hila.webcentre.ca/research/teosinte/teosinte_hopi_blue.jpg Transgenic technology can change traits very precisely:
• Adding 2 bacterial genes to increase Vitamin A in Golden Rice • Deleting 1 apple gene to make fruits that don’t bruise or brown History of GM Products in the US: 1982 FDA approves Humulin, human insulin synthesized by genetically engineered bacteria
1992 USDA approves Flavr Savr long shelf-life GM tomato
1995 EPA approves GM corn that makes BT organic insecticide
1996 Herbicide-tolerant “Round Up-Ready” crops introduced
2017 ~75% of the food in an average grocery store contains GMOs Adoption of GM Crops in the US 1996-2018
USDA-ARS Economic Research Service (2018) Recent Trends in GE Crops What are the Biological Risks of GM Foods? What are the Biological Risks of GM Foods?
We have longitudinal population-wide data:
Number of adverse effects, illnesses, or deaths associated with the widespread human or animal consumption of GM food over the past 22 years: What are the Biological Risks of GM Foods?
We have longitudinal population-wide data:
Number of adverse effects, illnesses, or deaths associated with the widespread human and animal consumption of GM food over the past 22 years: - 0 - Independent scientific analyses agree that current GMO crops are safe to eat:
• UN World Health Organization (WHO) • U.S. National Academy of Sciences • American Medical Association (AMA) • American Association for the Advancement of Science (AAAS) • The European Union • French Académie des Sciences • American Society for Cell Biology • Union of German Academies of Sciences and Humanities • Genetic Literacy Project (Non-profit, non-partisan) • And many others…. Disconnect Between Real & Perceived Risks of GM Foods • Food is personal; food & farming have great cultural significance • Fear or suspicion of eugenics, and of large corporations (Monsanto Effect) • Suspicion of new or unfamiliar technologies; the unfamiliar seems riskier than the familiar • Confirmation bias: I trust organic foods, so I distrust GM crops July 2016 US Congress passes watered-down law requiring labeling of GM foods
With words: July 2016 US Congress passes watered-down law requiring labeling of GM foods
With QR Code: Anti-GM food groups object: The counter-label: What do you think, Prof. Allen? Transgenic crop production is not inherently dangerous In many ways, it’s just a faster and much more precise version of traditional crop breeding Like most technologies, it can be applied in dangerous or dumb ways Case-by-case regulation is needed Anti-GM Food Attitudes Have Global Effects Case Study #1 Bananas:
World’s 4th most important food crop
Less than 10% are grown for export; 90% are locally consumed Sub-Saharan Africa grows 1/3 of the world’s bananas
Bananas supply 30- 60% of daily calories in Uganda, Rwanda & Burundi
Bananas are also a major source of cash income 2001: a new banana disease appeared in Africa: Banana Xanthomonas Wilt, or BXW Impact of BXW
53% production loss
~$8 billion over past 10 years
Cooking banana prices up by 40% in Uganda A dying banana plantation is a family catastrophe:
• Food insecurity • Internal migration • Kids leave school An NGO, the IITA, made a BXW-resistant transgenic banana by adding two genes from sweet pepper
These plants were fully resistant to BXW in the field
(Tripathi 2014 Nature Biotechnology) 10 years after the first field tests, Ugandan farmers are still waiting for approval of disease- resistant transgenic banana plants
GM (left) & control (right) bananas Tripathi 2014 Nature Biotechnology “If people are going to die of hunger today, then we cannot be talking about the future. If GM is going to provide a solution, then as Africans we need to embrace it.” -Arthur Kamenya, Ugandan banana farmer Case Study #2: Papaya Trees resistant to Ringspot Virus (PRSV) Case Study #2: Papaya Trees resistant to Ringspot Virus (PRSV)
- the worst papaya disease - transmitted by aphid insects PRSV appeared in Hawaii in 1992
Papaya yields fell 45% over the next 6 years 1998: Release of the genetically modified “Rainbow” papaya cultivar
- immune to PRSV because it silences the virus coat protein gene Traditional vs. GM papaya Papaya trees exposed to PRSV parent transgenic Hawaiian papaya yields recovering after introduction of PRSV- resistant GM “Rainbow” trees - 71% of Hawaiian papayas are now GM
- Significantly decreased pesticide use
- Consumers accept GM Papaya What’s Next? - Gene editing with CRISPR New technology changes just a few bits of DNA code: extremely precise
April 2018- USDA: “Crops created with gene editing are indistinguishable from products of crop breeding”
July 2018- EU court rules CRISPR plants must be regulated like conventional transgenic crops
Major problem for regulators: CRISPR is undetectable The first major CRISPR crop? Chocolate production employs 50 million people worldwide, generates >$100 billion But… • 20-30% of all cacao pods are lost to disease • Climate change will reduce cacao yields
M&M-Mars and U. California-Berkeley are using CRISPR to increase disease resistance & heat & drought tolerance of cacao trees Will consumers accept this chocolate? Thanks for your attention!