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

With words:

July 2016

US Congress passes watered-down law requiring labeling of GM foods

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 fullyresistant to BXW in the field

(Tripathi 2014 Nature Biotechnology)

GM (left) & control (right) bananas

Tripathi 2014 Nature Biotechnology

10 years after the first field tests, Ugandan farmers are still waiting for approval of disease-resistant transgenic banana plants

“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 PRSVparent 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 CRISPRNew 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!

callen@wisc.edu