GMO Technology is Simply Precision Breeding

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Eleven years ago when I began my career as

a professor at the University of Florida, I would

enjoy the sunny drives downstate from

Gainesville. As Id progress further south, the

landscape became dominated by a truly

beautiful sightlush orange groves bearing

Floridas iconic fruit. The sea of dark green

foliage contrasted the cloudless blue sky, and

was punctuated with frequent spots of bright

orange. Its scale was amazing, a credit to the

farmers that grew them and the plant breeders

that coalesced favorable genetics into elite

productive trees bearing succulent fruit. It was a

combination of plant genetics, orchard

management and a magical environment that

produced this wonderful sight.

Today, the same drive is remarkably different.

Many of the groves that stood as a jungle of

leaves and frequent fruits now stand as gray

skeletal botanical remains. Bare branches

extend coldly above untended weeds below,

choking out whats left of occasional patches of

yellowing leaves and an occasional small green

fruit. Devastation is hardly complete. Other

groves have remained productive, but only

through intensive management and high cost.

Even in these cases the leaves are noticeably

yellow and the oranges fall easily from the trees

to the ground below, unusable.

The Florida citrus industry knows this decline

as the disease huanlongbing, also known as

citrus greening. The disease is a complex web ofsymptoms caused by a bacterial colonization of

the plants vital vascular tissues, blocking

nutrient flow, reducing root mass and choking

out nutrition to tissues that need it. Infected

trees may stand for years before developing

symptoms. They also may unknowingly spread

the pathogen. The disease travels from tree to

tree, vectored by an insect called the Asian

citrus psyllid, a small creature with penetrating

mouth parts that become contaminated with the

bacteria before passing it to the next tree. As of

the writing of this article, it is estimated that

70 percent of Floridas trees are infected. The

disease has also been identified in California,

Texas and Brazil, as well as many other places in

the world. Because of its long-latent period, a

minor patch of infection is a cold harbinger of a

much larger problem to come.

To combat the problem plant breeders have

sprung to action. There is a worldwide search for

resistant trees, trees containing a gene that may

make the tree unattractive to the psyllid, genes

that could block the bacterium, or perhaps

genes that allow the tree to live just fine while

infected. If found, such a gene could be bred

into elite orange varieties, conferring resistance

and slowing, if not ending, the disease. But even

if that gene was identified today, it would take

years to breed it into existing plants, as each

generation of trees only flowers after years in the

field. Obtaining the correct combination of good

genes against the greening disease and keeping

the good genes that support fruit productivity

might take decades. A vital industry that

produces a healthy and delicious product cannot

wait that long.

Solutions Exist

Disease-resistance genes are well understood

in plants and hundreds of them have been

characterized. We eat thousands of them and

their products in every salad. These genes encode

proteins that oppose microbial growth through a

wide variety of mechanisms. What if one of theseresistance genes could be moved from something

like an apple tree, spinach plant or maybe a small

weed to citrusand then arrest citrus-greening

disease? Such transfers across diverse species by

traditional breeding are just not possible, as it is

as difficult to cross a grapefruit tree with a banana

as it is to cross a mouse with an elephant.

But what if that one effective disease-

resistance gene, naturally occurring in a food

plant we already eat, could be placed into the

citrus tree, making it immune, or at least

tolerant, to the disease? It could be done, it has

Disease-resistance genes

are well understood in

plants and hundreds

of them have been

characterized. We eat

thousands of them and

their products in every

salad. These genes

encode proteins that

oppose microbial growth

through a wide variety

of mechanisms. What if

one of these resistance

genes could be movedfrom something like an

apple tree, spinach plant

or maybe a small weed to

citrusand then arrest

citrus-greening disease?

GMO Technology is Simply

Precision BreedingBY KEVIN M. FOLTA

In need of a solution

5/26/2018 GMO Technology is Simply Precision Breeding

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been done, and the plants seem to thus fardo well in greenhouse trials hot with the

disease. Here the gene that helps the plant

survive the disease was simply plucked from

one plant (in this case a gene from spinach)

and moved to citrus using a process that has

been with us for decadesrecombinant DNA

technology. Many other recombinant DNA, or

transgenic (commonly referred to as

genetically modified organism [GMO])

solutions, are in the works and show promise.

While not commercially available, the

example from oranges shows how thetransfer of a gene from one species to

another can work to potentially solve a

monumental problem. Moving a gene is what

plant breeders have done for thousands of

years, shuffling the genetic deck with

human-mediated hybridizations to try to place

a stack of favorable genes into one single

genetic background. Every fruit or vegetable

you eat today has been genetically remodeled

by plant breeders, crossing plants that would

typically never hybridize without human

intervention and significant cost. The geneticmixes have been guided by careful hunches,

observations and maybe some genetic

knowhow, but in general the process has a

major element of randomness and is fraught

with unknowns. Breeders know they moved

the gene of interest if they can follow the trait

it confers, but theres no easy way to account

for the other negative genetic baggage that

travels along, or the good genes that may be

lost. Some plant breeders have used

chemicals and radiation to damage DNA andinduce genetic changes. These practices, and

many others that are surprisingly random,

dramatic and unnatural, are the foundation of

many foods we eat, and have never been

questioned for safety. It simply is another way

to generate genetic variation, the basis of a

new valuable trait.

But what if a researcher were to move that

one understood gene, rather than a genome

full of thousands of unknowns? What if a

gene could be moved to an elite variety

without losing favorable traits, just gaining theone desired trait? This is the process of

creating a transgenic plant, also thought of as

a GMO. The GMO is indeed a misnomer, as

GMO crops undergo almost no genetic

modification relative to the massive

restructurings that come with conventional

breeding. Making a transgenic plant moves a

single understood gene into a new plant,

bringing with it the trait of interest. For

example, in citrus this might be a gene that

makes the plant immune or asympomatic to

the greening disease.Recent examples show how the technology

can lead to healthier products. In rice, such

engineering has been used to introduce a

pair of genes that allows rice to produce

beta-carotene, the orange-yellow pigments in

carrots. Upon consumption, the beta-carotene

is converted to vitamin A, and could possibly

alleviate disease and blindness caused by

vitamin A deficiency. This solution remains in

development, now moving into productive rice

cultivars prior to deployment. The rice will bedonated, royalty-free, to small farmers.

Another possibility is using a potatos own

gene sequence to shut off genes associated

with the production of asparagine (an amino

acid) in the potato tuber. Potatoes produce a

small yet significant amount of acrylamide

when cooked at high temperatures, based on

natural chemical reactions with asparagine.

Acrylamide is toxic, so decreasing asparagine

in the potato tuber could make a more

healthful potato.

These two examples are not science fiction.They are all plants that have been designed to

produce desirable products containing an

important trait. Many more are being developed

and will bring benefits to consumers, farmers,

the needy or the environment.

These benefits have been realized already.

In 17 years of cultivation, GMO crops have

ensured farmer yields and brought great

environmental benefits. There is no question

that farmers appreciate these seeds for the

traits they bring, making it profitable to

produce agronomic crops like corn, canola,soybeans and cotton. Some of these crops

are grown with a trait that allows fields to be

treated with mild herbicides (namely

glyphosate, a compound with the acute

toxicity of table salt, replacing less safe

herbicides) to combat competing weeds.

Others have a gene that leads to the

production of a protein that is toxic only to

larvae of specific insects, stopping crop

damage without insecticidal sprays. These

Source: Joe Raedle/Getty Images; Originally published in the Washington Post online Jan. 12, 2014

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genes and their products have been studied

for decades and are among the most

well-understood genes and gene products in

plant biology. However, these plant lines have

mostly benefited the farmer and the

environment, as farmers achieve desired

yields with fewer inputs (less fuel, labor,

chemicals), less soil disturbance and certainlyless broad-spectrum insecticide. The

technology works. Thats why farmers use it.

Ninety-some percent of corn, soy, cotton and

canola acreage is GMO.

Of course, every technology has limitations.

The widespread use of herbicide-resistant

crops has opened opportunities for resistant

weeds to thrive in fields, as their competitors

are killed off by herbicide. This selection for

surviving weeds has led to widespread

invasion of resistant-weed species that will

need new technologies to again suppress.Solutions are being developed to slow this

evolutionary arms race.

In any situation there are benefits and

risks, and the emergence of resistant weeds

is certainly a limitation of the technology. Yet

in 17 years of intensive cultivation, these

crops have delivered far more benefitsthey

allow farmers to remain profitable, keep food

costs low, and provide renewable sources of

fuels and fibers. Products from these crops

appear in 70 percent of grocery store foods,

and since their deployment almost twodecades ago, there has not been one single

case of illness, allergy or death that could be

attributed to these plant products. Before

marketing they must pass a rigorous safety

battery, making them safer than products

produced by conventional breeding.

Manufacturing Risk,

Manufacturing Fear

History shows whenever a revolutionary

scientific concept or new technology is

adopted, there always is some skepticism.Thats healthy, to a point. From the earth in

the center of the universe, to explorers sailing

off the edge of the earth, to coffee,

pasteurization, immunization and in vitro

fertilizationjust about every major scientific

advance has garnered a collection of

detractors and their dissent. Those in

opposition try to argue against carefully

assembled scientific evidence with opinions

founded only on closely held beliefs. However,

science tends to find and reinforce hard

truths rather quickly. In all of these cases

(and hundreds others) beliefs inconsistent

with facts have a hard time competing with

hard science. So how to do you influence

hearts and minds if you dont have evidence

on your side? You manufacture risk around

the technology in question. For some,

manufacturing perceived risk has become afull-time job, and a profitable one.

Animals in general dont like risk. Risk

avoidance is a deeply ingrained program that

has ensured the forward movement of genes,

as, in general, cautious tendencies made it

more likely for our ancestors to survive, get

interested in a mate and eventually

reproduce. To this day, humans maintain a

strong aversion to risk and those opposed to

GMO technology exploit this inherent

tendency. Scaring people with food-based

technology is an easy charge. Food has deepcultural meanings: We have plenty of it. We

have plenty of choices. Then, the topic is

complex; we have little reverence for science

education, and the concepts sound

somewhere between sterile and alien.

Together it is a perfect storm to manipulate

fear and increase the perception of risk to

achieve a political or profitable agenda.

This is the state of the discussion of

agricultural biotechnology. The technology is

not new; it has been in development for more

than 30 years and has been successfullydeployed for the better part of two decades.

The crops grown are among the best tested

in the world, and the genes and traits are

understood with remarkable resolution. The

technology has been rapidly adopted by

farmers, and undoubtedly had profound

impacts in saving time, labor, fuels and

environmental impacts (such as decreased

insecticide use). Again, problems like

herbicide-resistant weeds cant be ignored,

but the risk and benefit equation is heavily

weighted to the benefits.There is no question that these

technologies have been safe and effective.

There is massive potential in how they may

help the farmer, the consumer, the needy and

the environment going forward. The central

barrier is the anti-scientific beliefs and

influence of activists that manufacture fear to

influence public perceptions.

Who do we want dictating public policy

around the science of food safety, food

security and food technology? Right now it is

a rabid activist fringe ranting unabated by

scientific opposition. The tide is changing. As

science is distorted in the name of political

agendas and profits, a traditionally quiet

cadre of public-sector scientists is waking up

to the reality that those who know nothing are

attempting to dictate a scientific conversation.Farmers also realize a vocal minority is

attempting to dictate the seeds they can grow

and who they can buy them from. Fueled by

an Internet where the achievements and

reputations of scientists are viewed as equal

to rants of self-appointed experts, it is

important to let science, evidence and reason

prevail in affecting public opinion and shaping

public policy.

The citrus industry needs a solution. A tree

takes years to grow and be productive. Agene from another plant may be a solution. It

could save an industry and maintain the

consumers pipeline of healthy juice and fresh

oranges. One of the barriers separating the

problem and a solution is the concern that

consumers will question the product, or even

worse, boycott and bury it in misinformation.

It is sad that public scientists produce a

solution that just might work, but its

development and deployment will be slowed

because of manufactured fear.

Citrus is just one case where a biotech

solution could have great dividends. We live

on a planet where a billion people wake up

with empty bellies, where one missing

nutrient is the difference between life and

death, and where crop plants need to be

more prolific with less environmental impact.

Major industries need fast solutions.

Transgenic technologies simply do what plant

breeding has always donemove a gene

from one background to another. It is

integrating genes in months or years rather

than decades. We need to be using every tool

to solve todays agricultural challenges and

precision breeding through biotechnology will

be part of that solution.

Kevin M. Folta is the associate professor and

chairman of the Horticultural Sciences Department at

University of Florida, Gainesville.

Reproduced with permission from SupplySide Boardroom Journal, March 2014. 2014 Virgo Publishing. All Rights Reserved.For electronic usage only. Not to be printed in any format.