Lesson B1–2



BIOTECHNOLOGY

Student Learning Objectives. Instruction in this lesson should result in students achieving the following objectives:

1 Describe biotechnology and genetic engineering.

2 Explain the differences between genetic engineering and traditional plant breeding.

3 Explain the steps in engineering a plant.

4 Explain how desirable genes are located.

5 Explain how selected genes are introduced into a target organism.

6 Explain how genetically engineered crops are tested.

7 Discuss the benefits and risks of biotechnology.

Anticipated Problem: What are biotechnology and genetic engineering?

I. Biotechnology and genetic engineering are often confused. Biotechnology includes genetic engineering but it also involves much more.

A. Biotechnology is simply the use of living organisms to create or improve something.

Today biotechnology is centered on the modification of living organisms as a result of

our new understanding of genes and DNA. It includes techniques such as:

1. Genetic engineering

2. DNA analysis

3. Genetic mapping

4. Gene transfer

5. Plant tissue culture

6. Biofermentation

B. Biotechnology is being used with microbes, plants, and animals to produce beneficial

products and improve species. It is being applied to many agricultural processes including:

1. Bread making

2. Beer brewing

3. Wine, cheese, and yogurt fermentation

4. Silage fermentation

5. Classical plant breeding

C. Genetic engineering is the manipulation of genes. It is also referred to as recombinant

DNA technology. This involves moving genetic information from one organism into a

different organism or replacing it in the original organism in a new combination. These

changed organisms are called transgenic. A transgenic organism is one that has either

new genetic information incorporated into itself or a unique recombination of its original

DNA.

Anticipated Problem: How is genetic engineering different from traditional plant breeding?

II. Genetic engineering (GE) is different from traditional plant breeding (TPB) in many ways:

A. With TPB, crosses can be made only within the same species or closely related species. This limits the genetic material breeders can work with. With GE, there are fewer limits to the genetic material a breeder can work with. Genes can be taken from any living organism including bacteria or animals and inserted into a plant.

B. When plants are crossed using TPB, nearly 100,000 genes are combined from each

plant. This requires breeders to employ the technique of backcrossing, rebreeding back

to one of the original parents, many times to get rid of unwanted genes and restore

desired traits. With GE, a single desired gene can be inserted into a plant.

C. When a cross is made using TPB, the seeds are collected and the new generation of

plants must be germinated and grown before the results of the cross can be verified.

Using GE, modified plants are grown in tissue culture and the change is verified.

D. TPB requires up to 14 generations to produce a new plant. GE will create a new plant in as few as five generations.

Anticipated Problem: What steps are involved in engineering a plant?

III. The creation of a transgenic organism begins with a selected gene from a donor organism and the insertion of that gene into a host organism. Eight major steps are required to complete this process.

A. A donor which contains the gene that codes for the desired trait is identified.

B. DNA is removed from this organism’s cells and cut into fragments.

C. Fragments of DNA are sorted by size using gel electrophoresis and grouped. The fragment containing the desired gene is then isolated.

D. The targeted fragment is joined with new DNA, making it possible to move the desired gene into the host organism.

E. The altered DNA is moved into the host cells.

F. These transformed cells are grown into a complete transgenic organism.

G. This transgenic organism is grown and tested.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 5

H. The transgenic organism is reproduced to assure that the new gene is transferred to the

progeny.

Anticipated Problem: What methods are used to find a specific gene within an organism?

IV. Creating a transgenic organism begins with locating the specific gene that codes for the desired trait. Genes are specific sequences of DNA contained among all of the DNA inside an organism’s nucleus. In most plants and animals, less than ten percent of the DNA code for genes. A scientist will use a variety of mapping techniques to find a specific gene. There are three kinds of gene maps: genetic linkage maps, physical marker maps, and DNA sequence maps.

A. Genetic linkage maps show where on the chromosome a target gene may be. It will provide the general proximity. These linkages are determined by examining the frequency that different traits are inherited together.

B. Physical marker maps identify the distance between a marker and the desired gene along the strand of DNA. Markers are specific molecular characteristics of the DNA molecule which can be observed.

C. DNA sequence maps describe the order of the bases (ATGC) around and including the

target gene on the DNA strand within the chromosome.

Anticipated Problem: How are selected genes introduced into a target organism?

V. Introducing a new gene into a target organism is a complex process in which many obstacles must be overcome.

A. The desired gene must be cut out of the donor organism and combined with other

DNA before it can be inserted into the target organism. This combination is necessary

for the gene to function, replicate, and be inheritable. This recombined DNA is usually

a plasmid, a self-replicating closed loop that comes from a bacterium. Once inside the

host cell, the plasmid can replicate and be passed on to the next generation.

B. The target cell must remain intact after the transfer or it will not function. These cells

must not be ruptured or they will die. The tough cellulose cell wall must be penetrated

and the new DNA gently moved through the cell membrane.

1. Enzymes can be used to digest the cell wall, creating an exposed membrane. Temporary holes are opened in this membrane to allow gene transfer. Plant cells with no

cell wall are called protoplasts and are very susceptible to gene transfer.

2. A microorganism that naturally penetrates plant cells can be used to transfer DNA

into the target cell. This technique leaves the cell wall intact.

C. There are four methods commonly used to transfer genes and create genetically modified organisms: microinjection, electroporation, biolistics, and vectors. A technique

called viral encoding does not create a genetically transformed organism but does result

in an organism that produces a foreign protein.

1. Microinjection: DNA is physically injected into a cell. A small glass needle is moved

through the cell membrane. After the needle has penetrated the membrane, the new

DNAis simply injected into the cytoplasm. Transformed cells are grown into whole

plants that exhibit the desired trait, reproduced so the offspring contains the new

gene.

2. Electroporation: Placing a protoplast into an electrically charged environment can

cause the cell membrane to become permeable to DNA. The technique of

electroporation uses an electric charge to open holes in the cell membrane, allowing

foreign DNA to enter the cell. The transformed cells are grown and propagated,

with the subsequent generations exhibiting the new trait.

3. Biolistics: In this process, DNA is shot into a cell attached to microscopic metal particles. These particles are fired from a specially modified .22 caliber gun. The particles

move so fast that they can penetrate the cell membrane without doing permanent

damage to it. Cells that survive this process are transformed and can be grown

and propagated.

4. Vectors: A living organism, such as a virus or bacterium, or a plasmid which carries

new genetic information into a target cell is a vector. The desirable gene is spliced

into the DNA of the vector. The vector than penetrates the target cell as part of its

natural life cycle and transforms the target cell through this infection.

5. Viral encoding: In this process, a virus is used to carry a new gene into a cell. This

gene does not become part of the cell’s genetic make up and so is not transferred to

future generations. While the cell is alive and infected with this virus, it will produce

the protein the new gene codes for. This technique is useful in culturing single cell

organisms to produce things such as insulin, antibiotics, and many vaccines.

D. Many techniques have been developed to identify genetically transformed plants. These include the use of reporter genes or marker genes, DNA probes, and immunoassays. These methods can be used to identify a genetically modified plant at any stage of development, from seed to mature plant.

1. Reporter genes: These genes are also referred to as markers or marker genes.

Reporter genes code for an observable trait and are attached to the desired gene

before transfer into the target organism. If the reporter gene is functioning, then the

desired gene will also function. These markers are selected for traits that can be verified

early in the plant’s development.

2. DNA probes: This is a short piece of single-stranded DNA with the complimentary

code for the desired gene. It is labeled with radioactivity. If the gene is present, the

probe will stick and the radioactivity will be detected in the transformed cell. If the

gene is not present, the probe will not stick so there will be no radioactivity detected.

3. Immunoassays: These are capable of detecting the presence of the actual desired

gene without the use of markers or radioactivity. They accomplish this by identifying

the gene product, or protein, that the desired gene produces. Immunoassays utilize

techniques working with animal immune systems involving antigens and antibodies.

An animal is injected with the target protein. This is registered as an antigen

by the animal’s immune system. The animal produces an antibody in response to

that specific antigen. These antibodies are used to detect the presence of the desired

gene. These antibodies can be linked to chemicals that change color, so a simple

color change can proclaim the presence of the desired gene product.

Anticipated Problem: Where are transgenic plants tested?

VI. Genetically modified plants must be tested in a variety of ways before they can be marketed.

A. Transgenic plants are tested in growth chambers and field trials.

1. The growth chamber is a closed environment designed to control and optimize factors

that affect plant growth. This controlled environment allows researchers to test

the new plants for traits that may harm the environment, speed the growth rate of

the plants, and evaluate the expression of desired traits.

2. Field trials are conducted outside in a controlled, natural environment using normal

production techniques. Evaluation of these trials involves much data because of the

natural variability of a field. Analysis of collected data must account for the effects of

weather, soil, pests, and any other naturally occurring variable.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 8

B. Transgenic plants are evaluated in early stage testing to determine the answers to a variety of important questions, including:

1. What traits do they express?

2. Can they pollinate other plants, producing fertile offspring which might spread the

new trait into wild populations?

3. Can the transgenic plants escape to become weeds?

4. Are they effective for their intended use?

5. Will they produce unintended consequences to the environment?

C. Field trials are used to test varietal differences, farming practices, and the safety of transgenic crops.

1. Varietal trials compare transformed varieties to their normal counterpart to determine

the characteristics of the new varieties. These characteristics may include

yield, pesticide tolerance, and pest resistence.

2. Agronomic trials identify the farming practices that will give the new varieties their

best growing conditions. These can include population, row spacing, tillage practices,

or fertility programs.

3. Safety trials are used to assess any possible risk the transgenic plant may pose. These

are the same risks assessed in growth chamber trials (pollinating wild relatives,

becoming a weed). But safety trials also include looking at the potential health

effects on animals, including humans, that will consume these crops, and the potential

for the development of pest resistance in the case of insecticidal transgenic

plants.

Anticipated Problem: What are the theoretical benefits and risks of biotechnology?

VII. Biotechnology offers potential benefits and risks to the environment, global economy, and food.

A. Environmental benefits include:

1. The reduction of pesticide use

2. Greater survival of beneficial insects

3. Reduced exposure of farm workers to pesticides

4. Increased use of environmentally friendly herbicides such as glyphosate

5. Reduction of soil erosion

6. Reduced use of nitrogen fertilizer and the subsequent pollution from nitrates

7. Early detection of disease

B. Global economic benefits include:

1. More predictable yields

2. Greater yields

3. Reduced cost of production due to the use of fewer inputs

4. New markets for crops with unique traits such as pharmaceutical properties

5. Improvements to the world food supply (increased protein content, new tolerance

to environmental extremes, improved nitrogen fixation)

6. Increased efficiency in plant breeding

C. Genetically modified foods may offer the benefits of:

1. Improved protein content

2. Improved flavor

3. Improved shelf life

4. More vitamins

5. Reduction of allergens or natural toxins

6. Improved fat levels

7. Reduced pesticide residue

D. Genetically altered crops raise a number of environmental concerns including:

1. The development of insect populations resistant to this control method

2. Reduced interest in sustainable agricultural practices because of the existence of

more resistant crops

3. Difficulties in controlling weeds due to transgenic herbicide resistant crops

4. The creation of new cultivars with unknown consequences as a result of modified

crops breeding with wild plants

5. Increased use of certain herbicides with associated environmental risks inherent to

pesticide use

6. The development of disease-resistant plants resulting in more virulent strains of the

targeted pathogen

7. Poisoned wildlife

8. Reduced genetic diversity as producers become more dependant on a select group of

varieties

9. Inaccurate predictions of environmental safety from field trials

E. Economic/global concerns of biotechnology include:

1. Increased shift to more capital-intensive farming and large farms

2. Increased seed costs

3. Corporate mergers resulting in less competition among agricultural suppliers

4. Loss of ability among producers to save seed for subsequent crops

F. The concerns about biotech foods and human health include:

1. Antibiotic resistance from marker genes

2. Hidden allergens from marker genes

3. Production of new or increased levels of toxins in food crops

4. Unknown substances occurring in foods

BIOTECHNOLOGY

Part One: Matching

Instructions: For the following statements, place the letters GE in the space provided if the statement describes a characteristic of genetic engineering. Place the letter T in the space if it describes traditional plant breeding.

_______1. Requires up to 14 generations to produce a new plant

_______2. Crosses are made within the same species

_______3. A single desired gene can be inserted into a plant

_______4. Requires using the technique of backcrossing

_______5. Will produce a plant in as few as five generations

_______6. Plants are grown using tissue culture

_______7. Fewer limits to the genetic material a breeder can work with

_______8. Seeds are collected and grown to verify the results of the cross

_______9. Nearly 100,000 genes are combined

______10. Genes can be taken from any living organism

Part Two: Fill in the Blank

Instructions: Complete the following statements.

1. This recombined DNA is usually a _______________, a self-replicating closed loop that comes from a bacterium.

2. _______________ _____________ maps identify the distance between a marker and the desired gene along the strand of DNA.

3. Plant cells with no cell wall are called _______________ and are very susceptible to gene transfer.

4. The technique of ____________________ uses an electrical charge to open holes in the cell membrane.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 14

5. The risks of biotechnology include _______________, _______________, and _______________ concerns.

6. Many techniques have been developed to identify genetically transformed plants. These include the use of ______________ ____________, _______________ ____________, and _______________.

Part Three: Multiple Choice

Instructions: Circle the letter of the correct answer.

_______1. The use of living organisms to create or improve something

a. Genetic engineering

b. Biolinkology

c. Plasmology

d. Biotechnology

_______2. Which of the following is not a type of field trial?

a. Variety

b. Agronomic

c. Safety

d. Survival

_______3. A technique that is useful in culturing single-cell organisms to produce things such as insulin, antibiotics, and many vaccines

a. Immunoassays

b. Viral encoding

c. Biolistics

d. Electroporation

_______4. Involves moving genetic information from one organism into a different organism or replacing it into the original organism in a new combination

a. Genetic engineering

b. Biolinkology

c. Plasmology

d. Biotechnology

_______5. Trials that compare transformed varieties to their normal counterpart to determine the characteristics of the new varieties

a. Variety

b. Agronomic

c. Safety

d. Survival

_______6. Has either new genetic information incorporated into itself or a unique recombination of its original DNA

a. Vector

b. Protoplast

c. Transgenic organism

d. DNA probe

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 15

_______7. Maps that describe the order of the bases (ATGC) around and including the target gene on the DNA strand within the chromosome.

a. Reporter DNA

b. DNA sequence

c. Genetic linkage

d. Physical marker

_______8. The technique in which DNA is physically injected into a cell using a small glass needle

a. Biolistics

b. Microinjection

c. Electroporation

d. Vector

_______9. A living organism, such as a virus or bacterium, or a plasmid that carries new genetic information into a target cell

a. Biolistics

b. Microinjection

c. Electroporation

d. Vector

______10. A short piece of single-stranded DNA with the complimentary code for the desired gene that is labeled with radioactivity

a. Plasmid

b. Vector

c. Encoded virus

d. Protoplast

Part Four: Short Answer

Instructions: Answer the following questions.

1. List five risks and five benefits of biotechnology.

2. What are the eight major steps in creating a transgenic organism?

3. Transgenic plants are evaluated in early stage testing to determine the answers to a variety of important questions. Identify two of those questions.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 16

Assessment

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 49

TS–A

Technical Supplement

BIOTECHNOLOGY AND

GENETIC ENGINEERING

Biotechnology is simply the use of living organisms to create or improve something.

Currently, biotechnology is centered on the modification of living organisms as a

result of our new understanding of genes and DNA. It includes techniques such as

genetic engineering or recombinant DNA technology, DNA analysis, genetic mapping,

gene transfer, plant tissue culture, and biofermentation. These techniques allow scientists to locate and isolate specific genes that carry desirable traits. These genes can be moved from one organism to another without sexual reproduction. Plant tissue culture allows us to grow a whole plant from just a few cells. Biofermentation is a technique that allows the mass reproduction of modified cells. Biotechnology is being applied to microbes, plants, and animals to produce beneficial products and to improve species. It is being applied to many agricultural processes including bread making; beer brewing; wine, cheese, and yogurt fermentation; silage fermentation; and classical plant breeding. Today, much of the discussion of biotechnology centers on the area of genetic engineering.

Genetic engineering is the manipulation of genes. It also is referred to as recombinant

DNA technology. This involves moving genetic information from one organism into a different organism or replacing it into the original organism in a new combination. These changed organisms are called transgenic. A transgenic organism is one that has either new genetic information incorporated into itself or a unique recombination of its original DNA. This process allows scientists to incorporate desirable genes from any living organism into the desired plant. It also allows genetic recombination without the normal challenges of traditional plant breeding.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 50

Genetic engineering is different from traditional plant breeding in many ways. With

traditional plant breeding, crosses can be made only within the same species or

closely related species. This limits the genetic material breeders can work with.

Genetic engineering holds fewer limits to the genetic material a breeder can work

with. Genes can be taken from any living organism, including bacteria or animals,

and inserted into a plant. This opens the door to a much greater list of possible characteristics which could be incorporated into a plant. When plants are crossed using

traditional plant breeding, nearly 100,000 genes are combined from each plant. This

requires breeders to employ the technique of backcrossing, rebreeding back to one

of the original parents, often to get rid of unwanted genes and restore desired traits.

With genetic engineering, a single targeted gene can be inserted into or removed

from a plant. This makes species improvement much more precise. When a cross is

made using traditional plant breeding, the seeds are collected and the new generation

of plants must be germinated and grown before the results of the cross can be

verified. Using genetic engineering, modified plants are grown in tissue culture and

the change is verified early in the development of the plant. This greatly improves

the efficiency of the selection process. Traditional plant breeding requires up to 14

generations to produce a new plant. Genetic engineering will create a new plant in as

few as five generations. The creation of a transgenic organism begins with a selected gene from a donor organism and the insertion of that gene into a host organism. Eight major steps are required to complete this process. First, a donor is identified that contains the gene that codes for the desired trait. Next, theDNAis removed from this organism’s cells and cut into fragments.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 51

Technical Supplement

DNA FRAGMENTS

These fragments of DNA are sorted by size, using gel electrophoresis, and grouped

together. The fragment containing the desired gene is then isolated. The targeted

fragment is joined with new DNA, making it possible to move the desired gene into

the host organism. The alteredDNAis moved into the host cells using one of a variety

of techniques. This creates a cell that has been genetically transformed into a new organism. These transformed cells are grown into a complete transgenic organism.

This transgenic organism is grown and tested extensively. The transgenic organism is reproduced to assure that the new gene is transferred to the progeny with the desired results. These processes are complex and have evolved after years of research. Creating a transgenic organism begins with locating the specific gene which codes for the desired trait. Genes are specific sequences of DNA contained among the DNA inside and organism’s nucleus. In most plants and animals, fewer than ten percent of the DNA code for genes. A scientist will use a variety of mapping techniques to find a specific gene. There are three kinds of gene maps: genetic linkage maps, physical marker maps, and DNA sequence maps. Genetic linkage maps show where on the chromosome a target gene may be. It will provide the general proximity. These linkages are determined by examining the frequency that different traits are inherited together. The DNA molecule is too small to see but there are techniques that can be employed to detect its molecular characteristics. These molecular characteristics are referred to as markers. When a particular marker is found in plants that also exhibits the trait we are looking for, we say that these events are linked. Genetic linkage maps are made utilizing records of this linkage.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 52

Physical marker maps identify the distance between a marker and the desired gene

along a strand of DNA. Markers are specific molecular characteristics of the DNA

molecule which can be observed. These maps are made by cutting the DNA using

special enzymes called restriction enzymes. Each enzyme cuts the DNA at a different

spot and creates fragments of varying lengths. DNA probes are used to identify

markers on fragments. Inheritance data tells the researcher the probable location of

the gene near selected markers. Fragments are then aligned using overlapping

sequences. Using this information, a composite fragment is assembled into a map.

DNAsequence maps describe the order of the bases (ATGC) around and including

the target gene on the DNA strand within the chromosome. This can be done for a

portion of the DNA within an organism, or the whole organism can be mapped.

Projects are underway to map not only complete organisms, but complete species

genomes. Knowing the genome’s DNA sequences can be the first step in understanding

disease resistance or susceptibility, growth characteristics, and any other genetically regulated traits. Once the desired gene has been identified, it must be cut out of the donor organism and combined with other DNA before it can be inserted into the target organism. This combination is necessary for the gene to function, replicate, and be inheritable. This recombined DNA is usually a plasmid, a self-replicating closed loop that

comes from a bacterium. Once inside the host cell, the plasmid can replicate and be

passed on to the next generation. Before this can happen the target cell must be prepared

for the transformation. The target cell must remain intact after the transfer, or it will not function. These cells must not be ruptured or they will die. The tough cellulose cell wall must be penetrated and the new DNA gently moved through the cell membrane. Enzymes

can be used to digest the cell wall, creating an exposed membrane. Temporary holes

are opened in this membrane to allow gene transfer.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 53

Technical Supplement

TRANSFERRING GENES

AND CREATING GENETICALLY

MODIFIED ORGANISMS

Plant cells with no cell wall are called protoplasts and are very susceptible to gene

transfer. There are four methods commonly used to transfer genes and create genetically

modified organisms: microinjection, electroporation, biolistics, and vectors. There is also a technique referred to as viral encoding which does not create a genetically transformed organism, but does result in an organism that produces a foreign protein. With microinjection, DNA is physically injected into a cell. A small glass needle is moved through the cell membrane. After the needle has penetrated the membrane, the new DNA is simply injected into the cytoplasm. Transformed cells are grown into whole plants that exhibit the desired trait, reproduced so the offspring contains the new gene.

Electroporation involves placing a protoplast into an electrically charged environment.

This can cause the cell membrane to become permeable to DNA. The technique of electroporation uses an electrical charge to open holes in the cell membrane that allow foreignDNAto enter the cell. The transformed cells are grown and propagated, with the subsequent generations exhibiting the new trait.

Biolistics is a method of gene transfer in which DNA is shot into a cell attached to

microscopic metal particles. These particles are fired from a specially modified .22

caliber gun. The particles move so fast that they can penetrate the cell membrane

without doing permanent damage to it. Cells that survive this process are transformed

and can be grown and propagated.

Vectors are living organisms, such as a virus or bacterium, or a plasmid which carries

new genetic information into a target cell. The desirable gene is spliced into the

DNAof the vector. The vector than penetrates the target cell as part of its natural life

cycle and transforms the target cell through this infection.

Viral encoding uses a virus to carry a new gene into a cell. This gene does not

become part of the cell’s genetic make up, and so is not transferred to future generations.

While the cell is alive and infected with this virus, it will produce the protein

the new gene codes for. This technique is useful in culturing single-cell organisms

to produce things such as insulin, antibiotics, and many vaccines.

After these transformation procedures have been followed, researchers must verify

their success. Many techniques have been developed to identify genetically transformed

plants. These include the use of reporter genes or marker genes, DNA probes, and immunoassays. These methods can be used to identify a genetically modified plant at any stage of development, from seed to mature plant. The use of reporter genes is one such method. These genes are also referred to as markers or marker genes. These genes code for an observable trait and are attached to the desired gene before transfer into the target organism. If the marker gene is functioning, then the desired gene also will function. These markers are selected for traits which can be verified early in the plant’s development. DNAprobes are short pieces of single-strandedDNAwith the complimentary code for the desired gene. For example, if the gene’s DNA sequence were

ATTGCAGTT,then the probe would be TAACGTCAA. The probe is labeled with

radioactivity. If the gene is present, the probe will stick, and the radioactivity will be

detected in the transformed cell. If the gene is not present, the probe will not stick,

and there will be no radioactivity detected.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 55

Technical Supplement

IMMUNOASSAYS

Immunoassays are capable of detecting the presence of the actual desired gene without

the use of markers or radioactivity. This is accomplished by identifying the gene

product, or protein, that the desired gene produces. Immunoassays utilize techniques

working with animal immune systems involving antigens and antibodies. An

animal is injected with the target protein. This is registered as an antigen by the animal’s

immune system. The animal produces an antibody in response to that specific

antigen. These antibodies are used to detect the presence of the desired gene. These

antibodies can be linked to chemicals that change color, so a simple color change can

proclaim the presence of the desired gene product.

Once a crop is verified as having been altered genetically, it must be tested before it

can be released into the environment. Numerous tests must be conducted, and several

separate facilities are involved. Transgenic plants are tested in growth chambers

and field trials. These provide controlled environments where needed tests can be

conducted.

The growth chamber is a closed environment designed to control and optimize factors

that affect plant growth. This controlled environment allows researchers to test

the new plants for traits which may harm the environment, speed the growth rate of

the plants, and evaluate the expression of desired traits. Field trials are conducted

outside in a controlled, natural environment using normal production techniques.

Evaluation of these trials involves much data because of the natural variability of a

field. Analysis of collected data must account for the effects of weather, soil, pests,

and any other naturally occurring variable.

During this testing, many characteristics of the new plant are evaluated. Transgenic

plants are evaluated in early stage testing to determine the answers to a variety of

important questions, including: What traits do they express? Can they pollinate

other plants, producing fertile offspring which might spread the new trait into wild

populations? Can the transgenic plants escape to become weeds? Are they effective

for their intended use? Will they produce unintended consequences to the environment?

All of these questions must be answered to the satisfaction of the researchers

and various government agencies before field testing can take place. A number of

late field trials will then be conducted before the new crop is brought to market.

Field trials are used to test varietal differences, farming practices, and the safety of

transgenic crops. Varietal trials compare transformed varieties to their normal counterpart

to determine the characteristics of the new varieties. These characteristics

may include yield, pesticide tolerance, and pest resistence. Agronomic trials identify

the farming practices which will give the new varieties their best growing conditions.

These can include population, row spacing, tillage practices, or fertility programs.

Safety trials are used to assess any possible risk the transgenic plant may pose.

These are the same risks assessed in growth chamber trials (pollinating wild relatives,

becoming a weed), but also include looking at the potential health effects on

animals, including humans, that will consume these crops, and the potential for the

development of pest resistance in the case of insecticidal transgenic plants.

As research in biotechnology brings more new products to the market, society is left

to debate the risks and benefits of these innovations. Regulators ask two basic questions:

What are the theoretical benefits of biotechnology? What are the known risks

of biotechnology? In order for any new product to reach the marketplace, the benefits

must far outweigh any potential risk. This must be verified with solid scientific

investigation. Biotechnology promises a variety of benefits, but potential risks do

exist.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 57

TS–E

Technical Supplement

BENEFITS OF BIOTECHNOLOGY

Biotechnology offers potential environmental benefits, global economic benefits,

and food benefits. The environmental benefits include: the reduction of pesticide

use by incorporating pesticides into the plant; greater survival of beneficial insects

due to the reduction of broad spraying of insecticides; reduced exposure of farm

workers to pesticides; increased use of environmentally friendly herbicides, such as

glyphosate, as tolerant plants are introduced; the reduction of soil erosion through

the use of plants more tolerant to conservation practices; reduced use of nitrogen

fertilizer and the subsequent pollution of water from nitrates; and early detection of

plant disease.

In addition to these environmental benefits, the impact on the global economy must

also be considered. Global economic benefits include: more predictable yields;

greater yields; reduced costs of production due to the use of fewer inputs; new markets

for crops with unique traits such as pharmaceutical properties; improvements

to the world food supply through increased protein content, new tolerance to environmental extremes, and improved nitrogen fixation. There is also the increased

efficiency in plant breeding.

Plants that are grown for food also are being modified for improvement. Genetically

modified foods may offer the benefits of improved protein content, improved flavor,

improved shelf life, more vitamins, reduction of allergens or natural toxins,

improved fat levels, and reduced pesticide residue.

Just as benefits are considered, so too must the risks be evaluated. The risks of biotechnology include environmental, economic/global, and food concerns. Genetically

altered crops raise a number of environmental concerns. The development of

insect populations resistant to biotechnology is possible just as with any other

method of control. Resistant crops may reduce the interest in sustainable agricultural

practices. Transgenic herbicide resistant crops may become difficult to control

weeds. Modified crops may breed with wild plants to create new cultivars with

unknown consequences. There may be increased use of certain herbicides with

associated environmental risks inherent to pesticide use. The development of disease-

resistant plants will result in more virulent strains of the targeted pathogen.

There is the potential of poisoning wildlife. There may be reduced genetic diversity

as producers become more dependent on a select group of varieties. This can be

disastrous when a new pest invades an area. Field trials may not be accurate predictors

of environmental safety.

There also are risks to the global economy. An increased shift to more capital-intensive

farming and large farms may occur in some places. Seed costs will increase.

More corporate mergers will occur, resulting in less competition among agricultural

suppliers. There will be a loss of ability among producers to save seed for subsequent

crops.

The concerns about biotech foods and human health must be addressed. Antibiotic

resistance from marker genes is a concern to the human and animal health community.

Hidden allergens from marker genes may result in increased demand for more

product labeling. Production of new or increased levels of toxins in food crops is

another concern. There is a fear of unknown substances that may occur in foods.

These risks have caused concerned groups throughout the world to suggest that

genetically modified crops and the food products that contain them be labeled, giving

consumers the opportunity to avoid these products.

Even with all of the advances in technology that we have at our disposal, ethical

questions will impact the use of this technology. For agriculture to have markets for

the products it produces, the general public must be educated in the science behind

biotechnology.

Illinois Biological Science Applications in Agriculture Lesson B1–2 • Page 59

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