Introduction to Plant Biotechnology

PlSc 452/552 Lecture 1 Chapter 1

C. Neal Stewart, Jr.

plantsciences.utk.edu/stewart.htmnealstewart@utk.edu

Rules for class

• Do the readings • Proper preparation prevents poor performance• Ask lots of questions • Give lots of answers• All opinions and thoughts will be heard and

respected• Grades are not awarded on the basis of need

Have fun!

Questions for the semester

• What is/are genetic engineering, transgenic plants, biotechnology?

• What is the current and potential applications?

• Risks?• Benefits?• How does plant biotechnology fit in with

modern plant breeding and agriculture?

Objectives and questions

• Define plant biotechnology.

• What biotech crops are grown and where?

• Why do farmers grow transgenic crops?

• How has the adoption of plant biotechnology impacted the environment?

• What has been plant biotech’s impact in the US and in developing countries?

Central dogma: DNARNA protein

Transgenic plants-Agrobacterium

The new plant will pass the transgeneto its progeny through seed.

Any gene, any organism

Biolistics

Consumer reports, Sept. 1999

Plant biotech milestones• 1962 Murashige and Skoog publish their

paper on tissue culture media that is very effective for tobacco and other plants

• 1982 First stably transgenic plant—marker gene in tobacco

• 1987 Gene gun invented• 1994 Flavr Savr tomato commercialized • 1996 First wide-scale planting of soybean

and corn• 2006 Billionth acre of transgenic crop

planted somewhere in the world• 2011 Second billionth acre planted

Herbicide tolerant soybean

Bt corn

Bt cotton

Progression of transgenic plants

• 1st Generation: Input traits (herbicide tolerance, insect resistance, etc.)

• 2nd Generation: Output traits: (pharmaceuticals, enhanced nutrition, etc.)

• 3rd Generation: Non-ag– (phytoremediation, sentinels, detectors)

Environmental benefits

Herbicide tolerant crops have increased and encouraged no-till agriculture– less soil erosion.

Over 1 million gallons of unsprayed insecticide per year.

Dr. Norman BorlaugNobel Peace Prize 1970

Father of the Green Revolution1914-2009

Environmental Impact Quotient (EIQ)

•Assessment of pesticide active ingredient used•Assessment of the specific pesticides used•Provides environmental impacts of individual pesticides into a single ‘field value per hectare’. •Balanced assessment of the impact of GM crops on the environment• Includes key toxicity and environmental exposure data

•related to individual products •applicable to impacts on farm workers•consumers and ecology•consistent and comprehensive measure of environmental impact.

(Kovach et al. (1992)

EIQ example

The EIQ value is multiplied by the amount of pesticide active ingredient (ai) used per hectare to produce a field EIQ value.

For example, the EIQ rating for glyphosate is 15.3. By using this rating multiplied by the amount of glyphosate used per hectare (eg, a hypothetical example of 1.1 kg applied per ha), the field EIQ value for glyphosate would be equivalent to 16.83/ha.

In comparison, the field EIQ/ha value for a commonly used herbicide on corn crops (atrazine) is 22.9/ha.

Recap and answers

• Plant biotechnology: molecular manipulation of plants and cells.

• What biotech crops are grown and where? Row crops soybean and corn for herbicide tolerance and insect resistance. US but also in 27 other countries.

• Why do farmers grow transgenic crops? More efficient and effective; better control of pests.

• How has the adoption of plant biotechnology impacted the environment? Positive—less insecticides, less soil erosion.

• What has been plant biotech’s impact in the US and in developing countries? Changed row crop genetics in US and is improving yeilds in international agriculture.

But…GM crops not universally accepted and

grown. Why?• Misunderstandings• Politics• Immature regulatory structures• Consumer issues • Benefits unclear to consumers• Fear of unknown, risk perception

Science and education should help

1996 - 1998

40

48

46

51

35

36

32

34

45

52

38

21

24

27

44

20

39

22

45

33

22

31

30

22

21

44

29

44

10

15

0 20 40 60 80 100

United Kingdom

Switzerland

Sweden

Netherlands

Italy

Germany

France

Austria

United States

Canada

Percent Response

False (Correct) Don't Know True

“Ordinary Tomatoes Do Not Contain Genes, while Genetically Modified Ones Do”

Source: Tom Hoban

“I eat organic food and drink only green tea– gallons of it when I’m writing. I smoke cigarettes, but organic ones”*

Discussing her “healthy” lifestyle in Organic Style magazine March 2005.