Introduction to Plant Biotechnology PlSc 452/552 Lecture 1 Chapter 1 C. Neal Stewart, Jr. plantsciences.utk.edu/stewart.htm nealstewart@utk.edu
Rules for class Have fun! 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 Any gene, any organism The new plant will pass the transgene to its progeny through seed.
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 Borlaug Nobel Peace Prize 1970 Father of the Green Revolution 1914-2009
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
“Ordinary Tomatoes Do Not Contain Genes, while Genetically Modified Ones Do” 1996 - 1998 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.