Chapter 17 Plants to Feed the World

Overview

Hunger, starvation, and malnutrition are endemic in many parts of the world (see Chapter 8). Rapid increases in the world’s population (see Chapter 9) have intensified these problems. Because all the food that we eat comes either directly or indirectly from plants, any attempt to produce adequate food for the world’s growing human population must focus on the production of food by plants. However, the amount of land under cultivation has its geographic limits, and extending these limits carries a very high biological cost in terms of the destruction of natural ecosystems (see Chapter 18). Another way to increase crop production is to increase the yields or the nutrient content of crop species through such techniques as soil improvement, use of fertilizers and advanced irrigation techniques, pest control, and the use of different plants or new genetic strains of plants. In this chapter, we concentrate on food production by plants because that is where most of our food comes from.

Plants are essential to all of life on Earth. In addition to food, plants also provide the oxygen that humans and other organisms breathe. Without plants, most other forms of life would soon die out. Plants are the world’s richest energy source. On a worldwide basis, the amount of energy produced by plants is about 6 × 1017 kilocalories per year (abbreviated kcal/year), which is the equivalent of the energy contained in a sugar cube 5 km (or 3 miles) on each side, but, as the human population continues to increase, we are rapidly outgrowing this energy resource. This chapter discusses how plants make energy available to other organisms and how humans, through application of this knowledge, might learn to grow more crop plants and grow them more efficiently.

Chapter Outline

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Review Questions

THE PURPOSE of these review quizzes is to guide students in where their knowledge and understanding is strong, where it is weak, and where time should best be spent in studying.

CHAPTER 17:

  1. Name at least four types of commercial products derived mostly from plants.  Which is by far the most important reason why plants are grown commercially? [HDJ1] [ECM2]   How do plants obtain their energy?  How do they obtain the building blocks for their organic compounds?  Why do plants need multiple pigments?  What important molecule is split during the light reactions of photosynthesis, and what by-product is released from this reaction?  What molecule is incorporated into plant tissues during the Calvin cycle? (If you cannot explain these things, or if you are not sure, then you need to reread Section 17.1.)
  2. Why is tissue specialization important in plants?  What are the two major kinds of vascular tissue, and how do they differ?  How is water transported throughout plants, and what makes it move?  How are nutrients supplied to underground parts of plants?  (If you cannot explain these things, or if you are not sure, then you need to reread Section 17.2.)
  3. How does carbon cycle throughout the world’s ecosystems?  How does oxygen cycle?  How does nitrogen cycle?  What types of bacteria help in the nitrogen cycle?  How do certain plants (which ones?) maintain symbiotic bacteria, and how do farmers use this knowledge?  What is a limiting nutrient?  What special adaptations allow certain plants to live in nitrogen-poor habitats?  (If you cannot explain these things, or if you are not sure, then you need to reread Section 17.3.)
  4. How are crop yields increased?   What fertilizers are most commonly used?  What are some major problems with chemical fertilizers?  How can soil be enriched without chemical fertilizers?  What is hydroponics?  What are some advantages and disadvantages of hydroponics?  What is a monoculture, and what are some drawbacks of monoculture?  What are some common methods of pest control, and what problems arise with these methods?  What does IPM stand for, and what are some of its principles?  What is biomagnification?  (If you cannot explain these things, or if you are not sure, then you need to reread Section 17.4.)
  5. How can plant genomes be altered?  Explain at least three methods that have been used for this purpose.  What are some existing uses of transgenic plants?  What is ‘molecular farming’?   What are some concerns about the increased use of transgenic plants?  (If you cannot explain these things, or if you are not sure, then you need to reread Section 17.5.)

Open Response Study Questions

These questions are designed to assess your understanding of the topics explored in this chapter. You can use these questions in three ways:

Before you start …

Read through the questions before you read the chapter to help prime you to read the text more carefully and strategically. Remember that you are just starting out on your learning journey, so don’t feel disheartened if you don’t know how to answer them yet!

Whilst you read …

As you work through the chapter, have another go at answering the questions to see how you are progressing. You can also answer the questions with the textbook open in front of you, in order to create model answers that can be used to refer back to later.

At the end …

Answer the questions once you have finished reading to see what you have learned. Check your responses against your model answers and use these to identify any gaps in your understanding.

DEFINITIONS:

In your own words, define ANY TWO of the following terms:

economic impact level            limiting nutrient          Integrated Pest Management (IPM)

decomposers                           drip irrigation             hydroponics            eutrophication

ESSAYS:

Answer any two of the following questions.  Make sure to answer all parts of any question you choose.

1. Explain Integrated Pest Management, including (A) What is it?  (B) Why is it used?  (C) What are its major costs and benefits?

2. Explain: (1) why plants need nitrogen;  (2) how most plants get their nitrogen;  (3) what it means to say that nitrogen is a “limiting nutrient” to a particular crop;  (4) at least one unusual adaptation that some plants have evolved to get their nitrogen;  and (5) how crop rotation can help supply nitrogen to crops.

3. Explain why vascular plants can grow in many habitats in which nonvascular plants cannot survive.

4. What are some consequences (describe at least two) of the overuse of fertilizers?

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Bibliography

Agre P. et al. [including 141 Nobel laureates as of 2018].  2016.  Laureates Letter Supporting Precision Agriculture (GMOs).  Http://supportprecisionagriculture.org/nobel-laureate-gmo-letter_rjr.html

Ali, M.A., et al. 2017.  Transgenis strategies for enhancement of nematode resistance in plants.  Front. Plant Sci., Sec. Plant Biotechnology, vol. 8, 09 May 2017. https://doi.org/10.3389/fpls.2017.00750

Alscher, R.G., and J.R. Cumming. 1990. Stress Responses in Plants: Adaptation and Acclimation Mechanisms. New York: Wiley-Liss.

Arpaia, S. et al. 2020. Biosafety of GM crop plants expressing dsRNA: data requirements and EU regulatory considerations.  Front. Plant Sci., 24 June 2020. https://doi.org/10.3389/fpls.2020.00940

Benton, J.J. 1983. A Guide for the Hydroponic and Soilless Culture Grower. Portland, OR: Timber Press

Bottrell, D.R. 1979. Integrated Pest Management. Washington, DC: Superintendent of Documents, U.S. Government Printing Office.

Bruening, G. 1987. Tailoring Genes for Crop Improvement: An Agricultural Perspective. New York: Plenum Press

Briggs, D., and S.M. Walters. 1984. Plant Variation and Evolution. Cambridge: Cambridge Univ. Press

Canny, M.J. 1998. Transporting water in plants. Amer. Sd. 86: 152-159.

Carson, R. 1962. Silent Spring. Boston: Houghton Mifflin.

Center for Food Safety. 2021. About genetically engineered foods.  https://www.centerforfoodsafety.org/issues/311/ge-foods/about-ge-foods

Chrispeels, M.J. and D.E. Sadava. 1994. Plants, genes, and agriculture. Boston, MA: Jones and Bartlett.

Clark M., Tilman D.  2017.  Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice.  Envir. Research Lett. 12(6)   http://iopscience.iop.org/article/10.1088/1748-9326/aa6cd5/meta;jsessionid=A255BA8C9BC2AFDF39F1EB2DB7BE1567.c4.iopscience.cld.iop.org

Committee on Environmental Impacts associated with Commercialization of Transgenic Plants, Board on Agriculture and Natural Resources, Division on Earth and Life Sciences, National Research Council. 2002. Environmental effects of transgenic plants: the scope and adequacy of regulation. Washington, DC: National Academy Press.

Crawley, M.J., editor. 1986. Plant Ecology. Oxford: Blackwell Scientific.

Davies, J, and W.S. Resnikoff. 1992. Milestones in Biotechnology: Classic Papers on Genetic Engineering. Boston: Butterworth-Heinemann.

Dixon, R.O.D., and C.T. Wheeler. 1986. Fixation in Plants. Glasgow: Blackle.

Dodds, J.H. 1985. Plant Genetic Engineering. New York: Cambridge University Press

Dover, M.J. 1985. A Better Mousetrap: Improving Pest Management for Agriculture. Washington, DC: World Resources Institute.

Dudley, J.W., and R.J. Lambert. 2004. 100 generations of selection for oil and protein in corn.  Plant Breeding Rev. 24(1): 79-110.

EAT-Lancet Commission. 2019.  Summary Report of the EAT-Lancet Commission.  https://eatforum.org/content/uploads/2019/01/EAT-Lancet_Commission_Summary_Report.pdf

Environmental Protection Agency. 2021. Integrated pest management (IPM) principles.  https://www.epa.gov/safepestcontrol/integrated-pest-management-ipm-principles

Fitter, A.H., and R.K.M. Hay. 1981. Environmental Physiology of Plants. New York: Academic Press.

Flint, M.L. 1998. Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control. Berkeley, CA: University of California Press.

Fox, M.W. 1992. Superpigs and Wondercorn. The Brave New World of Biotechnology and Where it All May Lead. New York: Lyons & Burford.

Fu, L., and Gendel, S.M., eds. 2002. Genetically engineered foods: assessing potential allergenicity. Annals N.Y. Acad. Sciences, vol. 964. New York, NY: New York Academy of Sciences.

Glover, D.M., editor. 1985. DNA Cloning. A Practical Approach. 2 vols. Washington, DC: IRL Press

Grierson, D., and S.N. Covey. 1988. Plant Molecular Biology, 2nd ed. Glasgow: Biocide.

Grunewald W., and Bury J.  2016.  The GMO Revolution.  Leuven, Belgium:  LannooCampus Publishers.  [EDITOR:  LannooCampus is written as one word.]

Harlan, J.R. 1992. Crops and Man, 2nd ed. Madison, WI: American Society of Agronomy.

Hedin, P.A., editor. 1985. Bioregulators for Pest Control. Washington, D.C.: American Chemical Society.

Horn, DJ. 1988. Ecological Approach to Pest Management. New York: Guilford Press

Huffaker, C.B., and R.L. Rabb, editors. 1984. Ecological Entomology. New York: John Wiley.

IPM Institute of North America. 2021. What is integrated pest management?  https://ipminstitute.org/what-is-integrated-pest-management/

Jeffrey, D.W. 1987. Soil-Plant Relationships. An Ecological Approach. Portland, OR: Timber Press

Kluger, J. 1999. The suicide seeds. Time Feb. 1, 1999: 44-45.

Kung, S D , and R. Wu, editors. 1993. Transgenic Plants. New York: Academic Press. 2 vols.

Lambrecht, B. 2001. Dinner At The New Gene Cafe: How Genetic Engineering Is Changing What We Eat, How We Live, And The Global Politics Of Food. New York: Thomas Dunne Books.

Lancet.  2017.  Editorial: Sustainable food for a sustainable planet.  The Lancet Planetary Health 1(4): PE123.  https://doi.org/10.1016/S2542-5196(17)30066-9 https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(17)30066-9/fulltext

Larson, D.W. 1996. Curing the incurable. Amer. Sci. 84: 7-9.

Levin, M.A., and H.S. Strauss. 1991. Risk Assessment in Genetic Engineering. New York: McGraw-Hill.

Lim, H.A. 2002. Genetically Yours: Bioinforming, Biopharming, Biofarming. River Edge, NJ: World Scientific.

Low, L.Y., et al. 2018. Transgenic plants: gene constructs, vector and transformation method. In: O. Celik, editor, New Visions in Plant Science. London: IntechOpen.  [EDITOR: IntechOpen is one word, with capitalized I and O.]

Marco, G.J., R.M. Hollingworth, and W. Durham, editors. 1987. Silent Spring Revisited. Washington DC: American Chemical Society.

Martineau, B. 2001a. Food fight: The short, unhappy life of the Flaw Savr tomato. The Sciences Spring 2001 24-29.

Martineau, B. 2001b. First fruit: the creation of the Flavr Savr tomato and the birth of genetically engineered food. New York, NY: McGraw-Hill.

Marvier, M. 2001. Ecology of transgenic plants. American Scientist 89: 160-167.

Meyer W.K. et al. 2018.  Ancient convergent losses of Paraoxonase-1 yield potential risks for modern marine mammals.  Science, 361(6402): 591-594.

Miller, G.T. 1992. Living in the Environment. Belmont, CA: Wadsworth Publishing Co.

Mooney, H.A. and G. Bernardi. 1990. Introduction of genetically modified organisms into the environment. Chichester, U.K.: John Wiley & Sons.

Moore, S.K. 1997. Natural synthetics. Sci. Amer. Feb.: 36-37.

Nester, E. 2008. Agrobacterium, the natural genetic engineer 100 years later. APSnet Features. https://doi.org/10.1094/APSnetFeatures-2008-0608

Nester, E., M.P. Gordon, and A. Kerr, editors. 2005. Agrobacterium tumefaciens: From Plant Pathology to Biotechnology. St. Paul, MN: American Phytopathological Society.

Norman A, Aqeel M, He S.  2016. CRISPR-Cas9: Tool for Qualitative and Quantitative Plant Genome Editing.  Frontiers in Plant Sci., Nov. 21, 2016.  https://doi.org/10.3389/fpls.2016.01740

Nottingham, S. 1998. Eat your genes: how genetically modified food is entering our diet. London: Zed Books Ltd.

Pence, G.E. 2002. Designer food: mutant harvest or breadbasket of the world? Lanham, MD: Rowman & Littlefield.

Pramer, D. 2000. Statement of the American Society for Microbiology on genetically modified foods. ASM News 66: 590-591.

Rissler, J. and M. Mellon. 1996. The ecological risks of engineered crops. Cambridge, MA: MIT Press.

Roberts R.J.  2018.  The Nobel Laureates’ campaign supporting GMOs.  J. Innovation Knowledge  3(2): 61-65.

Ronald, P.C. 1997. Making rice disease-resistant. Sci. Amer. Nov.: 100-105.

Salunkhe, D.K., and S.S. Deshpande, editors. 1991. Foods of Plant Origin. New York: Van Nostrand Reinhold.

Slack, A. 1980. Carnivorous Plants. Cambridge, MA: MIT Press

Teitel, M., K.A. Wilson, and R. Nader. 1999. Genetically Engineered Food: Changing the Nature of Nature. Rochester, VT: Park Street Press

Tyler, V.E., L.R. Brady, and J.E. Robbers. 1976. Pharmacognosy, 7th ed. Philadelphia Lea & Febiger.

U.S. Department of Agriculture. 2020. Recent trends in GE adoption. https://www.ers.usda.gov/data-products/adoption-of-genetically-engineered-crops-in-the-us/recent-trends-in-ge-adoption.aspx

U.S. Food and Drug Administration. 2020. How GMO crops impact our world. https://www.fda.gov/food/agricultural-biotechnology/how-gmo-crops-impact-our-world

Winston, M.L. 2002. Travels in the Genetically Modified Zone. Cambridge, MA: Harvard University Press

Wolkomir, R. 1997. Unearthing secrets locked deep inside each fistful of soil. Smithsonian Mar.: 74-83.

Woodworth, C.M., E.R. Leng, and R.W. Jugenheimer. 1952. Fifty generations of selection for oil and protein content in corn.  Agron. J. 44: 60-65.

Chapter 18
Biodiversity and Threatened Habitats