2024 BOT 161 Lecture 21 PDF

BOT 161: The Food-Medicine Continuum (Lecture 17)  Welcome to Theme E! Lecture 17 Chapter 21(15) Feeding A Hungry World, Plants & Society, p361-390 Chapter 22(16) Stimulating Beverages, Plants & Society, p393-410 Chapter 23(17) Herbs & Spices, Plants & Society, p411-429  Lear...

BOT 161: The Food-Medicine Continuum (Lecture 17)  Welcome to Theme E! Lecture 17 Chapter 21(15) Feeding A Hungry World, Plants & Society, p361-390 Chapter 22(16) Stimulating Beverages, Plants & Society, p393-410 Chapter 23(17) Herbs & Spices, Plants & Society, p411-429  Learning Objectives At the end of this lecture you should be able to: a) Describe the difference between food security and food insecurity. b) Understand the global disproportional distribution of food insecurity. c) Discuss the major agricultural challenges in producing enough food to feed the world’s population and how we might overcome some of these challenges. d) Describe the effects and origins of caffeine and caffeine-like alkaloids on the central nervous system. e) list the origins and importance (both good and bad) of Coffea arabica, Thea sinensis, and Theobroma cacao, plants naturally rich in caffeine, as sources of stimulating beverages.  Part A: Feeding A Hungry World Food security (Intro) Breeding for crop improvement (242) The green revolution (243) Genetic diversity (247) Biotechnology: Genetic engineering & Transgenic plants (257) What is food security? Causes of food insecurity? How severe? Number of people experiencing hunger? Regionally, Nationally & Globally. How can we improve food insecurity? SA context. Reading: Chapter 21 (15), Feeding a Hungry World Societal Problem: Burden of Food Insecurity Which of the following is an accurate description of food insecurity? A. When a person is unable to obtain a sufficient amount of healthy food on a day-to-day basis. B. When a person is unable to obtain a sufficient amount of healthy food on a month-to-month basis. C. When a person is unable to obtain a large amount of healthy food on a day-to-day basis. D. When a person is able to obtain a sufficient amount of healthy food on a day-to-day basis.  Food Security & Food Insecurity Food security: Food security refers to the state in which all people, at all times, have physical, social, and economic access to sufficient, safe, and nutritious food that meets their dietary needs and preferences for an active and healthy life. Food insecurity: a situation in which people lack reliable access to sufficient, safe, and nutritious food to meet their dietary needs for an active and healthy life.  World hunger and severe food insecurity grew, making the world's goal of achieving "zero hunger" by 2030 even more unlikely. In fact, according to current projections from the Food and Agriculture Organization of the United Nations (FAO), 8% of the world's population will still be undernourished in 2030 -- just as much as when these goals were first set in 2015. (FAO, 2023)  The 2020 State of Food Security and Nutrition in the World (SOFI) report found that, even if the effect of the COVID-19 pandemic were excluded: the world was not on track to achieve Zero Hunger, or Goal 2 of the Sustainable Development Goals preliminary indications suggested that the pandemic would add up to 132 million people to the ranks of the undernourished before the end of 2020  How will we feed 10 BILLION people? The global population has grown from 1 billion in 1800 to 8.1 billion in 2024 The human population is still growing, and the need for food will continue to increase By developing higher-yielding and disease-resistant crops, plant scientists will increase the global food supply – TARGET increase by 70% in next 40 years WATCH: How Will We Feed 10 BILLION People? Link available on clickUP https://youtu.be/0HdMtR5AkQ8 Thomas Malthus’ Theory Of Population Malthus argued that populations inevitably expand until they outgrow their available food supply, causing the population growth to be - an event causing great and often sudden damage or distress; a disaster reversed by disease, famine, war, or calamity. - a widespread scarcity of food caused by several possible factors, malnutrition and hunger-related deaths Was T.R. Malthus correct in concluding that population growth will outstrip food production growth? A. No, technological and institutional innovations have permitted food supplies to more than keep pace with population growth. B. Yes, it is only because of widespread famines that population has not overwhelmed food supplies altogether. C. No, but it is only because of the introduction of genetically modified food that supplies have kept pace with population growth. D. No, but supplies are not likely to keep pace with population growth over the next 10 years.  Threats To World’s Food Supply The Irish Famine (page 348) or the Irish Potato Famine, was a period of mass starvation and disease in Ireland (1845 to 1852) about 1 million people died and more than a million fled the country one of the greatest mass exoduses from a single island in history Images: Caused by Phytophthora infestans, a fungus wikicommons like microorganism that causes the serious potato and tomato disease - potato blight Threats to food security increase in 135 countries  Threats To World’s Food Supply Drought is often a major threat to food production Global climate change is expected to trigger droughts with a substantial impact on agriculture especially in developing nations - diminished crop growth or yield productions and carrying capacity for livestock e.g., 2015–2018 Cape Town water crisis What are the other drivers of food insecurity?  Malnutrition and Hunger Global discrepancy: Developed countries (obesity epidemic) VS Developing countries (hunger & malnutrition) Subsistence level diets are usually nutrient-poor Malnutrition is primarily a disease of poverty Our bodies need vitamins and minerals as well as calories Improved nutrient content in plants can help alleviate malnutrition Stresses Affecting Plants Cellular Response To Stress Stress Plant regulation Physiological and developmental event  Stress Tolerance In Plants How do plants respond to these stress? Certain traits make some plants more tolerant, better adapted, than others How can we exploit these traits to produce stress tolerant plants/crops? Breeding for crop improvement Artificial selection Green revolution Biotechnology (molecular biology) Cell and tissue culture Genetic engineering The process of humans identifying desirable traits in plants and then purposefully breeding individual plants with these characteristics to each other. Artificial selection - selective breeding. Breeding For Crop Improvement Ancient times – humans have practiced plant breeding by selecting for certain traits Domestication of plants artificial selection process conducted by humans to produce plants that have more desirable traits than wild plants estimated to date back 9,000- 11,000 years all principal food crops come from domesticated varieties By selectively breeding each generation, ancient farmers drastically changed teosinte's appearance, yield, grain quality and survivability—culminating in today's "corn." How is this possible? About 2500 years ago, B. oleracea was solely a wild plant that grew along the coast of Britain, France, and countries in the Mediterranean. That wild form — which still exists and is known as wild mustard Scientific Plant Breeding Gregor Mendel's experiments with plant hybridization led to his laws of inheritance (1866) only became well known in the 1900s and formed the basis of the new science of genetics, stimulated research by many plant scientists dedicated to improving crop production through plant breeding World War II, Nazareno Strampelli (Italian) created several wheat hybrids, to increase crop production (“Battle for Grain" 1925–1940) aid the foundations for Norman Borlaug and the Green Revolution Recorded evidence of plant breeding dates back to 20,000 years ago. A. True B. False  The Green Revolution – the start Plant breeding led to high-yield varieties x3 increase in crop production in 60 years These varieties need excellent growing conditions (↓stress) to be productive Fertilizers Pesticides and herbicides Mechanization Irrigation The transfer of all of this to developing nations tremendously increased food production = Green Revolution  The Green Revolution – the legacy Norman Borlaug developed wheat varieties Fed millions Nobel Peace Prize (1970) BUT not without problems (social, economic & environmental) and critics Not accessible to everyone, especially the poor High energy costs (dependent on oil) Environmental consequences N2 run-off, persistent pesticides/herbicides, pest resistance Irrigation led to increase in soil salinity Images: Population explosion, which is unsustainable? wikicommons Loss in genetic diversity Monoculture became the norm - practice of growing one crop species in a field at a time What is monoculture? Advantages & Disadvantages Which of the following does not follow monoculture? A. Dairy farming B. Mixed farming C. Plantation agriculture D. Commercial grain farming  Hunger And Malnutrition Persist New solutions are need, especially with continuing population growth Better distribution Reduced waste Innovative techniques that increase yield on the same or less land, with reduced impact on the surrounding environment Reduced –tillage Biological controls Organic fertilizers Biological fixation (Rhizobium bacteria) Dryland agriculture Better irrigation techniques (drip irrigation) Genetic engineering Which of the following is not a major problem arising out of the Green Revolution? A. Promotion of capitalist agriculture B. Increase in production and productivity C. Labour displacement D. Inter-crop imbalances E. Increase in interpersonal inequalities  Biotechnology and Plant Molecular Biology What is plant molecular biology? Study of the molecular basis of the plant. The observable characteristic, such as seed colour is known as the ……… A. genotype B. phenotype C. gamete D. inheritance  Central Dogma Of Molecular Biology DNA makes RNA, and RNA makes protein" DNA RNA Protein  Cell and Tissue Culture Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition callus – undifferentiated widely used to produce clones of a plant cells in a method known as micropropagation (mass propagation) relies on the fact that many plant cell types can regenerate a whole plant (cellular totipotency) from a single cell shoot formed from  Genetic Engineering And Transgenic plants the direct manipulation of an organism’s genes using biotechnology - genetic modification organism GMO crops have provided economic benefit to farmers in many different countries, but also a source of most of the controversy surrounding the technology South Africa grows three commercial GMO crops, mainly for herbicide and insect tolerance. The three crops are maize, cotton and soya.  Summary Comparison of conventional plant breeding with transgenic and cisgenic genetic modification The process of expression of foreign genes in a plant is called ……… A. gene expression B. transgenesis C. genetic transformation D. cell hybridization Orphan species those that could be (and in many cases have been historically) used for food on a much larger scale in diverse ecosystems  African Solution? African persimmon, marama bean, prickly pear, and marula Drought- tolerant Africa must re-adopt its orphan crops Tolerate extreme temperatures in the face of a changing environment How would you promote the acceptance of orphan crops among local communities? https://theconversation.com/africa-must-re-adopt-its-orphan-crops-in-the-face- of-a-changing-environment-78197  Part B: Stimulating Beverages Reading: Chapter 22, Stimulating Beverages  A beverage that typically contains large amounts of caffeine, and legal stimulants such as guarana, taurine, and L-carnitine Central nervous system stimulant Can increase alertness, attention, energy, as well as increase blood pressure, heart rate, and breathing  Coffee (Coffea - Rubiaceae) Earliest credible evidence of the drinking of coffee appears in modern-day Yemen from the middle of the 15th century in Sufi shrines The Yemenis procured the coffee beans from the Ethiopian Highlands via coastal Somali intermediaries and began cultivation 16th century, the drink had reached the rest of the Middle East and North Africa, later spreading to Europe. For the history of coffee please watch(link on clickUP too) https://www.youtube.com/watch?v=4U7W6fYrY uQ  Coffee (Coffea - Rubiaceae) The two most grown coffee bean types are Coffea arabica and C. robusta Coffee plants, originate from the horn of Africa, now cultivated in over 70 countries, primarily in the equatorial regions of the Americas, Southeast Asia, the Indian subcontinent, and Africa One of the few commercially cultivated crops of African origin – can you think of others? Can you think of a crop of South African origin? Coffee (Coffea - Rubiaceae) Coffee is a brewed drink prepared from roasted coffee beans, the seeds of berries from certain Coffea species The seeds are separated to produce a stable, raw product: unroasted green coffee. The seeds are then roasted, a process which transforms them into a consumable product: roasted Images: coffee wikicommons  Caffeine Around thirty plant species are known to contain caffeine Common sources are: the "beans" (seeds) of coffee plants, Coffea species (the quantity varies, but 1.3% is a typical value) cocoa plant, Theobroma cacao (chocolate) the leaves of the tea plant, Camellia sinensis kola nuts, species of plant of the genus Cola (from West Africa)  Caffeine Alkaloid = Ring + N Caffeine is an alkaloid, and is chemically related to the adenine and guanine bases of DNA and RNA Caffeine is a central nervous system (CNS) stimulant an antagonist of adenosine A2A receptors, these promotes neurotransmitter release (more on this in the next lecture) = stimulant effects It is the world's most widely consumed psychoactive drug Optional reading on clickUP Caffeine belongs to a class of chemicals called ……… A. alkaloids B. flavonoids C. theobromines D. tannins E. terpenes  Part C: Herbs And Spices Reading: Chapter 23, Herbs and Spices Why Do We Use Spices? Cornell University  Aromatics – Essential Oils Characteristic scents of aromatic plants are due to essential oils, Volatile substances that contribute to the essence or aroma of certain herbs and species A type of secondary plant product (more on this later, defence and attraction) Chemically, most essential oils are terpenes, a large group of unsaturated hydrocarbons with a common building block of C5H8 (isoprene molecule) Terpenoids – have isoprene building blocks  The Pungent Alliums A single genus, Allium from central Asia, is the source of many familiar zesty herbs: onions (A. cepa), garlic (A. sativum), leeks (A. porrum), shallots (A. ascalonicum), and chives (A. schoenoprasum) Pungent flavor and scent of onion and garlic are due to the presence of various volatile sulfur compounds Onion and garlic are two of the oldest cultivated plants used for both culinary and medicinal purposes Tulbaghia – SA’s wild garlic Two Tulbaghia (T. alliacea and T. capensis) species are predominantly used in traditional medicine in southern Africa ±24 species in SA T. violacea or T. simmleri are eaten as herb/vegetable Been shown to have antifungal and bacterial activity T. violacea Sulfur compounds – a stinky, eye- watering defense mechanism Sulfur compounds – a stinky, eye- watering defense mechanism inactive in activ in cytos vacuoles e ol Onions, garlic, allspice, and oregano were found to be the most effective for killing which of the following organisms? A. Carnivores B. Fungi C. Bacteria D. Protozoa E. Nematodes