Domestication and Breeding 🍑🍅🥔🍆
Name a plant in the Solanaceae family and describe the importance of domestication of these plants.
Nightshade plants: tomato, potatoe, pepper, eggplant, etc.
Domestication led to non-toxic edible tissue in many nightshade plants that we eat today.
What is the main purpose of mutagenesis and transgenesis?
Methods for humans to speed up the evolutionary process to create more diversity.
Remember: Domestication and selective breeding are humans directing the evolutionary process (very slow; takes many, many generations).
What is one of the 3 main results of cooking plants? Bonus points if you can name all 3!
Chemical breakdown
Denaturing proteins
Lysis of cells
What are the two types of flowering plants? Bonus points if you can name a flower for each type.
Monocots and dicots
Cotyledon = embryonic leaf that emerges from seed
Monocots: Grasses, grains/cereal crops, lilies, etc.
Dicots: Daisies, tomatoes, peas, roses, apples, etc.
Blade: Apex, margin veins, midrib, base
Petiole
Increases in ploidy due to hybridization leads to what kind of domestication syndrome?
Fruit gigantism
What is mutagenesis and what are the two types of mutagenesis? Bonus points if you know the treatments to induce the two types of mutagenesis.
Modifying existing genes in the genome.
1. Random mutations via radiation.
2. Ploidy-related mutations via colchicine.
What is the benefit of blanching our vegetables?
Helps to improve the nutritional content of our greens by preventing chemical breakdown
What are the two life cycle phases of a plant?
Vegetative phase and reproductive phase
How are different leaf shapes formed?
Different leaf shapes are formed by controlling cell division during development.
What happens when a plant has an odd number of chromosomes per set, such as 3? Bonus points if you know what kind of ploidy this is called and if you can name a plant with this type of ploidy.
Triploid plants have to few to no seeds (sterile); ex. Bananas, seedless watermelon
What is transgenesis and what is one way we can do this?
Adding new genes into the plant genome via lateral gene transfer.
Done via Agrobacterium or gene gun (DNA-coated gold particles)
What is the benefit of lysing plant cells when we cook?
Cooking increases nutrient availability through swelling and lysis of the plant cells
You find a new plant that consists of 9 rainbow petals and parallel venation. What kind of plant would you group this in?
Monocot!
Notes: monocots have flower parts in multiples of three, parallel ventation in the leaves, fibrous roots, and scattered vascular bundles
How can you tell the difference between a leaf and a leaflet?
Leaves have a meristem at the base. Leaflets are not produces from a meristem.
Note: plants can regrow whole leaves, but not leaflets.
What were the three phenotypes Norman Borlaug achieved in wheat through selective breeding.
1. Natural resistance to rust
2. Decreased height (dwarfism)
3. High-yield production
Describe how we use transgenesis for herbicide-tolerance.
Hint: What gene is responsible for herbicide-tolerance.
Use Agrobacteria to insert glyphosate-resistant bacterial EPSP synthase gene in plant genome.
What is the benefit of cookings onions at a low temperature?
Prevents the denaturation of alliinase leading to a greater production of allicin
Name the 4 whorls of a flower. Bonus points if you can name the 3 parts of the female reproductive organ and the 2 parts of the male reproductive organ within a flower.
Sepals, Petals, Stamen, Carpel
Stamen: Filament and anther -> pollen (sperm)
Carple: Stigma, style, ovary -> ovule (egg)
How do pitcher plant curl their leaves into tubes?
Asymmetric leaf genes leads to faster cell division on one surface of the leaf causing it to curl.
What is the "center of origin" and what can we say about a crop's diversity at its center of orgin?
A center of origin is the geographical area where a crop first developed its distinctive properties.
At the center of origin, a crop plant has the highest genetic diversity.
Describe how colchicine is used to make a sterile (triploid) watermelon.
Colchicine leads to increase in ploidy by inhibiting segregation.
Use colchicine on a diploid watermelon to make a tetraploid watermelon. Cross tetraploid watermelon with a diploid watermelon to make a triploid watermelon.
Explain how transgenic broccoli can enhance the conversion of glucoraphanin to sulforaphane.
Cooking broccoli denatures myrosinase preventing the production of sulforaphane. Engineering transgenic broccoli with thermostable myrosinase can result in the production of sulforaphane at high temperatures.
What happens to a flower when you knock out the C gene?
Gene C mutants do not make anthers or carpels and leads to the development of many petals; think of the wild rose vs garden rose.
What is the name of the gene that controlls leaf shape? Bonus points if you can explain what happens when you use Agrobacteria to insert the gene into Arabidopsis.
REDUCED COMPLEXITY (RCO).
Inserting RCO into Arabidopsis will increase leave complexity.