Plant Prt 3: Immunity and Teosinte Flashcards
(21 cards)
Give the general disease cycle of a plant:
Infection → Disease Development → Inoculum production → Dispersal to other plants OR in the same plant
What is the 1st defence layer of the plant
(1st defense) Physical - cell walls, waxy cuticle, bark, strong barriers
What responses of the plant make up the second defence layer in its immune system?
Immune responses (2nd defense): 1st layer - PAMP-triggered immunity & PRR response
2nd layer - Effector-triggered immunity (Hypersensitive response and systemic acquired resistance)
What is Methylsalicylic acid and how does it help the plant from herbivore attack?
Methylsalicylic Acid (SAR) - systematic response; before the cells die from hypersensitive response, methyl salicylate acid is transported to the rest of the plant.
What is Salicylic acid, how does it relate to methylsalicylic acid and how does it help the plant from herbivore attack?
Salicylic Acid - After Methylsalicylic acid is transported to the rest of the plant, cells away from the infection convert MSA into salicylic acid, inducing systemic acquired resistance and activating defence genes.
What structure of a plant is both physical and chemical defence?
Trichomes: hair-like structures with physical and chemical defence using a granular tip.
Non-glandular trichomes create physical barriers that make it hard for insects to reach the surface. Glandular tips secrete toxic or sticky chemicals.
What is JA and how does it help protect the plant from attack?
Jasmonic Acid (JA) - triggers cascade of chemicals from chewing herbivores.
When attacked the JA pathway is activated, causing a cascade of chemicals, leading to changes in gene expression and the production of defensive compounds that deter herbivores from continuing to eat (or it just kills them)
What is VOC and how does it help protect the plant? What are the steps?
Indirect defense - Volatile Organic Compounds: attracts predators of herbivores
Plant gets chewed on → plant releases attracting compounds for certain predator → predator is attracted → predator eats prey herbivore on plant
What are the origins of plant agriculture?
Wild Gathering - useful wild plants
Semi-settled migration - grow plants near settlements (cultivation)
Permanent Settlements - adding in artificial selection to domesticate plants
what are desirable traits for fruit producing plants?
more food, no abscission, all synchronized fruiting and flowering (determinate growth), mroe attractive color and size.
What are desirable traits for grain producing plants?
Grains - no vernalization, more seeds, reduced seed shatter and plant height, reduced dormancy.
give an example of a domesticated plant that we use today:
Teosinate - corn wild plant ancestor
Teosinte:
Very hard kernels
Very hard fruit covering
Very branched stalks
Differed only by 4-5 regulatory genes:
Teosinte branched 1 (tg1) - controls branching patterns (stalks) and inflorescence (number of kernels)
Teosinte glume architecture 1 (tga1) - structure of seed casting cover
What are three most common crop family names? What kind of crops are these?
Poaceae (rice) - grass family (cereals)
Solanaceae (potatoes) - nightshade family including tomatoes and eggplants
Fabaceae (beans) - legume family including beans, peas, and foraged crops clover
Staple crops - most commonly grown and consumed
How can we address the increase in Human Population’s need to eat?
Diversify Diets - utilized crops used to reduce demand of stample crops
Indoor Growing/ Vertical Farming
Implement new technology for breeding and crop improvement
Explain Traditional Breeding, what it does, and how it can be regulated:
-Desired genes inserted with other genetic material (crossing)
-few genes affected
-No safety testing requried - unregulated
Explain Mutagenesis, how it can be regulated, and what it changes in a plant?
-exposing seed to radiation and chemicals
-random changes to genome (usually unpredictable)
-~100 to 1,000 genes affected
Unregulated and no required safety testing
What is transgenetics, waht does it change in a plant, and how is it monitered?
-inserting selected genes using recombinant DNA
-only genes instered at desired locations
- 1-8 genes affected
-Highly regulated and safety tests required
What is gene editing, what does it change, and how is it monitered?
-Desired genes deleted only at known locations
-Only ~1 gene affected
-Safety required with mixed regulations
who hypothesized that teosinte is the ancestor of maize? What is the evidence?
George Bettle - found a grass called Teosinte that is the ancestor of Corn.
Both corn and Teosinte had nearly identical chromosomes and could produce highly fertile offspring.
Teosinte - Only the ear has a few kernels with a VERY hard fruit case.
About 1/500 plants were identical to maize - means that changes in just 4-5 genes were responsible for change in plants
Microfossils were found on the ground stones that allowed to find the difference of form vs teosinte.
Showed that people in Balsas river area used teosinte with the oldest date being 8,700 ya
First cultivations of Teosinte used like popcorn - by popping fruit cases they were able to make popcorn
What kind of genes were changed that allowed for teosinte to very easily become corn?
Regulator Genes - directly regulate the expression of other genes.
Because of these differences in genes between Teosinte vs Corn, only a few changes were necessary to change.
