Plant Nutrition and Defense Flashcards
What types of nutrients does the soil provide for a plant?
macro and micro elements
What are macroelements?
elements that are needed in surplus
What are microelements?
elements that are not needed as much
Explain soil ion exchange?
- soil is mostly negative, therefore, anions from fertilizer are more attracted to the positive root hairs
- however, because the soil is already negative, the excess anions have a tendency to get washed away
- therefore, in order to get nutrients (and positive charge), we exchange a H+ ion for a proton
Is symbiosis with Rhizobia rare or common?
rare
What does rhizobia do for legumes?
fixes nitrogen
How does the rhizobia get into the legume?
bacteria is invited in and it takes over a division of cortical tissue
What does the rhizobia get in exchange?
oxygen
Is symbiosis with mycorrhizae rare or common?
common
What does mycorrhizae allow plants to do?
absorb phosphates and micronutrients and helps protect plants from disease
What does the mycorrhizae get in return?
carbs
What type of environment do carnivorous plants live in?
nitrogen poor environments
How do carnivorous plants get nitrogen?
they attract, trap, and digest insects to get nitrogen
What do parasite plants do?
they extract nutrients from host plants
Can parasitic plants do photosynthesis?
sometimes
What is the first layer of defense for plants?
dermal
What are chemical defenses?
defenses that always are there and need to be maintained
What are cyanogenic glycosides?
chemical defenses that are related only when the plant is damaged because it can actually hurt the plant
What are plant defenses?
first layer of chemical defenses that defends against microbes
What are secondary metabolites?
toxins or other natural producing substances that give plants a competitive edge, and they are not associated with growth or development
What are allelopathic plants?
when the chemicals from one plant impact another plant
What is an example of an allelopathic plant?
when a plant secrets chemicals to stop seed germination, in order to reduce competition
What is an example of two distinct animal helpers?
acacia trees and ants // parasitoid wasps
What do ants do for acacia trees?
when an organism get close to trees, ants swarm animals that come near (this is because the nectar of the acacia tree is addicting to ants)
What do parasitoid wasps do?
when caterpillar eat leaves, the plant releases a compound that attracts female parasitoid wasps, and when larve hatches the wasps eat the caterpillars
What are inducible defenses?
defenses that are only initiated in the presence of an actual threat
Is the energy cost of inducible defenses lower or higher than chemical defenses?
lower
What is an example of an inducible defense?
tomatoes and jasmonic acid
How does jasmonic acid work in tomatoes?
- attacked tomato produces a hormone called systemin
- system moves through the phloem, and binds to receptors
- the receptors signal the production of jasmonic acid
- jasmonic acid turns on proteinase inhibitors so that plants are not so digestible
What is the gene for gene hypothesis?
a way that plants recognize and store information about pathogens
What are the steps for gene for gene hypothesis?
- pathogens have avr genes
- plants have resistance gene (R)
- if R detects avr, a hypersensitive response will occur and the disease doesn’t affect the plant
What is a hypersensitive response in plants?
where plants kill off currounding tissue to isolate an infection
What is a systemic acquired response?
a signaling molecule is sent to healthy tissue to warn of infection
