Plant Movement, Growth, Signaling. Hormones And Nutrients Flashcards
Macro Nutrients
N- nitrogen
P- phosphorus
K- potassium
Secondary elements
Ca- calcium
Mg- magnesium
S- sulphur
Micro elements
Fe- iron
B- boron
Zn- zinc
Cu- copper
Mn- manganese
Mo- molybdenum
Ectomycorrhiza
Beneficial fungus on the outside of roots
Arbuscular mycorrhiza
Beneficial fungal structure under the epidermal cells
Benefits of am colonization
Increased resistance to dollar pathogens
Increased drought tolerance
Increased salt tolerance
SaR like responses
Resistance to root pathogens
Resistance to heavy metals
Systemic resistance to root pathogens
Passive transport
Diffusion
Facilitated diffusion
Active transport
Requires ATP
How do roots absorb nutrients?
-H+ ions actively transported out of vacuoles of root cells into soil
-H+ ions displace minerals from clay particles, which diffuse into root along concentration gradient
-Clay particles are negatively charged bind to cations
-cations exchanged for hydrogen
- minerals are released into the soil solution
Potassium
-In photosynthesis regulates the opening and closing of stomata, therefore regulating CO2 uptake
- triggers activation of enzymes, is essential for production of ATP
Magnesium and Nitrogen in chlorophyll
Chlorophyll is one mg surrounded by nitrogen then by carbon any hydrogen, then a hydrophobic tail
Phosphorus and Nitrogen in ATP
Three phosphates = ATP
Two phosphates = ADP
Phosphorus and Nitrogen in DNA and RNA
Phosphorus in the sugar phosphate backbone
Nitrogenous bases of DNA and RNA
Nitrogen into proteins Amino acids
Amino acids- r group Amino group and carboxyl group
Nitrogen cycle
(Photo in slides)
Cow poops it leaches into the ground to become ammonium (NH4)
Nitrogen fixing bacteria change it to ammonia. (NH3)
Nitrifying Bacteria convert it to NO3
Assimilation
Denitrifiation bacteria
Nitrogen fixing bacteria
On roots of plants
They get photosynthesis products from plants
they give nitrogen compounds from the air to the roots
Root nodules
Occurs when a plant makes a home for their Nitrogen fixing Bacteria friends
Hormones
Chemical signals
From the Greek word Horman “to stimulate
Regulate metabolism, growth and it only takes a little bit
Can control expression of specific genes
Auxins
Produced in apical meristems of shoots
Moves downward in stem to roots
Controls cell elongation
Hormone that plays a role in vascular tissue differentiation?
Auxins
Hormone that promotes formation of lateral and adventitious roots?
Auxins
Hormone that inhibits growth of lateral buds?
Auxins
Hormone that promotes fruit development by instigating maturation of the ovary wall?
Auxins
Cytokinins
Discovered in coconut milk
Promotes cell division
Named for involvement in cytokinesis
Travels from apical meristem of roots up into plant
Hormone most abundant in actively dividing tissues like seeds, fruits, and leaves?
Cytokinins
Hormone that works with and balances the effects of auxins?
Cytokinins
Hormone produced in the roots that promotes cell division?
Cytokinins
Ethylene
- Gas- a simple hydrocarbon CH2=CH2
- Major influence on most aspects os plant growth and development
-Usually inhibits cell elongation
-Promotes fruit ripening - promotes abscission
- Mechanical wounding and environmental stresses can stimulate production
What hormone promotes fruit ripening?
Ethylene
What hormone promotes abscission?
Ethylene
What hormone is stimulated by mechanical wounding and environmental stresses?
Ethylene
Abscisic Acid (ABA)
Growth inhibiting hormone in dormant buds, fruits, and embryos.
Induces dormancy.
What hormone induces dormancy?
Abscisic Acid (ABA)
What hormone stimulates stomata closure when water is scarce?
Abscisic Acid, (ABA)
What part of the plant is Abscisic Acid produced in?
Produced by roots, released by xylem
Gibberellins
Stimulate growth of stems
Both cell division and cell elongation
What hormone is active in both cell division and cell elongation?
Gibberellins
What hormone is responsible for the growth of stems?
Gibberellins
What hormone stimulates seed germination by stimulating digestive enzymes?
Gibberellins
What are other external factors that affect plant growth or movement?
Tropisms
Nastic movements
Tropisms
Directional growth in response to an external stimulus
Phototropism
Gravitropism or geotropism
Thigmotropism
What is the curving of light toward the light?
Positive phototropism
What is the curving of roots away from the light?
Negative phototropism
Phototropism
Photoreceptor for this response is a pigment containing protein that absorbs blue light and converts signal into a biochemical response
Involves Auxin
What tropism involves the lateral migration of auxin under the influence of light?
Phototropism
Auxin is made in stem and leaves and travels down the stem
Auxin makes cells elongate on the opposite side of the light, or the shady side, causing a curving toward the light
Gravitropism
Response of a shoot or a root to gravity
Movement of auxin to lower surface of a horizontally oriented shoot or root promotes the upward curvature of a shoot or the downward curvature of a root.
Auxin stimulates cell elongation is shoots and inhibits cell elongation in roots
What is the starch-statholith hypothesis?
Involves small particles sinking to the bottom of the amyloplasts telling the plant which way is down
Thigmotropism
Response to contact with a solid object
Greek word “thigma” means touch
Enables roots to grow around rocks
Enables shoots to wrap around structures, like tendrils
Heliotropism
Leaves and flowers orienting themselves to face suns rays
Solar tracking
Greek word “helio” means sun
Not due to cell growth or elongation
Change of water potential in cells of Pulvini (specialized areas of leaves of certain plants)
Nastic Movements
Movements that occur in response to stimulus with direction of movement being unrelated to the direction of the stimulus
Very quick and unrelated to cell growth
Osmotic Motors results from turbot changes in cells (motor cells of pulvini
Related to and increased concentration of sugars which decreases water potential in the cells and can involve K+ and Cl-
