Mineral Nutrition Studied by soilfree culture in nutrient
Mineral Nutrition Studied by soil-free culture in nutrient solutions:
Mineral Nutrition Studied by soil-free culture in nutrient solutions: Hoagland’s is best known
Mineral Nutrition Soil-free culture • Sand culture: don’t really control nutrients
Mineral Nutrition Soil-free culture • Sand culture: don’t really control nutrients • Hydroponics: immerse roots in nutrient solution
Mineral Nutrition Soil-free culture • Sand culture: don’t really control nutrients • Hydroponics: immerse roots in nutrient solution • Rapidly deplete nutrients & O 2 & alter p. H
Mineral Nutrition Soil-free culture • Sand culture: don’t really control nutrients • Hydroponics: immerse roots in nutrient solution • Rapidly deplete nutrients & O 2 & alter p. H • Slanted film maintains [nutrients] & O 2
Mineral Nutrition Soil-free culture • Sand culture • Hydroponics: immerse roots in nutrient solution • Slanted film maintains [nutrients] & O 2 • Aeroponics sprays nutrient solution on roots
Mineral Nutrition Macronutrients • CHOPKNS
Mineral Nutrition Macronutrients • CHOPKNS • CHOPNS make biopolymers
Mineral Nutrition Macronutrients • CHOPNS make biopolymers • N deficiency • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients • CHOPNS make biopolymers • P deficiency • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients • CHOPNS make biopolymers • S deficiency • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients • CHOPKNS • CHOPNS make biopolymers • K makes turgor, enzyme cofactor • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients • CHOPKNS • Ca: signaling, middle lamella, cofactor • immobile in plant, so shows first in young leaves
Mineral Nutrition Macronutrients • Ca: signaling, middle lamella, cofactor • Fe: cofactor • immobile in plant, so shows first in young leaves
Mineral Nutrition Macronutrients • Ca: signaling, middle lamella, cofactor • Fe: cofactor • Mg: cofactor • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients: CHOPKNSCa. Fe. Mg • Ca: signaling, middle lamella, cofactor • Fe: cofactor • Mg: cofactor • mobile in plant, so shows first in old leaves
Mineral Nutrition Macronutrients: CHOPKNSCa. Fe. Mg. BNa. Cl • Ca: signaling, middle lamella, cofactor • Fe: cofactor • Mg: cofactor • mobile in plant, so shows first in old leaves
Mineral Nutrition Micronutrients: BNa. Cl • B: cell elongation. NA metabolism • immobile in plant, so shows first in young leaves
Mineral Nutrition Micronutrients: BNa. Cl • B: cell elongation. NA metabolism • Na: PEP regeneration in C 4, K substitute • mobile in plant, so shows first in old leaves
Mineral Nutrition Micronutrients: BNa. Cl • B: cell elongation. NA metabolism • Na: PEP regenerationin C 4, K substitute • Cl: water-splitting, osmotic balance • mobile in plant, so shows first in old leaves
Mineral Nutrition Micronutrients: BNa. Cl others include Cu, Zn, Mn • B: cell elongation. NA metabolism • Na: PEP regeneration, K substitute • Cl: water-splitting, osmotic balance • Cu: cofactor • immobile in plant, so shows first in young leaves
Mineral Nutrition Commercial fertilizers mainly supply NPK
Plant food • 2. 6% ammoniacal nitrogen • 4. 4% nitrate nitrogen • 9% phosphorus • 5% potassium • calcium (2%) • magnesium (0. 5%) • sulfur (0. 05%) • boron (0. 02%) • chlorine (0. 1%) • cobalt (0. 0015%) • copper (0. 05%) • iron (0. 1%) • manganese (0. 05%) • molybdenum (0. 0009%) • nickel (0. 0001%) • sodium (0. 10%) • zinc (0. 05%)
Mineral Nutrition Soil nutrients • Amounts & availability vary PSU extension Text
Mineral Nutrition Soil nutrients • Amounts & availability vary • Many are immobile, eg P, Fe
Mineral Nutrition Soil nutrients • Amounts & availability vary • Many are immobile, eg P, Fe • Mobile nutrients come with soil H 2 O
Mineral Nutrition Soil nutrients • Amounts & availability vary • Many are immobile, eg P, Fe • Mobile nutrients come with soil H 2 O • Immobiles must be “mined” • Root hairs get close
Mineral Nutrition Immobile nutrients must be “mined” • Root hairs get close • Mycorrhizae get closer
Mineral Nutrition Immobile nutrients must be mined • Root hairs get close • Mycorrhizae get closer Solubility varies w p. H
Mineral Nutrition • Solubility varies w p. H • 5. 5 is best compromise
Mineral Nutrition Solubility varies w p. H • 5. 5 is best compromise • Plants alter p. H @ roots to aid uptake
Mineral Nutrition Nutrients in soil • Plants alter p. H @ roots to aid uptake • Also use symbionts • Mycorrhizal fungi help: especially with P
Mineral Nutrition Also use symbionts • Mycorrhizal fungi help: especially with P • P travels poorly: fungal hyphae are longer & thinner
Mineral Nutrition Also use symbionts • Mycorrhizal fungi help: especially with P • P travels poorly: fungal hyphae are longer & thinner • Fungi give plants nutrients
Mineral Nutrition Also use symbionts • Mycorrhizal fungi help: especially with P • P travels poorly: fungal hyphae are longer & thinner • Fungi give plants nutrients • Plants feed them sugar
Mineral Nutrition Also use symbionts • Mycorrhizal fungi help: especially with P • P travels poorly: fungal hyphae are longer & thinner • Fungi give plants nutrients • Plants feed them sugar • Ectomycorrhizae surround root: only trees, esp. conifers
Mineral Nutrition Ectomycorrhizae surround root: only trees, esp. conifers • release nutrients into apoplast to be taken up by roots
Mineral Nutrition Ectomycorrhizae surround root: trees • release nutrients into apoplast to be taken up by roots Endomycorrhizae invade root cells: Vesicular/Arbuscular • Most angiosperms, especially in nutrient-poor soils
Mineral Nutrition Endomycorrhizae invade root cells: Vesicular/Arbuscular • Most angiosperms, especially in nutrient-poor soils • May deliver nutrients into symplast
Rhizosphere Endomycorrhizae invade root cells: Vesicular/Arbuscular • Most angiosperms, especially in nutrient-poor soils • May deliver nutrients into symplast • Or may release them when arbuscule dies
Rhizosphere Endomycorrhizae invade root cells: Vesicular/Arbuscular • Most angiosperms, especially in nutrient-poor soils • Deliver nutrients into symplast or release them when arbuscule dies Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere
Rhizosphere Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere • Plants feed them lots of C!
Rhizosphere Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere • Plants feed them lots of C! • They help make nutrients available
Rhizosphere Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere • Plants feed them lots of C! • They help make nutrients available • N-fixing bacteria supply N to many plant spp
Nutrient uptake Most nutrients are dissolved in water
Nutrient uptake Most nutrients are dissolved in water • Enter root through apoplast until hit endodermis
Nutrient uptake Most nutrients are dissolved in water • Enter root through apoplast until hit endodermis • Then must cross plasma membrane
Crossing membranes A) Diffusion through bilayer B) Difusion through protein pore Selective C) Facilitated diffusion D) Active transport E) Bulk transport Active 1) Exocytosis 2) Endocytosis
Nutrient uptake Then must cross plasma membrane • Gases, small uncharged & non-polar molecules diffuse
Nutrient uptake Then must cross plasma membrane • Gases, small uncharged & non-polar molecules diffuse down their ∆ [ ] • Important for CO 2, auxin & NH 3 transport
Nutrient uptake Then must cross plasma membrane • Gases, small uncharged & non-polar molecules diffuse down their ∆ [ ] • Polar chems must go through proteins!
Selective Transport 1) Channels integral membrane proteins with pore that specific ions diffuse through
Selective Transport 1) Channels integral membrane proteins with pore that specific ions diffuse through • depends on size & charge
Channels integral membrane proteins with pore that specific ions diffuse through • depends on size & charge • O in selectivity filter bind ion (replace H 2 O)
Channels integral membrane proteins with pore that specific ions diffuse through • depends on size & charge • O in selectivity filter bind ion (replace H 2 O) • only right one fits
Channels O in selectivity filter bind ion (replace H 2 O) • only right one fits • driving force? electrochemical D
Channels driving force : electrochemical D “non-saturable”
Channels driving force : electrochemical D “non-saturable” regulate by opening & closing
Channels regulate by opening & closing ligand-gated channels open/close when bind specific chemicals
Channels ligand-gated channels open/close when bind specific chemicals Stress-activated channels open/close in response to mechanical stimulation
Channels Stress-activated channels open/close in response to mechanical stimulation voltage-gated channels open/close in response to changes in electrical potential
Channels • Old model: S 4 slides up/down • Paddle model: S 4 rotates
Channels • Old model: S 4 slides up/down • Paddle model: S 4 rotates • 3 states 1. Closed 2. Open 3. Inactivated
Selective Transport 1) Channels 2) Facilitated Diffusion (carriers) Carrier binds molecule
Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside
Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside driving force = ∆ [ ]
Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside driving force = ∆ [ ] Important for sugar transport
Selective Transport Facilitated Diffusion (carriers) Characteristics 1) saturable 2) specific 3) passive: transports down ∆ []
Selective Transport 1) Channels 2) Facilitated Diffusion (carriers) Passive transport should equalize [ ] Nothing in a plant cell is at equilibrium!
Selective Transport Passive transport should equalize [ ] Nothing in a plant cell is at equilibrium! Solution: use energy to transport specific ions against their ∆[]
Active Transport Integral membrane proteins • use energy to transport specific ions against their ∆ [ ] • allow cells to concentrate some chemicals, exclude others
Active Transport Characteristics 1) saturable 105 -106 ions/s 102 -104 molecules/s
Active Transport Characteristics 1) saturable 2) specific
Active Transport Characteristics 1) saturable 2) specific 3) active: transport up ∆ [ ] (or ∆ Em)
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) • Na/K pump • Ca pump in ER & PM • H+ pump in PM • pumps H+ out of cell
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V = “vacuole”) • H+ pump in vacuoles
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V=“vacuole”) 3) F-type ATPases (F = “factor”) a. k. a. ATP synthases • mitochondrial ATP synthase • chloroplast ATP synthase
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V = “vacuole”) 3) F-type ATPases (F = “factor”) 4) ABC ATPases (ABC = “ATP Binding Cassette”) • multidrug resistance proteins
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V = “vacuole”) 3) F-type ATPases (F = “factor”) 4) ABC ATPases (ABC = “ATP Binding Cassette”) • multidrug resistance proteins pump hydrophobic drugs out of cells very broad specificity
Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ]
Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ] Symport: both substances pumped same way
Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ] Symport: both substances pumped same way Antiport: substances pumped opposite ways
Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ] Symport: both substances pumped same way Antiport: substances pumped opposite ways
Rhizosphere Ectomycorrhizae surround root Endomycorrhizae invade root cells: Vesicular/Arbuscular Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere • Chemicals that harm rhizosphere microbes harm plants!
Rhizosphere Ectomycorrhizae surround root Endomycorrhizae invade root cells: Vesicular/Arbuscular Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere • Chemicals that harm rhizosphere microbes harm plants! • Root-microbe interactions help take up rhizosphere metals
Nutrient uptake Most nutrients are dissolved in water • Enter root through apoplast until hit endodermis • Then must cross plasma membrane
Crossing membranes A) Diffusion through bilayer B) Difusion through protein pore Selective C) Facilitated diffusion D) Active transport E) Bulk transport Active 1) Exocytosis 2) Endocytosis
4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V = “vacuole”) 3) F-type ATPases (F = “factor”) 4) ABC ATPases (ABC = “ATP Binding Cassette”) • multidrug resistance proteins
Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ] Symport: both substances pumped same way Antiport: substances pumped opposite ways
Nutrient uptake Gases enter/exit by diffusion down their ∆ [ ]
Nutrient uptake Gases enter/exit by diffusion down their ∆ [ ] Ions vary dramatically!
Nutrient uptake Ions vary dramatically! H+ is actively pumped out of cell by P-type H+ -ATPase
Nutrient uptake Ions vary dramatically H+ is actively pumped out of cell by P-type H+ -ATPase and into vacuole by V-type ATPase & PPase
Nutrient uptake H+ is actively pumped out of cell by P-type H+ -ATPase and into vacuole by V-type ATPase & PPase • Main way plants make membrane potential (∆Em)!
Nutrient uptake H+ is actively pumped out of cell by P-type H+ -ATPase and into vacuole by V-type ATPase & PPase • Main way plants make membrane potential (∆Em)! • Used for many kinds of transport!
Nutrient uptake Many ions are imported by multiple transporters with varying affinities
Nutrient uptake Many ions are imported by multiple transporters with varying affinities • K+ diffuses through channels down ∆Em: low affinity
Nutrient uptake Many ions are imported by multiple transporters with varying affinities • K+ diffuses through channels down ∆Em: low affinity • Also taken up by H+ symporters : high affinity
Nutrient uptake Many ions are imported by multiple transporters with varying affinities • K+ diffuses through channels down ∆Em: low affinity • Also taken up by H+ symporters : high affinity • Low affinity is cheaper but less effective
Nutrient uptake K+ diffuses through channels down ∆Em: low affinity Also taken up by H+ symporters : high affinity Low affinity is cheaper but less effective some channels also transport Na+
Nutrient uptake K+ diffuses through channels down ∆Em: low affinity Also taken up by H+ symporters : high affinity Low affinity is cheaper but less effective some channels also transport Na+ why Na+ slows K+ uptake?
Nutrient uptake K+ diffuses through channels down ∆Em: low affinity Also taken up by H+ symporters : high affinity Low affinity is cheaper but less effective some channels also transport Na+ why Na+ slows K+ uptake? Na+ is also expelled by H+ antiport
Nutrient uptake Ca 2+ is expelled by P-type ATPases in PM
Nutrient uptake Ca 2+ is expelled by P-type ATPases in PM pumped into vacuole & ER by H+ antiport & P-type
Nutrient uptake Ca 2+ is expelled by P-type ATPases in PM pumped into vacuole & ER by H+ antiport & P-type • enters cytosol via gated channels
Nutrient uptake PO 43 -, SO 42 -, Cl- & NO 3 enter by H+ symport
Nutrient uptake PO 43 -, SO 42 -, Cl- & NO 3 - enter by H+ symport • also have anion transporters of ABC type
Nutrient uptake PO 43 -, SO 42 -, Cl- & NO 3 - enter by H+ symport • also have anion transporters of ABC type • and anion channels
Nutrient uptake PO 43 -, SO 42 -, Cl- & NO 3 - enter by H+ symport • also have anion transporters of ABC type • and anion channels Plants take up N many ways
Nutrient uptake Plants take up N many ways: NO 3 - & NH 4+ are main forms
Nutrient uptake Plants take up N many other ways • NO 3 - also by channels • NH 3 by diffusion • NH 4+ by carriers
Nutrient uptake Plants take up N many other ways • NO 3 - by channels • NH 3 by diffusion • NH 4+ by carriers • NH 4+ by channels
Nutrient uptake Plants take up N many other ways • 3 families of H+ symporters take up amino acids
Nutrient uptake Plants take up N many other ways • 3 families of H+ symporters take up amino acids • Also have many peptide transporters • some take up di- & tripeptides by H+ symport
Nutrient uptake Plants take up N many other ways • 3 families of H+ symporters take up amino acids • Also have many peptide transporters • some take up di- & tripeptides by H+ symport • others take up tetra- & penta-peptides by H+ symport
Nutrient uptake Plants take up N many other ways • 3 families of H+ symporters take up amino acids • Also have many peptide transporters • some take up di- & tripeptides by H+ symport • others take up tetra- & penta-peptides by H+ symport Also have ABC transporters that import peptides
Nutrient uptake Plants take up N many other ways • 3 families of H+ symporters take up amino acids • Also have many peptide transporters • some take up di- & tripeptides by H+ symport • others take up tetra- & penta-peptides by H+ symport Also have ABC transporters that import peptides N is vital! NO 3 - & NH 4+ are main forms
Nutrient uptake Metals are taken up by ZIP proteins & by ABC transporters • same protein may import Fe, Zn & Mn!
Nutrient uptake Much is coupled to p. H gradient
Nutrient transport in roots Move from soil to endodermis in apoplast
Nutrient transport in roots Move from soil to endodermis in apoplast Move from endodermis to xylem in symplast
Nutrient transport in roots Move from endodermis to xylem in symplast Transported into xylem by H+ antiporters
Nutrient transport in roots Move from endodermis to xylem in symplast Transported into xylem by H+ antiporters, channels
Nutrient transport in roots Transported into xylem by H+ antiporters, channels, pumps
Nutrient transport in roots Transported into xylem by H+ antiporters, channels, pumps Lowers xylem water potential -> root pressure
Water Transport Passes water & nutrients to xylem Ys of xylem makes root pressure Causes guttation: pumping water into shoot
Transport to shoot Nutrients move up plant in xylem sap
Nutrient transport in leaves Xylem sap moves through apoplast Leaf cells take up what they want
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