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

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