1. Mineral Nutrition Studied by soil-free culture in nutrient solutions:

2. Mineral Nutrition Macronutrients: CHOPKNSCaFeMg Ca: signaling, middle lamella, cofactor Fe: cofactor Mg: cofactor mobile in plant, so shows first in old leaves

3. Mineral Nutrition Micronutrients: BNaCl 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

4. Mineral Nutrition Commercial fertilizers mainly supply NPK

5. 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%)

6. Mineral Nutrition Soil nutrients Amounts & availability vary Many are immobile, eg P, Fe

7. Mineral Nutrition Soil nutrients Amounts & availability vary Many are immobile, eg P, Fe Mobile nutrients come with soil H 2 O

8. 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

9. Mineral Nutrition Immobile nutrients must be “mined” Root hairs get close Mycorrhizae get closer

10. Mineral Nutrition Immobile nutrients must be mined Root hairs get close Mycorrhizae get closer Solubility varies w pH

11. Mineral Nutrition Solubility varies w pH 5.5 is best compromise

12. Mineral Nutrition Solubility varies w pH 5.5 is best compromise Plants alter pH @ roots to aid uptake

13. Mineral Nutrition Nutrients in soil Plants alter pH @ roots to aid uptake Also use symbionts Mycorrhizal fungi help: especially with P

14. Mineral Nutrition Also use symbionts Mycorrhizal fungi help: especially with P P travels poorly: fungal hyphae are longer & thinner

15. Mineral Nutrition Also use symbionts Mycorrhizal fungi help: especially with P P travels poorly: fungal hyphae are longer & thinner Fungi give plants nutrients

16. 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

17. 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

18. Mineral Nutrition Ectomycorrhizae surround root: only trees, esp. conifers release nutrients into apoplast to be taken up by roots

19. 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

20. Mineral Nutrition Endomycorrhizae invade root cells: Vesicular/Arbuscular Most angiosperms, especially in nutrient-poor soils May deliver nutrients into symplast

21. 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

22. 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

23. Rhizosphere Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere Plants feed them lots of C!

24. Rhizosphere Also find bacteria, actinomycetes, protozoa associated with root surface = rhizosphere Plants feed them lots of C! They help make nutrients available

25. 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

26. Rhizosphere N-fixing bacteria supply N to many plant spp Most live in root nodules & are fed & protected from O 2 by plant

27. Nutrient uptake Most nutrients are dissolved in water

28. Nutrient uptake Most nutrients are dissolved in water Enter root through apoplast until hit endodermis

29. Nutrient uptake Most nutrients are dissolved in water Enter root through apoplast until hit endodermis Then must cross plasma membrane

30. Crossing membranes A) Diffusion through bilayer B) Difusion through protein pore C) Facilitated diffusion D) Active transport E) Bulk transport 1) Exocytosis 2) Endocytosis Selective Active

31. Nutrient uptake Then must cross plasma membrane Gases, small uncharged & non-polar molecules diffuse

32. Nutrient uptake Then must cross plasma membrane Gases, small uncharged & non-polar molecules diffuse down their ∆ [ ] Important for CO 2, auxin & NH 3 transport

33. Nutrient uptake Then must cross plasma membrane Gases, small uncharged & non-polar molecules diffuse down their ∆ [ ] Polar chems must go through proteins!

34. Selective Transport 1) Channels integral membrane proteins with pore that specific ions diffuse through

35. Selective Transport 1) Channels integral membrane proteins with pore that specific ions diffuse through depends on size & charge

36. Channels integral membrane proteins with pore that specific ions diffuse through depends on size & charge O in selectivity filter bind ion (replace H2O)

37. Channels integral membrane proteins with pore that specific ions diffuse through depends on size & charge O in selectivity filter bind ion (replace H2O) only right one fits

38. Channels O in selectivity filter bind ion (replace H2O) only right one fits driving force? electrochemical 

39. Channels driving force : electrochemical  “non-saturable”

40. Channels driving force : electrochemical  “non-saturable” regulate by opening & closing

41. Channels regulate by opening & closing ligand-gated channels open/close when bind specific chemicals

42. Channels ligand-gated channels open/close when bind specific chemicals Stress-activated channels open/close in response to mechanical stimulation

43. Channels Stress-activated channels open/close in response to mechanical stimulation voltage-gated channels open/close in response to changes in electrical potential

44. Channels Old model: S4 slides up/down Paddle model: S4 rotates

45. Channels Old model: S4 slides up/down Paddle model: S4 rotates 3 states 1.Closed 2.Open 3. Inactivated

46. Selective Transport 1) Channels 2) Facilitated Diffusion (carriers) Carrier binds molecule

47. Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside

48. Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside driving force = ∆ [ ]

49. Selective Transport Facilitated Diffusion (carriers) Carrier binds molecule carries it through membrane & releases it inside driving force = ∆ [ ] Important for sugar transport

50. Selective Transport Facilitated Diffusion (carriers) Characteristics 1) saturable 2) specific 3) passive: transports down ∆ []

51. Selective Transport 1) Channels 2) Facilitated Diffusion (carriers) Passive transport should equalize [ ] Nothing in a plant cell is at equilibrium!

52. Selective Transport Passive transport should equalize [ ] Nothing in a plant cell is at equilibrium! Solution: use energy to transport specific ions against their ∆ [ ]

53. Active Transport Integral membrane proteins use energy to transport specific ions against their ∆ [ ] allow cells to concentrate some chemicals, exclude others

54. Active Transport Characteristics 1) saturable 10 2 -10 4 molecules/s10 5 -10 6 ions/s

55. Active Transport Characteristics 1) saturable 2) specific

56. Active Transport Characteristics 1) saturable 2) specific 3) active: transport up ∆ [ ] (or ∆ Em)

57. 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

58. 4 classes of Active transport ATPase proteins 1) P-type ATPases (P = “phosphorylation”) 2) V-type ATPases (V = “vacuole”) H + pump in vacuoles

59. 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

60. 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

61. 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

62. Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ]

63. Secondary active transport Uses ∆ [ ] created by active transport to pump something else across a membrane against its ∆ [ ] Symport: both substances pumped same way

64. 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

65. 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

66. 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!

67. 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

68. Nutrient uptake Most nutrients are dissolved in water Enter root through apoplast until hit endodermis Then must cross plasma membrane

69. Crossing membranes A) Diffusion through bilayer B) Difusion through protein pore C) Facilitated diffusion D) Active transport E) Bulk transport 1) Exocytosis 2) Endocytosis Selective Active

70. 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

71. 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

72. Nutrient uptake Gases enter/exit by diffusion down their ∆ [ ]

73. Nutrient uptake Gases enter/exit by diffusion down their ∆ [ ] Ions vary dramatically!

74. Nutrient uptake Ions vary dramatically! H + is actively pumped out of cell by P-type H + -ATPase

75. 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

76. 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)!

77. 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!

78. Nutrient uptake Many ions are imported by multiple transporters with varying affinities

79. Nutrient uptake Many ions are imported by multiple transporters with varying affinities K + diffuses through channels down ∆Em: low affinity

80. 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

81. 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

82. 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 +

83. 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?

84. 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

85. Nutrient uptake Ca 2+ is expelled by P-type ATPases in PM

86. Nutrient uptake Ca 2+ is expelled by P-type ATPases in PM pumped into vacuole & ER by H + antiport & P-type

87. 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

88. Nutrient uptake PO 4 3-, SO 4 2-, Cl - & NO 3 - enter by H + symport

89. Nutrient uptake PO 4 3-, SO 4 2-, Cl - & NO 3 - enter by H + symport also have anion transporters of ABC type

90. Nutrient uptake PO 4 3-, SO 4 2-, Cl - & NO 3 - enter by H + symport also have anion transporters of ABC type and anion channels

91. Nutrient uptake PO 4 3-, SO 4 2-, Cl - & NO 3 - enter by H + symport also have anion transporters of ABC type and anion channels Plants take up N many ways

92. Nutrient uptake Plants take up N many ways: NO 3 - & NH 4 + are main forms

93. Nutrient uptake Plants take up N many other ways NO 3 - also by channels NH 3 by diffusion NH 4 + by carriers

94. 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

95. Nutrient uptake Plants take up N many other ways 3 families of H + symporters take up amino acids

96. 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- & tri- peptides by H + symport

97. 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- & tri- peptides by H + symport others take up tetra- & penta-peptides by H + symport

98. 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- & tri- peptides by H + symport others take up tetra- & penta-peptides by H + symport Also have ABC transporters that import peptides

99. 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- & tri- peptides 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

100. Nutrient uptake Metals are taken up by ZIP proteins & by ABC transporters same protein may import Fe, Zn & Mn!

101. Nutrient uptake Much is coupled to pH gradient

102. Nutrient transport in roots Move from soil to endodermis in apoplast

103. Nutrient transport in roots Move from soil to endodermis in apoplast Move from endodermis to xylem in symplast

104. Nutrient transport in roots Move from endodermis to xylem in symplast Transported into xylem by H + antiporters

105. Nutrient transport in roots Move from endodermis to xylem in symplast Transported into xylem by H + antiporters, channels

106. Nutrient transport in roots Transported into xylem by H + antiporters, channels,pumps

107. Nutrient transport in roots Transported into xylem by H + antiporters, channels,pumps Lowers xylem water potential -> root pressure

108. Water Transport Passes water & nutrients to xylem  s of xylem makes root pressure Causes guttation: pumping water into shoot

109. Transport to shoot Nutrients move up plant in xylem sap

110. Nutrient transport in leaves Xylem sap moves through apoplast Leaf cells take up what they want

111. Photosynthesis Converts light to chemical energy 6 CO 2 + 6 H 2 O + light energy C 6 H 12 O 6 + 6 O 2

112. Photosynthesis 2 sets of rxns in separate parts of chloroplast

113. Photosynthesis 1) Light rxns use light to pump H + use ∆ pH to make ATP by chemiosmosis

114. Photosynthesis 1) Light rxns use light to pump H + use ∆ pH to make ATP by chemiosmosis 2) Light-independent (dark) rxns use ATP & NADPH from light rxns to make organics

115. Photosynthesis 1) Light rxns use light to pump H + use ∆ pH to make ATP by chemiosmosis 2) Light-independent (dark) rxns use ATP & NADPH from light rxns to make organics only link: each provides substrates needed by the other

116. Important structural features of chloroplasts very large organelles: 5-10 µm long, 2-4 µm wide

117. Important structural features of chloroplasts 3 membranes 1) outer envelope permeable to molecules up to 10 kDa due to porins

118. Important structural features of chloroplasts 3 membranes 1) outer envelope 2) inner envelope impermeable: all import/export is via transporters

119. Important structural features of chloroplasts 1) outer envelope 2) inner envelope 3) thylakoids: Stromal membranes

120. Important structural features of chloroplasts 3) thylakoids: Stromal membranes a) grana: stacks of closely appressed membranes b) stromal lamellae: single thylakoids linking grana

121. Important structural features of chloroplasts All cp membranes have MGDG, DGDG & SL thylakoids only have MGDG, DGDG, SL & PG thylakoid lipids have many trienoic fatty acids most fluid membranes known

122. Important structural features of chloroplasts Stroma is pH 8.0 in light thylakoid lumen is < 5 Stroma is full of protein also contains DNA & genetic apparatus

123. Light Rxns 3 stages 1) Catching a photon (primary photoevent)

124. Light Rxns 3 stages 1) Catching a photon (primary photoevent) 2) ETS

125. Light Rxns 3 stages 1) Catching a photon (primary photoevent) 2) ETS 3) ATP synthesis by chemiosmosis

126. Catching photons photons: particles of energy that travel as waves Energy inversely proportional to wavelength ( ) visible light ranges from 400 -700 nm

127. Catching photons Photons: particles of energy that travel as waves caught by pigments: molecules that absorb light

128. Pigments Can only absorb certain photons

129. Pigments Can only absorb certain photons Photon has exact energy to push an e- to an outer orbital

130. Pigments Can only absorb certain photons Photon has exact energy to push an e- to an outer orbital from ground to excited state

131. Pigments Photon has exact energy to push an e- to an outer orbital from ground to excited state each pigment has an absorption spectrum: it can absorb

132. Pigments Chlorophyll a is most abundant pigment chlorophyll a looks green -> absorbs all but green Reflects green

133. Accessory Pigments absorb which chlorophyll a misses chlorophyll b is an important accessory pigment

134. Accessory Pigments absorb which chlorophyll a misses chlorophyll b is an important accessory pigment others include xanthophylls & carotenoids

135. Accessory Pigments action spectrum shows use of accessory pigments used for photosynthesis

136. Accessory Pigments action spectrum shows use of accessory pigments used for photosynthesis plants use entire visible spectrum absorbed by chlorophyll work best

137. Light Reactions 1) Primary photoevent: pigment absorbs a photon

138. Light Reactions 1) Primary photoevent: pigment absorbs a photon e - is excited -> moves to outer orbital

139. Light Reactions 4 fates for excited e-: 1) returns to ground state emitting heat & longer light = fluorescence

140. Light Reactions 4 fates for excited e - : 1) fluorescence 2) transfer to another molecule

141. Light Reactions 4 fates for excited e - : 1) fluorescence 2) transfer to another molecule 3) Returns to ground state dumping energy as heat

142. 4 fates for excited e - : 1) fluorescence 2) transfer to another molecule 3) Returns to ground state dumping energy as heat 4) energy is transferred by inductive resonance excited e - vibrates and induces adjacent e - to vibrate at same frequency

143. 4 fates for excited e - : 4) energy is transferred by inductive resonance excited e - vibrates and induces adjacent e - to vibrate at same frequency Only energy is transferred

144. 4 fates for excited e - : 4) energy is transferred by inductive resonance excited e - vibrates and induces adjacent e - to vibrate at same frequency Only energy is transferred e - returns to ground state