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Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower
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Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower Environmental influences on flowering
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Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower Environmental influences on flowering 2. Pick some plants to study
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Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower Environmental influences on flowering 2. Pick some plants to study 3. Get them growing
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Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower Environmental influences on flowering 2. Pick some plants to study 3. Get them growing 4. Design some experiments for other things to test before they start flowering
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants C3, C4, CAM
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants C3, C4, CAM Long Day, short day, Day neutral
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants C3, C4, CAM Long Day, short day, Day neutral Tropical, temperate, arctic
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants C3, C4, CAM Long Day, short day, Day neutral Tropical, temperate, arctic ?????
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Game plan Suggestions 1.Arabidopsis2. Fast plant 3. Sorghum4. Brachypodium distachyon 5. Amaranthus6. Quinoa 7. Kalanchoe8. Venus fly traps Options 1.Pick several plants C3, C4, CAM Long Day, short day, Day neutral Tropical, temperate, arctic ????? 2.Pick one plant Study many conditions
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Options 1.Pick several plants C3, C4, CAM Long Day, short day, Day neutral Tropical, temperate, arctic ????? 2.Pick one plant Study many conditions Study many variants/mutants ?????
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Grading? Combination of papers, presentations & lab reports 4 lab reports @ 2.5 points each 5 assignments @ 2 points each Presentation on global change and plants: 5 points Research proposal: 10 points Final presentation: 15 points Poster: 10 points Draft report 10 points Final report: 30 points Assignment 1 1.Pick a plant that might be worth studying Try to convince the group in 5-10 minutes why yours is best: i.e., what is known/what isn’t known
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Plant Growth & Development Occurs in 3 stages 1.Embryogenesis From fertilization to seed 2. Vegetative growth Juvenile stage From seed germination to adult "phase change" marks transition 3. Reproductive development Start making flowers, can reproduce sexually
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Transition to Adult Phase Juveniles & adults are very different!
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Transition to Flowering Adults are competent to flower, but need correct signals Very complex process! Can be affected by: Daylength Temperature (especially cold!) Water stress Nutrition Hormones
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Early Studies Julius Sachs (1865) first proposed florigen Garner and Allard (1920) discovered photoperiodism Maryland Mammoth tobacco flowers in the S but not in N Knott (1934) day length is perceived by the leaves
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Early Studies Knott (1934) day length is perceived by the leaves Flowers are formed at SAM! Florigen moves from leaves to SAM Is graft-transmissable! Moves in phloem
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Complications Some plants are qualitative (must have correct daylength), others are quantitative (correct days speed flowering) Four pathways control flowering: 1.Photoperiod PHY only PHY + CRY 2.Vernalization: requires cold period 3.gibberellin (GA) 4.Autonomous
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Complications Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time
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Genes controlling flowering Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time 1.CONSTANS (CO): co mutants are day-length insensitive & flower late
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Genes controlling flowering Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time 1.CONSTANS (CO): co mutants are day-length insensitive & flower late CO mRNA is expressed in leaf but not SAM & increases in LD
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Genes controlling flowering Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time 1.CONSTANS (CO): co mutants are day-length insensitive & flower late CO mRNA is expressed in leaf but not SAM & increases in LD CO encodes a ZN-finger transcription factor (TF) that induces expression of FLOWERING LOCUS T (FT)
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Genes controlling flowering Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time 1.CONSTANS (CO): co mutants are day-length insensitive & flower late CO mRNA is expressed in leaf but not SAM & increases in LD CO encodes a ZN-finger TF that induces expression of FLOWERING LOCUS T (FT) 2.FLOWERING LOCUS T (FT): a strong promoter of flowering
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Genes controlling flowering Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts Solved by identifying genes that control flowering time 1.CONSTANS (CO): co mutants are day-length insensitive & flower late CO mRNA is expressed in leaf but not SAM & increases in LD CO encodes a ZN-finger TF that induces expression of FLOWERING LOCUS T (FT) 2.FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein
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Genes controlling flowering 1.CONSTANS (CO): co mutants are day-length insensitive & flower late 2.FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein 3. FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses floweringMADS-box
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Genes controlling flowering 1.CONSTANS (CO): co mutants are day-length insensitive & flower late 2.FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein 3. FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses floweringMADS-box Highly expressed in non-vernalized tissues
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Genes controlling flowering 1.CONSTANS (CO): co mutants are day-length insensitive & flower late 2.FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein 3. FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses floweringMADS-box Highly expressed in non-vernalized tissues Turned off by vernalization due to chromatin mod
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Genes controlling flowering 1.CONSTANS (CO): co mutants are day-length insensitive & flower late 2.FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein 3. FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses floweringMADS-box Highly expressed in non-vernalized tissues Turned off by vernalization due to chromatin mod 4.SUPPRESSOR OF CONSTANS 1 (SOC1): a MADS- BOX TF that activates genes for floral development.
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Transition to flowering Upon induction, CO activates transcription of FT in leaves FT protein moves from leaves to shoot apex in phloem!
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Transition to flowering Upon induction, CO activates transcription of FT in leaves FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 & AP1
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Transition to flowering Upon induction, CO activates transcription of FT FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 &AP1 These activate LFY & Flower genes
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Transition to flowering Upon induction, CO activates transcription of FT FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 &AP1 These activate LFY & Flower genes Other signals converge On SOC1, either Directly or via FLC
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SDP Rice homolog to CO is Hd1 Inhibits expression of Hd3a (the FT homolog)
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SDP Rice homolog to CO is Hd1 Inhibits expression of Hd3a (the FT homolog) Induced by long days
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SDP Rice homolog to CO is Hd1 Inhibits expression of Hd3a (the FT homolog) Induced by long days Only make Hd3a protein under short days
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Transition to flowering Eventually start flowering Are now adults! Time needed varies from days to years. Shoot apical meristem now starts making new organ: flowers, with many new structures & cell types
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WATER Plants' most important chemical most often limits productivity
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WATER Plants' most important chemical most often limits productivity Often >90% of a plant cell’s weight
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WATER Plants' most important chemical most often limits productivity Often >90% of a plant cell’s weight Gives cells shape
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WATER Plants' most important chemical most often limits productivity Often >90% of a plant cell’s weight Gives cells shape Dissolves many chem
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WATER Dissolves many chem most biochem occurs in water Source of e - for PS
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WATER most biochem occurs in water Source of e - for PS Constantly lose water due to PS (1000 H 2 O/CO 2 )
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WATER most biochem occurs in water Source of e - for PS Constantly lose water due to PS Water transport is crucial!
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WATER Water transport is crucial! SPAC= Soil Plant Air Continuum moves from soil->plant->air
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WATER Formula = H 2 O Formula weight = 18 daltons Structure = tetrahedron, bond angle 104.5˚
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WATER Structure = tetrahedron, bond angle 104.5˚ polar :O is more attractive to electrons than H + on H - on O
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Water Polarity is reason for water’s properties water forms H-bonds with polar molecules
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Water Polarity is reason for water’s properties water forms H-bonds with polar molecules Hydrophilic = polar molecules Hydrophobic = non-polar molecules
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Properties of water 1)Cohesion = water H-bonded to water -> reason for surface tension
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Properties of water 1)Cohesion = water H-bonded to water -> reason for surface tension -> why water can be drawn from roots to leaves
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else Cohesion and adhesion are crucial for water movement in plants!
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else Cohesion and adhesion are crucial for water movement in plants! Surface tension & adhesion in mesophyll creates force that draws water through the plant!
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat absorb heat when break H-bonds: cools leaves
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat absorb heat when break H-bonds Release heat when form H-bonds
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat 4) Ice floats
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat 4) Ice floats 5) Universal solvent
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat 4) Ice floats 5) Universal solvent Take up & transport nutrients dissolved in water
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Properties of water 5) “Universal” solvent Take up & transport nutrients dissolved in water Transport organics dissolved in water
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat 4) Ice floats 5) Universal solvent 6) Hydrophobic bonds
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Properties of water 1) Cohesion = water H-bonded to water 2) Adhesion = water H-bonded to something else 3) high specific heat 4) Ice floats 5) Universal solvent 6) Hydrophobic bonds 7) Water ionizes
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pH [H + ] = acidity of a solution pH = convenient way to measure acidity pH = - log 10 [H + ] pH 7 is neutral: [H+] = [OH-] -> at pH 7 [H+] = 10 -7 moles/l
![pH [H + ] = acidity of a solution pH = convenient way to measure acidity pH = - log 10 [H + ] pH 7 is neutral: [H+] = [OH-] -> at pH 7 [H+] = moles/l](http://images.slideplayer.com/25/7857834/slides/slide_63.jpg "pH [H + ] = acidity of a solution pH = convenient way to measure acidity pH = - log 10 [H + ] pH 7 is neutral: [H+] = [OH-] -> at pH 7 [H+] = moles/l")
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pH Plants vary pH to control many processes!
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Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force?
![Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force](http://images.slideplayer.com/25/7857834/slides/slide_65.jpg "Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force")
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Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force: lowers free energy ∆G = ∆H- T∆S
![Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force: lowers free energy ∆G = ∆H- T∆S](http://images.slideplayer.com/25/7857834/slides/slide_66.jpg "Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Driving force: lowers free energy ∆G = ∆H- T∆S")
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Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient
![Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient](http://images.slideplayer.com/25/7857834/slides/slide_67.jpg "Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient")
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Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] !
![Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] !](http://images.slideplayer.com/25/7857834/slides/slide_68.jpg "Water movement Diffusion: movement of single molecules down ∆[ ] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] !")
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Water movement Diffusion: movement of single molecules down ∆[] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆[ ] ! How water moves through xylem
![Water movement Diffusion: movement of single molecules down ∆[] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆[ ] .](http://images.slideplayer.com/25/7857834/slides/slide_69.jpg "How water moves through xylem.")
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Water movement Diffusion: movement of single molecules down [] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] ! How water moves through xylem How water moves through soil and apoplast
![Water movement Diffusion: movement of single molecules down [] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] .](http://images.slideplayer.com/25/7857834/slides/slide_70.jpg "How water moves through xylem How water moves through soil and apoplast.")
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Water movement Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] ! How water moves through xylem Main way water moves through soil and apoplast Very sensitive to radius of vessel: increases as r 4
![Water movement Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆ [ ] .](http://images.slideplayer.com/25/7857834/slides/slide_71.jpg "How water moves through xylem Main way water moves through soil and apoplast Very sensitive to radius of vessel: increases as r 4.")
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Water movement Diffusion: movement of single molecules down ∆[] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆[ ] ! How water moves through xylem Main way water moves through soil and apoplast Very sensitive to radius of vessel: increases as r 4 Osmosis: depends on bulk flow and diffusion!
![Water movement Diffusion: movement of single molecules down ∆[] due to random motion until [ ] is even Bulk Flow: movement of groups of molecules down a pressure gradient Independent of ∆[ ] .](http://images.slideplayer.com/25/7857834/slides/slide_72.jpg "How water moves through xylem Main way water moves through soil and apoplast Very sensitive to radius of vessel: increases as r 4 Osmosis: depends on bulk flow and diffusion!.")
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Water movement Osmosis: depends on bulk flow and diffusion! water crosses membranes but other solutes do not water tries to even its [ ] on each side
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Water movement Osmosis: depends on bulk flow and diffusion! water crosses membranes but other solutes do not water tries to even its [ ] on each side other solutes can’t: result is net influx of water
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Water movement Osmosis: depends on bulk flow and diffusion! Moves through aquaporins, so rate depends on pressure and [ ] gradients!
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Water movement Osmosis: depends on bulk flow and diffusion! Moves through aquaporins, so rate depends on pressure and [ ] gradients! Driving force = water's free energy (J/m 3 = MPa)
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Water potential Driving force = water's free energy = water potential w Important for many aspects of plant physiology
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Water potential Driving force = water's free energy = water potential w Water moves to lower its potential
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Water potential Driving force = water's free energy = water potential w Water moves to lower its potential
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Water potential Driving force = water's free energy = water potential w Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential)
![Water potential Driving force = water s free energy = water potential w Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential)](http://images.slideplayer.com/25/7857834/slides/slide_80.jpg "Water potential Driving force = water s free energy = water potential w Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential)")
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Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells
![Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells](http://images.slideplayer.com/25/7857834/slides/slide_81.jpg "Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells")
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Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells Negative pressure in xylem!
![Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells Negative pressure in xylem!](http://images.slideplayer.com/25/7857834/slides/slide_82.jpg "Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure : p Turgor pressure inside cells Negative pressure in xylem!")
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Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g
![Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g](http://images.slideplayer.com/25/7857834/slides/slide_83.jpg "Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g")
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Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g w of pure water at sea level & 1 atm = 0 MPA
![Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g w of pure water at sea level & 1 atm = 0 MPA](http://images.slideplayer.com/25/7857834/slides/slide_84.jpg "Water potential Water moves to lower its potential Depends on: 1.[H 2 O]: s (osmotic potential) 2.Pressure p 3.Gravity g w = s + p + g w of pure water at sea level & 1 atm = 0 MPA")
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Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative
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Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in
![Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in](http://images.slideplayer.com/25/7857834/slides/slide_86.jpg "Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in")
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Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative
![Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative](http://images.slideplayer.com/25/7857834/slides/slide_87.jpg "Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative")
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Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative Usually positive in cells to counteract s
![Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative Usually positive in cells to counteract s](http://images.slideplayer.com/25/7857834/slides/slide_88.jpg "Water potential w = s + p + g w of pure water at sea level & 1 atm = 0 MPA s (osmotic potential) is always negative If increase [solutes] water will move in p (pressure potential) can be positive or negative Usually positive in cells to counteract s")
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Water potential p (pressure potential) can be positive or negative Usually positive in cells to counteract s Helps plants stay same size despite daily fluctuations in w
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Water potential w = s + p + g p (pressure potential) can be positive or negative Usually positive in cells to counteract s Helps plants stay same size despite daily fluctuations in w p in xylem is negative, draws water upwards
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Water potential w = s + p + g p (pressure potential) can be positive or negative Usually positive in cells to counteract s Helps plants stay same size despite daily fluctuations in w p in xylem is negative, draws water upwards g can usually be ignored, but important for tall trees
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