Administration of Reserves Alison Smith as25cam.ac.uk .


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Management of Reserves Alison Smith (as25@cam.ac.uk). CO 2 fixation produces triose P conversion to sucrose for translocation to sink tissues nutrient assimilation - N, S, P – and synthesis of all cellular components synthesis of reserves and their mobilisation regulation is essential.
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Administration of Reserves Alison Smith (as25@cam.ac.uk) CO 2 obsession produces triose P transformation to sucrose for translocation to sink tissues supplement digestion - N, S, P – and amalgamation of every single cell segment union of stores and their preparation control is vital

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Management of Reserves Lectures 9. Sugar blend, transport and capacity 10. Lipid amalgamation, preparation of stores 11. Direction of digestion system

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Lecture 9 - Carbohydrate Synthesis, Transport and Storage Sugars created by plant Pathway of sugar combination from photosynthate How would you work out what\'s occurring?!

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CO 2 PGA RuBP 1,3 bisPGA starch Triose P sucrose Synthesis of Starch and Sucrose Photosynthetic cell Sucrose is primary photosynthetic item represents a large portion of CO 2 assimilated vital capacity sugar tap base of carrots and sugar beet (up to 20% dry weight) and in leaves, eg 25% leaf dry weight in ivy real shape for translocation of carbon from photosynthetic leaves (source leaves) in developing seedlings after starch or lipid breakdown chloroplast RuBP = ribulose 1,5-bis-phosphate (pentose) 3-PGA = 3-phosphoglycerate 1,3 bisPGA = 1,3 bis-phosphoglycerate

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Sugar Translocation is Essential Sugars required for digestion system constantly, in all tissues Sugars created just by source tissues in light period Translocation happens source to sink over transient from capacity tissues to youthful tissues over long haul

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- separated aphid stylets best! stylet package cut by laser or radiofrequency microcautery Sugar alcohols (Polyols) CH 2 OH CH 2 OH | | HCOH HOCH | | HOCH HOCH | | HCOH HCOH | | HCOH HCOH | | CH 2 OH CH 2 OH Sorbitol (Rosaceae) Mannitol (Combretaceae ) Sugar translocation Analysis of phloem sap shallow cut delivers little sap Sugars Sucrose glucose-fructose (G-F) Raffinose G-G-F Stachyose Galactose-G-G-F

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Sugar organization of phloem sap > 500 unique species (100 families) of dicots (Zimmermann & Ziegler, 1975) Sucrose Raffinose Stachyose Sugar alcohols Most families ++++ + + - Aceraceae (maple) ++++ Tr - Anacardiaceae (cashew) +++ Tr - Asteraceae (aster) + Tr - Betulaceae (birch) ++++ ++ - Buddleiaceae (butterfly bush) ++ +++ ++++ - Caprifoliaceae (honeysuckle) +++ ++ Tr - Combretaceae (white mangrove) +++ ++ + +++ Fabaceae (legume) ++++ Tr - Fagaceae (beech & oak) ++++ Tr - Moraceae (fig) ++++ + ++ - Oleaceae (olive) ++ ++ +++ - Rosaceae (rose) +++ Tr ++++ Verbenaceae (verbena) ++ + ++++ - most families transport sucrose fixation in phloem sap can achieve 1 M

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starch Triose P sucrose chloroplast sucrose Non-photosynthetic cell long haul starch stockpiling roots, tubers, seeds starch amyloplast Starch is made in photosynthetic and non-photosynthetic cells Photosynthetic cell short lived starch stockpiling green leaves

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Importance of Starch is the predominant stockpiling polysaccharide in many plants In leaves - momentary starch - in chloroplasts high rate of CO 2 acclimatized goes straightforwardly into starch Sunflower after 47 min photosynthesis Carbon assimilated (mg) 7.87 Hexose accumulated 1.17 Sucrose 4.20 Starch 1.84 In nonphotosynthetic cells - capacity starch in amyloplasts stockpiling organs bananas, tubers (up to 80% dry weight), oat grains (75% dry weight) herbaceous roots, underground stems, globules perennials trees youthful twigs, roots, parenchyma of bark xylem & phloem

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acceptors for expansion of further glucose units polymer of glucose units begin (decreasing end) potato: oval, 100 µm in measurement rice: precise, 10 µm in distance across Composition of Starch Amylopectin  - 1,4 &  - 1,6-glucan 10,000 - 100,000 glucose units exceedingly stretched, 20 - 25 glucoses/branch Amylose  - 1,4-glucan ~1000 glucose units Starch grain Water insoluble, estimate & shape is species particular

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Leaves of calm Gramineae C3 grasses - grain, oats, rye grass major feedstuff for steers & sheep in mild zones Fructans Most normal are the fructans water-solvent, non lessening polymers of fructose 5 - 300 fructose units, joined to one glucose Some plants store different mixes Leaves, blooms and underground stockpiling organs Asteraceae (dahlias, jerusalem artichokes) Liliaceae (onions, asparagus) Iridaceae (irises) But store starch in the seed

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How are Sucrose and Starch Synthesized? Clarified via cautious biochemical studies Determination of compound exercises what responses are catalyzed, thermodynamic contemplations Correlation with flux through pathways is the movement which can be measured adequate to represent the procedure occurring?

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Fructose 6P UDP-Glucose Sucrose P Synthase UDP Sucrose P Sucrose P Phosphatase Pi Invertase Fructose + Glucose Sucrose Synthase UDP Fructose + UDP-Glucose Enzymes of Sucrose Metabolism Sucrose

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Sucrose is made by means of Sucrose-P Relationship between compound exercises and sucrose combination Activity (µmol/hr per g FW) Tissue Sucrose P Sucrose synthase synthase Spinacia oleracea leaf 25.0 0.4 Lolium temulentum leaf 9.6 0.4 Pisum sativum root stele 4.6 26.4 Pisum sativum root cortex 1.6 5.2 14 CO 2 joining tests demonstrate mark goes from UDP-Glucose  sucrose-P  sucrose

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Spin at 2000 g 2000 g pellet 2000 g supernatant Spin at 36000 g 36000 g pellet 36000 g supernatant Location of sucrose blend Homogenize tissue in isotonic cushion Subcellular fractionation of pea leaves Activity per part (µmol/h) Cell portion SPS Rubisco 2000 g pellet 0.74 273 36000 g pellet 2.6 74 Supernatant 19.3 350 ie SPS is in the cytosol

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3 PGA hexose P nmol/mg chl 125 time (sec) 100 75 50 25 0 10 20 30 40 Permeability of Chloroplast Envelope How does settled carbon get to the cytosol? Take-up of named mixes into separated chloroplasts CH 2 OP CH 2 OP CH 2 OP | | | CHOH C=O CHOH | | | COOH CH 2 OH CHO 3-P glycerate DHAP Glyceraldehyde 3-P Triose phosphate and 3-Pglycerate can cross envelope at rates practically identical to photosynthesis

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150 100 nmol/mg chl 50 Pi discharged 3-PGA taken up 0 100 200 300 400 time (sec) Phosphate Translocator Competition tests take-up of 3-carbon mixes by same transporter strict counter trade for Pi Export of carbon Major compound sent out is DHAP – 20X more than Ga3P

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UTP PPi CH 2 OH O OH O-P-O-P-O-uridine OH O - O - O Synthesis of UDP-Glucose Triose P is changed over to hexose P by gluconeogenesis This must be changed over to substrate for sucrose P synthase (UDP-G) Glucose 1-P UDP-G pyrophosphorylase

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Ga3P DHAP FBP Pi F6P G6P sucrose P sucrose G1P UTP PPi UDGP Pathway of sucrose combination from CO 2 CO 2 RuBP DHAP CO 2 3PGA Ga3P 1,3 bisPGA

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ADPglucose  1,4 glucan n ADPG PPiase Starch synthase ATP Glucose 1-P PPi  1,4 glucan n Glucose 1-P Pi Starch phosphorylase Enzymes of Starch Synthesis  1,4 glucan n+1 Starch

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starch synthase ADP-G ADP Starch Synthesis in vivo Hard to gauge starch synthase and phosphorylase in vivo Phosphorylases act in degradative heading Arabidopsis starchless mutant Glucose units added to non-lessening end, from ADP-G, framing a - 1,4 connections Plants ADPG PPiase Starch Wild type 54 ± 5 7.3 ± 0.4 Mutant 0 0 F 1 (WT x Mutant) 50 ± 4 6.0 ± 0.5

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round versus wrinkled peas The First Plant Biochemist Gregor Mendel 1822-1888

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" Branching Enzyme\' Activity in developing lives Weight (mg) BE (µmol.min - 1 ) Starch (mg) rr 100 0.89 0 4 0.8 200 2.98 0 20 2.2 300 3.95 0.56 60 5.4 400 7.81 1.12 86 16.5 Mendel\'s Wrinkled Peas wrinkled (rr) peas have less amylopectin than wt - crumple on drying One isozyme of BE has 0.8 kbp transposon in r locus ( rugosus) [Alison Smith, John Innes Centre]

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begin starch synthase begin a - 1,4 connection expanding chemical a - 1,6 connection Branching Enzyme Branching catalyst shapes the  - 1,6 connections

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source cell CO 2 PGA RuBP 1,3 bisPGA starch Triose P sucrose fare to phloem chloroplast Synthesis of Transitory Starch ADP-G PPiase, Starch synthase and BE all found in chloroplast

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Lecture 9 - Summary Sugars translocated Mainly sucrose, additionally other tri-and tetrasaccharides and sugar alcohols Storage sugar starch or fructans Elucidating a metabolic pathway deciding protein exercises, corresponding with flux estimations Subcellular area cell fractionati

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