Nutrient Uptake by Root and Leaf and Nutrient

Nutrient Uptake by Root and Leaf and Nutrient Distribution

Nutrient

Soil solution, soil particle, soil colloid

Nutrient Donnan Free Space Cation Exchange Capacity (CEC)






IN XYLEM H 2 O Tip (Ca( Leaf Xylem Next cell Plasmalemma Cytoplasm Tonoplast Vacuole Tonoplast Cytoplasm Plasmalemma Plasmodesmata (Symplastic Pathway) plasma Endodermis Cortex Epidermis Root hair Soil solution Soilparticle

Nutrient ION UPTAKE BY ROOT - Root Interception (Soil – root Surface) - Mass flow (Transpiration Stream) - Diffusion (Conc. Gradient) Factors affecting. 1 Ion diameter radius Li+ > Na+ > R+ > Ce+ Uptake rate

Nutrient. 2 Valency Uncharged mol : <Cat+ , An- < Cat 2+, An 2 -< Cat 3+<An 3 Uptake rate . 3 Metabolic activity Energy Active Uptake Respiration (O 2, Temp. , CHO- Light) . 4 Interaction Between Ion - Competition (same valency & ion size) - Competition K+ inhibit NH 4+ uptake Ca 2+ & Mn 2+ inhibit Mg 2+ uptake Ce- inhibit No 3 - )���� , ����

. 5 p. H (H+ , OH+ ) p. H : uptake K+ NH+ No 3 - . 6 Ion Synergism Ca 2+ K+ K+ uptake – low p. H uptake – high p. H . 7 Cation – Anion Relationship Electrical charge balancing . 8 External Concentration. 9 Internal Concentration & Nutrition Status. 10 Plant Development & Nutrifional Requirement

TRANSLOCATION OF ION IN XYLEM -Diffusion (Cation exchange, , valency, Organic compounel -Mass flow (Transpiration stream) -Resorption (Companion cell) Resorption (Accumulation, Phloem) Plant age Time of day (Morning, afternoon, Dark, Light) External Concentration Internal Concentration Uncharged Molecule > ions

TRANSLOCATION OF ION IN PHLOEM. 1 Components : - Sieve tube elements - Companion cells - Parenchyma cells Sieve Plate Pore (Plasmodesmata) Callose (Highly hydrated Polysaccharide) Swelling - heat treatment Blocking - mechanical injury of phloem

Nutrient. 2 Composition of phloem sap : (using aphid) exudate : p. H 7 -8 Solids 15 -25% drymatter Sucrose 90% Organic acid Organically bound N K>P > Mg > S > Ca (Micro. -rare) Cation > Anion (Amino acid for compensation)

Nutrient. 3 Mobility of mineral element in phloem Mobile K Ru Na Mg P S Cl Intermediate Immobile Fc Mn Zn Cu Mo Li Ca Str Ba B

Nutrient. 4 Direction of Phloem Transport Active Leaf Senescence Leaf (elements) Xylem : Unidirection Phloem : Bidirection (Source Sink) * * * - Root, Shoot apice, fruit, seed, Stressed tissue

Nutrient. 5 Mechanism of Translocation * - Sink – Source Relationship - Others - Retranslocation (Shoot root) (Toxic elements : Na+, Cl-) - Transfer between Xylem – Phloem (Active transport from xylem to phloem of elements) good for translocation to active sites

Nutrient. 6 Remobilization (except Ca, B) Seed germination, Insufficient supply, Interupted supply, Reproductive stage, Senescence Nutrient N, K, Mg, P S Fc, Zn, Cu, Mo B, Ca Symptom Old Leaves Young Leaves & apical meristem Remo. Very good Insuf. Very low nil

Nutrient ION RELEASE • Leaching • Guttation • Excretion • Senescence organ • Exchange (Ion Balance)

Nutrient MOBILITY Mobile K Na Mg P S Cl Rb Intermediate Immobile Fe Mn Zn Cu Mo Ca B Li Sr Ba

Nutrient ION UPTAKE BY LEAVES & OTHER AERIAL PARTS 1. Uptake of gases through stomata - CO 2, O 2 gas exchange - Mineral nutrient in form of gases : SO 2, NH 3, NOx - SO 2 uptake through stomata SO 42 - uptake through root - Competitive of SO 2 to CO 2 in C 3 – Pn pathway (Rub. P)

Nutrient 2. Uptake of Solute 2. 1 Uptake through stomata 2. 2 Structure & Function of Cuticular layer Structure : Cuticular layer = layer of wax & Cutin & Pectin, hemicellulose & Cellulose Cutin = a condensation product of C 18 hydroxy fatty acids with semihydrophilic properties Function : - Protect the excessive water loss - Protect against excessive leaching of solutes by rain

Nutrient 3. Factors affecting uptake rate 3. 1 External factors - Concentration, Valency, - Temperature - Environments (thickness of C. I. ) - shade, unshaded leaves - Light, temperature water evaporation from foliar spray 3. 2 Internal factors - Nutritional status of plant (deficient > well supplied) - Leaf age (old uptake ) - Metabolic activity - Sink activity - Membrane permeability - Thickness of cuticle

Nutrient 4. Foliar Application of Mineral Nutrients - more rapid than root application - more specific 4. 1 Problems: (1 Low penetration rate (esp. thick cuticle) (2 Run – off from hydrophobic surface (3 Washing off by rain (4 Rapid dry of spray solution (5 Limited rate of retranslocation (ex. Ca 2+) (6 Limited amounts (Concentration & leaf burn) aver. 1% except. Urea 10%

Nutrient 4. 2 When to apply through leaf - Low nutrient availability in soil (p. H, soil type, fixation, solubility) Dry topsoil Decrease in root activity during reproductive stage Increase in protein content of cereal seeds Increase in Ca content of plant parts (Fruit, tip) end
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