nutrient uptake

Information about nutrient uptake

Published on July 15, 2014

Author: nagreddy33



PowerPoint Presentation: WEL COME PowerPoint Presentation: Credit Seminar on Various mechanisms in uptake of nutrients in horticulture crops P. NAGIREDDY RHD/2013-03 Dept. of Fruit Science PowerPoint Presentation: Why mineral nutrients are needed? In most natural soils, the availability of mineral nutrients limits plant growth and primary productivity. Nutrient limitation is an important selective pressure and plants exhibit many special traits related to the need to acquire and use mineral nutrients efficiently. PowerPoint Presentation: For the growth & metabolism and for completion of life cycle, organism including plant require various substances and are obtained from the environment surrounding them is called “ Nutrition ”. Such substances needed for the growth and survival of organisms/animals/plants are called the “ Nutrients ”. Not all elements seen in the periodic table are required. Only some are required. “ Mineral elements ” - An inorganic element Acquired mostly in the form of inorganic ions from the soil by the process of mining/uptake. PowerPoint Presentation: Name Chemical Relative Function in plant symbol % in plant Primary macronutrients Nitrogen N 10 Proteins, amino acids Phosphorus P 6 Nucleic acids, ATP Potassium K 25 Catalyst, ion transport Secondary macronutrients Calcium Ca 12.5 Cell wall component Magnesium Mg 8 Part of chlorophyll Sulfur S 3 Amino acids Iron Fe 0.2 Chlorophyll synthesis Micronutrients Copper Cu 0.01 Component of enzymes Manganese Mn 0.1 Activates enzymes Zinc Zn 0.03 Activates enzymes Boron B 0.2 Cell wall component Molybdenum Mo 0.0001 Involved in N fixation Chlorine Cl 0.3 Photosynthesis reactions PowerPoint Presentation: How do nutrients get to roots Roots absorb only dissolved nutrients in direct contact with live cells Roots comprise <1% of the belowground volume Nutrients have to move from bulk soil to root surface 1. Diffusion (most important for limiting macronutrients) 2. Mass flow (most imp. for macronutrients in high concentrations, & for micronutrients) 3. Root interception Ways Nutrients Reach Plants Roots: Mass Flow Movement of ions through soil solution (water) Long distance transport Diffusion Movement of ions from high concentration to low concentration Short distances Root Interception Root moves to the nutrient Ways Nutrients Reach Plants Roots Mobility and Uptake Mechanisms: Mass Flow - Mobile nutrients Diffusion - Immobile and mobile nutrients Root Interception - Immobile nutrients Mobility and Uptake Mechanisms Nutrient Supply Mechanism, % Interception Mass Flow Diffusion Nitrogen 1 99 0 Phosphorus 2 5 93 Potassium 2 20 78 PowerPoint Presentation: * Where the number exceeds 100%, the nutrient has the potential of being over-supplied to the vine through this method. Pieter Raath (2006) GRAPE PowerPoint Presentation: Movement of nutrients to the root surface PowerPoint Presentation: Factors affecting nutrient uptake Intrinsic factors Ion diameter Valency Environmental factors Light Temperature Water O 2 p H Concentration Interactions between nutrients PowerPoint Presentation: Water Except Interception, nutrients are transferring through Mass-flow and diffusion, all of which are dissolved in soil solution. It is important to maintain a suitable soil water content (60-80% field water holding capacity ) for optimal growing of upland plants . Interaction between ions Competition (Antagonism): one ion inhibits the absorption of another ion Synergism: one ion enhances the absorption of another ion. PowerPoint Presentation: Hormoz bassirirad (2000) A conceptual diagram depicting the way in which kinetics of root nutrient uptake The soil pH affects nutrient absorption: The soil pH affects nutrient absorption pH affects the growth of plant roots and soil microbes Root growth favors a pH of 5.5 to 6.5 Acidic conditions weathers rock and releases potassium , magnesium , calcium , and manganese . The decomposition of organic material lowers soil pH. Rainfall leaches ions through soil to form alkaline conditions PowerPoint Presentation: Water holding capacity of soil in turn influences nutrient availability PowerPoint Presentation: Increasing bulk density of soil (i.e., compaction) decreases crop uptake of soil P. Soil Texture Bulk Density (g/cm 3 ) P Uptake (mg/pot) Loamy Sand 1.30 1.60 1.90 63.7 47.5 12.2 Silty Clay 1.10 1.35 1.50 78.1 48.4 29.6 Rigas E . The soil affects nutrient absorption: The soil affects nutrient absorption Negatively charged soil particles affect the absorption of mineral nutrients Cation exchange occurs on the surface of the soil particle Cations (+ ve charged ions) bind to soil as it is – ve charded If potassium binds to the soil it can displace calcium from the soil particle and make it available for uptake by the root Plants Develop Extensive Root Systems: Plants Develop Extensive Root Systems The capability of the root to exploit the soil for nutrients depends largely on the root depth, root branching as well as the number of root hairs and root tips , i.e. the volume of soil utilised by the roots and their rate of proliferation. E xample , nutrients like Ca 2+, Mg 2+ and Fe 2+ are mainly absorbed by young roots The ability to utilise these nutrients strongly depends on the number of active root tips present in the soil Plant roots – the primary route for mineral nutrient acquisition: Meristematic zone Cells divide both in direction of root base to form cells that will become the functional root and in the direction of the root apex to form the root cap Elongation zone Cells elongate rapidly, undergo final round of divisions to form the endodermis . Some cells thicken to form casparian strip Maturation zone Fully formed root with xylem and phloem – root hairs first appear here Plant roots – the primary route for mineral nutrient acquisition Root absorbs different mineral ions in different areas: Root absorbs different mineral ions in different areas Calcium Apical region Iron Apical region (barley) or entire root (corn) Nitrate, Ammonium, Phosphate and Potassium, All locations of root surface In corn, elongation zone has max K accumulation and nitrate absorption In corn and rice, root apex absorbs ammonium faster than the elongation zone does In several species, root hairs are the most active phosphate absorbers Root uptake soon depletes nutrients near the roots: Root uptake soon depletes nutrients near the roots In the soil near the plant root a “ nutrient depletion zone ” Forms when rate of nutrient uptake exceeds rate of replacement in soil by diffusion in the water column Root associations with Mycorrhizal fungi help the plant overcome this problem Mycorrhizal associations: Mycorrhizal associations 83% of dicots, 79% of monocots and all gymnosperms Ectotrophic Mycorrhizal fungi Form a thick sheath around root. Some mycelium penetrates the cortex cells of the root Root cortex cells are not penetrated, surrounded by a zone of hyphae called Hartig net The capacity of the root system to absorb nutrients improved by this association – the fungal hyphae are finer than root hairs and can reach beyond nutrient-depleted zones in the soil near the root Mycorrhizal associations: Vesicular Arbuscular mycorrhiza Hyphae grow in dense arrangement , both within the root itself and extending out from the root into the soil After entering root, either by root hair or through epidermis hyphae move through regions between cells and penetrate individual cortex cells. Within cells form oval structures – vesicles – and branched structures – arbuscules ( site of nutrient transfer) P, Cu, & Zn absorption improved by hyphae reaching beyond the nutrient-depleted zones in the soil near the root Mycorrhizal associatio ns Nutrients move from fungi to root cells: Nutrients move from fungi to root cells In Ectotrophic Mycorrhiza Occurs by simple diffusion from the hyphae in the hartignet to the root cells I n Vesicular Arbuscular Mycorrhiza Occurs by simple diffusion from the arbuscules to the root cells Also, as arbuscules are degenerating as new ones are forming, the nutrients may be released directly into the host cell PowerPoint Presentation: Types of Membrane Transport Mechanisms PowerPoint Presentation: Ion exchange Contact exchange theory 1. Passive absorption PowerPoint Presentation: Carbonic acid exchange theory PowerPoint Presentation: Cations enter root hairs via channels or carriers PowerPoint Presentation: Anions enter root hairs via co transporters PowerPoint Presentation: ATP ase proton pump Sivakumar Swamy G PowerPoint Presentation: Calcium uptake as plotted against water uptake (convective Ca uptake as predicted from water uptake and Ca concentration in the inlet solution) (adapted from Rufyikiri et al . 2001). PowerPoint Presentation: Potassium uptake as plotted against water uptake (convective K uptake as predicted from water uptake and K concentration in the inlet solution) (adapted from Rufyikiri et al . 2001). PowerPoint Presentation: Relationship between net H+/OH- release by banana roots and cation -anion balance of uptake (adapted from Rufyikiri et al . 2001). PowerPoint Presentation: Week variation of the Mg and Al contents of banana roots growing in the close vicinity of smectite and kaolinite clay minerals (adapted from Rufyikiri et al . 2004). PowerPoint Presentation: Cu-extractable contents of Al, Mg, Ca of banana root exchange sites from bananas cultivated in controlled conditions (continuous flow device) as well as in field conditions (Andosol, Acrisol ) (adapted from Rufyikiri et al . 2002, 2003). PowerPoint Presentation: Effect of AMF and PGPR inoculation on dry weights of shoot, root, fruits and Zn uptake of lady’s finger Treatment Shoot dry weight (g plant-1) Root dry weight (g plant-1) Fruit (g plant-1) Zn uptake (Fruit plant -1 ) Control 47.55 b* 8.28 b 1.88 b 1.51 b AMF 53.72 ab 12.66 a 4.27 ab 3.20 ab UPMB10 53.33 ab 9.02 b 2.76 b 1.94 b AMF + UPMB10 61.86 a 13.08 a 6.75 a 4.96 a Naher et al . (2013) PowerPoint Presentation: Effect of AM and PGPR inoculation on growth of pineapple Treatments Dry weight (g plant -1 ) Number of leaves plant -1 Leaf length (cm) Control 2.08 19 16.15 AM 4.12 22 19.05 PGPR 4.95 20 22.0 AM + PGPR 5 20 17.02 Naher et al . (2013) PowerPoint Presentation: Mycorrhizal inoculation K Ca Mg Fe Cu Mn Leaf Root Leaf Root Leaf Root Leaf Root Leaf Root Leaf Root Nutrient concentration G. mosseae 32.16a 10.76a 3.51b 1.37b 2.88a 4.16a 2.13a 3.63a 0.03d 0.97a 0.17c 0.23a G. versiforme 29.50b 10.08b 5.38a 1.46b 2.49b 3.02b 1.72b 3.00b 0.12b 0.64c 0.29c 0.16b Paraglomus occultum 27.31c 9.06b 2.27c 1.72a 2.68b 3.84a 1.59b 3.00b 0.05c 0.74b 0.55b 0.16b Non-AMF 25.02d 4.87c 1.04d 1.72a 1.85c 1.71c 0.79c 2.18c 0.15a 0.23d 0.95a 0.12c Influences of three different arbuscular mycorrhizal fungi (AMF) on nutrient concentrations and mycorrhizal nutrient efficiency of peach ( Prunus persica L. Batsch ) seedlings Q.-S. Wu et al (2011) PowerPoint Presentation: Average nutrients removed by some important fruit crops Crop Yield (t/ha) Uptake (kg/ha) N P 2 O 5 K 2 O Banana 40 250 60 1000 Citrus 30 270 60 350 Grapes 20 170 60 220 Mango 15 100 25 110 Papaya 50 90 25 130 Pineapple 50 185 55 350 Passion fruit 15 60 15 75 Apple 25 100 45 180 A. N. Ganeshamurthy ., et al (2011) PowerPoint Presentation: Plants need 17 mineral nutrients (some need 1 or 2 more or less) • The cell membrane is a barrier to uptake of most nutrients To increase uptake, the cell synthesises membrane transporters Synthesis of transporters responds to nutrient deficiency & toxicity Nutrient transporters behave like enzymes Transport can be driven by (a) concentration and electrical gradients (passive transport) (b) metabolic energy (active transport) Conclusion PowerPoint Presentation: Future thrusts Need to study and understand various nutrient uptake mechanisms in horticulture crops to increase the nutrient uptake by crops Need to study of different soil micro organisms which increase the nutrient uptake in fruit crops Need to increase the foliar nutrition application efficiency in fruit crops because the absorb little amount of nutrient through foliar application Present soil nutrition is limiting in crop production, for better uptake of nutrients from soil need to study of every nutrient absorbing mechanisms in horticulture crops Nutrient uptake in problematic soils like alkali and saline soils is limiting the crop productions, through study is needed to increase the nutrient uptake mechanisms in over come this problem

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