Botany Lecture 6 PDF

Water & Nutrient TRANSPORT LECTURE 6 | SEPT. 26, 2024  Photosynthesis Oxygen S u n li g h t C h l o...

Water & Nutrient TRANSPORT LECTURE 6 | SEPT. 26, 2024  Photosynthesis Oxygen S u n li g h t C h l o r o p h y ll Car b oh y drates Car b o n Dio xid e Chlo W ater roplasts Sunlight 6CO2 + 6H 2 O Chlorophyll C6 H 12 O6 + 6O2 Carbon Dioxide Water Glucose Oxygen  Shoot system the above ground part, acquire sunlight and CO2 Root system beneath and into the ground, acquire water and minerals SHOOT ARCHITECTURE AND LIGHT CAPTURE STEMS length of stem tall plants avoid shading from neighboring plants thicker stems, enable greater vascular flow branching patterns enables plants to harvest sunlight for photosynthesis more effectively SHOOT ARCHITECTURE AND LIGHT CAPTURE LEAVES leaf size depends on water availability phyllotaxy arrangement of leaves on a stem (leaf area, leaf orientation)  Shoot system the above ground part, acquire sunlight and CO2 Root system beneath and into the ground, acquire water and minerals ROOT ARCHITECTURE AND ACQUISITION OF WATER AND MINERALS straight or branching in low nitrate zones, roots grow straight without branching to conserve energy and search for nutrients efficiently in high nitrate areas, roots branch extensively to increase absorption. ROOT ARCHITECTURE AND ACQUISITION OF WATER AND MINERALS competition within root systems mycorrhizae (mutualistic associations between roots and fungi) Mycorrhizal hyphae indirectly endow the root systems of many plants with an enormous surface area for absorbing water and minerals, particularly phosphate.  Shoot system the above ground part, acquire sunlight and CO2 Root system beneath and into the ground, acquire water and minerals DIFFERENT MECHANISMS TRANSPORT SUBSTANCES OVER SHORT OR LONG DISTANCES Transport Continuums 01 Apoplastic Route compartmental structure of plants 02 Symplastic Route provides three routes for transport within a plant tissue or organ: 03 Transmembrane Route Long-Distant Transport occurs through bulk flow : the movement of liquid in response to a pressure gradient Sugars are transported from sources to sinks via the phloem translocation : the movement of materials from sugar source - a net producer of sugar leaves to other tissues (ex. leaves photosynthesis) throughout the plant sugar sink - a net consumer or depository of sugar (ex. growing roots, buds, fruits) Long-Distant Transport occurs through bulk flow : the movement of liquid in response to a pressure gradient MAJOR STEPS: Loading Osmosis (Xylem to Phloem) Bulk Flow Osmosis (Phloem to Sink) TRANSPIRATION DRIVES THE TRANSPORT OF WATER AND MINERALS FROM ROOTS TO SHOOTS VIA THE XYLEM  Water & Nutrient TRANSPORT LECTURE 6 | SEPT. 26, 2024