BOTANFUN Plant Tissues and Roots PDF

3. Aerenchyma PLANT TISSUES ○ Has large air spaces between cells ○ Ex. Dieffenbachia Petiole BOTAFUN – Fundamentals of Botany...

3. Aerenchyma PLANT TISSUES ○ Has large air spaces between cells ○ Ex. Dieffenbachia Petiole BOTAFUN – Fundamentals of Botany 4. Stellate parenchyma Instructor: Dr. Esperanza Maribel Guiao Agoo ○ Irregularly shaped cells ○ Filler cells ○ Ex. Canna indica petiole OUTLINE I. Basic Plant Morphology Collenchyma A. Types of Plant Cells and Tissues 1. Parenchyma Grouped in strands and help support young parts of the 2. Collenchyma plant shoot 3. Sclerenchyma They have thicker and uneven cell walls B. Basic Tissue Types These cells provide flexible support without restraining 1. Dermal growth 2. Ground More common in plants that are not rigid 3. Vascular C. Meristems Stems are not too soft and not too hard Ex. vines BASIC PLANT MORPHOLOGY Two systems ○ Shoot system - above the ground ○ Root system - below the ground Six organs ○ Root ○ Stem ○ Leaf ○ Flower ○ Fruit ○ Seed Sclerenchyma PLANT TISSUES Schelerenchyma cells are rigid because of thick secondary walls strengthened with lignin, and indigestible strengthening polymer TYPES OF PLANT CELLS AND TISSUES The cells are dead at functional maturity Fundamental cell/tissue types: Two types 1. Parenchyma cell -> parenchyma tissue ○ Sclereids 2. Collenchyma cell -> collenchyma tissue Short and irregular in shape and 3. Schlerenchyma cell -> schlerenchyyma tissue have thick lignified secondary walls Parenchyma Alive at maturity Have thin and flexible primary walls; lack secondary walls They are active Perform the most metabolic functions ○ Photosynthesis ○ Storage ○ Fibers ○ Secretion Long and slender and arranged in Retain the ability to divide and differentiate threads ○ Mitosis Wound healing Cloning ○ Protection (epidermis) Types 1. Chlorenchyma ○ Has chloroplasts ○ Function for photosynthesis ○ Ex. Hydrilla Verticillata 2. Storage parenchyma ○ Store carbohydrates ○ Has amyloplastids - storage ○ Ex. potato ○ Stained with iodine - dark purple to signify presence of starch Castilla, Selene Mari D. | 1 BOTAFUN – PLANT TISSUES AND ROOTS BASIC TISSUE TYPES Based on location and function 1. Dermal 2. Ground 3. Vascular 3. Periderm ○ Protective covering ○ Composed of cork and parenchyma 4. Secretory structures ○ Responsible for making latex, resins, nectar, and other substances produced and stored in channels inside the plant body. Dermal Cells that form the epidermis or skin of cells MERISTEMS Can be found in roots to stem and surface of leaves Made up of parenchyma cell/tissue The plants’ growing points are called meristems For protection Types Epidermis ○ Primary/apex ○ Stomates, trichomes, & roots hairs - extensions Shoot apex of epidermis Root apex ○ thin, one or two layers ○ Secondary/lateral Vascular cambium Cork cambium Ground Cortex and pith ○ Groups of cells/tissues which fill up the space between the epidermis and around the vascular tissues Like filler cells Made up of parenchyma, collenchyma and/or sclerenchyma cells For storage Vascular Xylem and phloem Made up of parenchyma and sclerenchyma tissue Found in the middle part Responsible for the transport of food and water For transport of food and water Complex Tissues 1. Xylem ○ Water conducting tissue ○ Parenchyma fibers, vessels and/or tracheids, and ray cells ○ Mostly to conduct water and nutrients ○ E.g. roots to shoots 2. Phloem ○ Food conducting tissue ○ Sieve-tube members (no nucleus at maturity, cytoplasm present), companion cells, fibers, parenchyma, and ray cells. ○ Mostly to conduct sugars, amino acids, etc. ○ E.g. leaves to roots or flowers Castilla, Selene Mari D. | 2 ROOTS REGIONS OF ROOT TIP BOTAFUN – Fundamentals of Botany Instructor: Dr. Esperanza Maribel Guiao Agoo OUTLINE I. Roots A. Types of Root System 1. Taproot System 2. Fibrous Root System B. Regions of Root Tip C. Monocot Root ROOTS Below ground Plants develop from the seed, root develops first Main functions Root Cap ○ Anchorage Can hold on to the soil Parenchymatous ○ Absorption a small tissue at the tip of the root Absorb water and nutrients from soil protects the root from environmental stress and functions ○ Conduction in gravity perception In plants, food are different from nutrients assists the root in making a path through compact soil by ○ Food are produced secreting mucilage and protecting the RAM ○ Nutrients are absorbed Covers delicate root apical meristem Roots appear early as an embryonic root or radicle Detects gravity so root grows downwards (positive gravitropic) Secretes mucilagenous substances that meristems ground TYPES OF ROOT SYSTEM and facilitates root penetration and nutrient absorption Can be destroyed Taproot System Apical Meristem A root system consisting of one prominent main root with smaller lateral roots branching from it Region of cell division Meristematic activity give rise to the primary plant body and are responsible for Fibrous Root System the extension of the roots and shoots A root system consisting of several adventitious roots of approximately equal size that arise from the base of the Region of Elongation stem No main primary root Cells stop dividing here Spread around the plant Region of differentiation of cells Shallow and spreading to prevent erosion Protoderm, procambium, ground meristem arises Tissues are not yet permanent Region of Maturation Specialization happens here Protoderm -> epidermis Procambium -> xylem and phloem Ground meristem -> cortex and pith Cells assume specific functions Newer cells are pushed downwards; older cells move upward MONOCOT ROOT Epidermis ○ Outermost layer, single layered ○ Parenchymatous Cortex ○ Larger, thin-walled ○ Parenchymatous - storage parenchyma ○ For storage of carbohydrates Castilla, Selene Mari D. | 1 BOTAFUN – ROOTS Endodermis ○ inner skin, single layered ○ Regulate entry of water ○ Has suberin - wraps cell wall Water cannot pass through easily ○ Passage cell Cell without suberin Water passes through here Like a gate ○ Casparian strip Suberin material only in certain cells Ring-like cell-wall modifications in the root endodermis of vascular plants Pericycle Xylem ○ Made up of parenchyma cells, has thin cell walls ○ Cells are bigger - like pipes ○ Can undergo cell division Because water has to go from roots to ○ A layer of cells just inside the endodermis of the the top root ○ Arranged in a ring ○ Gives rise to lateral roots - extensions Phloem Lateral roots arise from the pericycle ○ Smaller of the stele Because food went from the top to the roots, it’s the final pipe Pith ○ Big space in the middle ○ Looks the same as cortex ○ Parenchymatous ○ For storage DICOT ROOT Same from epidermis to pericycle The difference is seen after the pericycle. Xylem in the middle and phloem in the corners No pith Castilla, Selene Mari D. | 2 BOTAFUN – ROOTS LATERAL ROOTS VS ROOT HAIRS Twining roots Lateral root Allow the plant to attach to a certain thing ○ Secondary root ○ Originates from inside the root - pericycle Photosynthetic roots Root hairs ○ Originates from the epidermis Grows on another plant Roots can photosynthesize Common in orchids MODIFIED ROOTS Not for anchorage, absorption, and conduction Symbiotic Roots Food storage Propagative roots Mycorrhiza Pneumatophores ○ A mutually beneficial association between a Aerial roots fungus and a root that helps the plant absorb Photosynthesis roots of some orchids essential minerals from the soil Contractile roots some herbaceous dicots and monocots Fungus Buttress roots Provides protection against Parasitic roots some types of pathogens Symbiotic roots Increase the surface area ○ Mycorrhizae or “fungus” roots for the absorption of ○ Legumes (e.g. pea, beans, peanuts) and essential nutrients (e.g. bacterium from root nodules phosphorous) from the soil Plant Provides food for the Buttress roots fungus in the form of sugar Aka plank roots and amino acids Swollen bases or braces that hold trees upright Nodule Aid in extensive distribution of shallow roots ○ A small swelling on the root of a leguminous Found in some tropical rainforest trees plant in which beneficial nitrogen-fixing Can be seen in very tall trees, rainforests bacteria (Rhizobium) live Do not need deep roots - has shallow root system ○ Legumes (e.g. pea, beans, peanuts) form root Extra support on the side nodules ○ Mutualism between a plant and bacterium Bacteria fix atmospheric nitrogen to Pneumatophores form that the plant can utilize A specialized aerial root produced by certain trees living in Plant provides food and shelter to swampy habitats bacteria May facilitate gas exchange between the atmosphere and submerged roots Cluster roots For plants that are submerged in water Oxygen scarcity Aerial plants Extensions that can get oxygen from the air Very fine roots Roots that grow vertically upwards to get oxygen for For absorbing moisture in teh air respiration by plants growing in swampy areas Extra water source Ex. mangroves Parasitic roots Adventitious Roots Infect the branches of another plant Stilt roots Cannot undergo photosynthesis by its own ○ Develop from the base of stem nodes Ex. mistletoe ○ Shorter Invade the inside of the root of the other plant ○ Non-hygroscopic Prop roots Storage roots ○ Aerial roots ○ Lengthy For carbohydrate storage ○ Hygroscopic - can absorb water from the Ex. sweet potatoes, carrots, cassava, yam bean, atmosphere Can arise from stem or roots ECONOMIC IMPORTANCE OF ROOT Provide stability Rootcrops as sources of starch ○ Predominantly taproots Balete Tree Carrots, beets, sugar beets, parsnips, Aerial roots turnips, radishes ○ Some fibrous roots Sweet potatoes, cassava Contractile Roots Some roots are used as flavorings Specialized root, often found on bulbs or corms, that ○ Ex. root beer flavoring (dried greenbrier roots) contracts and pulls the plant to a desirable depth in the Medicine soil Castilla, Selene Mari D. | 3  ○ Lenticels - small openings, like slits STEMS BOTAFUN – Fundamentals of Botany Instructor: Dr. Esperanza Maribel Guiao Agoo OUTLINE I. Stems A. Shoot Morphology B. Shoot Apex C. Monocot Stem D. Herbaceous Dicot Stem E. Plant Growth 1. Onset of Secondary Growth F. Summary Monocots G. Xylem 1. Cactus ○ Node - circular, goes all around 2. Coconut Tree ○ Broad sheath - no petiole H. Phloem I. Trichomes J. Modified stems 1. Corm 2. Tuber 3. Bulb 4. Photosynthetic stem 5. Rhizomes 6. Thorn and Spine 7. Tendrils 8. Phylloclades 9. Cladophylls 10. Banana K. Economic Importance of Stems 1. Wood 2. Bamboo SHOOT APEX 3. Fibers Direction of growth in upward 4. Bark Growth is at the tip - apex (apical meristem) Leaf primordia - very young leaves Protoderm STEMS Procambium Shoot system Ground meristem ○ Photosynthesis ○ Reproduction ○ Storage ○ Transport ○ Hormones Root system ○ Anchorage ○ Absorption ○ Storage ○ Transport ○ Hormones Main functions of stems ○ Support Leaves and reproductive structures ○ Conduct Water, dissolved minerals, carbohydrates ○ Produce new living tissues MONOCOT STEM At apical meristems At lateral meristems (secondary Vascular bundles are scattered all throughout the stem growth) Just ground tissue - no cortex and pith Vascular bundles ○ Xylem - eyes SHOOT MORPHOLOGY ○ Phloem - forehead Dicots ○ Bundle sheath - all around ○ Node - points of attachment ○ Bundle cap - thick bundle sheath ○ Lateral buds - meristematic tissue ○ Leaf scar - when leaves fall off from node Castilla, Selene Mari D. | 1 BOTAFUN – STEMS Red ones are sclerenchymatous cells - become fibers when a plant disintegrates HERBACEOUS DICOT STEMS PLANT GROWTH There is a clear pith and cortex - parenchymatous Plants grow taller and wider Vascular bundles are neatly arranged in a ring They have meristematic tissues within the body that allows Epidermis widening through active mitosis Cortex Region of vascular bundles ○ Neatly arranged in a ring ○ Bundle cap/phloem fiber cap (sclerenchymatous cells) - top of phloem ○ Phloem - on top of xylem ○ Vascular cambium - In between the xylem and phloem ○ Xylem - facing the pith / lower half Pith Pith rays ○ Parenchymatous ○ Extensions of pith ○ Radiate towards the outside Collenchymatous tissue ○ For flexibility ○ Stem of vines or epiphytes that twine around bigger plants to grow higher ○ Needs to bend ○ Gives vines the flexibility Castilla, Selene Mari D. | 2 BOTAFUN – STEMS Onset of Secondary Growth Cell division of vascular cambium causes secondary growth In the herbaceous dicot stem, the vascular cambium is there but it is not active In woody dicot stems, vascular cambium is there and becomes active after undergoing cell division Vascular cambium ○ Very thin tissue ○ Dividing line between xylem and phloem ○ Pushes primary xylem inward ○ Pushes primary phloem outward ○ Eventually crushes the pith Cork is growing outside so the space inside is limited, the pith is compromised Cork cambium 3 year old woody dicot ○ Part of cortex that undergoes cell division ○ Produces cork - new cells produced by cork cambium Periderm ○ Cork + cork cambium Bark ○ Periderm + all phloem tissues Wood ○ Central portion ○ Xylem and pith ○ Vascular cambium is in between the bark and the wood Young woody dicot stem Pith is not yet crushed, but you can see the woody material Castilla, Selene Mari D. | 3 BOTAFUN – STEMS Trees without heartwood ○ No heartwood - can be prone to damage ○ Sapwood is the functional unit so it could still Sapwood live ○ The outer layer of wood that is lighter ○ Younger xylem SUMMARY ○ Functional portion of the wood ○ The one that transports water Heartwood ○ The inner layer of wood ○ Older xylem ○ Doesn't work anymore ○ Dead ○ More sturdy and used for various products Annual ring ○ 1 year ○ In temperate region, counting of annual rings are more accurate than in tropical regions ○ Temperate region XYLEM Winter Schlerenchymatous Metabolism slows/stops Vessels elements Summer ○ Look like pipes longitudinally Metabolism continues a ○ In cross-section, they look like big circles The mark signifies the season Tracheids ○ Springwood ○ Look narrower Lighter ○ Have narrow tips Bigger xylem ○ They are overlapping side by side ○ Summerwood/Latewoord ○ Spindle shaped Darker ○ For the gymnosperms like pine trees Narrower xylem Pit fields ○ Thinned portions of cell wall ○ For transport of water Resin Ducts ○ Found within the wood ○ In gymnosperms Petrified wood ○ Fossilized ○ Should be surrendered to the govt for educational purposes Castilla, Selene Mari D. | 4 BOTAFUN – STEMS Cactus When it dies, the epidermis, cortex, and ground tissues easily decompose The xylem tissue remain very sturdy Coconut Tree Monocot Has very sturdy xylem When tree disintegrates, xylem remains as fibers PHLOEM Phloem cells conduct food from leaves to the rest of the plant. They are alive at maturity and tend to stain green (with the stain fast green). Phloem cells are usually located outside the xylem. The two most common cells in the phloem are the companion cells and sieve cells. Companion cells retain their nucleus and control the adjacent sieve cells. Dissolved food, as sucrose, flows through the sieve cells. Sieve tube members ○ Pipe-like ○ Responsible for main transport of food ○ Carbohydrates Dark elements inside sieve tube ○ Sieve Plate Connection sites between sieve elements MODIFIED STEMS Small pores aid in the transportation Take up functions that is not the usual function of the stem and uptake of food particles Does not look like normal stem Companion cells ○ Narrower cells ○ Smaller in size Corm A short, thickened, underground stem specialized for food storage and asexual reproduction Instead of being a stem, it functions as a storage carbohydrate Can undergo cellular respiration Ex. Taro/Gabi (Colocasia esculenta), Water chestnut (Eleocharis dulcis), Crocus Tuber The thickened end of a rhizome that is fleshy and enlarged for food storage Has nodes and lenticels Tubers and corms are interchanged, not really much of a difference Ex. white potato (Solanum tuberosum), Yam (Dioscorea TRICHOMES esculenta), Artichoke (Helianthus tuberosus) Hair-like structure For protection against predators Glandular ○ Have bulbs at the tips ○ Have toxic substances at their tips Non-glandular ○ Stinging Castilla, Selene Mari D. | 5 BOTAFUN – STEMS Bulb Phylloclades A rounded, fleshy underground bud that consists of a short Succulent stems stem with fleshy leaves Stems do the photosynthesis because the leaves are too Ex. Onion (Allium cepa), Garlic (Allium sativum), Shallots small (Allium oschaninii), broccoli, cauliflower, cabbage Stems stores water Can also be classified as photosynthetic stems Photosynthetic Stem Needle-like structures Cladophylls Each needle is a stem - has nodes Leaves are the small structures There are scale-like leaves in the nodes The leaf look-alike is the stem - cladophyll These trees are in dry environments, they have to Ex. ruscus, asparagus conserve water. They can't afford to have very broad leaves. Needle-like stem can undergo photosynthesis because the leaves are too small Rhizomes Underground stems Banana For storage and reproduction The trunk of the banana is not the stem, it’s still a leaf Creeping The real stem is underground Can spread It’s a corm - for storage and reproduction Ex. grasses - stolons, ginger (Zingiber officinale), Alpinia Suckers - young plant grown from corms sp. Thorn and Spine ECONOMIC IMPORTANCE OF STEMS Thorn 1. Food ○ Modified stem 2. Medicine ○ Still has leaves 3. Paper Spine 4. Resin ○ Modified leaf 5. Fuel ○ No leaves, only sharp object 6. Lumber Uses of Wood House materials: doors, floors, etc. Musical instruments: violins, pianos Bamboo Tendrils Substitute for wood Found at tip of stem Absorb the weight of the person They twirl Useful for flooring Can also be called pads - for the attachment For skateboards - lightweight Plyboo - plywood but bamboo Fibers Cloth Paper Hemp - made into ropes Castilla, Selene Mari D. | 6 BOTAFUN – STEMS Bark Cinnamon Rubber - from injuring the bark Myrrh ○ Soaps ○ Perfumes ○ Collected from saps of the bark ○ Myrrh Gum - Cammiphora Collected, dried and made into incense Resin - Agathis Agarwood ○ Aka Oud ○ Light colored ○ Can be infected by fungus ○ Made into agarwood oil - 1L = $50-50K Aloeswood ○ Infected agarwood ○ Smells very nice ○ Very expensive ○ Depend on color and smell ○ Products Incense Beads Wooden Fans Sculptures Furniture Rattan - furniture Amber ○ Formed from resin exuded from tree bark ○ Produced in the heartwood Castilla, Selene Mari D. | 7  Auricle LEAVES ○ Ear-like structure ○ Appendage that surrounds the stem at the BOTAFUN – Fundamentals of Botany junction of the blade and sheath Instructor: Dr. Esperanza Maribel Guiao Agoo ○ Protection from dirt OUTLINE I. Leaves A. Leaf Anatomy 1. Monocot Anatomy 2. Dicot Anatomy B. Leaf Morphology 1. Types of Leaves 2. Venation 3. Phyllotaxy 4. Leaf Shape 5. Base 6. Margin Dicot Anatomy 7. Apex C. Stomata Leaf lamina 1. Pea Leaf Stoma ○ Blade 2. Factors Petiole D. Internal Anatomy 1. Monocot leaf ○ Holds the leaf 2. Dicot Leaf ○ Cylindrical stalk of the leaf E. Modified Leaves Node 1. Pitcher plant ○ Point of attachment of the petiole 2. Pitfall traps Internode 3. Tendrils ○ The area between two nodes 4. Bracts Axillary bud 5. Insect galls 6. Enlarged petiole ○ Small bud 7. Reproductive leaves ○ Angle between the stem and the leaf 8. Phyllodes Stipule 9. Scale leaves ○ Small leaf at the base of the petiole 10. Bulb scales 11. Thorns and spines 12. Pseudostem LEAVES Shoot system ○ Stem ○ Leaves ○ Flowers ○ Fruits LEAF ANATOMY Monocot Anatomy LEAF MORPHOLOGY Node Can be characterized based on: ○ Point of attachment of leaves on the stem ○ Type of leaves Sheath ○ Venation ○ Directly attached to the node ○ Phyllotaxy ○ Embraces stem ○ Leaf shape ○ Equivalent to petiole in dicots ○ Base Blade or lamina ○ Margin ○ Extension of sheath, flat structure ○ Apex Leaf scars ○ Seen in the node ○ Circles the node Type of Leaves ○ Ringlike structure Simple Ligule ○ One leaf attached directly to stem ○ Collar extension of the sheath curving around ○ Has an axillary bud at the base of the petiole or the stem; membranous, hairy or absent at the axil ○ Has petiole and blade and have midrib as the main vein Castilla, Selene Mari D. | 1 BOTAFUN – LEAVES ○ Peltate Venation Like umbrella Intersects in the middle Parallel venation ○ Perfoliate leaves ○ Veins running parallel with one another Petiole is not evident ○ Monocot Leaf is inserted around the stem Netted ○ Pinnately-netted leaves One primary vein (midvein) which is included within an enlarged midrib ○ Palmately veined leaves Several primary veins fan out from the base of the blade There can be exceptions ○ Monocots do not only have parallel veins ○ Dicots dont only have netted veins ○ Ex. Banana leaf - monocot but the veins are netted Papaya leaf - simple leaf but looks compound Compound ○ Has smaller leaves (leaflets) attached to small branch ○ Petiolule - small stalk of the leaflets ○ Rachis - long stalk ○ Has main stem but is further divided ○ Take note of the axillary bud, compound leaves only has one axillary bud at the node of its petiole ○ Pinnately leaflets arranged along the middle vein ○ Palmately compound leaves radiate outwards from the end of the petiole Phyllotaxy Arrangement of leaves on the stem Opposite ○ Opposite side Alternate ○ One above the other Basal ○ Leaves only on the base Whorled ○ Leaves go around Decussate ○ Opposite but different directions Distichuous ○ Arranged alternately in two opposite vertical rows Castilla, Selene Mari D. | 2 BOTAFUN – LEAVES Leaf Shape Apex Shape or outline Linear ○ Elongated and thin ○ Ex. grasses Lanceolate ○ Like spear ○ Elongated but wide in the middle Ovate ○ Oval shape ○ Very wide at the midpart but not as long as lanceolate Cordate ○ Heart-shape ○ Lower part is wider STOMATA Stomata pore - space in between Guard cells - two cells look like beans Subsidiary cells - 2, 4 or 6 Pea Leaf Stoma To facilitate gas exchange between the inner parts of leaves, stems, and fruits, plants have a series of openings known as stomata (singular stoma) Factors affecting stomatal movement Base 1. Light generally causes it to open and darkness closes it ○ Phototropins expressed in guard cells act as major blue light receptors for stomatal opening ○ Phototropins are plant-specific blue light receptor proteins for phototropism, chloroplast movement, leaf expansion, and stomatal opening. 2. Low water/moisture availability causes it to close to prevent further water loss 3. Temperature changes - higher temperature will cause stomata to close to prevent water loss 4. CO2 concentration - low concentration causes it to open Depending on the environment, some species develop their own adaptations Floating leaves ○ Stomates only on the upper epidermis Margin Submerged leaves ○ No stomates Castilla, Selene Mari D. | 3 BOTAFUN – LEAVES Desert plants 1. Thick and reduced leaves 2. Stomata opens only at night time 3. Thick waxy layer INTERNAL ANATOMY Monocot Leaf Has upper epidermis and lower epidermis Dicot Leaf ○ Both one layer thick so that they can easily Has its own vascular bundle on its midrib absorb gases to the stomates Upper epidermis Stomates are usually at the lower epidermis Mesophyll layer ○ For water retention ○ Divided into ○ Protection from damage ○ Palisade Parenchyma - upper Monocots can roll their leaves so they also have stomates Elongated cells undergo at the upper epidermis photosynthesis Bulliform cells They are elongated to maximize ○ Point where the leaf is under stress when it folds photosynthesis over ○ Spongy Parenchyma - lower ○ For leaf rolling Leaf rolling ○ Adaptation of monocot leaves against too much heat exposure for water conservation Mesophyll ○ In between the lower and upper epidermis ○ Uniform cells ○ Here you will see the vascular bundles Vascular bundles ○ Each one represents one vein ○ Has xylem and phloem ○ Xylem - bigger ○ Phloem - smaller Cuticle ○ Protects epidermal layer from heat exposure Castilla, Selene Mari D. | 4 BOTAFUN – LEAVES Scale Leaves Nail size Scale like To prevent too much water loss Bulb scales For protection of modified stems Contains carbohydrates Ex. onion (allium cepa), garlic (allium sativum), shallots (allium oschaninii) Thorns and Spines Thorn - modified stem Spine - modified leaf ○ For protection of younger parts of the plant ○ Involucre spine - protect flower ○ Petiolar spine - spines that develop as a leaf MODIFIED LEAVES part with a midrib, petiole, and secondary veins ○ Ex. cactus, palm trees, Pitcher Plant Pseudostem Pitcher is found at the tip of the leaves Ex. main stalk of banana - it’s a leaf Dissolve organic materials that get trapped inside the pitcher Pitfall Traps Dionaea muscipula Drosera rotundifolia For additional nutrition of the plants Tendrils Extension of the leaf It may curl For support of the plant Bracts Look like petals of flowers They are colorful to attract pollinators Ex. poinsettia, bougainvillea ○ The real flower of bougainvillea is the small white one Insect Galls abnormal plant growths caused by insects, mites, nematodes, fungi, bacteria and viruses There are insects inside Enlarged Petiole Ballooned stalk of the leaf For the buoyancy of aquatic plants Reproductive Leaves The margins of the leaves can grow young plants Can undergo mitosis and produce young plants Ex. katakataka Phyllodes Flattened petiole Means of conserving moisture in dry areas Castilla, Selene Mari D. | 5  ○ There is also water and nutrients TRANSPORT OF MATERIALS BOTAFUN – Fundamentals of Botany Instructor: Dr. Esperanza Maribel Guiao Agoo OUTLINE I. Transport of Materials A. Soils B. Nutrient Classification C. Nutrient Absorption D. Water Absorption E. Water Transportation 1. Root Pressure 2. Capillary Action 3. Cohesion Forces NUTRIENT CLASSIFICATION 4. Transpiration Pull F. Transpiration Amount 1. Factors ○ Macronutrients 2. Stomats H, C, O, N, K, Ca, Mg, P, S a) Factors Needed in big amounts G. Plant Response 1. Salt Water ○ Micronutrients 2. Aerenchyma Cl, B, Fe, Mn, Zn, Cu, Mo H. Translocation of Substances in the Needed in small amounts Phloem Just to balance ions in cells, for 1. Bulk Flow and transport, part of functional groups Movement of Food and ○ Both are equally important Water 2. Pressure Flow Model of ○ Essential nutrients needed Transport Function ○ Constituents of organic material: C, H, O, N, S ○ Osmotic potential or contribute to enzyme TRANSPORT OF MATERIALS structure/function: K, Na, Mg, Ca, Mn, Cl ○ Structural factors in methalloproteins: Fe, Cu, Tallest trees Mo, Zn ○ Sequoia sempervirens ○ Petersianthus quadrialatus NUTRIENT ABSORPTION Having lots of oxygen in the soil is advantageous Oxygen is absorbed by the roots Oxygen is then used for cellular respiration After they respire, CO2 and water are released CO2 produced from respiration go out of the root and mixes with water in the soil *see equation in the photo Carbonate compound is made It then breaks up as Carbonate ion & H+ H+ then binds to the clay or soil particle in exchange of the nutrient which then goes into the roots Called exchange mechanism Requirements for the exchange mechanism 1. There must be oxygen in the soil 2. Soil must be loose and not compact 3. There must be oxygen SOILS Weathering parent rock ○ Below the surface of the ground ○ Where all the other soils come from through weathering Subsoil ○ After weathering of the parent rock Topsoil ○ Can become very thick because of the weathering ○ Can also be thin but it will easily erode ○ Living soil ○ Oxygen is limited in this area ○ This is why soil is loosened up, for it to have spaces for oxygen to be consumed by the roots Castilla, Selene Mari D. | 1 BOTAFUN – TRANSPORT OF MATERIALS WATER ABSORPTION Transpiration Pull Once the nutrients have been absorbed by the roots, they Pull from the top from the leaves will now move towards the inside of the roots, then they Sucking of water from the leaves bring it to the stem Happens when stomates are open From the roots, water pass through the epidermis, water will move in between the cells, because water is easier to TRANSPIRATION move in between cells Apoplastic route Water moves out of the stomate ○ In between the cells More water inside compared to outside ○ Easier because they dont need to go through Less water outside compared to the inside the regulatory role of cell membrane ○ They just seep in between cells Factors That Affect Transpiration Symplastic route ○ Pass through the cells Dry environments ○ They regulate water before it can go inside High temperature Next, water goes through the endodermis ○ Water molecules become dispersed Endodermis Humidity is low ○ Regulate the amount of water going inside Windy ○ Has Casparian strips But, if it’s too windy or too hot and the plant is losing too Casparian strips much water, stomates close by itself ○ Suberin materials Low soil moisture lowers transpiration ○ Found in between endodermal cells ○ The blockage that regulates the flow of water and nutrients WATER TRANSPORTATION Then, water moves to the xylem where it is transported How can water continue moving up? ○ Water has an affinity to xylem wall - adhesion Stomates ○ Water pulls other water molecules upward - cohesion Entry point of CO2 ○ Basically push from below (water pressure) Exit point of H2O and pull from the top (the following forces) Guard cells - around stomata pore Subsidiary cells - protects guard cells Open in the day and closed at night - need carbon dioxide Water/Root Pressure in the daylight for photosynthesis Water also builds up and causes pressure within the roots When water is scarce, plant wilts and guard cells become Water is pushed upwards to the stem flacid Abscisic acid - plant hormone that causes K+ to pass out of cells and guard cells become flacid Capillary Action High levels of CO2 cause guard cells to become flacid Force that keeps water moving up Leaves lost when water is scarce Liquid flows through narrow spaces without external forces, such as gravity; rather, the liquid's movement is Factors Affecting Stomates aided by intermolecular forces present in between the liquid and solid surface CO2 ○ If there is little CO2, stomates open Co2 causes K+ and H2O to rush Cohesion Forces inside guard cells - bloat and open Water moves up because other water molecules pull them ○ If there is many CO2, stomates will close Continuous stream Water and CO2 rushes out Castilla, Selene Mari D. | 2 BOTAFUN – TRANSPORT OF MATERIALS Water TRANSLOCATION OF SUBSTANCES IN THE ○ If there’s too much water, they open PHLOEM There are two steps in translocation that require energy: ○ Loading is the active transport of sucrose and other solutes into the sieve tubes at a source. Load food to phloem ○ Unloading is the active transport of solutes out of the sieve tubes at a sink. Phloem to the different parts of the plant body Bulk Flow and Movement of Food and Water Pressure Flow Model of Transport PLANT RESPONSE Source sieve tube cells have a greater sucrose concentration than surrounding cells Salt Water ○ Water enters by osmosis ○ Causes greater pressure potential at the source, Response to flooding so that the sap moves by bulk flow towards the Salt must be excluded, actively secreted, or diluted as it sink enters. Sucrose is unloaded actively at the sink, maintaining the ○ Mangroves has pneumatophores solute and water potential gradients. Aerenchyma Plants submerged underwater only has stomates on the upper side and has aerenchyma cells Transport of food can also happen from the lower parts of the plants upward. ○ In modified roots or stems ○ Sink becomes the source Castilla, Selene Mari D. | 3 BOTAFUN – TRANSPORT OF MATERIALS Translocation (movement of organic solutes) stops if the phloem is killed. Translocation often proceeds in both directions - both up and down in the stem simultaneously (but not within the same tube) Translocation is inhibited by compounds that inhibit respiration and the production of ATP. Castilla, Selene Mari D. | 4 BOTAFUN – TRANSPORT OF MATERIALS Xylem: Structure: Pathway of Water Tracheary Elements: 1. Root Uptake: Tracheids: Long, tapering cells with overlapping Root Hairs: ends. Found in all vascular plants. Extensions of root epidermal cells that increase Vessel Elements: Shorter, wider cells with the surface area for water absorption. perforations in their walls. Present in Absorb water and minerals from the soil. angiosperms. Passive Transport: Non-Conducting Cells: Water moves through the root cells by osmosis, Fibers: Provide structural support. following the concentration gradient. Parenchyma Cells: Involved in storage. Active Transport: Function: Minerals are actively transported into the root Water Transport: cells against the concentration gradient. Xylem transports water and minerals from the 2. Apoplastic and Symplastic Pathways: roots to the rest of the plant. Apoplastic Pathway: Cohesion-Tension Theory: Explains the Water moves through the cell walls and spaces movement of water through the xylem. outside the cells (apoplast). Transpiration: Limited by the Casparian strip in endodermal Loss of water from the leaves through stomata cells, which forces water into the symplastic creates a negative pressure, pulling water pathway. upward. Symplastic Pathway: Capillarity: Water moves through the cytoplasm of cells via Water moves through the small diameter of plasmodesmata. xylem vessels due to capillary action. Controlled by the selective permeability of the Root Pressure: plasma membrane. Active transport of minerals into the xylem at the 3. Endodermal Barrier: root creates a positive pressure. Casparian Strip: A waxy, impermeable layer in the radial walls of Phloem: endodermal cells. Structure: Forces water and minerals to cross the plasma Sieve Elements: membrane, ensuring selective uptake. Sieve Cells: Present in gymnosperms. 4. Vascular Tissues (Xylem): Sieve Tube Elements: Present in angiosperms. Root Pressure: Lack a nucleus and have perforated sieve Active transport of minerals into the xylem at the plates. root creates a positive pressure. Companion Cells: Forces water up the xylem. Connected to sieve tube elements via Capillary Action: plasmodesmata. Assist in loading and unloading Water moves through the xylem vessels due to of substances. capillary action. Function: 5. Transpiration: Transport of Organic Solutes: Stomatal Regulation: Translocation involves the movement of sugars, Stomata on leaves open for gas exchange amino acids, and other organic compounds. during photosynthesis. Pressure Flow Hypothesis: Describes the Water vapor exits through stomata during mechanism of phloem transport. transpiration. Source-Sink Relationship: Cohesion-Tension Theory: Source tissues (photosynthetic) produce sugars Explains the movement of water through the through photosynthesis. xylem. Sink tissues (growing regions, storage organs) Water molecules cohesive and adhesive forces consume or store these sugars. contribute to the upward pull. Loading and Unloading: 6. Leaf Tissues: Active Loading: Companion cells pump solutes Mesophyll Cells: into sieve tube elements. Contain chloroplasts for photosynthesis. Passive Unloading: Sinks remove solutes from Water is needed for photosynthesis, and excess sieve tubes. water exits through stomata. Regulation and Coordination: Guard Cells: Environmental Factors: Control the opening and closing of stomata, Temperature: Affects the rate of transpiration. regulating water loss. Humidity: Influences water potential gradients. 7. Atmosphere: Light: Stimulates photosynthesis, affecting sugar Evaporation: production. Water molecules in mesophyll cells evaporate Hormonal Regulation: into the intercellular spaces. Abscisic Acid (ABA): Controls stomatal closure Water vapor diffuses out through stomata into in response to water stress. the atmosphere. Cytokinins, Gibberellins, and Auxins: Influence 8. Xylem Transport: growth and development. Xylem Vessels: Water Potential: Transport water and minerals from roots to Water Potential Gradient: Drives the movement shoots. of water. Operates on the principles of cohesion and Osmosis: Movement of water across cell adhesion. membranes. Castilla, Selene Mari D. | 5 BOTAFUN – TRANSPORT OF MATERIALS Cells needed 6. Xylem transports water, minerals, and nutrients from the In the Roots: soil to all the plant parts. Root Epidermal Cells: 7. There are two types of "transport" tissues in plants- xylem Location: Outermost layer of the root. and phloem. Function: Absorption of water and minerals. 8. Water and solutes are transported by the xylem from the Special Features: Bear root hairs to increase roots to the leaves, and food is transported from the surface area. leaves to the rest of the plant by the phloem. Root Hairs: 9. The process by which water evaporates from the leaves Location: Extensions of root epidermal cells. and draws more water from the roots is called Function: Increase surface area for water and ‘transpiration’. mineral absorption. Endodermal Cells: Location: Inner layer of the root, surrounding the vascular tissue. Function: Regulate the entry of water and minerals into the vascular cylinder. Special Features: Casparian strip for selective uptake. In the Stem: Xylem Vessel Elements: Location: Vascular tissue (xylem). Function: Transport water and minerals from roots to shoots. Types: Tracheids (in all vascular plants) and Vessel Elements (in angiosperms). Phloem Sieve Tube Elements: Location: Vascular tissue (phloem). Function: Transport organic solutes (sugars, amino acids) from source to sink. Special Features: Lack a nucleus, have perforated sieve plates. Companion Cells: Location: Associated with sieve tube elements in the phloem. Function: Assist in loading and unloading of substances in the phloem. Parenchyma Cells: Location: Throughout the plant, including the stem. Function: Storage and metabolism. In the Leaves: Mesophyll Cells: Location: Photosynthetic tissue in the leaf. Function: Contain chloroplasts for photosynthesis. Water Role: Water is needed for photosynthesis. Guard Cells: Location: Surrounding stomata on leaf surfaces. Function: Regulate the opening and closing of stomata, controlling water loss. General Cells Involved: Root Pressure Cells: Location: Root cells. Function: Active transport of minerals into xylem, creating root pressure. Stomatal Cells: Location: Leaf epidermis. Function: Control the opening and closing of stomata, regulating water loss. Byjus Water transport in plants: 1. Xylem transports plant water and minerals. 2. Root hair is the hair found in the roots of plants. 3. These root hairs absorb water and minerals from the soil because they are in direct contact with the water film between the soil particles. 4. Through the diffusion process, water enters the root hairs. 5. The xylem is made up of small vessels that connect the roots and leaves. Castilla, Selene Mari D. | 6