Roots, Stems and Leaves - Botany - Lecture Slides, Slides of Botany and Agronomy

Download Roots, Stems and Leaves - Botany - Lecture Slides and more Slides Botany and Agronomy in PDF only on Docsity! Roots, Stems and leaves apical meristem terminal bud _ SHOOT SYSTEM ROOT SYSTEM Docsity.com What are the primary functions of roots? Major Functions of RootS aaa» Storage — Conduction of f ( water and solutes Absorption of # water and mineral Anchorage of plant in soil Docsity.com Dicot root, l.s. : \ ei Asp i 3 ieee ae : Docsity.com Root cap • Root cap function How might a plant biologist determine the function of a particular plant structure? Docsity.com Zone of maturation _|_ Area of cell f | maturation | _ & Area of cell elongation |_ Apical meristem (Area of cell division) Docsity.com Monocot root, c.s. Docsity.com Dicot root, c.s. Docsity.com Phloem Xylem Endodermis Docsity.com "Soci OF. Botanical MarsPgesipegn Lateral (branch) roots Area of cell maturation Area of cell elongation Apical meristem (Area of cell division) Docsity.com Endodermis Pericycle Docsity.com Docsity.com Root hairs develop from the 1. Root cap 2. Pericycle 3. Stele 4. Zone of maturation 5. Cuticle Docsity.com Regulation of water and mineral uptake is the function of the 1. Root hairs 2. Epidermis 3. Root cap 4. Zone of absorption 5. Endodermis Docsity.com Parasitic roots • Oscula (niyb) of witchweed (Striga sp.) Docsity.com Symbiosis & roots • Mycorrhizae - A mutualistic fungal association with roots Docsity.com Mycorrhizae—Cross-section of a Root with Ectomycorrhizae hyphae cortex yp of root normal roots — mycorrhizal ig sheath epidermis ° A. B. longitudinal section through part of the . root mycorrhizal roots (b) Ectomycorrhizae form a sheath outside the root. (c) The ectomycorrhizae of this pine tree extend for some distance into the soil. Docsity.com Root nodules & legumes Docsity.com Root nodules nitrogen-fixing bacteria within cortex cells of nodules nitrogen-fixing bacteria enter root hair nodule ® Docsity.com Human uses of roots Docsity.com Herbal medications Ginger Mandrake Root 1) aah Docsity.com Valerian extract, derived from the dried rhizomes and roots of the plant, has been used for thousands of years as a folk remedy, tranquilizer and calmative for several disorders such as restlessness, nervousness, insomnia, hysteria, menstrual problems, and as a sedative for "nervous" stomach. Valerian extracts are currently used in scores of compounds and teas in Europe. Valeriana officinalis Docsity.com Licorice (Glycyrrhiza glabra) Docsity.com Phytoremediation Pe eee eure tetas to EH File Edit View Document Comments Tools Advanced Window Help -|a) x : @reb ~ {8 ©2000 Nature America inc. ntp:sbtotech nature.com RESEARCH ARTICLES (ane + f Bookmarks. Phytodetoxification of hazardous organomercurials by genetically engineered plants Signatures ‘Scott P. Bizily', Clayton L. Rugh?, and Richard B. Meagher** 'Deparemene of Generics, University of Georgia, Athens, GA 30602-7223. Deparrmencof Crop wed Soi Scicnces, Michigan Siave Universins East Lansing. Md -AASD4- 1325. "Corresponding auabor (meagherurche aged) Received 13 July 19993 accepted 12 November 1999 Methylmercury is a highly toxic, organic derivative found in mercury-polluted wetlands and coastal sadiments worldwide. Though commanly present at low concentrations in the substrate, methylmercury can biomagnify te concentrations that poison predatory animals and humans. In the interest of develop- ing an in situ detoxification strategy, a model plant system was transformed with bacterial genes (mer for mercuric reductase and merB for organomercurial lyase) for an organic: mercury detoxification path- way. Arabidopsis thaliana plants expressing both genes grow on 50-fold higher methylmercury cencen- trations than wild-type plants and up to 10-fold higher concentrations than plants that express merB alone. An in vivo assay demonstrated that both transgenes are required for plants to detoxify organic mercury by converting it to volatile and much less toxic elemental mercury. bl a7) biotech nature.com G | ni Docsity.com ing Group http://biotech,nature.com ia © 2001 Nature Publishing Group http:/biotech.nature.com RESEARCH ARTICLE Phytodetoxification of TNT by transgenic plants expressing a bacterial nitroreductase Nerissa Hannink'*, Susan J. Rosser't, Christopher E. French’, Amrik Basran’, James A.H. Murray’, Stephen Nicklin’, and Neil C. Bruce™* There is major international concenn over the wide-scale contamination of soil and associated ground water by persistent explosives residues. 2,4.6-Trinitroteluene (TNT) is one of the most recalcitrant and toxic of all the military explosives. The lack of affordable and effective cleanup technologies for explosives contamination requires the development of better processes. Significant effort has recently been directed toward the use of plants to extract and detoxify TNT. To explore the possibility of overcoming the high phytotoxic effects. of TNT. we expressed bacterial nitroreductase in tobacco plants. Nitroreductase catalyzes the reduction of TNT to hydroxyaminedinitrotoluene (HADNT), which is subsequently reduced to aminodinitroteluene derivatives (AONTs). Transgenic plants expressing mitroreductase show a striking increase in ability to tolerate, take up, and detoxify TNT. Our work suggests that expression of nitroreductase (MR) in plants suitable for phytoreme- diation could facilitate the effective cleanup of sites contaminated with high levels of explosives. Docsity.com Roots & agriculture * Root nematodes Docsity.com Root nematode research • Baum lab – Iowa State • Eric Davis - NCSU Docsity.com Root nodules are root modifications for the purpose of 1. Storage of starch 2. Nitrogen fixation 3. Asexual reproduction of the plant 4. Absorbing moisture from the air 5. Providing roots with oxygen in watery habitats Docsity.com Epiphytic plants typically possess 1. Propagative roots 2. Pneumatophores 3. Prop roots 4. Aerial roots 5. Haustoria Docsity.com Stem growth & the shoot apical meristem katt Docsity.com  Anticlinal divisions Leaf primordia Periclinal divisions {c) le model (b) Cell layer model (tunica-corpus model) ; Pearson Education, nc., publishing 2s Benjamin Cummings. Docsity.com Leaf arrangement ¢ Determined in apical meristem HA fits ee an i) MH 3 pL ee Docsity.com Leaf arrangement • Spiral – One leaf per node Docsity.com Leaf arrangement * Opposite — 2 leaves per node Docsity.com Leaf arrangement • Whorled – 3 or more leaves per node Docsity.com Vascular bundle arrangement of roots and stems Roots Stems Monocot Dicot Docsity.com Stem structure {eustele) Transition zone from eustele to protostele e Root structure (protostele) Pearson Education, Inc., publishing as Benjamin Cummings. Docsity.com Dicot stem anatomy Docsity.com Asparagus Monocot stem anatomy Docsity.com Monocot stem anatomy stoma Chlorenchyma —-®aaee Sclerenchyma — Vascular bundles Docsity.com vessel sieve tube companion cell parenchyma cell Asparagus stem vascular bundle Docsity.com In leaf phyllotaxy, one leaf per node is called 1. Alternate 2. Opposite 3. Whorled 4. Unitaxy 5. Monotaxy Docsity.com The attachment point of leaves to a stem is called 1. Phyllotaxy 2. An axillary bud 3. A node 4. The corpus 5. The eustele Docsity.com Which of the following is characteristic of a dicot stem? 1. Scattered vascular bundles 2. Endodermis 3. Pith 4. All of these 5. Both 2 and 3 Docsity.com Leaf characteristics •Phyllotaxy •Complexity •Shapes •Venation •Margins •Surfaces •Leaf characteristics used in plant identification •Leaf key Docsity.com Leaf complexity Compound: mae Compound: palmate pinnate Lanceolate Triangular Cordate (heart- shaped) Simple Compound: doubly pinnate 2004 Pearson Education, Inc., publishing as Benjamin Gummings Docsity.com {c) Margin or Leaf Edge Undulate Serrate Entire Coy 2004 Paarson Education, inc., publishing as Benjamin Gurmmings. (d) Venation Parallel Pinnately net-veined Palmately net-veined Docsity.com Leaf Complexity bipinnate Compound Teal, bipinnate Docsity.com Leaf complexity • What difference do you see in the leaflet pattern? Odd-pinnate Even-pinnate Docsity.com Leaf shape Docsity.com Leaf margins a YUE Revolute Entire Repand Sinuate Lobed Parted Doubly Serrate Crenate Docsity.com Leaf surfaces • Presence (pubescent) or absence (glabrous) of trichomes Docsity.com TYPES OF TRICHOMES 1.UNICELLULAR: Ld a. Papillae b. Water rescicle c. Hair 2. MULTICELLULAR: oO a. Multicellular hair b. Branched SS not shown ¢. Peltate scale d. Glands (many types) Docsity.com Leaf venation is 1. Palmate 2. Parallel 3. Whorled 4. Pinnate 5. Opposite Docsity.com The complexity of this leaf is ____ and the venation is ____. 1. Palmate compound; parallel 2. Palmate compound; palmate 3. Simple; whorled 4. Simple; palmate 5. Palmate compound; whorled Docsity.com Leaf complexity is 1. Even Pinnate compound 2. Opposite 3. Pinnate simple 4. Odd pinnate compound 5. Parallel Docsity.com Leaf anatomy Docsity.com Leaf anatomy - monocots Bundle sheath cell Docsity.com Leaf anatomy - monocots LEAF VENATION MID-VEIN PRESENT VEINS ACROSS SURFACE ah 7 - 7 fe A r =, og ~ “= oy fea pd _ hg. a ae SS) _ >. q * % — i <i ae fe ” oS a @& & ® Docsity.com