PHA611 Pharmaceutical Botany with Taxonomy Lecture Notes PDF

PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) [TRANS] I. II. III. IV. V. OUTLINE Major Functions Organization of Root Systems External Structure of Taproot System a. Structure of Individual Roots b. Other Functions of Root Cap Diffusi...

PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) [TRANS] I. II. III. IV. V. OUTLINE Major Functions Organization of Root Systems External Structure of Taproot System a. Structure of Individual Roots b. Other Functions of Root Cap Diffusion Paths in Roots Modified Roots Radicle ● ● ● Origin of tap root Growing tip of the hypocotyl Part of seed where root develops ● ● ● ● Upper axis- epicotyl Lower axis - hypocotyl Growing tip of hypocotyl - radicle Radicle is the first to grow and will become taproot if it continues to grow ● Germinating seed showing the emergence of primary root from the radicle MAJOR FUNCTIONS ● ● ● Anchoring the plant firmly to a substrate o Usual substrate - soil Absorbs water and minerals Production of hormones o Hormones - Regulate the process, growth, and development of the plant o Reproduced by the root system ORGANIZATION OF ROOT SYSTEM ● ● ● Types of root systems: 1. Taproot 2. Fibrous or diffuse 3. Adventitious Example of herbaceous taproot - carrot Ex. of woody dicot- trees Taproot ● ● Develops from an embryonic root called radicle After germination, it grows to become the largest root in the system Fibrous ● ● ● Similarly sized roots Arise because the radicle dies during or immediately after germination Usually seen in monocot plants ○ Slender, finer, and fibrous - fibrous system ○ Fibrous root system are annual plants which are short lived BORILLO, CABARDO, CRUZ K, PEÑAS 1 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) ● Ex. Onion or garlic EXTERNAL STRUCTURE OF TAPROOT SYSTEM ● Parts: Grass’ roots Adventitious ● ● Do not arise from pre-existing roots, but arise from other parts of plants ○ May be from stem or the lateral branches Increase absorptive and transport capacities of the root system ○ Brace root - arise from main trunk stem ○ Prop root - arise from lateral branches of main stem o o o o Tap root - single prominent root Lateral - small and arise from the taproot Root hairs - arise from epidermis, a single-celled extension that increases absorptive area, no line of demarcation in the epidermal cells Root tips/apical meristem - the growing protection protected by the root tap and root tip STRUCTURE OF INDIVIDUAL ROOTS Brace root of corn Prop root of Banyan which arise from main tree - mangrove trunk/stem of Zea mays ● Balete tree- both brace and prop root are present BORILLO, CABARDO, CRUZ K, PEÑAS 2 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) Slime/Mucigel ● lubricate the passage of roots through the soil. Three Primary meristem zones of Apical Meristem Type of Permanent Tissue PROTODERM Epidermal Tissue GROUND MERISTEM Ground Tissue or Chyma group PROCAMBIUM Vascular Tissue xylem and phloem Quiescent Center ● This is the mitotically inactive region of the root apical meristem. ● This acts as a reserve of healthy cells. ● Resistant to toxic substances and radiations. Other functions of Root Cap ● Gravity-sensing (Geotropism) - response of root toward pull of gravity ● Lubrication Meristem Protection ● Carbon Flow ● Rhizosphere Interaction - interaction with microorganism Anatomy of Young Dicot Root Parts of Individual Roots Root Cap ● A thimble-like mass of parenchyma cells that covers the root and secretes mucigel. BORILLO, CABARDO, CRUZ K, PEÑAS 3 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) Three Regions of Permanent Tissues ● Dermal (Epidermis) ● Cortex ● Stele/Vascular Cylinder Variations in the Number of Xylem Strands in Roots Endodermis ● This controls the passage of minerals across the vascular tissues. ○ has thick-walled cells (encrusted w/ suberin & lignin) ○ has passage cells (thin-walled) Casparian Strips ● These are bands of lignin and suberin on the radial walls (top, bottom and side walls) causing the cell walls to be waterproof. Vascular Cylinder/Stele Region No. of xylem poles How many xylem poles 3 (triarch) 4 (tetrarch) 5 (pentarch) many polyarch Present in what type of plant dicot dicot dicot monocot (w/ pith parenchy ma) What type of stele is present? protostele cyconost ele protostele cyconost ele Seconda ry Growth? Yes Yes Yes No BORILLO, CABARDO, CRUZ K, PEÑAS 4 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) Diffusion Paths in Roots APOPLAST ● ● ● SYMPLAST Water and mineral ● diffuses only through walls in intercellular spaces Cell hair Simple diffusion ● ● The material passes through a plasma membrane and enters the protoplasm Across cell membrane Osmosis Monocot Root Origin and Development of Lateral Roots Lateral root ● initiated by cell divisions in the pericycle. BORILLO, CABARDO, CRUZ K, PEÑAS 5 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) ● as it pushes outward, it destroys the cells of the cortex and epidermis that lie in its path, ultimately destroying the endodermis. Old Dicot Root 2. Buttresses - expanded roots for great support, upper side grows faster than the lower side Two distinct regions: Region of secondary Region vascular tissues which layers: include the: of periderm secondary phloem aka Inner bark phellem or cork vascular cambium phellogen or cork cambium secondary xylem aka wood phelloderm or secondary parenchyma 3. Velamen and chlorophyllous roots of orchids MODIFIED ROOTS 1. Prop roots - for additional support and absorption BORILLO, CABARDO, CRUZ K, PEÑAS 6 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) 6. Pneumatophores mangrove for aeration breathing roots of 4. Movement - Contractile roots of bulbs like onions, gladiolus, garlic 7. Enlarged fleshy tap root - carrots, tugue, radish, turnips ube, 5. Parasitic (haustorial roots) for absorption BORILLO, CABARDO, CRUZ K, PEÑAS 7 PHA611: PHARMACEUTICAL BOTANY WITH TAXONOMY LECTURE: UNIVERSITY OF SANTO TOMAS - FACULTY OF PHARMACY (1A-PH) 8. Root nodules for nitrogen fixation Converts N2 into NO3. Species of bacteria: Rhizobium leguminosarum 10. Spiny roots for protection 9. Mycorrhizae - association between a soil fungus and roots. a. Two Types i. Ectomycorrhizae - Fungi found in the surface of the roots ii. Endomycorrhizae - Fungi found in the inside of the roots (region of the cortex) BORILLO, CABARDO, CRUZ K, PEÑAS 8