Post on 20-May-2015
PLANT TISSUES
BY LA NDLOVU
201208082
TISSUES
A GROUP OF CLOSELY ASSOCIATED CELLS THAT PERFORM RELATED FUNCTIONS AND ARE SIMILAR IN STRUCTURE.
Shoot System
Root System
Root system
- anchors the plant
- penetrates the soil and absorbs water and minerals
- stores food
Shoot system
- produces sugars by photosynthesis
- carries out reproduction
Shoot and Root Systems
water & minerals
sugar
SHOOT SYSTEM
ROOT SYSTEM
Shoot and root systems are interdependent
PLANT TISSUE SYSTEMS
VASCULAR TISSUES
GROUND TISSUES
SHOOT SYSTEM
ROOT SYSTEM
EPIDERMIS
• Ground tissue system
• Vascular tissue system
• Dermal tissue system
PLANT TISSUES
TISSUES IN PLANTS THAT DIVIDE THROUGHOUT THEIR LIFE.
PLANT TISSUES CAN BE CLASSIFIED AS: GROWING OR MERISTEMATIC TISSUE PERMANENT TISSUE
Meristematic tissue
Permanent tissue
MERISTEMATIC TISSUES
The growth of plants occurs in certain specific regions.
This is because the dividing tissue, Known as meristematic tissue Composed of actively dividing ceIIs,
responsible for the production of ceIIs. Capacity for division is restricted to certain parts of the plant body called meristems
Which are active throughout the life of the plant body.
MERISTEMATIC TISSUES
MERISTEMATIC TISSUES
KINDS OF MERISTEMS:
• APICAL MERISTEMS – FOUND AT THE TIP OF STEMS & ROOTS
• LATERAL MERISTEMS – A.K.A. CAMBIA
- FOUND ALONG THE SIDES OF ROOTS & STEMS
- INCREASE WIDTH OR DIAMETER OF STEMS & ROOTS
- TYPES: 1. VASCULAR CAMBIUM 2. CORK CAMBIUM
• INTERCALLARY MERISTEMS – FOUND AT THE BASES OF YOUNG LEAVES & INTERNODES
- RESPONSIBLE FOR FURTHER LENGTHENING OF
STEMS & LEAVES
PERMANENT TISSUES
Tissues that attained their mature form and perform pacific functions.
They stop dividing
Types:• Simple permanent tissues• Complex permanent tissues
DERMAL / SURFACE TISSUE
SIMPLE PERMANENT TISSUES
- CONSIST ONLY OF ONE KIND OF CELLS
A. DERMAL / SURFACE TISSUE
- EXTERNAL TISSUES
- FORMS PROTECTIVE COVERING OF THE PLANT BODY
A. EPIDERMIS
B. PERIDERM
PERMANENT TISSUES
• EPIDERMIS
- THE OUTERMOST LAYER OF THE PRIMARY PLANT BODY - COVERS THE LEAVES, FLORAL PARTS, FRUITS, SEEDS, TEMS AND ROOTS
- GENERALLY ONLY ONE LAYER THICK WITH CUTICLE
- COMPOSED MOSTLY OF UNSPECIALIZED CELLS, EITHER
PARENCHYMA AND/OR SCLERENCHYMA
- CONTAINS TRICHOMES, STOMATA, BUIIIFORM CEIIS (IN GRASSES)
STRUCTURE OF EPIDERMIS
• STOMATA - PORES FOR GAS EXCHANGE - PRESENT ON ONE OR BOTH SURFACES OF
LEAVES.
Stomata
CUTICLE – LINES THE OUTER WAII OF THE EPIDERMAL CEIIS
- MADE UP OF WAXY MATERIAL THAT PROTECTS PLANTS FROM DESICCATION
Cuticle
Cuticle
Layer of the leaf
Trichomes
Trichomes – outgrowths of epidermal ceIIs
• PERIDERM (BARK) IS THE OUTERMOST LAYER OF
STEMS AND ROOTS OF WOODY PLANTS SUCH AS TREES.
Periderm (Bark)
GROUND TISSUES
1. PARENCHYMA
- ARE THE GENERAL PURPOSE CEIIS OF PLANTS
- CELLS ARE ROUNDED IN SHAPE & HAVE UNIFORMLY THIN WALLS FOUND IN ALL PARTS OF THE PLANTS.
- LIVING AT MATURITY, HAVE LARGE VACUOLES
- LOCATION IEAF, STEM (PITH), ROOTS, FRUITS
FUNCTIONS:
*BASIC METABOLIC FUNCTION (RESPIRATION, PHOTOSYNTHESIS (CHIORENCHYMA IN LEAF) & PROTEIN SYNTHESIS)
*STORAGE (POTATOES, FRUITS, & SEEDS)*WOUND HEALING AND REGENERATION
PARENCHYMA
COLLENCHYMA
SCLERENCHYMA
Right-hand illustration modified from: Weier, Stocking & Barbour, 1974, Botany: An
Introduction to Plant Biology, 5th Ed.
SCLERIDS FIBERS
VASCULAR TISSUES
SPECIALIZED FOR LONG-DISTANCE TRANSPORT OF WATER AND DISSOLVED SUBSTANCES.
CONTAIN TRANSFER CEIIS, FIBERS IN ADDITION TO
PARENCHYMA AND CONDUCTING CEIIS.
LOCATION, THE VEINS IN IEAVES
TYPES:
1. XYLEM
2. PHLOEM
Complex Permanent Tissues
XYLEM
GW XYIOS W/C MEANS “WOOD” TRANSPORTS WATER AND DISSOLVED NUTRIENTS FROM THE ROOTS TO AII PARTS OF A PLANT.
DIRECTION OF TRANSPORT IS UPWARD.
THERE ATE TWO TYPES
• PRIMARY XYLEM – DIFFERENTIATES FROM PROCAMBIUM IN THE APICAL MERISTEM & OCCURS THROUGHOUT THE PRIMARY PLANT BODY.
• SECONDARY XYLEM – DIFFERENTIATES FROM VASCULAR CAMBIUM & IS COMMONLY CALLED WOOD.
Xylem
• XYLARY ELEMENTS – THE CONDUCTING CELLS IN XYLEM
- 2 KINDS OF XYLARY ELEMENTS:
• TRACHEIDS – THE ONLY WATER CONDUCTING CELLS IN MOST WOODY, NON FLOWERING PLANTS.
• VESSEL ELEMENTS – OCCUR IN SEVERAL GROUPS OF PLANTS, INCLUDING ANGIOSPERM.
- BOTH ARE ELONGATED, DEAD AT MATURITY, LIGNIFIED SECONDARY CELL WALLS.
Xylem
Tracheids Vessel elements
PHIOEM
- GREEK WORD PHLOIOS MEANING, “BARK”
- TRANSPORTS DISSOLVED ORGANIC / FOOD MATERIALS FROM THE IEAVES TO THE DIFFERENT PARTS OF THE PLANT
- GLUCOSE IN PHLOEM MOVES IN AII DIRECTIONS
TYPES
1. PRIMARY PHLOEM – DIFFERENTIATE FROM PROCAMBIUM AND EXTENDS THROUGHOUT THE PRIMARY BODY OF THE PLANT.
2. SECONDARY PHLOEM – DIFFERENTIATES FROM THE VASCULAR CAMBIUM AND CONSTITUTE THE INNER LAYER OF THE BARK.
PhIoem
SIEVE TUBE ELEMENTS MAIN CONDUCTING CEIIS OF PHLOEM
ELONGATED AND NON-NUCLEATED
UNIFORMLY THIN WALLED WITH THE END WALLS
PERFORATED TO FROM THE SIEVE PLATE. SIEVE TUBE ELEMENT ARE ATTACHED END TO
END TO FORM THE SIEVE TUBE.
PhIoem
PhIoem
SIMPLE TISSUES – CONSISTING OF ONE CELL
TYPE• PARENCHYMA – THIN WALLED & ALIVE AT MATURITY;
OFTEN MULTIFACETED.• COLLENCHYMA – THICK WALLED & ALIVE AT MATURITY• SCLERENCHYMA – THICK WALLED AND DEAD AT
MATURITY• SCLERIDS OR STONE CELLS – CELLS AS LONG AS THEY ARE
WIDE• FIBERS – CELLS LONGER THAN THEY ARE WIDE
• EPIDERMIS – ALIVE AT MATURITY• TRICHOMES – “PUBESCENCE” OR HAIRS ON EPIDERMIS• ROOT HAIRS – TUBULAR EXTENSIONS OF EPIDERMAL CELLS
EPIDERMIS – STOMA, TRICHOMES, & ROOT HAIRS
http://www.ucd.ie/botany/Steer/hair/roothairs.html
COMPLEX TISSUE
• XYLEM – WATER CONDUCTING TISSUE; PARENCHYMA, FIBERS, VESSELS AND/OR TRACHEIDS, AND RAY CELLS.
• PHLOEM FOOD CONDUCTING TISSUE; SIEVE-TUBE MEMBERS (NO NUCLEUS AT MATURITY, CYTOPLASM PRESENT), COMPANION CELLS, FIBERS, PARENCHYMA, AND RAY CELLS. IN FLOWERING PLANTS, SIEVE-TUBE MEMBERS AND COMPANION CELLS ARISE FROM THE SAME MOTHER CELL.
• PERIDERM – PROTECTIVE COVERING; COMPOSED OF CORK AND PARENCHYMA.
• .
XYLEM
PHLOEM
VASCULAR BUNDLES WITH XYLEM & PHLOEM
Maize or Corn – vein in cross section
Alfalfa – vein in cross section
THANK YOU