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

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

REFFERENCE

•WWW.ITUTOR.COM

• GEONYZL, (2011)

THANK YOU