PLANT TISSUE

SMAK BPK PENABUR SUKABUMIGRADE XI – SCIENCE CLASSLectures by : Agustina Eka H.,S.SI.

TISSUE ??the smallest basic unit of cells

a group of cells that have similar forms, composition, and function

a unit of several types of tissues that are close to each other and support certain functions

some organs which are coordinate each other and conducting certain functions

cells

tissue

organ

organism

Organ system

Meristematic & Permanent TissueA. Meristematic Tissue Apical meristem Lateral meristem Intercalary meristem

B. Permanent Tissue 1. Simple permanent tissue Parenchyma Collenchyma Sclerenchyma2. Complex permanent tissue Xylem Phloem3. Protective tissue Epidermis Cork (phellem)

Meristematic Tissue

1. have thin cellulose cell walls.

2. The meristematic cells may be

spherical,oval,polygonal or rectangular in

shape.

3. compactly arranged & do not contain any

intercellular space between them.

4. contains dense or abundant cytoplasm & a

single large nucleus.

5. contain few vacuoles or no vacuoles at all

Apical meristems

Are located at the tips of roots and in the buds of shoots

Elongate shoots and roots through primary growth

The root tip is covered by a root cap

Primary meristem

Lateral Meristem

Add thickness to woody plants through secondary growth

Secondary meristem cambium :1) Vascular cambium2) Cork cambium

Vascular cambium

Located between xylem and phloem

Vascularcambium

C X CP

C

XC

XC

PP

PCX

X PC

XX

C C

Types of cell division. An initial can divide transversely to form two cambial initials (C) or radially to form an initial and either a xylem (X) or phloem (P) cell.

(a)

Accumulation of secondary growth. Although shown here as alternately adding xylem and phloem, a cambial initial usuallyproduces much more xylem.

(b)

• An overview of primary and secondary growth

In woody plants, there are lateral meristems that add secondary

growth, increasing the girth of

roots and stems.

Apical meristemsadd primary growth,or growth in length.

Vascularcambium

Corkcambium

Lateralmeristems

Root apicalmeristems

Primary growth in stems

Epidermis

CortexPrimary phloem

Primary xylem

Pith

Secondary growth in stems

PeridermCorkcambium

CortexPrimary phloem

Secondaryphloem

Vascular cambium

Secondaryxylem

Primaryxylem

Pith

Shoot apicalmeristems(in buds)

The corkcambium addssecondarydermal tissue.

The vascularcambium addssecondaryxylem andphloem.

Intercalary meristem

• Intercalary meristem :located between mature tissues, ex : base of nodes in grass stem

• Gramineae or Poaceae(rice, corn, sugar cane)

Epidermis

• Outer layer • Tightly cell • Function : to protect the

underlying cell• Modification : hair, spine,

trichome, stomata, lenticell, root hair, cuticule

Epidermis – stoma, trichomes, & root hairs

http://www.ucd.ie/botany/Steer/hair/roothairs.html

Periderm – cork & parenchyma

TWIG WITH LENTICELS

Parenchyma

• Large cell, thin wall, large vacuolesTypes :1 ) aerenchyma : aquatic plant2) Chlorenchyma : containing chloroplast

Parenchyma

Chollenchyma Function : supporting and strengthening tissue

• Cellulose and pectin thickening in the corner of the cell

Sclerenchyma • Function : organ support• Inactive cell• Cellulose and lignin thickening

Sclereids :Hard and rigidStem cortex, leaf

venetin, root, fruit, and seed

Fiber: hard elongated cells Gymnosperm woody

fiber, bark, leaf fiber, seed fiber

Sclerenchyma

Right-hand illustration modified from: Weier, Stocking & Barbour, 1974, Botany: An

Introduction to Plant Biology, 5th Ed.

SCLERIDS FIBERS

Secretory Cell

• Secrete various substances

Xylem

• Water and mineral transportation• Lignin thickeningConsists of :1) Trachea/vessel element2) Tracheid 3) Xylem fiber4) Xylem parenchyma

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Fig. 35.8

Phloem

• Conduction of nutrition

Consists of :1) Sieve tube2) Companion cell3) Phloem fiber4) Phloem parenchyma