plant tissue

1. PLANT TISSUE
Presented by:
S. Konmei Mukholee
M.Sc. 1st semester
Department of Life Science
Bangalore University
Under the Guidance of:
Dr . Prabhu B.M.

2. PLANT TISSUES
Plants perform functions which are different
from animals and also their structure is different ,
hence they have tissues which are different from
animals.
They are further classified into many sub
categories which is shown in the table below:

4. MERISTEMATIC TISSUE
 Meristematic tissue are the growth tissue and found in
those region of plant that grow continuously.
 Cells of meristems divide continuously and help in
increasing the length girth of the plant body.
 According to their position in plant, meristems are apical,
lateral and intercalary.
Functions: The main function of meristems is to continuously
form a number of new cells.

5. CHARACTERISTICS OF MERISTEMATIC TISSUE
• The cells of meristematic tissue are
similar in structure and have thin
cellulose cell walls.
• The cells may be round , oval,
polygonal or rectangular in shape.
• They are compact, having no
intercellular space.
• There is a large nucleus and
abundant cytoplasm.
• The protoplasm contains very few
or no vacuoles at all.
Meristematic tissue as seen in cross
section

6. TYPES OF MERISTEMATIC TISSUE
1. Apical meristems
2. Intercalary meristems
3. Lateral meristems

7. APICAL MERISTEM
• These are situated at the
growing tip of the dicot stems
and roots i.e. at shoot apex and
root apex. Apical meristems are
also found in the apices of the
leaves.
• In plants belonging to the
MONOCOT class, apical
meristems are located ONLY in
the root tips.
• As cells in apical meristems divide
and elongate, shoot tips and root tips
grow longer. This increase in length is
called primary growth.
Root cap
Apical Meristem in a Root Tip

8. • These are located at the base
of the nodes, internodes,
leaves etc.
• They are also present in
between the permanent
tissue.
• It produce an increase of
length of organ.
• E.g...stems of grasses or other
monocots.
INTERCALARY MERISTEMS

9. INTERCALARY MERISTEMS
Monocots, like grasses, have intercalary meristems which allow the leaves to
grow back after mowing.

10. phloem
Vascular cambium
Xylem(wood)
Cork(bark)
Cork cambium
LATERAL MERISTEMS
Cross section of dicot woody stem

11. PERMANENT TISSUE
• These tissues arise from the meristematic
tissue.
• They are non-meristematics /consisting of
only one kind of cells.
• These tissues may be living or dead.
Permanent tissue is classified into two types:
1. Simple permanent tissue.
2. Complex permanent tissue.

12. SIMPLE PERMANENT TISSUE
These tissue are composed of cells which are
structurally and functionally similar. Thus, this are
made of one types of cells.
Three categories of simple permanent tissue:
1. Pollenchyma
2. Collenchyma
3. sclerenchyma.

13.  The cells are living.
 The cells are thin walled.
 There may or may not be
intercellular spaces.
 They are the most
unspecialized cells.
 No depositions are seen, the
cell wall consists only of
cellulose.
 There is a prominent
nucleus, cytoplasm &
vacuoles
PARENCHYMA
Parenchyma
Intercellular spaces

14. Storage parenchyma : The cells
enlarge to store nutrients & water.
Aerenchyma : Air cavities are
present in the parenchyma tissue to
provide buoyancy to the aquatic
plants.
Chlorenchyma : These parenchyma
cells have presence of chlorophyll &
hence can perform the function of
photosynthesis.
Parenchyma tissue is found generally
in all parts of the plant body. It
forms the Ground tissue in leaves,
stem, roots & fruits etc.
.
AERENCHYMA
CHLORENCHYMA
There are some special types of parenchyma tissues :

15. 1. Parenchyma serves as packing tissue.
2. By providing turgidity , they provide mechanical
strength.
3. Parenchyma serves as a food storage tissue.
4. Transport of material occur through cell or cell
walls of parenchyma cells.
5. Parenchyma cells are metabolically active.
FUNCTION OF PARENCHYMA

16. COLLENCHYMA
They are located below the
epidermis of dicotyledons
stem and petiole.
These cells also occur in the
mid rib of the dicot leaves
The cells are living.
Less Intercellular space
present.
They contain few chloroplast.

17. 1. Collenchyma is a mechanical tissue and protective in
function.
2. Cells are living i.e. non lignified.
3. They contain few chloroplasts.
FUNCTIONS OF COLLENCHYMA

18. SCLERENCHYMA
 Dead cells with no protoplasm.
 The walls of cells greatly thickened
& lignified.
 Due to excessive thickening of the
wall of sclerenchyma cells, its cell
cavity or lumen becomes nearly
absent.
 The cells of are closely packed.
 No intercellular spaces.
No intercellular space
They are found in Stems, roots, veins
of leaves, hard covering of seeds &
nuts.
Sclerenchyma

19. There are two types of sclerenchyma cells
Fibres
• Fibres are long, thickened cells with
thick lignified walls and narrow lumens.
• Their walls have simple pits.
• Elongated sclerenchyma cells usually
with pointed end.
• fibres are found in xylem and phloem
and form bundles caps in dicotyledons
stems.
They provide mechanical strength and
protection to the non growing regions.
Sclereids:
• Sclereids shorter and fatter than
fibres & have heavily lignified cell
walls.
• They are commonly found in the
cortex and pith of gymnosperms and
dicotyledons.
Sclereids may occur in isolation in the
cortex, pith, xylem and phloem or may
occur in groups in the testa of seeds eg.
shell of walnut.
FIBRES SCLEREIDS
parenchyma

20. The complex tissues consist of more than one type of cells. All
these co-ordinate to perform a common function.Complex tissues
transport water,mineral salts(nutrients) & food material to various
parts of plant body.Complex tissues are of following two types :
I.Xylem or wood
II.Phloem or bast
Xylem & phloem are both conducting tissues & also known as
vascular tissues; together both of them constitute vascular
bundles.
COMPLEX PERMANENT TISSUE

21.  They are found in the vascular bundles of
roots, stems and leaves
 xylem is a vascular & mechanical tissue.
 Xylem is composed of cells of four
different types; vessels, tracheids
xylem(parenchyma cells) and fibres.
 Vessels and tracheids are very long tube-
like structures formed by a row of cells
placed end to end.
Functions-
i. The main function of xylem is to carry water &
minerals salts upward from the root to different parts
of shoots.
ii. Since walls of tracheids, vessels & sclerenchyma of
xylem are lignified, they give mechanical strength to
the plant body.
XYLEM

22. PHLOEM
 Like xylem, it contains tubes but
has no mechanical function.
 phloem is composed of following
four elements or
cells.1.sievetubes elements;
2.companion cells;3.phloem
parenchyma& 4.phloem fibres.
 Except for phloem fibres, phloem
cells are living cells.
Functions:
phloem transport
photosynthetically prepared food
materials from the leaves to the
storage organs & later from
storage organs to the growing
regions of the plant body.
Companion cell
nucleus
Sieve plate
sieve plate
PHLOEM
Sieve tube
element
plasmodesmata

23. • It is usually present in the outermost
layer of the plant body such as leaves,
flowers, stem & roots.
• Epidermis is one cell thick & is covered
with cuticle.
• Cells of epidermis are elongated &
flattened & do not contain any
intercellular space between them
EPIDERMIS
Functions
The main function of epidermis is to
protect the plant from desiccation &
infection. In fact, cuticle of epidermis
helps to reduce water loss by evaporation
from the plant surface as well as helping
in preventing the entry of pathogens. epidermis

24. REFERENCES
 An Introduction to Plant Biology, Mauseth, James D. 2003. Botany: 3rd
Edition. Jones and Bartlett, Sudbury, MA.
 “A TEXTBOOK OF BOTANY” Author Bhattacharya, Hait, Gosh volume II
published 2007
 “ PLANT ANATOMY” Author B.P. PANDEY, S . CHAND.
 “PLANT ANATOMY” Author KATHERINE ESAU . PUBLISHED by John wiley
and sons 1953.