aoa viewers , these ppt have material regarding plant tissue xylem and phloem.

3. Submitted to
Ma’am Sadia shahid
Submitted by
Farwa Tariq
Roll # 95

4. • Definition of vascular tissue
• Explanation about xylem and phloem
• Xylem development types
• Xylem structure
• Primary and secondary xylem
• Primary and secondary phloem
• Relation between primary vs secondary xylem and phloem
CONTENT

5. ADVANCED ANATOMY
OF PLANTS
VASCULAR TISSUE AND ITS RELATION
BETWEEN PRIMARY AND SECONDARY TISSUE

6. VASCULAR TISSUE
• Vascular tissue is complex tissue formed from one or more type of cells and
present in vascular plants and product of photosynthesis transport.
• Primary components of vascular tissues are xylem and phloem.
• These two tissues transport mineral and nutrients throughout the plant from
root to leaves.
• There are also to meristem associated with vascular tissue the vascular
cambium and cork cambium.

7. XYLEM
• Xylem is responsible for the transport of water and dissolved
ions minerals throughout the plant from root to upward .
• Every cell in plan need water and mineral to survive.
• Water is absorbed inside the root and it develops positive
pressure inside the plants.
• As water evaporate from the leave the process of
transpiration pulls water into the leaves.
• In this way xylem act as straw, allow water to plant.

8. Cross section of xylem tissue

9. STRUCTURE OF XYLEM
• Xylem is made of several type of cells.
• Tracheids
• Tracheids are long cells that transport xylem sap and provide
structural support. they are tapering from both ends.
• Vessel elements.
• These are shorter than tracheids and help in conducting water
they have perforation plates that connect each vessel to one
another and form long pipe

10. Xylem parenchyma
Xylem also contains parenchyma a tissue that makes up most of soft parts of the
plant, long fiber that provide support.

11. XYLEM DEVELOPMENT TYPES
• The first xylem that develops in a growing plant is called
protoxylem, and it contains narrow vessel because plant is
yet small. Metaxylem develops later and has large vessels
and cells.

12. There are four ways of arrangement of protoxylem and metaxylem in plants.
• centarch
• There is one vascular strand and protoxylem is in the center and metaxylem
surrounded it.This formation is present in extinct plant.
• Exarch
• Arrangement in which the protoxylem is present at peripheral and metaxylem is
directed toward center in root of vascular plants.
• Endarch
• Occurrence of protoxylem towards the center and metaxylem towards the peripheral
in the stem of seed plants

13. Mesarch
Xylem develop in multiple strand and each strand develop from its middle
both toward the center of stem and in opposite direction toward peripheral.
Xylem in leaves and ferns develop by this way.

14. PHLOEM
• Phloem is consisting of mostly sieve tube cells and companion cells.
• These cells helps in transport product of photosynthesis sugar and nutrients
from leaves to roots.
• Sieve tube and companions' cells of phloem are living.
• Companions cells having nucleus and actively transport sugar into and out
of the sieve-tube.

15. Elongated cells placed end to end to form long tube .Their end walls have
pores which form sieve plates.
The main function of the sieve tube is to carry carbohydrates
Sieve-tube elements

16. ❑Phloem parenchyma
• They are also called transfer cells and border parenchyma cells and it is
present near the finest branches and end terminal of sieve tube in leaf
veinlets where they involved in transport of food.
• Phloem Fiber
• Phloem fiber are thin delicate long and make up the soft fibers, e.g (flax
and hemp)

17. PRIMARY AND SECONDARY
VASCULAR TISSUE
• Primary
vascular tissue
It is derived from
procambium, itself
produced by the apical
meristem, and by the
primary thickening
meristem in a few
monocot.
• Secondary
vascular tissue
• It is derived from vascular
cambium in dicot, form
and the secondary
thickening meristem in a
few monocot.

18. ✓ Xylem types on the bases of origin of development
✓ Xylem have two types on the basis of origin
✓ Primary Xylem derived or formed from procambium. It consist of protoxylem
and metaxylem based on development
✓ Protoxylem and metaxylem.

19. Protoxylem
✓ early formed part of
primary xylem
✓ It mature before the
elongation of plant organs
✓ Metaxylem later formed
and large in size .
Metaxylem
✓ It is later formed part of
primary xylem.
✓ Mature after the attaining
the size of plants organs
✓ Metaxylem cells are
comparatively large and it
contain low amount of
parenchyma cells.

20. • Cell size are comparatively
small
• Contain large amount of
xylem parenchyma cells.
• Xylem fibers are absent in
it.
• Lumen in narrow
• Lignification is in-extensive.
• Fibers are present and
lumen is wide, and
lignification is extensive.
• Vessels exhibit scalariform
reticulate and pitted
thickening more efficient in
conducting water and
found towards inside stem.

21. • Vessels having annular and
spiral thickenings.
• Less efficient in
conducting water
• Founds toward outside in
the stem...
• In roots present in the
center.

22. SECONDARY XYLEM
• Secondary xylem develop major part of stem or mature
root and its formation increase plant girth and plant expand
and it build a new ring around already present primary
xylem tissue.
• After its formation, the primary xylem loss its function
conductance of water and forming a hard skeleton that
support the plants.
• So the main plant body or trunk and previous branches of
large tree the out layer, of secondary xylem serve as water
conduction and inner part of primary xylem dead .

23. • In temperate or cold climate growth rings are used to determine age of
plants by counting the annual xylem rings formed at the base of trunk.
Water conducting xylem tissue of root

24. PRIMARY PHLOEM
• Primary phloem is formed by the apical meristems by
which new cells formed of root and shoots.
• It may be protophloem which is formed earlier, and
its cells mature before cell elongation.
• Protophloem having sieve tube which are unable to
extent with elongated tissue and it is diminish with
the age of plant.

25. Meta-phloem which is formed later, and its cells mature after elongation
Meta-phloem is not damaged or destroy and perform function throughout
the plant's life such as palm and later it is replaced by secondary phloem in
plants that have cambium.

26. SECONDARY PHLOEM
• Tissue produced outside of the vascular cambium is complex tissue that include
axial and a ray system.
• Secondary phloem having conducting cells, sieve cells in conifers and sieve tube
in angiosperm.
• Fibers are very common in the secondary phloem.
• Pattern of fiber formation in cambium used to identify secondary phloem and
bark tissue.
• Phloem parenchyma occurs in axial system as well as companion cells in
angiosperms and albuminous cells in conifers.

27. RELATION BETWEEN PRIMARY AND
SECONDARY VASCULAR TISSUE.
• The primary meristem shoot apical meristem (SAM) and
root apical meristem (RAM) produce primary vascular
bundle which have primary xylem and primary phloem.
• Herbaceous plants lack cambium and cannot not develop
further, and they are called closed vascular bundle.

28. • Open vascular bundle.
• Vascular bundle having cambium in their center.
• They convert primary state to secondary state under the activation of
vascular cambium which generate secondary xylem and secondary phloem