Mechanism of water transport and also pathway of water across the root and plant.

1. MECHANISM OF H2O TRANSPORT AND
PATHWAY OF H2O ACROSS THE ROOT AND
PLANT
Presented to:
MAM SUMMERA JAHAN
Presented by:
MAHREEN IJAZ
18441506-066

2. WHY DO PLANTS REQUIRE WATER?

3.  Actually plants need water for manufacturing food during Photosynthesis.

4. In which conditions plants need water?
TRANSPIRATION
TRANSPORT OF WATER
ABSORPTION

5. Mechanism of H2O Transport
 Water is absorbed in the region of Root hair
 Dilute soil solution have high water potential
 Root hair have low water potential as compare to Dilute soil solution
 Water will move from Soil to Roots by “Osmosis” and “Passive transport”
OSMOSIS & PASSIVE TRANSPORT
 Movement of water through a from a region of high concentration to a region of low
concentration, for equalize the concentrations of the water.
 Osmosis is passive transport, it does not require energy to be applied.

6.  Water from the cell
 Root hair & then in the epidermal cells
 Water potential gradient develops between the adjacent cells in the root
 Facilitate the movement of water in the root

7. Pathway of water across the roots
 Dilute soil solution have high water potential as compare to root hair so water will move from
soil to root.
ROOT HAIRS: Root hairs re extremely thin wall. Water can easily move inside
the root hair
 After receiving the water from soil, root hair have high water potential as compare to epidermal
cells so, it gives water to epidermal cells.
EPIDERMAL CELLS: They are flat cells and from this numerous root hairs
grow in soil. It protects against:
 Water loss,
 Regulates gas exchange,
 Secretes metabolic compounds,
 And (especially in roots) absorbs water and mineral nutrients.

8. Pathway of water across the roots
 Then epidermal cells have high water potential and cortex have low so, epidermal cells
gave water to cortex.
CORTEX: They are thick walled cell and numerous air spaces are present in cortex .The
functions of cortex is:
 Storage of photosynthetic products.
 It also help in uptake of water and minerals.
 So cortex have high water potential and it gives water to endodermal cells because
endodermal cells have low water potential.
ENDODERMAL CELLS: Thick walled cells and they have Caesarean strips. It helps:
 Regulate the movement of water
 Ions and hormones into and out of the vascular system.

9. Pathway of water across the roots
 After receiving water from cortex, endodermal cells have high water potential so it gives water to pericycle
cells.
PERICYCLE CELLS: Layer of living cells. The main function of the pericycle cells of vascular plants is to:
 Provide support
 Structure,
 And protection for the plant
 After this. pericycle cells have high water potential so it gives water to xylem cells so xylem cells have water
and then water can move on the upper parts of plants.
XYLEM CELLS: Center of the roots occupied by xylem cells and they have many round .small phloem. The
basic function of xylem is:
 Transport water from roots to stems and leaves,
 But it also transports nutrients.

10. Pathway of water across the roots
 Dilute soil solution(high water potential & low solute potential)
 Root hair
 Epidermal cells
 Cortex
 Endodermal cells
 Pericycle cells
 Xylem cells

13. Transport of water in plants

14. Pathway of water across the root
 Water can move by Appoplast, Symplast & Vacuolar pathway in the root
 But in the Endodermal cells due to presence of Casparian strips appoplast can not operate
because it is impermeable to water
 In the endodermal cells of roots water can move by
 Symplast pathway
 By vacuolar pathway
 Transfusion cells

15. Benefits of endodermal cells
 Filtration unit of the cell
 They can filter the
 Toxic substances
 Micro-organisms
 Pathogens
 Heavy metals
 Reduce backflow of water

16. Movement of water across the plant
 When xylem of the root have high water potential, that is why it gives water to
xylem of the stem.
 After receiving water from xylem of the stem, it gives water to Xylem of the cell.
 Then, Xylem of the cell transpire water into mesophyll cells of the leaves and from
the stomata water can transpire into the AIR.
 From this movement water can move across the plant.

17. Movement of water across the plant
Water will transpire into air
Deficiency of H2O in the mesophyll cells and then stomata
Xylem of the cell
Xylem of the stem
Xylem of the root

18. THANK YOU

19. ANY QUESTIONS??