Download Transport in Vascular Plants

Chapter 36
Transport in Vascular Plants
Chapter 36
Transport in Vascular Plants
Chapter 36
Transport in Vascular Plants
Physical forces drive the
transport of materials in
plants over a range of
distances.
Chapter 36
Transport in Vascular Plants
Selective permeability:
•Transport proteins allow plants
to maintain an inner environment
that is different from the outer
environment.
Chapter 36
Transport in Vascular Plants
Proton pumps:
•ATP is used to pump H+ ions out
of the cell.
•Transport proteins let them back
in, but only if they bring along
some other, desirable substance.
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Proton pumps:
Chapter 36
Transport in Vascular Plants
Water potential:
•Ψ = Ψs + Ψp
•For pure water open to the
atmosphere, Ψ = 0
Chapter 36
Transport in Vascular Plants
Water potential:
Ψ=0
Ψ=0
Chapter 36
Transport in Vascular Plants
Water potential:
Ψ=0
Ψ=0
Chapter 36
Transport in Vascular Plants
Water potential:
Ψ=0
Ψp = 0
Ψs = -0.23
Ψ = -0.23
Water moves from high Ψ to low Ψ.
Chapter 36
Transport in Vascular Plants
Water potential:
Ψ=0
Ψp = 0.23
Ψs = -0.23
Ψ = 0
Water moves from high Ψ to low Ψ.
Chapter 36
Transport in Vascular Plants
Water potential:
•In biological membranes, water
moves through protein channels
called aquaporins.
Chapter 36
Transport in Vascular Plants
Three major “compartments” of plant cells:
Chapter 36
Transport in Vascular Plants
Three major “compartments” of plant cells:
•Apoplast – cell walls and extracellular space
Chapter 36
Transport in Vascular Plants
Three major “compartments” of plant cells:
•Apoplast – cell walls and extracellular space
•Symplastic – cytoplasm of cells connected by plasmodesma
Chapter 36
Transport in Vascular Plants
Three major “compartments” of plant cells:
•Apoplast – cell walls and extracellular space
•Symplastic – cytoplasm of cells connected by plasmodesma
•Vacuole – surrounded by a membrane called the tonoplast.
Chapter 36
Transport in Vascular Plants
Local transport can be…
Chapter 36
Transport in Vascular Plants
Local transport can be…
•Apoplastic
Chapter 36
Transport in Vascular Plants
Local transport can be…
•Apoplastic
•Symplastic
Chapter 36
Transport in Vascular Plants
phloem
xylem
Bulk transport is
for long distances
Chapter 36
Transport in Vascular Plants
phloem
xylem
Bulk transport is
for long distances
Chapter 36
Transport in Vascular Plants
phloem
xylem
Bulk transport is
for long distances
Chapter 36
Transport in Vascular Plants
Water is pulled, not
pushed up the xylem
phloem
xylem
Bulk transport is
for long distances
Chapter 36
Transport in Vascular Plants
xylem
Transpiration
Chapter 36
Transport in Vascular Plants
Transpiration
xylem
Cohesion
Chapter 36
Transport in Vascular Plants
Transpiration
xylem
Cohesion
Tension
Chapter 36
Transport in Vascular Plants
xylem
Outside air
Ψ = -100 Mpa
Leaf air spaces Ψ = -7 Mpa
Leaf cell walls Ψ = -1 Mpa
Trunk
Ψ = -0.8 Mpa
Root xylem
Soil
Ψ = -0.6 Mpa
Ψ = -0.3 Mpa
Chapter 36
Transport in Vascular Plants
Stomata help regulate
the rate of transpiration
Chapter 36
Transport in Vascular Plants
Stomata help regulate
the rate of transpiration
Chapter 36
Transport in Vascular Plants
•Phloem transports sugars from
sugar sources to sugar “sinks.”
•The flow is pushed along by
osmotic pressure.
Lab 9
Transpiration
Lab 9
Transpiration
Set up four potometers with four conditions.
Lab 9
Transpiration
The first has ordinary room conditions.
Lab 9
Transpiration
The second is under a fan.
Lab 9
Transpiration
The third is under a floodlight.
Lab 9
Transpiration
The fourth is kept in mist.
Lab 9
Transpiration
Measure the water level in the pipette every 3
minutes for 30 minutes.
Lab 9
Transpiration
Which leaves will have the highest rate of
transpiration?
Lab 9
Transpiration
Measure the water level in the pipette every 3
minutes for 30 minutes.
Lab 9
Transpiration
Measure the surface area of the
leaves when you are done
Lab 9
Transpiration
Measure the surface area of the
leaves when you are done
Measure water loss per m2
Lab 9
Transpiration
Measure the surface area of the
leaves when you are done
Measure water loss per m2
Graph your results.
Discussion Questions:
Discussion Questions:
Explain why each of these
conditions causes an increase or
decrease in transpiration compared
with the control.
Discussion Questions:
Explain the role of water potential in
the movement of water from soil
through the plant and into the air.
Discussion Questions:
What is the advantage of closed
stomata to a plant when water is in
short supply? What are the
disadvantages?
Discussion Questions:
Describe several adaptations that
enable plants to reduce water loss
from their leaves. Include both
structural and physiological
adaptations.
Discussion Questions:
Why did you need to calculate leaf
surface area in tabulating your
results?
Discussion Questions:
In the stem cross section shown below,
identify the following cell and tissue
types:
•Parenchyma
•Sclerenchyma
•Collenchyma
•Xylem
•Phloem
•Epidermis
.