1. Transport In Plants

3. Water Potential
The physical property predicting the direction in which water will flow
____________________
Pressure
water moves from high water potential to low water potential
Solute Concentration

5. Water Potential (a) Left Side Right Side Water moves to the right
Pure Water = 0 Water Potential
Right Side
Negative Water Potential
0 pressure
- solute (has solutes)
Water moves to the right

6. Water Potential (b) Left Side Right Side Water is at equilibrium
Pure Water = 0 Water Potential
Right Side
0 Water Potential
+ pressure equal to solute conc.
- solute (has solutes)
Water is at equilibrium

7. Water Potential (c) Left Side Right Side Water moves to the left
Pure Water = 0 Water Potential
Right Side
Positive Water Potential
+ pressure more than solute conc.
- solute (has solutes)
Water moves to the left

8. Water Potential (d) Left Side Right Side Water moves to the left
Pure Water and Negative Tension
Right Side
Negative Water Potential
0 pressure
- solute (has solutes)
Water moves to the left

9. Transport of Xylem Sap Pushing Xylem Guttation Root Pressure
caused by active pumping of minerals into xylem
_____________: accumulation of water
Guttation

10. Transport of Xylem Sap ______________ Pulling Xylem Transpiration
evaporative loss of H2O from a plant through the stomata

12. Transport of Xylem Sap

15. The Control of Transpiration
______________
turgid - open
flaccid - closed
Potassium Ions
active transport of H+ out of cell causes K+ to move in
Guard Cells

16. Stomata Open during the day / Closed at night
first light (blue light receptor)
depletion of Carbon Dioxide
internal clock (circadian rhythms)

17. Reducing Transpiration
Small, thick leaves
Thick cuticle
Stomata are recessed
Lose their leaves
C4 or CAM plants

18. Translocation of Phloem Sap

19. Translocation of Phloem
Phloem Sap
30% sucrose, minerals, amino acids, hormones
Transported in sieve-tube members
____________– leaves, tuber or bulbs
Sugar sink – growing roots, shoots, fruits
Sugar source

20. Pressure Flow and Translocation
Pressure is high
Pressure is low
Xylem recycles water
Allows Phloem sap to flow from source to sink C B

21. Plant Nutrition

22. Uptake of Nutrients Hydroponic
_______________ cultures used to determine which chemical elements are essential.
17 essential elements needed by all plants

24. Soil Develops from weathered rocks Anchors plants Provides water
Provides dissolved minerals

25. Soil Texture Pertains to sizes of soil particles
includes the following:
sands ( mm)
silt ( mm)
clay (less than mm)

26. Soil Composition
Made up of sand, silt, clay, rocks, humus, microorganisms (bacteria, fungi, algae, protists, insects, worms, roots)
Soil contains a mixture of different sized particles
_______ – roughly equal amounts of sand, silt, and clay – most fertile
Loams

27. The availability of soil water and minerals

28. The availability of soil water and minerals
Plant takes up water not tied to hydrophilic soil particles
Positively charged ions attach to soil
H+ help displace minerals attached to soil
Roots add H+ to the soil directly and through the release of ____
(reacts with water to form carbonic acid)
CO2

29. The availability of soil water and minerals

30. Soil Conservation
Fertilizers
(Nitrogen, Phosphorus, Potassium)

31. The Nation that Destroys Its Soil Destroys Itself – Franklin D
The Nation that Destroys Its Soil Destroys Itself – Franklin D. Roosevelt 1937

32. Loss of Topsoil 1930’s “_____________”
Black Blizzards
1930’s “_____________”
Due to inappropriate farming in late 1800’s and early 1900’s
Wheat and cattle farming
Droughts
Steinbeck’s Grapes of Wrath
30% of world’s farmlands have reduced production due to poor soil conditions.

33. Nitrogen Fixation

34. Nitrogen Fixation Plants absorb nitrogen in the form of nitrate
_____________ and ammonifying bacteria produce ammonium
Ammonium is shifted to nitrate by nitrifying bacteria
Plants shift nitrate back to ammonium for use
Nitrogen-fixing

35. Nitrogen Fixation

36. Unusual Nutritional Adaptations in Plants - Epiphytes

37. Unusual Nutritional Adaptations in Plants - Mistletoe

38. Unusual Nutritional Adaptations in Plants – Venus Fly Traps

39. Unusual Nutritional Adaptations in Plants – Pitcher Plants

40. Unusual Nutritional Adaptations in Plants - Sundews

41. Control Systems in Plants

42. Plant Hormones Coordinates growth Coordinates development
Coordinates responses to environmental stimuli

43. Plant Hormones Auxin (IAA) Cytokinins Gibberllins Abscisic Acid
Ethylene
Oligogaccharins
Brassinosteroids

44. Auxins Stimulates stem elongation Stimulates root growth
Stimulates differentiation and branching
Stimulates development of fruit
Stimulates apical dominance
Stimulates phototropism and gravitropism

45. Auxin Control Auxin stimulates growth
Auxin block on right causes cells to elongate and the plant bends left
Auxin block on left causes cells to elongate the the plant bends right

46. ___________ Hypothesis
Acid Growth
Proton pump stimulated by auxin lower pH of wall
H+ activates Enzyme
Enzyme breaks hydrogen bonds in cellulose
Wall takes up water and elongates

47. Auxin Others
Promotes secondary growth by stimulating vascular cambium and secondary xylem
Promotes adventitious root at the base of a cut stem
Promotes fruit growth without pollination (seedless tomatoes)

48. Cytokinins Stimulates root growth
Stimulates cell division and differentiation (with auxins)
more cytokinin - shoot buds develop
more auxin - roots develop
Stimulates germination
Delays Senescence

49. Gibberellins Promotes seed and bud germination
Promotes stem elongation
Promotes leaf growth
Stimulates flowering and fruits
(with auxin)

50. Abscisic Acid Slows growth Closes stomata under water stress
Permits seed dormancy

51. Ethylene Promotes fruit ripening
Controls Abscission (causes leaf loss)

52. Plant Movements
Phototropism
Gravitropism
____________
Thigmotrophism

53. Plant Movement Rapid Leaf Movement (39.27)
drop in turgor pressure within pulvini
sent by action potentials

54. Plant Movement Sleep Movements (39.21)
cells on opposite sides of pulvinus control the movement

55. Daily and Seasonal Responses
Circadian Rhythm
Photoperiodism
controls flowering (short-day vs. long-day)
critical night length

56. Photoperiodic Control

57. Flowering Hormones
Experiment indicates the presence of some type of flowering hormone

58. Phytochromes
Function as photoreceptors / red (660nm) to far red (730nm)
Activates kinases (regulatory proteins)

59. Red vs. Far Red Response

60. Plant Responses to Environmental Stress
Water Deficit
Oxygen Deprivation
Salt Stress
Heat Stress
Cold Stress
Herbivores

61. Responses to Herbivores
Produce _________ (an amino acid similar to arginine)
Recruitment of predatory animals
Canavanine

62. Why plants are important?
Food!
Humans have domesticated plants for 13,000 years.
____ of all the calories consumed by humans come from six crops: Wheat, Rice, Maize, Potatoes, Cassava, and Sweet Potatoes.
Also, we use plants to feed cattle, 5-7kg to produce 1 kg of beef.
80%

63. Pyramid of Net Productivity63

64. Plants remove CO2 64

65. Only 5,000 of 290,000 species have been studied.
_____ of all US Prescription Drugs contain one or more active ingredients from plants.
____ earth’s species will become extinct within the next 100 years (larger than the Permian or Cretaceous)
Only 5,000 of 290,000 species have been studied.
3-4 species per hour,
27,000 per year!
25%
50%

66. Cinchona tree Bark contains __________ Grows in the Andes in peru
Used since the early 1600’s to treat malaria
quinine

67. Aspirin Acetylsalicylic acid or ASA Dates back to 3000 B.C.
Greek Physician Hippocrates prescribed it.
From _____________ and other Salicylate-rich plants (leaves and bark)
Scientists at Bayer began investigating acetylsalicylic acid as a less-irritating replacement for standard common salicylate medicines. By 1899, Bayer named it this Aspirin
Willow trees