Plant Biology Course: Exploring Plant Development and Applications

1. Plan A • Standard lecture course • Plan B • Standard lecture course, except: • Last lectures will be chosen by you -> electives • Last 4 labs will be an independent research project • 20% of grade will be “elective” • Paper • Talk • Research proposal • Poster • Exam

2. Plan C • We will pick a problem in plant biology and see where it takes us. • Phytoremediation • Plant products • Biofuels • Climate/CO2 change • Stress responses/stress avoidance • Improving food production • Biotechnology • Plant movements • Plant signaling (including neurobiology) • Flowering? • Something else?

3. Plan C Pick a problem Pick some plants to study Design some experiments See where they lead us

4. Plan C • Grading? • Combination of papers and presentations • First presentation: 5 points • Research presentation: 10 points • Final presentation: 15 points • Assignments: 5 points each • Poster: 10 points • Intermediate report 10 points • Final report: 30 points • Alternatives • Paper(s) instead of 1 or two presentations • Research proposal instead of a presentation • One or two exams? • Scavenger hunts?

5. Vegetative Plants • 3 Parts • Leaf • Stem • Root

6. Vegetative Plants 3 tissue types • Dermal • Ground • Vascular

7. Plant Development • Cell division = growth

8. Plant Development • Cell division = growth • Determination = what cell can become

9. Plant Development • Cell division = growth • Determination = what cell can become • Differentiation = cells become specific types

10. Plant Development • Cell division = growth • Determination = what cell can become • Differentiation = cells become specific types • Pattern formation: developing specific structures in specific locations

11. Plant Development • Cell division = growth • Determination = what cell can become • Differentiation = cells become specific types • Pattern formation • Morphogenesis: organization into tissues & organs

12. Plant Development • umbrella term for many processes • embryogenesis

13. Plant Development • umbrella term for many processes • Embryogenesis • Seed dormancy and germination

14. Plant Development • umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis

15. Plant Development • umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis • Transition to flowering, fruit • and seed formation

16. Plant Development • umbrella term for many processes • Embryogenesis • Seed dormancy and germination • Seedling Morphogenesis • Transition to flowering, fruit • and seed formation • Many responses to environment

17. Plant Development • Umbrella term for many processes • Unique features of plant development • Cell walls: can’t move:

18. Plant Development • Umbrella term for many processes • Unique features of plant development • Cell walls: can’t move: • Must grow towards/away from signals

19. Plant Development • Umbrella term for many processes • Unique features of plant development • Cell walls: cells can’t move: must grow instead • Plasticity: plants develop in • response to environment

20. Unique features of plant development • Cell walls: cells can’t move • Plasticity: plants develop in response to environment • Totipotency: most plant cells can form an entire new plant given the correct signals

21. Unique features of plant development • Cell walls: cells can’t move • Plasticity: plants develop in response to environment • Totipotency: most plant cells can form an entire new plant given the correct signals • Meristems: plants have perpetually embryonic regions, and can form new ones

22. Unique features of plant development • Cell walls: cells can’t move • Plasticity: plants develop in response to environment • Totipotency: most plant cells can form an entire new plant given the correct signals • Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line!

23. Unique features of plant development • Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line! Cells at apical meristem become • flowers: allows Lamarckian evolution!

24. Unique features of plant development • Meristems: plants have perpetually embryonic regions, and can form new ones • No germ line! Cells at apical meristem become • flowers: allows Lamarckian evolution! • Different parts of the same 2000 year old tree have different DNA & form • different gametes

25. Cell walls • Carbohydrate barrier • surrounding cell • Protects & gives cell shape • 1˚ wall made first • mainly cellulose • Can stretch!

26. Cell walls • Carbohydrate barrier • surrounding cell • Protects & gives cell shape • 1˚ wall made first • mainly cellulose • Can stretch! • 2˚ wall made after growth stops

27. Cell walls • Carbohydrate barrier • surrounding cell • Protects & gives cell shape • 1˚ wall made first • mainly cellulose • Can stretch! • 2˚ wall made after growth stops • Lignins make it tough

28. Cell walls • Carbohydrate barrier surrounding cell • Protects & gives cell shape • 1˚ wall made first • mainly cellulose • Can stretch! • 2˚ wall made after growth stops • Lignins make it tough

29. Cell walls • 1˚ wall made first • 2˚ wall made after growth stops • Lignins make it tough • Problem for "cellulosic Ethanol" from whole plants • Middle lamella = space between 2 cells

30. Cell walls • 1˚ wall made first • 2˚ wall made after growth stops • Middle lamella = space • between 2 cells • Plasmodesmata = gaps in walls • that link cells

31. Cell Walls • Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane

32. Cell Walls • Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane • Desmotubule joins ER of both cells

33. Cell Walls • Plasmodesmata = gaps in walls that link cells • Lined with plasma membrane • Desmotubule joins ER of both cells • Exclude objects > 1000 Dalton, yet viruses move through them!

34. Types of Organelles 1) Endomembrane System 2) Putative endosymbionts

35. Endomembrane system • Common features • derived from ER

36. Endomembrane system • Common features • derived from ER • transport is in vesicles

37. Endomembrane system • Common features • derived from ER • transport is in vesicles • proteins & lipids are • glycosylated

38. Endomembrane system Organelles derived from the ER 1) ER 2) Golgi 3) Vacuoles 4) Plasma Membrane 5) Nuclear Envelope 6) Endosome 7) Oleosomes

39. ER Network of membranes t/out cell 2 types: SER & RER

40. SER • tubules that lack ribosomes • fns: • Lipid syn • Steroid syn • drug detox • storing Ca2+ • Glycogen • catabolism

41. RER • Flattened membranes studded with ribosomes • 1˚ fn = protein synthesis • -> ribosomes are making proteins

42. ER • SER & RER make new membrane!

43. GOLGI COMPLEX Flattened stacks of membranes made from ER

44. GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack

45. GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack Makes most cell wall carbohydrates!

46. GOLGI COMPLEX Individual, flattened stacks of membranes made from ER Fn: “post office”: collect ER products, process & deliver them Altered in each stack Makes most cell wall carbohydrates! Protein’s address is built in

47. VACUOLES • Derived from Golgi; Fns: • 1)digestion • a) Organelles • b) food particles

48. VACUOLES • Derived from Golgi; Fns: • 1)digestion • a) Organelles • b) food particles • 2) storage

49. VACUOLES • Derived from Golgi; Fns: • 1) digestion • a) Organelles • b) food particles • 2) storage • 3) turgor: push plasma • membrane against • cell wall

50. VACUOLES Vacuoles are subdivided: lytic vacuoles are distinct from storage vacuoles!