1. Plant Growth & Development 3 stages 1.Embryogenesis Fertilization to seed

2. Plant Growth & Development 3 stages 1.Embryogenesis Fertilization to seed 2. Vegetative growth Juvenile stage Germination to adult

3. Plant Growth & Development 3 stages 1.Embryogenesis Fertilization to seed 2. Vegetative growth Juvenile stage Germination to adult "phase change" marks transition

4. Plant Growth & Development 3 stages 1.Embryogenesis Fertilization to seed 2. Vegetative growth Juvenile stage Germination to adult "phase change" marks transition 3. Reproductive development Make flowers, can reproduce sexually

5. Sexual reproduction 1.haploid gametogenesis in flowers: reproductive organs Female part = pistil (gynoecium) Stigma Style Ovary Ovules

6. Sexual reproduction 1.haploid gametogenesis in flowers: reproductive organs Female part = pistil (gynoecium) Stigma Style Ovary Ovules Male part : anthers Make pollen

7. (Wilson & Yang, 2004, Reproduction) Sexual reproduction 1. making haploid gametes in flowers Pollen = male, 2-3 cells Made in anther locules Archesporial cell Primary sporogenous cells Microspores Pollen mother cells Primary parietal cells 2 o parietal cells Endothecium Tapetum Middle cell layer meiosis

8. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Made in anthers Microspores divide to form vegetative cell and germ cell

9. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Made in anthers Microspores divide to form vegetative cell and germ cell Germ cell divides to form 2 sperm cells, but often not until it germinates

10. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Made in anthers Microspores divide to form vegetative cell and germ cell Germ cell divides to form 2 sperm cells, but often not until it germinates Pollen grains dehydrate and are coated

11. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Made in anthers Microspores divide to form vegetative cell and germ cell Germ cell divides to form 2 sperm cells, but often not until it germinates Pollen grains dehydrate and are coated Are released, reach stigma, then germinate

12. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Egg = female, made in ovaries

13. Sexual reproduction 1. making haploid gametes in flowers Pollen = male, contains 2-3 cells Egg = female, made in ovaries Megaspore mother cell → meiosis → 4 haploid megaspores

14. Sexual reproduction Megaspore mother cell → meiosis → 4 haploid megaspores 3 die Functional megaspore divides 3 x w/o cytokinesis http://www.biologie.uni-hamburg.de/b- online/library/webb/BOT201/Angiosperm/MagnoliophytaLab99/OvuleForm700.jpg

15. Sexual reproduction Megaspore mother cell → meiosis → 4 haploid megaspores 3 die Functional megaspore divides 3 x w/o cytokinesis Cellularization forms egg, binucleate central cell, 2 synergids & 3 antipodals http://www.biologie.uni-hamburg.de/b- online/library/webb/BOT201/Angiosperm/MagnoliophytaLab99/OvuleForm700.jpg

16. Sexual reproduction Cellularization forms egg, binucleate central cell, 2 synergids & 3 antipodals Egg, synergids & central cell are essential http://www.biologie.uni-hamburg.de/b- online/library/webb/BOT201/Angiosperm/MagnoliophytaLab99/OvuleForm700.jpg

17. Sexual reproduction Cellularization forms egg, binucleate central cell, 2 synergids & 3 antipodals Egg, synergids & central cell are essential In many spp antipodals degenerate http://www.biologie.uni-hamburg.de/b- online/library/webb/BOT201/Angiosperm/MagnoliophytaLab99/OvuleForm700.jpg

18. Sexual reproduction 1.making haploid gametes in flowers 2.Pollen lands on stigma & germinates if good signals

19. Sexual reproduction 1.making haploid gametes in flowers 2.Pollen lands on stigma & germinates if good signals Forms pollen tube that grows through style to ovule

20. Sexual reproduction Pollen lands on stigma & germinates if good signals Forms pollen tube that grows through style to ovule Germ cell divides to form sperm nuclei

21. Sexual reproduction Pollen lands on stigma & germinates if good signals Forms pollen tube that grows through style to ovule Germ cell divides to form sperm nuclei Pollen tube reaches micropyle & releases sperm nuclei into ovule

22. Sexual reproduction Pollen tube reaches micropyle & releases sperm nuclei into ovule Double fertilization occurs!

23. Sexual reproduction Pollen tube reaches micropyle & releases sperm nuclei into ovule Double fertilization occurs! One sperm fuses with egg to form zygote

24. Sexual reproduction Pollen tube reaches micropyle & releases sperm nuclei into ovule Double fertilization occurs! One sperm fuses with egg to form zygote Other fuses with central cell to form 3n endosperm

25. Sexual reproduction Pollen tube reaches micropyle & releases sperm nuclei into ovule Double fertilization occurs! One sperm fuses with egg to form zygote Other fuses with central cell to form 3n endosperm Synergids play key role in releasing & guiding sperm cells

26. Embryogenesis One sperm fuses with egg to form zygote Other fuses with central cell to form 3n endosperm Development starts immediately!

27. Embryogenesis Development starts immediately! Controlled by genes, auxin & cytokinins Apical cell after first division becomes embryo, basal cell becomes suspensor

28. Embryogenesis Development starts immediately! Controlled by genes, auxin & cytokinins Apical cell after first division becomes embryo, basal cell becomes suspensor Key events 1.Establishing polarity: starts @ 1 st division

29. Embryogenesis 1.Establishing polarity: starts @ 1 st division 2.Establishing radial patterning: periclinal divisions form layers that become dermal, ground & vascular tissue

30. Embryogenesis 1.Establishing polarity: starts @ 1 st division 2.Establishing radial patterning: periclinal divisions form layers that become dermal, ground & vascular tissue 3.Forming the root and shoot meristems

31. Embryogenesis 1.Establishing polarity: starts @ 1 st division 2.Establishing radial patterning: periclinal divisions form layers that become dermal, ground & vascular tissue 3.Forming the root and shoot meristems 4.Forming cotyledons & roots

32. Embryogenesis 1.Establishing polarity: starts @ 1 st division 2.Establishing radial patterning: periclinal divisions form layers that become dermal, ground & vascular tissue 3.Forming the root and shoot meristems 4.Forming cotyledons & roots Body plan is formed during embryogenesis: seedling that germinates is a juvenile plant with root and apical meristems

33. Embryogenesis End result is seed with embryo packaged inside protective coat

34. Embryogenesis End result is seed with embryo packaged inside protective coat Endosperm feeds developing embryo (3n grows faster)

35. Embryogenesis End result is seed with embryo packaged inside protective coat Endosperm feeds developing embryo (3n grows faster) In many dicots endosperm is absorbed as seed develops

36. Embryogenesis End result is seed with embryo packaged inside protective coat Endosperm feeds developing embryo (3n grows faster) In many dicots endosperm is absorbed as seed develops In many monocots endosperm is seedling food

37. Embryogenesis Body plan is formed during embryogenesis: seedling that germinates is a juvenile plant with root and apical meristems, roots & shoots

38. Embryogenesis Body plan is formed during embryogenesis: seedling that germinates is a juvenile plant with root and apical meristems, roots & shoots Later stages of seed development load nutrients and form protective coat

39. Embryogenesis Later stages of seed development load nutrients and form protective coat Final stages involve desiccation (to 5% moisture content) & dormancy

40. Embryogenesis Later stages of seed development involve loading nutrients and forming protective coat Final stages involve desiccation (to 5% moisture content) & dormancy -> Abscisic acid plays important role

41. Embryogenesis Later stages of seed development load nutrients and form protective coat Final stages involve desiccation (to 5% moisture content) & dormancy -> Abscisic acid plays important role Coordinated with fruit ripening: fruit’s job is to protect & disperse seed

42. Seed germination Coordinated with fruit ripening: fruit’s job is to protect & disperse seed Seeds remain dormant until sense appropriate conditions: some date palms germinated after 2000 years!

43. Seed germination Seeds remain dormant until sense appropriate conditions: some date palms germinated after 2000 years! Water

44. Seed germination Seeds remain dormant until sense appropriate conditions: some Lotus germinated after 2000 years! Water Temperature: some seeds require vernalization = prolonged cold spell

45. Seed germination Seeds remain dormant until sense appropriate conditions: some Lotus germinated after 2000 years! Water Temperature: some seeds require vernalization = prolonged cold spell May degrade hydrophobic seed coat

46. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell May degrade hydrophobic seed coat May disperse inhibitor (eg Abscisic acid)

47. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell May degrade hydrophobic seed coat May disperse inhibitor (eg Abscisic acid) Many require light

48. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell May degrade hydrophobic seed coat May disperse inhibitor (eg Abscisic acid) Many require light: says that they will soon be able to photosynthesize

49. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell May degrade hydrophobic seed coat May disperse inhibitor (eg Abscisic acid) Many require light: says that they will soon be able to photosynthesize: often small seeds with few reserves

50. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell Many require light: says that they will soon be able to photosynthesize: often small seeds with few reserves Some need acid treatment or scarification

51. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature: some seeds require vernalization = prolonged cold spell Many require light: says that they will soon be able to photosynthesize: often small seeds with few reserves Some need acid treatment or scarification Passage through bird gut

52. Seed germination Seeds remain dormant until sense appropriate conditions: Water Temperature Many require light Some need acid treatment or scarification Passage through bird gut Some need fire

53. Seed germination Seeds remain dormant until sense appropriate conditions: Some need acid treatment or scarification Passage through bird gut Some need fire Hormones can also trigger (or stop) germination

54. Seed germination Seeds remain dormant until sense appropriate conditions: Hormones can also trigger (or stop) germination Germination is a two step process Imbibition is purely physical: seed swells as it absorbs water until testa pops. Even dead seeds do it.

55. Seed germination Germination is a two step process Imbibition is purely physical: seed swells as it absorbs water until testa pops. Even dead seeds do it. Next embryo must start metabolism and cell elongation

56. Seed germination Germination is a two step process Imbibition is purely physical: seed swells as it absorbs water until testa pops. Even dead seeds do it. Next embryo must start metabolism and cell elongation This part is sensitive to the environment, esp T & pO 2

57. Seed germination Germination is a two step process Imbibition is purely physical: seed swells as it absorbs water until testa pops. Even dead seeds do it. Next embryo must start metabolism and cell elongation This part is sensitive to the environment, esp T & pO 2 Once radicle has emerged, vegetative growth begins

58. Vegetative growth Once radicle has emerged, vegetative growth begins Juvenile plants in light undergo photomorphogenesis Initially live off reserves, but start making photosynthetic leaves

59. Vegetative growth Once radicle has emerged, vegetative growth begins Juvenile plants in light undergo photomorphogenesis Initially live off reserves, but start making photosynthetic leaves Roots grow down seeking water & nutrients

60. reproductive phase Eventually switch to reproductive phase & start flowering Are now adults!

61. reproductive phase Eventually switch to reproductive phase & start flowering Are now adults! Time needed varies from days to years

62. reproductive phase Eventually switch to reproductive phase & start flowering Are now adults! Time needed varies from days to years. Shoot apical meristem now starts making new organ: flowers, with many new structures & cell types