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Game plan

Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower. Game plan We will study effects of elevated CO 2 and temperature on flowering time and see where it takes us.

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Game plan

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  1. Game plan We will study effects of elevated CO2 and temperature on flowering time and see where it takes us. 1. Learn more about how plants choose when to flower

  2. Game plan • We will study effects of elevated CO2 and temperature on flowering time and see where it takes us. • 1. Learn more about how plants choose when to flower • Environmental influences on flowering

  3. Game plan • We will study effects of elevated CO2 and temperature on flowering time and see where it takes us. • 1. Learn more about how plants choose when to flower • Environmental influences on flowering • 2. Pick some plants to study

  4. Game plan • We will study effects of elevated CO2 and temperature on flowering time and see where it takes us. • 1. Learn more about how plants choose when to flower • Environmental influences on flowering • 2. Pick some plants to study • 3. Get them growing

  5. Game plan • We will study effects of elevated CO2 and temperature on flowering time and see where it takes us. • 1. Learn more about how plants choose when to flower • Environmental influences on flowering • 2. Pick some plants to study • 3. Get them growing • 4. Design some experiments for other things to test before they start flowering

  6. Game plan Suggestions Arabidopsis 2. Fast plant 3. Sorghum 4. Brachypodium distachyon 5. Amaranthus 6. Quinoa 7. Kalanchoe 8. Venus fly traps Options Pick several plants

  7. Game plan • Suggestions • Arabidopsis 2. Fast plant • 3. Sorghum 4. Brachypodium distachyon • 5. Amaranthus 6. Quinoa • 7. Kalanchoe 8. Venus fly traps • Options • Pick several plants • C3, C4, CAM

  8. Game plan • Suggestions • Arabidopsis 2. Fast plant • 3. Sorghum 4. Brachypodium distachyon • 5. Amaranthus 6. Quinoa • 7. Kalanchoe 8. Venus fly traps • Options • Pick several plants • C3, C4, CAM • Long Day, short day, Day neutral

  9. Game plan • Suggestions • Arabidopsis 2. Fast plant • 3. Sorghum 4. Brachypodium distachyon • 5. Amaranthus 6. Quinoa • 7. Kalanchoe 8. Venus fly traps • Options • Pick several plants • C3, C4, CAM • Long Day, short day, Day neutral • Tropical, temperate, arctic

  10. Game plan • Suggestions • Arabidopsis 2. Fast plant • 3. Sorghum 4. Brachypodiumdistachyon • 5. Amaranthus6. Quinoa • 7. Kalanchoe8. Venus fly traps • Options • Pick several plants • C3, C4, CAM • Long Day, short day, Day neutral • Tropical, temperate, arctic • ?????

  11. Game plan • Suggestions • Arabidopsis 2. Fast plant • 3. Sorghum 4. Brachypodiumdistachyon • 5. Amaranthus6. Quinoa • 7. Kalanchoe8. Venus fly traps • Options • Pick several plants • C3, C4, CAM • Long Day, short day, Day neutral • Tropical, temperate, arctic • ????? • Pick one plant • Study many conditions

  12. Options • Pick several plants • C3, C4, CAM • Long Day, short day, Day neutral • Tropical, temperate, arctic • ????? • Pick one plant • Study many conditions • Study many variants/mutants • ?????

  13. Grading? • Combination of papers, presentations & lab reports • 4 lab reports @ 2.5 points each • 5 assignments @ 2 points each • Presentation on global change and plants: 5 points • Research proposal: 10 points • Final presentation: 15 points • Poster: 10 points • Draft report 10 points • Final report: 30 points • Assignment 1 • Pick a plant that might be worth studying • Try to convince the group in 5-10 minutes why yours is best: i.e., what is known/what isn’t known

  14. Plant Growth & Development Occurs in 3 stages • Embryogenesis From fertilization to seed 2. Vegetative growth Juvenile stage From seed germination to adult "phase change" marks transition 3. Reproductive development Start making flowers, can reproduce sexually

  15. Transition to Adult Phase • Juveniles & adults are very different!

  16. Transition to Flowering • Adults are competent to flower, but need correct signals • Very complex process! • Can be affected by: • Daylength • Temperature (especially cold!) • Water stress • Nutrition • Hormones

  17. Early Studies • Julius Sachs (1865) first proposed florigen • Garner and Allard (1920) discovered photoperiodism • Maryland Mammoth tobacco flowers in the S but not in N • Knott (1934) day length is perceived by the leaves

  18. Early Studies • Knott (1934) day length is perceived by the leaves • Flowers are formed at SAM! • Florigen moves from leaves • to SAM • Is graft-transmissable! • Moves in phloem

  19. Complications • Some plants are qualitative (must have correct daylength), others are quantitative (correct days speed flowering) • Four pathways control flowering: • Photoperiod • PHY only • PHY + CRY • Vernalization: requires cold period • gibberellin(GA) • Autonomous

  20. Complications • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time

  21. Genes controlling flowering • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time • CONSTANS (CO): co mutants are day-length insensitive & flower late

  22. Genes controlling flowering • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time • CONSTANS (CO): co mutants are day-length insensitive & flower late • CO mRNA is expressed in leaf but not SAM & increases in LD

  23. Genes controlling flowering • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time • CONSTANS (CO): co mutants are day-length insensitive & flower late • CO mRNA is expressed in leaf but not SAM & increases in LD • CO encodes a ZN-finger transcription factor (TF) that induces expression of FLOWERING LOCUS T (FT)

  24. Genes controlling flowering • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time • CONSTANS (CO): co mutants are day-length insensitive & flower late • CO mRNA is expressed in leaf but not SAM & increases in LD • CO encodes a ZN-finger TF that induces expression of FLOWERING LOCUS T (FT) • FLOWERING LOCUS T (FT): a strong promoter of flowering

  25. Genes controlling flowering • Florigen is “universal”: transmitted from LDP to SDP and vice-versa via grafts • Solved by identifying genes that control flowering time • CONSTANS (CO): co mutants are day-length insensitive & flower late • CO mRNA is expressed in leaf but not SAM & increases in LD • CO encodes a ZN-finger TF that induces expression of FLOWERING LOCUS T (FT) • FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein

  26. Genes controlling flowering • CONSTANS (CO): co mutants are day-length insensitive & flower late • FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein • FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses flowering

  27. Genes controlling flowering • CONSTANS (CO): co mutants are day-length insensitive & flower late • FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein • FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses flowering • Highly expressed in non-vernalized tissues

  28. Genes controlling flowering • CONSTANS (CO): co mutants are day-length insensitive & flower late • FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein • FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses flowering • Highly expressed in non-vernalized tissues • Turned off by vernalization due to chromatin mod

  29. Genes controlling flowering • CONSTANS (CO): co mutants are day-length insensitive & flower late • FLOWERING LOCUS T (FT): a strong promoter of flowering: encodes a RAF kinase inhibitor protein • FLOWERING LOCUS C (FLC): a MADS-box gene strongly represses flowering • Highly expressed in non-vernalized tissues • Turned off by vernalization due to chromatin mod • SUPPRESSOR OF CONSTANS 1 (SOC1): a MADS-BOX TF that activates genes for floral development.

  30. Transition to flowering Upon induction, CO activates transcription of FT in leaves FT protein moves from leaves to shoot apex in phloem!

  31. Transition to flowering Upon induction, CO activates transcription of FT in leaves FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 & AP1

  32. Transition to flowering Upon induction, CO activates transcription of FT FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 &AP1 These activate LFY & Flower genes

  33. Transition to flowering Upon induction, CO activates transcription of FT FT protein moves from leaves to shoot apex in phloem! In SAM combines with FD to activate SOC1 &AP1 These activate LFY & Flower genes Other signals converge On SOC1, either Directly or via FLC

  34. SDP • Rice homolog to CO is Hd1 • Inhibits expression of Hd3a • (the FT homolog)

  35. SDP • Rice homolog to CO is Hd1 • Inhibits expression of Hd3a • (the FT homolog) • Induced by long days

  36. SDP • Rice homolog to CO is Hd1 • Inhibits expression of Hd3a • (the FT homolog) • Induced by long days • Only make Hd3a protein • under short days

  37. Transition to flowering • Eventually 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

  38. WATER • Plants' most important chemical • most often limits productivity

  39. WATER • Plants' most important chemical • most often limits productivity • Often >90%% of a plant cell’s weight

  40. WATER • Plants' most important chemical • most often limits productivity • Often >90%% of a plant cell’s weight • Gives cells shape

  41. WATER • Plants' most important chemical • most often limits productivity • Often >90%% of a plant cell’s weight • Gives cells shape • Dissolves many chem

  42. WATER • Dissolves many chem • most biochem occurs in water • Source of e- for PS

  43. WATER • most biochem occurs in water • Source of e- for PS • Constantly lose water due to PS (1000 H2O/CO2)

  44. WATER • most biochem occurs in water • Source of e- for PS • Constantly lose water due to PS • Water transport is crucial!

  45. WATER • Water transport is crucial! • SPAC= Soil Plant Air Continuum • moves from soil->plant->air

  46. WATER Formula = H2O Formula weight = 18 daltons Structure = tetrahedron, bond angle 104.5˚

  47. WATER • Structure = tetrahedron, bond angle 104.5˚ • polar :O is more attractive to electrons than H • + on H • - on O

  48. Water • Polarity is reason for water’s properties • water forms H-bonds with polar molecules

  49. Water • Polarity is reason for water’s properties • water forms H-bonds with polar molecules • Hydrophilic = polar molecules • Hydrophobic = non-polar molecules

  50. Properties of water • Cohesion = water H-bonded to water -> reason for surface tension

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