1. phystohormones
    • class; auxin, giberellins, cutokinins
    • specific, abscisic acid
    • molecules, ethylene gas
  2. auxin?
    acidic acid chain, one aromatic ring,
  3. auxin location?
    throughout plant, highest conc in meri and growing tissue, synthesised in embryo and meristems
  4. auxin funstion?
    cell elongation, root initiation, roles in other random developmental shit.
  5. acropetal?
    base-> apex
  6. sythetic auxin include?
    • 2,4 - d (herbicide) stimulates growth elongation and its high energy requirement eventually kills plant
    • and Napthalene(NAA) induces root growth and prevents fruit from abscission
  7. Gibberellins?
    • all have same 3 carbon ring skeleton
    • role in flower and fruit development
  8. Gibberellins location?
    synth in and found in; developing seed and fruit, young leaves and shoot apex, root apex
  9. Gibberellins function?
    stem elongation(via cell wall expansion), break dormancy of buds and seeds, young plants elongation of cells same number of leaves and roots, if stem fully developed then nothing rly
  10. plant dormancy?
    GA cues plant to release from dormancy,,,bud or seed
  11. GA stimulates?
    synthesis of a-amylase in aleurone layer of seed,break down starch in endosperm,,which gets used for energy by seedling
  12. Parthenocarpy?
    • seedless fruit: spray flowers with GA at right time
    • interferes with seed development
  13. GA interarts with auxin to?
    control sex expression in monoecious plants
  14. synoecious?
    perfect single flower with male and female organs
  15. monoecious ?
    one sex per flower, multiple flowers per plant...can be gyno and andro if exposed to certain hormones such as auxin or GA
  16. gynoecious?
    all female flowers
  17. androecious?
    all male flowers
  18. dioecious?
    one sex perplant no exceptions
  19. cytokinins?
    derivative of adenin, lots of nitrogen
  20. CK location?
    synth in root, transport in xlem, high conc in immature seeds and developing fruit, delays senescence (aging)
  21. CK function?
    stimulate cell division, active in most aspect of grwth and dvlpmnt
  22. abscisic acid (ABA)?
    specific molecule no variant,
  23. ABA location?
    mature leaves, synth in cytoplasm of mesophyll cells(cntr of leaf)
  24. ABA function?
    storage protein synth during seed dvlpmnt,prevents germination,,,dormancy is a balance of ABA + GA, modulates water stress-close stomata to prevent water loss..
  25. ABA factoid>
    causes influx of Ca into cells, high conc in human brain.. involved in intracellular pathways it a conserved mech of evol
  26. ethylene?
    found throughout plant,especially in epidermis,seed coat,and senesing and ripening tissue,,,,synth in response to stress>including excess auxin
  27. ethylene function?
    inhibits auxin synthesis,,inhibits elongation,promotes radial growth(thinkness),primary role is to promote flowering and fruit ripening
  28. ethylene facts..
    autocatalytic(positive feedback), control sex expression in monoecious plants>spraying w ethylene makes F flowers
  29. brassinosteroids?
    4 c ring steroid hormon, found throughout
  30. Bsteroids function?
    stimulate shoot elongation, ethylene production>which inhibits root grwth and dvlpmnt
  31. polyamines
    protein stability, membrane permeability
  32. jasmonates
    seed germination, defense proteins (insect and disease resistant)
  33. meristems undergo
    mitosis, growth, differentiation
  34. cell division is stimulated by
    auxins and cytokinins
  35. celldivision
    cell proliferation occurs w auxins and CK
  36. auxin and CK promote?
    accumulation of cyclin D reuired to activate CDK , promotes transiton from G-synth
  37. DEVELOPMENT (auxin and CK)
    absence of either auxin or CK arrests cell in G1 or G2, remove either to create barrier
  38. Auxin stimulates?
    increase cell size, signal on tip sends down to dark side cells to grow,,,bend to light.
  39. acid growth hyp
    auxin increase the sensibility of cell wall, it decreases ph so atp actively transports H out of cell... (active expansion
  40. agh cont
    indirect action between auxin and atpase..auxin receptors intiate a signal transduction mech
  41. agh on applies to
    • initial rapid growth (first hour)
    • need to add synthesis of of new wall units to avoid stretching to thin, small auxin upregulated RNAs(saurs gene),aux/iaa genes
    • (10-60 minutes after auxin added)
  42. transport of auxin
    shoots mostly, basipetally (apex to base,,,minimal acropetal) transports both ways.. not gravity induced...
  43. chemiosmotic hyp.
    ph gradient drives iaa uptake, polar iaa efflux ... gradient
  44. auxin plays a role in
    apical dominance...high conc from apical bud dormants lateral buds...CK release buds from dormancy..
  45. vascular differntiation regulated by
    auxin and CK...
  46. seed development
    fert,embry dvlpmnt/endosperm formation, auxin and GA>cell enlargement/build nutrient reserve, maturation (aba) prep for dormancy.
  47. aba prevents
    seed germination while still in fruit
  48. seed germination
    • imbibition
    • (water uptake), embryo elongation (iaa) ga induced A-amylase (mobilize nut reserves), seed grows
  49. imbibition
    taking up water.... seed dehydrate be4 formancy, take up water to grow.. some need to break coat inorder to absorb...
  50. embry elongation
    (need iaa) supplied from stores untill embry can produce its own
  51. mobilization and nutrients.
    GA induced A-amylase, embry intiates seq of events
  52. GA causes
    internodal elngation in stems, and it causes bolting...growth of stems as opposed to rosette just leaves...
  53. GA is
    threshold stem growth its triggered by photoperiod and low temp
  54. ethylene stunts
    plant growth
  55. root development
    auxin very low >root growth....mid inhibits root growth...higher> promotes initaiation of secondary roots...
  56. shoot:root
    • CK>auxin=shoot
    • CKCK=auxin=callus
  57. elongation vs dvsion and elongation
    auxin only elong...auxin and CK divide and elongate
  58. ethylene promotes
    senescences of leaves and fruits
  59. CK also
    delay senescence
  60. abcission layer
    when scenescence/stress auxin leaves leaf this causes abcission layer...
  61. flowers
    auxin and ethylene female...GA male..
  62. parthenocarpy
    auxin or GA depends on species
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