Card Set Information
class; auxin, giberellins, cutokinins
specific, abscisic acid
molecules, ethylene gas
acidic acid chain, one aromatic ring,
throughout plant, highest conc in meri and growing tissue, synthesised in embryo and meristems
cell elongation, root initiation, roles in other random developmental shit.
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
all have same 3 carbon ring skeleton
role in flower and fruit development
synth in and found in; developing seed and fruit, young leaves and shoot apex, root apex
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
GA cues plant to release from dormancy,,,bud or seed
synthesis of a-amylase in aleurone layer of seed,break down starch in endosperm,,which gets used for energy by seedling
: spray flowers with GA at right time
interferes with seed development
GA interarts with auxin to?
control sex expression in monoecious plants
perfect single flower with male and female organs
one sex per flower, multiple flowers per plant...can be gyno and andro if exposed to certain hormones such as auxin or GA
all female flowers
all male flowers
one sex perplant no exceptions
derivative of adenin, lots of nitrogen
synth in root, transport in xlem, high conc in immature seeds and developing fruit, delays senescence (aging)
stimulate cell division, active in most aspect of grwth and dvlpmnt
abscisic acid (ABA)?
specific molecule no variant,
mature leaves, synth in cytoplasm of mesophyll cells(cntr of leaf)
storage protein synth during seed dvlpmnt,prevents germination,,,dormancy is a balance of ABA + GA, modulates water stress-close stomata to prevent water loss..
causes influx of Ca into cells, high conc in human brain.. involved in intracellular pathways it a conserved mech of evol
found throughout plant,especially in epidermis,seed coat,and senesing and ripening tissue,,,,synth in response to stress>including excess auxin
inhibits auxin synthesis,,inhibits elongation,promotes radial growth(thinkness),primary role is to promote flowering and fruit ripening
autocatalytic(positive feedback), control sex expression in monoecious plants>spraying w ethylene makes F flowers
4 c ring steroid hormon, found throughout
stimulate shoot elongation, ethylene production>which inhibits root grwth and dvlpmnt
protein stability, membrane permeability
seed germination, defense proteins (insect and disease resistant)
mitosis, growth, differentiation
cell division is stimulated by
auxins and cytokinins
cell proliferation occurs w auxins and CK
auxin and CK promote?
accumulation of cyclin D reuired to activate CDK , promotes transiton from G-synth
DEVELOPMENT (auxin and CK)
absence of either auxin or CK arrests cell in G1 or G2, remove either to create barrier
increase cell size, signal on tip sends down to dark side cells to grow,,,bend to light.
acid growth hyp
auxin increase the sensibility of cell wall, it decreases ph so atp actively transports H out of cell... (active expansion
indirect action between auxin and atpase..auxin receptors intiate a signal transduction mech
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)
transport of auxin
shoots mostly, basipetally (apex to base,,,minimal acropetal) transports both ways.. not gravity induced...
ph gradient drives iaa uptake, polar iaa efflux ... gradient
auxin plays a role in
apical dominance...high conc from apical bud dormants lateral buds...CK release buds from dormancy..
vascular differntiation regulated by
auxin and CK...
fert,embry dvlpmnt/endosperm formation, auxin and GA>cell enlargement/build nutrient reserve, maturation (aba) prep for dormancy.
seed germination while still in fruit
(water uptake), embryo elongation (iaa) ga induced A-amylase (mobilize nut reserves), seed grows
taking up water.... seed dehydrate be4 formancy, take up water to grow.. some need to break coat inorder to absorb...
(need iaa) supplied from stores untill embry can produce its own
mobilization and nutrients.
GA induced A-amylase, embry intiates seq of events
internodal elngation in stems, and it causes bolting...growth of stems as opposed to rosette just leaves...
threshold dependent...in stem growth its triggered by photoperiod and low temp
auxin very low >root growth....mid inhibits root growth...higher> promotes initaiation of secondary roots...
elongation vs dvsion and elongation
auxin only elong...auxin and CK divide and elongate
senescences of leaves and fruits
when scenescence/stress auxin leaves leaf this causes abcission layer...
auxin and ethylene female...GA male..
auxin or GA depends on species