Term
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Definition
amino acids (proteins), nucleic acids (DAN/RNA), chlorophyll.
NO3-, NH3 and NH4+ |
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Term
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Definition
ATP, nucleic acids (DNA/RNA)& other sugar phosphates, phospholipids, etc.
H2PO4 |
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Term
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Definition
amino acids (methionine & cysteine), coenzyme A, Fe-S clusters in photosynthesis
SO4- |
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Term
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Definition
main cation in cells (osmotic levels in cytoplasm - turgor), enzyme activation
K+ |
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Term
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Definition
secondary messenger, enzye regulation, cell wall (middle lamella, affects membranes
Ca2+ |
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Term
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Definition
chlorophyll, enzyme activation, nucleic acid metabolism, RNA/ribosome structure
Mg2+ |
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Term
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Definition
chlorophyll synthesis, cytochromes, Fe-S clusters
Fe2+ & Fe3+ |
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Term
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Definition
plastocyanin (functions in electron transfer in photosynthesis)
Cu2+ |
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Term
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Definition
chlorophyll synthesis, necessary for some enzymes (oxidases)
Mn2+ |
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Term
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Definition
activates enzymes, transcription
Zn 2+ |
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Term
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Definition
nitrate reductase (reducing and metabolizing nitrogen)
MoO4-2 |
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Term
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Definition
unknown (photosynthesis - the release of oxygen?)
Cl- |
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Term
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Definition
unknown (carbohydrate transport?)
BO3-2 |
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Term
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Definition
needed in mangroves and salt marsh plants that have evolved.
Na+ |
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Term
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Definition
in some grasses i.e. triticum repens, zoysia grass and stinging nettle
H4SiO4 |
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Term
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Definition
some species in Se-rich soils accumulate Se and beome very toxic i.e. locoweed oxytropis and astragalus
Se |
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Term
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Definition
inorganic particles
water
organic materials
air
organisms |
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Term
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Definition
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Term
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Definition
mostly cellulose
Cellulose is negatively charged – consequences:
1) binds cations - returns minerals for re-use by plants
2) provides more surface area for H2O retention
3) reduces packing – better H2O movement/aeration |
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Term
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Definition
5%> organic matter (humus)
is classified by sand/silt/clay % |
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Term
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Definition
| 50% organic matter. often acidic and may become anaerobic (w/o air) |
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Term
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Definition
organic soil
-not too decomposed. you can see the plant parts. |
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Term
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Definition
organic soil
-greater decomposition than peat. |
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Term
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Definition
| roots respire and give off CO2 which reacts with water to acidify the soil. the H+ protons are more nucleophilic and bump off the less nucleophilic cations to bind with the soil. these cations can then be absorbed. |
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Term
| acidification of the soil |
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Definition
-decaying organic matter
-CO2 release by roots (from respiration - only means they have for generating atp)
-release if H+ ions due to H+-ATPase |
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Term
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Definition
pH 3.5-5
-release higher proportion of cations from soild AND from plant
-Fe, Zn, Mn, Cu and the crew are more soluble in acid soil.
-may also cause release of toxic elements such as Al and Mn |
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Term
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Definition
pH 5-7
-best for most plants |
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Term
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Definition
pH 7-9
-salty
-water moves up when it's dry |
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Term
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Definition
-leaching from rain causes soil layers
-leaching also robs minerals
-rain affects pH balance
-more plants, less leaching |
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Term
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Definition
some minerals are more soluble at high pH
ex. molybdenum (Mb)
some are more soluble at low pH
ex. Fe Zn Mn and Cu.
-at high pH (basic) they are oxidized into meal oxides which are insoluble. |
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Term
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Definition
| metals bind to organic molecules (chelators or ligands) and become soluble again. |
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Term
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Definition
| naturally occuring low molecular weight organic compounds from fungi and bacteria that bind Fe to make it soluble |
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Term
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Definition
| the simple fact that things will move from high concentrations to low concentrations via diffusion. ex. minerals into plant. |
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Term
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Definition
| a gradients produced by the plasma membrane to attract cations and regulate cytoplam pH with proton pumps. about -100 to -200 mV. the energy source for the pumps is ATP. |
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Term
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Definition
| a form of transport where one ion or molecule is pumped in or out using ATP by its self. |
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Term
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Definition
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Term
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Definition
| two ions or molecules transported in opposite directions. ex. Na+ out K+ in. |
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Term
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Definition
| two ions/molecules transported in same direction with the concentration gradient. ex. H+ and sucrose. |
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Term
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Definition
| the membrane electromagnetic potential is use to move cations in and anions out. |
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Term
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Definition
| very specific type of transporter for a specific ion or molecule where the transporter binds to the molecule, forms a pore like structure that is open on one end and squeezes it in. they are enzyme driven and can pump more into the cell than simple diffusion. |
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Term
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Definition
| transpoters that are open on both ends. much faster than translocators. they respond to electrochemical potential across membrane. open sometimes (regulated by calcium and hormones). ex. K+ channel |
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Term
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Definition
| transporters. larger openings than ion channels and fille with water. these are less specific than onther transporters. they have an outer membrane of mitochondria and plastids. |
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Term
| symplastic vs. apoplastic transport |
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Definition
| symplastic in cells via plasmodesmata so more controlled and slower. apoplastic between cells via capillary movement so not as much control and faster. |
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Term
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Definition
usually unchanged chemically
-directly incorporated into enzymes or into energy carriers
-they can be cofactors in the active sites of enzymes
ex. Mg2+ is in the middle of chlorophyll |
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Term
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Definition
| usually unchanged chemically before assimilated -typically in leaves. |
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Term
| assimilation of phosphorus |
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Definition
in soil, phosphorous is H2PO4- (phosphate)
aka Pi
in photosynthesis and ATP production:
ADP + H2PO4- -> ATP |
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Term
|
Definition
sulfur occurs in soil as SO4(2-) sulfate
-first incorporated into amino acid cystene (see slide 38 plz) |
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Term
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Definition
STEP ONE
nitrate in soil NO3-
NO3- + 2e- + 2H+ -nitrogen reductase-> NO2- + H2O
(nitrite)
electrons come from NADA or FADH2
nitrate reducatse is
upregulated by nitrate, sugars and light
downregulated by ammonia and amino acids
STEP TWO
nitrite NO2- + 6e- + 8H+ -nitrite reductase-> NH4+ + 2H2O
-elecrons from ferredoxin in leaves
-no ATP consumed in process
-25% of plant's reducing power used for nitrogen.
basically NO3- -> NO2- -> NH4+
nitrate -> nitrite -> ammonium |
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Term
| assimilation of nitrogen (ammonium) |
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Definition
NH4+ is highly reactive so must not be allowed to accumulate in plant
NH4+ + ATP + glutamate -glutamine synthetase-> glutamine and ADP
see slide 41 |
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Term
| assimilation of atmospheric nitrogen |
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Definition
nitrogen fixation
N2 + 12 ATP + 6e- --O2--> 2NH4+ + 12ADP
soil bacterium Rhizobium lives in root nodules of legumes and produces leghemoglobin that binds O2 |
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Term
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Definition
| soil bacterium that lives in root nodules and produces leghemoglobin which binds to O2 and aids in nitrogen fixation |
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Term
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Definition
nitrogen is expensive to make.
-it's channeled into seeds
-it's channeled from leaves before they abscise
-proteinases degrade proteins into amino acids
-nucleases degrade DNA/RNA into nucleotides
-decrease the amino acid levels in aging plant parts |
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Term
|
Definition
plant body doesn't form crystals/polymers
-much is stored in the central vacuole but not in large amounts
seeds have lots of storage of proteins in crystal form.
-phytin crystals
-amino acids
-phosphate
and metals |
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Term
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Definition
| 6 carbon sugar w/ phosphate on each of 6 OH- & replaces protons with metal ions K+, Mg2+ Ca2+ and Zn2+ |
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Term
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Definition
irreversible increase in mass
-cell enlargement and expansion |
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Term
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Definition
change from generalized cell type to specialized one with specific functions
-about 50 different cell types in plants |
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Term
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Definition
development of form/shape in cell, organ or entire plant
ex. leaf primordia -> leaf |
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Term
| characteristics of plant growth |
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Definition
-localized, arithmetic growth
-open growth: continue to initiate new organs thoughout lifespan
-indeterminate: continue to grow
-cell differentiation is reversible*
totipotency |
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Term
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Definition
| single differentited cell can de-differentiate and behave like a zygot to give rise to whole new plant. |
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Term
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Definition
mass of undifferentiated cells
-can propagate forever |
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Term
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Definition
| differentiated cells -> callus -> form roots/shoots -> new plant |
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Term
| what's tissue culture good for? |
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Definition
-clone plants with nice traits
-develop new genotypes with desire traits (genetic engineering) (cloning)
-study genetics of somatic cells instead of germ cells |
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Term
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Definition
-auxillary bud: meristematic cells left behind to later form branches
-zone of division
-zone of elongation (and some differentiation)
--zone of differentiation away from meristem |
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Term
| cell expansion and enlargement |
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Definition
turgor pressure causes the actual expansion
H+ ions are pumped into cell wall by H+ ATPases (acidified)
1. weakens interactions between wall components (pectins cellulose etc.)
2. stimulates expansins (proteins involved in wall loosening) |
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Term
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Definition
occurs after cell division and enlargement
-one cell stays meristematic
-one cell differentiates
asymmetric cell division can be involved in differentiation i.e. trichomes. |
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Term
| genetic basis for differentiation |
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Definition
-some genes up/down-regulated
-some genes are actually specific for contolling development |
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Term
| patterns of gene expression |
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Definition
spatial -
1. every cell type has housekeeping genes
2. cell specific genes
3.tissue specific genes
4. organ specific
temporal
1. constitutive - on all the time
2. regulated/modulated
-inducible
-repressible
-rhythmic ex. circadian |
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Term
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Definition
| genes inserted into plasmids w/ antibiotic resistance which are inserted into bacteria, bacteria w/ genes live, DNA is purified |
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Term
| differentiation via gene expression |
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Definition
developmental regulation of genes occurs at
-transcription almost always
2. mRNA stability and degradation
3. translation
4. protein stability/degradation
5. post-translational modification (phosphorylation etc. |
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Term
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Definition
permit genome-wide expression studies
mRNA -> cDNA -> clone and partially sequence many of them -> identify by sequence homology
mRNA -> cDNA w/ fluorescently labeled nucleotides
digest RNA to generate single-stranded cDNAs
hybridize to microarray & wash away unbound DNAs
lets you determine what genes are being expressed
-different samples can be ran at the same time with different colors.
if two different parts of a plant run the same colors the gene might be involved in development |
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Term
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Definition
basically are able to see what genes are turned on - mostly in organs
however new technology lets you look at cells |
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Term
| finding regulatory developmental genes |
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Definition
1.identify/isolate developmental mutants of a model genetic organism
2. map and clone the gene
3. study gene's structure, function and regulation |
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Term
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Definition
-control overall body plan of an organism
-have common homeobox sequences
-transcribed/translated into homeodomains in proteins = DNA-binding domains - act as transcription factors
*can really fuck things up ex. a fly with legs for antennae
in plants, determine organ identity |
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Term
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Definition
slide 25 growth
shows 3 classes of homeotic genes
sepals, petals, stamens, carpel/pistils
there is overlap between homeotic gene expression. |
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Term
| developmental response to environment |
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Definition
-simpler and slower than animals
-external: light water gracity nutrients touch heat/cold
-internal: plant hormones enzymes chemicals and cell to cell contact |
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Term
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Definition
-need prolonged cold period for germination
-like seasons
ex. cabbage won't flower without being vernalized. it can grow for years without. |
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Term
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Definition
roots grow toward source of gravity
-growing towards earth usually means water too
-they are NOT "seeking" water |
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Term
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Definition
change in rate of growth of one side vs. other OR rapid change in turgor to fold leaves
ex. tendrils on a plant spiral growth and also branches that touch develop more bark |
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Term
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Definition
photomorphogenesis - controls development (ex. leaves greening)
phototropism - controls direction of growth to or from light source
photoperiodism - daylength
short day plans - flower in fall when days are short
long day - early spring when days lengthen
day neutral - light has nothing to do with it |
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Term
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Definition
| when light controls plant development. ex. the greening of leaves. |
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Term
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Definition
| controls direction of growth (toward or away from)a light source |
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Term
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Definition
photo period - morphology in response to day length
long and short day plants fall/spring |
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Term
| developmental responses to light |
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Definition
all responses
1. photoreceptor detects light
2. signal transduction system - 2ndry messengers transmit and amplify signal
3. response system - gene activation (or de-repression)
responses are to
-presence
-quality
-duration/quantity
-direction |
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Term
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Definition
chlorophylls, carotenoids and xanthophylls
anthocyanins: color and attractiveness. possibly photoprotection. |
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Term
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Definition
-absorbs red/far-red light
-helps determine daylength and sading
influences
-stem elongation in young seedlings
-seed germination
-promoting stomatal opening
-promoting leaf development (seasonal)
proplastid -> etioplast -> chloroplast
2 FORMS
-red 660nm -usually inactive form
*usable for photosynthesis
-far red 730nm -usually active form
*longer wavelength light passes through shading leaves.
*more hydrophobic - binds membranes better see slide 39 growth
*interconvertable
shaded plant gets higher ratio of far red:red. stem grows more. |
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Term
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Definition
absorbs blue light (350-450)
-chromophore - a flavin FAD slide 41 growth
deficient in blue light = stimulated leaf development
-major role in flowering and circadian rhythms |
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Term
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Definition
-absorbs blue light
-phototropism towards light
-chloroplast migration: in bright light the chloroplasts move to side walls
-similar to cryptochrome. flavin for photoreceptor butalso has kinase activity
-LOV domains - in genes responding to light, oxygen or voltage |
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Term
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Definition
| in genes responding to light, oxygen or voltage |
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Term
|
Definition
slide 43
GTP --> vGMP + 2Pi
-viagra inhibits cGMP-phosphodiesterase so cGMP buils up and relxes smoot muscle allowing more blood flow |
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Term
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Definition
common 2ndry messenger in plants
-binds 4 Ca2+ ions and becomes activated
-Ca2+ very low levels in cytoplasm. tightly regulated. |
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Term
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Definition
-slide 45
-alpha subunit GTPase (binding/hydrolyzing)
-activates when binds to GTP and beta/gamma subunits leave. aplha moves to target. GTP hydrolysis releases it from binding to target. reforms with subunits. |
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Term
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Definition
-chemical produced in one part of the body that has effects on another part
-typically growth related in plants
-act in small amounts. potent.
-mostly released to the phloem
-target cells have hormone receptors
-binding triggers response
they are a switch not a blueprint
in plants
-usually simple organic molecules
-can function alone or with others
-some are transported and some work where produced
-different tissues respond differently to the same hormone. |
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Term
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Definition
-1st plant hormone discovered.
-triggers phototropism and is now known as phototropin
-causes bending toward especially blue light
-studied by darwin. determined sensing tissue at tip of coleoptile
-peter boysen-jensen. it must be a diffusible chemical signal
-fritz went: the chemical will even work in darkness.
-went and fritz: shaded side must produce auxin causing elongation and thus bending.
-winslow briggs: auxin destruction vs. redistribution. redistribution is the right one. |
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Term
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Definition
auxin
auxins always have carboxyl group. they are composed of at least one aromatic ring. occasionally an imine. occasionally chloride substituents. |
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Term
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Definition
cytokinens
variations on adnenine - two imine rings; 5 and 6 membered. w/ substituents. |
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Term
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Definition
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Term
|
Definition
|
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Term
|
Definition
one single compound that generally is a growth inhibitor
-produced in leaves and moves to other parts
-roots send it to prepare for drought
1. promotes dormancy in seeds
2. promotes responses associated with plant stress; closes stomates
-wilting induced mesophyll cells to produce ABA
-misnamed: not always involved in leaf abscission. |
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Term
|
Definition
promots cell elongation
-coleoptile
-other places
-causes bending toward the sun
-produced in shoot apex (leaf tips etc) and moves through plant. |
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Term
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Definition
auxin bind to a receptor and activates pumps. H+ out and K+ in to maintain turgor pressure. ph drops and breaks bonds in wall matrix to loosen cell wall.
*pH also activates EXPANSINS in cell walls. |
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Term
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Definition
| enzymes that are apparently shaped like pac man and break down the hydrogen bonds between cellulose and hemicellulose |
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Term
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Definition
auxin is involved in gravitropism.
shoot to sun, root to run... i'm going to quit school to write poetry. source of gravity.
-statoliths in statocytes trigger auxin redistribution. (auxin on lower side of root actually inhibits cell elongation so root bends down. |
|
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Term
| how do plants orient themselves to gravity? |
|
Definition
statocytes in root cap
-contain amyloplasts which have staoliths that sit at the "bottom" of the cell. |
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Term
|
Definition
auxillary bods delay outgrowth until they are some distance from the shoot apical meristem.
-auxin from shoot apical meristem INHIBITS outgrowth of axillary buds. (cytokinins promote bud outgrowth.) |
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Term
|
Definition
-basipetal movement in spring causes vascular cambium to become active cell division and differentiation. especially xylem.
-leaflet initiation in compound leaves
-female gametophyte patterning
-cell fates in regions of plant embryos
*NOTE auxin is not responsible for the various responses. it's the target's reaction. |
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Term
|
Definition
-helps cell determine its relation to other cells
-helps cell determine where it is relative to shoot apex
-critical in determining plant morphology. especially in changing conditions. |
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Term
|
Definition
purines - variations on adenine ex. zeatin and isopentenyl adenine and kinetin (synthetic)
-produced in root apical meristems & transported to shoot system and axillary buds. |
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Term
|
Definition
-promote cell divisions in target cells in apical meristem and maintenance of meristems
-promotes axillary bud outgrowth
-balance root/shoot growth. roots have to grow to support shoots
-seed development. found in endosperm and cotyledons
-delay senescence in leave
-stimulating differentiation & activity of vascular cambium (with auxin)
-root nodule formation
-work al lot with auxin
ex tobacco pith
*high aux:cyt = stimulation of roots
*low aux:cyt = stimulation of shoots |
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Term
|
Definition
large number
-produced in uppermost leaves. transport to res of plant. |
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Term
| functions of gibberellins |
|
Definition
-cause cell division and stem elongation
-growth and differentiation in vascular cambium w/ auxin and cytokinin
*phloem differentiation
-transition from vegetative to reproductive state in some plants
-significant role in seed germination
*stimulate embryo to renew development
*increase a-amylase levels (breakdown starch
*activate a-amylase
-basically embryo saying feed me to the rest of the seed |
|
|
Term
| how do gibberellins work? |
|
Definition
-promote elongation via expansins. DIFFERENT from auxin. cells that don't work with auxin do with G's
*expansins stimulate xyloglucan endotransglycosylase which cuts hemicullulose in half.
-modulate gene espression. binds to a-amylase gene to initiate the production of. a de-repressor
- |
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Term
|
Definition
-one compound.
-growth inhibitor
-produced in leaves
-not exactly sure what it does |
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Term
|
Definition
-dormanct in seeds (antagonist of GA?)
-promotes responses associated with plant stress
*closes stomates: wilting induces mesophyll cells to produce ABA. tells guard cells to close stomates.
-DOES NOT always play a role in abscission. hardly ever. misnamed. |
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Term
|
Definition
-a gas. volatile.
-acts locally. |
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Term
|
Definition
-fruit ripening: positive feedback. the more ripening the more gas and so more ripening.
ripening: see slide 79 growth
-leaf abscission: decrease in aux. in shoot = ethylene production in leaf abscission zone.
*eth inhibits auxin transport
*signals degradative enzymes |
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