L19 Flashcards
Central Zone
Meristematic activity
Indeterminate
undifferentiated
Unlimited number of
cell division
Peripheral Zone
Lateral organ formation
Determinate
differentiated
Limited number of
cell division
SHOOTMERISTEMLESS1 (STM1)
A master meristem identity gene
genes central zone
STM, WUS
genes peripheral zone
CLAVATA1, 3
PHYLLOTAXY
phyllon (leaf) + taxis (arrangement)
fibonacci #
137/8 degrees
How is phyllotaxy determined?
Inhibitory field hypothesis
Biophysical hypothesis
General control of genes- meristem and lateral organ genes.
Inhibitory field hypothesis
Temporal and moving signal(s) from the emerging leaf primordium inhibits new leaf primordium formation in the to the neighbouring area.
Action of “expansins”
Loosen the cell wall
Primordia can be induced by the application of
expansin
Auxin is a plant _______ that controls many aspects of ____________
hormone
growth and development.
Auxin (IAA) is a______ acid. At the low pH of cell walls, it is __________ (IAAH), allowing it to move through the ___________. In the less acidic cytoplasm, it loses the_______, becomes charged (IAA-), and cannot exit the cell by_______ through the plasma membrane.
weak
protonated and uncharged
plasma membrane.
proton
diffusion
The____ protein is an auxin efflux carrier, transporting_____ auxin back out of the cytoplasm.
PIN1
charged
The subcellular localization of PIN proteins can be______ and_______ between cells, causing directed auxin transport.
polar
coordinated
