stomatal asymmetric division Flashcards
What two cells does the meristemoid mother cell divide into after ACD?
SLGC and meristemoid
What are the lineages of the daughter cells from MMC ACD?
SLGC can either return to stomatal lineage or regress to standard epidermal cell
Meristemoid goes on to be a guard cell
What transcription factor positively regulates stomatal development?
Speechless (spch)
What is the phenotype of a spch- mutant?
Lethal mutation, no asymmetric division and no stomata
Which cells inherit spch after ACD?
Both daughter cells inherit spch, although it is quickly degraded in SLGC
What basic signaling pathway is used to degrade spch in the target cell?
Kinase cascade
What happens when you remove the tyrosine/serine residues from spch, disallowing phosphorylation?
No phosphorylation of spch causes constitutive activation, meaning both cells inherit stomatal lineage
What is the nature of the kinase cascade signaling pathway in stomatal development?
The kinase cascade targets and phosphorylates spch to prevent activation of stomatal lineage genes (negative regulation)
What assay discovered a key negative regulator in stomatal development pathway?
Yeast 2 hybrid assay
What phenotype is caused by yoda- mutant?
massive excess of clustered stomata
What is the result of removing the N terminal regulatory domain from YODA?
results in constitutive activation of yoda, leading to no stomatal development at all
What is the phenotype of the double mutant yoda-/spchts-?
What does this say about the nature of these regulators?
adopts spchts- phenotype.
Means they have an epistatic relationship, with no speechless, yoda has no affect
What is the function of BASL?
BASL is a MAPK scaffold - docks YODA cascade to periphery of SLGC cell
What is the extrinsic signaling pathway that also affects stomatal development?
stomatal linage cells secrete EPF2
Receive in nearby cells by receptor ERECTA (receptor kinase)
Binding of ligand to receptor activates YODA cascade
