plant cell signaling Flashcards
function of the xylem
transports water and inorganics up from roots
function of the phloem
transports soluble organic compounds down
apical meristem
growth region
functions of auxin
cell expansion, meristem formation and promotes apical dominance
functions of cytokinin
promotes cell division, delays senescence, suppresses apical dominance and promotes abscission
apical dominance
main central stem of the plant is more dominant than the lateral branches
functions of Gibberellin
promotes germination, promotes cell expansion, promotes vegetative to floral transition
functions of Brassinosteroids
promotes cell expansion, promotes vascular differentiation, promotes senescence and suppresses defense response
functions of jasmonic acid
herbivory defense signal, abiotic stress and is volatile so can signal to other plants
functons of strigolactone
shoot branching, abiotic stress and mycorrhizal fungi attractant
what are the 4 perception mechanisms for plant hormones
1) Ubiquitination
2) histidine kinase
3) PP2C modulation
4) receptor kinase
how is Auxin perceived through E3 ubiquitin ligase
Direct molecular glue - bind directly to ubiquitin ligase then to transcriptional regulator which is then degraded
how is gibberellin perceived through E3 ubiquitin ligase
indirect molecular glue - they are perceived by a receptor, the receptors confirmation changes upon binding forming a new binding site for DELLA transcription factor. DELLA binds to GA and is recognized by an other F-box protein which then finally leads to the ubiquitylation of DELLA .
how are strigolactones perceived through E3 ubiquitin ligase
allosteric effect - They bind to D14 enzyme which slowly degrades it until its conformation changes
the conformational change recruits F-box protein
this recruits transcriptional factor which is then degraded