week 8 - plant signalling Flashcards
what is thigmonasty
response to touch
what does thigmonasty allow
touch allows ion flow into outer cells of pulvini
up regulation of aquaporin and H+ -ATPase (proton pump)
turgor increase/ decrease due to osmosis
what is the role of the xylem
water moves from soil to atmosphere through hollow dead xylem cells
what is the role of the phloem
sugars made from photosynthesis (and other molecules) move from their source to sinks (non-photosynthetic tissues) through the phloem
how do signals move in the xylem
signals from drought-stressed roots cause guard cells to close
other xylem-borne signals convey information about nutrient availability and soil-microbes
what is the coordination of root and shoot
when leaves are phosphate-limited, microRNA (miR399) moves through the phloem to the root and promotes phosphate uptake
how is reproduction promoted
under appropriate day-length conditions the protein flowering locus t (FT) and its orthologs move from leaves to the shoot apex via the phloem, to promote the transition to reproductive growth
what is the ROS
respiratory burst oxidase homolog
what is the role of the ROS wave
it accompanies other signals to alert the cells and tissues of stress
how do plants respond to their environment
they use electrical, hydraulic and chemical signalling
examples of electrical signals
action potentials
slow wave potentials
system potentials
examples of hydraulic signals
changes in turgor pressure
pressure waves
mass flow
examples of chemical signals
reactive oxygen species
Ca+/K+/anion signalling
volatiles
phytohormones
MAP-kinase
inositol triphosphate
what are the steps of signal perception and transduction in plants
perception -> transduction -> response
how does stress perception occur
stress perception can occur by sensors/receptors in different organelles
