Metabolites Flashcards
what are the 2 categories of metabolites
primary metabolites
secondary metabolites
what are primary metabolites
compounds common to all plants
generally necessary for basic growth, plant cant live without them
what are secondary metabolites
compounds useful to plant but not required for growth
involved in defense and plant to plant communication
how do we distinguish the role of a particular compound in a plant
by generating a null mutant
what is a null mutant
individual which has been mutated so that it no longer expresses the compound of interest
if it fails to grow, compound is primary
what are 4 pathways of plant communication
root-to-root
touch
volatile organic compounds
sound
what is root to root communication
chemical signals are relased by roots which cause changes in adjacent plants
how does root to root communication work
something happens to one plant
plant expresses stress and near plant produces a signal to warn the next plant
what is touch communication
physical contact with specific factors triggers a cascade of signals inside plant
what can touvh plant
other plants
harmmful animals
neutral animals
how does touch communication work
it is context specific
different signals
what happens when plant senses rain by touvh
plant panics
cascade of signals to heighten immune system
water on leaves can start infestation of a pathogen
what is volatile organic compounds communication
compounds released on the surface of the leaf tissue
compounds release in gas form and travel to adjacent plants
role of volatile organic compounds in pest defence
attacks can tigger plant to release VOC and warn adjacent plants of same species
what is sound communication
cellular division in plant growth makes noise
what are the 2 most common mechanism in chemical warfare
herbivore deterrence
allelopathy
what is herbivore deterrence
chemical which make plant tissues upalatable
traits of chemical deterrence
spas contain a mix of toxic compounds
contact with sap causes ozzing blistring rashes
eating fruit causes life threatening tightening of airways
what is capsaicin
secondary metabolite produced by capsicum genus of peppers
responsible for burning flavor of hot peppers
what is allelopathy
plants produce range of secondary metabolites specifically designed to negatively impact growth of other plants
what are the 2 types of alleopathy
active
passive
what is active allelopathy
plant spends energy to synthesize secondary metabolites and directly secrete them into the environment
what is passive allelopathy
secondary metabolites are released as the dead plant material is broken down by decomposers
what are plant hormones responsible for
regulation of every growth process throughout the plant
important signalling molecules
what are the 5 major groups of plant hormones
auxin cytokinin gibberellic acid abscisic acid ethylene
role of auxins
maintaining apical dominance
tells plant apical bud is stll present
main site of biosynthesis of auxins
apical terminal bud
other roles of auxins in the plant
- involved in growing plant tissues towards the light by accumulating in regions of plant that are shadded
- cellular differentiation: helps determine fate of cells produced by meristematic tissues
- adventitious root formation: auxin placed on a cut stem stimulates growth
role of cytokinins in plant
work in conjunction with auxin to regulate plant development
inhibited by auxins
main site of biosythesis of cytokinins
roots
other roles of cytokinins in the plant
- promote lateral bud growth
- help development of embryo
- delyas leaf senescence(death)
effect of auxin/cytokinins in the shoot
- cytokinin promotes lateral bud growth
- lateral buds open and race to become apical shoot
- longer and larger stem begins auxin synthesis
- other shoots begin to decrease growth
- new apical shoot is born
role of gibberellic acid in plants
cell elongation
breaking dormancy
flowering
leaf and fruit senescence
main site of biosynthesis of gibberellic acid
produced locally in tissues as needed
role of abscisic acid
initiation and maintenance of seed dormancy
signaling molecule in stomatal closure
slowing growth
main site of biosynthesis of abscisic acid
throughout the plant
effect of gibberellic/abscisic acid in seed dormancy
- build up of abscisic in seed stop growth
- abscisic gradually dissipates and when gone gibberellic can help shoot elongation
what is the main role of ethylene
fruit ripening
stimulate leaf senscence
main site of biosynthesis of ethylene
throughout the plant
what is the pathogen defence in animals
immune system is driven by white blood cells
what is the pathogen defence in plants
secondary metabolite synthesis is driven by hormone signaling
hormone signaling/secondary metabolites make up the biosynthetic pathways that are responsible for a plants pathogen defence system
what is an induced defence
defence synthesized in direct response to pathogen attack
what is constitutive defence
compounds always present in plant
what are the types of induced defense
systemic acquires resistance
hypersensitivity response
what is systemic acquired resistance
entire plant synthesizes and expresses defence compounds even if attack is in one area
signaled by plant hormones and carried out through secondary metabolites
what is hypersensitivity response
plant undergoes programmed cell death to protect itself
host contains infection by selectively killing its own cells
