insecticidal allelochemicals Flashcards
allelochemicals allow for different relationships between organisms. what are they?
mutual benefit
competition
allelochemicals upregulated by
UV radiation
day length
stress
elicitors (microbe attack)
T/F: all allelochemicals are safe
F: most but not all
how plants response to insect heerbivores
- tolerate assult, makes difficult for herbivore, or kill herbivore
- antixenosis or non-preference, tolerance and antibiosis
plant resistance mechanisms to insect herbivores could be ______ or _______
constitutive or induced
antibiosis definition
deleterious impact on overall well-being of insect herbivores
antibiosis impacts through ______ _____ disruptions. can be ___ or ____
life cycle
mild or fatal
constitutive resistance
plant has INHERITED ability to defend itself
induced resistance
arises due to attack by herbivores, disease or abiotic factors.
made from individual life experience of that plant
constitutive and induced resistance can be direct or indirect. what does that mean?
direct resistance - morphological traits and secondary metabolites of plants respond to insect herbivores
indirect resistance - rely on insect’s natural enemies for protection (send pheremone signal to spider that eats insect herbivore)
herbivore induced plant volatiles (HIPVs) produced due to _____ _____ and lead to _____ resistance
insect damage
indirect resistance
HIPVs attract ________ to reduce the ____ _____
predators
plant damage
anti herbivore compounds are ____ metabolites and suppress _____ -______
secondary
insect-herbivores
HIPVs divided into subgroups
nitrogen compounds including alkaloids, cyanogenic glycosides, terpenoids and phenols
diversity of angiosperms in _____ period is associated with the increase in ______ of____
with evolution, selected processes resulted in defence against ___-____
this is co-evolution is in ______ and ______
Cretaceous
speciation of insects
insect herbivores
vascular plants and insects
insect herbivores vary in their ability to ….
this speciation drives the evolution of different ____ plants and ____ plants
cope with multiple plant defense mechanisms
host plants and food plants
plants also developed resistance mechanisms over time to…
reduce the damage caused by insects
examples of plant response to insect herbivores (primary morphological features).
what do they do?
thorns, spikes, wax, wall thickness, etc
they disrupt movement, feeding and reproductive success of insects
_____ herbivores cope with plant defense compounds better than ____ herbivores
specialist
generalist
specialist herbivores are not affected by..
how are specialist insects survive plant defenses?
… defense mechanisms of host plants
developed physiological adaptations
glucosinolates are in higher concentration of plant ______ than _____. this is why catapillars feed on the plant’s _____
flowers
leaves
flowers
specialists have a ________ to cope with the _____ ____ of the plants
physiological adaptation
defense mechanisms
T/F: only specialists can overcome digestibility reducers
F: specialists AND generalists can overcome digestibility reducers
digestibility reducers affect all insects but could be adapted by _____
specialists
_____ number of insects are immue to harmful effects of plant toxins
small
specialists sequester toxic chemicals from plant and use them to
protect themselves from predators
general mechanisms for plants of the same species to respond to herbivores are _________
heritable
_____ insects are more sensitive to plant toxins than _____ insects
generalist
specialists
which gets induced first, direct or indirect response?
direct response first
indirect response if no direct response
primary or secondary metabolites make defense shit (ex. insecticides)
secondary
infested plants have higher levels of ____ proteins compared to non-infested plants
defense
there is an insect infestation in plant. ____ defense metabolites produced first. ____ defense metabolites produced second, for example….
small
large, terpenoids
plant allelochemicals can act as
repellents
deterrents
growth inhibitors
mortality
what types of strategies did insects evolve to cope with plant toxins
avoidance, excretion, sequestration and degradation
coevolution of plant allelochemicals and insect coping strategies driven by
competition
neem based toxins show ____ effects on insects
aversive
terpenes from neem have stimulatory effects on ______ receptor cells in larvae
chemosensory
monoterpenoids show ____ pattern and are toxic to _____
seasonal pattern
beetles
neurotoxic effects on insects
hyperactivity, hyper-excitation, rapid knock down and immobilization
insect herbivore stategies to cope with toxins:
- use carbs to mask toxins
- diet exposure to induce P450 production
- diet exposure to specific secondary compounds
types of alelochemicals as insecticides
SATGTP (shakir and thomas got true pizazz)
salicylic acid
alkaloids
tannins
glycosides
terpenoids
phenols
+lignin
alkaloids: how they affect insects
taste
affect neurotransmission, disturb cell membrane/cytoskeleton and cause leaky cells
taste bitter to humans
Pyrrolizidine alkaloids:
____ repellents
toxic to ____ ____ of generalist insect-herbivores
examples
induced due to
mechanism
feeding repellant
intestine microbes
jacobine and erucifoline
root damage
exist as N-oxide in root (safe), degrades into tertiary compound in insect gut = toxic
nitrogen alkaloids examples
caffiene, morphine and nicotine
another nitrogen alkaloid example = Theobromine
used to make ______
used in medicine for
caffeine
diuretics, myocardial stimulants, vasodilator, smooth muscle relaxants
nitotine alkaloid:
effect on insect
repels ____, whereas doesn’t affect _____
physical damage of tobacco leafs releases ______
paralysis and death
spiders, not catapillars
green leaf volatiles (GLVs)
nitrogen alkaloid: plants in nightshade family produce _____, a ____-toxic alkaloid and ____ stimulant. This produces _____ and stored in ____ when insects chew leaves
atropine
neurotoxic
cardiac
nicotine
vacuoles
there are __#__ terpenoids
20,000
terpenoids::
in the __ canals of bark ____, then distributed though roots and shoots
can mount indirect defense via attracting ______ of insect herbivores by releasing ____, which attract ______ (predators, parasites, etc)
extremely _____
resin, xylem
enemies , volatiles, beneficiaries
volatile
conifers increase their concentration of ______ and ______ when attacked by infestations of insects
monoterpenoids and sesquiterpenes
pyrethrins (monoterpenoid) produced by _____ plants are _____ to insects
chrysanthemum
neurotoxic
the terpenoids ____ and _____ produced by mint plants. stored in ____ of the epidermis
menthol and menthone
trichomes
what monoterpenoid spices are safe for humans but toxic to insects
mint, basil, oregano, rosemary, sage and savory
terpenoids from orange and neem oil are biopesticides that controls what insect
aphids
T/F: diterpenoids and carotenoids are made in mevalonic acid pathway in plastid organelles
FALSE: not made in that pathway, but are made in plastid organelles
diterpenoid: _____ toxin inhibits ___ channels in thrips
romedotoxin
sodium
the triterpenoid “limonoid” is an insect _____
insect deterrents
saponins are triterpenoids that messes with what?
disrupts cell membrane via messing with cholestrol, which causes cell death
phenols made in ____ pathway, has ____ properties, disrupts insect _____ system.
shimik acid
antiseptic
endocrine
how do phenols affect aphids; explain mechanism
soluble part crosses intestine barrier and located in blood. toxic effects that cause oxidative stress.
tannins prone to oxidization in insects under high ___ conditions, like radicals, that cause toxicity at higher concentrations
alkaline
the tannins silica and lignin are found in plant ___ walls, are not ____ by insects. cause damage by…
cell
digestable
grinding down the mandible of insects, DNA damage
insects developed coping strategies to tannin toxicity via…
this lead to
avoidaance, excretion, sequestration and degradation of tannins
co-evolution and co-diversification
jasmonic acid and ______ acid are similar defenseive response to ___ _____ by aphids
salicyclic acid
sap sucking
resistance to salicyclic acid though activity of _____ and _____ enzymes
NPR1
digestive enzymes
lignin provides ____ to ____ _____ and ____ to biotic and abiotic stress
structure to cell walls
support
lignin provides a ____ ____ against insect attacks. so plant tissue ____ (high lignin) reduces insect damage to plants
physical barrier
toughness
glycosides converted to _____ ____, which is toxic to ____ herbivores. this is because they have bad ___, increase _____, decrease absorption of ______, delay larval ____
hydrogen cyanide
genearlist
smell
ROS
amino acids
development
allomones definitions
effects are favorable to sender not reciever
repellents definition
turn away insect
locomotor excitants definition
cause hypermotility
suppressants definition
reduce overall activity and impact of insect herbivores
deterrents definition
prevent attacks by insect herbivores
arrestants definition
prevent motility
digestibility reducing definition
negativly affect nutrient uptake and use
toxins definition
posionous
parsnip webworms eat
furanocoumarins
oleander aphids eat
jasmonic acid in milkweek
monarch caterpillars eat
jasmonic acid and salysalic acid milkweed
tobacco hornworms eat
food with nicotine
larvae tradeoff explanation
larvae eat plants with low cardenolide levels because can use cardenolides for antipredator defense.
too much high levels of cardenolides can kill baby larvae
there are two rose plants in waterloo and burlington. a ladybug chews on both. both rose plants release SA. is this constitutive or induced response?
constitutive because roses have default/inherited response mechanism
there are two rose plants in waterloo and burlington. a ladybug chews on both. one rose plants release alkaloids, one rose plants releases jasmonic acid. is this constitutive or induced response?
induced because different responses from diff enviornmental influence/individual life experience of plant. (same plant, diff location, diff allelochemicals bc of diff responses)
alkaloids have what effect on insect diet
cause them to stop feeding
atropine is
poisionous
deltamethrin is a
commercial pyrethroid
A.indica is used as a
biopesticide