plant defense Flashcards
surrounded by an enormous member of potential enemies.
plants
is a principal constituent of the cuticle
cutin
forms at sites of leaf abscission and in areas damaged by disease or wounding
suberin
is a principal component of the outer cell walls of all underground organs and is associated with the cork cells of the periderm
suberin
are not macromolecules, but rather complex mixtures of long-chain acyl lipids that are extremely hydrophobic
waxes
form barriers, between the plant and its environment, that function to keep water in and pathogens out.
Cutin, suberin, and their associated waxes form
They protect plants against being eaten by herbivores and against being infected by microbial pathogens
Secondary Metabolites
They serve as attractants (smell, color, taste) for pollinators and seed-dispersing animals
secondary Metabolites
They function as agents of plant-plant competitions and plant microbe symbioses
secondary Metabolites
These metabolites are relevant to agriculture; increase reproductive fitness by warding of fungi, bacteria, and herbivore.
secondary Metabolites
constitute the largest class of secondary products.
terpenes
derived from the union of five-carbon elements that have the branched carbon skeleton of isopentane
terpenes
The basic structural elements of terpenes are sometimes called
isoprene units
an important group of plant hormones, are diterpenes
gibberellins
are triterpene derivatives that are essential components of cell membranes, which they stabilize by interacting with phospholipids
sterols
are tetraterpenes that function as accessory pigments in photosynthesis and protect photosynthetic tissues from photooxidation
red, orange, and yellow carotenoids
is a C15 terpene produced by degradation of a carotenoid precursor.
abscisic acid
Many plants contain mixtures of volatile monoterpenes and sesquiterpenes, called
essential oils
first isolated from the common fern, Polypodium vulgare, are a group of plant steroids that have the same basic structure as insect molting hormones
phytoecdysones
are glycosides (compounds containing an attached sugar or sugars) that taste bitter and are extremely toxic to higher animals. This can be found in foxglove flower (Digitalis)
cardenolides
may interfere with sterol uptake from the digestive system or disrupt cell membranes after being absorbed into the bloodstream.
saponins
Highly Complex Phenolic
Macromolecule
lignin
is found in the cell walls of various types of supporting and conducting tissue, notably the tracheids and vessel elements of the xylem
• Provides mechanical support
lignin
protective functions in plants. Its physical toughness deters feeding by animals, and its chemical durability makes it relatively indigestible to herbivores
lignin