Plant Herbivore Defense
How are plants able to defend themselves against
herbivores using chemicals? Are any of these chemicals useful for
The following should be helpful:
Anthony Brach Ph.D.
Plants make a myriad of compounds that deter potential herbivores from
eating them. These compounds can make the plant distasteful or be
downright toxic to the herbivore. Often, the compounds are stable and
nontoxic when the plant is intact. The compounds are converted to a
more toxic or deterrent form when the herbivore begins to eat the plant.
The fruits and vegetables we eat are often poor examples of the toxicity
that plants normally have because we breed the plants to have reduced
levels of toxins in the parts of the plant we want to eat.
Many of these compounds have broad effects on herbivores of all sizes
(from nematodes to deer) and even microbial pathogens. Plants are the
source of many chemicals that we consider medicines.
Jim Tokuhisa, Ph.D.
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Update: June 2012