Fatty acid hydroperoxide lyase (HPOL) is an enzyme that cleaves fatty
acid hydroperoxides to form a short chain aldehyde and an oxo-acid. Th
e enzyme is widely distributed in the plant kingdom. Because short cha
in aldehydes have fungicidal activity and can act as repellents of cer
tain insects and attractants for insect predators, HPOL is thought to
be involved in plant defense mechanisms. Recently, HPOL has been purif
ied from several plants and its biochemical properties determined. Fur
thermore, molecular cloning of an HPOL gene from bell pepper has been
accomplished. Determination of the primary amino acid sequence showed
that HPOL defines a novel subfamily of cytochrome P450s.