The
data obtained in this paper show that two
constitutive endochitinases (Chit I and II) are present in
rice callus,
and that treatment with a chitin derivative
results in induction
of an additional enzyme (Chit III). It
has been reported that two or more chitinases occur in
most higher plants, and
that some of them are induced in
response to pathogen infection, treatment with a chitin
derivative or cell-wall preparation
of a pathogen, ethylene
application, abiotic stress, or ageing.
3.16.1 7) We have found
that Chit III is also induced in rice callus inoculated with
Alternaria alternata Japanese pear pathotype. Physiologi
cal functions
of the three chitinases in defense reactions in
rice will be reported elsewhere.