Abstract
Chitinase specific activity was measured spectrophotometrically in wheat leaf tissues during the compatible and
incompatible interactions withPuccinia striiformisf. sp.tritici, the causal agent of yellow rust disease. The wheat
cultivar, Federation∗4/Kavkaz, was inoculated with virulent (134E134A+) or avirulent (4EOA+) races ofP.
striiformisf. sp.triticiin the first leaf stage. The results showed that chitinase activity pattern was similar in both
compatible and incompatible interactions up to 72 hrs after inoculation. However, the specific activity increased
rapidly in the incompatible reaction thereafter. In susceptible reaction, chitinase activity gradually declined after
72 hrs post-inoculation reaching a level similar to that in the control plants two weeks after inoculation. Chitinase
specific activity in resistance response was at least three times greater than that in the susceptible reaction two
weeks
following the inoculation. Electrophoresis of native polyacrylamide gel impregnated with 0.1% (w/v) glycol chitin
as the substrate revealed the presence of eight chitinase isoforms with relative electrophoretic mobility (Rm)values
ranging from 0.11 to 0.64 in the resolving gel.
Key words:chitinase,Puccinia striiformisf. sp.tritici, resistance, wheat; yellow rust disease