Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/12/1999
Publication Date: N/A
Technical Abstract: Isoform patterns of chitinase and beta-1,3-glucanase of maturing kernels of yellow corn (Pioneer 3394) infected with Aspergillus flavus were investigated through polyacrylamide gel electrophoreses (PAGE). Proteins on the SDS gel with an apparent molecular weight range of 23-46 kDa were induced in the kernels by A. flavus infection. From in-gel (native PAGE) enzyme activity assays, three bands corresponding to chitinase isoforms and two bands corresponding to beta-1,3-glucanase isoforms were detected in the infected kernels. One chitinase isoform of 29 kDa was induced only in the infected kernels and another one of 28 kDa was present in both infected and non-infected kernels. They were both acidic based on their migration on an acrylamide isoelectric focusing (IEF) gel. For the beta-1,3-glucanase, one isoform of 35 kDa was present in both infected and non-infected kernels; but another one, 33 kDa isoform, was induced only in the infected kernels. Both acidic and basic beta-1,3-glucanase isoforms were detected in the IEF gel. These results suggest that only particular isoforms of the two fungal degradative enzymes might be involved in combating A. flavus in the maturing corn kernels. These studies might be useful when the two enzymes are applied in corn through genetic engineering to prevent A. flavus infection and aflatoxin contamination.