Open AccessA Chitinase from Tex6 Maize Kernels Inhibits Growth of Aspergillus flavus
Author(s) -
Kenneth G Moore,
Michael Price,
Rebecca S. Boston,
Arthur K. Weissinger,
Gary A. Payne
Publication year - 2004
Publication title -
phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.264
H-Index - 131
eISSN - 1943-7684
pISSN - 0031-949X
DOI - 10.1094/phyto.2004.94.1.82
Subject(s) - chitinase , aspergillus flavus , biology , aflatoxin , microbiology and biotechnology , biochemistry , sodium dodecyl sulfate , polyacrylamide gel electrophoresis , fungi imperfecti , enzyme , gel electrophoresis , enzyme assay , botany , food science
The maize inbred Tex6 has resistance to colonization and aflatoxin accumulation by Aspergillus flavus. A protein inhibitory to growth of A. flavus has been identified from aqueous extracts of mature Tex6 seeds. This study reports the purification of a chitinase associated with this inhibitory activity to electrophoretic homogeneity and the further characterization of its properties. The inhibitory protein, which has an M r of 29,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is an endochitinase that is also capable of exochitinase activity. The enzyme has an optimal pH of 5.5 and a temperature optimum of 45°C. Chitinase activity in maize kernels peaked approximately 36 days after pollination. The Tex6 chitinase purified in this study is capable of inhibiting the growth of A. flavus by 50% at a concentration of 20 μg/ml. Our data indicate that chitinase activity in Tex6 kernels makes a major contribution to the antifungal activity in this maize genotype. Partial peptide sequence of the chitinase showed it to differ from previously reported chitinases.