Submitted to: International Institute For Beet Research Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 20, 1995
Publication Date: N/A
Interpretive Summary: Cercospora leaf spot is the most serious foliar disease affecting sugarbeet. Sugarbeets synthesize the proteins chitinase and glucanase in response to infection by the fungus. These two proteins are thus suspected in a resistance reaction by the plant. The objective of this study was to isolate and purify these proteins and then to raise antibodies against them. These antibodies might then promote a selection screen for development of Cercospora resistance.
Technical Abstract: The PR (pathogenesis related) proteins chitinase and glucanase were isolated from leaf spot resistant (LSR) leaf tissue. A gel containing 12% polyacrylamide, and 2.67% bisacrylamide was used for optimal separation of contaminating proteins from the chitinase fraction. The apparent molecular weight of chitinase and glucanase as determined by SDS-PAGE was 34 kD and 26 to 29 kD, respectively. Glucanase isolated by affinity chromatography had an isoelectric point of 4.9. The specific activity of the fraction before chromatography as 8 mMol reducing sugar min-1 mg-1 protein and the fraction eluted off the column had a specific activity of 142 mMol reducing sugar min-1 mg-1 protein. Proteins with these molecular weights and/or activities have not been previously reported and may be linked to Cercospora beticola field resistance.