Development of Immunochemical Techniques for Detecting Karnal Bunt in Wheat

Abstract

The protein profile of Tilletia indica, the causal agent of Karnal bunt, was analyzed by SDS-PAGE and compared to protein profiles of T. barclayana, T. tritici, T. controversa and T. laevis. Based on these results, antibodies were developed against a 64 kDa T. indica protein and used to construct both a microwell sandwich ELISA and a dipstick immunoassay. Both of these immunoassays can detect 1.25 ng/well of purified T. indica protein or 40 ng/well of crude spore extract, distinguishing Karnal bunt from all wheat smuts and, to some degree, the rice smut, T. barclayana. To enhance specificity, an innovative approach to species-specific antibody production was utilized to develop antibodies that discern Karnal bunt from all other fungal species. Using these new antibodies, a Karnal bunt specific immunoassay was developed that has all the attributes of the original Karnal bunt immunoassays and detects Karnal bunt in the presence of wheat. This is the first report of immunochemical diagnostic tools that will aid in controlling the spread of this wheat pathogen by accurately and efficiently detecting Karnal bunt teliospores in wheat.

Keywords:

• Immunodiagnostics
• Karnal Bunt
• Elisa
• Tilletia Indica
• Immunoassay