Characterisation of potential antigen(s) of Tilletia indica teliospore walls to develop a specific immunoassay for Karnal bunt detection

Abstract

Characterisation of potential antigen(s) in the teliospore wall of Tilletia indica, the causal agent of Karnal bunt (KB) of wheat (Triticum aestivum) is necessary to generate specific immunoprobes for the development of reliable immunodiagnostic procedures. The intact teliospores of KB were used to generate anti-teliospore antibodies for the development of microtitre ELISA. The anti-teliospore antibodies cross-reacted with Tilletia foetida, Puccinia recondita and Puccinia striiformis suggesting that these species share one or more antigenic components. These antibodies recognised two unique immunoreactive bands of molecular weight ~34 kDa and ~15 kDa present in the spore wall fraction of T. indica after western blotting. The periodate treatment alone and sequential treatment of periodate followed by trypsin lost the immunoreactivity partially and completely, respectively. This suggests that cross-reactivity among bunt and rust of wheat fungal pathogens is most likely due to peptidal/oligosaccharide epitopes overlapping the spore wall's glycoprotein.

Keywords:

• Karnal bunt (KB)
• teliospores
• polyclonal antibodies
• cross-reactivity
• ELISA