INDUCTION OF A WHEAT DEFENSE GENE BY HESSIAN FLY LARVAL FEEDING

¹ USDA-ARS-MWA, Crop Production and Pest Control Research Unit, W. Lafayette, IN 47907-1158

² Department of Entomology, Purdue University, W. Lafayette, IN 47907-1158

Feeding of virulent Hessian fly larvae results in stunting and other dramatic physiological changes in wheat seedlings. Although gross morphological changes in the plant are not apparent during the gene-for-gene interaction with avirulent larvae, systemic induction of wheat genes does occur. The expression of one of these genes, Whi-1 (wheat Hessian fly induced), increased four fold in resistant leaf blades during the first three days of attempted larval feeding at the crown of the plant. The timing of Whi-1 gene induction coincided with early events of induced resistance and is similar to induction kinetics of defense genes involved in plant resistance to microbes. Whi-1 shared derived amino acid sequence homology with jasmonate-induced stress proteins and with the jacalin-related lectins, suggesting a role in induced defense against insect attack.