Russian wheat aphid-induced protein alterations in spring wheat

The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has become a pe rennial, serious pest of wheat (Triticum aestivum L.) in the western United States. Current methodologies used to enhance RWA resistance in wheat germ plasm could benefit from an understanding of the biochemical mechanisms und erlying resistance to RWA. This study was initiated to identify specific po lypeptides induced by RWA feeding that may be associated with RWA resistanc e. The effects of RWA feeding on PI 140207 (a RWA-resistant spring wheat) a nd Pavon (a RWA-susceptible spring wheat) were examined by visualizing, sil ver-stained denatured leaf proteins separated by two-dimensional polyacryla mide gel electrophoresis. Comparisons of protein profiles of noninfested an d RWA-infested Pavon and PI 140207 revealed a 24-kilodalton-protein complex selectively inhibited in Pavon that persisted in PI 140207 during RWA atta ck. No other significant qualitative or quantitative differences were detec ted in RWA-induced alterations of protein profiles. These results suggest t hat RWA feeding selectively inhibit synthesis and accumulation of proteins necessary for normal metabolic functions in susceptible plants.