PROTEIN-COMPOSITION OF WHEAT APOPLASTIC FLUID AND RESISTANCE TO THE RUSSIAN WHEAT APHID

The protein composition of intercellular fluids from three different w heat cultivars (Triticum aestivum L. cvv. Tugela DN, Molopo DN and Bet ta DN) with resistance to the Russian wheat aphid, Diuraphis noxia (Mo rdvilko) and the corresponding near-isogenic susceptible cultivars (Tu gela, Molopo and Betta) were studied under conditions of infestation a nd non-infestation. The aim was to gain information on the mechanism o f resistance and the possible presence of molecular markers of resista nce. Aphid infestation induced the accumulation of specific correspond ing proteins in the intercellular fluids of resistant cultivars only. The infestation-related proteins were of different molecular mass rang es (28-33; 22-24; 18.5-19.5 and 15.5-17 kDa). Some were serologically related to PR proteins. We suspect that the infestation-related protei ns are involved in resistance to the Russian wheat aphid. Although not particularly time saving, the intensified bands of infestation-relate d proteins on SDS-PAGE gels may be useful for determining resistance.