CELL WALL PROTEIN AND ITS FUNCTION IN WHEAT SCAB RESISTANCE

摘要

The cell wall was the first barrier to resist a challenged pathogen. Ionically-bound, cell wall proteins have proved to be functioned in some plant-pathogen systems. We studied the ionically-bound, cell wall protein in wheat and its peroxidase mechanism and their differences in infected and noninfected plants. When wheat was infected with Fusarium graminearum, the peroxidase activity of the ionically-bound protein in the incompatible system (resistant response) was significantly increased, but no changes in POD activity were observed in the compatible system (susceptible response). Only in resistant cultivar Sumai 3 was one specific protein, A_(280) 30.5 min, detected in the ionically-bound protein. After incubation with H_2O_2, the size of this protein peak was greatly decreased, which suggests that the 30.5 min protein was a cross-linking protein mediated by wheat peroxidase activity and associated with resistance to wheat scab. Another A_(280) 45.5 min protein was suggested to be associated with the compatible system. After susceptible wheat was infected, the protein was significantly increased.