In the experiment of soaking etiolated wheat seedlings or seedling cultings with helminthosporal phytotoxin produced by root rot pathogen Bipolaris sorokiniana,PAL spe-cific activity of susceptible cvs.was significantly higher than those of the controls and there existed a positive correlation between the enzymatic activity and the toxin concentration while the PAL specific activity change of the resistant cvs. was not significantly observed。The PAL specific activity in the discs of the flag leaves of the resistant cvs.was remarkably lower tha...
