The Effect of Salicylic Acid on Peroxidase Activity in Wheat Calli Cocultured with the Bunt Pathogen Tilletia caries.

The effect of salicylic acid (SA) on peroxidase activity in wheat (Triticum aestivum L.) calli cocultured with the bunt pathogen Tilletia caries was studied. Fungal infection was shown to activate cytoplasmic peroxidase. SA suppressed total peroxidase activity but did not inhibit the peroxidase with pI ∼9.8. A novel chitin-specific peroxidase with pI ∼3.5 appeared after the SA treatment. The infection of S A-treated cells with Tilletia caries activated the isoenzymes with pI ∼3.5, ∼4.8, and ∼7.5 and stimulated their secretion into the culture medium. The ability of SA to control wheat peroxidase activity during pathogenesis is discussed. The important role of this control in plant defense responses to the bunt pathogen is emphasized. [ABSTRACT FROM AUTHOR]