Avenanthramide Biosynthesis in Oat Cultivars Treated with Systemic Acquired Resistance Elicitors

摘要

The synthetic systemic acquired resistance elicitor benzothiadiazole (BTH) has been shown to elicit avenanthramide biosynthesis in the oat cultivar 'Belle'. This report investigates the response of multiple oat cultivars to BTH as well as 2,6-dichloroisonicotinic acid (INA) at different growth stages. Oat seedlings ('Gem', 'Kame' and 'Ogle') were treated with 2,6-dichloroisonicotinic acid (INA) or benzothiadiazole (BTH) at the three leaf (Z13) stage and subsequently assessed for accumulation of avenanthramides and analyzed for the activities of hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroycinnamoyl transferase (HHT). In addition, four cultivars ('Belle', 'Gem', 'Kame', and 'Ogle') were treated at the Z43 stage with BTH. The results indicated that after 48 h avenanthramides accumulated to significantly higher levels in the oat leaves in response to both INA and BTH treatment and this response tended to be fairly long lasting (336 h or more). Both elicitors also raised the activities of HHT enzyme in seedling leaves after 48 h. Genotypic differences in the kinetics and quantitative response were also observed in both the seedlings and the mature plants. The magnitude of avenanthramide production in the leaves was somewhat higher in the more mature plants. Filling grain also showed higher levels of avenanthramides compared to the untreated controls.