Analysis of capsinoids in Galician pepper cultivars and characterization of their properties for plant protection

Zusammenfassung

The content in capsaicinoids and capsinoids was analysed in several Galician pepper cultivars. No capsinoids were detected, but capsaicin and dihydrocapsaicin were measured in cultivars Padrón and Mougán. The antimicrobial activity of a capsinoid (vanillyl nonanoate) and its precursors were tested; the capsinoid inhibited Phytophthora capsici spore germination. On the other hand, vanillyl nonanoate protects pepper plants against Botrytis cinerea and Phytophthora capsici through induced resistance. Vanillyl nonanoate induces resistance systemically in both pepper and Arabidopsis plants. The observed induced resistance involves cell wall reinforcement with an increase in lignin as well as other defences as PR proteins in both plant species. Signalling of the vanillyl nanoate systemic response is mediated by hydrogen peroxide, salicylic acid, ethylene and jasmonates in the case of pepper, and salicylic acid and jasmonates in the case of Arabidopsis. Changes in the levels of 4-hydroxybenzoic acid were also detected in pepper and a role for this compound in resistance is discussed.