Enhancement of phenolic compounds in olive plants (Olea europaea L.) and their influence on resistance against Phytophthora sp.

The total phenol levels in different olive organs and tissues are studied. The HPLC-MS studies point to the presence of oleuropein, catechin and tyrosol as some of the main phenolic compounds in these extracts. The effect of Brotomax treatment on phenolic compound levels in this plant and the possible role of these compounds as antifungal agents against Phytophthora sp. are also studied. An increase in the total phenol content of leaves and stems was observed 120 days after treatment with 0.3% Brotomax. The cortex was the stem tissue which showed the greatest accumulation of these secondary compounds. An in vitro study of the inhibitory effect of these compounds on fungal growth revealed that tyrosol was the most active agent, followed by catechin and oleuropein, their fungitoxic effect being greater when they acted synergically. (C) 2003 Elsevier Ltd. All rights reserved.