FIG 4.

Levels of different protective enzymes against reactive oxygen species (ROS) as determined by enzyme assays using leaf protein extracts (GST, glutathione S-transferase; GPX, guaiacol peroxidase, SOD, superoxide dismutase). Line 1, plants infected on pruning wounds; lines 2 to 5, plants protected in pruning wounds with chitosan oligosaccharide, garlic extract, vanillin, and CGV mix, respectively; lines 6 to 9, plants infected on pruning wounds that have been previously protected by the application of chitosan, garlic extract, vanillin, and CGV mix, respectively; line 10, untreated and noninoculated control plants. Each bar corresponds to the arithmetic mean of the assays (conducted in duplicate) calculated for the 5 plants selected from each line and their corresponding standard deviations (SD). The values shown correspond to the average obtained for four consecutive measurements (years 2010 and 2011 for EV1 and years 2012 and 2013 for EV2). Bars marked with the same letter do not differ at a P value of 0.05.