INDUCED RESISTANCE IN TOMATO BY OLIGOSACCHARIDES AND GLUTATHIONE

The enhancement of the natural defense of plants against phytopathogens is an interesting perspective allowing pesticide reduction in the environment. Oligosaccharine and glutathione are components of various products with biostimulant activity on plants which are commercialized as fertilizers and are proposed as promoters of plant growth and inducers of defense mechanisms. The aim of this study has been to evaluate the resistance induced in tomato by oligosaccharine and glutathione through the detection of foliar enzymatic activities correlated with biochemical defense of plant. The basal part of plants, eight true foliar stage, has been treated with oligosaccharides (1 mg /hl), glutathione (60.6 mg/hl), singly and in combination, and acibenzolar S-methyl (1.125 g/hl). The total proteins of leaves, removed from the upper part of each plant, were extracted two days after treatment and their peroxidase, chitinase and glucanase activities were determined. Glutathione, oligosaccharides and their mixture caused significant increases of all three enzymatic activities compared to the non treated control, however no synergistic effect of the mixture was observed. Peroxidase and glucosaminidase activities following treatment with glutathione, oligosaccharides or their mixture were lower than those stimulated by acibenzolar S-methyl. Based on these results, the application of products containing glutathione and oligosaccharides could represent a way to enhance tomato plant defense response to pathogen attacks.