Activation of stress resistance in plants and consequences for product quality

Unfavourable environments (stressors) enhance the formation of radicals and increase the oxidative potential in plant tissues. Superoxide dismutase, c atalase and other radical-eliminating reactions counteract this oxidative s tress. Additionally, plants produce stress-diminishing metabolites and deve lop resistance mechanisms at the biochemical, physiological and morphologic al level. In this contribution the activation of resistance responses is de monstrated with the following examples: formation of resveratrol as a phytoalexin and antioxidative compound in var ious genotypes of potato formation of(antioxidative) phenylpropanoids in plants, stimulated by mycor rhiza and rhizobacteria stress-diminishing effects at the molecular, biochemical, physiological and yield-related level in crops, caused by treatments with alkanolamines. Consequently, a resistance activation results in changes of plant biochemis try and food quality.