Reactive oxygen species and apoplastic switch

One main common problem during most diseases both of plants and animals is "oxygen stress". The biochemistry of oxygen - activation and - detoxification analyzed in the past has led to the identification of many similar or more or less identical features both in plants and animals. Plants developed a special strategy for defence combining avoidance and tolerance reactions with a sophisticated set of chemicals synthesized either constitutively or when needed. Coevolution of animals took advantage of the synthesizing capacity of plants sparing the synthesis of certain "expensive" groups of chemicals such as phenolics. These phenolics are involved in defence against pathogens and as "preformed" molecules potentially also in the decision between growth or defence by governing the peroxidase-oxidase activities in the apoplast working as "apoplastic switch".