Plant biochemical mechanisms of oxidative stress under control conditions

Abstract

The presence of O2 in the earth?s atmosphere originated over 2.2 billion years ago as a consequence of the evolution of oxygenic photosynthetic activity by cyanobacteria. After this, several organisms began to evolve a complex redox metabolism to cope with oxidative stress, giving them the capacity not only to tolerate O2 but also to use it for metabolic transformation and biosynthesis (Halliwell, 2006; Slesak et al., 2007). It is remarkable that for aerobic organisms, O2 is both beneficial and damaging. It is beneficial in its role as an essential electron exchanger for respiration and photosynthesis, besides which O2 is widely used for signal transduction. Conversely, O2 can cause dysfunction of cell components by irreversible modifications to DNA, proteins, sugars, and lipids. Hence, there is a balance/imbalance between the two sides, which is critical for cell functionality and survival (Slesak et al., 2007; Cerny et al., 2018; Moldogazieva et al., 2018).