Plants facing oxidative challenges-A little help from the antioxidant networks

A large number of reviews have discussed many aspects of oxidative burst due to plant exposure to biotic and abiotic stresses, including the dual role of reactive oxygen species (ROS) as both signaling and toxic compounds, and the strategies developed by plants to cope with this oxidative imbalance. In this review, we have concentrated on fresh new information and other promising and emerging topics of oxidative stress and antioxidant mechanisms in plants, giving particular attention to genotoxicity, transgenerational alterations and quantitative trait loci (QTL) associated with enhancements in the plant tolerance to stresses. Furthermore, besides the discussion of the classical enzymatic and non-enzymatic components of plant defense, novel aspects about the components of the antioxidant machinery, which now includes sugars, annexins and dehydrins, are also presented, along with a final section on future directions in this field.