Role of Polyphenols as Antioxidants in Native Species from Argentina Under Drought and Salinization

Abstract

Plants inhabiting arid environments are exposed to drought and, in several cases, also to salt stress as usually occurs in different regions in Argentina. These plants have developed different strategies to avoid or tolerate the lack of water and/or the excess of toxic ions during their development. As drought and salt stress lead to increased production of reactive oxygen species (ROS) in plant cells, halophytic and xerophytic species have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and nonenzymatic components. Production of phenolic compounds is one of the strategies used by some native species of these adverse environments, principally to protect their cells from the oxidative damage caused by drought and salinity. This chapter provides an overview of the oxidative response and the polyphenols involvement as part of a tolerance mechanism in five native species from Argentina: the shrubs Prosopis strombulifera, Larrea divaricata, and Lycium chilense and the grasses Pappostipa speciosa and Poa ligularis which have shown to have a high polyphenol production correlated with a high antioxidant capacity. Also, two of these native species may be considered as important sources of antioxidants and biomolecules for biotechnological purposes.