Water Stress and Redox Regulation with Emphasis on Future Biotechnological Prospects

Abstract

Water deficit conditions can disturb the redox homeostasis in plants and result in increased production of reactive oxygen species (ROS), which could ultimately lead to plant death. Many regulatory mechanisms exist in plants to overcome the damaging effects of free radical accumulation. These include morphological changes and the production of enzymatic and non-enzymatic anti-oxidants. Anti-oxidants accumulate in an organized manner in different cellular compartments of which the chloroplast especially is vital in maintaining redox homeostasis during water deficit conditions. The signaling mechanisms in plants during water deficit are complex. This ranges from hormonal signaling to where sugars, such as sucrose, RFOs, trehalose and fructans, are suggested to contribute significantly to the redox homeostasis mechanisms through ROS scavenging. These sugars display characteristics of osmoprotectants and anti-oxidants. Worth investigating is the modulation of sugars and key metabolic enzymes during the development of drought-tolerant crops. The use of direct genome-editing techniques such as CRISPR/Cas9 could be very useful in developing new tolerant crop varieties. Also, a multitude of health beneficial phenolic and sugar compounds accumulate in plant vacuolar compartments as a part of the redox homeostasis mechanism. Future studies could seek to implement environmental stresses in a positive light to enhance food quality and establish the concept of producing functional foods.