Osmolytes: Efficient oxidative stress-busters in plants

Abstract

Owing to their sessile nature, plants are inevitably exposed to a wide range of abiotic and biotic stress factors. The impact of most of these stress factors on plants is reflected in severe consequences for their health and significant decrease in their overall productivity. As overlapping effects at the cellular level, most of these stress factors mainly cause cellular-water imbalance and also oxidative stress, a physiological condition in which there is an imbalance between the generation and scavenging of varied reactive oxygen species (ROS), which eventually causes damages to cellular organelles and vital macromolecules, impairs cellular redox homeostasis, and finally results in cellular metabolic arrest. Notably, to combat the major consequences of oxidative stress and also to maintain cellular redox homeostasis under abiotic stresses, there occur the biosynthesis and accumulation of various osmolytes, which are mostly inert solutes and/or osmoprotectants. Taking into account relevant literature, this chapter aims to: (i) introduce the relation of plant health with varied stress factors; (ii) overview oxidative stress, oxidative markers, and antioxidant metabolism; (iii) briefly enlighten the major modulators of oxidative stress markers and antioxidant metabolism; (iv) discuss the role of major osmolytes in protection of plants against oxidative stress; and also (v) highlight the topics so far unexplored in the present context.