FUNCTIONS OF POLYAMINES IN THE REGULATION OF ABIOTIC STRESS TOLERANCE IN PLANTS

The growth, development, and productivity of plants are significantly impacted by environmental stress factors. Consequently, plants have evolved a variety of adaptation techniques to maintain their survival in adverse environmental conditions. One such method is the use of metabolites to improve stress tolerance. Polyamines (PAs), a class of metabolites, have distinguished themselves as significant players in this area and they are organic growth agents that take part in a variety of biological processes. They modulate plant metabolism, thereby influencing the growth and development of plants. Several common polyamines, including spermine, spermidine, and putrescine, have been identified as important regulators in controlling and modulating stress tolerance in plants. Accumulation and increasing activity of these polyamines, together with their synthesizing enzymes, have been proven to improve stress tolerance in plants. In this review, a comprehensive summary is provided on the role of polyamines in enhancing stress tolerance against various abiotic stress factors in plants. Also, polyamines have been shown to play a role in stress tolerance by altering the homeostasis of reactive oxygen species (ROS) through their direct or indirect actions in regulating antioxidant systems or decreasing ROS generation.