Polyamines: New Plant Growth Regulators Promoting Salt Stress Tolerance in Plants

Abstract

Soil salinization is a major abiotic stress that significantly impairs plant growth and development. This leads to various physiological disorders in plants, ultimately posing a threat to global food security. Polyamines are emerging as new plant growth regulators that can help promote salt stress tolerance in plants. Research has shown that application of polyamines, which are organic compounds containing multiple amine groups, can help alleviate the detrimental effects of salt stress on plants. Increasing the levels of polyamines, either naturally during salt stress or through exogenous application, helps establish homeostasis of polyamines within the plant. This polyamine homeostasis then leads to the homeostasis of reactive oxygen species (ROS) through several physiological processes such as hormonal regulation, ion channel regulation, activation of ROS scavenging enzymes, and antioxidant activity. Collectively, these polyamine-mediated physiological changes help the plant establish ROS homeostasis, which is a key mechanism underlying enhanced salt stress tolerance. The balanced regulation of polyamines and ROS is crucial for plant adaptive responses and survival under saline conditions. Overall, the use of polyamines represents a promising approach for developing more salt-tolerant crops and improving agricultural productivity in saline-affected regions.