Insight into the Interaction of Strigolactones, Abscisic Acid, and Reactive Oxygen Species Signals

Abstract

Stress disrupts many physiological processes in plants by causing an increase in reactive oxygen species (ROS), which leads to serious damage to DNA, RNA, lipids, and proteins. Meanwhile, the generated ROS play an important role as signaling molecules, inducing a metabolic cascade that allows plants to tolerate stress. Plant development and stress adaptation are known to be monitored by phytohormones by regulating ROS levels to modulate signaling and prevent oxidative stress. Strigolactones (SLs) and abscisic acid (ABA) are carotenoid-derived hormones that play an active role in stress responses. A strong relationship was discovered between ABA and SLs biosynthesis. ABA was revealed to be involved in the regulation of SL production, and max2 mutants (MAX2 is an F-box protein required for SL signaling) were found to be more sensitive to osmotic stress, with an impaired ABA response. The cross talk between SL and ABA signaling during stress is of major importance. SL signaling has been linked to ROS responses during osmotic stress and nutrient deprivation. Similarly, in water-stressed plants, ABA signals promote stomatal closure via ROS generated by respiratory burst oxidases (RBOH). This chapter summarizes the current understanding of how ROS production, detoxification, and signaling interact with SLs and ABA action to regulate plant growth and metabolism under acute stress conditions.