From activation to desensitization: How ABA balances plant growth and abiotic stress response?
Abscisic acid (ABA) signaling is a central regulator of plant adaptation to abiotic stress, dynamically coordinating stress responses with growth and development. Rapid activation of ABA signaling promotes plant survival during the early stages of stress, whereas prolonged stress requires timely attenuation of the pathway to restore growth and prevent excessive stress responses. Recent studies have uncovered diverse mechanisms underlying ABA desensitization, including regulation of SnRK2 kinases, phytohormone crosstalk, nutrient signaling, protein trafficking, post-translational modifications, and feedback regulatory networks. Together, these interconnected mechanisms enable plants to fine-tune ABA signaling in response to developmental and environmental cues. In this review, we summarize recent advances in understanding the molecular mechanisms that attenuate ABA signaling and restore the balance between growth and stress adaptation during prolonged stress. We also highlight outstanding questions and discuss strategies for engineering ABA signaling dynamics to improve crop resilience, productivity, and adaptation to increasingly variable environments.