Development of abscisic acid receptor agonists/antagonists and their application prospect in agriculture: An overview

Abscisic acid (ABA), a plant hormone, is crucial for regulating various physiological and developmental processes in plants, including adaptation to biotic and abiotic stresses. Recent advancements have significantly contributed to our understanding of ABA's biosynthetic pathway, transport, signaling pathway, and metabolism. To overcome the limitations of natural ABA, scientists have developed broad-spectrum and highly active agonists of ABA receptors. However, the practical application of these receptor agonists as agrochemicals still faces several challenges. On the other hand, some ABA antagonists have also been developed to differentiate the functional differences among various receptors more accurately. This can help design ABA agonists that can selectively activate specific physiological responses, thereby eliminating the undesired physiological effects induced by ABA. This paper aims to provide a comprehensive overview of the current ABA receptor agonists and antagonists to assist in developing novel ABA functional analogs with improved efficacy and simpler chemical structures that are suitable for agricultural applications.