Target-based selectivity of strigolactone agonists and antagonists in plants and their potential use in agriculture

Strigolactones (SLs) are small carotenoid-derived molecules that possess a wide spectrum of functions, including plant hormonal activities and chemical mediation of rhizosphere communication with both root parasitic plants and symbiotic arbuscular mycorrhizal fungi. Chemicals that regulate the functions of SLs may therefore have the potential to become widely used in agricultural applications. For example, various SL analogs and mimics have been developed to reduce the seed banks of root parasites in the field. Other analogs and mimics act selectively to suppress branching, with weak, or no stimulation, of germination in root parasites. In addition, some antagonists for SL receptors have been developed based on the mechanisms of SL perception. A better understanding of the modes of action of SL perception by various receptors will help to support the design of SL analogs, mimics, and antagonists with high activity and selectivity. Here, we review the compounds reported so far from the viewpoint of their selectivity to their targets, and the possibilities for their use in agriculture.