In plant science, small molecules with biological activities are widely used to elucidate and understand biological systems. For example, plant hormones are essential for normal plant growth, and regulating their functions leads to significant changes in plant phenotypes. Strigolactones (SLs) are carotenoid-derived small molecules that have a broad spectrum of functions, including plant hormone activities and chemical mediation of rhizosphere communication with root parasitic weeds and arbuscular mycorrhizal fungi. Therefore, chemicals that regulate the SL functions would be widely used in agriculture. For example, a variety of compounds with SL-like activity have been developed to reduce the seed banks of root parasitic weeds in the field. Other compounds with SL-like activity selectively suppress shoot branching while weakly or not stimulating germination of root parasitic weeds. Inhibitors of SL receptors, conversely, can induce increased shoot branching and dormancy of root parasitic weeds. Small molecules that bind to SL biosynthetic enzymes inhibit SL biosynthesis, thus mimicking mutations in SL biosynthesis and perception, leading to increased shoot branching and seed dormancy of root parasitic weeds. In recent years, some SL function regulators have been designed based on the reaction mechanisms of SL biosynthetic enzymes and SL perception. Here, we overview the SL function regulators reported to date and discuss their potential applications in agriculture.
