Regulatory mechanisms of strigolactone perception in rice 

Strigolactones (SLs), a group of carotenoid-derived small signaling molecules and a class of phytohormones, play key roles in regulating various growth and developmental processes in plants. Additionally, they act as rhizosphere signaling molecules that promote symbiosis with arbuscular mycorrhizal (AM) fungi. Despite the identification of key components involved in SL perception and signaling through genetic and biochemical assays, the molecular mechanisms underlying SL signaling remain only partially understood. In a recent study, Hu and colleagues investigated DWARF14 (D14), a crucial SL receptor, and its associated receptor complex components. Their findings reveal that the formation of the D14-D3-ASK1 complex is essential for activating SL perception. SL induces the ubiquitination and degradation of D14, a process that requires direct interaction with D3. This regulatory mechanism is particularly significant in rice under low nitrogen conditions, where it affects tillering. This study provides new insights into the multi-layered regulation of SL signaling and opens opportunities for crop improvement and breeding programs. (Summary by Ching Chan @ntnuchanlab) Cell 10.1016/j.cell.2024.10.009