Researchers have discovered the orobanchol synthase responsible for converting the strigolactone (SL) carlactonoic acid, which promotes symbiotic relationships with fungi, into the SL orobanchol, which causes root parasitic weeds to germinate. By knocking out the orobanchol synthase gene using genome editing, they succeeded in artificially regulating SL production. This discovery will lead to greater understanding of the functions of each SL and enable the practical application of SLs in the improvement of plant production.