The Path from β-Carotene to Carlactone, a Strigolactone-Like Plant Hormone

Germination of parasitic witchweeds depends on strigolactones, which also regulate plant branching and signal in the context of mycorrhizal symbioses. The biosynthetic pathways that lead to strigolactones are founded in carotenoid biosynthesis, but further steps have been obscure. Alder et al. (p. [1348][1]) have now identified a biochemical pathway that generates a strigolactone-like compound, carlactone, which shows biological actions similar to those of strigolactone. [1]: /lookup/doi/10.1126/science.1218094