PLANT HORMONES.ORG

SL Biosynthesis Pathway: SLs are synthesized from all-trans β-carotene by a D27 isomerase, which converts all-trans beta-carotene to 9-cis-β-carotene.  9-cis-β-carotene is then converted to 9-cis-β-apo-10’-carotenal by CCD7 which is then converted to the SL precursor CL, carlactone, by CCD8. CL can then undergo various synthesis pathways to produce structurally different SLs, such as strigol, orobanchol and SL-like products. Orobanchol-type SLs can be produced from CL by OS900, a CL oxidase, and OS1400, Orobanchol synthase, enzymes. Alternatively, CL can be converted to SL-like products by cytochrome p450 AtMAX1, which oxidizes CL to produce CLA, carlactonic acid. Lastly, CLA can then be converted to a SL-like product MeCLA, methyl carlactonoate, through a currently unknown methyltransferase