BR biosynthetic pathways, including the late C-6, early C-22, and C-23 oxidation routes. The subpathway indicated by dotted lines has not been verified in planta. BL, brassinolide; CN, campestanol; CR, campesterol; CS, castasterone; CT, cathasterone; TE, teasterone; TY, typhasterol; 22-OHCR, (22S)-22-hydroxycampesterol; 22-OH-3-one, (22S)-22-hydroxy-5α-campestan-3-one; 22-OH-4-en-3-one, (22S)-22-hydroxycampest-4-en-3-one; 22,23-diOHCR, (22R,23R)-22,23-dihydroxycampesterol; 22,23-diOH-4-en-3-one, (22R,23R)-22,23-dihydroxycampest-4-en-3-one; 3-epi-6-deoxoCT, 3-epi-6-deoxocathasterone; 3-one, 5α-campestan-3-one; 4-en-3-one, campest-4-en-3-one; 6-deoxoCS, 6-deoxocastasterone; 6-deoxoCT, 6-deoxocathasterone; 6-deoxoTE, 6-deoxoteasterone; 6-deoxoTY, 6-deoxotyphasterol; 6-deoxo3DT, 3-dehydro-6-deoxoteasterone.