Regulation of brassinosteroid biosynthesis

Fujioka et al. [37] found through rescue experiments of the det2 mutant using brassinolide precursors that 6-deoxo intermediates of brassinolide show stronger activity than 6-oxo 

Transcription of the CPD gene which is involved in the conversion of cathasterone to teasterone has been found to be specifically down-regulated by BRs in both dark and light 

Metabolism of castasterone, brassinolide, 24-epibrassinolide, 22,23,24-triepibrassinolide in plants or explants 

In the rice lamina inclination bioassay using etiolated rice lamina, castasterone is highly active. Castasterone is actively incorporated into the tissues. However, no conversion of castasterone to brassinolide was detected [54,55]. Instead castasterone was rapidly metabolized into very polar, non-glycosidic metabolites which were more polar than BR glucosides as examined by the reversed-phase HPLC (Table 3). However, the structures of these polar metabolites remained undetermined. 

Metabolites of castasterone and brassinolide in seedlings and explants of plants 

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