High impact information on BP 214

• Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis [1].
• The UGT73C5 of Arabidopsis thaliana catalyses 23-O-glucosylation of the BRs brassinolide (BL) and castasterone [2].
• We also show that Arabidopsis CYP85A2, which was initially characterized as castasterone synthase, also has brassinolide synthase activity [3].
• Overexpression of SOB7 results in a dramatic reduction in endogenous CS levels, and although single null-mutants of BAS1 and SOB7 have the same level of CS as the wild type, the double null-mutant has twice the amount [4].
• ROT3 appears to be required for the conversion of typhasterol to castasterone, an activation step in the BR pathway [5].

Biological context of BP 214

• We expressed CYP72B1 in yeast, coupled with brassinosteroid feeding, and established the biochemical function to be the hydroxylation of BL and castasterone, to give 26-hydroxybrassinolide and 26-hydroxycastasterone, respectively [6].
• Application of brassinolide and castasterone rescued the dpy phenotype, as did C-23-hydroxylated, 6-deoxo intermediates of brassinolide biosynthesis [7].

Anatomical context of BP 214

• Among them, 6-deoxotyphasterol (6-deoxoTY) accumulated to unusually high levels within cells cultured in tracheary element-inductive medium, while castasterone (CS) was not elevated either within or outside cells [8].

Associations of BP 214 with other chemical compounds

• These brassinosteroids, and the previously identified campesterol, campestanol, 6-deoxocastasterone and castasterone, in the roots are members of a biosynthetic pathway to castasterone, namely the late C-6 oxidation pathway, suggesting that its biosynthetic pathway is operative in the roots [9].

Gene context of BP 214

• In these plants, the late C-6 oxidation pathway was found to be the predominant pathway in the synthesis of castasterone [10].

References