Involved in brassinosteroid biosynthesis (PubMed:15705958, PubMed:16369540). May catalyze a C6-oxidation step and may be involved to supply 6-deoxotyphasterol and typhasterol (PubMed:15705958). Involved in internode elongation and seed development (PubMed:15705958). Catalyzes the conversion of campesterol (CR) to (22S)-22-hydroxycampesterol (22-OHCR, 22-hydroxyCR) (PubMed:16369540). campesterol + O2 + reduced [NADPH--hemoprotein reductase] = (22S)-22-hydroxycampesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Plant hormone biosynthesis; brassinosteroid biosynthesis. Ubiquitously expressed at low levels, but preferentially in the internodes and the florets before flowering. Down-regulated by brassinolide in wild-type and the dwarf11 mutant. The dwarf11 (d11) mutant shows the erection of leaves in mature stages, the shortening of the grain length and of the second internode in culm, and aberrant skotomorphogenesis. Treatment with exogenous brassinolide rescues the abnormal phenotype. Belongs to the cytochrome P450 family.