Figure 2: Functional specialization of CYP98A8 and CYP98A9 in vivo.
From: Evolutionary interplay between sister cytochrome P450 genes shapes plasticity in plant metabolism
(a) The anther-specific phenolamide pathway as previously delineated in A. thaliana. (b–e) Targeted metabolic profiling in A. thaliana flower buds shows that phenolamide intermediates downstream of N1,N5,N10-tri-coumaroyl-spermidine are absent from the cyp98a9 mutant, indicating that CYP98A8 does not perform the 3′-hydroxylation in vivo: (b) N1,N5,N10-tri-coumaroyl-spermidine, (c) N1,N5,N10-tri-feruloyl-spermidine, (d) N1,N5,N10-tri-(hydroxyferuloyl)-spermidine, (e) N1,N5-di-(hydroxyferuloyl)-N10-sinapoyl-spermidine. Results are the mean±s.e. of three independent determinations. Reversible activity of the spermidine:hydroxycinnamoyl transferase acting upstream of CYP98A9 presumably accounts for the lower accumulation of the N1,N5,N10-tri-coumaroyl-spermidine in the cyp98a9 mutant compared with the accumulation of N1,N5,N10-tri-feruloyl-spermidine in cyp98a8.
