Fig. 3: Biosynthesis of SA from BA-CoA by the peroxisomal OSD2, endoplasmic reticulum-resident OSD3 and cytoplasmic OSD4 enzymes.
From: Complete biosynthesis of salicylic acid from phenylalanine in plants
a, Expression of OSD2, OSD3 and OSD4 in the root, stem, leaf and panicle of 70-day-old ZH11 plants. b, Expression of OSD2, OSD3 and OSD4 in the leaves of ZH11 plants at 12 h, 24 h, 48 h and 72 h after Xoo inoculation. Gene expression in the Xoo-infected group was normalized to the mock group. Data are mean ± s.d.; n = 3 (a,b) biologically independent samples. Statistical analysis by two-sided Student’s t-tests (b). Exact P values are presented in Supplementary Table 2. c, Subcellular localization of OSD2, OSD3 and OSD4 in rice protoplast. mCherry–HDEL is an endoplasmic reticulum-localized marker. Scale bars, 5 μm. The fraction of protoplasts showing the localization pattern to total co-transformed protoplasts analysed is shown at the top right of each merged image. d, Two hypothetical routes for SA biosynthesis from BA-CoA in rice. e, DAD chromographs of the reaction from BA-CoA and BAlc to BB catalysed by the BA-CoA:benzyl alcohol benzoyltransferase OSD2. f, MS fragmentation (GC Orbitrap MS) pattern of the OSD2 enzymatic product and BB standard. g, DAD chromographs of the reaction from BB to BS catalysed by BB 2-hydroxylase OSD3. h, MS/MS fragmentation (LC–MS/MS, triple TOF) pattern of the OSD3 enzymatic product and BS standard. i, DAD chromographs of the reaction from BS to SA catalysed by the BS carboxylesterase OSD4. j, MS/MS fragmentation (LC–MS/MS) pattern of the OSD4 enzymatic product and SA standard. All experiments were repeated at least twice with similar results.
