Figure 1.

Proposed Biosynthetic Pathways Leading to the Formation of Benzoyl-CoA and Benzenoid/Phenylpropanoid Volatile Compounds in Petunia Flowers.

Solid arrows indicate established biochemical reactions, and broken arrows depict possible steps not yet described. Stacked arrows show the involvement of multiple enzymatic steps. Gray arrow shows a potential step. Volatile benzenoid/phenylpropanoid compounds are highlighted with a blue background. The CoA-dependent β-oxidative pathway leading to benzoyl-CoA formation is localized in peroxisomes and shown with a pink background. BA-CoA, benzoyl-CoA; BAlc, benzylalcohol; BAld, benzaldehyde; BALDH, benzaldehyde dehydrogenase; BB, benzylbenzoate; BPBT, benzoyl-CoA:benzylalcohol/2-phenylethanol benzoyltransferase; BSMT, BA/salicylic acid carboxyl methyltransferase; CA, cinnamic acid; CA-CoA, cinnamoyl-CoA; CFA, caffeic acid; CFA-CoA, caffeoyl-CoA; C3H, p-coumarate-3-hydroxylase; C4H, cinnamate-4-hydroxylase; CCoAOMT, caffeoyl-CoA 3-O-methyltransferase; 4CL1, 4-coumaroyl-CoA ligase; Eug, eugenol; FA, ferulic acid; FA-CoA, feruloyl-CoA; IEug, isoeugenol; 3H3PP, 3-hydroxy-3-phenylpropionic acid; 3H3PP-CoA, 3-hydroxy-3-phenylpropionyl-CoA; KAT, 3-ketoacyl-CoA thiolase; MB, methylbenzoate; 3O3PP-CoA, 3-oxo-3-phenylpropionyl-CoA; OMT, O-methyltransferase; PAAS, phenylacetaldehyde synthase; pCA, p-coumaric acid; pCA-CoA, p-coumaroyl-CoA; PEB, phenylethylbenzoate; PhA, phenylacetaldehyde; PhEth, 2-phenylethanol.