Converts the prephenate and L-arogenate produced from the shikimate-chorismate pathway into 3-phenylpyruvate and phenylalanine (Phe), respectively (PubMed:20215586). Involved in floral volatile benzenoids and phenylpropanoids (FVBP) production (By similarity). H(+) + prephenate = 3-phenylpyruvate + CO2 + H2O H(+) + L-arogenate = CO2 + H2O + L-phenylalanine kcat is 1.231 sec(-1) with L-arogenate as substrate (PubMed:20215586). kcat is 0.060 sec(-1) with prephenate as substrate (PubMed:20215586). Amino-acid biosynthesis; L-phenylalanine biosynthesis; L-phenylalanine from L-arogenate: step 1/1. Expressed at low levels in petals (corollas and tubes), stems, leaves, pistils, stamens, ovaries and sepals. Barely expressed throughout flower development.