Functions as flavone synthase II (FNSII) that catalyzes the direct conversion of flavanones to flavones (PubMed:24843076). In vitro, can convert naringenin and eriodictyol to apigenin and luteolin, respectively (PubMed:24843076). Acts as a key branch point enzyme that channels flavanones to the biosynthesis of soluble tricin O-linked conjugates (PubMed:24843076, PubMed:28385728). a flavanone + O2 + reduced [NADPH--hemoprotein reductase] = a flavone + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] Secondary metabolite biosynthesis; flavonoid biosynthesis. Slight reduction in plant height (PubMed:28385728). In cell wall, altered content and composition of lignins derived from typical monolignols (PubMed:28385728). Belongs to the cytochrome P450 family. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.