Involved in the biosynthesis of citrulline (By similarity). Essential gene that modulates defense response to pathogenic bacteria, conferring susceptibility and repressing salicylic acid (SA) accumulation. 2-oxoglutarate + N(2)-acetyl-L-ornithine = L-glutamate + N-acetyl-L-glutamate 5-semialdehyde Amino-acid biosynthesis; L-arginine biosynthesis; N(2)-acetyl-L-ornithine from L-glutamate: step 4/4. Interacts with the P.syringae pv. maculicola effector HopW1-1 (via C-terminus). Belongs to the class-III pyridoxal-phosphate-dependent aminotransferase family.