Figure 2.

Biosynthesis of N^δ-Acetylornithine from Other Amino Acids.

(A) Possible pathways leading from Arg, Pro, and Glu to N^δ-acetylornithine. 1, Arginase (At2g39020 and At4g08900); 2, Pro dehydrogenase (At3g30775 and At5g38710); 3, Orn δ-aminotransferase (At5g46180); 4, pyrroline-5-carboxylate synthase (At2g39800 and At3g55610); 5, Orn N^δ-acetyltransferase (At2g39030).

(B) Incorporation of [U-¹³C]Arg, [U-¹³C]Pro, and [U-¹³C]Glu into N^δ-acetylornithine in MeJA-treated Arabidopsis leaves, expressed as the percentage of labeled [¹³C₅]N^δ-acetylornithine and unlabeled [¹²C]N^δ-acetylornithine in rosette leaves. Mean ± se of n = 3.

(C) N^δ-acetylornithine accumulation in arginase mutants. Mean ± se of n = 5. Letters indicate significant differences, P < 0.05, analysis of variance, followed by Tukey’s HSD test.