Figure 5

Metabolism of Arg and Orn is impaired in oat mutants. Col-0 wildtype, oat1 and oat3 were cultivated for 3 weeks on MS medium lacking mineral nitrogen but supplemented with 30 mM sucrose, 0.5 mM Gln and an additional organic nitrogen source corresponding to 20 mM nitrogen. A: Addition of 0.5 mM Gln to 5 mM Arg allowed establishment and limited growth of oat mutant seedlings. B-D: Profiles of the major free amino acids in excised rosettes of plantlets cultivated on the indicated nitrogen sources. Values are the average of 3 to 4 independent biological replicates, error bars indicate SD. Asterisks indicate significant differences from the wildtype Col-0 (p ≤ 0.05). For the full amino acid profiles see Fig. 6.