Figure 1. (A, B) Inhibitory effects of proteinogenic amino acids on primary root growth. Seedling growth on the vertical plates containing diluted Hoagland media with amino acids (or ammonium nitrate in the control) at 50 µM as the only nitrogen source (n = 9). (C) Transcriptional regulation of selected genes involved in the biosynthesis of Lys, degradation of Lys, and transport of amino acids upon P. syringae inoculation after 2, 6, 24 h, and only after Flg22 elicitor inoculation (1 and 4 h). AK-HSDH: Aspartate Kinase/Homoserine Dehydrogenase1, AK3: Aspartate Kinase3, DHDPR: Dihydrodipicolinate Reductase, DAPDC: Diaminopimelate Decarboxylase, AGD2: Aberrant Growth And Death2 (Diaminopimelate Aminotransferase), ALD1: AGD2-like Defense Response Protein 1; LKR/SDH: Lysine-Ketoglutarate Reductase/Saccharopine Dehydrogenase, CAT1: Cationic Amino Acid Transporter1, LHT1: Lysine Histidine Transporter1, LHT7: Lysine Histidine Transporter7. The color code for upregulation (red), downregulation (blue), and no change (yellow) is given as log values and is shown in the legend at the bottom.