1. On page 2: Saturation curves for determination of PsAMADH1 and 2 activities with variable concentrations of NAD + in the presence of 1 mmol l -1 aldehyde substrates. The measurements were performed on Agilent 8453 UV-visible spectrophotometer (Agilent Technologies, Santa Clara, CA, USA) at 30 °C. The reaction mixture was buffered by 0.1 mol l -1 Tris-HCl, pH 9.0. The production of NADH in the enzymatic reaction was monitored at 340 nm (ε = 6,620 l mol -1 cm -1 ). On page 3: The K m values of PsAMADH1 and 2 for NAD + calculated from the graphs are provided in a table. Frömmel J. et al.: N-acyl-ω-aminoaldehydes are efficient substrates of plant aminoaldehyde dehydrogenases Supplementary file 3

2. AB CD

3. Aldehyde (used at fixed concentration of 1 mM) K m of PsAMADH1 for NAD + (μmol l -1 ) K m of PsAMADH2 for NAD + (μmol l -1 ) ABAL 49.0 ± 4.53 58.9 ± 3,78 Valer-APAL 20.8 ± 2.12 46.1 ± 5.68 2-Met-Butyr-APAL19.5 ± 1.4467.6 ± 3.76 3-Met-Butyr-APAL19.9 ± 2.1253.0 ± 4.05 2,2-diMet-Propi-APAL 21.7 ± 1.17 54.3 ± 4,97 Propi-ABAL 25.9 ± 1.72 40.7 ± 2,36 2-Met-Butyr-ABAL13.5 ± 1.1051.4 ± 4.92 3-Met-Butyr-ABAL18.7 ± 1.1448.7 ± 3.58 2,2-diMetPropi-ABAL 22.7 ± 1.75 53.5 ± 6,16