Figure 5
Arginine increases NO production in Synechococcus PCC 7335. (a) NO production by Synechococcus grown in ASNIII medium (OD 600 = 0.3) with or without the addition of different concentrations of arginine. NO was detected with the fluorescent probe DAF-FM DA using a microwell fluorometer over a 60 min period. Data are expressed as fold increase with respect to the control. Error bars represent ± SE (n = 3). Letters denote significant differences among treatments (ANOVA test, F2,6 = 26.512; post hoc test Holm-Sidak method, p < 0.05). Inset: NO fluorescence expressed as arbitrary units (AU). A representative graph of three independent experiments is shown. (b) NO production in Synechococcus PCC 7335 grown in ASNIII medium treated with 5 mM arginine in the presence or absence of 5 mM of L-NAME. Error bars represent ± SE (n = 4). Letters denote significant differences among treatments (ANOVA test, F3,8 = 230.535; post hoc test Holm-Sidak method, p < 0.001). (c) RT-PCR and western blot (WB) analysis showing the expression of SyNOS in Synechococcus PCC 7335. The RNase P RNA (RNPB) was used as a control for cDNA loading. SyNOS was detected with a specific antibody (Genscript). Full length blots are shown in Supplementary Fig. S5.
