text: …glnN expression under nitrogen-starvation conditions (Figs 3 and 4); both genes are involved in acclimation to nitrogen limitation in S. elongatus and both are transcriptionally activated by NtcA (Aldehni et al.,
  32 Microbiology 155
  2003; Aldehni & Forchhammer, 2006; Schwarz & Forchhammer, 2005).