Fig. 3.

Heatmap indicating the expression of the genes encoding the five investigated small proteins in Synechocystis strains PCC 6803 and PCC 6714 under 10 different growth conditions: exponential (Exp.) and stationary growth phase (Stat.); cold (15 °C) and heat (42 °C) stress for 30 min each; depletion of inorganic carbon (−C), cells were washed 3 times with carbon-free BG11 and cultivated further for 20 h; dark, no light for 12 h; Fe²⁺ limitation (−Fe), addition of iron-specific chelator desferrioxamine B (DFB) and further cultivation for 24 h; high light (HL), 470 μmol photons m⁻²s⁻¹ for 30 min; nitrogen depletion (−N), cells were washed 3 times with nitrogen-free BG11 and cultivated further for 12 h; phosphate depletion (−P), cells were washed 3 times with phosphate-free BG11 and further incubated for 12 h. Data derived from previous genome-wide expression analysis by differential RNA-Seq [20, 21]. Values indicate sequencing read counts for the primary 5′ end (= transcriptional start site [TSS]) of the corresponding transcriptional unit (TU). The TSS positions are given for the Synechocystis genomes available under accession numbers BA000022 and CP007542. The colour varies from red (no expression) to yellow (intermediate expression) to green (high expression)