In cyanobacteria, few details are known of the mechanisms through which the expression of the light-harvesting pigment c-phycocyanin is regulated. In the present study, a 419 bp upstream sequence of the phycocyanin β subunit (
cpcB) gene from
Arthrospira platensis
FACHB341 was fused with green fluorescent protein (
gfp) gene, and a heterologous reporting system was built up to investigate the influence of light intensity on the expression of
gfp gene, and the regulation function of different region of the upstream sequence of
cpcB gene. Results showed that the upstream sequence of
cpcB gene could drive the expression of
gfp gene in
Synechococcus
sp. strain PCC7942, and the expression was influenced by light intensity, the lower the light intensity, the higher the
gfp level. Deletion analysis revealed that a light-responsive element was located in the region -276 to-218, a promoter sequence was in the region -85 to -1, and two positive cis elements were in the -419 to -276 and the -218 to -130 regions, respectively.
