Variation in the synthesis of microcystin in response to saline and osmotic stress in Microcystis aeruginosa PCC 7806

The growth and synthesis of microcystin in Microcystis aeruginosa PCC7806 was studied in cells grown in the presence of NaCl or with sucrose. The saline stress caused a decrease in the transcript levels of mcyD, one of the genes involved in microcystin synthesis, which was correlated with a decrease in the content of microcystin-LR in the cells. The cells treated with sucrose also had reduced levels of mcyD transcripts and contents of microcystin-LR.