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
