Cool temperature acclimation in toxigenic Microcystis aeruginosa PCC 7806 and its non-toxigenic mutant.

Through comparisons of a microcystin-producing wildtype strain PCC 7806 and a non microcystin-producing mutant, PCC 7806 , our observations highlight defensive (microcystin production) active (production of degradation enzymes and increased electron sinks) strategies for dealing with cold-temperature induced oxidative stress as well as associated physiological changes. This work increases our understanding of microcystin's intracellular function, and the role it may play in bloom ecology. In combination with other studies, this work begins to experimentally establish a mechanistic foundation to better understand cold-to-warm seasonal transitions from toxigenic to non-toxigenic strains frequently observed .