INBIOTEC   24408
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y BIOTECNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Effect of high light on C and N metabolism in two M. aeruginosa strains
Autor/es:
CAINZOS, M; MARTIN, MV; SALERNO, G; KOLMAN, MA
Lugar:
Florianópolis
Reunión:
Congreso; The 17th International Conference on Harmful Algae; 2016
Institución organizadora:
International Society for the Study of Harmful Algae (ISSHA)
Resumen:
Cyanobacteria are oxygenic photosynthetic organisms found in a diverse range of habitats. Microcystis strains produceblooms (massive proliferations) and are also able to synthesize microcystins, powerful hepatotoxins. M. aeruginosa areresponsible for over 60% of bloom poisoning cases in the world. Recently, it has been reported that microcystin synthesisgenes are up-regulated by stress conditions such as high light. Furthermore, it was shown that microcystins bind to someproteins to stabilize them during oxidative stress, a common condition in a bloom. A comparison between toxigenic andnon-toxigenic Microcystis strains showed that proteins involved in C and N metabolisms and in redox balance exhibitdifferential expression. In this work, we analyzed by RT-PCR the expression of genes involved in C fixation, C/N relationshipregulation, and microcystin synthesis, in a model and in a native M. aeruginosa strain, under different illuminationconditions. We also quantified total microcystin content, and glycogen and cyanophycin (C and N storage compounds,respectively). Our results show a differential expression of genes related to C metabolism and microcystin synthesis in thetwo toxigenic strains under high light. However, no change was detected in the expression of genes involved in N metabolismin similar stress conditions. Besides, while glycogen and cyanophycin contents differ between the two strains, the totalmicrocystin content is not affected by the treatment. We conclude that toxigenic Microcystis strains have differentresponses to stresses, which may be ascribed to different strategies to deal with them. Supported by CONICET, UNMdP andFIBA