, Volume 21, Issue 3, pp 811–819 | Cite as

An active photosynthetic electron transfer chain required for mcyD transcription and microcystin synthesis in Microcystis aeruginosa PCC7806

  • Emma Sevilla
  • Beatriz Martin-Luna
  • M. Teresa Bes
  • Maria F. Fillat
  • M. Luisa Peleato


In this study, quantitative real time RT-PCR has been used to monitor changes in the levels of transcripts encoding mcyD in Microcystis aeruginosa PCC7806 under oxidative agents and different conditions of light intensity. Microcystin content has also been determined in the same stressed cell aliquots. Our results corroborate the fact that changes in light intensities are able to induce mcyD gene transcription, but our data show that this is an early and short-term event. mcyD transcription requires an active photosynthetic electron transfer chain and the increased transcript level as a consequence of light is not related to oxidative stress. Indeed, oxidative stress leads to a general trend of a decrease of mcyD trancript. Microcystin amount found in the cells follows a tendency consistent with the mcyD transcript level. In summary, the data indicate that the synthesis of microcystin is dependent on photosynthesis, and also show that oxidative stress decreases the microcystin synthesis in toxigenic Microcystis.


Microcystin mcy operon mcyD Photosynthesis Oxidative stress 



This work was funded by the Spanish Ministry of Education and Science and FEDER (BFU2006-03454, PET2006-0089 and BFU2009-07424).


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Emma Sevilla
    • 1
  • Beatriz Martin-Luna
    • 1
  • M. Teresa Bes
    • 1
  • Maria F. Fillat
    • 1
  • M. Luisa Peleato
    • 1
  1. 1.Departamento de Bioquimica y Biologia Molecular y Celular, Facultad de Ciencias, and BIFIUniversidad de ZaragozaZaragozaSpain

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