title: An active photosynthetic electron transfer chain required for mcyD transcription and microcystin synthesis in Microcystis aeruginosa PCC7806.
abstract: 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.
authors.affiliation: Departamento de Bioquimica y Biologia Molecular y Celular, Facultad de Ciencias, and BIFI, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: Emma
authors.initials: E
authors.lastname: Sevilla
authors.forename: Beatriz
authors.initials: B
authors.lastname: Martin-Luna
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Bes
authors.forename: Maria F
authors.initials: MF
authors.lastname: Fillat
authors.forename: M Luisa
authors.initials: ML
authors.lastname: Peleato
mesh_terms: D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity; D004579:Electron Transport; D045222:Electron Transport Chain Complex Proteins; D008027:Light; D052998:Microcystins / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity; D046931:Microcystis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D010788:Photosynthesis / Q000502:physiology* / Q000528:radiation effects; D060888:Real-Time Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D001427:Bacterial Toxins; D045222:Electron Transport Chain Complex Proteins; D052998:Microcystins; C078588:microcystin