INVESTIGADORES
KOLMAN Maria De Los Angeles
congresos y reuniones científicas
Título:
Expression of sucrose metabolism genes in filamentous and unicelullar cyanobacteria under stress conditions.
Autor/es:
KOLMAN, MA; NISHI, CN; SALERNO, G
Lugar:
Puerto Madryn, Chubut
Reunión:
Congreso; XLVI Reunion Anual Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2010
Institución organizadora:
Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular
Resumen:
Sucrose (Suc) metabolism has been reported only in oxygenic photosynthetic organism. Suc is synthesized through a two-step pathway involving Sucrose Phosphate Synthase (SPS) and Sucrose Phosphate Phosphatase (SPP), either in unicellular or filamentous cyanobacterium strains. However, up to date, Suc cleavage by Sucrose Synthase (SuS), has only been reported in filamentous heterocyst-forming cyanobacteria. Microcystis aeruginosa is an unicellular non-N2 fixing strain, well known as one of the most common bloom-forming cyanobacteria in fresh water environments. By genome sequence analysis we retrieved an open reading frame homologous to SuS in M.aeruginosa. The sequence was cloned and expressed in Escherichia coli cells. In addition, the enzyme activity was measured in cell free extracts. The aim of this study was to determine the variation in the expression of SuS genes in a filamentous and a unicellular strain. Both cyanobacteria were subjected to differents conditions that involve the availability of light, nitrogen and salt stress. Expression analysis by RT-PCR showed that the response to salt stress was the same for both strains, while there was a difference in the pattern of expression of SuS gene under dark and light conditions .