TOBACCO PLANTS WITH REDUCED LEVELS OF FERREDOXIN USING TWO DIFFERENT TECHNIQUES

BLANCO, NICOLÁS, POLI HUGO, CECCOLI ROMINA, VALLE ESTELA NAD CARRILLO NÉSTOR

Rosario, Santa Fe, Argentina

Congreso; XLII Reunion Anual Sociedad Argentina de Investigación en Bioquímica Y Biología Molecular; 2006

SAIB- Sociedad Argentina de Investigación en Biquímica y Biología Molecular

TOBACCO PLANTS WITH REDUCED LEVELS OF FERREDOXIN USING TWO DIFFERENT TECHNIQUES Blanco, Nicolás Ernesto; Poli, Hugo O.; Ceccoli, Romina ; Valle, Estela M.; Carrillo, Néstor Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET), U.N.R., Suipacha 531, Rosario. E-mail: blanco@ibr.gov.ar One approach to study the role of a protein in a biological system is reverse genetic. Antisense technology and RNAsi allow us to reduce the physiological level of a target protein in vivo. Using these tools, we evaluate the role of Ferredoxin (Fd) in the context of the antioxidant defences of the plants. Plant-type Fds, that have one 2Fe-2S cluster per molecule, act as a soluble electronic transporters between Photosystem I and ferredoxin- NADPH reductase (FNR) during the light phase of photosynthesis, to generate NADPH needed for CO2 fixation. Plants with reduced levels of this protein were obtained using both techniques. Antisense plants showed variegated distribution of chlorophyll in the leaf, reduced CO2 fixation rates and lower tolerance to moderate oxidative conditions. Arrested growth, pale green leaves and incapability to generate offspring were observed in seedlings with extreme phenotypes generated by RNAsi silencing. Moreover, only heterotrophic growth was observed in the plants with the lowest levels of Fd. All these results suggest that a small reduction in the levels of Fd would lead to drastic alterations in the growth and development of plants. The functional sustitution of Fd of plant origin by Fd and flavodoxin (Flx) of Anabaena, a filamentous cyanobacteria, was evaluated in double transformants.Antisense technology and RNAsi allow us to reduce the physiological level of a target protein in vivo. Using these tools, we evaluate the role of Ferredoxin (Fd) in the context of the antioxidant defences of the plants. Plant-type Fds, that have one 2Fe-2S cluster per molecule, act as a soluble electronic transporters between Photosystem I and ferredoxin- NADPH reductase (FNR) during the light phase of photosynthesis, to generate NADPH needed for CO2 fixation. Plants with reduced levels of this protein were obtained using both techniques. Antisense plants showed variegated distribution of chlorophyll in the leaf, reduced CO2 fixation rates and lower tolerance to moderate oxidative conditions. Arrested growth, pale green leaves and incapability to generate offspring were observed in seedlings with extreme phenotypes generated by RNAsi silencing. Moreover, only heterotrophic growth was observed in the plants with the lowest levels of Fd. All these results suggest that a small reduction in the levels of Fd would lead to drastic alterations in the growth and development of plants. The functional sustitution of Fd of plant origin by Fd and flavodoxin (Flx) of Anabaena, a filamentous cyanobacteria, was evaluated in double transformants.2 fixation. Plants with reduced levels of this protein were obtained using both techniques. Antisense plants showed variegated distribution of chlorophyll in the leaf, reduced CO2 fixation rates and lower tolerance to moderate oxidative conditions. Arrested growth, pale green leaves and incapability to generate offspring were observed in seedlings with extreme phenotypes generated by RNAsi silencing. Moreover, only heterotrophic growth was observed in the plants with the lowest levels of Fd. All these results suggest that a small reduction in the levels of Fd would lead to drastic alterations in the growth and development of plants. The functional sustitution of Fd of plant origin by Fd and flavodoxin (Flx) of Anabaena, a filamentous cyanobacteria, was evaluated in double transformants.2 fixation rates and lower tolerance to moderate oxidative conditions. Arrested growth, pale green leaves and incapability to generate offspring were observed in seedlings with extreme phenotypes generated by RNAsi silencing. Moreover, only heterotrophic growth was observed in the plants with the lowest levels of Fd. All these results suggest that a small reduction in the levels of Fd would lead to drastic alterations in the growth and development of plants. The functional sustitution of Fd of plant origin by Fd and flavodoxin (Flx) of Anabaena, a filamentous cyanobacteria, was evaluated in double transformants.Anabaena, a filamentous cyanobacteria, was evaluated in double transformants.