Characterization of transgenic plants with different levels of ferredoxin

BLANCO N.E.; POLI, H.O.; VALLE,E.M.; CARRILLO, N.

Pinamar, Buenos Aires, Argentina

Congreso; SAIB-XLI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (S.A.I.B.); 2005

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (S.A.I.B.)

Ferredoxins (Fd) are a group of low molecular-weight proteins which  have Fe-S centres. Plant-type Fds, that have one 2Fe-2S cluster per  molecule, acts 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. Moreover, there are other Fd-depedent enzymes, in  which the reducing equivalents are utilized for nitrogen and sulphur  assimilation and for nitrogen fixation. We have developed transgenic  plants with different levels of ferredoxin. Plants with reduced levels  of this protein were obtained using antisense technology and  silencing using RNAsi. These 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. On the other side, plants with higher than physiological levels of  ferredoxin did not show striking differences when were compared  with wild-type ones. All these results allow us to suggest that a  small reduction in the levels of Fd would lead to drastic alterations  in the growth and development of plants.