Characterization of the promoter region of a cytochrome c gene from sunflower

ARCE AGUSTÍN; ARIEL FEDERICO; IVANA VIOLA; RAQUEL CHAN

Pinamar, Buenos Aires

Congreso; XLI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular, SAIB.; 2005

SAIB

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Cytochrome c is a small nuclear encoged hemoprotein that participates in mitochondrial electron transport chain. In a previous work we have reported that at least two genes encoding this protein are present in the sunflower genome. Northern blot analysis and in situ hybridization have indicated that cyt c is primarily expressed in flowers and roots. An 856 pb DNA fragmen corresponding to cyt c promoter region has been isolated by inverse PCR and its sequence deermined. In silico analysis reveals putative binding sites for transcription factors and a Telo box motif. To gain insightinto the segments/boxes responsibles of its expression, we have cloned the entire and serial deletions of this cyt c promoter region fused to the gus reporter gene, and tranformed Arabidopsis thaliana plants with them. Histochemical analysis of transgenic palnts indicate that the whole fragment directs expression in anthers, root tips, nascent lateral roots and vascular tissue from hypocotyls and roots and includes a repressor binding site. Shorter fragments direct expression also in leaves vascuar tissues, cotyledons and sepals while pollinic sacs staining disappeares. The results indicate that tissue specific expression is directed by this promoter. We were able to detect reions responsible for this expression. Conservaion and divergence between species of active cic elements will be presented and discussed.