CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Análisis de transcriptos codificantes de enzimas remodeladoras de la pared celular en tomates Micro-Tom almacenados a distintas temperaturas durante la poscosecha
Autor/es:
MULLER, G.; TRIASSI, A; BUDDE, C; MARIA FABIANA DRINCOVICH; ANDREO, CARLOS S; LARA, MV
Lugar:
Buenos Aires
Reunión:
Congreso; VIII Simposio Nacional de Biotecnología REDBIO.; 2011
Resumen:
Vine life of the red ripe (RR) tomato is hardly a few days; consequently to extend fruit market life, tomatoes are harvested at stages prior to RR and kept at temperatures below optimum to delay ripening. Since tomatoes are sensitive to low temperature (4ºC), commercially storage uses 12-15 °C. In the present research the response of fifteen transcripts encoding proteins involved in cell wall modeling was analyzed during the postharvest at different temperatures. The expression profile in tomato fruit cv. Micro-Tom ripening on the vine was compared to that of harvested fruit at mature green stage kept for 7 d at 4; 15 or 20ºC. Thereafter fruits were kept at 20ºC for another 2 days. Storage at 4ºC delayed ripening but also enhanced oxidative metabolism, induced membrane damage and had a profound impact on the expression on the enzymes analyzed. After transferring to 20ºC for 2 days firmness was not decreased and transcript profile remained altered. On the other hand, storage at 15ºC delayed ripening with the benefit of not enhancing the oxidative metabolism and of enabling the achievement of a ripe type phenotype upon transferring to ambient conditions. Nevertheless, increased levels of transcripts encoding poligalacturonase and of two b-xylosidases (Xyl1-2) accompanied with a remarkable decrease in Expansin1 were observed. Changes in the expression profiles of Xyl1 and -2, and of seven xyloglucan endotransgylcosylase/hydrolases (XTHs), suggest them as putative determinants of either fruit softening or quality. Finally, besides below ambient storage conducts to the reduction in the ethylene production, the response to cold on cell wall metabolism is mediated by other signals, as accounted in variations in TBG4,Cel1, XTHs and Xyl1-2