Transcriptional regulation of alcohol dehydrogenase during tomato ripening

PONCE-VALADEZ, MÓNICA, DÍAZ DE LEÓN SÁNCHEZ, FERNANDO, PASCUALE, CARLA A., SÁNCHEZ-LECUONA, MAURICIO, LÓPEZ-VIDAL, OMAR, RIVERA-CABRERA, FERNANDO, PEREZ-FLORES, LAURA J.

Guanajuato

Congreso; XIII Congreso Nacional de Bioquímica y Biología Molecular de Plantas y 6to Simposio México-EUA; 2009

Sociedad Mexicana de Bioquímica

The changes in chemical composition that takes place during tomato fruit ripening are responsible of the development of the characteristic color, texture and flavor of ripe tomato. The characteristic tomato flavor is the result of complex interactions between organic acids, soluble sugars and over 400 volatile compounds. These volatiles are derived from different biochemical pathways such as amino acid deamination, lypoxygenation of fatty acids and terpenoid degradation. Alcohol dehydrogenase (ADH) is considered an important enzyme which contributes to flavor development by interconverting aldehyde and alcohol forms of flavor volatiles originated from lipids and aminoacids. The objective of this study was to evaluate ADH activity and expression of ADH during ripening of tomato (Solanum lycopersicum) ?7705?, an important cultivar grown in Hidalgo. Four tomato fruit ripening stages were compared (mature green, turning, light red and red), ADH enzyme activity increased from the mature green stage to the breaking stage, after which it was maintained constant. We observed the same behavior in the ADH gene expression determined by semi-quantitative RT-PCR. These results point to a transcriptional regulation of ADH. Ongoing work in our lab is looking into correlate these results with the synthesis of aroma volatiles during ripening and the effect of refrigeration on tomato flavor development. This research was partially funded by UAM, CONACYT Apoyo Compl.Consl. (No. 35126) and CA PROMEP (No. 34775). We also thank CONACYT for its finantial support to Mónica Ponce Valadez for her postdoctoral stay.