Transcriptional regulation of genes encoding vitamin E biosynthetic enzymes determines tocopherol accumulation in tomato

LEANDRO QUADRANA, JULIANA ALMEIDA SANTIAGO N. OTAIZA, TOMAS DUFFY, JUNIA V. CORRÊA DA SILVA, FABIANA DE GODOY, RAMON ASIS, LUISA BERMÚDEZ, ALISDAIR R. FERNIE, MAGDALENA ROSSI AND FERNANDO CARRARI

Encuentro; Gordon Research Conference; 2012

Tocopherols are a group of amphiphilic antioxidants belonging to the vitamin E (VTE) family and its biosynthesis requires the condensation of two precursors, phytyl 2P, and homogentisate, coming derived from two different precursor pathways, methylerythritol phosphate and shikimate. Although tomato fruits are important sources of VTE, its biosynthesis has been scarcely studied. In order to provide insights into the regulation of tocopherol biosynthesis in tomato, we analyzed the expression of 47 enzymes encoding genes expression of 47 enzymes involved in the biosynthetic pathway of VTE by a dedicated qRT-PCR array on different tomato tissues. Combining a high accurate qPCR array, metabolite data and bioinformatics analyses of promoter regions, key steps and bottlenecks in vitamin E biosynthesis regulation were uncovered. As a proof of concept, we analyzed the expression level of several VTE related genes and tocopherol profile of on seventeen Andean tomato species from the Lycopersicon section, with different geographic origins and evolutionary history. The integrated analyses allowed us to propose targets for metabolic engineering aiming to improve the content of this important nutraceutical compound in tomato.