Farré Martinez, Gemma. (2012) . Towards vitamin biofortification in staple cereal crops in a socio-political and food security context. Universitat de Lleida. L-970-2012 ; http://hdl.handle.net/10803/84102.

Transgenic approaches hold great promise in alleviating, to a major extend such micronutrient deficiencies as exemplified by numerous reports in the literature over the past decade. However, there is a limited understanding of the regulatory mechanisms that control the accumulation of specific vitamins in plants. For this reason, I analyzed a maize population expressing combinations of the carotenogenic genes Zmpsy1, PacrtI, Gllycb, Glbch and ParacrtW in an effort to unravel as yet unknown regulatory bottlenecks.I also investigated in more detail the corn bch family. My results suggest that diverse regulatory strategies may be in operation to control the accumulation of carotenoids in endosperm tissue. I recovered multiple independent transgenic rice lines expressing Arabidopsis thaliana ρ hydroxyphenylpyruvate dioxygenase (HPPD), which catalyzes the first committed step in vitamin E biosynthesis. My results revealed bottlenecks that act as metabolic tipping points in the pathway.