Yellow rice to fight vitamin A deficiency
Rice engineered to synthesise beta-carotene (provitamin A) may help prevent vitamin A deficiency, which is a major cause of blindness and death in developing countries. Background Carotenoids are important both to human health and to the food industry. Beta-carotene is a precursor of vitamin A, essential for normal eyesight, growth, bone development and immunity against disease. As antioxidants and free-radical scavengers, carotenoids - used as food colourings and flavours - may help prevent cancer, heart disease and premature ageing. The `Carotene Plus' project, in the European Commission's FAIR programme, set out to genetically engineer crops or micro-organisms to produce selected carotenoids. One achievement to date is the synthesis of beta-carotene in the edible part of rice. The transgenic rice may provide a weapon against vitamin A deficiency, a major health problem in 118 countries. Description, impact and results Carotene Plus has made many carotenoid genes available for study and genetic engineering. In addition to the carotene-containing rice, achievements include vitamin-rich tomatoes and engineered synthesis of a flavour compound. The `rice project' teams introduced daffodil genes for beta-carotene synthesis into rice via a vector carried by the bacterium Agrobacterium tumefaciens. Because leaf carotenoids play an important role in photosynthesis, a vital process best left undisturbed, care was taken to target daffodil gene expression solely at the endosperm or edible part of the rice plant. The transgenic rice grows well and its endosperm is yellow, the colour of beta-carotene. The next step will be to transfer the genes by traditional breeding to rice varieties adapted to local conditions while making absolutely sure that the rice is safe for human health and the environment, in compliance with European legislation. Only then will the seed be made freely available to subsistence farmers in developing countries. The stakes are high: by alleviating vitamin A deficiency in children under school age, it is possible to reduce mortality in this group by up to 23%. Working partnerships The main rice project teams work at the Swiss Federal Institute of Technology and the Albert-Ludwig Universitat Freiburg. Other partners include a seed company, D.J. Van der Have bv in the Netherlands; university teams specialising in plant molecular biology - ENEA, Italy; Royal Holloway and Bedford New College, UK; CNRS, France); carotenoid biosynthesis/regulation and fungal metabolism, Universidad de Sevilla, Spain; and biological chemistry and nutrition at the Universitat Hohenheim, Germany).