Provitamin A Biofortification of Durum Wheat through a TILLING Approach

Macro and micronutrients, essential for the maintenance of human metabolism, are daily assimilated through the diet. Wheat and other major cereals are a good source of nutrients, such as carbohydrates and proteins, but cannot supply enough amounts of essential micronutrients which includes provitamin A. As vitamin A deficiency (VAD) lead to several serious diseases spread worldwide, the biofortification of a major staple crop, such as wheat, represents an effective way to preserve human health in developing countries. In the present work, a key enzyme involved in the branch of carotenoids pathway producing β-carotene, lycopene epsilon cyclase, has been targeted by a TILLING approach in a “Block strategy” perspective. The null mutant genotype showed a strong reduction in the expression of lcyE gene and also interesting pleiotropic effects on an enzyme (β-ring hydroxylase) acting downstream in the pathway. Biochemical profiling of carotenoids in the wheat mutant lines showed an increase of roughly 75% in β-carotene in the grains of the complete mutant line vs. the control. In conclusions, here we describe the production and the characterization of a new wheat line biofortified in provitamin A obtained through a non-transgenic approach also shading new light on the molecular mechanism governing carotenoids biosynthesis in durum wheat.