Metabolic engineering of carotenoid accumulation by creating a metabolic sink

Authors: Li, Li; VAN ECK, JOYCE - BOYCE THOMPSON INSTITUTE

Submitted to: Transgenic Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2007
Publication Date: 7/6/2007
Citation: Li, L., Van Eck, J. 2007. Metabolic engineering of carotenoid accumulation by creating a metabolic sink. Transgenic Research 16:581-585.

Interpretive Summary: Plant carotenoids are the primary dietary source of provitamin A for humans. Biofortification of staple crops with increased levels of carotenoids is considered to be a very effective and sustainable approach to improve human nutrition and health. Current approach primarily relies on expression of the biosynthetic genes which in many cases limits our capacity to enhance carotenoids to significant levels. Our work demonstrates that creating a metabolic sink by inducing the formation of sequestering structures exerts a profound effect on carotenoid accumulation. We believe that manipulation of sink capacity along with catalytic activity is the promising strategy to maximally enhance carotenoid levels in staple crops to the levels required for optimal human nutrition and health.

Technical Abstract: Carotenoids are highly beneficial for human nutrition and health because they provide essential nutrients and important antioxidants in our diets. However, many food crops, especially the major staple crops contain only trace to low amounts of carotenoids. Although significant progress has been made in developing food crops rich in carotenoids by altering the expression of carotenoid biosynthetic genes, in many cases it has proved to be difficult to reach the desired levels of carotenoid enrichment. The recent identification and characterization of a novel gene mutation in cauliflower reveals that creating a metabolic sink to sequester carotenoids is an important mechanism to control carotenoid accumulation in plants. The successful demonstration of increased carotenoid accumulation in association with the formation of sink structures in transgenic crops offers a new and alternative approach to increase carotenoid content. Manipulation of the formation of metabolic sink along with the catalytic activity of the pathway may represent a promising strategy for maximally improving the nutritional quality of food crops.