Metabolic engineering of carotenoid accumulation by creating a metabolic sink
- 640 Downloads
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.
KeywordsCarotenoids Metabolic sink Carotenoid sequestering structures Chromoplasts Cauliflower Or gene
We thank X. Zhou for the photograph. We are grateful to many colleagues for their contribution to this work. This research was supported by USDA National Research Initiative Grants, ARS Headquarter Postdoctoral Research Associated Fund, the Triad Foundation, and Helen Graham Charitable Foundation.
- Al Babili S, Hartung W, Kleinig H, Beyer P (1999) CPTA modulates levels of carotenogenic proteins and their mRNAs and affects carotenoid and ABA content as well as chromoplast structure in Narcissus pseudonarcissus flowers. Plant Biol 1:607–612Google Scholar
- Brown CR, Culley D, Yang CP, Durst R, Wrolstad R (2005) Variation of anthocyanin and carotenoid contents and associated antioxidant values in potato breeding lines. J Am Soc Hortic Sci 130:174–180Google Scholar
- Hadley CW, Miller EC, Schwartz SJ, Clinton SK (2002) Tomatoes, lycopene, and prostate cancer: progress and promise. Exp Biol Med 227:869–880Google Scholar
- Lu S, Eck Van J, Zhou X, Lopez AB, O’Halloran DM, Cosman KM, Conlin BJ, Paolillo DJ, Garvin DF, Vrebalov J, Kochian LV, Kupper H, Earle ED, Cao J, Li L (2006) The cauliflower Or gene encodes a DnaJ cysteine-rich domain-containing protein that mediates high levels of beta-carotene accumulation. Plant Cell 18:3594–3605PubMedCrossRefGoogle Scholar
- Wurtzel ET (2004) Genomics, genetics, and biochemistry of maize carotneoid biosynthesis. In: Romeo J (ed) Recent Advances in Phytochemistry, vol 38. Elsevier Ltd., pp 85–110Google Scholar