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Rice (Oryza sativa), a major staple food, is usually milled to remove the oil-rich aleurone layer that turns rancid upon storage, especially in tropical areas. The remaining edible part of rice grains, the endosperm, lacks several essential nutrients, such as provitamin A. Thus, predominant rice consumption promotes vitamin A deficiency, a serious public(More)
Strigolactones, phytohormones with diverse signaling activities, have a common structure consisting of two lactones connected by an enol-ether bridge. Strigolactones derive from carotenoids via a pathway involving the carotenoid cleavage dioxygenases 7 and 8 (CCD7 and CCD8) and the iron-binding protein D27. We show that D27 is a β-carotene isomerase that(More)
We here report on the characterization of a novel third phytoene synthase gene (PSY) in rice (Oryza sativa), OsPSY3, and on the differences among all three PSY genes with respect to the tissue-specific expression and regulation upon various environmental stimuli. The two already known PSYs are under phytochrome control and involved in carotenoid(More)
Strigolactones (SLs) are a class of phytohormones and rhizosphere signaling compounds with high structural diversity. Three enzymes, carotenoid isomerase DWARF27 and carotenoid cleavage dioxygenases CCD7 and CCD8, were previously shown to convert all-trans-β-carotene to carlactone (CL), the SL precursor. However, how CL is metabolized to SLs has remained(More)
BACKGROUND Since the creation of "Golden Rice", biofortification of plant-derived foods is a promising strategy for the alleviation of nutritional deficiencies. Potato is the most important staple food for mankind after the cereals rice, wheat and maize, and is extremely poor in provitamin A carotenoids. METHODOLOGY We transformed potato with a(More)
The strigolactones are rhizosphere signaling molecules as well as a new class of plant hormones with a still increasing number of biological functions being uncovered. Here, we review a recent major breakthrough in our understanding of strigolactone biosynthesis, which has revealed the unexpected simplicity of the originally postulated complex pathway.(More)
Provitamin A accumulates in the grain of Golden Rice as a result of genetic transformation. In developing countries, where vitamin A deficiency prevails, grain from Golden Rice is expected to provide this important micronutrient sustainably through agriculture. Since its original production, the prototype Golden Rice has undergone intense research to(More)
Vitamin-A deficiency (VAD) is a major malnutrition problem in South Asia, where indica rice is the staple food. Indica-type rice varieties feed more than 2 billion people. Hence, we introduced a combination of transgenes using the biolistic system of transformation enabling biosynthesis of provitamin A in the endosperm of several indica rice cultivars(More)
To obtain a functioning provitamin A (beta-carotene) biosynthetic pathway in rice endosperm, we introduced in a single, combined transformation effort the cDNA coding for phytoene synthase (psy) and lycopene beta-cyclase (beta-lcy) both from Narcissus pseudonarcissus and both under the control of the endosperm-specific glutelin promoter together with a(More)
Enzymes that produce retinal and related apocarotenoids constitute a sequence- and thus structure-related family, a member of which was analyzed by x-ray diffraction. This member is an oxygenase and contains an Fe2+-4-His arrangement at the axis of a seven-bladed beta-propeller chain fold covered by a dome formed by six large loops. The Fe2+ is accessible(More)