Beta-carotene | DDW The Colour House

Effects of a Combination of Beta Carotene and Vitamin A on Lung Cancer and Cardiovascular Disease
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ENHANCING B-CAROTENE PRODUCTION IN THE RED RICE …

Beta-carotene plays a key role for us because it can be converted to vitamin A after it is taken in. Vitamin A is a necessary nutrient for the visual and immune system, especially for children and pregnant women. The goal of the Golden Rice project was to give people a new resource of vitamin A and reduce deficiencies. Vitamin A deficiency: The original goal of the Golden Rice research is to fight against a global food issue, shortage of dietary vitamin A. Vitamin A deficiency is more common in less developed areas because of the unbalanced food supply. It is estimated to be affecting about 130 million pre-school children and pregnant mothers (Fig 2). Symptoms of vitamin A deficiency include Xerophthalmia, night blindness, or complete blindness. The deficiency can also kill children by impacting the immune system. Children suffering from vitamin A deficiency become weak against infectious diseases like measles. Golden Rice gives a possibility to provide people a new source of vitamin A, especially for those who can’t afford other high value resources of vitamin A.

Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm
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ENHANCING B-CAROTENE PRODUCTION IN THE RED ..

All plant tissues that accumulate high levels of carotenoids have mechanisms for carotenoid sequestration, including crystallisation, oil deposition, membrane proliferation or protein-lipid sequestration. It has been shown that lipid accumulation can be a driver of carotenoid formation by acting as a lipophilic sink (Rabbani et al., 1998). The non-carotenogenic starchy rice endosperm, on the other hand, is very low in lipid and apparently lacks any such means for carotenoid deposition. It was also doubtful whether would have the necessary precursors for carotene biosynthesis present and available in the grains, with many believing that the whole, multi-step carotenoid biosynthetic pathway was completely absent from the endosperm.

Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm
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This fat-soluble vitamin occurs in the form of Retinol (from animal sources) and vitamin A precursors called carotenoids (from plant sources). Vitamin A is essential for vision, normal growth and tissue differentiation. Its beta-carotene form is also an important anti-oxidant to protect the cells from oxidative damage.

Golden Rice: Introducing the -Carotene Biosynthesis Pathway into Rice Endosperm by Genetic Engineering to Defeat Vitamin A Deficiency
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Why the Rice We Eat Lacks Beta-Carotene - …

Golden Rice: Golden Rice is a variety of Asian rice, Oryza sativa (Fig 1). This variety was bred through genetic engineering. The most essential characteristic of this type of rice is its ability to biosynthesize beta-carotene. As a result of genetic modification, endosperm (the tissue surrounds embryo and provides nutrition) of Golden rice contains beta-carotene, giving the rice grain a golden color. Common beta-carotene containers, like carrot and papaya, are also filled by this important compound and share the same color.

Beta-carotene synthesis pathway in rice.

The need for CRTI apparently conflicts with the presence of PDS and ZDS transcripts in wild-type endosperm, as shown by quantitative RT-PCR analyses. This could be due to low level presence of the enzyme rather than its mRNA. Due to the low-level expression, the complex reaction mechanisms of PDS and ZDS, and the unavailability of radioactive carotene substrates, the investigations were done using a transgenic approach rather than in vitro reactions. The tissue-specific expression of the PDS/ZDS system, instead of CRTI, in rice endosperm resulted in the formation of coloured carotenoids, showing that the rice endosperm provides the complex requirements for the activity of the plant desaturases.

07/01/2018 · beta-carotene synthesis into rice

The explanation is that enzymes further down the pathway, such as lycopene cyclases (LCYs) and α- and β-carotene hydroxylases (HYDs), are still being produced in wild-type rice endosperm, while PSY and one or both of the plant carotene desaturases —phytoene desaturase (PDS) and ζ-carotene desaturase (ZDS)— as well as the cis-trans isomerases, namely ζ-carotene cis-trans Isomerase (Z-ISO; Chen et al., 2010) and carotene cis-trans isomerase (CRTISO; Isaacson et al., 2002; Park et al., 2002; Yu et al., 2011) are not. Synthesis of lycopene by PSY and CRTI in transgenic plants provides the substrate for these downstream enzymes and consequently enables the formation of the observed products.

the beta-carotene in golden rice: ..

Beta-carotene plays a key role for us because it can be converted to vitamin A after it is taken in. Vitamin A is a necessary nutrient for the visual and immune system, especially for children and pregnant women. The goal of the Golden Rice project was to give people a new resource of vitamin A and reduce deficiencies.