Betacarotene (βC) is one of the mostimportant pigments on Earth. Plants use βC as an antioxidant, notably rightinside the photosynthetic centres. Significant amounts are found in green leafyvegetable, carrots, sweet potato etc. The green alga Dunaliella accumulates enough βC for commercial production (mentionedin Leaf 36 https://lnkd.in/dkK5PbqF).
βC is very important in animal diets, where it gets metabolized to retinol, better known as Vitamin A (Vit A). In humans Vit Adeficiency has several severe consequences, including blindness and mortality from measles. These can be prevented by Vit A supplements or by adequate βC in the diet.
Vit A deficiency is rare for people with access to fresh vegetables or vitamin supplements, but prevalent in parts of SE Asia and Sub-Saharan Africa where people subsist largely on grains and other dried food. Golden Rice was created to answer their needs. This noble goal has been supported by philanthropic organisations (Gates Foundation, Helen Keller Foundation).
#Goldenrice has high β Cin the edible rice endosperm. This was achieved by insertion of two genes, for phytoene synthase (psy, from daffodil) and for lycopene desaturase (crtl, bacterial). Rice already has its own lycopenecyclase (lcy) to complete the synthesis of βC (see Wikipedia article). A later development was to insert psy from maize instead of daffodil, resulting in a 23-fold βC increase!
While an there is significant resistance(GRAIN 2018), Golden Rice is an excellent demonstration of what geneticengineering can achieve,
Further reading
Stevens, Gretchen A et al. (2015). Trends and mortality effects of vitamin A deficiencyin children in 138 low-income and middle-income countries between 1991 and2013: a pooled analysis of population-based surveys. The Lancet. Global health, 3(9), e528–e536. https://doi.org/10.1016/S2214-109X(15)00039-X
Wikipedia (2022), Golden rice. https://en.wikipedia.org/w/index.php?title=Golden_rice&oldid=1095744189.
GRAIN, MASIPAG and Stop Golden Rice! Network/ 21 Nov 2018, Seeds https://grain.org/en/article/6067-don-t-get-fooled-again-unmasking-two-decades-of-lies-about-golden-rice#
