A TRANSGENIC CEREAL CROP WITH ENHANCED FOLATE: RICE EXPRESSING WHEAT HPPPK/DHPS

摘要

Folate is a B-group vitamin critical for normal cellular function and division. It acts in one-carbon transfer systems essential in nucleotide synthesis, methylation and gene expression. Insufficient folate intake causes megaloblastic anaemia and is linked to cardiovascular disease, various cancers and cognitive decline. Low prenatal folate levels can lead to low birth weight and premature infants, as well as catastrophic neural tube defects including spina bifida and anencephaly (MRC Vitamin Study Research Group 1991, Snowden et al 2000, McCullough et al 2004). Vertebrates are unable to synthesize folate de novo, accordingly plant foods are the primary source. Cereals, which provide 80% of dietry intake to over half the worlds population, are particularly poor in folate. Consequently the majority of developed nations have fortification programmes. In the developing world however, such programmes are logistically far more difficult. A practicable alternative is to use metabolic engineering to create a cereal crop plant producing high levels of folate.