Fighting iron deficiency anemia with iron-rich rice.
OBJECTIVE
Iron deficiency is estimated to affect about 30% of the world population. Iron supplementation in the form of tablets and food fortification has not been successful in developing countries, and iron deficiency is still the most important deficiency related to malnutrition. Here we present experiments that aim to increase the iron content in rice endosperm and to improve its absorption in the human intestine by means of genetic engineering.


METHODS
We first introduced a ferritin gene from Phaseolus vulgaris into rice grains, increasing their iron content up to twofold. To increase iron bioavailability, we introduced a thermo-tolerant phytase from Aspergillus fumigatus into the rice endosperm. In addition, as cysteine peptides are considered major enhancers of iron absorption, we over-expressed the endogenous cysteine-rich metallothionein-like protein.


RESULTS
The content of cysteine residues increased about sevenfold and the phytase level in the grains about one hundred and thirtyfold, giving a phytase activity sufficient to completely degrade phytic acid in a simulated digestion experiment.


CONCLUSIONS
This rice, with higher iron content, rich in phytase and cysteine-peptide has a great potential to substantially improve iron nutrition in those populations where iron deficiency is so widely spread.
Lucca
Paola
P
Institute for Plant Science ETHZ, Zurich, Switzerland. paola.lucca@irb.unisi.ch
Hurrell
Richard
R
Potrykus
Ingo
I
D010832:6-Phytase / Q000235:genetics; D018798:Anemia, Iron-Deficiency / Q000178:diet therapy* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005293:Ferritins / Q000235:genetics; D006801:Humans; D019266:Iron, Dietary / Q000378:metabolism*; D008667:Metalloproteins / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified / Q000378:metabolism*; D012639:Seeds / Q000235:genetics* / Q000378:metabolism*; D013054:Spectrophotometry, Atomic
D019266:Iron, Dietary; D008667:Metalloproteins; D010940:Plant Proteins; C094564:metallothionein-like protein, Brassica campestris; D005293:Ferritins; D010832:6-Phytase