Genetic engineering approaches to improve the bioavailability and the level of iron in rice grains
Genetic engineering approaches to improve the bioavailability and the level of iron in rice grains
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DOI：
10.1007/s001220051659
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发表时间：
2001-02-01
影响因子：
5.4
通讯作者：
Potrykus, I
中科院分区：
文献类型：
--
作者：
Lucca, P;Hurrell, R;Potrykus, I
铁缺乏症是世界范围内最普遍的微量营养素缺乏症。一个主要的原因是从谷物和豆类为基础的饮食中吸收铁的植酸高。我们已经探索了三种方法来增加从米饭中吸收的铁的量。我们首先将来自菜豆的铁蛋白基因导入水稻谷粒，使其铁含量增加了两倍。为了提高铁的生物利用率，我们将烟曲霉的耐热植酸酶导入水稻胚乳。此外，由于半胱氨酸肽被认为是铁吸收的主要增强剂，我们过表达内源性富含半胱氨酸的金属硫蛋白样蛋白。半胱氨酸残基的含量增加了约7倍，谷物中的植酸酶水平增加了约130倍，在模拟消化实验中，植酸酶的活性足以完全降解植酸。高植酸酶水稻具有较高的铁含量和丰富的半胱氨酸肽，有可能大大改善食稻人群的铁营养。
Iron deficiency is the most widespread micro-nutrient deficiency world-wide. A major cause is the poor absorption of iron from cereal and legume-based diets high in phytic acid. We have explored three approaches for increasing the amount of iron absorbed from rice-based meals. We first introduced a ferritin gene from Phaseolus vulgaris into rice grains, increasing their iron content up to two-fold. To increase iron bioavailability, we introduced a thermotolerant phytase from Aspergillus fumigatus into the rice endosperm. In addition, as cysteine peptides are considered a major enhancer of iron absorption, we overexpressed the endogenous cysteine-rich metallothionein-like protein. The content of cysteine residues increased about seven-fold and the phytase level in the grains about 130-fold, giving a phytase activity sufficient to completely degrade phytic acid in a simulated digestion experiment. High phytase rice, with an increased iron content and rich in cysteine-peptide, has the potential to greatly improve iron nutrition in rice-eating populations.