Iron-biofortification in rice by the introduction of three barley genes participated in mugineic acid biosynthesis with soybean ferritin gene.
Iron-biofortification in rice by the introduction of three barley genes participated in mugineic acid biosynthesis with soybean ferritin gene.
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DOI：
10.3389/fpls.2013.00132
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发表时间：
2013
影响因子：
5.6
通讯作者：
Nishizawa NK
中科院分区：
文献类型：
--
作者：
Masuda H;Kobayashi T;Ishimaru Y;Takahashi M;Aung MS;Nakanishi H;Mori S;Nishizawa NK
缺铁在全世界都是一个严重的问题，尤其是在发展中国家。铁生物强化大米的生产将有助于改善这一问题。在此之前，利用胚乳特异性启动子在水稻中表达铁蛋白（铁蛋白）可使转基因种子中的铁浓度增加两倍。然而，铁蛋白的进一步过表达并没有产生种子铁浓度的额外增加，并且在转基因植株的叶片中发现了铁缺乏的症状。在本研究中，我们的目标是通过铁螯合剂mugineic酸促进铁的吸收和运输，从而进一步提高水稻种子中的铁浓度，而不增加对缺铁的敏感性。为此，我们引入了由两个胚乳特异性启动子驱动的大豆铁蛋白基因（SoyferH2），以及大麦烟胺合成酶基因（HvNAS1）、两个烟胺转氨酶基因（HvNAAT-A和-B）和一个mugine酸合成酶基因（IDS3），以提高水稻mugine酸的产量。使用无标记媒介作为提高公众接受度的手段。根据抛光种子铁浓度和铁蛋白积累情况，从102个突变体中筛选出代表性品系。这些品系在商业供应的土壤（铁充足的条件）和钙质土壤（铁缺乏的条件）中生长。同时表达铁蛋白和镁酸生物合成基因的品系在钙质土壤中表现出耐缺铁的迹象。处理后的T3种子铁浓度分别比正常土壤和钙质土壤中的非转基因品系提高了4倍和2.5倍。上述结果表明，在限铁条件下，铁蛋白基因和镁酸生物合成基因的同时引入能有效提高种子铁水平，且不会引起铁敏感性。
Iron deficiency is a serious problem around the world, especially in developing countries. The production of iron-biofortified rice will help ameliorate this problem. Previously, expression of the iron storage protein, ferritin, in rice using an endosperm-specific promoter resulted in a two-fold increase in iron concentration in the resultant transgenic seeds. However, further over expression of ferritin did not produce an additional increase in the seed iron concentration, and symptoms of iron deficiency were noted in the leaves of the transgenic plants. In the present study, we aimed to further increase the iron concentration in rice seeds without increasing the sensitivity to iron deficiency by enhancing the uptake and transport of iron via a ferric iron chelator, mugineic acid. To this end, we introduced the soybean ferritin gene (SoyferH2) driven by two endosperm-specific promoters, along with the barley nicotianamine synthase gene (HvNAS1), two nicotianamine aminotransferase genes (HvNAAT-A and -B), and a mugineic acid synthase gene (IDS3) to enhance mugineic acid production in rice plants. A marker-free vector was utilized as a means of increasing public acceptance. Representative lines were selected from 102 transformants based on the iron concentration in polished seeds and ferritin accumulation in the seeds. These lines were grown in both commercially supplied soil (iron-sufficient conditions) and calcareous soil (iron-deficient conditions). Lines expressing both ferritin and mugineic acid biosynthetic genes showed signs of iron-deficiency tolerance in calcareous soil. The iron concentration in polished T3 seeds was increased by 4 and 2.5 times, as compared to that in non-transgenic lines grown in normal and calcareous soil, respectively. These results indicate that the concomitant introduction of the ferritin gene and mugineic acid biosynthetic genes effectively increased the seed iron level without causing iron sensitivity under iron-limited conditions.
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影响因子：
4.8
作者：
Masuda, T;Goto, F;Yoshihara, T
通讯作者：
Yoshihara, T
影响因子：
4.3
作者：
Kobayashi, T;Nakanishi, H;Mori, S
通讯作者：
Mori, S
影响因子：
5.5
作者：
Bashir, Khurram;Ishimaru, Yasuhiro;Nishizawa, Naoko K.
通讯作者：
Nishizawa, Naoko K.
影响因子：
7.2
作者：
Higuchi, K;Watanabe, S;Mori, S
通讯作者：
Mori, S
影响因子：
5.1
作者：
Inoue, Haruhiko;Takahashi, Michiko;Nishizawa, Naoko K.
通讯作者：
Nishizawa, Naoko K.