Phytosiderophores determine thresholds for iron and zinc accumulation in biofortified rice endosperm while inhibiting the accumulation of cadmium.
Phytosiderophores determine thresholds for iron and zinc accumulation in biofortified rice endosperm while inhibiting the accumulation of cadmium.
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DOI：
10.1093/jxb/erx304
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发表时间：
2017-10-13
影响因子：
6.9
通讯作者：
Christou P
中科院分区：
文献类型：
--
作者：
Banakar R;Alvarez Fernandez A;Díaz-Benito P;Abadia J;Capell T;Christou P
我们揭示了水稻胚乳中铁和锌积累上限的机制，同时抑制了镉的积累。烟胺（NA）和2 ' -脱氧酸（DMA）是促进金属在水稻胚乳中积累的金属螯合配体，但这些植物铁载体如何调节不同金属的水平并限制其积累尚不清楚。在本研究中，产生高水平NA和DMA的转基因水稻胚乳中积累的铁（Fe）和锌（Zn）分别是野生型植株的4倍和2倍。铁和锌在营养组织中的分布表明，这两种金属作为一种缓冲机制被隔离，以避免种子过载。这种缓冲机制涉及到根和地上营养组织中编码金属转运蛋白的基因的调节。转基因植株的胚乳在积累更多的铁和锌的同时，镉（Cd）的积累较少，表明较高的铁和锌水平竞争性地抑制了镉的积累。我们的数据表明，尽管铁（~22.5µg g−1干重）和锌（~84µg g−1干重）在胚乳中的积累有严格的上限，但精心选择增加必需矿物质的策略也可以限制镉等有毒金属的积累，从而进一步提高水稻的营养价值。
We unravel the mechanisms that set upper limits for iron and zinc accumulation in rice endosperm while inhibiting the accumulation of cadmium. Nicotianamine (NA) and 2′-deoxymugenic acid (DMA) are metal-chelating ligands that promote the accumulation of metals in rice endosperm, but it is unclear how these phytosiderophores regulate the levels of different metals and limit their accumulation. In this study, transgenic rice plants producing high levels of NA and DMA accumulated up to 4-fold more iron (Fe) and 2-fold more zinc (Zn) in the endosperm compared with wild-type plants. The distribution of Fe and Zn in vegetative tissues suggested that both metals are sequestered as a buffering mechanism to avoid overloading the seeds. The buffering mechanism involves the modulation of genes encoding metal transporters in the roots and aboveground vegetative tissues. As well as accumulating more Fe and Zn, the endosperm of the transgenic plants accumulated less cadmium (Cd), suggesting that higher levels of Fe and Zn competitively inhibit Cd accumulation. Our data show that although there is a strict upper limit for Fe (~22.5 µg g−1 dry weight) and Zn (~84 µg g−1 dry weight) accumulation in the endosperm, the careful selection of strategies to increase endosperm loading with essential minerals can also limit the accumulation of toxic metals such as Cd, thus further increasing the nutritional value of rice.
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影响因子：
6.4
作者：
Hazama, Kenji;Nagata, Shinji;Yoneyama, Tadakatsu
通讯作者：
Yoneyama, Tadakatsu
影响因子：
2.8
作者：
Lan, Hong-Xia;Wang, Zhou-Fei;Zhang, Hong-Sheng
通讯作者：
Zhang, Hong-Sheng
DOI：
10.2183/pjab.86.900
发表时间：
2010
期刊：
Proceedings of the Japan Academy. Series B, Physical and biological sciences
影响因子：
--
作者：
Kobayashi T;Nakanishi H;Nishizawa NK
通讯作者：
Nishizawa NK
DOI：
10.1038/nbt1091-957
发表时间：
1991-10-01
期刊：
BIO-TECHNOLOGY
影响因子：
--
作者：
CHRISTOU, P;FORD, TL;KOFRON, M
通讯作者：
KOFRON, M
影响因子：
6.9
作者：
Ishimaru, Y;Suzuki, M;Nishizawa, NK
通讯作者：
Nishizawa, NK