Arabidopsis Transporter MGT6 Mediates Magnesium Uptake and Is Required for Growth under Magnesium Limitation
Arabidopsis Transporter MGT6 Mediates Magnesium Uptake and Is Required for Growth under Magnesium Limitation
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拟南芥转运蛋白 MGT6 介导镁吸收，是镁限制下生长所必需的
DOI：
10.1105/tpc.114.124628
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发表时间：
2014-05-01
期刊：
影响因子：
11.6
通讯作者：
Luan, Sheng
中科院分区：
文献类型：
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作者：
Mao, Dandan;Chen, Jian;Luan, Sheng
虽然镁是植物细胞中含量最丰富的二价阳离子，但对植物根系吸收镁的机制知之甚少。在这里，我们报道了镁转运蛋白6(MGT6)/线粒体RNA剪接2-4在拟南芥对镁离子的吸收和低镁耐性中的一个关键功能。当土壤或生长介质中的镁离子水平较高时，MGT6主要在植物的气生组织中表达。在缺镁条件下，MGT6在根中的表达水平较高，提示MGT6在响应根中的低镁状态中起着一定的作用。在低镁条件下，RNA干扰(RNAi)沉默转基因植株中的MGT6，导致植株生长迟缓，RNAi植株转入镁充足的培养基后，表型恢复正常生长。与野生型植株相比，RNAi植株在低镁离子条件下含有较低的镁离子水平，但在镁离子充足的条件下不含镁离子。进一步分析表明，MGT6定位于质膜上，在镁限制下根系对镁的吸收起着关键作用。我们的结论是，MGT6介导了根对镁的吸收，是植物适应低镁环境所必需的。
Although magnesium (Mg2+) is the most abundant divalent cation in plant cells, little is known about the mechanism of Mg2+ uptake by plant roots. Here, we report a key function of Magnesium Transport6 (MGT6)/Mitochondrial RNA Splicing2-4 in Mg2+ uptake and low-Mg2+ tolerance in Arabidopsis thaliana. MGT6 is expressed mainly in plant aerial tissues when Mg2+ levels are high in the soil or growth medium. Its expression is highly induced in the roots during Mg2+ deficiency, suggesting a role for MGT6 in response to the low-Mg2+ status in roots. Silencing of MGT6 in transgenic plants by RNA interference (RNAi) resulted in growth retardation under the low-Mg2+ condition, and the phenotype was restored to normal growth after RNAi plants were transferred to Mg2+ -sufficient medium. RNAi plants contained lower levels of Mg2+ compared with wild-type plants under low Mg2+ but not under Mg2+ -sufficient conditions. Further analysis indicated that MGT6 was localized in the plasma membrane and played a key role in Mg2+ uptake by roots under Mg2+ limitation. We conclude that MGT6 mediates Mg2+ uptake in roots and is required for plant adaptation to a low-Mg2+ environment.