Constitutive expression of a barley Fe phytosiderophore transporter increases alkaline soil tolerance and results in iron partitioning between vegetative and storage tissues under stress
Constitutive expression of a barley Fe phytosiderophore transporter increases alkaline soil tolerance and results in iron partitioning between vegetative and storage tissues under stress
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DOI：
10.1016/j.plaphy.2012.01.009
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发表时间：
2012-04-01
影响因子：
6.5
通讯作者：
Christou, Paul
中科院分区：
文献类型：
--
作者：
Gomez-Galera, Sonia;Sudhakar, Duraialagaraja;Christou, Paul
谷物已经进化出螯合系统来动员土壤中的不溶性铁，但在水稻中，这一过程效率相当低，使作物对碱性土壤非常敏感。因此，我们设计水稻表达大麦铁-植物铁素载体（HvYS1），使大麦能够从碱性土壤中吸收铁。在标准土壤（pH 5.5）和碱性土壤（pH 8.5）中培养具有代表性的转基因水稻品系，评价其耐碱性和铁动员能力。转基因植株在标准土壤中生长时，虽然叶片和种子中的铁浓度与野生型相似，但仍能发育出次生分蘖并结籽。然而，在碱性土壤中生长时，转基因植株的生长、产量和叶片铁浓度均高于野生型植株，而野生型植株发育严重迟缓。与野生型相比，转基因植物从碱性土壤中吸收铁的效率更高，表明其增加铁迁移的能力增强。有趣的是，所有额外的铁都在营养组织中积累，即野生型和转基因植物种子中的铁浓度没有差异。我们的数据表明，通过表达HvYS1可以增强根际铁的吸收，并证实了在胁迫下将铁转移到叶片而不是种子的分配机制。(C) 2012 Elsevier Masson SAS。版权所有。
Cereals have evolved chelation systems to mobilize insoluble iron in the soil, but in rice this process is rather inefficient, making the crop highly susceptible to alkaline soils. We therefore engineered rice to express the barley iron-phytosiderophore transporter (HvYS1), which enables barley plants to take up iron from alkaline soils. A representative transgenic rice line was grown in standard (pH 5.5) or alkaline soil (pH 8.5) to evaluate alkaline tolerance and iron mobilization. Transgenic plants developed secondary tillers and set seeds when grown in standard soil although iron concentration remained similar in leaves and seeds compared to wild type. However, when grown in alkaline soil transgenic plants exhibited enhanced growth, yield and iron concentration in leaves compared to the wild type plants which were severely stunted. Transgenic plants took up iron more efficiently from alkaline soil compared to wild type, indicating an enhanced capacity to increase iron mobility ex situ. Interestingly, all the additional iron accumulated in vegetative tissues, i.e. there was no difference in iron concentration in the seeds of wild type and transgenic plants. Our data suggest that iron uptake from the rhizosphere can be enhanced through expression of HvYS1 and confirm the operation of a partitioning mechanism that diverts iron to leaves rather than seeds, under stress. (C) 2012 Elsevier Masson SAS. All rights reserved.