期刊
NEW PHYTOLOGIST
卷 195, 期 2, 页码 372-383出版社
WILEY-BLACKWELL
DOI: 10.1111/j.1469-8137.2012.04165.x
关键词
deoxymugineic acid (DMA); iron biofortification; iron chelates; iron efficiency; iron retranslocation; nicotianamine synthase; nitrogen nutrition; phloem transport
资金
- Deutsche Forschungsgemeinschaft, Bonn, Germany [Wi1728/6-3, 14-1]
- Bundesministerium fur Bildung und Forschung [0315458B]
- 973 project of National Natural Science Foundation of China [2009CB118605, 30871592]
- trilateral PLANT-KBBE Initiative
Retranslocation of iron (Fe) from source leaves to sinks requires soluble Fe binding forms. As much of the Fe is protein-bound and associated with the leaf nitrogen (N) status, we investigated the role of N in Fe mobilization and retranslocation under N deficiency- vs dark-induced leaf senescence. By excluding Fe retranslocation from the apoplastic root pool, Fe concentrations in source and sink leaves from hydroponically grown barley (Hordeum vulgare) plants were determined in parallel with the concentrations of potential Fe chelators and the expression of genes involved in phytosiderophore biosynthesis. N supply showed opposing effects on Fe pools in source leaves, inhibiting Fe export out of source leaves under N sufficiency but stimulating Fe export from source leaves under N deficiency, which partially alleviated Fe deficiency-induced chlorosis. Both triggers of leaf senescence, shading and N deficiency, enhanced NICOTIANAMINE SYNTHASE2 gene expression, soluble Fe pools in source leaves, and phytosiderophore and citrate rather than nicotianamine concentrations. These results indicate that Fe mobilization within senescing leaves is independent of a concomitant N sink in young leaves and that phytosiderophores enhance Fe solubility in senescing source leaves, favoring subsequent Fe retranslocation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据