* •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.
(private-note)Under Fe deficiency, Zn and manganese (Mn) concentrations strongly increased, particularly in OL, which was probably caused by the up-regulation of the Fe acquisition machinery (von Wirén et al., 1994; Vert et al., 2002)
%0 Journal Article
%1 citeulike:13054799
%A Shi, Rongli
%A Weber, Günther
%A Köster, Jessica
%A Reza-Hajirezaei, Mohammad
%A Zou, Chunqin
%A Zhang, Fusuo
%A von Wirén, Nicolaus
%D 2012
%I Blackwell Publishing Ltd
%J New Phytologist
%K citeulikeExport nutrients, wheat
%N 2
%P 372--383
%R 10.1111/j.1469-8137.2012.04165.x
%T Senescence-induced iron mobilization in source leaves of barley (Hordeum vulgare) plants
%U http://dx.doi.org/10.1111/j.1469-8137.2012.04165.x
%V 195
%X * •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.
@article{citeulike:13054799,
abstract = {{* •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.}},
added-at = {2019-03-31T01:14:40.000+0100},
author = {Shi, Rongli and Weber, G\"{u}nther and K\"{o}ster, Jessica and Reza-Hajirezaei, Mohammad and Zou, Chunqin and Zhang, Fusuo and von Wir\'{e}n, Nicolaus},
biburl = {https://www.bibsonomy.org/bibtex/24a657caf74d50fd694bccda45d32367b/dianella},
citeulike-article-id = {13054799},
citeulike-linkout-0 = {http://dx.doi.org/10.1111/j.1469-8137.2012.04165.x},
comment = {(private-note)Under Fe deficiency, Zn and manganese (Mn) concentrations strongly increased, particularly in OL, which was probably caused by the up-regulation of the Fe acquisition machinery (von Wir\'{e}n et al., 1994; Vert et al., 2002)},
day = 1,
doi = {10.1111/j.1469-8137.2012.04165.x},
interhash = {e8851acbb9b3d6e91e04a00ec10c29b7},
intrahash = {4a657caf74d50fd694bccda45d32367b},
journal = {New Phytologist},
keywords = {citeulikeExport nutrients, wheat},
month = jul,
number = 2,
pages = {372--383},
posted-at = {2014-02-20 04:36:30},
priority = {2},
publisher = {Blackwell Publishing Ltd},
timestamp = {2019-03-31T01:16:26.000+0100},
title = {{Senescence-induced iron mobilization in source leaves of barley (Hordeum vulgare) plants}},
url = {http://dx.doi.org/10.1111/j.1469-8137.2012.04165.x},
volume = 195,
year = 2012
}