Iron deficiency affects nitrogen metabolism in cucumber (Cucumis sativus L.) plants.
Iron deficiency affects nitrogen metabolism in cucumber (Cucumis sativus L.) plants.
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DOI：
10.1186/1471-2229-12-189
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发表时间：
2012-10-11
影响因子：
5.3
通讯作者：
Zocchi G
中科院分区：
文献类型：
--
作者：
Borlotti A;Vigani G;Zocchi G
氮素是植物生长发育的主要限制性营养元素。在可能限制NO3-同化的因素中，Fe作为还原同化途径酶的金属辅因子可能起着至关重要的作用。关于缺铁条件下策略I植物氮代谢变化的研究很少。以黄瓜（Cucumis sativus L.）植物在缺铁条件下生长时会改变其氮代谢。研究了缺铁黄瓜根和叶中硝酸盐还原同化酶的活性以及产生铵同化底物的反应。在缺铁条件下，只有硝酸还原酶（EC 1.7.1.1）活性在根和叶水平上均下降，而谷氨酰胺合成酶（EC 6.3.1.2）和谷氨酸合成酶（EC 1.4.1.14）活性则有所增加，因此，对这些酶的转录本分析表明，除根硝酸还原酶活性增加外，其余酶的活性均下降。此外，它被发现，氨基酸浓度大大降低，在缺铁的根，而它在相应的叶片增加。缺铁植株木质部汁液中氨基酸含量增加。在这项工作中获得的数据提供了新的见解植物缺铁的反应，表明这种营养失调差异影响根和叶中的N代谢。事实上，在缺铁的情况下，根的反应更有效，通过向叶提供代谢物（即aa，有机酸）来维持整个植物。
Nitrogen is a principal limiting nutrient in plant growth and development. Among factors that may limit NO3- assimilation, Fe potentially plays a crucial role being a metal cofactor of enzymes of the reductive assimilatory pathway. Very few information is available about the changes of nitrogen metabolism occurring under Fe deficiency in Strategy I plants. The aim of this work was to study how cucumber (Cucumis sativus L.) plants modify their nitrogen metabolism when grown under iron deficiency. The activity of enzymes involved in the reductive assimilation of nitrate and the reactions that produce the substrates for the ammonium assimilation both at root and at leaf levels in Fe-deficient cucumber plants were investigated. Under Fe deficiency, only nitrate reductase (EC 1.7.1.1) activity decreased both at the root and leaf level, whilst for glutamine synthetase (EC 6.3.1.2) and glutamate synthase (EC 1.4.1.14) an increase was found. Accordingly, the transcript analysis for these enzymes showed the same behaviour except for root nitrate reductase which increased. Furthermore, it was found that amino acid concentration greatly decreased in Fe-deficient roots, whilst it increased in the corresponding leaves. Moreover, amino acids increased in the xylem sap of Fe-deficient plants. The data obtained in this work provided new insights on the responses of plants to Fe deficiency, suggesting that this nutritional disorder differentially affected N metabolism in root and in leaf. Indeed under Fe deficiency, roots respond more efficiently, sustaining the whole plant by furnishing metabolites (i.e. aa, organic acids) to the leaves.
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影响因子：
4.3
作者：
Kaiser, WM;Kandlbinder, A;Glaab, J
通讯作者：
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影响因子：
6.5
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Hodges, M
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6.9
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通讯作者：
Zocchi, G
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6.9
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通讯作者：
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