Organic nitrogen uptake by plants: reevaluation by position-specific labeling of amino acids
Organic nitrogen uptake by plants: reevaluation by position-specific labeling of amino acids
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DOI：
10.1007/s10533-015-0130-3
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发表时间：
2015-09-01
期刊：
影响因子：
4
通讯作者：
Kuzyakov, Yakov
中科院分区：
文献类型：
--
作者：
Moran-Zuloaga, Daniel;Dippold, Michaela;Kuzyakov, Yakov
目前的研究表明，许多植物不仅能够吸收无机氮（N），而且能够吸收有机氮。我们使用了新的工具，位置特异性同位素标记，以提高完整的氨基酸摄取的定量和加深我们的理解发生在根-土壤-微生物界面的过程。位置特异性的C-14和N-15标记的丙氨酸使我们能够跟踪玉米，白羽扇豆和菊苣从单个分子位置的C的吸收。应用均匀C-14标记的丙氨酸和乙酸盐以及无机（NH 4）-N-15（+）和（NO3）-N-15（-）作为对照。均匀的C-14标记的丙氨酸和乙酸的平等吸收表明，植物吸收的低分子量有机物质（LMWOS）是独立的分子中的N。C-14摄取从单个分子位置的丙氨酸强烈不同：这证实了土壤微生物裂解丙氨酸在6小时内转化产物，然后采取了植物。微生物的利用强烈地超过了农业土壤中植物对LMWOS的吸收。这项研究表明，位置特异性标记是一种创新的工具，使完整的吸收分子片段的吸收分离，并提高了竞争过程中的LMWOS利用在根际的理解。
Current studies suggest that many plants are able to take up not only inorganic nitrogen (N) but also organic N. We used the novel tool of position-specific isotope labeling to improve the quantification of intact amino acid uptake and to deepen our understanding of the processes occurring at the root-soil-microorganism interface. Position-specific C-14 and N-15 labeled alanine enabled us to trace the uptake of C from individual molecule positions by Zea mays, Lupinus albus and Cichorium intybus. Uniformly C-14 labeled alanine and acetate and inorganic (NH4)-N-15 (+) and (NO3)-N-15 (-) were applied as controls. Equal uptake of uniformly C-14 labeled alanine and acetate showed that plant uptake of low molecular weight organic substances (LMWOS) is independent of N in the molecule. C-14 uptake from individual molecule positions of alanine strongly differed: this confirmed that soil microorganisms cleaved alanine within 6 h into transformation products, which were then taken up by the plants. Microbial utilization strongly outcompeted the plant uptake of LMWOS in agricultural soils. This study revealed that position-specific labeling is an innovative tool that enables separation of the intact uptake from the uptake of molecule fragments and improves the understanding of competing processes for LMWOS utilization in the rhizosphere.