浮萍（Lemna gibba L.）对铵离子同化作用的核磁共振研究

N NUCLEAR MAGNETIC RESONANCE STUDY OF AMMONIUM ION ASSIMILATION BY LEMNA GIBBA L.

作者信息

Monselise Edna Ben-Izhak, Kost Daniel, Porath Dan, Tal Moshe

机构信息

Department of Biology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel.

Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva 84105, Israel.

出版信息

New Phytol. 1987 Oct;107(2):341-345. doi: 10.1111/j.1469-8137.1987.tb00186.x.

DOI:10.1111/j.1469-8137.1987.tb00186.x

PMID:33873841

Abstract

N Nuclear magnetic resonance (NMR) spectroscopy was used to follow nitrogen assimilation and amino acid production in Lemna gibba L. exposed to 0.4 mM NH Cl solution for 24 h. NMR analysis of the N content of the treated plant tissues (aqueous extract) revealed N incorporation into glutamine (N-amide plus amino-N or amide-N only) and glutamic acid and no detectable free ammonium ion. Methionine sulphoximine (MSO), an inhibitor of glutamine synthetase, at 1.0 mM inhibited completely the incorporation of N. In the presence of 0.5 mM azaserine (AZA), a glutamate synthase inhibitor, the incorporation of N was detected only in the amide group of glutamine. The results confirm the involvement of the glutamine synthetase/glutamate synthase (GS/ GOG AT) pathway in the assimilation of ammonium ions.

摘要

利用核磁共振（NMR）光谱法追踪在0.4 mM NH₄Cl溶液中处理24小时的浮萍（Lemna gibba L.）的氮同化和氨基酸生成情况。对处理过的植物组织（水提取物）的氮含量进行NMR分析，结果显示氮被掺入谷氨酰胺（N-酰胺加氨基氮或仅酰胺氮）和谷氨酸中，且未检测到游离铵离子。1.0 mM的谷氨酰胺合成酶抑制剂甲硫氨酸亚砜亚胺（MSO）完全抑制了氮的掺入。在存在0.5 mM谷氨酸合酶抑制剂重氮丝氨酸（AZA）的情况下，仅在谷氨酰胺的酰胺基团中检测到氮的掺入。结果证实了谷氨酰胺合成酶/谷氨酸合酶（GS/GOGAT）途径参与铵离子的同化过程。