Influences of nitrogen deficiency on the transcript levels of ammonium transporter, nitrate transporter and glutamine synthetase genes in Isochrysis galbana (Isochrysidales, Haptophyta)

Phycologia ◽  
2007 ◽  
Vol 46 (5) ◽  
pp. 521-533 ◽  
Author(s):  
Lee-Kuo Kang ◽  
Sheng-Ping L. Hwang ◽  
Gwo-Ching Gong ◽  
Hsing-Juh Lin ◽  
Pei-Chung Chen ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Nitrogen Deficiency ◽  
Isochrysis Galbana ◽  
Ammonium Transporter ◽  
Nitrate Transporter ◽  
Transcript Levels

scholarly journals Integrative Transcriptomic and Proteomic Analysis Reveals an Alternative Molecular Network of Glutamine Synthetase 2 Corresponding to Nitrogen Deficiency in Rice (Oryza sativa L.)

2021 ◽  
Vol 22 (14) ◽  
pp. 7674
Author(s):  
Ting Liang ◽  
Zhengqing Yuan ◽  
Lu Fu ◽  
Menghan Zhu ◽  
Xiaoyun Luo ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Oryza Sativa L ◽  
Alternative Pathway ◽  
Rice Variety ◽  
Nitrogen Deficiency ◽  
Primary Root ◽  
Phenotypic Characterization ◽  
Glutathione Metabolism ◽  
N Assimilation ◽  
N Deficiency

Nitrogen (N) is an essential nutrient for plant growth and development. The root system architecture is a highly regulated morphological system, which is sensitive to the availability of nutrients, such as N. Phenotypic characterization of roots from LY9348 (a rice variety with high nitrogen use efficiency (NUE)) treated with 0.725 mM NH4NO3 (1/4N) was remarkable, especially primary root (PR) elongation, which was the highest. A comprehensive analysis was performed for transcriptome and proteome profiling of LY9348 roots between 1/4N and 2.9 mM NH4NO3 (1N) treatments. The results indicated 3908 differential expression genes (DEGs; 2569 upregulated and 1339 downregulated) and 411 differential abundance proteins (DAPs; 192 upregulated and 219 downregulated). Among all DAPs in the proteome, glutamine synthetase (GS2), a chloroplastic ammonium assimilation protein, was the most upregulated protein identified. The unexpected concentration of GS2 from the shoot to the root in the 1/4N treatment indicated that the presence of an alternative pathway of N assimilation regulated by GS2 in LY9348 corresponded to the low N signal, which was supported by GS enzyme activity and glutamine/glutamate (Gln/Glu) contents analysis. In addition, N transporters (NRT2.1, NRT2.2, NRT2.3, NRT2.4, NAR2.1, AMT1.3, AMT1.2, and putative AMT3.3) and N assimilators (NR2, GS1;1, GS1;2, GS1;3, NADH-GOGAT2, and AS2) were significantly induced during the long-term N-deficiency response at the transcription level (14 days). Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that phenylpropanoid biosynthesis and glutathione metabolism were significantly modulated by N deficiency. Notably, many transcription factors and plant hormones were found to participate in root morphological adaptation. In conclusion, our study provides valuable information to further understand the response of rice roots to N-deficiency stress.

scholarly journals Using Transcript Levels of Nitrate Transporter 2 as Molecular Indicators to Estimate the Potentials of Nitrate Transport in Symbiodinium, Cladocopium, and Durusdinium of the Fluted Giant Clam, Tridacna squamosa

2021 ◽  
Vol 8 ◽  
Author(s):  
Caryn Z. Pang ◽  
Yuen K. Ip ◽  
Shit F. Chew
Keyword(s):  
Nitrate Transport ◽  
Giant Clam ◽  
Nitrate Transporter ◽  
Bisphosphate Carboxylase ◽  
Transcript Levels ◽  
Carbon And Nitrogen ◽  
Enhanced Absorption ◽  
Symbiotic Dinoflagellates ◽  
Tridacna Squamosa ◽  
Molecular Indicators

Giant clams are important ecosystem engineers of coral reefs because they harbor large quantities of phototrophic Symbiodiniaceae dinoflagellates of mainly genera Symbiodinium, Cladocopium, and Durusdinium. The coccoid dinoflagellates donate photosynthate and amino acids to the clam host, which in return needs to supply inorganic carbon and nitrogen to them. The host can conduct light-enhanced absorption of nitrate (NO3–), which can only be metabolized by the symbionts. This study aimed to clone nitrate transporter 2 (NRT2) from the symbionts of the fluted giant clam, Tridacna squamosa. Here, we report three major sequences of NRT2 derived from Symbiodinium (Symb-NRT2), Cladocopium (Clad-NRT2) and Durusdinium (Duru-NRT2). Phenogramic analysis and molecular characterization confirmed that these three sequences were NRT2s derived from dinoflagellates. Immunofluorescence microscopy localized NRT2 at the plasma membrane and cytoplasmic vesicles of the symbiotic dinoflagellates, indicating that it could partake in the uptake and transport of NO3–. Therefore, the transcript levels of Symb-NRT2, Clad-NRT2, and Duru-NRT2 could be used as molecular indicators to estimate the potential of NO3– transport in five organs of 13 T. squamosa individuals. The transcript levels of form II ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcII) of Symbiodinium (Symb-rbcII), Cladocopium (Clad-rbcII) and Durusdinium (Duru-rbcII) were also determined in order to calculate the transcript ratios of Symb-NRT2/Symb-rbcII, Clad-NRT2/Clad-rbcII, and Duru-NRT2/Duru-rbcII. These ratios expressed the potentials of NO3– transport with reference to the phototrophic potentials in a certain genus of coccoid dinoflagellate independent of its quantity. Results obtained indicate that Symbiodinium generally had a higher potential of NO3– transport than Cladocopium and Durusdinium at the genus level. Furthermore, some phylotypes (species) of Symbiodinium, particularly those in the colorful outer mantle, had very high Symb-NRT2/Symb-rbcII ratio (7–13), indicating that they specialized in NO3– uptake and nitrogen metabolism. Overall, our results indicate for the first time that different phylotypes of Symbiodiniaceae dinoflagellates could have dissimilar abilities to absorb and assimilate NO3–, alluding to their functional diversity at the genus and species levels.

Effect of Nitrate on Activities and Transcript Levels of Nitrate Reductase and Glutamine Synthetase in Rice

Pedosphere ◽  
2008 ◽  
Vol 18 (5) ◽  
pp. 664-673 ◽  
Author(s):  
Yun CAO ◽  
Xiao-Rong FAN ◽  
Shu-Bin SUN ◽  
Guo-Hua XU ◽  
Jiang HU ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Glutamine Synthetase ◽  
Transcript Levels

scholarly journals The plant defensin gene AtPDF2.1 mediates ammonium metabolism by regulating glutamine synthetase activity in Arabidopsis thaliana

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Junyue Yao ◽  
Jin-Song Luo ◽  
Yan Xiao ◽  
Zhenhua Zhang
Keyword(s):  
Arabidopsis Thaliana ◽  
Glutamine Synthetase ◽  
Ammonium Transporter ◽  
Ammonium Concentration ◽  
Synthetase Activity ◽  
Vascular Bundles ◽  
Glutamine Synthetase Activity ◽  
Plant Defensin ◽  
Ammonium Metabolism ◽  
Localization Analysis

Abstract Background In plants, ammonium metabolism is particularly important for converting absorbed nitrogen into amino acids. However, the molecular mechanism underlying this conversion remains largely unknown. Results Using wild type Arabidopsis thaliana (Col-0) and AtPDF2.1 mutants (pdf2.1–1 and pdf2.1–2), we found that the small cysteine-rich peptide AtPDF2.1, a plant defensin, is involved in regulating ammonium metabolism in the shoot. Ammonium significantly induced the expression of AtPDF2.1 in the shoot and root, particularly in root xylem vascular bundles, as demonstrated by histochemical analysis. Subcellular localization analysis revealed that AtPDF2.1 was localized to the cell wall. Ammonium concentration was higher in the shoot of mutants than in the shoot of Col-0, but no differences were found for total nitrogen content, root ammonium concentration, and the expression of the ammonium transporter gene AtAMT2.1. The activity of glutamine synthetase was significantly decreased in mutants, and the glutamine synthetase family genes GLN1.3 and GLN1.5 were significantly downregulated in mutants compared to Col-0. The activity of nitrate reductase showed no difference between mutants and Col-0. Conclusions Overall, these data suggest that AtPDF2.1 affects ammonium metabolism by regulating the expression of GLN1.3 and GLN1.5 through a yet unidentified mechanism.

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