scholarly journals Drought, Salinity, and Low Nitrogen Differentially Affect the Growth and Nitrogen Metabolism of Sophora japonica (L.) in a Semi-Hydroponic Phenotyping Platform

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Tian ◽  
Yue Pang ◽  
Zhong Zhao
Keyword(s):  
Abiotic Stresses ◽  
N Uptake ◽  
Nutrient Deficiency ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Sophora Japonica ◽  
Affected Plant ◽  
Ammonium Transporters ◽  
Related Enzyme ◽  
N Metabolism

Abiotic stresses, such as salinity, drought, and nutrient deficiency adversely affect nitrogen (N) uptake and assimilation in plants. However, the regulation of N metabolism and N pathway genes in Sophora japonica under abiotic stresses is unclear. Sophora japonica seedlings were subjected to drought (5% polyethylene glycol 6,000), salinity (75mM NaCl), or low N (0.01mM NH4NO3) for 3weeks in a semi-hydroponic phenotyping platform. Salinity and low N negatively affected plant growth, while drought promoted root growth and inhibited aboveground growth. The NH4+/NO3− ratio increased under all three treatments with the exception of a reduction in leaves under salinity. Drought significantly increased leaf NO2− concentrations. Nitrate reductase (NR) activity was unaltered or increased under stresses with the exception of a reduction in leaves under salinity. Drought enhanced ammonium assimilation with increased glutamate synthase (GOGAT) activity, although glutamine synthetase (GS) activity remained unchanged, whereas salinity and low N inhibited ammonium assimilation with decreased GS activity under salt stress and decreased GOGAT activity under low N treatment. Glutamate dehydrogenase (GDH) activity also changed dramatically under different stresses. Additionally, expression changes of genes involved in N reduction and assimilation were generally consistent with related enzyme activities. In roots, ammonium transporters, especially SjAMT1.1 and SjAMT2.1a, showed higher transcription under all three stresses; however, most nitrate transporters (NRTs) were upregulated under salinity but unchanged under drought. SjNRT2.4, SjNRT2.5, and SjNRT3.1 were highly induced by low N. These results indicate that N uptake and metabolism processes respond differently to drought, salinity, and low N conditions in S. japonica seedlings, possibly playing key roles in plant resistance to environmental stress.

Expression of a ferredoxin-dependent glutamate synthase gene in mesophyll and vascular cells and functions of the enzyme in ammonium assimilation in Nicotiana tabacum (L.)

Planta ◽  
2005 ◽  
Vol 222 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Magali Feraud ◽  
Céline Masclaux-Daubresse ◽  
Sylvie Ferrario-Méry ◽  
Karine Pageau ◽  
Maud Lelandais ◽  
...  
Keyword(s):  
Nicotiana Tabacum ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Vascular Cells ◽  
Nicotiana Tabacum L

scholarly journals Ammonium Assimilation by Candida albicans and Other Yeasts: Evidence for Activity of Glutamate Synthase

Microbiology ◽  
1989 ◽  
Vol 135 (6) ◽  
pp. 1423-1430 ◽  
Author(s):  
A. R. HOLMES ◽  
A. COLLINGS ◽  
K. J. F. FARNDEN ◽  
M. G. SHEPHERD
Keyword(s):  
Candida Albicans ◽  
Glutamate Synthase ◽  
Ammonium Assimilation

scholarly journals Differential regulation of GS-GOGAT gene expression by plant growth regulators in Arabidopsis seedlings

2016 ◽  
Vol 68 (2) ◽  
pp. 399-404 ◽  
Author(s):  
Milan Dragicevic ◽  
Ana Simonovic ◽  
Milica Bogdanovic ◽  
Angelina Subotic ◽  
Nabil Ghalawenji ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Expression Patterns ◽  
Nuclear Gene ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
The Impact

Primary and secondary ammonium assimilation is catalyzed by the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway in plants. The Arabidopsis genome contains five cytosolic GS1 genes (GLN1;1 - GLN1;5), one nuclear gene for chloroplastic GS2 isoform (GLN2), two Fd-GOGAT genes (GLU1 and GLU2) and a GLT1 gene coding for NADH-GOGAT. Even though the regulation of GS and GOGAT isoforms has been extensively studied in response to various environmental and metabolic cues in many plant species, little is known about the effects of phytohormones on their regulation. The objective of this study was to investigate the impact of representative plant growth regulators, kinetin (KIN), abscisic acid (ABA), gibberellic acid (GA3) and 2,4-dichlorophenoxyacetic acid (2,4-D), on the expression of A. thaliana GS and GOGAT genes. The obtained results indicate that GS and GOGAT genes are differentially regulated by growth regulators in shoots and roots. KIN and 2,4-D repressed GS and GOGAT expression in roots, with little effect on transcript levels in shoots. KIN affected all tested genes; 2,4-D was apparently more selective and less potent. ABA induced the expression of GLN1;1 and GLU2 in whole seedlings, while GA3 enhanced the expression of all tested genes in shoots, except GLU2. The observed expression patterns are discussed in relation to physiological roles of investigated plant growth regulators and N-assimilating enzymes.

scholarly journals Autophagy mediates grain yield and nitrogen stress resistance by modulating nitrogen remobilization in rice

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244996
Author(s):  
Xiaoxi Zhen ◽  
Naimeng Zheng ◽  
Jinlei Yu ◽  
Congyuan Bi ◽  
Fan Xu
Keyword(s):  
Grain Yield ◽  
N Uptake ◽  
Utilization Efficiency ◽  
Autophagic Flux ◽  
Knock Out ◽  
Elevated Expression ◽  
Transgenic Lines ◽  
N Remobilization ◽  
N Metabolism ◽  
N Harvest Index

Autophagy, a conserved cellular process in eukaryotes, has evolved to a sophisticated process to dispose of intracellular constituents and plays important roles in plant development, metabolism, and efficient nutrients remobilization under suboptimal nutrients conditions. Here, we show that OsATG8b, an AUTOPHAGY-RELATED8 (ATG8) gene in rice, was highly induced by nitrogen (N) starvation. Elevated expression of OsATG8b significantly increased ATG8 lipidation, autophagic flux, and grain yield in rice under both sufficient and deficient N conditions. Overexpressing of OsATG8b could greatly increase the activities of enzymes related to N metabolism. Intriguingly, the 15N-labeling assay further revealed that more N was remobilized to seeds in OsATG8b-overexpressing rice, which significantly increased the N remobilization efficiency (NRE), N harvest index, N utilization efficiency (NUE), and N uptake efficiency (NUpE). Conversely, the osatg8b knock-out mutants had the opposite results on these characters. The substantial transcriptional changes of the overexpressed transgenic lines indicated the presence of complex signaling to developmental, metabolic process, and hormone, etc. Excitingly, the transgenic rice under different backgrounds all similarly be boosted in yield and NUE with OsATG8b overexpression. This work provides an excellent candidate gene for improving N remobilization, utilization, and yield in crops simultaneously.

scholarly journals Comparing and Contrasting the Multiple Roles of Butenolide Plant Growth Regulators: Strigolactones and Karrikins in Plant Development and Adaptation to Abiotic Stresses

2019 ◽  
Vol 20 (24) ◽  
pp. 6270 ◽  
Author(s):  
Tao Yang ◽  
Yuke Lian ◽  
Chongying Wang
Keyword(s):  
Plant Growth ◽  
Signaling Pathways ◽  
Plant Development ◽  
Abiotic Stresses ◽  
Growth And Development ◽  
Nutrient Deficiency ◽  
26S Proteasome ◽  
Plant Responses ◽  
Plant Growth And Development ◽  
Plant Matter

Strigolactones (SLs) and karrikins (KARs) are both butenolide molecules that play essential roles in plant growth and development. SLs are phytohormones, with SLs having known functions within the plant they are produced in, while KARs are found in smoke emitted from burning plant matter and affect seeds and seedlings in areas of wildfire. It has been suggested that SL and KAR signaling may share similar mechanisms. The α/β hydrolases DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2), which act as receptors of SL and KAR, respectively, both interact with the F-box protein MORE AXILLARY GROWTH 2 (MAX2) in order to target SUPPRESSOR OF MAX2 1 (SMAX1)-LIKE/D53 family members for degradation via the 26S proteasome. Recent reports suggest that SLs and/or KARs are also involved in regulating plant responses and adaptation to various abiotic stresses, particularly nutrient deficiency, drought, salinity, and chilling. There is also crosstalk with other hormone signaling pathways, including auxin, gibberellic acid (GA), abscisic acid (ABA), cytokinin (CK), and ethylene (ET), under normal and abiotic stress conditions. This review briefly covers the biosynthetic and signaling pathways of SLs and KARs, compares their functions in plant growth and development, and reviews the effects of any crosstalk between SLs or KARs and other plant hormones at various stages of plant development. We also focus on the distinct responses, adaptations, and regulatory mechanisms related to SLs and/or KARs in response to various abiotic stresses. The review closes with discussion on ways to gain additional insights into the SL and KAR pathways and the crosstalk between these related phytohormones.

Evaluating the Contribution of Glutamate Dehydrogenase and the Glutamate Synthase Cycle to Ammonia Assimilation by Four Ectomycorrhizal Fungal Isolates

1996 ◽  
Vol 23 (2) ◽  
pp. 151 ◽  
Author(s):  
MH Turnbull ◽  
R Goodall ◽  
GR Stewart
Keyword(s):  
Glutamate Dehydrogenase ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Major Product ◽  
Ammonia Assimilation ◽  
Gas Chromatography Mass Spectrometry ◽  
Methionine Sulfoximine ◽  
Fungal Isolates ◽  
Glutamine Synthesis ◽  
Fungal Tissue

Combined gas chromatography-mass spectrometry were used to evaluate the contributions of glutamate dehydrogenase (GDH) and the glutamate synthase cycle in 15N-labelled ammonium assimilation by four ectomycorrhizal fungal isolates. In all four species (Elaphomyces, Amanita, Pisolithus and Gautieria), glutamine was the major product accumulated following transfer of 14-day-old nitrogen-limited cultures to fresh medium. Label was rapidly assimilated into fungal tissue, with rates of 733 nmol g-1 FW h-1 in Pisolithus, 972 nmol g-1 FW h-1 in Amanita, 2760 nmol g-1 FW h-1 in Gautieria and 6756 nmol g-1 FW h-1 in Elaphomyces sp in the first 4 h of incubation. Incorporation of [15N]ammonium was sensitive to the inhibitory effects of both methionine sulfoximine (MSX, an inhibitor of glutamine synthetase (GS)) and albizziin (an inhibitor of glutamate synthase (GOGAT)) in three species (Amanita, Gautieria and Pisolithus) and labelling patterns were consistent with the action of the glutamate synthase cycle in ammonium assimilation. In all three species glutamine synthesis was almost totally blocked by MSX and there was no continued incorporation of 15N into glutamate. Elaphomyces displayed high levels of total incorporation of labelled ammonium in mycelium even in the presence of MSX, although incorporation into glutamine was reduced by 88%. This inhibition of GS by MSX, in addition to its partial inhibition by albizziin suggests strongly the action of glutamate synthase cycle in ammonium assimilation. The reduction in label entering glutamate under the influence of albizziin is direct evidence for the inhibition of GOGAT activity. However, MSX treatment had the effect of increasing significantly the quantity of label recovered in both glutamate and alanine. In the absence of GS inhibition there is clearly competition for ammonium which under normal physiological conditions results in assimilation through the glutamate synthase cycle. However, when GS is blocked by MSX label is able to cycle through the GDH pathway. Extra keywords: ectomycorrhiza, ammonium assimilation, glutamate synthase cycle, glutamate dehydrogenase, amino acid metabolism.

scholarly journals Molybdenum-Induced Effects on Nitrogen Metabolism Enzymes and Elemental Profile of Winter Wheat (Triticum aestivum L.) Under Different Nitrogen Sources

2019 ◽  
Vol 20 (12) ◽  
pp. 3009 ◽  
Author(s):  
Muhammad Imran ◽  
Xuecheng Sun ◽  
Saddam Hussain ◽  
Usman Ali ◽  
Muhammad Shoaib Rana ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Mineral Elements ◽  
Wheat Cultivars ◽  
N Sources ◽  
Metabolism Enzymes ◽  
Winter Wheat Cultivars ◽  
N Metabolism ◽  
Hydroponic Study

Different nitrogen (N) sources have been reported to significantly affect the activities and expressions of N metabolism enzymes and mineral elements concentrations in crop plants. However, molybdenum-induced effects in winter wheat cultivars have still not been investigated under different N sources. Here, a hydroponic study was carried out to investigate these effects on two winter wheat cultivars (‘97003’ and ‘97014’) as Mo-efficient and Mo-inefficient, respectively, under different N sources (NO3−, NH4NO3, and NH4+). The results revealed that the activities of nitrate reductase (NR) and nitrite reductase (NiR) followed the order of NH4NO3 > NO3− > NH4+ sources, while glutamine synthetase (GS) and glutamate synthase (GOGAT) followed the order of NH4+ > NH4NO3 > NO3− in both the wheat cultivars. However, Mo-induced effects in the activities and expressions of N metabolism enzymes under different N sources followed the order of NH4NO3 > NO3− > NH4+ sources, indicating that Mo has more complementary effects towards nitrate nutrition than the sole ammonium source in winter wheat. Interestingly, under −Mo-deprived conditions, cultivar ‘97003’ recorded more pronounced alterations in Mo-dependent parameters than ‘97014’ cultivar. Moreover, Mo application increased the proteins, amino acids, ammonium, and nitrite contents while concomitantly decreasing the nitrate contents in the same order of NH4NO3 > NO3− > NH4+ sources that coincides with the Mo-induced N enzymes activities and expressions. The findings of the present study indicated that Mo plays a key role in regulating the N metabolism enzymes and assimilatory products under all the three N sources; however, the extent of complementation exists in the order of NH4NO3 > NO3− > NH4+ sources in winter wheat. In addition, it was revealed that mineral elements profiles were mainly affected by different N sources, while Mo application generally had no significant effects on the mineral elements contents in the winter wheat leaves under different N sources.

Metabolic characterization of Acetobacter diazotrophicus

1995 ◽  
Vol 41 (10) ◽  
pp. 918-924 ◽  
Author(s):  
B. Alvarez ◽  
G. Martínez-Drets
Keyword(s):  
Nitrogen Metabolism ◽  
Respiratory Chain ◽  
Tricarboxylic Acid Cycle ◽  
Extracellular Enzyme ◽  
Glutamate Synthase ◽  
Ammonium Assimilation ◽  
Pentose Phosphate ◽  
Acetobacter Diazotrophicus ◽  
High Sugar Concentration ◽  
Uptake Studies

Carbon and nitrogen metabolism were investigated in Acetobacter diazotrophicus Pal 3, a N2-fixing bacterium able to grow at low pH and at high sugar concentration. Enzymatic, respiratory, and uptake studies were performed. The main active pathway for the catabolism of phosphorylated glucose was the pentose phosphate pathway. In addition, A. diazotrophicus directly oxidized glucose, gluconate, and ketogluconates through respiratory chain-linked enzymes. Soluble enzymes for the oxidation of glucose and gluconate were also found. Acetobacter diazotrophicus had a complete tricarboxylic acid cycle with a respiratory chain-linked malate dehydrogenase. The ability to grow on two- and three-carbon substrates would be explained by the presence of gluconeogenesis. Lack of bacterial growth on dicarboxylates was explained by the absence of a transport system. Ammonium assimilation proceeded mainly through glutamate dehydrogenase under ammonium excess but also through energy-demanding glutamine synthetase and glutamate synthase under N2-fixing conditions. Acetobacter diazotrophicus was not able to transport sucrose and its ability to grow on this disaccharide was explained by the presence of an extracellular enzyme with saccharolytic activity.Key words: Acetobacter diazotrophicus, carbon–nitrogen metabolism, extracellular saccharolytic activity, sucrose–succinate uptake.

scholarly journals Understanding and managing nitrogen nutrition in grapevine: a review

OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 1-43
Author(s):  
Thibaut Verdenal ◽  
Ágnes Dienes-Nagy ◽  
Jorge E. Spangenberg ◽  
Vivian Zufferey ◽  
Jean-Laurent Spring ◽  
...  
Keyword(s):  
Management Practices ◽  
Nitrogen Nutrition ◽  
N Uptake ◽  
Production Costs ◽  
Integrative Approach ◽  
Past Century ◽  
Wine Quality ◽  
N Nutrition ◽  
N Metabolism ◽  
N Status

This review addresses the role of nitrogen (N) in vine balance and grape composition. It offers an integrative approach to managing grapevine N nutrition. Keeping in mind that N excess is just as detrimental to wine quality as N depletion, the control of grapevine N status, and ultimately must N composition, is critical for high-quality grape production. N fertilisation has been intensively used in the past century, despite plants absorbing only 30 to 40 % of applied N. By adapting plant material, soil management and vine balance to environmental conditions, it would be possible for grape growers to improve plant N use efficiency and minimise N input in the vineyard. Vineyard N management is a complex exercise involving a search for a balance between controlling vigour, optimising grape composition, regulating production costs and limiting pollution. The first part of this review describes grapevine N metabolism from root N uptake to vine development and grape ripening, including the formation of grape aroma compounds. The advantages and limits of methods available for measuring plant N status are addressed. The second part focuses on the parameters that influence grapevine N metabolism, distinguishing the impacts of environmental factors from those of vineyard management practices. Areas for further research are also identified.

scholarly journals Sulfur Regulates the Trade-Off Between Growth and Andrographolide Accumulation via Nitrogen Metabolism in Andrographis paniculata

2021 ◽  
Vol 12 ◽  
Author(s):  
Shao-Fen Jian ◽  
Xue-Jing Huang ◽  
Xiao-Nan Yang ◽  
Chu Zhong ◽  
Jian-Hua Miao
Keyword(s):  
Plant Growth ◽  
Tca Cycle ◽  
Application Rate ◽  
Andrographis Paniculata ◽  
Trade Off ◽  
Carbohydrate Consumption ◽  
Affected Plant ◽  
N Assimilation ◽  
N Metabolism ◽  
S Application

Nitrogen (N) and sulfur (S) are essential mineral nutrients for plant growth and metabolism. Here, we investigated their interaction in plant growth and andrographolide accumulation in medicinal plant Andrographis paniculata grown at different N (4 and 8 mmol·L−1) and S concentration levels (0.1 and 2.4 mmol L−1). We found that increasing the S application rate enhanced the accumulation of andrographolide compounds (AGCs) in A. paniculata. Simultaneously, salicylic acid (SA) and gibberellic acid 4 (GA4) concentrations were increased but trehalose/trehalose 6-phosphate (Tre/Tre6P) concentrations were decreased by high S, suggesting that they were involved in the S-mediated accumulation of AGCs. However, S affected plant growth differentially at different N levels. Metabolite analysis revealed that high S induced increases in the tricarboxylic acid (TCA) cycle and photorespiration under low N conditions, which promoted N assimilation and S metabolism, and simultaneously increased carbohydrate consumption and inhibited plant growth. In contrast, high S reduced N and S concentrations in plants and promoted plant growth under high N conditions. Taken together, the results indicated that increasing the S application rate is an effective strategy to improve AGC accumulation in A. paniculata. Nevertheless, the interaction of N and S affected the trade-off between plant growth and AGC accumulation, in which N metabolism plays a key role.

Sign in / Sign up

Export Citation Format

Share Document