scholarly journals Effects of salinity on photosynthetic traits, ion homeostasis and nitrogen metabolism in wild and cultivated soybean

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8191 ◽  
Author(s):  
Abd Ullah ◽  
Mingxia Li ◽  
Javaria Noor ◽  
Akash Tariq ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Glutamate Dehydrogenase ◽  
Nitrogen Metabolism ◽  
Nitrogen Assimilation ◽  
Wild Soybean ◽  
Nitrate Assimilation ◽  
Saline Stress ◽  
Alkaline Stress ◽  
Ion Regulation ◽  
Cultivated Soybean ◽  
The Impact

Background Carbon and nitrogen metabolism need to be highly regulated to achieve cell acclimation to changing environmental conditions. The understanding of physio-biochemical responses of crops to salinity stress could help to stabilize their performance and yield. In this study we have analyzed the roles of photosynthesis, ion physiology and nitrate assimilation toward saline/alkaline stress acclimation in wild and cultivated soybean seedlings. Methods Growth and photosynthetic parameters, ion concentrations and the activity of enzymes involved in nitrogen assimilation were determined in seedlings of one wild and one cultivated soybean accession subjected to saline or alkaline stresses. Results Both saline and alkaline stresses had a negative impact on the growth and metabolism of both wild and cultivated soybean.The growth, photosynthesis, and gas exchange parameters showed a significant decrease in response to increasing salt concentration. Additionally, a significant increase in root Na+ and Cl– concentration was observed. However, photosynthetic performance and ion regulation were higher in wild than in cultivated soybean under saline and alkaline stresses. Nitrate reductase (NR) and the glutamine synthetase/glutamate synthase (GS/GOGAT) cycle showed a significant decrease in leaves of both genotypes. The reduction in the GS/GOGAT cycle was accompanied by high aminating glutamate dehydrogenase (NADH-glutamate dehydrogenase) activity, indicating the assimilation of high levels of NH4+. A significant increase in the activities of aminating and deaminating enzymes, including glutamate dehydrogenase (GDH), alanine aminotransferase (AlaAT) and aspartate aminotransferase (AspAT), was observed, probably due to the high glutamate demand and maintenance of the Krebs cycle to correct the C: N status. Conclusions Cultivated soybean was much more stress sensitive than was the wild soybean. The decrease in growth, photosynthesis, ion regulation and nitrogen assimilation enzymes was greater in cultivated soybean than in wild soybean. The impact of alkaline stress was more pronounced than that of saline stress. Wild soybean regulated the physiological mechanisms of photosynthesis and nitrate assimilation more effectively than did cultivated soybean. The present findings provide a theoretical basis with which to screen and utilize wild and cultivated soybean germplasm for breeding new stress-tolerant soybean.

Nitrogen metabolism and chloramphenicol production in Streptomyces venezuelae

1983 ◽  
Vol 29 (12) ◽  
pp. 1706-1714 ◽  
Author(s):  
S. Shapiro ◽  
L. C. Vining
Keyword(s):  
Growth Rate ◽  
Glutamate Dehydrogenase ◽  
Nitrogen Metabolism ◽  
Nitrogen Assimilation ◽  
Glutamate Synthase ◽  
Biomass Accumulation ◽  
Nitrogen Sources ◽  
Ph Control ◽  
Ammonium Nitrogen ◽  
Streptomyces Venezuelae

The relationship between chloramphenicol production and nitrogen metabolism in Streptomyces venezuelae was examined in stirred jar cultures under pH control. Nitrogen sources that supported rapid biomass accumulation gave low rates of antibiotic synthesis during growth. This was consistent with a general incompatibility between fast growth and high yields of chloramphenicol. In media where the growth rate was reduced below the attainable maximum by the rate at which nitrogen could be assimilated, chloramphenicol production was associated with biomass accumulation. Enzymes that are potentially associated with nitrogen assimilation pathways were assayed in cultures supplied with nitrogen sources supporting markedly different growth rates. The results indicated mat glutamine synthetase and alanine dehydrogenase levels were relatively insensitive to changes in growth rate and nitrogen source depletion. Glutamate dehydrogenase and glutamate synthase, on the other hand, showed high activity in cultures assimilating ammonium nitrogen and markedly decreased activity with poorer nitrogen sources or when ammonium was depleted. If chloramphenicol biosynthesis is coordinately controlled by mechanisms that regulate nitrogen assimilation, glutamate synthase and glutamate dehydrogenase are the most likely enzymes that manifest the regulatory linkage.

Glutamate synthase levels in Neurospora crassa mutants altered with respect to nitrogen metabolism

1981 ◽  
Vol 1 (2) ◽  
pp. 158-164
Author(s):  
N S Dunn-Coleman ◽  
E A Robey ◽  
A B Tomsett ◽  
R H Garrett
Keyword(s):  
Neurospora Crassa ◽  
Glutamate Dehydrogenase ◽  
Nitrogen Metabolism ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Glutamate Synthase ◽  
Wild Type ◽  
Mutant Strains ◽  
Synthase Regulation ◽  
Glutamate Biosynthesis ◽  
Glutamine Limitation

Glutamate synthase catalyzes glutamate formation from 2-oxoglutarate plus glutamine and plays an essential role when glutamate biosynthesis by glutamate dehydrogenase is not possible. Glutamate synthase activity has been determined in a number of Neurospora crassa mutant strains with various defects in nitrogen metabolism. Of particular interest were two mutants phenotypically mute except in an am (biosynthetic nicotinamide adenine dinucleotide phosphate-glutamate dehydrogenase deficient, glutamate requiring) background. These mutants, i and en-am, are so-called enhancers of am; they have been redesignated herein as en(am)-1 and en(am)-2, respectively. Although glutamate synthase levels in en(am)-1 were essentially wild type, the en(am)-2 strain was devoid of glutamate synthase activity under all conditions examined, suggesting that en(am)-2 may be the structural locus for glutamate synthase. Regulation of glutamate synthase occurred to some extent, presumably in response to glutamate requirements. Glutamate starvation, as in am mutants, led to enhanced activity. In contrast, glutamine limitation, as in gln-1 mutants, depressed glutamate synthase levels.

scholarly journals Role of Ureolytic Activity in Bacillus cereus Nitrogen Metabolism and Acid Survival

2008 ◽  
Vol 74 (8) ◽  
pp. 2370-2378 ◽  
Author(s):  
Maarten Mols ◽  
Tjakko Abee
Keyword(s):  
Bacillus Cereus ◽  
Nitrogen Source ◽  
Nitrogen Metabolism ◽  
Acid Stress ◽  
Main Role ◽  
Strain Atcc ◽  
Acid Shock ◽  
Acidic Conditions ◽  
The Impact

ABSTRACT The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including the sequenced strain ATCC 10987, could not use urea for growth, despite their capacities to produce active urease. These observations can be explained by the inability of the two strains to use ammonium as a nitrogen source. The impact of urea hydrolysis on acid stress resistance was subsequently assessed among the ureolytic B. cereus strains. However, none of the strains displayed increased fitness under acidic conditions or showed enhanced acid shock survival in the presence of urea. Expression analysis of urease genes in B. cereus ATCC 10987 revealed a low level of expression of these genes and a lack of pH-, nitrogen-, urea-, oxygen-, and growth phase-dependent modulation of mRNA transcription. This is in agreement with the low urease activity observed in strain ATCC 10987 and the other nine strains tested. Although a role for B. cereus ureolytic activity in acid survival cannot be excluded, its main role appears to be in nitrogen metabolism, where ammonium may be provided to the cells in nitrogen-limited, urea-containing environments.

scholarly journals Beneficial Effects of Biochar-Based Organic Fertilizer on Nitrogen Assimilation, Antioxidant Capacities, and Photosynthesis of Sugar Beet (Beta vulgaris L.) under Saline-Alkaline Stress

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1562
Author(s):  
Pengfei Zhang ◽  
Fangfang Yang ◽  
He Zhang ◽  
Lei Liu ◽  
Xinyu Liu ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Nitrogen Assimilation ◽  
Organic Fertilizer ◽  
Root Activity ◽  
Alkaline Stress ◽  
Alkaline Soil ◽  
Chemical Fertilizers ◽  
Alkaline Conditions ◽  
Negative Effect ◽  
Antioxidant Enzymes Activities

The Songnen Plain, whose climatic conditions are perfectly suited to sugar beet growth, is located in northeastern China. Unfortunately, this region has a lot of saline-alkaline land, which is the most important factor limiting sugar beet production. This study was undertaken to determine whether biochar-based organic fertilizer could alleviate the negative effect of saline-alkaline soil on sugar beet yield and whether such an effect correlated with changes in nitrogen assimilation, antioxidant system, root activity, and photosynthesis. Three treatments were established: Chemical fertilizers were applied to neutral soil (CK), chemical fertilizers were applied to saline-alkaline soil (SA), and biochar-based organic fertilizer was applied to saline-alkaline soil (SA + B). Our results showed that saline-alkaline stress significantly inhibited the nitrogen assimilation and antioxidant enzymes activities in root, root activity, and photosynthesis, thus significantly reducing the yield and sugar content of sugar beet. Under saline-alkaline conditions, the application of biochar-based organic fertilizer improved the activities of nitrogen assimilation enzymes in the root; at the same time, the antioxidant enzymes activities of the root were significantly increased for improving root activity in this treatment. Moreover, the application of biochar-based organic fertilizer could improve the synthesis of photosynthetic pigments, PSII (Photosystem II) activity, stomatal opening, and photosynthesis of sugar beet under saline-alkaline conditions. Hence, the growth and yield of sugar beet were improved by applying biochar-based organic fertilizer to saline-alkaline soil. These results proved the significance of biochar-based organic fertilizer in alleviating the negative effect of saline-alkaline stress on sugar beet. The results obtained in the pot experiment may not be viable in field conditions. Therefore, in the future, we will verify whether biochar-based organic fertilizer could alleviate the adverse effects of saline-alkaline stress on sugar beets yield under field conditions.

scholarly journals Genetic Control and Geo-Climate Adaptation of Pod Dehiscence Provide Novel Insights into Soybean Domestication

2019 ◽  
Vol 10 (2) ◽  
pp. 545-554 ◽  
Author(s):  
Jiaoping Zhang ◽  
Asheesh K. Singh
Keyword(s):  
Association Analysis ◽  
Climate Adaptation ◽  
Southern China ◽  
Glycine Soja ◽  
Wild Soybean ◽  
Candidate Gene Association ◽  
Genome Wide ◽  
Cultivated Soybean ◽  
Soybean Domestication ◽  
Pod Dehiscence

Loss of pod dehiscence was a key step in soybean [Glycine max (L.) Merr.] domestication. Genome-wide association analysis for soybean shattering identified loci harboring Pdh1, NST1A and SHAT1-5. Pairwise epistatic interactions were observed, and the dehiscent Pdh1 overcomes resistance conferred by NST1A or SHAT1-5 locus. Further candidate gene association analysis identified a nonsense mutation in NST1A associated with pod dehiscence. Geographic analysis showed that in Northeast China (NEC), indehiscence at both Pdh1 and NST1A were required in cultivated soybean, while indehiscent Pdh1 alone is capable of preventing shattering in Huang-Huai-Hai (HHH) valleys. Indehiscent Pdh1 allele was only identified in wild soybean (Glycine soja L.) accession from HHH valleys suggesting that it may have originated in this region. No specific indehiscence was required in Southern China. Geo-climatic investigation revealed strong correlation between relative humidity and frequency of indehiscent Pdh1 across China. This study demonstrates that epistatic interaction between Pdh1 and NST1A fulfills a pivotal role in determining the level of resistance against pod dehiscence, and humidity shapes the distribution of indehiscent alleles. Our results give further evidence to the hypothesis that HHH valleys was at least one of the origin centers of cultivated soybean.

Cellular and subcellular localisation of glutamine synthetase and glutamate dehydrogenase in grapes gives new insights on the regulation of carbon and nitrogen metabolism

Planta ◽  
2002 ◽  
Vol 216 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Virginie Paczek ◽  
Fréréric Dubois ◽  
Rajbir Sangwan ◽  
Jean-François Morot-Gaudry ◽  
Kalliopi Roubelakis-Angelakis ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Glutamate Dehydrogenase ◽  
Nitrogen Metabolism ◽  
Subcellular Localisation ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Metabolism

scholarly journals The sRNA NsiR4 is involved in nitrogen assimilation control in cyanobacteria by targeting glutamine synthetase inactivating factor IF7

2015 ◽  
Vol 112 (45) ◽  
pp. E6243-E6252 ◽  
Author(s):  
Stephan Klähn ◽  
Christoph Schaal ◽  
Jens Georg ◽  
Desirée Baumgartner ◽  
Gernot Knippen ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Nitrogen Metabolism ◽  
Nitrogen Assimilation ◽  
Nitrogen Sources ◽  
Transcriptome Profiling ◽  
Site Directed Mutagenesis ◽  
Reporter System ◽  
Available Nitrogen ◽  
Mrna Accumulation

Glutamine synthetase (GS), a key enzyme in biological nitrogen assimilation, is regulated in multiple ways in response to varying nitrogen sources and levels. Here we show a small regulatory RNA, NsiR4 (nitrogen stress-induced RNA 4), which plays an important role in the regulation of GS in cyanobacteria. NsiR4 expression in the unicellularSynechocystissp. PCC 6803 and in the filamentous, nitrogen-fixingAnabaenasp. PCC 7120 is stimulated through nitrogen limitation via NtcA, the global transcriptional regulator of genes involved in nitrogen metabolism. NsiR4 is widely conserved throughout the cyanobacterial phylum, suggesting a conserved function. In silico target prediction, transcriptome profiling on pulse overexpression, and site-directed mutagenesis experiments using a heterologous reporter system showed that NsiR4 interacts with the 5′UTR ofgifAmRNA, which encodes glutamine synthetase inactivating factor (IF)7. InSynechocystis, we observed an inverse relationship between the levels of NsiR4 and the accumulation of IF7 in vivo. This NsiR4-dependent modulation ofgifA(IF7) mRNA accumulation influenced the glutamine pool and thusNH4+assimilation via GS. As a second target, we identifiedssr1528, a hitherto uncharacterized nitrogen-regulated gene. Competition experiments between WT and an ΔnsiR4KO mutant showed that the lack of NsiR4 led to decreased acclimation capabilities ofSynechocystistoward oscillating nitrogen levels. These results suggest a role for NsiR4 in the regulation of nitrogen metabolism in cyanobacteria, especially for the adaptation to rapid changes in available nitrogen sources and concentrations. NsiR4 is, to our knowledge, the first identified bacterial sRNA regulating the primary assimilation of a macronutrient.

Sign in / Sign up

Export Citation Format

Share Document