Multiple forms of nitrate reductase and their role in nitrate assimilation in roots of wheat at low temperature or high salinity

1995 ◽  
Vol 93 (2) ◽  
pp. 249-252 ◽  
Author(s):  
Saule Kenjebaeva ◽  
Natasha Rakova
Keyword(s):  
Low Temperature ◽  
Nitrate Reductase ◽  
High Salinity ◽  
Nitrate Assimilation ◽  
Multiple Forms

scholarly journals Dephosphorylation of Nitrate Reductase Protein Regulates Growth of Rice and Adaptability to Low Temperature

2022 ◽  
Author(s):  
Ruicai Han ◽  
Chenyan Li ◽  
Huijie Li ◽  
Yupeng Wang ◽  
Xiaohua Pan ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nitrate Reductase ◽  
Chlorophyll Content ◽  
Phosphorylation Site ◽  
Nitrate Assimilation ◽  
Normal Growth ◽  
Growth Conditions ◽  
Nitrogen Utilization ◽  
Utilization Efficiency ◽  
Transgenic Lines

Abstract Nitrate reductase (NR) is an important enzyme for nitrate assimilation in plants, and its activity is regulated by post-translational phosphorylation. To investigate the effect of NIA1 protein dephosphorylation on the growth of rice and its adaptability to low temperature, we analyzed phenotype, chlorophyll content, nitrogen utilization, and antioxidant capacity at low temperature in lines with a mutated NIA1 phosphorylation site (S532D and S532A), an OsNia1 over-expression line (OE), and wild-type Kitaake rice (WT). Plant height, dry matter weight, and chlorophyll content of S532D and S532A were lower than those of WT and OE under normal growth conditions but were higher than those of WT and OE at low temperature. Compared with WT and OE, the nitrite, H2O2, and MDA contents of S532D and S532A leaves were higher under normal growth conditions. The difference in leaf nitrite content between transgenic lines and WT was narrower at low temperature, especially in S532D and S532A, while H2O2 and MDA contents of S532D and S532A leaves were lower than those in WT and OE leaves. The NH4+-N and amino acid contents of S532D and S532A leaves were higher than those of WT and OE leaves under normal or low temperature. qRT-PCR results revealed that transcription levels of OsNrt2.4, OsNia2, and OsNADH-GOGAT were positively correlated with those of OsNia1, and the transcription levels of OsNrt2.4, OsNia2, and OsNADH-GOGAT were significantly higher in transgenic lines than in WT under both normal and low temperature. Phosphorylation of NR is a steady-state regulatory mechanism of nitrogen metabolism, and dephosphorylation of NIA1 protein improved NR activity and nitrogen utilization efficiency in rice. Excessive accumulation of nitrite under normal growth conditions inhibits the growth of rice; however, accumulation of nitrite is reduced at low temperature, enhancing the cold tolerance of rice.

scholarly journals The Potential Roles of the G1LEA and G3LEA Proteins in Early Embryo Development and in Response to Low Temperature and High Salinity in Artemia sinica

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0162272 ◽  
Author(s):  
Wei Zhao ◽  
Feng Yao ◽  
Mengchen Zhang ◽  
Ting Jing ◽  
Shuang Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Embryo Development ◽  
High Salinity ◽  
Early Embryo ◽  
Artemia Sinica ◽  
Early Embryo Development

scholarly journals Low Temperature Illitization through Illite-Dioctahedral Vermiculite Mixed Layers in a Tropical Saline Lake Rich in Hydrothermal Fluids (Sochagota Lake, Colombia)

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 523
Author(s):  
Gabriel Ricardo Cifuentes ◽  
Juan Jiménez-Millán ◽  
Claudia Patricia Quevedo ◽  
Fernando Nieto ◽  
Javier Cuadros ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Low Temperature ◽  
High Salinity ◽  
Source Rocks ◽  
Temperate Climate ◽  
Lake Basin ◽  
X Ray ◽  
Saline Waters ◽  
Mixed Layers

In this investigation, we showed that high salinity promoted by hydrothermal inputs, reducing conditions of sediments with high content in organic matter, and the occurrence of an appropriate clay mineral precursor provide a suitable framework for low-temperature illitization processes. We studied the sedimentary illitization process that occurs in carbonaceous sediments from a lake with saline waters (Sochagota Lake, Colombia) located at a tropical latitude. Water isotopic composition suggests that high salinity was produced by hydrothermal contribution. Materials accumulated in the Sochagota Lake’s southern entrance are organic matter-poor sediments that contain detrital kaolinite and quartz. On the other hand, materials formed at the central segment and near the lake exit (north portion) are enriched in organic matter and characterized by the crystallization of Fe-sulfides. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectrometry (EDX) data allowed for the identification of illite and illite-dioctahedral vermiculite mixed layers (I-DV), which are absent in the southern sediments. High humidity and temperate climate caused the formation of small-sized metastable intermediates of I-DV particles by the weathering of the source rocks in the Sochagota Lake Basin. These particles were deposited in the low-energy lake environments (middle and north part). The interaction of these sediments enriched in organic matter with the saline waters of the lake enriched in hydrothermal K caused a reducing environment that favored Fe mobilization processes and its incorporation to I-DV mixed layers that acted as mineral precursor for fast low temperature illitization, revealing that in geothermal areas clays in lakes favor a hydrothermal K uptake.

Significance of nitrate reductase in nitrate assimilation in free-livingRhizobium cultures

1982 ◽  
Vol 38 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
M. H. Siddiqui ◽  
Anjali Mathur ◽  
S. N. Mathur
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Assimilation

scholarly journals Reticulate evolution in eukaryotes: origin and evolution of the nitrate assimilation pathway

2018 ◽  
Author(s):  
Eduard Ocaña-Pallarès ◽  
Sebastián R. Najle ◽  
Claudio Scazzocchio ◽  
Iñaki Ruiz-Trillo
Keyword(s):  
Nitrate Reductase ◽  
Gene Fusion ◽  
Evolutionary History ◽  
Transcriptional Control ◽  
Genetic Material ◽  
Nitrate Assimilation ◽  
Nitrogen Sources ◽  
Reticulate Evolution ◽  
Origin And Evolution ◽  
Ideal Object

AbstractGenes and genomes can evolve through interchanging genetic material, this leading to reticular evolutionary patterns. However, the importance of reticulate evolution in eukaryotes, and in particular of horizontal gene transfer (HGT), remains controversial. Given that metabolic pathways with taxonomically-patchy distributions can be indicative of HGT events, the eukaryotic nitrate assimilation pathway is an ideal object of investigation, as previous results revealed a patchy distribution and suggested one crucial HGT event. We studied the evolution of this pathway through both multi-scale bioinformatic and experimental approaches. Our taxon-rich genomic screening shows this pathway to be present in more lineages than previously proposed and that nitrate assimilation is restricted to autotrophs and to distinct osmotrophic groups. Our phylogenies show a pervasive role of HGT, with three bacterial transfers contributing to the pathway origin, and at least seven well-supported transfers between eukaryotes. Our results, based on a larger dataset, differ from the previously proposed transfer of a nitrate assimilation cluster from Oomycota (Stramenopiles) to Dikarya (Fungi, Opisthokonta). We propose a complex HGT path involving at least two cluster transfers between Stramenopiles and Opisthokonta. We also found that gene fusion played an essential role in this evolutionary history, underlying the origin of the canonical eukaryotic nitrate reductase, and of a novel nitrate reductase in Ichthyosporea (Opisthokonta). We show that the ichthyosporean pathway, including this novel nitrate reductase, is physiologically active and transcriptionally co-regulated, responding to different nitrogen sources; similarly to distant eukaryotes with independent HGT-acquisitions of the pathway. This indicates that this pattern of transcriptional control evolved convergently in eukaryotes, favoring the proper integration of the pathway in the metabolic landscape. Our results highlight the importance of reticulate evolution in eukaryotes, by showing the crucial contribution of HGT and gene fusion in the evolutionary history of the nitrate assimilation pathway.

scholarly journals Inactivation of gltB Abolishes Expression of the Assimilatory Nitrate Reductase Gene (nasB) in Pseudomonas putida KT2442

2000 ◽  
Vol 182 (12) ◽  
pp. 3368-3376 ◽  
Author(s):  
Leo Eberl ◽  
Aldo Ammendola ◽  
Michael H. Rothballer ◽  
Michael Givskov ◽  
Claus Sternberg ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Pseudomonas Putida ◽  
Nitrogen Starvation ◽  
Nitrate Assimilation ◽  
Glutamate Synthase ◽  
Nitrogen Sources ◽  
Nucleotide Sequence Analysis ◽  
Nitrate Reductase Gene ◽  
Physiological Characterization ◽  
Reductase Gene

ABSTRACT By using mini-Tn5 transposon mutagenesis, random transcriptional fusions of promoterless bacterial luciferase,luxAB, to genes of Pseudomonas putida KT2442 were generated. Insertion mutants that responded to ammonium deficiency by induction of bioluminescence were selected. The mutant that responded most strongly was genetically analyzed and is demonstrated to bear the transposon within the assimilatory nitrate reductase gene (nasB) of P. putida KT2442. Genetic evidence as well as sequence analyses of the DNA regions flanking nasBsuggest that the genes required for nitrate assimilation are not clustered. We isolated three second-site mutants in which induction ofnasB expression was completely abolished under nitrogen-limiting conditions. Nucleotide sequence analysis of the chromosomal junctions revealed that in all three mutants the secondary transposon had inserted at different sites in the gltB gene of P. putida KT2442 encoding the major subunit of the glutamate synthase. A detailed physiological characterization of thegltB mutants revealed that they are unable to utilize a number of potential nitrogen sources, are defective in the ability to express nitrogen starvation proteins, display an aberrant cell morphology under nitrogen-limiting conditions, and are impaired in the capacity to survive prolonged nitrogen starvation periods.

Rheology of Brine-Based Fuzzy-Ball Drilling Fluids in Deepwater Drilling

2019 ◽  
Author(s):  
Zhaochuan Li ◽  
Lihui Zheng ◽  
Panfeng Wei ◽  
Xiaojuan Dai ◽  
Weian Huang
Keyword(s):  
Low Temperature ◽  
Yield Point ◽  
Apparent Viscosity ◽  
High Salinity ◽  
Flow Behavior ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Working Fluid ◽  
Drilling Fluids ◽  
Deepwater Drilling

Abstract In deepwater drilling, the rheology of traditional drilling fluid is uncontrollable since the fluid usually mixes with brine and encounters low temperature. A solution may be to use the newly designed brine-based fuzzy-ball drilling fluids (BFDFs) since these have a well-adapted rheology under high salinity and low temperature condition. This has the potential to make drilling safer and more efficient. In this experiment, the rheological properties of BFDFs under test conditions were characterized with a rheometer by varying salinity (2 to 20 mass%) and temperature (4 to 80 °C). The rheological parameters considered are apparent viscosity (AV), plastic viscosity (PV), yield point (YP), and θ6 reading. To characterize the magnitudes of changes of the rheological parameters and their low temperature dependence, their ratios at 4 and 25 °C, and 4 and 80 °C were calculated. The results showed that the apparent viscosity (AV), the plastic viscosity (PV), the yield point (YP), and θ6 reading of BFDFs increased slightly with the decrease of salinity and temperature. The ratios of rheological parameters at 4 and 25 °C were close to unity, while the ratios at 4 and 80 °C were about two. The flow behavior of BFDFs under high salinity and low temperature condition was stable. Therefore, brine could be used as the base fluid for BFDFs. Theoretically, the flow behavior of BFDFs under low temperature condition seems to follow the Herschel-Bulkley model. Practically, the tests indicated that the BFDFs possess a strong tolerance to sandstone cuttings and Cabentonite, an excellent inhibitive property to shaly cuttings, weak corrosive characteristics against N80 casing steel, excellent lubricity properties, and remarkable biodegradability. In summary, the empirical results showed that the newly designed fuzzy-ball working fluid can use brine instead of fresh water as based fluid and maintain remarkable properties under high salinity and low temperature condition. Properties of BFDFs could basically satisfy the requirement of deepwater drilling work.

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