scholarly journals 134Cs Uptake and Growth at Various Cs+ and K+ Levels in Arabidopsis AtKUP7 Mutants

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1525
Author(s):  
Marek Šustr ◽  
Tereza Doksanská ◽  
Barbora Doležalová ◽  
Aleš Soukup ◽  
Edita Tylová
Keyword(s):  
High Risk ◽  
Agricultural Production ◽  
The Other ◽  
Health It ◽  
Plant Tolerance ◽  
Wild Type ◽  
K Uptake ◽  
Growth Phenotype ◽  
Low K

Radiocaesium is a pollutant with a high risk for the environment, agricultural production, and human health. It is mobile in ecosystems and can be taken up by plants via potassium transporters. In this study, we focused on the role of potassium transporter AtKUP7 of the KT/HAK/KUP family in Cs+ and K+ uptake by plants and in plant tolerance to caesium toxicity. We detected that Arabidopsiskup7 mutant accumulates significantly lower amounts of 134Cs in the root (86%) and in the shoot (69%) compared to the wild-type. On the other hand ability of the mutant to grow on media with toxic (100 and 200 µM) concentrations of Cs+ was not changed; moreover its growth was not impaired on low K+. We further investigated another mutant line in AtKUP7 and found that the growth phenotype of the kup7 mutants in K+ deficient conditions is much milder than previously published. Also, their accumulation of K+ in shoots is hindered only by severe potassium shortage.

scholarly journals Prostacyclin-IP signaling and prostaglandin E2-EP2/EP4 signaling both mediate joint inflammation in mouse collagen-induced arthritis

2006 ◽  
Vol 203 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Tetsuya Honda ◽  
Eri Segi-Nishida ◽  
Yoshiki Miyachi ◽  
Shuh Narumiya
Keyword(s):  
Rheumatoid Arthritis ◽  
Synovial Fluid ◽  
Joint Inflammation ◽  
Synovial Fibroblasts ◽  
The Other ◽  
Receptor Subtype ◽  
Significant Suppression ◽  
Wild Type ◽  
Collagen Induced Arthritis

Prostaglandin (PG)I2 (prostacyclin [PGI]) and PGE2 are abundantly present in the synovial fluid of rheumatoid arthritis (RA) patients. Although the role of PGE2 in RA has been well studied, how much PGI2 contributes to RA is little known. To examine this issue, we backcrossed mice lacking the PGI receptor (IP) to the DBA/1J strain and subjected them to collagen-induced arthritis (CIA). IP-deficient (IP−/−) mice exhibited significant reduction in arthritic scores compared with wild-type (WT) mice, despite anti-collagen antibody production and complement activation similar to WT mice. IP−/− mice also showed significant reduction in contents of proinflammatory cytokines, such as interleukin (IL)-6 in arthritic paws. Consistently, the addition of an IP agonist to cultured synovial fibroblasts significantly enhanced IL-6 production and induced expression of other arthritis-related genes. On the other hand, loss or inhibition of each PGE receptor subtype alone did not affect elicitation of inflammation in CIA. However, a partial but significant suppression of CIA was achieved by the combined inhibition of EP2 and EP4. Our results show significant roles of both PGI2-IP and PGE2-EP2/EP4 signaling in the development of CIA, and suggest that inhibition of PGE2 synthesis alone may not be sufficient for suppression of RA symptoms.

scholarly journals Rpb7 Can Interact with RNA Polymerase II and Support Transcription during Some Stresses Independently of Rpb4

1999 ◽  
Vol 19 (4) ◽  
pp. 2672-2680 ◽  
Author(s):  
Ayelet Sheffer ◽  
Mazal Varon ◽  
Mordechai Choder
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Stress Conditions ◽  
Cold Sensitivity ◽  
Starvation Period ◽  
Wild Type ◽  
Pol Ii ◽  
Growth Phenotype ◽  
Mild Temperature

ABSTRACT Rpb4 and Rpb7 are two yeast RNA polymerase II (Pol II) subunits whose mechanistic roles have recently started to be deciphered. Although previous data suggest that Rpb7 can stably interact with Pol II only as a heterodimer with Rpb4, RPB7 is essential for viability, whereas RPB4 is essential only during some stress conditions. To resolve this discrepancy and to gain a better understanding of the mode of action of Rpb4, we took advantage of the inability of cells lacking RPB4 (rpb4Δ, containing Pol IIΔ4) to grow above 30°C and screened for genes whose overexpression could suppress this defect. We thus discovered that overexpression of RPB7 could suppress the inability ofrpb4Δ cells to grow at 34°C (a relatively mild temperature stress) but not at higher temperatures. Overexpression ofRPB7 could also partially suppress the cold sensitivity ofrpb4Δ strains and fully suppress their inability to survive a long starvation period (stationary phase). Notably, however, overexpression of RPB4 could not override the requirement for RPB7. Consistent with the growth phenotype, overexpression of RPB7 could suppress the transcriptional defect characteristic of rpb4Δ cells during the mild, but not during a more severe, heat shock. We also demonstrated, through two reciprocal coimmunoprecipitation experiments, a stable interaction of the overproduced Rpb7 with Pol IIΔ4. Nevertheless, fewer Rpb7 molecules interacted with Pol IIΔ4 than with wild-type Pol II. Thus, a major role of Rpb4 is to augment the interaction of Rpb7 with Pol II. We suggest that Pol IIΔ4 contains a small amount of Rpb7 that is sufficient to support transcription only under nonstress conditions. When RPB7 is overexpressed, more Rpb7 assembles with Pol IIΔ4, enough to permit appropriate transcription also under some stress conditions.

scholarly journals Glucomannan-Mediated Attachment of Rhizobium leguminosarum to Pea Root Hairs Is Required for Competitive Nodule Infection

2008 ◽  
Vol 190 (13) ◽  
pp. 4706-4715 ◽  
Author(s):  
Alan Williams ◽  
Adam Wilkinson ◽  
Martin Krehenbrink ◽  
Daniela M. Russo ◽  
Angeles Zorreguieta ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Rhizobium Leguminosarum ◽  
Root Hairs ◽  
The Other ◽  
Plant Interactions ◽  
Wild Type ◽  
Polysaccharide Synthesis ◽  
Surface Polysaccharides

ABSTRACT The Rhizobium leguminosarum biovar viciae genome contains several genes predicted to determine surface polysaccharides. Mutants predicted to affect the initial steps of polysaccharide synthesis were identified and characterized. In addition to the known cellulose (cel) and acidic exopolysaccharide (EPS) (pss) genes, we mutated three other loci; one of these loci (gmsA) determines glucomannan synthesis and one (gelA) determines a gel-forming polysaccharide, but the role of the other locus (an exoY-like gene) was not identified. Mutants were tested for attachment and biofilm formation in vitro and on root hairs; the mutant lacking the EPS was defective for both of these characteristics, but mutation of gelA or the exoY-like gene had no effect on either type of attachment. The cellulose (celA) mutant attached and formed normal biofilms in vitro, but it did not form a biofilm on root hairs, although attachment did occur. The cellulose-dependent biofilm on root hairs appears not to be critical for nodulation, because the celA mutant competed with the wild-type for nodule infection. The glucomannan (gmsA) mutant attached and formed normal biofilms in vitro, but it was defective for attachment and biofilm formation on root hairs. Although this mutant formed nodules on peas, it was very strongly outcompeted by the wild type in mixed inoculations, showing that glucomannan is critical for competitive nodulation. The polysaccharide synthesis genes around gmsA are highly conserved among other rhizobia and agrobacteria but are absent from closely related bacteria (such as Brucella spp.) that are not normally plant associated, suggesting that these genes may play a wide role in bacterium-plant interactions.

scholarly journals Companies Committed to Responsible AI: From Principles towards Implementation and Regulation?

2021 ◽  
Author(s):  
Paul B. de Laat
Keyword(s):  
High Risk ◽  
Web Search ◽  
Self Regulation ◽  
The Other ◽  
Governmental Regulation ◽  
Societal Actors ◽  
The Usa ◽  
The One ◽  
Applications Of Ai

AbstractThe term ‘responsible AI’ has been coined to denote AI that is fair and non-biased, transparent and explainable, secure and safe, privacy-proof, accountable, and to the benefit of mankind. Since 2016, a great many organizations have pledged allegiance to such principles. Amongst them are 24 AI companies that did so by posting a commitment of the kind on their website and/or by joining the ‘Partnership on AI’. By means of a comprehensive web search, two questions are addressed by this study: (1) Did the signatory companies actually try to implement these principles in practice, and if so, how? (2) What are their views on the role of other societal actors in steering AI towards the stated principles (the issue of regulation)? It is concluded that some three of the largest amongst them have carried out valuable steps towards implementation, in particular by developing and open sourcing new software tools. To them, charges of mere ‘ethics washing’ do not apply. Moreover, some 10 companies from both the USA and Europe have publicly endorsed the position that apart from self-regulation, AI is in urgent need of governmental regulation. They mostly advocate focussing regulation on high-risk applications of AI, a policy which to them represents the sensible middle course between laissez-faire on the one hand and outright bans on technologies on the other. The future shaping of standards, ethical codes, and laws as a result of these regulatory efforts remains, of course, to be determined.

scholarly journals Exploitation and Protection of Resources in Ecological Farms of a Subregion of Lublin Voivodeship

2017 ◽  
Vol 10 (2) ◽  
pp. 5-15
Author(s):  
Agnieszka Siedlecka
Keyword(s):  
Sustainable Development ◽  
Natural Environment ◽  
Agricultural Production ◽  
The Other ◽  
Environmental Resources ◽  
Research Results

AbstractSubject and purpose of work: The purpose of the study is to evaluate the utilisation of resources necessary for agricultural production as well as their protection in farms conducting ecological production. The deliberations undertaken in this paper focus on certified farms due to their specificity and character of their production, which is compatible with the principles of sustainable development. Materials and methods: The article uses the results of research from twenty ecological farms in the Chełm- Zamość subregion of Lublin Voivodeship. The deciding factor in selecting this region was the prominent role of agricultural production in this region when compared to the other ones in the voivodeship. Results: The research results have shown that there is a lack of correlation between actions taken by producers and caring for the natural environment. Farmers displayed little awareness with regard to the use of environmental resources and assets in agricultural production. Conclusions: Running a farm aimed at ecological production is connected with the implementation of solutions that have not found application in traditional agricultural production, with obtaining a certificate and the need for training and further study. This does not, however, translate into the introduction of pro-ecological solutions in agricultural production or the farm itself. A significant share of the investigated producers did not report the need for introducing such solutions. It indicates the need for continuous broadening of knowledge and creating ecological.

Comparison of full-length and conserved segments of wheat dehydrin DHN-5 overexpressed in Arabidopsis thaliana showed different responses to abiotic and biotic stress

2016 ◽  
Vol 43 (11) ◽  
pp. 1048 ◽  
Author(s):  
Marwa Drira ◽  
Moez Hanin ◽  
Khaled Masmoudi ◽  
Faiçal Brini
Keyword(s):  
Arabidopsis Thaliana ◽  
Fungal Infections ◽  
Alternaria Solani ◽  
Triticum Aestivum L ◽  
Full Length ◽  
Plant Tolerance ◽  
Wild Type ◽  
Biotic And Abiotic Stresses ◽  
Related Stress

Dehydrins (DHNs) are among the most common proteins accumulated in plants under water-related stress. They typically contain at least three conserved sequences designated as the Y-, S- and K-segments. The present work aims to highlight the role of the K-segments in plant tolerance to biotic and abiotic stresses. For this purpose, transgenic Arabidopsis thaliana (L.) Heyhn. lines expressing distinct wheat (Triticum aestivum L.) DHN-5 truncated constructs with or without the K-segments were generated. Our results showed that unlike the derivative lacking a K-segment, constructs containing only one or two K-segments enhanced the tolerance of A. thaliana to diverse stresses and were similar to the full-length wheat DHN-5. Moreover, compared with the wild-type and the YS form, the transgenic plants overexpressing wheat DHN-5 with K-segments maintained higher superoxide dismutase, catalase and peroxide dismutase enzymatic activity, and accumulated lower levels of H2O2 and malondialdehyde. In addition, we demonstrated that lines like A. thaliana overexpressing wheat DHN-5 showed increased resistance to fungal infections caused by Botrytis cinerea and Alternaria solani. Finally, the overexpression of the different forms of wheat DHN-5 led to the regulation of the expression of several genes involved in the jasmonic acid signalling pathway.

scholarly journals Construction and Characterization of a Derivative of Neisseria gonorrhoeae Strain MS11 Devoid of AllopaGenes

2012 ◽  
Vol 194 (23) ◽  
pp. 6468-6478 ◽  
Author(s):  
Adriana LeVan ◽  
Lindsey I. Zimmerman ◽  
Amanda C. Mahle ◽  
Karen V. Swanson ◽  
Philip DeShong ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
The Other ◽  
Flow Cytometry Analysis ◽  
Wild Type ◽  
Homogeneous Population ◽  
Host Cell Interactions ◽  
Strain Ms11 ◽  
Adherence Ability

ABSTRACTTo better understand the role of Opa in gonococcal infections, we created and characterized a derivative of MS11 (MS11Δopa) that had the coding sequence for all 11 Opa proteins deleted. The MS11Δopa bacterium lost the ability to bind to purified lipooligosaccharide (LOS). While nonpiliated MS11Δopa and nonpiliated Opa-expressing MS11 cells grew at the same rate, nonpiliated MS11Δopa cells rarely formed clumps of more than four bacteria when grown in broth with vigorous shaking. Using flow cytometry analysis, we demonstrated that MS11Δopa produced a homogeneous population of bacteria that failed to bind monoclonal antibody (MAb) 4B12, a MAb specific for Opa. Opa-expressing MS11 cells consisted of two predominant populations, where ∼85% bound MAb 4B12 to a significant level and the other population bound little if any MAb. Approximately 90% of bacteria isolated from a phenotypically Opa-negative colony (a colony that does not refract light) failed to bind MAb 4B12; the remaining 10% bound MAb to various degrees. Piliated MS11Δopa cells formed dispersed microcolonies on ME180 cells which were visually distinct from those of piliated Opa-expressing MS11 cells. When Opa expression was reintroduced into MS11Δopa, the adherence ability of the strain recovered to wild-type levels. These data indicate that Opa contributes to both bacterium-bacterium and bacterium-host cell interactions.

scholarly journals SarA Is a Repressor of hla (α-Hemolysin) Transcription in Staphylococcus aureus: Its Apparent Role as an Activator of hla in the Prototype Strain NCTC 8325 Depends on Reduced Expression of sarS

2006 ◽  
Vol 188 (24) ◽  
pp. 8526-8533 ◽  
Author(s):  
Jan Oscarsson ◽  
Anna Kanth ◽  
Karin Tegmark-Wisell ◽  
Staffan Arvidson
Keyword(s):  
Staphylococcus Aureus ◽  
Northern Blot Analysis ◽  
Prototype Strain ◽  
Relative Increase ◽  
The Other ◽  
Wild Type ◽  
Triple Mutant ◽  
Strain Nctc ◽  
Repressor Activity

ABSTRACT In most Staphylococcus aureus strains, inactivation of sarA increases hla transcription, indicating that sarA is a repressor. However, in S. aureus NCTC 8325 and its derivatives, used for most studies of hla regulation, inactivation of sarA resulted in decreased hla transcription. The disparate phenotype of strain NCTC 8325 seems to be associated with its rsbU mutation, which leads to σB deficiency. This has now been verified by the demonstration that sarA repressed hla transcription in an rsbU + derivative of strain 8325-4 (SH1000). That sarA could act as a repressor of hla in an 8325-4 background was confirmed by the observation that inactivation of sarA in an agr sarS rot triple mutant dramatically increased hla transcription to wild-type levels. However, the apparent role of sarA as an activator of hla in 8325-4 was not a result of the rsbU mutation alone, as inactivation of sarA in another rsbU mutant, strain V8, led to increased hla transcription. Northern blot analysis revealed much higher levels of sarS mRNA in strain V8 than in 8325-4, which was likely due to the mutation in the sarS activator, tcaR, in 8325-4, which was not found in strain V8. On the other hand, the relative increase in sarS transcription upon the inactivation of sarA was 15-fold higher in 8325-4 than in strain V8. Because of this, inactivation of sarA in 8325-4 means a net increase in repressor activity, whereas in strain V8, inactivation of sarA means a net decrease in repressor activity and, therefore, enhanced hla transcription.

scholarly journals Analysis of behavioral variables across domains and skin phenotypes in zebrafish: Role of brain monoamines

2016 ◽  
Author(s):  
Monica Gomes Lima ◽  
Anderson Manoel Herculano ◽  
Caio Maximino
Keyword(s):  
The Other ◽  
The Novel ◽  
Wild Type ◽  
Behavioral Differences ◽  
Brain Monoamines ◽  
Novel Object ◽  
General Arousal ◽  
Behavioral Variables ◽  
Cross Test

AbstractImportant neurochemical variations between strains or linages which correlate with behavioral differences have been identified in different species. Here, we report neurochemical and behavioral differences in four common zebrafish wild-type phenotypes (blue shortfin, longfin stripped, leopard and albino). Leopad zebrafish have been shown to display increased scototaxis in relation to the other strains, while both albino and leopard zebrafish show increased geotaxis. Moreover, leopard displayed increased nocifensive behavior, while albino zebrafish showed increased neophobia in the novel object task. Longfin zebrafish showed decreased turn frequency in both the novel tank and light/dark tests, and habituated faster in the novel tank, as well as displaying increased 5-HT levels. Leopard zebrafish showed decreased brain 5-HT levels and increased 5-HT turnover than other strains, and albino had increased brain DA levels. Finally, specific behavioral endpoints co-varied in terms of the behavioral and neurochemical differences between strains, identifying cross-test domains which included response to novelty, exploration-avoidance, general arousal, and activity.

scholarly journals STOP1 Regulates LKS1 Transcription and Coordinates K+/NH4+ Balance in Arabidopsis Response to Low-K+ Stress

2021 ◽  
Vol 23 (1) ◽  
pp. 383
Author(s):  
Zhi-Fang Wang ◽  
Ting-Wei Mi ◽  
Yong-Qiang Gao ◽  
Han-Qian Feng ◽  
Wei-Hua Wu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Growth And Development ◽  
Transcript Level ◽  
Mineral Elements ◽  
The Other ◽  
Plant Growth And Development ◽  
K Uptake ◽  
Arabidopsis Root ◽  
Leaf Chlorosis ◽  
Low K

Potassium and nitrogen are essential mineral elements for plant growth and development. The protein kinase LKS1/CIPK23 is involved in both K+ and NH4+ uptake in Arabidopsis root. The transcripts of LKS1 can be induced by low K+ (0.1 mM) and high NH4+ (30 mM); however, the molecular mechanism is still unknown. In this study, we isolated the transcription factor STOP1 that positively regulates LKS1 transcription in Arabidopsis responses to both low-K+ and high-NH4+ stresses. STOP1 proteins can directly bind to the LKS1 promoter, promoting its transcription. The stop1 mutants displayed a leaf chlorosis phenotype similar to lks1 mutant when grown on low-K+ and high-NH4+ medium. On the other hand, STOP1 overexpressing plants exhibited a similar tolerant phenotype to LKS1 overexpressing plants. The transcript level of STOP1 was only upregulated by low K+ rather than high NH4+; however, the accumulation of STOP1 protein in the nucleus was required for the upregulation of LKS1 transcripts in both low-K+ and high-NH4+ responses. Our data demonstrate that STOP1 positively regulates LKS1 transcription under low-K+ and high-NH4+ conditions; therefore, LKS1 promotes K+ uptake and inhibits NH4+ uptake. The STOP1/LKS1 pathway plays crucial roles in K+ and NH4+ homeostasis, which coordinates potassium and nitrogen balance in plants in response to external fluctuating nutrient levels.

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