scholarly journals A bacterial assay for rapid screening of IAA catabolic enzymes

Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Federica Brunoni ◽  
Silvio Collani ◽  
Jan Šimura ◽  
Markus Schmid ◽  
Catherine Bellini ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Recombinant Protein ◽  
Recombinant Proteins ◽  
Transport Processes ◽  
Rapid Screening ◽  
In Vitro Assays ◽  
Supernatant Fraction ◽  
Activity Measurements ◽  
Glucosyl Ester

Abstract Background Plants rely on concentration gradients of the native auxin, indole-3-acetic acid (IAA), to modulate plant growth and development. Both metabolic and transport processes participate in the dynamic regulation of IAA homeostasis. Free IAA levels can be reduced by inactivation mechanisms, such as conjugation and degradation. IAA can be conjugated via ester linkage to glucose, or via amide linkage to amino acids, and degraded via oxidation. Members of the UDP glucosyl transferase (UGT) family catalyze the conversion of IAA to indole-3-acetyl-1-glucosyl ester (IAGlc); by contrast, IAA is irreversibly converted to indole-3-acetyl-l-aspartic acid (IAAsp) and indole-3-acetyl glutamic acid (IAGlu) by Group II of the GRETCHEN HAGEN3 (GH3) family of acyl amido synthetases. Dioxygenase for auxin oxidation (DAO) irreversibly oxidizes IAA to oxindole-3-acetic acid (oxIAA) and, in turn, oxIAA can be further glucosylated to oxindole-3-acetyl-1-glucosyl ester (oxIAGlc) by UGTs. These metabolic pathways have been identified based on mutant analyses, in vitro activity measurements, and in planta feeding assays. In vitro assays for studying protein activity are based on producing Arabidopsis enzymes in a recombinant form in bacteria or yeast followed by recombinant protein purification. However, the need to extract and purify the recombinant proteins represents a major obstacle when performing in vitro assays. Results In this work we report a rapid, reproducible and cheap method to screen the enzymatic activity of recombinant proteins that are known to inactivate IAA. The enzymatic reactions are carried out directly in bacteria that produce the recombinant protein. The enzymatic products can be measured by direct injection of a small supernatant fraction from the bacterial culture on ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UHPLC–ESI-MS/MS). Experimental procedures were optimized for testing the activity of different classes of IAA-modifying enzymes without the need to purify recombinant protein. Conclusions This new method represents an alternative to existing in vitro assays. It can be applied to the analysis of IAA metabolites that are produced upon supplementation of substrate to engineered bacterial cultures and can be used for a rapid screening of orthologous candidate genes from non-model species.

scholarly journals A bacterial assay for rapid screening of IAA catabolic enzymes

2019 ◽  
Author(s):  
Brunoni Federica ◽  
Collani Silvio ◽  
Šimura Jan ◽  
Schmid Markus ◽  
Bellini Catherine ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Recombinant Protein ◽  
Recombinant Proteins ◽  
Transport Processes ◽  
Rapid Screening ◽  
Supernatant Fraction ◽  
Enzymatic Reactions ◽  
Activity Measurements ◽  
Glucosyl Ester

AbstractBackgroundPlants rely on concentration gradients of the native auxin, indole-3-acetic acid (IAA), to modulate plant growth and development. Both metabolic and transport processes participate in the dynamic regulation of IAA homeostasis. Free IAA levels can be reduced by inactivation mechanisms, such as conjugation and degradation. IAA can be conjugated via ester linkage to glucose, or via amide linkage to amino acids, and degraded via oxidation. Members of the UDP glucosyl transferase (UGT) family catalyze the conversion of IAA to indole-3-acetyl-1-glucosyl ester (IAGlc); by contrast, IAA is irreversibly converted to indole-3-acetyl-L-aspartic acid (IAAsp) and indole-3-acetyl glutamic acid (IAGlu) by Group II of the GRETCHEN HAGEN3 (GH3) family of acyl amido synthetases. DIOXYGENASE OF AUXIN OXIDATION (DAO) irreversibly oxidizes IAA to oxindole-3-acetic acid (oxIAA) and, in turn, oxIAA can be further glucosylated to oxindole-3-acetyl-1-glucosyl ester (oxIAGlc) by UGTs. These metabolic pathways have been identified based on mutant analyses, in vitro activity measurements, and in planta feeding assays. In vitro assays for studying protein activity are based on expressing Arabidopsis enzymes in a recombinant form in bacteria or yeast followed by recombinant protein purification. However, the need to extract and purify the recombinant proteins represents a major obstacle when performing in vitro assays.ResultsIn this work we report a rapid, reproducible and cheap method to screen the enzymatic activity of recombinant proteins that are known to inactivate IAA. The enzymatic reactions are carried out directly in bacteria that express the recombinant protein. The enzymatic products can be measured by direct injection of a small supernatant fraction from the bacterial culture on ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UHPLC-ESI-MS/MS). Experimental procedures were optimized for testing the activity of different classes of IAA-modifying enzymes without the need to purify recombinant protein.ConclusionsThis new method represents an alternative to existing in vitro assays. It can be applied to the analysis of IAA metabolites that are produced upon supplementation of substrate to engineered bacterial cultures and can be used for a rapid screening of orthologous candidate genes from non-model species.

scholarly journals Characterization of Plant Growth-Promoting Traits and Inoculation Effects on Triticum durum of Actinomycetes Isolates under Salt Stress Conditions

Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Rihab Djebaili ◽  
Marika Pellegrini ◽  
Massimiliano Rossi ◽  
Cinzia Forni ◽  
Maria Smati ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Salt Stress ◽  
Plant Growth ◽  
Durum Wheat ◽  
Growth And Development ◽  
Indole Acetic Acid ◽  
Greenhouse Experiment ◽  
Hydrocyanic Acid ◽  
In Vitro Assays

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.

scholarly journals Tobacco Mosaic Virus Movement Protein Functions as a Structural Microtubule-Associated Protein

2006 ◽  
Vol 80 (17) ◽  
pp. 8329-8344 ◽  
Author(s):  
Jamie Ashby ◽  
Emmanuel Boutant ◽  
Mark Seemanpillai ◽  
Adrian Sambade ◽  
Christophe Ritzenthaler ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Extract ◽  
Transport Processes ◽  
In Vitro Assays ◽  
Protein Functions ◽  
Intercellular Spread

ABSTRACT The cell-to-cell spread of Tobacco mosaic virus infection depends on virus-encoded movement protein (MP), which is believed to form a ribonucleoprotein complex with viral RNA (vRNA) and to participate in the intercellular spread of infectious particles through plasmodesmata. Previous studies in our laboratory have provided evidence that the vRNA movement process is correlated with the ability of the MP to interact with microtubules, although the exact role of this interaction during infection is not known. Here, we have used a variety of in vivo and in vitro assays to determine that the MP functions as a genuine microtubule-associated protein that binds microtubules directly and modulates microtubule stability. We demonstrate that, unlike MP in whole-cell extract, microtubule-associated MP is not ubiquitinated, which strongly argues against the hypothesis that microtubules target the MP for degradation. In addition, we found that MP interferes with kinesin motor activity in vitro, suggesting that microtubule-associated MP may interfere with kinesin-driven transport processes during infection.

Biological activity of the non-microbial fraction of kefir: antagonism against intestinal pathogens

2017 ◽  
Vol 84 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Carolina Iraporda ◽  
Mário Abatemarco Júnior ◽  
Elisabeth Neumann ◽  
Álvaro Cantini Nunes ◽  
Jacques R Nicoli ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Biological Activity ◽  
Cell Model ◽  
Acetic Acid Bacteria ◽  
Fermented Milk ◽  
In Vitro Assays ◽  
Intestinal Epithelial ◽  
Milk Fermentation ◽  
Intestinal Pathogens

Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism againstEscherichia coli,Salmonellaspp. andBacillus cereus.During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion ofSalmonellawhereas pre-incubation ofSalmonellawith this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect againstSalmonellain a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.

Populus euphratica remorin 6.5 activates plasma membrane H+-ATPases to mediate salt tolerance

2020 ◽  
Vol 40 (6) ◽  
pp. 731-745
Author(s):  
Huilong Zhang ◽  
Chen Deng ◽  
Xia Wu ◽  
Jun Yao ◽  
Yanli Zhang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Salt Tolerance ◽  
Transgenic Plants ◽  
Recombinant Protein ◽  
Atpase Activity ◽  
Populus Euphratica ◽  
Hydrolytic Activity ◽  
In Vitro Assays

Abstract Remorins (REMs) play an important role in the ability of plants to adapt to adverse environments. PeREM6.5, a protein of the REM family in Populus euphratica (salt-resistant poplar), was induced by NaCl stress in callus, roots and leaves. We cloned the full-length PeREM6.5 from P. euphratica and transformed it into Escherichia coli and Arabidopsis thaliana. PeREM6.5 recombinant protein significantly increased the H+-ATPase hydrolytic activity and H+ transport activity in P. euphratica plasma membrane (PM) vesicles. Yeast two-hybrid assay showed that P. euphratica REM6.5 interacted with RPM1-interacting protein 4 (PeRIN4). Notably, the PeREM6.5-induced increase in PM H+-ATPase activity was enhanced by PeRIN4 recombinant protein. Overexpression of PeREM6.5 in Arabidopsis significantly improved salt tolerance in transgenic plants in terms of survival rate, root growth, electrolyte leakage and malondialdehyde content. Arabidopsis plants overexpressing PeREM6.5 retained high PM H+-ATPase activity in both in vivo and in vitro assays. PeREM6.5-transgenic plants had reduced accumulation of Na+ due to the Na+ extrusion promoted by the H+-ATPases. Moreover, the H+ pumps caused hyperpolarization of the PM, which reduced the K+ loss mediated by the depolarization-activated channels in the PM of salinized roots. Therefore, we conclude that PeREM6.5 regulated H+-ATPase activity in the PM, thus enhancing the plant capacity to maintain ionic homeostasis under salinity.

scholarly journals New Insights into Structural and Functional Roles of Indole-3-acetic acid (IAA): Changes in DNA Topology and Gene Expression in Bacteria

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 522 ◽  
Author(s):  
Defez ◽  
Valenti ◽  
Andreozzi ◽  
Romano ◽  
Ciaramella ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acetic Acid ◽  
Conformational Changes ◽  
Regulation Of Gene Expression ◽  
Dna Supercoiling ◽  
Dna Topology ◽  
In Vitro Assays ◽  
Bacterial Cells ◽  
Indole 3 Acetic Acid

: Indole-3-acetic acid (IAA) is a major plant hormone that affects many cellular processes in plants, bacteria, yeast, and human cells through still unknown mechanisms. In this study, we demonstrated that the IAA-treatment of two unrelated bacteria, the Ensifer meliloti 1021 and Escherichia coli, harboring two different host range plasmids, influences the supercoiled state of the two plasmid DNAs in vivo. Results obtained from in vitro assays show that IAA interacts with DNA, leading to DNA conformational changes commonly induced by intercalating agents. We provide evidence that IAA inhibits the activity of the type IA topoisomerase, which regulates the DNA topological state in bacteria, through the relaxation of the negative supercoiled DNA. In addition, we demonstrate that the treatment of E. meliloti cells with IAA induces the expression of some genes, including the ones related to nitrogen fixation. In contrast, these genes were significantly repressed by the treatment with novobiocin, which reduces the DNA supercoiling in bacterial cells. Taking into account the overall results reported, we hypothesize that the IAA action and the DNA structure/function might be correlated and involved in the regulation of gene expression. This work points out that checking whether IAA influences the DNA topology under physiological conditions could be a useful strategy to clarify the mechanism of action of this hormone, not only in plants but also in other unrelated organisms.

A in Vivo Assay for Standardizing Heparin Preparations

1979 ◽  
Vol 41 (03) ◽  
pp. 576-582
Author(s):  
A R Pomeroy
Keyword(s):  
In Vitro Assays ◽  
British Pharmacopoeia ◽  
In Vitro Method ◽  
Standard Preparation ◽  
Reliable Estimation ◽  
Assay Procedure ◽  
Accuracy And Precision ◽  
Heparin Preparation

SummaryThe limitations of currently used in vitro assays of heparin have demonstrated the need for an in vivo method suitable for routine use.The in vivo method which is described in this paper uses, for each heparin preparation, four groups of five mice which are injected intravenously with heparin according to a “2 and 2 dose assay” procedure. The method is relatively rapid, requiring 3 to 4 hours to test five heparin preparations against a standard preparation of heparin. Levels of accuracy and precision acceptable for the requirements of the British Pharmacopoeia are obtained by combining the results of 3 to 4 assays of a heparin preparation.The similarity of results obtained the in vivo method and the in vitro method of the British Pharmacopoeia for heparin preparations of lung and mucosal origin validates this in vivo method and, conversely, demonstrates that the in vitro method of the British Pharmacopoeia gives a reliable estimation of the in vivo activity of heparin.

Potentially Thrombogenic Materials in Factor IX Concentrates

1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson
Keyword(s):  
Human Plasma ◽  
Antithrombin Iii ◽  
Factor Ix ◽  
In Vitro Assays ◽  
Substantial Agreement ◽  
Coefficient Of Correlation

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.

Callus Induction and Plant Regeneration in Rauvolfia Serpentina (L.) Benth Ex. Kurz.

2009 ◽  
Vol 24 ◽  
pp. 82-88 ◽  
Author(s):  
Saraswoti Aryal ◽  
Sanu Devi Joshi
Keyword(s):  
Acetic Acid ◽  
Callus Induction ◽  
Coconut Milk ◽  
Ms Medium ◽  
Rauvolfia Serpentina ◽  
History Museum ◽  
Short Period ◽  
Murashige Skoog ◽  
Callus Tissue Culture

Rauvolfia serpentina (L.) ex. Kurz is an important medicinal plant. Callus induction and regeneration was studied from stem explant of in-vitro grown plant of Rauvolfia serpentina(L.) Benth. ex Kurz (Apocynaceae) on Murashige Skoog (1962) medium supplemented with 1mg/l 2,4-Dichlorophenocy acetic acid (2,4-D) and 1mg/l Kinetin (Kn). Vigorous growth of callus occurs after 4 weeks of culture. Callus was sub-cultured on Murashige and Skoog (MS) medium supplemented with different concentration of 2, 4-D (0.5-3.0 mg/l) and 10% coconut milk. Regeneration of plantlets occurred on MS medium containing 3 mg/1 of 2, 4-D and 10% coconut milk. These plantlets were rooted on MS medium supplemented with 1 mg/l IAA .The regenerated plantlets were able to grow on soil after short period ofacclimatization. Key words: Explant; In-vitro culture; MS medium;  2, 4 Dichlorophenoxy acetic acid; Kinetin; Callus; Tissue culture; Coconut milk. Journal of Natural History Museum Vol. 24, 2009 Page: 82-88

Advancement Of Changed Pulsincap Medicate Conveyance Arrangement Of Metronidazole For Tranquilize Focusing

2020 ◽  
Vol 2 (05) ◽  
pp. I-IV
Author(s):  
Roshni Jha ◽  
Anjali Minj
Keyword(s):  
Acetic Acid ◽  
Sodium Alginate ◽  
Guar Gum

A changed Pulsincap measurements type of metronidazole was created to target tranquilize discharge in the colon. Groups of hard gelatin cases were treated with formaldehyde keeping the tops in that capacity. Metronidazole pellets arranged by expulsion spheronization technique were consolidated into these particular container shells and stopped with polymers guar gum, hydroxypropylmethylcellulose 10K, carboxymethylcellulose sodium and sodium alginate independently at fixations 20 mg, 30 mg and 40 mg. The filled cases were totally covered with 5% cellulose acetic acid derivation phthalate to forestall variable gastric purging. All the definitions were tested to decide sedate substance and the capacity of the adjusted Pulsincap to give colon-explicit medication conveyance was surveyed by in vitro tranquilize discharge concentrates in cushion pH 1.2 for 2 h, pH 7.4 (reproduced intestinal liquid) for 3 h and pH 6.8 (animated colonic liquid) for 7 h. The outcomes showed that critical medication discharge happened simply after 5 h from the beginning of analysis.

Sign in / Sign up

Export Citation Format

Share Document