scholarly journals Role of ctc from Listeria monocytogenes in Osmotolerance

2003 ◽  
Vol 69 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Rozenn Gardan ◽  
Ophélie Duché ◽  
Sabine Leroy-Sétrin ◽  
Jean Labadie
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Minimal Medium ◽  
Stress Protein ◽  
Transcriptional Level ◽  
Osmotic Stress Tolerance ◽  
Electron Microscopy Analysis

ABSTRACT Listeria monocytogenes is a food-borne pathogen with the ability to grow under conditions of high osmolarity. In a previous study, we reported the identification of 12 proteins showing high induction after salt stress. One of these proteins is highly similar to the general stress protein Ctc of Bacillus subtilis. In this study, induction of Ctc after salt stress was confirmed at the transcriptional level by using RNA slot blot experiments. To explore the role of the ctc gene product in resistance to stresses, we constructed a ctc insertional mutant. No difference in growth was observed between the wild-type strain LO28 and the ctc mutant either in rich medium after osmotic or heat stress or in minimal medium after heat stress. However, in minimal medium after osmotic stress, the growth rate of the mutant was increased by a factor of 2. Moreover, electron microscopy analysis showed impaired morphology of the mutant grown under osmotic stress conditions in minimal medium. Addition of the osmoprotectant glycine betaine to the medium completely abolished the osmotic sensitivity phenotype of the ctc mutant. Altogether, these results suggest that the Ctc protein of L. monocytogenes is involved in osmotic stress tolerance in the absence of any osmoprotectant in the medium.

scholarly journals Hydrogen sulfide and potassium synergistically induce osmotic stress tolerance through regulation of H+-ATPase activity and sugar metabolism in tomato seedlings

2021 ◽  
Author(s):  
Manzer H. Siddiqui ◽  
Soumya Mukherjee ◽  
Saud Alamri ◽  
Yanbo Hu ◽  
Abdullah Alamri ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Osmotic Stress ◽  
Atpase Activity ◽  
Channel Blocker ◽  
Sugar Metabolism ◽  
Decisive Role ◽  
K Channel ◽  
Tomato Seedlings ◽  
Osmotic Stress Tolerance

Abstract Potassium (K) is an essential macronutrient which is known to regulate key metabolic processes, modulate enzyme activity and plays a decisive role in osmotic adjustment in plants. Present work evaluates the role of K in the regulation of endogenous hydrogen sulfide (H2S) signaling in modulating the tolerance of tomato (Solanum lycopersicum L. Mill.) seedlings to osmotic stress. The findings reveal that exposure of seedlings to 15% (w/v) polyethylene glycol 8000 (PEG) led to a substantial decrease in leaf K content which was associated with reduced H+-ATPase activity. Exogenous application of K to the stressed seedlings significantly improved endogenous K content. Treatment with sodium orthovanadate (SOV, PM H+-ATPase inhibitor) and tetraethylammonium chloride (TEA, K channel blocker) suggests that exogenous K stimulated H+-ATPase activity that further regulated endogenous K content in tomato seedlings subjected to osmotic stress. Moreover, reduction in H+-ATPase activity by hypotaurine (H2S scavenger) substantiates the role of endogenous H2S in the regulation of H+-ATPase activity. Elevation in endogenous K content enhanced the biosynthesis of hydrogen sulfide (H2S) through enhancing the synthesis of cysteine, the H2S precursor. Synergistic action of H2S and K effectively neutralized osmotic stress by regulating sugar metabolism that resulted in osmotic adjustment, as witnessed by reduced water loss and improved hydration level of the stressed seedlings. Cross talk of H2S and K also assisted the seedlings in the activation of antioxidant enzymes that controlled the generation of reactive oxygen species and led to the protection against oxidative stress. The integrative role of H2S and K signaling was validated using hypotaurine (H2S scavenger) and TEA (K channel blocker) which weakened the protection against osmotic stress induced impairments. In conclusion, exogenous K and endogenous H2S regulate H+-ATPase activity which plays a decisive role in the maintenance of endogenous K homeostasis. Thus, present work reveals that K and H2S crosstalk is essential for modulation of osmotic stress tolerance in tomato seedlings.

scholarly journals Role of Silicon in Mediating Salt Tolerance in Plants: A Review

Plants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 147 ◽  
Author(s):  
Yong-Xing Zhu ◽  
Hai-Jun Gong ◽  
Jun-Liang Yin
Keyword(s):  
Oxidative Stress ◽  
Salt Stress ◽  
Osmotic Stress ◽  
Stress Responses ◽  
Polyamine Metabolism ◽  
Research Areas ◽  
Aquaporin Gene ◽  
Ion Imbalance ◽  
The Impact

Salt stress is a major threat for plant growth worldwide. The regulatory mechanisms of silicon in alleviating salt stress have been widely studied using physiological, molecular genetics, and genomic approaches. Recently, progresses have been made in elucidating the alleviative effects of silicon in salt-induced osmotic stress, Na toxicity, and oxidative stress. In this review, we highlight recent development on the impact of silicon application on salt stress responses. Emphasis will be given to the following aspects. (1) Silicon transporters have been experimentally identified in different plant species and their structure feature could be an important molecular basis for silicon permeability. (2) Silicon could mediate salt-induced ion imbalance by (i) regulating Na+ uptake, transport, and distribution and (ii) regulating polyamine levels. (3) Si-mediated upregulation of aquaporin gene expression and osmotic adjustment play important roles in alleviating salinity-induced osmotic stress. (4) Silicon application direct/indirectly mitigates oxidative stress via regulating the antioxidant defense and polyamine metabolism. (5) Omics studies reveal that silicon could regulate plants’ response to salt stress by modulating the expression of various genes including transcription factors and hormone-related genes. Finally, research areas that require further investigation to provide a deeper understanding of the role of silicon in plants are highlighted.

Physiological and metabolomic analysis of a knockout mutant suggests a critical role of MtP5CS3 gene in osmotic stress tolerance of Medicago truncatula

Euphytica ◽  
2013 ◽  
Vol 193 (1) ◽  
pp. 101-120 ◽  
Author(s):  
Minh Luan Nguyen ◽  
Goon-Bo Kim ◽  
Sun-Hee Hyun ◽  
Seok-Young Lee ◽  
Chae-Young Lee ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Stress Tolerance ◽  
Medicago Truncatula ◽  
Critical Role ◽  
Metabolomic Analysis ◽  
Knockout Mutant ◽  
Osmotic Stress Tolerance

Role of Sigma B Factor in the Alkaline Tolerance Response of Listeria monocytogenes 10403S and Cross-Protection against Subsequent Ethanol and Osmotic Stress

2008 ◽  
Vol 71 (7) ◽  
pp. 1481-1485 ◽  
Author(s):  
EFSTATHIOS S. GIOTIS ◽  
MUDCHAREE JULOTOK ◽  
BRIAN J. WILKINSON ◽  
IAN S. BLAIR ◽  
DAVID A. MCDOWELL
Keyword(s):  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Surface Cleaning ◽  
Cross Protection ◽  
Ethanol Stress ◽  
Alkaline Ph ◽  
Alkaline Tolerance ◽  
Wide Range ◽  
Type Strains

Many of the considerable abilities of Listeria monocytogenes to persist and grow in a wide range of adverse environmental conditions are thought to be at least partly under the control of the alternative sigma factor (σB), encoded by the sigB gene. However, little is known about the role of this master regulon in the impressive ability of Listeria to persist and grow under conditions of alkaline pH. In this study, Northern blot analysis of parent Listeria mRNA revealed that alkali adaptation (pH 9.5 for 1 h) significantly increased the expression of sigB-derived mRNA. The study included a comparison of the relative survival of mid-exponential populations of adapted and nonadapted parent type (σB expressing) and mutant (not σB expressing, ΔsigB) Listeria strains during subsequent alkaline (pH 12.0), osmotic (25% NaCl, wt/vol), or ethanol (16.5%) stress. Alkali-adapted parent strains were more resistant to pH 12.0 than were adapted ΔsigB type strains, but both alkali-adapted parent and ΔsigB strains were more resistant to pH 12.0 than were nonadapted strains. Alkali-adapted parent strains were more resistant to osmotic stress than were adapted ΔsigB type strains. No significant differences in viability were observed between alkali-adapted parent and ΔsigB strains after ethanol stress, suggesting that cross-protection against osmotic stress is mediated by σB whereas cross-protection against ethanol is σB independent. Overall, alkali-induced cross-protection against osmotic and ethanol challenges may have serious implications for food safety and human health because such stress conditions are routinely used as part of food preservation and surface cleaning processes.

scholarly journals Listeria monocytogenes Shows Temperature-Dependent and -Independent Responses to Salt Stress, Including Responses That Induce Cross-Protection against Other Stresses

2012 ◽  
Vol 78 (8) ◽  
pp. 2602-2612 ◽  
Author(s):  
Teresa M. Bergholz ◽  
Barbara Bowen ◽  
Martin Wiedmann ◽  
Kathryn J. Boor
Keyword(s):  
Salt Stress ◽  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Parent Strain ◽  
Cross Protection ◽  
Temperature Dependent ◽  
Short Term ◽  
Transcript Levels ◽  
Content Type ◽  
Short Term Adaptation

ABSTRACTThe food-borne pathogenListeria monocytogenesexperiences osmotic stress in many habitats, including foods and the gastrointestinal tract of the host. During transmission,L. monocytogenesis likely to experience osmotic stress at different temperatures and may adapt to osmotic stress in a temperature-dependent manner. To understand the impact of temperature on the responses this pathogen uses to adapt to osmotic stress, we assessed genome-wide changes in theL. monocytogenesH7858 transcriptome during short-term and long-term adaptation to salt stress at 7°C and 37°C. At both temperatures, the short-term response to salt stress included increased transcript levels ofsigBand SigB-regulated genes, as well asmrpABCDEFG, encoding a sodium/proton antiporter. This antiporter was found to play a role in adaptation to salt stress at both temperatures; ΔmrpABCDEFGhad a significantly longer lag phase than the parent strain in BHI plus 6% NaCl at 7°C and 37°C. The short-term adaptation to salt stress at 7°C included increased transcript levels of two genes encoding carboxypeptidases that modify peptidoglycan. These carboxypeptidases play a role in the short-term adaptation to salt stress only at 7°C, where the deletion mutants had significantly different lag phases than the parent strain. Changes in the transcriptome at both temperatures suggested that exposure to salt stress could provide cross-protection to other stresses, including peroxide stress. Short-term exposure to salt stress significantly increased H2O2resistance at both temperatures. These results provide information for the development of knowledge-based intervention methods against this pathogen, as well as provide insight into potential mechanisms of cross-protection.

scholarly journals Osmotic stress in banana is relieved by exogenous nitric oxide

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10879 ◽  
Author(s):  
Muhammad Asyraf Mohd Amnan ◽  
Teen-Lee Pua ◽  
Su-Ee Lau ◽  
Boon Chin Tan ◽  
Hisateru Yamaguchi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Plant Growth ◽  
Osmotic Stress ◽  
Higher Plants ◽  
Antioxidant Enzyme Activities ◽  
Label Free ◽  
Defensive Responses ◽  
Osmotic Stress Tolerance ◽  
Nano Liquid Chromatography

Drought is one of the severe environmental stresses threatening agriculture around the globe. Nitric oxide plays diverse roles in plant growth and defensive responses. Despite a few studies supporting the role of nitric oxide in plants under drought responses, little is known about its pivotal molecular amendment in the regulation of stress signaling. In this study, a label-free nano-liquid chromatography-mass spectrometry approach was used to determine the effects of sodium nitroprusside (SNP) on polyethylene glycol (PEG)-induced osmotic stress in banana roots. Plant treatment with SNP improved plant growth and reduced the percentage of yellow leaves. A total of 30 and 90 proteins were differentially identified in PEG+SNP against PEG and PEG+SNP against the control, respectively. The majority of proteins differing between them were related to carbohydrate and energy metabolisms. Antioxidant enzyme activities, such as superoxide dismutase and ascorbate peroxidase, decreased in SNP-treated banana roots compared to PEG-treated banana. These results suggest that the nitric oxide-induced osmotic stress tolerance could be associated with improved carbohydrate and energy metabolism capability in higher plants.

scholarly journals Physiological and Molecular Responses of Six Apple Rootstocks to Osmotic Stress

2021 ◽  
Vol 22 (15) ◽  
pp. 8263
Author(s):  
Yasmine S. Hezema ◽  
Mukund R. Shukla ◽  
Murali M. Ayyanath ◽  
Sherif M. Sherif ◽  
Praveen K. Saxena
Keyword(s):  
Osmotic Stress ◽  
Stomatal Closure ◽  
Transcriptional Level ◽  
Limited Information ◽  
Apple Rootstocks ◽  
Molecular Responses ◽  
Osmotic Stress Tolerance ◽  
Relative Water ◽  
Response To Stress ◽  
Use Efficiency

The growth and productivity of several apple rootstocks have been evaluated in various previous studies. However, limited information is available on their tolerance to osmotic stress. In the present study, the physiological and molecular responses as well as abscisic acid (ABA) levels were assessed in six apple rootstocks (M26, V3, G41, G935, B9 and B118) osmotically stressed with polyethylene glycol (PEG, 30%) application under greenhouse conditions. Our results showed that V3, G41, G935 and B9 had higher relative water content (RWC), and lower electrolyte leakage (EL) under stress conditions compared to M26 and B118. Additionally, water use efficiency (WUE) was higher in V3, G41 and B9 than M26, which might be partially due to the lower transpiration rate in these tolerant rootstocks. V3, G41 and B9 rootstocks also displayed high endogenous ABA levels which was combined with a reduction in stomatal conductance and decreased water loss. At the transcriptional level, genes involved in ABA-dependent and ABA-independent pathways, e.g., SnRK, DREB, ERD and MYC2, showed higher expression in V3, G41, G935 and B9 rootstocks compared to M26 in response to stress. In contrast, WRKY29 was down-regulated in response to stress in the tolerant rootstocks, and its expression was negatively correlated with ABA content and stomatal closure. Overall, the findings of this study showed that B9, V3 and G41 displayed better osmotic stress tolerance followed by G935 then M26 and B118 rootstocks.

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