Isolation and characterization of an atypical LEA gene (IpLEA) from Ipomoea pes-caprae conferring salt/drought and oxidative stress tolerance

Abstract Late embryogenesis abundant (LEA) proteins belong to a large family that exists widely in plants and is mainly involved in desiccation processes during plant development or in the response to abiotic stresses. Here, we reported on an atypical LEA gene (IpLEA) related to salt tolerance from Ipomoea pes-caprae L. (Convolvulaceae). Sequence analysis revealed that IpLEA belongs to the LEA_2 (PF03168) group. IpLEA was shown to have a cytoplasmic localization pattern. Quantitative reverse transcription PCR analysis showed that IpLEA was widely expressed in different organs of the I. pes-caprae plants, and the expression levels increased following salt, osmotic, oxidative, freezing, and abscisic acid treatments. Analysis of the 1,495 bp promoter of IpLEA identified distinct cis-acting regulatory elements involved in abiotic stress. Induction of IpLEA improved Escherichia coli growth performance compared with the control under abiotic stresses. To further assess the function of IpLEA in plants, transgenic Arabidopsis plants overexpressing IpLEA were generated. The IpLEA-overexpressing Arabidopsis seedlings and adult plants showed higher tolerance to salt and drought stress than the wild-type. The transgenic plants also showed higher oxidative stress tolerance than the wild-type Arabidopsis. Furthermore, the expression patterns of a series of stress-responsive genes were affected. The results indicate that IpLEA is involved in the plant response to salt and drought, probably by mediating water homeostasis or by acting as a reactive oxygen species scavenger, thereby influencing physiological processes under various abiotic stresses in microorganisms and plants.

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The Streptococcus mutans vicX Gene Product Modulates gtfB/C Expression, Biofilm Formation, Genetic Competence, and Oxidative Stress Tolerance

Journal of Bacteriology ◽

10.1128/jb.01161-06 ◽

2006 ◽

Vol 189 (4) ◽

pp. 1451-1458 ◽

Cited By ~ 62

Author(s):

M. Dilani Senadheera ◽

Andrew W. C. Lee ◽

David C. I. Hung ◽

Grace A. Spatafora ◽

Steven D. Goodman ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Tolerance ◽

Gene Product ◽

Streptococcus Mutans ◽

Parent Strain ◽

Adhesion Assay ◽

Wild Type ◽

Coding Region ◽

Oxidative Stress Tolerance ◽

Cell Clusters

ABSTRACT Streptococcus mutans is considered one of the primary etiologic agents of dental caries. Previously, we characterized the VicRK two-component signal transduction system, which regulates multiple virulence factors of S. mutans. In this study, we focused on the vicX gene of the vicRKX tricistronic operon. To characterize vicX, we constructed a nonpolar deletion mutation in the vicX coding region in S. mutans UA159. The growth kinetics of the mutant (designated SmuvicX) showed that the doubling time was longer and that there was considerable sensitivity to paraquat-induced oxidative stress. Supplementing a culture of the wild-type UA159 strain with paraquat significantly increased the expression of vicX (P < 0.05, as determined by analysis of variance [ANOVA]), confirming the role of this gene in oxidative stress tolerance in S. mutans. Examination of mutant biofilms revealed architecturally altered cell clusters that were seemingly denser than the wild-type cell clusters. Interestingly, vicX-deficient cells grown in a glucose-supplemented medium exhibited significantly increased glucosyltransferase B/C (gtfB/C) expression compared with the expression in the wild type (P < 0.05, as determined by ANOVA). Moreover, a sucrose-dependent adhesion assay performed using an S. mutans GS5-derived vicX null mutant demonstrated that the adhesiveness of this mutant was enhanced compared with that of the parent strain and isogenic mutants of the parent strain lacking gtfB and/or gtfC. Also, disruption of vicX reduced the genetic transformability of the mutant approximately 10-fold compared with that of the parent strain (P < 0.05, as determined by ANOVA). Collectively, these findings provide insight into important phenotypes controlled by the vicX gene product that can impact S. mutans pathogenicity.

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Phenotyping dauer juvenile oxidative stress tolerance, longevity and persistence within wild type and inbred lines of the entomopathogenic nematode Heterorhabditis bacteriophora

Nematology ◽

10.1163/15685411-00003100 ◽

2017 ◽

Vol 19 (8) ◽

pp. 971-986 ◽

Cited By ~ 1

Author(s):

Nanette Hope Sumaya ◽

Sitaram Aryal ◽

Bart Vandenbossche ◽

Mike Barg ◽

Verena Doerfler ◽

...

Keyword(s):

Oxidative Stress ◽

Shelf Life ◽

Stress Tolerance ◽

Entomopathogenic Nematode ◽

Heterorhabditis Bacteriophora ◽

Inbred Lines ◽

Wild Type ◽

Oxidative Stress Tolerance ◽

Metabolic Imbalance ◽

In Transit

The commercial use of the entomopathogenic nematodeHeterorhabditis bacteriophoraas a biocontrol agent against noxious insects is limited due to its relatively short shelf-life. Longevity of dauer juveniles (DJ) during storage and in transit to end users is considerably restricted by environmental stresses. As a derivative stress triggered by environmental factors, oxidative stress causes a strong internal metabolic imbalance leading to lifespan reduction. In this study, the relation between DJ oxidative stress tolerance and longevity inH. bacteriophorawas investigated at 25 and 7°C. A strong and significant correlation between DJ oxidative stress tolerance and longevity during storage in Ringer’s solution ( at 7°C; at 25°C) was recorded. Phenotyping of these traits was performed for 40H. bacteriophorawild type strain and inbred line collections. At 25°C, the mean time survived in Ringer’s by 50% of the DJ (MTS50) ranged from 21 to 57 days, whereas under oxidative stress, survival was from 3 to 22 days. At 7°C, a maximum MTS50of 94 days was assessed when DJ were stored in Ringer’s, while the maximum MTS50was only 25 days with oxidative stress induction. The heritability of DJ tolerance to oxidative stress, determined by using homozygous inbred lines, is high (), an indication of a high probability for successful selective breeding. In a subset of preselectedH. bacteriophorainbred lines, DJ oxidative stress tolerance correlated with the DJ survival (persistence) after application to sand (). The study provides fundamental data required for a genetic breeding programme to produce hybrids with improved stress tolerance and prolonged shelf-life and soil persistence.

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Up-Regulated Galectin-1 in Angiostrongylus Cantonensis L5 Reduces Body Fat and Increases Oxidative Stress Tolerance

10.21203/rs.3.rs-832396/v1 ◽

2021 ◽

Author(s):

Weiwei Sun ◽

Xiumei Yan ◽

Aijun Qiao ◽

Yuanjiao Zhang ◽

Ling Yang ◽

...

Keyword(s):

Oxidative Stress ◽

Central Nervous System ◽

Nervous System ◽

Stress Tolerance ◽

Inflammatory Responses ◽

Expression Patterns ◽

Angiostrongylus Cantonensis ◽

Lipid Deposition ◽

Oxidative Stress Tolerance ◽

The Central Nervous System

Abstract Background: Angiostrongylus cantonensis L5, parasitizing in human cerebrospinal fluid, leads to eosinophilic meningitis, which is attributed to tissue inflammatory responses caused primarily by high percentage of eosinophils. Eosinophils are also involved in helminthic killing, using the peroxidative oxidation and hydrogen peroxide (H2O2) generated by dismutation of superoxide produced during respiratory burst. In contrast, helminthic worms have evolved to attenuate eosinophil-mediated tissue inflammatory responses for their survival. In previous study, we have demonstrated the extracellular function of Acan-Gal-1 in inducing the apoptosis of macrophages. And here, the intracellular functions of Acan-Gal-1 were investigated with the aim to further reveal the mechanism of A. cantonensis L5 worms surviving in the central nervous system of human from inflammatory responses. Methods: Bioinformatics were used to analyse the structural characterisation of Acan-Gal-1; qRT-PCR and microinjection were performed to detect the expression patterns of Acan-gal-1; microinjection was performed to construct transgenic worms; oxidative stress assay and Oil Red O fat staining were used to determine the functions of Acan-Gal-1.Results: The results showed that Acan-Gal-1 was expressed ubiquitously and mainly localized in cuticle, and it was up-regulated in both L5 and adult worm. N2 worms expressing pCe-Acan-gal-1::Acan-gal-1::rfp, with lipid deposition reduced, were significantly resistant to oxidative stress. lec-1 mutant worms, with lipid deposition increased, showed susceptible to oxidative stress, and this phenotype could be rescued by expressing pCe-Acan-gal-1::Acan-gal-1::rfp. And fat-6;fat-7 double-mutant worms expressing pCe-Acan-gal-1::Acan-gal-1::rfp showed no significant changes in oxidative stress tolerance.Conclusion: In C. elegans worms, up-regulated Acan-Gal-1 plays a defensive role against damage due to oxidative stress for worm survival through reducing fat deposition. And this might indicate the mechanism of A. cantonensis L5 worms, with Acan-Gal-1 up-regulated, surviving in the central nervous system of human from immune attack of Eosinophil.

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Molecular cloning and expression analysis of a stress-responsive WRKY transcription factor gene, BnWRKY57, from Brassica napus

Plant Omics ◽

10.21475/poj.12.01.19.pt1792 ◽

2019 ◽

pp. 37-47 ◽

Cited By ~ 4

Author(s):

Fatemeh Atashi Shirazi ◽

Hooman Razi ◽

Ali Niazi ◽

Abbas Alemzadeh

Keyword(s):

Brassica Napus ◽

Abiotic Stresses ◽

Expression Patterns ◽

Regulatory Elements ◽

Wrky Transcription Factor ◽

Cloning And Expression ◽

Pcr Analysis ◽

Coding Region ◽

Transgenic Breeding ◽

Drought And Salt Stresses

WRKY transcription factors play important roles in regulation of various plant biological processes, including response to abiotic stresses. WRKY genes might be potential targets for transgenic breeding to enhance stress tolerance in rapeseed (Brassica napus). The present study aimed to clone and characterize WRKY57 (BnWRKY57) gene derived from B. napus and to analyze patterns of BnWRKY57 expression under drought and salt stresses in two B. napus cultivars with different levels of tolerance to drought and salt. The full-length coding region of BnWRKY57 gene with 882bp long (GenBank Accession Number: MG699908) was cloned and sequenced. BnWRKY57 gene encodes a hydrophilic polypeptide of 293 amino acids. It shared high homology with other known WRKY57s from Brassicaceae family. The promoter of BnWRKY57 gene contained cis regulatory elements involved in response to phytohormones, light, biotic and abiotic stresses suggesting this gene may play a role to modulate different signaling pathways. Real time quantitative RT-PCR analysis revealed that BnWRKY57 expression was responsive to drought and salt stresses. BnWRKY57 gene showed different expression patterns between leaves and roots and also between the B. napus cultivars under stress conditions. Overall, the findings suggest that BnWRKY57 gene may contribute to adaptive responses to drought and salt stresses in B. napus.

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