Alkyl hydroperoxide reductase is important for oxidative stress resistance and symbiosis in<i>Azorhizobium caulinodans</i>

Jiang, Gaofei; Yang, Juan; Li, Xingjuan; Cao, Yajun; Liu, Xiaomeng; Ling, Jun; Wang, Hui; Zhong, Zengtao; Zhu, Jun

doi:10.1093/femsle/fnz014

Cited by 12 publications

(14 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…caulinodans and other rhizobia must be able to withstand oxidative stress in the host environment to establish successful symbiotic relationships with the host plants. At the first encounter with S. rostrata, A. caulinodans is recognised as an invader and triggers an oxidative burst [11,18,67]. OHPs are produced by host plants as a part of the defence response against bacterial infection, and subsequently react with free fatty acids and cell membranes, leading to the production of other organic radicals, which increases their toxicity [26].…”

Section: Discussionmentioning

confidence: 99%

“…This suggested OhrR might repress ohr expression, and that CuOOH functions as an inducer. OHPs are principally degraded by the Ohr system in A. caulinodans, as AhpC and BCP are involved in the scavenging of H 2 O 2 but not OHPs [18,19].…”

Section: Discussionmentioning

confidence: 99%

“…Ohr and OhrR have been studied in several types of bacteria; however, little is known regarding the role of these proteins in rhizobia. Although our previous study investigated the H 2 O 2 scavenging systems in A. caulinodans, the OHPs resistance network remains poorly understood [17][18][19]. The present study scrutinized the functional role of the ohr and ohrR genes in A. caulinodans ORS571.…”

Section: Introductionmentioning

confidence: 95%

“…The first involves the well-characterised enzyme AhpC, which is a member of the peroxiredoxin family and it degrades both organic and inorganic peroxides [23][24][25]. However, our previous study revealed that, in A. caulinodans, AhpC was involved in the detoxification of H 2 O 2 , but not OHPs [18]. The other enzyme that is involved in the detoxification of OHPs is the organic hydroperoxide resistance protein (Ohr), first discovered in Xanthomonas campestris [26], which was later revealed to be widely distributed in bacteria [27][28][29].…”

Section: Introductionmentioning

confidence: 98%

“…Consequently, A. caulinodans has evolved several types of ROS scavenging systems for sensing, regulating, and protecting against ROS toxicity from the host. In our previous work, we have comprehensively studied several antioxidant enzymes in A. caulinodans, such as catalase (KatG) [17], alkyl hydroperoxide reductase (AhpC) [18], and bacterioferritin comigratory protein (BCP) [19], which are all involved in detoxifying exogenous H 2 O 2 , and affect the nodulation behaviour and nitrogen fixation in S. rostrata [17][18][19]. However, plants produce additional substances as part of the active defence response, such as organic hydroperoxides (OHPs) [20,21].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Ohr and OhrR Are Critical for Organic Peroxide Resistance and Symbiosis in Azorhizobium caulinodans ORS571

Guo

Deng

et al. 2020

Genes

Self Cite

View full text Add to dashboard Cite

Azorhizobium caulinodans is a symbiotic nitrogen-fixing bacterium that forms both root and stem nodules on Sesbania rostrata. During nodule formation, bacteria have to withstand organic peroxides that are produced by plant. Previous studies have elaborated on resistance to these oxygen radicals in several bacteria; however, to the best of our knowledge, none have investigated this process in A. caulinodans. In this study, we identified and characterised the organic hydroperoxide resistance gene ohr (AZC_2977) and its regulator ohrR (AZC_3555) in A. caulinodans ORS571. Hypersensitivity to organic hydroperoxide was observed in an ohr mutant. While using a lacZ-based reporter system, we revealed that OhrR repressed the expression of ohr. Moreover, electrophoretic mobility shift assays demonstrated that OhrR regulated ohr by direct binding to its promoter region. We showed that this binding was prevented by OhrR oxidation under aerobic conditions, which promoted OhrR dimerization and the activation of ohr. Furthermore, we showed that one of the two conserved cysteine residues in OhrR, Cys11, was critical for the sensitivity to organic hydroperoxides. Plant assays revealed that the inactivation of Ohr decreased the number of stem nodules and nitrogenase activity. Our data demonstrated that Ohr and OhrR are required for protecting A. caulinodans from organic hydroperoxide stress and play an important role in the interaction of the bacterium with plants. The results that were obtained in our study suggested that a thiol-based switch in A. caulinodans might sense host organic peroxide signals and enhance symbiosis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Ohr and OhrR Are Critical for Organic Peroxide Resistance and Symbiosis in Azorhizobium caulinodans ORS571

Guo

Deng

et al. 2020

Genes

Self Cite

View full text Add to dashboard Cite

show abstract

Cold-adapted characteristics and gene knockout of alkyl hydroperoxide reductase subunit C in Antarctic Psychrobacter sp. ANT206

Hou,

Qiao,

Hou

et al. 2024

World J Microbiol Biotechnol

View full text Add to dashboard Cite

A novel mycothiol-dependent thiol–disulfide reductase in Corynebacterium glutamicum involving oxidative stress resistance

Liu

Luo

et al. 2021

3 Biotech

View full text Add to dashboard Cite

Abstractncgl2478 gene from Corynebacterium glutamicum encodes a thiol–disulfide oxidoreductase enzyme annotated as dithiol–disulfide isomerase DsbA. It preserves a Cys–Pro–Phe–Cys active-site motif, which is presumed to be an exclusive characteristic of the novel DsbA–mycoredoxin 1 (Mrx1) cluster. However, the real mode of action, the nature of the electron donor pathway and biological functions of NCgl2478 in C. glutamicum have remained enigmatic so far. Herein, we report that NCgl2478 plays an important role in stress resistance. Deletion of the ncgl2478 gene increases the size of growth inhibition zones. The ncgl2478 expression is induced in the stress-responsive extra-cytoplasmic function-sigma (ECF-σ) factor SigH-dependent manner by stress. It receives electrons preferentially from the mycothiol (MSH)/mycothione reductase (Mtr)/NADPH pathway. Further, NCgl2478 reduces S-mycothiolated mixed disulfides and intramolecular disulfides via a monothiol–disulfide and a dithiol–disulfide exchange mechanism, respectively. NCgl2478 lacks oxidase activity; kinetic properties of its demycothiolation are different from those of Mrx1. Site-directed mutagenesis confirms Cys24 is the resolving Cys residue, while Cys21 is the nucleophilic cysteine that is oxidized to a sulfenic acid and then forms an intramolecular disulfide bond with Cys24 or a mixed disulfide with MSH under oxidative stress. In conclusion, our study presents the first evidence that NCgl2478 protects against various stresses by acting as an MSH-dependent thiol–disulfide reductase, belonging to a novel DsbA–Mrx1 cluster.

show abstract

Alkyl hydroperoxide reductase is important for oxidative stress resistance and symbiosis inAzorhizobium caulinodans

Cited by 12 publications

References 47 publications

Ohr and OhrR Are Critical for Organic Peroxide Resistance and Symbiosis in Azorhizobium caulinodans ORS571

Ohr and OhrR Are Critical for Organic Peroxide Resistance and Symbiosis in Azorhizobium caulinodans ORS571

Cold-adapted characteristics and gene knockout of alkyl hydroperoxide reductase subunit C in Antarctic Psychrobacter sp. ANT206

A novel mycothiol-dependent thiol–disulfide reductase in Corynebacterium glutamicum involving oxidative stress resistance

Contact Info

Product

Resources

About