Growth-Promoting Gold Nanoparticles Decrease Stress Responses in Arabidopsis Seedlings

The global economic success of man-made nanoscale materials has led to a higher production rate and diversification of emission sources in the environment. For these reasons, novel nanosafety approaches to assess the environmental impact of engineered nanomaterials are required. While studying the potential toxicity of metal nanoparticles (NPs), we realized that gold nanoparticles (AuNPs) have a growth-promoting rather than a stress-inducing effect. In this study we established stable short- and long-term exposition systems for testing plant responses to NPs. Exposure of plants to moderate concentrations of AuNPs resulted in enhanced growth of the plants with longer primary roots, more and longer lateral roots and increased rosette diameter, and reduced oxidative stress responses elicited by the immune-stimulatory PAMP flg22. Our data did not reveal any detrimental effects of AuNPs on plants but clearly showed positive effects on growth, presumably by their protective influence on oxidative stress responses. Differential transcriptomics and proteomics analyses revealed that oxidative stress responses are downregulated whereas growth-promoting genes/proteins are upregulated. These omics datasets after AuNP exposure can now be exploited to study the underlying molecular mechanisms of AuNP-induced growth-promotion.

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Biological links between nanoparticle biosynthesis and stress responses in bacteria

Mexican Journal of Biotechnology ◽

10.29267/mxjb.2018.3.4.44 ◽

2018 ◽

Vol 3 (4) ◽

pp. 44-69

Author(s):

Angela Chen ◽

Benjamin K. Keitz ◽

Lydia M. Contreras

Keyword(s):

Oxidative Stress ◽

Resistance Genes ◽

Stress Responses ◽

Molecular Mechanisms ◽

Metal Resistance ◽

Reduction Mechanisms ◽

Nanoparticle Morphology ◽

Nanoparticle Biosynthesis ◽

Oxidative Stress Responses

There is rising interest in nanoparticle biosynthesis using bacteria due to the potential for applications in bioremediation, catalysis, or as antimicrobials. However, biosynthesis remains limited by the inability to control nanoparticle morphology and size due to the lack of knowledge regarding explicit molecular mechanisms. Due to their importance in nanoparticle biosynthesis and as antimicrobials, we focus our discussion on silver, gold, and copper nanoparticles. We discuss recent efforts to elucidate reduction mechanisms that have identified generic enzymes and metal resistance genes as strong candidates to facilitate nanoparticle biosynthesis. Although it is known that these enzymes and genes play significant roles in maintaining bacterial homeostasis, there are few reports discussing this topic. Thus, we discuss examples of how metal resistance genes are conserved across bacteria and have been shown to be important for both nanoparticle biosynthesis and processes such as virulence or oxidative stress responses. Overall, this review highlights biological connections between nanoparticle biosynthesis and stress responses by examining the role of reductases and metal resistance genes in both processes. This understanding provides a greater role for nanoparticle biosynthesis in bacteria and could enable a systems biology level of control over nanoparticle biosynthesis.

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Repressive effect of Rhus coriaria L. fruit extracts on microglial cells-mediated inflammatory and oxidative stress responses

Journal of Ethnopharmacology ◽

10.1016/j.jep.2020.113748 ◽

2021 ◽

Vol 269 ◽

pp. 113748

Author(s):

Mohamad Khalil ◽

Ali Bazzi ◽

Dana Zeineddine ◽

Wissam Jomaa ◽

Ahmad Daher ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Responses ◽

Microglial Cells ◽

Fruit Extracts ◽

Repressive Effect ◽

Rhus Coriaria ◽

Oxidative Stress Responses ◽

And Oxidative Stress

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Dynamic aqueous transformations of lithium cobalt oxide nanoparticle induce distinct oxidative stress responses of B. subtilis

Environmental Science Nano ◽

10.1039/d0en01151g ◽

2021 ◽

Author(s):

Metti K. Gari ◽

Paul Lemke ◽

Kelly H. Lu ◽

Elizabeth D. Laudadio ◽

Austin H. Henke ◽

...

Keyword(s):

Oxidative Stress ◽

Cobalt Oxide ◽

Stress Responses ◽

Lithium Ion ◽

Model Organisms ◽

Lithium Cobalt Oxide ◽

Oxygen Species ◽

Oxide Nanoparticle ◽

Oxidative Stress Responses ◽

Lithium Cobalt

Lithium cobalt oxide (LiCoO2), an example of nanoscale transition metal oxide and a widely commercialized cathode material in lithium ion batteries, has been shown to induce oxidative stress and generate intracellular reactive oxygen species (ROS) in model organisms.

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The Arabidopsis mediator complex subunit 8 regulates oxidative stress responses

The Plant Cell ◽

10.1093/plcell/koab079 ◽

2021 ◽

Cited By ~ 1

Author(s):

Huaming He ◽

Jordi Denecker ◽

Katrien Van Der Kelen ◽

Patrick Willems ◽

Robin Pottie ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Stress Responses ◽

Negative Regulator ◽

Mediator Complex ◽

Defense Gene Expression ◽

A Genome ◽

Oxidative Stress Responses

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.

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Clade III cytokinin response factors share common roles in response to oxidative stress responses linked to cytokinin synthesis

Journal of Experimental Botany ◽

10.1093/jxb/erab076 ◽

2021 ◽

Vol 72 (8) ◽

pp. 3294-3306

Author(s):

Ariel M Hughes ◽

H Tucker Hallmark ◽

Lenka Plačková ◽

Ondrej Novák ◽

Aaron M Rashotte

Keyword(s):

Oxidative Stress ◽

Transcription Factors ◽

Stress Response ◽

Stress Responses ◽

Oxidative Stress Response ◽

Response Factors ◽

Ontology Term ◽

Regulated Expression ◽

Cytokinin Response ◽

Oxidative Stress Responses

Abstract Cytokinin response factors (CRFs) are transcription factors that are involved in cytokinin (CK) response, as well as being linked to abiotic stress tolerance. In particular, oxidative stress responses are activated by Clade III CRF members, such as AtCRF6. Here we explored the relationships between Clade III CRFs and oxidative stress. Transcriptomic responses to oxidative stress were determined in two Clade III transcription factors, Arabidopsis AtCRF5 and tomato SlCRF5. AtCRF5 was required for regulated expression of >240 genes that are involved in oxidative stress response. Similarly, SlCRF5 was involved in the regulated expression of nearly 420 oxidative stress response genes. Similarities in gene regulation by these Clade III members in response to oxidative stress were observed between Arabidopsis and tomato, as indicated by Gene Ontology term enrichment. CK levels were also changed in response to oxidative stress in both species. These changes were regulated by Clade III CRFs. Taken together, these findings suggest that Clade III CRFs play a role in oxidative stress response as well as having roles in CK signaling.

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