scholarly journals A mechanism coordinating root elongation, endodermal differentiation, redox homeostasis and response

2019 ◽  
Author(s):  
Jing Fu ◽  
Jiaming Liu ◽  
Xudong Gao ◽  
Xinglin Zhang ◽  
Juan Bai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Root Growth ◽  
Cell Elongation ◽  
Growth Regulation ◽  
Redox Homeostasis ◽  
Oxidative Stress Response ◽  
Radial Patterning ◽  
Endodermal Differentiation

AbstractRoot growth relies on both cell division and elongation, which occur in the meristem and elongation zones respectively. SCARECROW (SCR) is a GRAS family gene essential for root growth and radial patterning in the Arabidopsis root. Previous studies showed that SCR promotes root growth by suppressing cytokinin response in the meristem, but there is also evidence that SCR expressed beyond the meristem is required as well for root growth. Here we report that SCR promotes root growth by promoting cell elongation through suppression of oxidative stress response and maintenance of redox homeostasis in the elongation zone. In the scr root, a higher level of hydrogen peroxide was detected, which can be attributed to down-regulation of peroxidase gene 3. When stress response was blocked or redox status was ameliorated by the aba2 or upb1 mutation, the scr mutant produced a significantly longer root with longer cells and a larger and mitotically more active meristem, even though the stem cell and radial patterning defects still persisted. We showed that WRKY15, an oxidative responsive gene, was a direct target of SCR down-regulated in the scr mutant, which suggests that SCR has an active role in suppressing oxidative stress response. Since hydrogen peroxide and peroxidases are essential for endodermal differentiation, these results suggest that SCR plays a central role in coordinating cell elongation, endodermal differentiation, redox homeostasis, and oxidative stress response in plant root.One sentence summaryThis study reveals a novel mechanism of root growth regulation, which involves a previously unrecognized role of SCR in regulating cell elongation, endodermal differentiation, and redox homeostasis.

TheahpDgene ofCorynebacterium glutamicumplays an important role in hydrogen peroxide-induced oxidative stress response

2018 ◽  
Vol 165 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Eun-Ji Hong ◽  
Haeri Jeong ◽  
Dong-Seok Lee ◽  
Younhee Kim ◽  
Heung-Shick Lee
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Oxidative Stress Response

scholarly journals Virulence of Streptococcus pneumoniae: PsaA Mutants Are Hypersensitive to Oxidative Stress

2002 ◽  
Vol 70 (3) ◽  
pp. 1635-1639 ◽  
Author(s):  
Hsing-Ju Tseng ◽  
Alastair G. McEwan ◽  
James C. Paton ◽  
Michael P. Jennings
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Pneumoniae ◽  
Stress Response ◽  
Nadh Oxidase ◽  
Redox Homeostasis ◽  
Oxidative Stress Response ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Altered Expression ◽  
Transport Complex

ABSTRACT psaA encodes a 37-kDa pneumococcal lipoprotein which is part of an ABC Mn(II) transport complex. Streptococcus pneumoniae D39 psaA mutants have previously been shown to be significantly less virulent than wild-type D39, but the mechanism underlying the attenuation has not been resolved. In this study, we have shown that psaA and psaD mutants are highly sensitive to oxidative stress, i.e., to superoxide and hydrogen peroxide, which might explain why they are less virulent than the wild-type strain. Our investigations revealed altered expression of the key oxidative-stress response enzymes superoxide dismutase and NADH oxidase in psaA and psaD mutants, suggesting that PsaA and PsaD may play important roles in the regulation of expression of oxidative-stress response enzymes and intracellular redox homeostasis.

scholarly journals Oxidative stress response ofInonotus obliquusinduced by hydrogen peroxide

2009 ◽  
Vol 47 (8) ◽  
pp. 814-823 ◽  
Author(s):  
Weifa Zheng ◽  
Yanxia Zhao ◽  
Meimei Zhang ◽  
Zhiwen Wei ◽  
Kangjie Miao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Oxidative Stress Response

scholarly journals Redox-Dependent Condensation Of the Mycobacterial Nucleoid By WhiB4

2017 ◽  
Author(s):  
Manbeena Chawla ◽  
Saurabh Mishra ◽  
Pankti Parikh ◽  
Mansi Mehta ◽  
Prashant Shukla ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Stress Response ◽  
Redox Homeostasis ◽  
Oxidative Stress Response ◽  
Chromosomal Structure ◽  
Redox Sensor ◽  
Intracellular Redox

AbstractOxidative stress response in bacteria is generally mediated through coordination between the regulators of oxidant-remediation systems (e.g.OxyR, SoxR) and nucleoid condensation (e.g.Dps, Fis). However, these genetic factors are either absent or rendered nonfunctional in the human pathogenMycobacterium tuberculosis(Mtb). Therefore, howMtborganizes genome architecture and regulates gene expression to counterbalance oxidative imbalance during infection is not known. Here, we report that an intracellular redox-sensor, WhiB4, dynamically links genome condensation and oxidative stress response inMtb. Disruption of WhiB4 affects the expression of genes involved in maintaining redox homeostasis, central carbon metabolism (CCM), respiration, cell wall biogenesis, DNA repair and protein quality control under oxidative stress. Notably, disulfide-linked oligomerization of WhiB4 in response to oxidative stress activates the protein’s ability to condense DNAin vitroandin vivo. Further, overexpression of WhiB4 led to hypercondensation of nucleoids, redox imbalance and increased susceptibility to oxidative stress, whereas WhiB4 disruption reversed this effect. In accordance with the findingsin vitro, ChIP-Seq data demonstrated non-specific binding of WhiB4 to GC-rich regions of theMtbgenome. Lastly, data indicate that WhiB4 deletion affected the expression of only a fraction of genes preferentially bound by the protein, suggesting its indirect effect on gene expression. We propose that WhiB4 is a novel redox-dependent nucleoid condensing protein that structurally couplesMtb’sresponse to oxidative stress with genome organization and transcription.Significance StatementMycobacterium tuberculosis (Mtb)needs to adapt in response to oxidative stress encountered inside human phagocytes. In other bacteria, condensation state of nucleoids modulates gene expression to coordinate oxidative stress response. However, this relation remains elusive inMtb. We performed molecular dissection of a mechanism controlled by an intracellular redox sensor, WhiB4, in organizing both chromosomal structure and selective expression of adaptive traits to counter oxidative stress inMtb. Using high-resolution sequencing, transcriptomics, imaging, and redox biosensor, we describe how WhiB4 modulates nucleoid condensation, global gene expression, and redox-homeostasis. WhiB4 over-expression hypercondensed nucleoids and perturbed redox homeostasis whereas WhiB4 disruption had an opposite effect. Our study discovered an empirical role for WhiB4 in integrating redox signals with nucleoid condensation inMtb.

Oxidative stress response of Inonotus obliquus induced by hydrogen peroxide

2009 ◽  
pp. 1-10 ◽  
Author(s):  
Weifa Zheng ◽  
Yanxia Zhao ◽  
Meimei Zhang ◽  
Zhiwen Wei ◽  
Kangjie Miao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Oxidative Stress Response ◽  
Inonotus Obliquus

scholarly journals Necessity of OxyR for the Hydrogen Peroxide Stress Response and Full Virulence in Ralstonia solanacearum

2011 ◽  
Vol 77 (18) ◽  
pp. 6426-6432 ◽  
Author(s):  
Zomary Flores-Cruz ◽  
Caitilyn Allen
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Mutant Strain ◽  
Ralstonia Solanacearum ◽  
Oxidative Stress Response ◽  
Ros Scavenging ◽  
Content Type ◽  
Peroxide Stress

ABSTRACTThe plant pathogenRalstonia solanacearum, which causes bacterial wilt disease, is exposed to reactive oxygen species (ROS) during tomato infection and expresses diverse oxidative stress response (OSR) genes during midstage disease on tomato. TheR. solanacearumgenome predicts that the bacterium produces multiple and redundant ROS-scavenging enzymes but only one known oxidative stress response regulator, OxyR. AnR. solanacearumoxyRmutant had no detectable catalase activity, did not grow in the presence of 250 μM hydrogen peroxide, and grew poorly in the oxidative environment of solid rich media. This phenotype was rescued by the addition of exogenous catalase, suggesting thatoxyRis essential for the hydrogen peroxide stress response. Unexpectedly, theoxyRmutant strain grew better than the wild type in the presence of the superoxide generator paraquat. Gene expression studies indicated thatkatE,kaG,ahpC1,grxC, andoxyRitself were each differentially expressed in theoxyRmutant background and in response to hydrogen peroxide, suggesting thatoxyRis necessary for hydrogen peroxide-inducible gene expression. Additional OSR genes were differentially regulated in response to hydrogen peroxide alone. The virulence of theoxyRmutant strain was significantly reduced in both tomato and tobacco host plants, demonstrating thatR. solanacearumis exposed to inhibitory concentrations of ROSin plantaand that OxyR-mediated responses to ROS during plant pathogenesis are important forR. solanacearumhost adaptation and virulence.

Oxidative stress response of filamentous fungi induced by hydrogen peroxide and paraquat

2005 ◽  
Vol 109 (2) ◽  
pp. 150-158 ◽  
Author(s):  
Maria B. Angelova ◽  
Svetlana B. Pashova ◽  
Boryana K. Spasova ◽  
Spassen V. Vassilev ◽  
Lyudmila S. Slokoska
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Filamentous Fungi ◽  
Oxidative Stress Response
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