Time-series responses in photosynthetic activity, 2-cysteine peroxiredoxin gene expression, and proteomics of Chattonella marina var. antiqua under different oxidative stress

Harmful Algae ◽  
2020 ◽  
Vol 94 ◽  
pp. 101808 ◽  
Author(s):  
Xuchun Qiu ◽  
Chen Chen ◽  
Yohei Shimasaki ◽  
Koki Mukai ◽  
Ayano Teramoto ◽  
...  
2019 ◽  
Author(s):  
Yuan Fang ◽  
Haoye Wang ◽  
Xia Liu ◽  
Yuchun Rao ◽  
Xin Dedong ◽  
...  

AbstractXanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of bacterial leaf streak in rice. It is known as one of the most severe seed-born bacterial diseases of rice, molecular role governing its interaction with rice is mostly still unexplored. To successfully invade rice, the survival of the Xoc is mandotarory following generating a specific response to its host’s oxidative stress condition. However, the response network of Xoc is still unknown. To address this question, we performed a time-series RNA-seq analysis on the Xoc response to H2O2. Overall, our RNA sequence analysis of Xoc revealed a significant global gene expression profile when it exposed to H2O2. The response of key genes was also noted that soxR triggers and regulates the Xoc oxidative stress response in the early stage of infection, gene expression kinetics among the time-series samples, namely for TonB-dependent receptors and the suf and pst operons. Moreover, a hypothetical protein (XOC_2868) showed significant differential expression following its mutant endorsed RNA-seq findings by clearly displaying a greater H2O2 sensitivity and decreased pathogenicity than the wild-type. Gene location and phylogeny analysis strongly suggests that this gene may have been horizontally transferred from a Burkholderiaceae ancestor. Our study not only provides a first glance of Xoc’s global response against oxidative stress, but it also reveals the impact of horizontal gene transfer in the evolutionary history of Xoc.


2020 ◽  
Vol 17 (3) ◽  
pp. 191-199
Author(s):  
Seval Yilmaz ◽  
Fatih Mehmet Kandemir ◽  
Emre Kaya ◽  
Mustafa Ozkaraca

Objective: This study aimed to detect hepatic oxidative damage caused by aflatoxin B1 (AFB1), as well as to examine how propolis protects against hepatotoxic effects of AFB1. Method: Rats were split into four groups as control group, AFB1 group, propolis group, AFB1+ propolis group. Results: There was significant increase in malondialdehyde (MDA) level and tumor suppressor protein (TP53) gene expression, Glutathione (GSH) level, Catalase (CAT) activity, CAT gene expression decreased in AFB1 group in blood. MDA level and Glutathione-S-Transferase (GST) activity, GST and TP53 gene expressions increased in AFB1 group, whereas GSH level and CAT activity alongside CAT gene expression decreased in liver. AFB1+propolis group showed significant decrease in MDA level, GST activity, TP53 and GST gene expressions, GSH level and CAT activity and CAT gene expression increased in liver compared to AFB1 group. Conclusion: These results suggest that propolis may potentially be natural agent that prevents AFB1- induced oxidative stress and hepatotoxicity.


2006 ◽  
Vol 339 (2) ◽  
pp. 624-632 ◽  
Author(s):  
Mitsunori Kamigaki ◽  
Shinji Sakaue ◽  
Ichizo Tsujino ◽  
Hiroshi Ohira ◽  
Daisuke Ikeda ◽  
...  

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A38-A38
Author(s):  
Shilpa Ravindran ◽  
Heba Sidahmed ◽  
Harshitha Manjunath ◽  
Rebecca Mathew ◽  
Tanwir Habib ◽  
...  

BackgroundPatients with inflammatory bowel disease (IBD) have increased risk of developing colorectal cancer (CRC), depending on the duration and severity of the disease. The evolutionary process in IBD is driven by chronic inflammation leading to epithelial-to-mesenchymal transition (EMT) events in colonic fibrotic areas. EMT plays a determinant role in tumor formation and progression, through the acquisition of ‘stemness’ properties and the generation of neoplastic cells. The aim of this study is to monitor EMT/cancer initiating tracts in IBD in association with the deep characterization of inflammation in order to assess the mechanisms of IBD severity and progression towards malignancy.Methods10 pediatric and 20 adult IBD patients, admitted at Sidra Medicine (SM) and Hamad Medical Corporation (HMC) respectively, have been enrolled in this study, from whom gut tissue biopsies (from both left and right side) were collected. Retrospectively collected tissues (N=10) from patients with malignancy and history of IBD were included in the study. DNA and RNA were extracted from fresh small size (2–4 mm in diameter) gut tissues using the BioMasher II (Kimble) and All Prep DNA/RNA kits (Qiagen). MicroRNA (miRNA; N=700) and gene expression (N=800) profiling have been performed (cCounter platform; Nanostring) as well as the methylation profiling microarray (Infinium Methylation Epic Bead Chip kit, Illumina) to interrogate up to 850,000 methylation sites across the genome.ResultsDifferential miRNA profile (N=27 miRNA; p<0.05) was found by the comparison of tissues from pediatric and adult patients. These miRNAs regulate: i. oxidative stress damage (e.g., miR 99b), ii. hypoxia induced autophagy; iii. genes associated with the susceptibility to IBD (ATG16L1, NOD2, IRGM), iv. immune responses, such as TH17 T cell subset (miR 29). N=6 miRNAs (miR135b, 10a196b, 125b, let7c, 375) linked with the regulation of Wnt/b-catenin, EM-transaction, autophagy, oxidative stress and play role also in cell proliferation and mobilization and colorectal cancer development were differentially expressed (p<0.05) in tissues from left and right sides of gut. Gene expression signature, including genes associated with inflammation, stemness and fibrosis, has also been performed for the IBD tissues mentioned above. Methylation sites at single nucleotide resolution have been analyzed.ConclusionsAlthough the results warrant further investigation, differential genomic profiling suggestive of altered pathways involved in oxidative stress, EMT, and of the possible stemness signature was found. The integration of data from multiple platforms will provide insights of the overall molecular determinants in IBD patients along with the evolution of the disease.Ethics ApprovalThis study was approved by Sidra Medicine and Hamad Medical Corporation Ethics Boards; approval number 180402817 and MRC-02-18-096, respectively.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 465
Author(s):  
Hesham F. Alharby ◽  
Hassan S. Al-Zahrani ◽  
Khalid R. Hakeem ◽  
Hameed Alsamadany ◽  
El-Sayed M. Desoky ◽  
...  

For maize, the potential preventive role of foliar spraying with an extract derived from maize grain (MEg, 2%), silymarin (Sm, 0.5 mM), or silymarin-enriched MEg (MEg-Sm) in attenuating the stress effects of cadmium (Cd, 0.5 mM) was examined using a completely randomized design layout. Under normal conditions, foliar spraying with MEg, Sm, or MEg-Sm was beneficial (with MEg-Sm preferred) for maize plants, whereas the benefit was more pronounced under Cd stress. The use of Cd through irrigation water decreased plant growth traits, photosynthetic efficiency, including instantaneous carboxylation efficiency, Fv/Fm, and pigment contents, and hormonal contents (e.g., auxin, gibberellins, cytokinins including trans-zeatin, and salicylic acid). These undesired findings were due to an increase in Cd content, leading to increased levels of oxidative stress (O2•− and H2O2), ionic leakage, and lipid peroxidation. Therefore, this damage resulted in an increase in the activities of nonenzymatic antioxidants, Sm, antioxidative enzymes, and enzyme gene expression. However, under Cd stress, although foliar spray with MEg or Sm had better findings than control, MEg-Sm had better findings than MEg or Sm. Application of MEg-Sm greatly increased photosynthesis efficiency, restored hormonal homeostasis, and further increased the activities of various antioxidants, Sm, antioxidative enzymes, and enzyme gene expression. These desired findings were due to the suppression of the Cd content, and thus the levels of O2•−, H2O2, ionic leakage, and lipid peroxidation, which were positively reflected in the growth and accumulation of dry matter in maize plants. The data obtained in this study recommend applying silymarin-enriched maize grain extract (MEg-Sm at 0.24 g Sm L−1 of MEg) as a spray solution to maize plants when exposed to excess Cd in soil or irrigation water.


Author(s):  
Huaming He ◽  
Jordi Denecker ◽  
Katrien Van Der Kelen ◽  
Patrick Willems ◽  
Robin Pottie ◽  
...  

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.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 162
Author(s):  
Yohei Shimasaki ◽  
Koki Mukai ◽  
Yuki Takai ◽  
Xuchun Qiu ◽  
Yuji Oshima

Peroxiredoxin (Prx) is a relatively recently discovered antioxidant enzyme family that scavenges peroxides and is known to be present in organisms from biological taxa ranging from bacteria to multicellular eukaryotes, including photosynthetic organisms. Although there have been many studies of the Prx family in higher plants, green algae, and cyanobacteria, few studies have concerned raphidophytes and dinoflagellates, which are among the eukaryotic algae that cause harmful algal blooms (HABs). In our proteomic study using 2-D electrophoresis, we found a highly expressed 2-Cys peroxiredoxin (2-CysPrx) in the raphidophyte Chattonella marina var. antiqua, a species that induces mass mortality of aquacultured fish. The abundance of the C. marina 2-CysPrx enzyme was highest in the exponential growth phase, during which photosynthetic activity was high, and it then decreased by about a factor of two during the late stationary growth phase. This pattern suggested that 2-CysPrx is a key enzyme involved in the maintenance of high photosynthesis activity. In addition, the fact that the depression of photosynthesis by excessively high irradiance was more severe in the 2-CysPrx low-expression strain (wild type) than in the normal-expression strain (wild type) of C. marina suggested that 2-CysPrx played a critical role in protecting the cell from oxidative stress caused by exposure to excessively high irradiance. In the field of HAB research, estimates of growth potential have been desired to predict the population dynamics of HABs for mitigating damage to fisheries. Therefore, omics approaches have recently begun to be applied to elucidate the physiology of the growth of HAB species. In this review, we describe the progress we have made using a molecular physiological approach to identify the roles of 2-CysPrx and other antioxidant enzymes in mitigating environmental stress associated with strong light and high temperatures and resultant oxidative stress. We also describe results of a survey of expressed Prx genes and their growth-phase-dependent behavior in C. marina using RNA-seq analysis. Finally, we speculate about the function of these genes and the ecological significance of 2-CysPrx, such as its involvement in circadian rhythms and the toxicity of C. marina to fish.


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