scholarly journals Freezing Tolerance of Lolium multiflorum/Festuca arundinacea Introgression Forms is Associated with the High Activity of Antioxidant System and Adjustment of Photosynthetic Activity under Cold Acclimation

2020 ◽  
Vol 21 (16) ◽  
pp. 5899 ◽  
Author(s):  
Adam Augustyniak ◽  
Izabela Pawłowicz ◽  
Katarzyna Lechowicz ◽  
Karolina Izbiańska-Jankowska ◽  
Magdalena Arasimowicz-Jelonek ◽  
...  

Though winter-hardiness is a complex trait, freezing tolerance was proved to be its main component. Species from temperate regions acquire tolerance to freezing in a process of cold acclimation, which is associated with the exposure of plants to low but non-freezing temperatures. However, mechanisms of cold acclimation in Lolium-Festuca grasses, important for forage production in Europe, have not been fully recognized. Thus, two L. multiflorum/F. arundinacea introgression forms with distinct freezing tolerance were used herein as models in the comprehensive research to dissect these mechanisms in that group of plants. The work was focused on: (i) analysis of cellular membranes’ integrity; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gas exchange; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); (iii) analysis of plant antioxidant capacity (reactive oxygen species generation; gene expression, protein accumulation, and activity of selected enzymes); and (iv) analysis of Cor14b accumulation, under cold acclimation. The more freezing tolerant introgression form revealed a higher integrity of membranes, an ability to cold acclimate its photosynthetic apparatus and higher water use efficiency after three weeks of cold acclimation, as well as a higher capacity of the antioxidant system and a lower content of reactive oxygen species in low temperature.

2000 ◽  
Vol 279 (2) ◽  
pp. L302-L311 ◽  
Author(s):  
Andrea L. True ◽  
Arshad Rahman ◽  
Asrar B. Malik

Reactive oxygen species have been proposed to signal the activation of the transcription factor nuclear factor (NF)-κB in response to tumor necrosis factor (TNF)-α challenge. In the present study, we investigated the effects of H2O2 and TNF-α in mediating activation of NF-κB and transcription of the intercellular adhesion molecule (ICAM)-1 gene. Northern blot analysis showed that TNF-α exposure of human dermal microvascular endothelial cells (HMEC-1) induced marked increases in ICAM-1 mRNA and cell surface protein expression. In contrast, H2O2 added at subcytolytic concentrations failed to activate ICAM-1 expression. Challenge with H2O2 also failed to induce NF-κB-driven reporter gene expression in the transduced HMEC-1 cells, whereas TNF-α increased the NF-κB-driven gene expression ∼10-fold. Gel supershift assay revealed the presence of p65 (Rel A), p50, and c-Rel in both H2O2- and TNF-α-induced NF-κB complexes bound to the ICAM-1 promoter, with the binding of the p65 subunit being the most prominent. In vivo phosphorylation studies, however, showed that TNF-α exposure induced marked phosphorylation of NF-κB p65 in HMEC-1 cells, whereas H2O2 had no effect. These results suggest that reactive oxygen species generation in endothelial cells mediates the binding of NF-κB to nuclear DNA, whereas TNF-α generates additional signals that induce phosphorylation of the bound NF-κB p65 and confer transcriptional competency to NF-κB.


2002 ◽  
Vol 33 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Stephen D. Hursting ◽  
Jian-cheng Shen ◽  
Xiao-Ya Sun ◽  
Thomas T.Y. Wang ◽  
James M. Phang ◽  
...  

2020 ◽  
Vol 21 (3) ◽  
pp. 728 ◽  
Author(s):  
Abdul Wakeel ◽  
Ming Xu ◽  
Yinbo Gan

Chromium (Cr) is one of the top seven toxic heavy metals, being ranked 21st among the abundantly found metals in the earth’s crust. A huge amount of Cr releases from various industries and Cr mines, which is accumulating in the agricultural land, is significantly reducing the crop development, growth, and yield. Chromium mediates phytotoxicity either by direct interaction with different plant parts and metabolic pathways or it generates internal stress by inducing the accumulation of reactive oxygen species (ROS). Thus, the role of Cr-induced ROS in the phytotoxicity is very important. In the current study, we reviewed the most recent publications regarding Cr-induced ROS, Cr-induced alteration in the enzymatic antioxidant system, Cr-induced lipid peroxidation and cell membrane damage, Cr-induced DNA damage and genotoxicity, Cr-induced ultrastructural changes in cell and subcellular level, and Cr-induced alterations in photosynthesis and photosynthetic apparatus. Taken together, we conclude that Cr-induced ROS and the suppression of the enzymatic antioxidant system actually mediate Cr-induced cytotoxic, genotoxic, ultrastructural, and photosynthetic changes in plants.


The eff ect of the non-opiate analog of leu-enkephalin (peptide NALE: Phe – D – Ala – Gly – Phe – Leu – Arg) on the reactive oxygen species generation in the heart of albino rats in the early postnatal period was studied. Peptide NALE was administered intraperitoneally in the dose of 100 μ/kg daily from 2 to 6 days of life. Reactive oxygen species generation was assessed by chemiluminescence in the heart homogenates of 7-day-old animals. Decreasing of reactive oxygen species generation nearly by 30 % and an increasing in antioxidant system activity by the 20-27 %, compared with the control parameters, were found. The antioxidant eff ect of peptide NALE is associated with the presence of the amino acid Arg in the structure of the peptide. An analogue of NALE peptide, devoid of Arg (peptide Phe – D – Ala – Gly – Phe – Leu – Gly), had a signifi cant lower antioxidant eff ect. The NO-synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in the dose 50 mg/kg, administered with NALE peptide, reduced the severity of the NALE antioxidant eff ect. The results of the study suggest that the pronounced antioxidant eff ect of NALE peptide in the heart of albino rats, at least in part, is due to the interaction with the nitric oxide system.


1993 ◽  
Vol 149 (1) ◽  
pp. 64-67 ◽  
Author(s):  
Donald L. Weese ◽  
Michael L. Peaster ◽  
Kyle K. Himsl ◽  
Gary E. Leach ◽  
Pramod M. Lad ◽  
...  

2020 ◽  
Vol 21 (14) ◽  
pp. 4970
Author(s):  
Juan Perdomo ◽  
Carlos Quintana ◽  
Ignacio González ◽  
Inmaculada Hernández ◽  
Sara Rubio ◽  
...  

Melatonin is present in all living organisms where it displays a diversity of physiological functions. Attenuation of melanogenesis by melatonin has been reported in some mammals and also in rodent melanoma cells. However, melatonin may also stimulate melanogenesis in human melanoma cells through mechanisms that have not yet been revealed. Using the human melanoma cells SK-MEL-1 as a model, an increase in both tyrosinase activity and melanin was already observed at 24 h after melatonin treatment with maximal levels of both being detected at 72 h. This effect was associated with the induction in the expression of the enzymes involved in the synthesis of melanin. In this scenario, glycogen synthase kinase-3β seems to play a significant function since melatonin decreased its phosphorylation and preincubation with specific inhibitors of this protein kinase (lithium or BIO) reduced the expression and activity of tyrosinase. Blocking of PI3K/AKT pathway stimulated melanogenesis and the effect was suppressed by the inhibitors of glycogen synthase kinase-3β. Although melatonin is a recognized antioxidant, we found that it stimulates reactive oxygen species generation in SK-MEL-1 cells. These chemical species seem to be an important signal in activating the melanogenic process since the antioxidants N-acetyl-l-cysteine and glutathione decreased both the level and activity of tyrosinase stimulated by melatonin. Our results support the view that regulation of melanogenesis involves a cross-talk between several signaling pathways.


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