scholarly journals Affinity of class I and class III peroxidases for H2O2 in pepper leaves of different maturity

2021 ◽  
pp. 73-85
Author(s):  
Tanja Trifković ◽  
Dino Hasanagić ◽  
Biljana Kukavica

Paper deals with activities of Class III peroxidases (POX, EC 1.11.1.7) and Class I peroxidases (ascorbate peroxidase, APX, EC 1.11.1.11) as well as the Km of these enzymes for hydrogen peroxide (H2O2) in the pepper leaves of different maturity. The obtained results suggest that the youngest pepper leaves compared to more mature ones have different strategies for H2O2 removal. There was an increase in APX activity with leaf maturity, while POX activity had the opposite trend, and its lowest activity was observed in the oldest leaves. The accumulation of reducing substrates i.e., ascorbate and total phenols was in positive correlation with corresponding enzymes following leaf maturity. The comparison of POX and APX affinity for H2O2 in pepper leaves of different maturity and their relationship between these enzymes' activities were showed.

2004 ◽  
Vol 279 (37) ◽  
pp. 39000-39009 ◽  
Author(s):  
Roberta Pierattelli ◽  
Lucia Banci ◽  
Nigel A. J. Eady ◽  
Jacques Bodiguel ◽  
Jamie N. Jones ◽  
...  

2019 ◽  
Vol 71 (1) ◽  
pp. 219-233 ◽  
Author(s):  
Xue Xia ◽  
Hui-Ming Zhang ◽  
Christina E Offler ◽  
John W Patrick

Abstract Transfer cells are characterized by an amplified plasma membrane area supported on a wall labyrinth composed of a uniform wall layer (UWL) from which wall ingrowth (WI) papillae arise. Adaxial epidermal cells of developing Vicia faba cotyledons, when placed in culture, undergo a rapid (hours) trans-differentiation to a functional epidermal transfer cell (ETC) phenotype. The trans-differentiation event is controlled by a signalling cascade comprising auxin, ethylene, apoplasmic reactive oxygen species (apoROS), and cytosolic Ca2+. Apoplasmic hydrogen peroxide (apoH2O2) was confirmed as the apoROS regulating UWL and WI papillae formation. Informed by an ETC-specific transcriptome, a pharmacological approach identified a temporally changing cohort of H2O2 biosynthetic enzymes. The cohort contained a respiratory burst oxidase homologue, polyamine oxidase, copper amine oxidase, and a suite of class III peroxidases. Collectively these generated two consecutive bursts in apoH2O2 production. Spatial organization of biosynthetic/catabolic enzymes was deduced from responses to pharmacologically blocking their activities on the cellular and subcellular distribution of apoH2O2. The findings were consistent with catalase activity constraining the apoH2O2 signal to the outer periclinal wall of the ETCs. Strategic positioning of class III peroxidases in this outer domain shaped subcellular apoH2O2 signatures that differed during assembly of the UWL and WI papillae.


1995 ◽  
Vol 60 (9) ◽  
pp. 1502-1528 ◽  
Author(s):  
Oldřich Pytela

Alternative interpretation of substituent effects (AISE) starts from the presumption that a substituent only possesses a single property described by a single substituent constant. This property is transmitted to the reaction centre by three different ways depending on the interaction type in the triad reaction centre - basic skeleton - substituent. For interpretation it is substantial whether or not the substituent has p electrons at the atom adjacent to the basic skeleton. If it has none, the substituent belongs to class I and operates only by its basic effect described by the mentioned single substituent constant. Substituents of class II possess a free electron pair at the atom adjacent to the basic skeleton, and those of class III have a multiple bond between the first and the second atoms which is polarized in the direction from the basic skeleton. Substituent effects in class I are described by a substituent constant identical with σI constant. Substituents in classes II and III show additional effects proportional to the same constant. Hence, a separate treatment of substituent effects in the individual classes provides three straight lines intersecting in a common point. Mathematically, the description of substituent effects in this approach is expressed by a family of lines with a single explaining variable. The point of intersection, which is referred to as the iso-effect point, is not identical with the classic standard substituent - hydrogen - but is near to CN substituent. The approach given has the advantage of adopting a single substituent constant whose scale can be adjusted relatively precisely. Its drawback (like in the case of the correlation equations derived from the principle of separation of substituent effects) lies in a more extensive set of substituents needed for a correlation. The AISE principle has been applied to 318 series of experimental data describing effects of 32 substituents in a large variety of chemical models (aliphatic, alicyclic, aromatic, heteroaromatic, with or without direct conjugation between reaction centre and substituent) in both chemical reactions and equilibria. A comparison with two other correlation relations with two and three substituent constants for interpretation of substituent effects based on the principle of separation of the individual substituent effects showed that the closeness of AISE based correlations is comparable with that of the correlation equations currently used. It was somewhat less successful in the models with direct conjugation between reaction centre and substituent but the AISE principle can be used even in these cases.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1349
Author(s):  
Ahlam Khalofah ◽  
Mona Kilany ◽  
Hussein Migdadi

Heavy metals are primarily generated and deposited in the environment, causing phytotoxicity. This work evaluated fenugreek plants’ morpho-physiological and biochemical responses under mercury stress conditions toward Ag nanoparticles and Sphingobacterium ginsenosidiumtans applications. The fabrication of Ag nanoparticles by Thymus vulgaris was monitored and described by UV/Vis analysis, FTIR, and SEM. The effect of mercury on vegetative growth was determined by measuring the root and shoots length, the number and area of leaves, the relative water content, and the weight of the green and dried plants; appraisal of photosynthetic pigments, proline, hydrogen peroxide, and total phenols content were also performed. In addition, the manipulation of Ag nanoparticles, S. ginsenosidiumtans, and their combination were tested for mercury stress. Here, Ag nanoparticles were formed at 420 nm with a uniform cuboid form and size of 85 nm. Interestingly, the gradual suppression of vegetal growth and photosynthetic pigments by mercury, Ag nanoparticles, and S. ginsenosidiumtans were detected; however, carotenoids and anthocyanins were significantly increased. In addition, proline, hydrogen peroxide, and total phenols content were significantly increased because mercury and S. ginsenosidiumtans enhance this increase. Ag nanoparticles achieve higher levels by the combination. Thus, S. ginsenosidiumtans and Ag nanoparticles could have the plausible ability to relieve and combat mercury’s dangerous effects in fenugreek.


Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 413
Author(s):  
Hui-Ling Chen ◽  
Jason Chen-Chieh Fang ◽  
Chia-Jung Chang ◽  
Ti-Feng Wu ◽  
I-Kuan Wang ◽  
...  

Background. Previous studies have shown that environmental cadmium exposure could disrupt salivary gland function and is associated with dental caries and reduced bone density. Therefore, this cross-sectional study attempted to determine whether tooth decay with tooth loss following cadmium exposure is associated with some dental or skeletal traits such as malocclusions, sagittal skeletal pattern, and tooth decay. Methods. Between August 2019 and June 2020, 60 orthodontic patients with no history of previous orthodontics, functional appliances, or surgical treatment were examined. The patients were stratified into two groups according to their urine cadmium concentrations: high (>1.06 µg/g creatinine, n = 28) or low (<1.06 µg/g creatinine, n = 32). Results. The patients were 25.07 ± 4.33 years old, and most were female (female/male: 51/9 or 85%). The skeletal relationship was mainly Class I (48.3%), followed by Class II (35.0%) and Class III (16.7%). Class I molar relationships were found in 46.7% of these patients, Class II molar relationships were found in 15%, and Class III molar relationships were found in 38.3%. The mean decayed, missing, and filled surface (DMFS) score was 8.05 ± 5.54, including 2.03 ± 3.11 for the decayed index, 0.58 ± 1.17 for the missing index, and 5.52 ± 3.92 for the filled index. The mean index of complexity outcome and need (ICON) score was 53.35 ± 9.01. The facial patterns of these patients were within the average low margin (26.65 ± 5.53 for Frankfort–mandibular plane angle (FMA)). There were no significant differences in the above-mentioned dental indices between patients with high urine cadmium concentrations and those with low urine cadmium concentrations. Patients were further stratified into low (<27, n = 34), average (27–34, n = 23), and high (>34, n = 3) FMA groups. There were no statistically significant differences in the urine cadmium concentration among the three groups. Nevertheless, a marginally significant p-value of 0.05 for urine cadmium concentration was noted between patients with low FMA and patients with high FMA. Conclusion. This analysis found no association between environmental cadmium exposure and dental indices in our orthodontic patients.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kewei Cai ◽  
Huixin Liu ◽  
Song Chen ◽  
Yi Liu ◽  
Xiyang Zhao ◽  
...  

Abstract Background Class III peroxidases (POD) proteins are widely present in the plant kingdom that are involved in a broad range of physiological processes including stress responses and lignin polymerization throughout the plant life cycle. At present, POD genes have been studied in Arabidopsis, rice, poplar, maize and Chinese pear, but there are no reports on the identification and function of POD gene family in Betula pendula. Results We identified 90 nonredundant POD genes in Betula pendula. (designated BpPODs). According to phylogenetic relationships, these POD genes were classified into 12 groups. The BpPODs are distributed in different numbers on the 14 chromosomes, and some BpPODs were located sequentially in tandem on chromosomes. In addition, we analyzed the conserved domains of BpPOD proteins and found that they contain highly conserved motifs. We also investigated their expression patterns in different tissues, the results showed that some BpPODs might play an important role in xylem, leaf, root and flower. Furthermore, under low temperature conditions, some BpPODs showed different expression patterns at different times. Conclusions The research on the structure and function of the POD genes in Betula pendula plays a very important role in understanding the growth and development process and the molecular mechanism of stress resistance. These results lay the theoretical foundation for the genetic improvement of Betula pendula.


2000 ◽  
Vol 348 (2) ◽  
pp. 321 ◽  
Author(s):  
Alexander N.P. HINER ◽  
José Neptuno RODRÍGUEZ-LÓPEZ ◽  
Marino B. ARNAO ◽  
Emma LLOYD RAVEN ◽  
Francisco GARCÍA-CÁNOVAS ◽  
...  

Neurosurgery ◽  
2017 ◽  
Vol 82 (5) ◽  
pp. 695-700 ◽  
Author(s):  
Anil K Roy ◽  
Brian M Howard ◽  
Diogo C Haussen ◽  
Joshua W Osbun ◽  
Sameer H Halani ◽  
...  

Abstract BACKGROUND Aneurysms at the origin of the posterior communicating artery (PcommA) have been demonstrated to be effectively treated with the pipeline embolization device (PED). Much less is known about the efficacy of the PED for aneurysms associated with a fetal posterior cerebral artery (fPCA) variant. OBJECTIVE To study PED treatment efficacy of PcommA aneurysms, including fPCA aneurysms. METHODS A prospectively maintained university database of aneurysm patients treated with the PED was retrospectively reviewed. Demographics, treatment details, and imaging were reviewed for all PcommA and fPCA aneurysms. RESULTS Out of a total of 285 patients treated with PED, 50 patients (mean age 57.5 ± 12.2 yr, 42 females) with unruptured PcommA (9 fPCA) aneurysms were identified. Mean follow-up duration was 14.0 ± 11.6 mo (48 patients). Roy-Raymond class I occlusion on follow-up magnetic resonance or catheter angiography (mean time 11.7 ± 6.8 mo) was achieved in 30 patients (62.5%), class II occlusion in 11 patients (22.9%) and class III occlusion in 7 patients (14.5%). The PcommA was occluded in 56% of patients without any clinical symptoms. No deaths or permanent neurological complications occurred. In fPCA aneurysms, class I occlusion was seen in 1 patient, class 2 occlusion in 2 patients, and class III occlusion in 6 patients. Multivariate analysis revealed an independent association between incomplete occlusion and fPCA configuration (OR 73.65; 95% CI: 5.84-929.13; P = .001). CONCLUSION The PED is a safe and effective treatment for PcommA aneurysms, although fetal anatomy should increase consideration of traditional endovascular techniques or surgical clipping.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Kochav ◽  
R.C Chen ◽  
J.M.D Dizon ◽  
J.A.R Reiffel

Abstract Background Theoretical concern exists regarding AV block (AVB) with class I antiarrhythmics (AADs) when bundle branch block (BBB) is present. Whether this is substantiated in real-world populations is unknown. Purpose To determine the relationship between type of AAD and incidence of AVB in patients with preexisting BBB. Methods We retrospectively studied all patients with BBB who received class I and III AADs between 1997–2019 to compare incidence of AVB. We defined index time as first exposure to either drug class and excluded patients with prior AVB or exposed to both classes. Time-at-risk window ended at first outcome occurrence or when patients were no longer observed in the database. We estimated hazard ratios for incident AVB using Cox proportional hazards models with propensity score stratification, adjusting for over 32,000 covariates from the electronic health record. Kaplan-Meier methods were used to determine treatment effects over time. Results Of 40,120 individuals with BBB, 148 were exposed to a class I AAD and 2401 to a class III AAD. Over nearly 4,200 person-years of follow up, there were 22 and 620 outcome events in the class I and class III cohorts, respectively (Figure). In adjusted analyses, AVB risk was markedly lower in patients exposed to class I AADs compared with class III (HR 0.48 [95% CI 0.30–0.75]). Conclusion Among patients with BBB, exposure to class III AADs was strongly associated with greater risk of incident AVB. This likely reflects differences in natural history of patients receiving class I vs class III AADs rather than adverse class III effects, however, the lack of worse outcomes acutely with class I AADs suggests that they may be safer in BBB than suspected. Funding Acknowledgement Type of funding source: None


Genetics ◽  
1972 ◽  
Vol 72 (3) ◽  
pp. 431-439
Author(s):  
E C Travaglini ◽  
J Petrovic ◽  
J Schultz

ABSTRACT A tentative evolutionary pattern has been found for two classes of the multiple satellite DNA's found in the genus Drosophila. The satellite DNA's from five Drosophila species (D. melanogaster, D. simulans, D. nasuta, D. virilis and D. hydei) were analyzed and found to fall into three arbitrary CsCl buoyant density classes: Class I, ρ = 1.661-1.669 g cm-3, DNA molecules composed of primarily dA and dT moieties; Class II, ρ = 1.685 and ρ = 1.692, DNA molecules of low GC content; and Class III, ρ = 1.711, a DNA of high GC composition. The dAT satellite DNA's appear in all the species studied except D. hydei, the species of most recent evolutionary divergence, whereas the heavy satellite appears only in the two species of most recent divergence, D. virilis and D. hydei.


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