Peroxidase: a multifunctional enzyme in grapevines

2003 ◽  
Vol 30 (6) ◽  
pp. 577 ◽  
Author(s):  
Alfonso Ros Barceló ◽  
Federico Pomar ◽  
Matías López-Serrano ◽  
Maria Angeles Pedreño
Keyword(s):  
Cell Wall ◽  
Metabolic Regulation ◽  
Trichoderma Viride ◽  
Visible Spectrum ◽  
H2o2 Production ◽  
Class Iii ◽  
Absorption Bands ◽  
Peroxidase Isoenzyme ◽  
Wide Range ◽  
Uv C

Peroxidases are heme-containing enzymes that catalyse the one-electron oxidation of several substrates at the expense of H2O2. They are probably encoded by a large multigene family in grapevines, and therefore show a high degree of polymorphism. Grapevine peroxidases are glycoproteins of high thermal stability, whose molecular weight usually ranges from 35 to 45 kDa. Their visible spectrum shows absorption bands characteristic of high-spin class III peroxidases. Grapevine peroxidases are capable of accepting a wide range of natural compounds as substrates, such as the cell wall protein extensin, plant growth regulators such as IAA, and phenolics such as benzoic acids, stilbenes, flavonols, cinnamyl alcohols and anthocyanins. They are located in cell walls and vacuoles. These locations are in accordance with their key role in determining the final cell wall architecture, especially regarding lignin deposition and extensin insolubilization, and the turnover of vacuolar phenolic metabolites, a task that also forms part of the molecular program of disease resistance. Although peroxidase is a constitutive enzyme in grapevines, its levels are strongly modulated during plant cell development and in response to both biotic and abiotic environmental factors. To gain an insight into the metabolic regulation of peroxidase, several authors have studied how grapevine peroxidase and H2O2 levels change in response to a changing environment. Nevertheless, the results obtained are not always easy to interpret. Despite such difficulties, the response of the peroxidase–H2O2 system to both UV-C radiation and Trichoderma viride elicitors is worthy of study. Both UV-C and T. viride elicitors induce specific changes in peroxidase isoenzyme / H2O2 levels, which result in specific changes in grapevine physiology and metabolism. In the case of T. viride-elicited grapevine cells, they show a particular mechanism for H2O2 production, in which NADPH oxidase-like activities are apparently not involved. However, they offer a unique system whereby the metabolic regulation of peroxidase by H2O2, with all its cross-talks and downstream signals, may be elegantly dissected.

Coniferyl alcohol oxidase activity of a cell-wall-located class III peroxidase

1999 ◽  
Vol 26 (5) ◽  
pp. 411 ◽  
Author(s):  
A. Ros Barceló ◽  
G. J. Aznar-Asensio
Keyword(s):  
Cell Wall ◽  
Oxidase Activity ◽  
Cell Walls ◽  
Alcohol Oxidase ◽  
Visible Spectrum ◽  
Coniferyl Alcohol ◽  
Class Iii ◽  
Apparent Homogeneity

Coniferyl alcohol oxidase activity was determined in cell walls from hypocotyls of the following species belonging to the family Asteraceae: Calendula officinalis, Callistephus sinensis, Cosmos bipinnanthus, Helianthus annuus, Helianthus debilis and Zinnia elegans. In all the cases studied, coniferyl alcohol oxidase activity was partially located ionically-bound to cell walls and resided in a basic peroxidase, the activity of which was stimulated by H 2 O 2 . This enzymatic activity was insensitive to freezing and was inactivated by high H 2 O 2 concentrations, as tested both in vitro and in situ by using purified cell wall fractions. The peroxidase with coniferyl alcohol oxidase activity was purified from Z. elegans hypocotyls until apparent homogeneity, as checked by SDS-PAGE. It showed a visible spectrum typical of a haem-containing high-spin ferric secretory (class III) plant peroxidase. Coniferyl alcohol oxidase activity of this basic peroxidase constitutes about 0.25% of the activity shown in the presence of H 2 O 2 . The significance of the coniferyl alcohol oxidase activity in vivo was studied in Z. elegans hypocotyls by means of histochemical tests, which revealed that it was located in the H 2 O 2 -producing lignifying xylem cells. The results obtained from the histochemical probes suggest that the coniferyl alcohol oxidase activity of this basic peroxidase is physiologically irrelevant in tissues that accumulate H 2 O 2 , as is the case of the lignifying xylem, where the peroxidase activity of the enzyme favorably competes with the oxidase activity of the enzyme.

scholarly journals Biotic and Abiotic Elicitors of Stilbenes Production in Vitis vinifera L. Cell Culture

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 490
Author(s):  
Martin Sák ◽  
Ivana Dokupilová ◽  
Šarlota Kaňuková ◽  
Michaela Mrkvová ◽  
Daniel Mihálik ◽  
...  
Keyword(s):  
Cell Wall ◽  
Vitis Vinifera ◽  
Cell Cultures ◽  
Trichoderma Viride ◽  
Vitis Vinifera L ◽  
Treated Plant ◽  
Abiotic Elicitors ◽  
In Vitro Cell Cultures ◽  
Red Grape

The in vitro cell cultures derived from the grapevine (Vitis vinifera L.) have been used for the production of stilbenes treated with different biotic and abiotic elicitors. The red-grape cultivar Váh has been elicited by natural cellulose from Trichoderma viride, the cell wall homogenate from Fusarium oxysporum and synthetic jasmonates. The sodium-orthovanadate, known as an inhibitor of hypersensitive necrotic response in treated plant cells able to enhance production and release of secondary metabolite into the cultivation medium, was used as an abiotic elicitor. Growth of cells and the content of phenolic compounds trans-resveratrol, trans-piceid, δ-viniferin, and ɛ-viniferin, were analyzed in grapevine cells treated by individual elicitors. The highest accumulation of analyzed individual stilbenes, except of trans-piceid has been observed after treatment with the cell wall homogenate from F. oxysporum. Maximum production of trans-resveratrol, δ- and ɛ-viniferins was triggered by treatment with cellulase from T. viride. The accumulation of trans-piceid in cell cultures elicited by this cellulase revealed exactly the opposite effect, with almost three times higher production of trans-resveratrol than that of trans-piceid. This study suggested that both used fungal elicitors can enhance production more effectively than commonly used jasmonates.

New insights on Laminaria digitata ultrastructure through combined conventional chemical fixation and cryofixation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christos Katsaros ◽  
Sophie Le Panse ◽  
Gillian Milne ◽  
Carl J. Carrano ◽  
Frithjof Christian Küpper
Keyword(s):  
Cell Wall ◽  
General Structure ◽  
Raw Material ◽  
Rocky Shores ◽  
Chemical Fixation ◽  
Laminaria Digitata ◽  
Vegetative Cells ◽  
Biological Studies ◽  
New Findings ◽  
Wide Range

Abstract The objective of the present study is to examine the fine structure of vegetative cells of Laminaria digitata using both chemical fixation and cryofixation. Laminaria digitata was chosen due to its importance as a model organism in a wide range of biological studies, as a keystone species on rocky shores of the North Atlantic, its use of iodide as a unique inorganic antioxidant, and its significance as a raw material for the production of alginate. Details of the fine structural features of vegetative cells are described, with particular emphasis on the differences between the two methods used, i.e. conventional chemical fixation and freeze-fixation. The general structure of the cells was similar to that already described, with minor differences between the different cell types. An intense activity of the Golgi system was found associated with the thick external cell wall, with large dictyosomes from which numerous vesicles and cisternae are released. An interesting type of cisternae was found in the cryofixed material, which was not visible with the chemical fixation. These are elongated structures, in sections appearing tubule-like, close to the external cell wall or to young internal walls. An increased number of these structures was observed near the plasmodesmata of the pit fields. They are similar to the “flat cisternae” found associated with the forming cytokinetic diaphragm of brown algae. Their possible role is discussed. The new findings of this work underline the importance of such combined studies which reveal new data not known until now using the old conventional methods. The main conclusion of the present study is that cryofixation is the method of choice for studying Laminaria cytology by transmission electron microscopy.

scholarly journals Co-operative action by endo- and exo-β-(1→3)-glucanases from parasitic fungi in the degradation of cell-wall glucans of Sclerotinia sclerotiorum (Lib.) de Bary

1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon
Keyword(s):  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Culture Filtrate ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Major Constituent ◽  
Coniothyrium Minitans ◽  
Parasitic Fungi ◽  
Complete Breakdown

1. Two fungi, Coniothyrium minitans Campbell and Trichoderma viride Pers. ex Fr., were grown on autoclaved crushed sclerotia of the species Sclerotinia sclerotiorum, which they parasitize. 2. in vitro the crude culture filtrates would lyse walls isolated from hyphal cells or the inner pseudoparenchymatous cells of the sclerotia, in which a branched β-(1→3)-β-(1→6)-glucan, sclerotan, is a major constituent. 3. Chromatographic fractionation of the enzymes in each culture filtrate revealed the presence of several laminarinases, the most active being an exo-β-(1→3)-glucanase, known from previous studies to attack sclerotan. Acting alone this brought about a limited degradation of the glucan, but the addition of fractions containing an endo-β-(1→3)-glucanase led to almost complete breakdown. A similar synergism between the two enzymes was found in their lytic action on cell walls. 4. When acting alone the endo-β-(1→3)-glucanase had a restricted action, the products including a trisaccharide, tentatively identified as 62-β-glucosyl-laminaribiose. 5. These results are discussed in relation to the structure of the cell walls and of their glucan constituents.

Congenital adrenal hyperplasia: molecular mechanisms resulting in 21-hydroxylase deficiency

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S315-S320 ◽  
Author(s):  
Patricia A. Donohoue ◽  
Cornelis Van Dop ◽  
Nicholas Jospe ◽  
Claude J. Migeon
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
Molecular Mechanisms ◽  
Sequence Data ◽  
Phenotypic Expression ◽  
Restriction Pattern ◽  
Class Iii ◽  
Adrenal Hyperplasia ◽  
Hydroxylase Deficiency ◽  
Wide Range ◽  
21 Hydroxylase Deficiency

Abstract 21-Hydroxylase deficiency resulting in congenital adrenal hyperplasia (CAH) is a HLA-linked autosomal recessive disorder that has a wide range of phenotypic expression. Two homologous 21-hydroxylase genes (21-OHA and 21-OHB) occur within the Class III region of the major histocompatibility complex, but only one (21-OHB) appears to function in adrenal steroidogenesis. Our restriction maps, and initial sequence data from White et al. (Pediatr Res 20:274A (1986)) for the two human 21-OH genes reveal a high degree of homology between these genes and a reading frame shift mutation in the 21-OHA gene respectively. Among fourteen control subjects, the intragenic restriction patterns of the 21-OHA and 21-OHB genes are invariant. The few restriction fragment length polymorphisms (RFLPs) found in some controls result from polymorphic restriction sites outside the 21-OH genes. In patients with CAH, several different mechanisms for mutation of the 21-OHB gene have been described: 1) deletion of the unique sequences of the 21-OHB gene, 2) conversion of the unique sequences of the 21-OHB gene to those of 21-OHA, and 3) mutations of 21-OHB which do not result in a detectable alteration of restriction pattern (e.g., point mutations). Duplication of the 21-OHA gene has been found in some patients with attenuated CAH; however, the significance of this finding remains unclear.

Spectrophotometry of Aqueous HNO3, H2SO4, and DCIO4 from 25° to 250°C

1968 ◽  
Vol 22 (5) ◽  
pp. 545-548 ◽  
Author(s):  
W. C. Waggener ◽  
A. J. Weinberger ◽  
R. W. Stoughton
Keyword(s):  
Cell Wall ◽  
Corrosion Products ◽  
Spectral Measurements ◽  
Wide Range ◽  
General Program ◽  
Cell Window ◽  
Temperature And Pressure

Dilute nitric, sulfuric, and perchloric acids are applicable as solvents for spectrophotometry up to 250°C over the following ranges: 0 to 1.0 f HNO3 from 0.6 to 1.2 μ; 0 to 0.2 f H2SO4 from 0.25 to 1.2 μ; and 0 to 1.0 f DClO4 from 0.25 to 1.8 μ. Each of these acids reacts measurably with the titanium cell wall and the sapphire windows at rates which increase with acidity and temperature. This corrosion affects the spectral measurements as a function of time and is associated with deterioration of cell window surfaces and the presence in the sample of dissolved and suspended corrosion products. These results are part of our more general program for the development of equipment and technique for routine spectrophotometry of pure liquids and solutions over a wide range of temperature and pressure.

scholarly journals Infection Prevention Time Required for Construction and Design at a Large Tertiary-Care Hospital, 2019

2020 ◽  
Vol 41 (S1) ◽  
pp. s69-s70
Author(s):  
Angie Dains ◽  
Michael Edmond ◽  
Daniel Diekema ◽  
Stephanie Holley ◽  
Oluchi Abosi ◽  
...  
Keyword(s):  
Infection Control ◽  
Patient Care ◽  
Construction Projects ◽  
Small Scale ◽  
Care Hospital ◽  
Class Iii ◽  
Construction Sites ◽  
Wide Range ◽  
Time Required ◽  
Class Iv

Background: Including infection preventionists (IPs) in hospital design, construction, and renovation projects is important. According to the Joint Commission, “Infection control oversights during building design or renovations commonly result in regulatory problems, millions lost and even patient deaths.” We evaluated the number of active major construction projects at our 800-bed hospital with 6.0 IP FTEs and the IP time required for oversight. Methods: We reviewed construction records from October 2018 through October 2019. We classified projects as active if any construction occurred during the study period. We describe the types of projects: inpatient, outpatient, non–patient care, and the potential impact to patient health through infection control risk assessments (ICRA). ICRAs were classified as class I (non–patient-care area and minimal construction activity), class II (patients are not likely to be in the area and work is small scale), class III (patient care area and work requires demolition that generates dust), and class IV (any area requiring environmental precautions). We calculated the time spent visiting construction sites and in design meetings. Results: During October 2018–October 2019, there were 51 active construction projects with an average of 15 active sites per week. These sites included a wide range of projects from a new bone marrow transplant unit, labor and delivery expansion and renovation, space conversion to an inpatient unit to a project for multiple air handler replacements. All 51 projects were classified as class III or class IV. We visited, on average, 4 construction sites each week for 30 minutes per site, leaving 11 sites unobserved due to time constraints. We spent an average of 120 minutes weekly, but 450 minutes would have been required to observe all 15 sites. Yearly, the required hours to observe these active construction sites once weekly would be 390 hours. In addition to the observational hours, 124 hours were spent in design meetings alone, not considering the preparation time and follow-up required for these meetings. Conclusions: In a large academic medical center, IPs had time available to visit only a quarter of active projects on an ongoing basis. Increasing dedicated IP time in construction projects is essential to mitigating infection control risks in large hospitals.Funding: NoneDisclosures: None

Spinal anesthesia in contemporary and complex lumbar spine surgery: experience with 343 cases

2021 ◽  
pp. 1-8
Author(s):  
Jeffrey M. Breton ◽  
Calvin G. Ludwig ◽  
Michael J. Yang ◽  
T. Jayde Nail ◽  
Ron I. Riesenburger ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Spinal Anesthesia ◽  
Spine Surgery ◽  
Outcome Data ◽  
Lumbar Spine Surgery ◽  
Class Iii ◽  
Instrumented Fusion ◽  
Fusion Procedure ◽  
Physical Status Classification ◽  
Wide Range

OBJECTIVE Spinal anesthesia (SA) is an alternative to general anesthesia (GA) for lumbar spine surgery, including complex instrumented fusion, although there are relatively few outcome data available. The authors discuss their experience using SA in a modern complex lumbar spine surgery practice to describe its utility and implementation. METHODS Data from patients receiving SA for lumbar spine surgery by one surgeon from March 2017 to December 2020 were collected via a retrospective chart review. Cases were divided into nonfusion and fusion procedure categories and analyzed for demographics and baseline medical status; pre-, intra-, and postoperative events; hospital course, including Acute Pain Service (APS) consults; and follow-up visit outcome data. RESULTS A total of 345 consecutive lumbar spine procedures were found, with 343 records complete for analysis, including 181 fusion and 162 nonfusion procedures and spinal levels from T11 through S1. The fusion group was significantly older (mean age 65.9 ± 12.4 vs 59.5 ± 15.4 years, p < 0.001) and had a significantly higher proportion of patients with American Society of Anesthesiologists (ASA) Physical Status Classification class III (p = 0.009) than the nonfusion group. There were no intraoperative conversions to GA, with infrequent need for a second dose of SA preoperatively (2.9%, 10/343) and rare preoperative conversion to GA (0.6%, 2/343) across fusion and nonfusion groups. Rates of complications during hospitalization were comparable to those seen in the literature. The APS was consulted for 2.9% (10/343) of procedures. An algorithm for the integration of SA into a lumbar spine surgery practice, from surgical and anesthetic perspectives, is also offered. CONCLUSIONS SA is a viable, safe, and effective option for lumbar spine surgery across a wide range of age and health statuses, particularly in older patients and those who want to avoid GA. The authors’ protocol, based in part on the largest set of data currently available describing complex instrumented fusion surgeries of the lumbar spine completed under SA, presents guidance and best practices to integrate SA into contemporary lumbar spine practices.

scholarly journals Insights into the Mode of Action of Chitosan as an Antibacterial Compound

2008 ◽  
Vol 74 (12) ◽  
pp. 3764-3773 ◽  
Author(s):  
Dina Raafat ◽  
Kristine von Bargen ◽  
Albert Haas ◽  
Hans-Georg Sahl
Keyword(s):  
Antimicrobial Activity ◽  
Cell Wall ◽  
Cell Membrane ◽  
Mode Of Action ◽  
Membrane Lipids ◽  
Expression Profiles ◽  
Transcriptional Response ◽  
Response Analysis ◽  
Sequence Of Events ◽  
Wide Range

ABSTRACT Chitosan is a polysaccharide biopolymer that combines a unique set of versatile physicochemical and biological characteristics which allow for a wide range of applications. Although its antimicrobial activity is well documented, its mode of action has hitherto remained only vaguely defined. In this work we investigated the antimicrobial mode of action of chitosan using a combination of approaches, including in vitro assays, killing kinetics, cellular leakage measurements, membrane potential estimations, and electron microscopy, in addition to transcriptional response analysis. Chitosan, whose antimicrobial activity was influenced by several factors, exhibited a dose-dependent growth-inhibitory effect. A simultaneous permeabilization of the cell membrane to small cellular components, coupled to a significant membrane depolarization, was detected. A concomitant interference with cell wall biosynthesis was not observed. Chitosan treatment of Staphylococcus simulans 22 cells did not give rise to cell wall lysis; the cell membrane also remained intact. Analysis of transcriptional response data revealed that chitosan treatment leads to multiple changes in the expression profiles of Staphylococcus aureus SG511 genes involved in the regulation of stress and autolysis, as well as genes associated with energy metabolism. Finally, a possible mechanism for chitosan's activity is postulated. Although we contend that there might not be a single classical target that would explain chitosan's antimicrobial action, we speculate that binding of chitosan to teichoic acids, coupled with a potential extraction of membrane lipids (predominantly lipoteichoic acid) results in a sequence of events, ultimately leading to bacterial death.

scholarly journals Nutritionally variant streptococci.

1991 ◽  
Vol 4 (2) ◽  
pp. 184-190 ◽  
Author(s):  
K L Ruoff
Keyword(s):  
Cell Wall ◽  
Oral Cavity ◽  
Successful Treatment ◽  
Distinct Species ◽  
Growth Conditions ◽  
Clinical Specimens ◽  
Wide Range ◽  
Streptococcal Species ◽  
A Cell

Streptococci requiring either pyridoxal or L-cysteine for growth were first observed 30 years ago as organisms forming satellite colonies adjacent to colonies of "helper" bacteria. Although they were previously considered nutritional mutants of viridans streptococcal species, the nutritionally variant streptococci (NVS) are currently thought to belong to distinct species of the genus Streptococcus. NVS strains may display pleomorphic cellular morphologies, depending on their growth conditions, and are distinguished from most other streptococci by enzymatic and serological characteristics and the presence of a cell wall chromophore. NVS are found as normal inhabitants of the oral cavity, and in addition to their participation in endocarditis, they have been isolated from a wide range of clinical specimens. Endocarditis caused by NVS is often difficult to eradicate; combinations of penicillin and an aminoglycoside are recommended for treatment. The unique physiological features of the NVS contribute to the difficulties encountered in their recovery from clinical specimens and may play a role in the problems associated with successful treatment of NVS endocarditis.

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