Peroxidase in healthy and diseased elm trees investigated by the benzidine histochemical technique

1968 ◽  
Vol 46 (12) ◽  
pp. 1491-1494 ◽  
Author(s):  
Camilien Gagnon

Peroxidase activity was localized in the xylem of healthy and diseased American elm trees by the benzidine test. The activity in the cell walls resulted in a violet-brown color, while the activity in the protoplasm produced a blue reaction. The localization of the enzyme in healthy trees was much improved by impregnation of tissues with celloidin before sectioning; this procedure reduced the diffusion of peroxidase from the tissues into the incubation solution. The cambium region of both healthy and diseased trees showed a very strong peroxidase activity; such activity was also detected in ray and axial parenchyma cells. Only in infected trees was the activity found in fibers and vessels. The role of peroxidase in the pathological alteration of xylem tissues is discussed.

1984 ◽  
Vol 62 (12) ◽  
pp. 2644-2649 ◽  
Author(s):  
M. Harche

Using diaminobenzidine as substrate, peroxidase activity was localized in the walls of parenchyma cells and differentiating fibres. In mature fibres and parenchyma a slight activity could be recognized in primary walls only. In parenchyma cells, peroxidase activity was fairly inhibited with heat, potassium cyanide, and aminotriazole, which could indicate the presence of catalase within the cell walls. However, in plasmodesmatal regions peroxidases were- resistant to the above inhibitors. Syringaldazine oxidase activity was present only in the primary wall and the outer part of the secondary wall of differentiating fibres. The parallelism between lignification and peroxidase activity in the secondary walls supports the hypothesis of the involvement of these enzymes in the lignification process.


2010 ◽  
Vol 59 (4) ◽  
pp. 249-255
Author(s):  
LUCYNA PAWŁOWSKA-ĆWIĘK

Earlier research demonstrated the secretion of benzoate, which must be oxygenated to its 4-hydroxy derivative in order to be included in further sulfate uptake processes. The present study on Desulfotomaculum acetoxidans DSM 771 was designed to determine the activity and catalytic specificity of the enzyme (most probably peroxidase) catalyzing the hydroxylation of secreted benzoate. Peroxidase activity measured with ABTS (2,2'-azino-bis (3-ethylbenzathiazoline-6-sulfonic acid) during cultivation indicated the greatest activity on the third and thirteen days (3.4 and 2.3 nkat per ml sample respectively). The highest (0.7979) correlation coefficient was calculated between peroxidase activity and hydrogen peroxide levels. The cell walls from 3- and 13-day cultures were subjected to an isolation procedure, PIPES (piperazine-N,N'-bis (2-ethane-sulfonic acid) extract followed by preparative electrophoresis. The extracts of a approximately 30 kDa band on the gel were analyzed by Western blotting and the membrane was stained with TMB (3,3',5,5'-tetramethylbenzidine-specific for the presence of peroxidase). This same protein was incubated for 6 h with benzoate, H2O2, Na2SO4. The product formed a complex with Fe3+, whose maximum absorption spectra (501.7 nm) corresponded with a ferric complex of synthetic 4-hydroxy-3-sulfo-benzoate. The H2S level during the cultivation was higher in culture grown with 15.5 mM 4-hydroxy-3-sulfo-benzoate than in culture with lactate supplemented with 15.5 mM sulfate. The role of peroxidase in oxygen utilization and sulfate uptake is discussed.


IAWA Journal ◽  
1998 ◽  
Vol 19 (2) ◽  
pp. 191-206 ◽  
Author(s):  
Sherwin Carlquist

Wood and bark anatomy are described for four species of three genera of Caricaceae; both root and stem material were available for Jacaratia hassleriana. Wood of all species lacks libriform fibers in secondary xylem, and has axial parenchyma instead. Cylicomorpha parviflora has paratracheal parenchyma cells with thin lignified walls; otherwise, all cell walls of secondary xylem in Caricaceae except those of vessels have only primary walls. Vessels have alternate laterally elongate (pseudoscalariform) pits on vessel-vessel interfaces, but wide, minimally bordered scalariform pits on vessel-parenchyma contacts. Laticifers occur commonly in tangential plates in fascicular secondary xylem, and rarely in xylem rays. Proliferation of axial parenchyma by zones of tangential divisions is newly reported for the family. Bark is diverse in the species, although some features (e.g., druses) are common to all. Wood of Caricaceae is compared to that of two species of Moringaceae, recently designated the sister family of Caricaceae. Although the wood and bark of Moringa oleifera, a treelike species, differ from those of Caricaceae, wood and bark of the stem succulent M. hildebrandtii, the habit of which resembles those in Caricaceae, simulate wood and bark of Caricaceae closely. Counterparts to laticifers in Moringaceae are uncertain, however. Phloem fibers of Caricaceae form an expansible peripheral cylinder of mechanical tissue that correlates with the stem succulence of most species of Caricaceae.


1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.


2014 ◽  
Vol 15 (5) ◽  
pp. 1727-1736 ◽  
Author(s):  
Sarah N. Kiemle ◽  
Xiao Zhang ◽  
Alan R. Esker ◽  
Guillermo Toriz ◽  
Paul Gatenholm ◽  
...  
Keyword(s):  

1981 ◽  
Vol 59 (2) ◽  
pp. 251-263 ◽  
Author(s):  
X. Mourichon ◽  
G. Sallé

An electron microscopic study was performed on haustoria of Phytophthora cactorum (L. et C.) Schroeter developed in tissues of two cultivars of apple fruits: a susceptible variety ('Golden delicious') and a resistant one ('Belle de Boskoop'). Ultrastructure of intercellular hyphae and some aspects of their penetration between contiguous host cells were described. A light dissolution of the host cell walls was observed. Ontogenic investigations indicated that in the susceptible host, the wall of the fungal haustoria was covered with a dense-stained extrahaustorial matrix. Its origin and its polysaccharide nature were demonstrated. On the other hand, the resistant host developed, immediately after the inoculation, a papilla which gave rise, later on, to a sheath enclosing adult haustoria. The role of these callosic structures in the phenomenon of resistance was discussed.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3747
Author(s):  
Weisheng Zhu ◽  
Luyao Wang ◽  
Qisi Li ◽  
Lizhi Jiao ◽  
Xiaokan Yu ◽  
...  

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H2O2), in which the nanozyme will promote the generation of ROS to kill bacteria based on the decomposition of H2O2. According to this criterion, a cerium oxide nanoparticle (Nanoceria, CeO2, a classical nanozyme with high peroxidase activity)-based nanozyme-H2O2 system would be very efficient for bacterial disinfection. However, CeO2 is a nanozyme with multiple enzyme-like activities. In addition to high peroxidase activity, CeO2 nanozymes also possess high superoxide dismutase activity and antioxidant activity, which can act as a ROS scavenger. Considering the fact that CeO2 nanozymes have both the activity to promote ROS production and the opposite activity for ROS scavenging, it is worth exploring which activity will play the dominating role in the CeO2-H2O2 system, as well as whether it will protect bacteria or produce an antibacterial effect. In this work, we focused on this discussion to unveil the role of CeO2 in the CeO2-H2O2 system, so that it can provide valuable knowledge for the design of a nanozyme-H2O2-based antibacterial system.


1998 ◽  
Vol 63 (3) ◽  
pp. 359-363 ◽  
Author(s):  
D. J. Schrier ◽  
R. C. Schimmer ◽  
C. M. Flory ◽  
D. K.-L. Tung ◽  
P. A. Ward
Keyword(s):  

1980 ◽  
Vol 58 (21) ◽  
pp. 2269-2273 ◽  
Author(s):  
H. B. Hanten ◽  
G. E. Ahlgren ◽  
J. B. Carlson

The anatomical development of the abscission zone in grains of Zizania aquatica L. was correlated with development of the embryo. The abscission zone is well developed when the embryo sac is mature. Soon after pollination, the first anatomical evidence of abscission appears as plasmolysis of the separation layer parenchyma cells. This is followed by separation of the layers by dissolution of the middle lamella and fragmentation of cell walls. Persistence of intact vascular tissue and presence of a surrounding cone-shaped mass of lignified cells may be involved in abscission of wild rice grains.


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