Release of peroxidase from soybean hypocotyl cell walls by Sclerotium rolfsii culture filtrates

1974 ◽  
Vol 52 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Neal M. Barnett

Up to 24% of the peroxidase of purified cell walls of soybean hypocotyls was released by incubation of cell walls with hydrolytic enzymes secreted by the fungus Sclerotium rolfsii. This estimate is based on comparison of peroxidase activity recovered in the medium with peroxidase activity in unincubated cell walls, estimated by a new assay. The peroxidase-release reaction occurs at 0 °C at half the rate at 30 °C. The peroxidase-release reaction occurs almost equally fast in the pH range of 3.5 to 8.0. The release of peroxidase from cell walls cannot be attributed solely to arabanase, polygalacturonase, or cellulase in the culture filtrate, although on Sephadex G-75 chromatography these activities overlap the peroxidase-releasing activity. Culture filtrate released less than 5% of the hydroxyproline protein of the cell walls.

1982 ◽  
Vol 28 (7) ◽  
pp. 719-725 ◽  
Author(s):  
Y. Elad ◽  
I. Chet ◽  
Y. Henis

Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii, as sole carbon source. Trichoderma harzianum also showed high activity of both enzymes when grown on homogenized S. rolfsii sclerotia. Glucanase activity increased by 67% when the fungus was grown on a mixture of laminarin and glucose (3:1, v/v). Similarly, high lytic activity was detected in wheat bran culture of the fungus and in soil inoculated with this culture. Protease and lipase activity were detected in the medium when the antagonist attacked mycelium of S. rolfsii.Isolates of T. harzianum were found to differ in the levels of hydrolytic enzymes produced when mycelium of S. rolfsii, Rhizoctonia solani, and Pythium aphanidermatum in soil was attacked. This phenomenon was correlated with the ability of each of the Trichoderma isolates to control the respective soilborne pathogens.


1974 ◽  
Vol 52 (9) ◽  
pp. 2037-2040 ◽  
Author(s):  
C. R. Curtis ◽  
Neal M. Barnett

Bound soybean hypocotyl cell wall proteins can be released from the cell wall by incubation with a culture filtrate of the fungal pathogen Sclerotium rolfsii. The released cell wall proteins were then separated by disc electrophoresis or isoelectric-focusing techniques in polyacrylamide gel columns and tested for peroxidase and esterase activity. Released cell wall proteins showed considerable peroxidase multiplicity, which was totally absent in the separation of fungal culture filtrate. Peroxidase patterns of some released cell wall peroxidases were similar to soybean cytoplasmic peroxidase patterns. In separate experiments, esterase bands were detected in the released cell wall proteins, but this was probably due to esterase activity of the fungal culture filtrate. Cytoplasmic esterases exhibited much higher isoelectric points than cell wall and culture filtrate esterases, which were concentrated between pH 3 and 6.


2020 ◽  
Vol 21 (5) ◽  
pp. 497-506
Author(s):  
Mayck Silva Barbosa ◽  
Bruna da Silva Souza ◽  
Ana Clara Silva Sales ◽  
Jhoana D’arc Lopes de Sousa ◽  
Francisca Dayane Soares da Silva ◽  
...  

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.


1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon

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.


1997 ◽  
Vol 43 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Luzia H. C. Lima ◽  
Cirano J. Ulhoa ◽  
Adrienne P. Fernandes ◽  
Carlos R. Felix

2018 ◽  
Vol 7 (3) ◽  
pp. 123-129 ◽  
Author(s):  
Fakher Ayed ◽  
Hayfa Jabnoun-Khiareddine ◽  
Rania Aydi-Ben-Abdallah ◽  
Mejda Daami-Remadi

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.


1996 ◽  
Vol 42 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Diane Neethling ◽  
Helena Nevalainen

Culture filtrates and mycelial extracts of two mycoparasitic Trichoderma species were tested for the presence of lectins, by haemagglutination with human and marsupial erythrocytes. In Trichoderma viride, haemagglutinating activity was present in both mycelial extracts and culture filtrate. While secreted lectins were only detected after 6 days of growth, the presence of mycelium-associated lectins was first noted in 3-day-old cultures. Agglutinating activity was also demonstrated in the mycelium of 6-, 9- and 13-day-old cultures of Trichoderma harzianum. In this species, however, lectins were not secreted. In all instances, haemagglutination was inhibited by N-acetylgalactosamine and related sugars. This is the first report on the occurrence of lectins in Trichoderma spp.Key words: Trichoderma, lectins, mycoparasitism.


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.


Biologia ◽  
2011 ◽  
Vol 66 (1) ◽  
Author(s):  
Yasushi Sato ◽  
Youko Yajima ◽  
Naohito Tokunaga ◽  
Ross Whetten

AbstractLignin is synthesized not only during morphogenesis of vascular plants but also in response to various stresses. Isolated Zinnia elegans mesophyll cells can differentiate into tracheary elements (TEs), and deposit lignin into cell walls in TE-inductive medium (D medium). Meanwhile isolated mesophyll cells cultured in hormone-free medium (Co medium) accumulate stress lignin-like substance during culture. Therefore this culture system is suitable for study of lignin and lignin-like substance formation.In D medium lignin was deposited in TEs, but in Co medium, extracellular lignin-like substance accumulated. Analysis of the culture media indicated the presence of dilignols in D culture, but not in Co culture. To investigate the fate of lignin precursors, we added coniferyl alcohol (CA) in each culture. In Co medium, CA was polymerized into dilignols rapidly but they were present only temporarily, and in D medium CA was polymerized into dilignols relatively slowly but their content increased continually.Meanwhile, in Co culture, peroxidase activity in the medium was much higher than the peroxidase activity bound ionically to the cell walls. In D culture, ionically bound peroxidase activity was higher than that in the medium. These results may suggest that lignin deposition in TEs is related to ionically bound peroxidases in D culture, and lignin-like substance deposition in the medium is related to peroxidases in the medium in Co culture.


1969 ◽  
Vol 15 (7) ◽  
pp. 681-688
Author(s):  
R. Turcotte

The erythrocyte-sensitizing ability (ESA), as measured by the bis-diazotized-benzidine hemagglutination test, was determined for the extractable and culture filtrate antigens of three strains of mycobacteria (H37Rv, H37Ra, and BCG). The ESA of the precipitated and supernatant fractions obtained from these preparations by precipitation with ammonium sulfate, was found to vary according to the age of the cultures: the concentration of antigens decreased in the bacillary extracts and increased in the corresponding culture filtrates with the aging of the mycobacterial cultures.The variation in the antigenic composition of bacterial extracts and of culture filtrates during the growth cycle was also demonstrated by immunodiffusion techniques in agar gel. However, all extractable antigens of a given Mycobacterium did not appear in the culture filtrates.


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