Mycoparasitic species of Trichoderma produce lectins

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.

Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 189
Author(s):  
Omar A. Hewedy ◽  
Khalid S. Abdel Lateif ◽  
Mahmoud F. Seleiman ◽  
Ashwag Shami ◽  
Fawziah M. Albarakaty ◽  
...  

Trichoderma species are known as excellent biocontrol agents against soil-borne pathogens that cause considerable crop losses. Eight strains of Trichoderma were isolated from five Egyptian regions. They identified based on translation elongation factor-1α (TEF1) sequencing as four different Trichoderma species: Trichoderma asperellum, Trichoderma harzianum, Trichoderma viride, and Trichoderma longibrachiatum. Optimal growth conditions (temperature and media), and the phosphate solubilization capability of Trichoderma strains were evaluated in vitro. Further, the ability of these strains to antagonize Fusarium solani, Macrophomina phaseolina, and Fusarium graminearum was also evaluated. The results revealed that Trichoderma harzianum (Th6) exhibited the highest antagonistic ability against F. solani, M. phaseolina and F. graminearum with inhibition rates of 71.42%, 72.97%, and 84.61%, respectively. Trichoderma viride (Tv8) exhibited the lowest antagonism against the same pathogens with inhibition rates of 50%, 64% and 69.23%, respectively. Simple-sequence repeats (SSRs) and random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic variability of the Trichoderma strains. The results revealed that of 45 RAPD amplified bands, 36 bands (80%) were polymorphic and of SSRs amplified 36 bands, 31 bands (86.11%) were polymorphic. The amplification of calmodulin and β-1,3-endoglucanase was noted at 500 bp and 230 bp, respectively. Data indicated that T. viride (Tv8) had the highest phosphate solubilization index (10.0 mm), while T. harzianum (Th6) had the lowest phosphate solubilization index (4.0 mm). In conclusion, T. harzianum (Th6) had the highest antagonistic activity in dual culture assay along with the growth rate; while T. viride (Tv8) had the highest phosphate solubilization activity. There are still gaps in obtaining new formulations, selecting potent Trichoderma strains to confirm disease control in planta. For improving Trichoderma recommendation in the organic agricultural system and sustaining the fertility of the soil, the field application of highly antagonistic biocontrol agents in different types of soil and plant species will be the first approach toward bio-pesticide treatments along with bio-fertilizer inoculation. Furthermore, secondary metabolites will be investigated for the most promising strains with the combination of different pathogens and application timing.


2011 ◽  
Vol 51 (3) ◽  
pp. 252-260 ◽  
Author(s):  
Gaber Elkot ◽  
Aly Derbalah

Use of Cultural Filtrates of Certain Microbial Isolates for Powdery Mildew Control in SquashPowdery mildew induces significant losses in yield and quality of squash. Therefore, culture filtrates of certain microbial isolates, (Epicoccum nigrum,Epicoccum minitans,Epicoccumsp.,Trichoderma harzianum,Trichoderma virideandBacillus pumilus) were used alone, and in combination with the fungicide penconazole to control powdery mildew in squash, under field conditions. Moreover, GC-MS analysis was carried out to identify the chemical components of the most effective culture filtrates against powdery mildew pathogen. The results showed that culture filtrates of different microbial isolates (except forTrichoderma harzianum) were more effective against powdery mildew in squash than the tested fungicide alone at the recommended levels, in both tested seasons. The results also showed that mixing different culture filtrates with penconazole improved efficiency against powdery mildew compared to using the fungicide alone, in both tested seasons. The efficacy of the culture filtrates of the tested microbial isolates against powdery mildew were due to the presence of a mixture of known antifungal compounds. The results suggest the possible use of the culture filtrates of the tested microbial isolates as alternative to fungicides, in powdery mildew control. Also, this study suggests the possible mixing of the culture filtrate of the tested biocontrol agents with fungicides to minimize the applied amount of fungicides.


2017 ◽  
Vol 9 (4) ◽  
pp. 2327-2331 ◽  
Author(s):  
Balkishan Chaudhary ◽  
Sanjeev Kumar ◽  
Shiva Kant Kushwaha

Three biocontrol agent viz., Trichoderma viride, Trichoderma virens and Trichoderma harzianum were evaluated to test the antagonism against Fusarium udum under in vitro conditions. All the three biocontrol agents have the potential of parasitizing the growth of Fusarium udum in vitro. The rate of parasitism was found fastest in T. viride (61.12% over growth in 96 hrs) than T. virens and T. harzianum. The volatile compounds from Trichoderma viride suppressed the mycelial growth of Fusarium udum by 43.13% and found effective when compared to Tricho-derma virens and Trichoderma harzianum. Non-volatile compounds or culture filtrate from Trichoderma virens at 15% concentration shows complete mycelial inhibition of the test fungi. The antagonist T. virens was chosen to be the most promising bio-control agent for F. udum.


2021 ◽  
Vol 50 (2) ◽  
pp. 423-425
Author(s):  
Ramesh Kumar ◽  
Sanjeev Kumar ◽  
Balkishan Chaudhary

Six biocontrol treatments viz., Trichoderma viride, Trichoderma virens, Trichoderma harzianum, T. harzianum + T. viride, T. harzianum + T. virens and T. viride + T. virens were evaluated to test the antagonism against Fusarium verticillioides under in vitro conditions. The maximum growth inhibition (90.6%) was recorded in consortium of T. harzianum + T. viride in dual culture technique . The volatile and non volatile compounds from the consortium of T. harzianum + T. viride also found best and suppressed the mycelial growth of F. verticillioides to the tune of 83.90 and 84.61 %, respectively. Bangladesh J. Bot. 50(2): 423-425, 2021 (June)


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.


2015 ◽  
Vol 39 (1) ◽  
pp. 167-176 ◽  
Author(s):  
Daniele Franco Martins Machado ◽  
Antonio Padilha Tavares ◽  
Sidinei José Lopes ◽  
Antonio Carlos Ferreira da Silva

Neste trabalho, o objetivo foi avaliar o efeito de isolados de Trichoderma spp. na emergência de plântulas e no crescimento de mudas de cambará (Gochnatia polymorpha). Utilizou-se, em casa de vegetação, substrato esterilizado e não esterilizado, sendo avaliados os efeitos de quatro isolados de trichoderma: TSM1 e TSM2 de Trichoderma viride, 2B2 e 2B22 de Trichoderma harzianum mais um mix preparado com a mistura desses quatro isolados, além de dois produtos comerciais à base de trichoderma. A análise dos dados permitiu concluir que os isolados de trichoderma testados não interferem na emergência das plântulas, mas os isolados 2B2 e 2B22 de T. harzianum apresentam potenciais como promotores de crescimento de mudas de cambará.


1980 ◽  
Vol 110 (7) ◽  
pp. 1473-1478 ◽  
Author(s):  
Asaf A. Qureshi ◽  
Warrén C. Burger ◽  
Neville Prentice ◽  
Charles E. Elson

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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