scholarly journals Endo-β-1,3-glucanase (GH16 Family) from Trichoderma harzianum Participates in Cell Wall Biogenesis but Is Not Essential for Antagonism Against Plant Pathogens

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 781 ◽  
Author(s):  
Marcela Suriani Ribeiro ◽  
Renato Graciano de Paula ◽  
Aline Raquel Voltan ◽  
Raphaela Georg de Castro ◽  
Cláudia Batista Carraro ◽  
...  

Trichoderma species are known for their ability to produce lytic enzymes, such as exoglucanases, endoglucanases, chitinases, and proteases, which play important roles in cell wall degradation of phytopathogens. β-glucanases play crucial roles in the morphogenetic-morphological process during the development and differentiation processes in Trichoderma species, which have β-glucans as the primary components of their cell walls. Despite the importance of glucanases in the mycoparasitism of Trichoderma spp., only a few functional analysis studies have been conducted on glucanases. In the present study, we used a functional genomics approach to investigate the functional role of the gluc31 gene, which encodes an endo-β-1,3-glucanase belonging to the GH16 family in Trichoderma harzianum ALL42. We demonstrated that the absence of the gluc31 gene did not affect the in vivo mycoparasitism ability of mutant T. harzianum ALL42; however, gluc31 evidently influenced cell wall organization. Polymer measurements and fluorescence microscopy analyses indicated that the lack of the gluc31 gene induced a compensatory response by increasing the production of chitin and glucan polymers on the cell walls of the mutant hyphae. The mutant strain became more resistant to the fungicide benomyl compared to the parental strain. Furthermore, qRT-PCR analysis showed that the absence of gluc31 in T. harzianum resulted in the differential expression of other glycosyl hydrolases belonging to the GH16 family, because of functional redundancy among the glucanases.

2019 ◽  
Vol 7 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Nabin Pandey ◽  
Madhusudhan Adhikhari ◽  
Binod Bhantana

In the world, the traditional agricultural practices are getting affected by various problems such as disease, pest, drought, decreased soil fertility due to use of hazardous chemical pesticides, pollution and global warming. As a result, there is a need for some eco-friendly bio-control agents that help in resolving the previous mentioned problems. The various types of biological control agents such as bacteria and fungi are involved in bio-control activity. Among them, fungal genus Trichoderma plays a major role in controlling the plant diseases. Species of Trichoderma are diverse fungal microbial community known and explored worldwide for their versatilities as biocontrol and growth promoting agents. These fungi reproduce asexually by production of conidia and chlamydospores and in wild habitats by ascospores. Trichoderma species are efficient mycoparasites and prolific producers of secondary metabolites, some of which have clinical importance. However, the ecological or biological significance of this metabolite diversity is sorely lagging behind the chemical significance. Several Trichoderma spp. positively affect plants by stimulating plant growth, and protecting plants from fungal and bacterial pathogens. They are used in biological plant protection as bio-fungicides as well as in bioremediation. A large number of research groups are working on various aspects of Trichoderma viz., diversity, ecology and their applications. The capacity of Trichoderma fungi to produce lytic enzymes is used in animal feed, and wine making and brewery industries. Trichoderma spp. are the most successful bio-control agents as more than 60% of the registered bio-fungicides used in today’s agriculture belongs to Trichoderma -based formulation. The increase in incidence and severity of diseases and emergence of new diseases causes the significant yield losses of different crops in Nepal. But the research and studies on plant diseases are limited. Int. J. Appl. Sci. Biotechnol. Vol 7(3): 309-316  


1971 ◽  
Vol 125 (2) ◽  
pp. 461-471 ◽  
Author(s):  
K. W. Buck ◽  
M. A. Obaidah

1. The cell wall of Fusicoccum amygdali consisted of polysaccharides (85%), protein (4–6%), lipid (5%) and phosphorus (0.1%). 2. The main carbohydrate constituent was d-glucose; smaller amounts of d-glucosamine, d-galactose, d-mannose, l-rhamnose, xylose and arabinose were also identified, and 16 common amino acids were detected. 3. Chitin, which accounted for most of the cell-wall glucosamine, was isolated in an undegraded form by an enzymic method. Chitosan was not detected, but traces of glucosamine were found in alkali-soluble and water-soluble fractions. 4. Cell walls were stained dark blue by iodine and were attacked by α-amylase, with liberation of glucose, maltose and maltotriose, indicating the existence of chains of α-(1→4)-linked glucopyranose residues. 5. Glucose and gentiobiose were liberated from cell walls by the action of an exo-β-(1→3)-glucanase, giving evidence for both β-(1→3)- and β-(1→6)-glucopyranose linkages. 6. Incubation of cell walls with Helix pomatia digestive enzymes released glucose, N-acetyl-d-glucosamine and a non-diffusible fraction, containing most of the cell-wall galactose, mannose and rhamnose. Part of this fraction was released by incubating cell walls with Pronase; acid hydrolysis yielded galactose 6-phosphate and small amounts of mannose 6-phosphate and glucose 6-phosphate as well as other materials. Extracellular polysaccharides of a similar nature were isolated and may be formed by the action of lytic enzymes on the cell wall. 7. About 30% of the cell wall was resistant to the action of the H. pomatia digestive enzymes; the resistant fraction was shown to be a predominantly α-(1→3)-glucan. 8. Fractionation of the cell-wall complex with 1m-sodium hydroxide gave three principal glucan fractions: fraction BB had [α]D +236° (in 1m-sodium hydroxide) and showed two components on sedimentation analysis; fraction AA2 had [α]D −71° (in 1m-sodium hydroxide) and contained predominantly β-linkages; fraction AA1 had [α]D +40° (in 1m-sodium hydroxide) and may contain both α- and β-linkages.


2006 ◽  
Vol 19 (12) ◽  
pp. 1348-1358 ◽  
Author(s):  
Harold J. G. Meijer ◽  
Peter J. I. van de Vondervoort ◽  
Qing Yuan Yin ◽  
Chris G. de Koster ◽  
Frans M. Klis ◽  
...  

The oomycete genus Phytophthora comprises a large group of fungal-like plant pathogens. Two Phytophthora genomes recently have been sequenced; one of them is the genome of Phytophthora ramorum, the causal agent of sudden oak death. During plant infection, extracellular proteins, either soluble secreted proteins or proteins associated with the cell wall, play important roles in the interaction with host plants. Cell walls of P. ramorum contain 1 to 1.5% proteins, the remainder almost exclusively being accounted for by glucan polymers. Here, we present an inventory of cell-wall-associated proteins based on mass spectrometric sequence analysis of tryptic peptides obtained by proteolytic digestion of sodium dodecyl sulfate-treated mycelial cell walls. In total, 17 proteins were identified, all of which are authentic secretory proteins. Functional classification based on homology searches revealed six putative mucins or mucin-like proteins, five putative glycoside hydrolases, two transglutaminases, one annexin-like protein, the elicitin protein RAM5, one protein of unknown function, and one Kazal-type protease inhibitor. We propose that the cell wall proteins thus identified are important for pathogenicity.


2006 ◽  
Vol 5 (3) ◽  
pp. 507-517 ◽  
Author(s):  
F. Castrejon ◽  
A. Gomez ◽  
M. Sanz ◽  
A. Duran ◽  
C. Roncero

ABSTRACT The Saccharomyces cerevisiae ynl294cΔ (rim21Δ) mutant was identified in our lab owing to its moderate resistance to calcofluor, although it also displayed all of the phenotypic traits associated with its function as the putative sensor (Rim21p) of the RIM101 pathway. rim21Δ also showed moderate hypersensitivity to sodium dodecyl sulfate, caffeine, and zymolyase, and the cell wall compensatory response in this mutant was very poor, as indicated by the almost complete absence of Slt2 phosphorylation and the modest increase in chitin synthesis after calcofluor treatment. However, the cell integrity pathway appeared functional after caffeine treatment or thermal stress. rim21Δ and rim101Δ mutant strains shared all of the cell-wall-associated phenotypes, which were reverted by the expression of Rim101-531p, the constitutively active form of this transcription factor. Therefore, the absence of a functional RIM101 pathway leads to cell wall defects. rim21Δ, as well as rim101Δ, was synthetic lethal with slt2Δ, a synthetic defect alleviated by osmotic stabilization of the media. The double mutants grown in osmotically stabilized media were extremely hypersensitive to zymolyase and showed thicker cell walls, with poorly defined mannoprotein layers. In contrast, rim21Δ rlm1Δ and rim101Δ rlm1Δ double mutants were fully viable. Taken together, these results show that the RIM101 pathway participates directly in cell wall assembly and that it acts in parallel with the protein kinase C pathway (PKC) in this process independently of the transcriptional effect of the compensatory response mediated by this route. In addition, these results provide new experimental evidence of the direct involvement of the PKC signal transduction pathway through the Sltp2 kinase in the construction of yeast cell walls.


Author(s):  
Jaygendra Kumar ◽  
Mukesh Kumar ◽  
Akash Tomar ◽  
. Vaishali ◽  
Pushpendra Kumar ◽  
...  

Trichoderma species are well known for their biocontrol activity which colonize many soil and tuber-borne and foliage plant pathogens. In this study, 12 native isolates of Trichiderma spp were collected from various crop rhizosphere soil samples and characterized them phenotypically based on morphological and cultural features and genotypically based on sequence analysis of internal transcribed spacer (ITS) region-PCR amplification. The results obtained from phenotypic and genotypic observation revealed that isolates were belonged to five different species namely T. asperellum, T. harzianum, T. longibrachiatum, T. koningii and T. koningiopsis. All Trichoderma isolates produced ~600 bp amplicon and phylogenetic analysis revealed that all isolates were grouped with respective species. Further, the antagonistic potential of all the isolates was evaluated against Fusarium spp. following in vitro dual culture method. The results showed that isolates of T. harzianum exhibited maximum growth inhibition activity. The highest rate of inhibition was recorded with T. harzianum isolate TBT6 (87.1%) followed by TBT7 (82.2%), while the least inhibition was observed in T. longibrachiatum isolate TBT10 (59.7%) after 7 days of incubation. The antagonistic T. harzianum isolate TBT6 can be used for development of Trichoderma based bio-formulation and served as bio-control agent against Fusaium spp. under field conditions.


2020 ◽  
Vol 13 (1) ◽  
pp. 222-226
Author(s):  
Henny V.G. Makal ◽  
Max M. Ratulangi ◽  
Denny S. Sualang

The objectives of this study are: (1) to inventory Trichoderma spp. in North Minahasa District, South Minahasa District, and Tomohon City-Minahasa District, (2) inventory of Trichoderma spp. in the rhizosphere of cultivated and fallow gardens, and (3) calculate the population density of Trichoderma spp. all soil samples. The scope of this study is the biological control of plant pathogens, induce plant resistance, and biological fertilizer production. Trichoderma isolation spp. has been carried out by dilution method and cultured on PDA + antibiotics. Population density of Trichoderma spp. calculated using the plate calculation method. Identification of this species function based on the color and patterns of sporulation in the colony; hyphae and clamydospores; conidiophores; and phialides and phialospores. Trichoderma species found in North Minahasa District were T. harzianum, T. koningii, and T. viride; in South Minahasa District, T. koningii and T. viride; and in Tomohon City-Minahasa District, T. koningii and T. viride. In fallow gardens were T. harzianum, T. koningii, and T. viride, and in cultivated gardens were T. koningii and T. viride. Population densities of Trichoderma sp. in South Minahasa District, North Minahasa District, and Tomohon City-Minahasa District, respectively 1,363.64, 466.67, and 26.67 CFU / g soil.


2021 ◽  
Vol 22 (18) ◽  
pp. 9888
Author(s):  
Lakshmipriya Perincherry ◽  
Monika Urbaniak ◽  
Izabela Pawłowicz ◽  
Karolina Kotowska ◽  
Agnieszka Waśkiewicz ◽  
...  

Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, β-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation.


1975 ◽  
Vol 21 (4) ◽  
pp. 442-452 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths

Hyaline hyphae of Phomopsis become pigmented when exposed to short periods of light. Pigment was deposited in the form of melanin granules both within the cell wall and within mucilaginous excrescences that were developed irregularly over the hyphal surface. Analysis of the pigment showed it to have properties similar to that of "Dopa" melanin and to pigments previously isolated from fungal cell walls. Lysis of both hyaline and pigmented hyphal walls by means of lytic enzymes was minimal. It is suggested that the major role of melanin in this fungus is the protection of cellular organelles from harmful ionizing radiations.


2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Maria Lucia Garcia Simoes ◽  
Samia Maria Tauk-Tornisielo ◽  
Givaldo Rocha Niella ◽  
Daniel Mario Tapia Tapia

Trichoderma species , isolated from different producer regions of cocoa (Bahia, Brazil), were evaluated as for their capacity of usage in the biocontrol of the basidiomycete Moniliophthora perniciosa subgroup 1441, which causes the witches’ broom in cocoa. The isolates of Trichoderma were evaluated through individual indices so called %AP (Antagonistic Potential to Moniliophthora perniciosa subgroup 1441), %PG (Potential Growth in vitro) and %PSPr (Potential of Spore Production on rice) These indices were evaluated together, also they were used for the determination of Biological Control Potential (%BCP) of each antagonistic specie to the evaluated pathogen. Afterwards, the ability of the antagonistic to colonize and to produce spores on sterilized dry brooms was also evaluated. Some of the isolates Trichoderma spp showed a high %AP to the pathogen and high %PG, but did not present a significant %PSPr, turning impossible the spore production for biocontrol at commercial level. Significant differences were found within the individual indices among the species and isolates of the same species of Trichoderma spp, pointing out a great genetic variability among them. Trichoderma harzianum 911 showed to have the best biocontrol potential to the pathogen when compared to the other isolates, presenting a %BCP de 91.86% (mainly by the high %AP of 97,76%) a %PSPr of 99.53%, also producing 22.67 spores x 109. mL-1 by dry broom segment. Trichoderma harzianum 911 showed to be as promising isolate for future researches on biocontrol of cocoa witches’ broom.


Sign in / Sign up

Export Citation Format

Share Document