scholarly journals Trichoderma: a beneficial antifungal agent and insights into its mechanism of biocontrol potential

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Ria Mukhopadhyay ◽  
Deepak Kumar
Keyword(s):  
Biological Control ◽  
G Protein ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Main Body ◽  
Antifungal Metabolites ◽  
Camp Pathway ◽  
Wide Range ◽  
Biocontrol Potential ◽  
Chemical Pesticides

Abstract Background Agriculture is an indispensable part of any country to feed the millions of people but it is under constant threat of pests. To protect the crops from this huge yield loss recently, chemical pesticides are used. Though chemical pesticides have shown effective results in killing the crop pests, it causes negative impact on the environment as well as humans. So to find an eco-friendly alternative, biological control methods are being used. Main body Biological control is a great renaissance of interest and research in microbiological balance to control soil-borne plant pathogens and leads to the development of a better farming system. In biological control, genus Trichoderma serves as one of the best bioagents, which is found to be effective against a wide range of soil and foliar pathogens. Genus Trichoderma is a soil inhabiting green filamentous fungus, which belongs to the division Ascomycota. The efficacy of Trichoderma depends on many abiotic parameters such as soil pH, water retention, temperature and presence of heavy metals. The biocontrol potential of Trichoderma spp. is due to their complex interaction with plant pathogens either by parasitizing them, secreting antibiotics or by competing for space and nutrients. During mycoparasitic interactions, production of hydrolytic enzymes such as glucanase, chitinase and protease and also signalling pathways are initiated by Trichoderma spp. and the important ones are Heterotrimeric G protein, MAP kinase and cAMP pathway. G protein and MAPK are mainly involved in secretion of antifungal metabolites and the formation of infection structures. cAMP pathway helps in the condition and coiling of Trichoderma mycelium on pathogenic fungi and inhibits their proliferation. Short conclusion Trichoderma being an efficient biocontrol agent, their characteristics and mechanisms should be well understood to apply them in field conditions to restrict the proliferation of phytopathogens.

scholarly journals Microbial antagonists against plant pathogens in Iran: A review

2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Agricultural Products ◽  
Control Measures ◽  
Wide Range ◽  
Plant Disease Management ◽  
Published Research

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.

The Biocontrol Mechanism of Trichoderma asperellum Resistance Plant Pathogenic Fungi

2013 ◽  
Vol 726-731 ◽  
pp. 4525-4528
Author(s):  
Ping Yang ◽  
Qian Xu
Keyword(s):  
Cell Wall ◽  
Plant Pathogens ◽  
Control Plant ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Dry Weight ◽  
Plant Pathogenic Fungi ◽  
Cell Wall Degrading Enzymes ◽  
Antifungal Metabolites ◽  
Degrading Enzymes

T. asperellum is an important biocontrol fungus owing to their ability to antagonize plant pathogenic fungi. The biocontrol effects of T. asperellum were played by secreting many kinds of hydrolytic enzymes and antibiotics. T. asperellum producing more cell wall degrading enzymes when meeting plant pathogens. Moreover, the growth of the plant pathogens was inhibited by T. asperellum secondary metabolites. The yield of antibiotic 6-PP was 1.32 mg 6-PP/g mycelial dry weight. T. asperellum control plant pathogens through secreting cell wall degrading enzymes and producing antifungal metabolites.

scholarly journals A Review on the Biological Resistance of Terricolous Microorganisms

2018 ◽  
Vol 15 (2) ◽  
pp. 439-446
Author(s):  
Mitra Abootorabi
Keyword(s):  
Biological Control ◽  
Environmental Pollution ◽  
Plant Pathogens ◽  
Chemical Compounds ◽  
Systemic Resistance ◽  
Bacillus Species ◽  
Control Mechanisms ◽  
Resistant Species ◽  
Chemical Pesticides ◽  
Harmful Effects

The excessive use of chemical pesticides to confront pests causes environmental pollution. Furthermore, plant pathogens resist chemical pesticides. When such pathogens accumulate in plants or soil, they will cause harmful effects on humans. Biological control is an alternative method that reduces or terminates the use of chemical compounds in agriculture. Biological control is also carried out by microorganisms. Bacteria are the main group of these microorganisms. Due to the extensive presence in the soil, tolerating changes of temperature, pH, and salinity as well as producing endospore resistant species, Bacillus bacteria are used in biological control of soil. Bacillus species are often found in soil and rhizosphere. These bacteria help with the control of plant pathogens by producing siderophore, secretion of enzymes, production of antibiotics and inducing systemic resistance. In this study, various biological control mechanisms which are carried out by microorganisms have been reviewed.

scholarly journals Potential of some endophytic bacteria in biological control of root-knot nematode Meloidogyne incognita

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Shalaleh Moslehi ◽  
Salar Pourmehr ◽  
Akbar Shirzad ◽  
Reza Khakvar
Keyword(s):  
Biological Control ◽  
Meloidogyne Incognita ◽  
Endophytic Bacteria ◽  
Plant Pathogens ◽  
Bacterial Isolates ◽  
Inhibitory Effects ◽  
Root Knot Nematode ◽  
Isolation And Identification ◽  
Root Knot Nematodes ◽  
Biocontrol Potential

Abstract Background Root-knot nematodes (Meloidogyne spp.) are among the most important plant pathogens. Biological control is one of the safety and effective methods for control of these nematodes. The aim of the present study was the isolation and identification of endophytic bacteria from tomato fields in some areas of Iran in order to evaluate their biocontrol potential against root-knot nematode. In the present study, the population of Meloidogyne was collected from infected cucumber roots of a greenhouse, and the bacteria were isolated from tomato samples collected from the fields in West-Azarbaijan province of Iran. The effects of the bacterial isolates on hatching and mortality of nematode second-stage juveniles were evaluated, and the effects of six selected isolates on infection of a susceptible cultivar of tomato with nematode were evaluated under greenhouse conditions. Results The root-knot nematode was identified as Meloidogyne incognita. Results showed that the all isolates exhibited considerable inhibitory effects on nematode hatching. The bacterial isolates also caused the mortality of juveniles. Six bacterial isolates with notable biocontrol potential were selected, and supplementary experiments and molecular identification of selected bacterial isolates were performed. Isolates 1, 2, 5, 7, 10, and 11 were identified as follows: Bacillus wiedmannii (MW405861), Pseudoxantomonas mexicana (MW405860), Pseudomonas thivervalensis (MW405862), Serratia liquefaciens (MW405864), Pseudomonas chlororaphis (MW405863), and P. fluorescens (MW405825), respectively. Based on the results of the greenhouse experiment, the selected isolates exhibited good results in terms of reduction of galls and egg masses of nematode. However, B. wiedmannii and S. liquefaciens had the best results in reduction of all investigated factors compared to other isolates. P. mexicana, P. chlororaphis, and P. fluorescens resulted moderate effects. P. thivervalensis was less effective than the others and in some cases had no effect on nematode reduction. Conclusions The results showed that endophytic bacteria are good candidates for management of root-knot nematodes. The use of such agents instead of chemicals will be very valuable to the control of nematodes.

Biopesticides: Use of Rhizosphere Bacteria for Biological Control of Plant Pathogens

2016 ◽  
Vol 1 (2) ◽  
pp. 135 ◽  
Author(s):  
Satyavir S Sindhu ◽  
Anju Sehrawat ◽  
Ruchi Sharma ◽  
Anupma Dahiya
Keyword(s):  
Biological Control ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Crop Plants ◽  
Plant Diseases ◽  
Alternative Methods ◽  
Genetic Enhancement ◽  
Pests And Diseases ◽  
Antagonistic Microorganisms

The pesticides used to control pests and diseases are also implicated in ecological, environmental and human health hazards. To reduce the deleterious effects of these agrochemicals, certain antagonistic microorganisms have been characterised from rhizosphere of different crop plants that suppress various plant diseases and thus, minimize the use of pesticides. The application of these specific antagonistic microorganisms in biological control of soilborne pathogens has been studied intensively in the last two decades. These beneficial rhizosphere microorganisms inhibit the pathogenic bacteria and fungi by producing antibiotics, bacteriocins, siderophores, hydrolytic enzymes and other secondary metabolites. The efficiency of these biocontrol products can be improved by manipulation of the environment, using mixtures of beneficial organisms, physiological and genetic enhancement of the biocontrol mechanisms, manipulation of formulations and integration of biocontrol with other alternative methods that provide additive effects. These biocontrol agents could be effectively utilised in sustainable agriculture for improving growth of crop plants.

Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases

1993 ◽  
Vol 71 (3) ◽  
pp. 426-433 ◽  
Author(s):  
D. Yang ◽  
F. Plante ◽  
L. Bernier ◽  
Y. Piché ◽  
M. Dessureault ◽  
...  
Keyword(s):  
Biological Control ◽  
Morphological Changes ◽  
Heterobasidion Annosum ◽  
Dutch Elm Disease ◽  
Interference Microscopy ◽  
Tree Diseases ◽  
Antifungal Metabolites ◽  
Wide Range ◽  
Fungal Antagonist

Phaeotheca dimorphospora, which was first isolated from elm wood and found to be antagonistic in vitro against the Dutch elm disease pathogen Ophiostoma ulmi, was tested for antifungal activity in vitro against other tree pathogens by a variation of the agar layer technique. Phaeotheca dimorphospora produced antifungal compounds that were strongly inhibitory against a wide range of tree pathogens in addition to O. ulmi, such as Gremmeniella spp., Armillaria spp., Septoria musiva, Verticillium albo-atrum, Cylindrocladium floridanum, Phytophthora sp., Nectria galligena, and Heterobasidion annosum. Under light and interference microscopy, four types of morphological changes were observed in the pathogens tested: swelling of hyphae, production of resting spores such as chlamydospores and of sclerotia, extrusion of cytoplasm from hyphal tips, and bursting and destruction of mycelium. Chloroform-soluble antagonistic compounds were extracted that showed both fungicidal and fungistatic effects on the test organisms. Key words: Phaeotheca dimorphospora, biological control, fungal antagonist, hyphal interactions, antifungal metabolites, tree diseases.

scholarly journals Aptitude of endophytic microbes for production of novel biocontrol agents and industrial enzymes towards agro-industrial sustainability

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ayodeji O. Falade ◽  
Kayode E. Adewole ◽  
Temitope C. Ekundayo
Keyword(s):  
Plant Pathogens ◽  
Insect Pests ◽  
Biocontrol Agents ◽  
Main Body ◽  
Industrial Sectors ◽  
Industrial Sustainability ◽  
Significant Damage ◽  
Wide Range ◽  
Potential Applications ◽  
To Receive

Abstract Background Endophytes have continued to receive increased attention worldwide, probably, due to the enormous biotechnological potentials spanning through various industrial sectors. This paper outlines the biotechnological potentials of endophytes in biocontrol and industrial enzyme production, and the possible contribution towards achieving agro-industrial sustainability using published articles on endophytes in both Web of Science and Scopus (1990–2020). Main body of the abstract This review discusses the potential of endophytes to produce novel secondary metabolites with effective biocontrol activity against insect pests and plant pathogens. More so, the aptitude of endophytes for production of a wide range of enzymes with potential applications in agriculture, energy and health is discussed in this review. Furthermore, this review highlights the emerging potentials of endophytes in the production of exopolysaccharide and fatty acids. This paper also advocates the need for bioprospecting endophytes for novel biocontrol agents against termites, which are known for causing significant damage to forest and stored products. Short conclusion Exploration of endophytes for biocontrol and production of biomolecules of industrial significance could contribute significantly towards agricultural and industrial sustainability.

scholarly journals The Multiple and Versatile Roles of Aureobasidium pullulans in the Vitivinicultural Sector

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 85 ◽  
Author(s):  
Despina Bozoudi ◽  
Dimitrios Tsaltas
Keyword(s):  
Aureobasidium Pullulans ◽  
Plant Pathogens ◽  
Hydrolytic Enzymes ◽  
Essential Amino Acids ◽  
Cell Protein ◽  
Heavy Oils ◽  
Positive Role ◽  
Major Interest ◽  
Wide Range ◽  
Pharmaceutical Industries

The saprophytic yeast-like fungus Aureobasidium pullulans has been well documented for over 60 years in the microbiological literature. It is ubiquitous in distribution, being found in a variety of environments (plant surfaces, soil, water, rock surfaces and manmade surfaces), and with a worldwide distribution from cold to warm climates and wet/humid regions to arid ones. Isolates and strains of A. pullulans produce a wide range of natural products well documented in the international literature and which have been regarded as safe for biotechnological and environmental applications. Showing antagonistic activity against plant pathogens (especially post-harvest pathogens) is one of the major applications currently in agriculture of the fungus, with nutrient and space competition, production of volatile organic compounds, and production of hydrolytic enzymes and antimicrobial compounds (antibacterial and antifungal). The fungus also shows a positive role on mycotoxin biocontrol through various modes, with the most striking being that of binding and/or absorption. A. pullulans strains have been reported to produce very useful industrial enzymes, such as β-glucosidase, amylases, cellulases, lipases, proteases, xylanases and mannanases. Pullulan (poly-α-1,6-maltotriose biopolymer) is an A. pullulans trademark product with significant properties and biotechnological applications in the food, cosmetic and pharmaceutical industries. Poly (β-l-malic acid), or PMA, which is a natural biopolyester, and liamocins, a group of produced heavy oils and siderophores, are among other valuable compounds detected that are of possible biotechnological use. The fungus also shows a potential single-cell protein source capacity with high levels of nucleic acid components and essential amino acids, but this remains to be further explored. Last but not least, the fungus has shown very good biocontrol against aerial plant pathogens. All these properties are of major interest in the vitivinicultural sector and are thoroughly reviewed under this prism, concluding on the importance that A. pullulans may have if used at both vineyard and winery levels. This extensive array of properties provides excellent tools for the viticulturist/farmer as well as for the oenologist to combat problems in the field and create a high-quality wine.

scholarly journals Molecular Phylogenetic Analyses of Biological Control Strains of Trichoderma harzianum and Other Biotypes of Trichoderma spp. Associated with Mushroom Green Mold

1999 ◽  
Vol 89 (4) ◽  
pp. 308-313 ◽  
Author(s):  
M. D. Ospina-Giraldo ◽  
D. J. Royse ◽  
X. Chen ◽  
C. P. Romaine
Keyword(s):  
Biological Control ◽  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Consensus Sequence ◽  
Nuclear Ribosomal Dna ◽  
Reference Sequence ◽  
Transcriptional Unit ◽  
Trichoderma Spp ◽  
Green Mold ◽  
Wide Range

A polymerase chain reaction-amplified DNA containing the internal transcribed spacer (ITS)-1, 5.8S, and ITS-2 regions of the nuclear ribosomal DNA transcriptional unit was sequenced for 81 isolates of Trichoderma spp. associated with mushroom culture or used for biological control of plant pathogens. Phylogenetic analyses revealed that the biocontrol isolates were more closely related to an isolate of T. harzianum biotype 1 (Th1) than to the aggressive biotypes 2 and 4. Th1 has been isolated from mushroom compost but is not the cause of widespread green mold epidemics that have occurred during the last 12 years in Europe and North America. Three isolates of T. harzianum obtained from shiitake (Lentinula edodes; Shi1B and S3-96) and maitake (Grifola frondosa; Mai1) substrates were placed within the biocontrol group. We also found evidence suggesting that some isolates of T. harzianum originally identified as Th4 from Pennsylvania are more closely related to Th2 from Europe. Finally, considering the wide range in sequence distribution of our samples, we propose that the consensus sequence found in this investigation be used as the reference sequence for further studies involving the identification and taxonomy of T. harzianum.

scholarly journals Identification and Characterization of Novel Genetic Markers Associated with Biological Control Activities in Bacillus subtilis

2006 ◽  
Vol 96 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Raghavendra Joshi ◽  
Brian B. McSpadden Gardener
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Genetic Markers ◽  
Plant Pathogens ◽  
Plant Growth Promoting Rhizobacteria ◽  
Subtractive Hybridization ◽  
Pythium Ultimum ◽  
Suppressive Subtractive Hybridization ◽  
Antibiotic Biosynthesis ◽  
Wide Range

Suppressive subtractive hybridization (SSH) was used to identify genetic markers associated with biological control of plant pathogens by Bacillus subtilis. The genomes of two commercialized strains, GB03 and QST713, were compared with that of strain 168, which has no defined biocontrol capacities, to obtain a pool of DNA fragments unique to the two biocontrol strains. The sequences of 149 subtracted fragments were determined and compared with those present in GenBank, but only 80 were found to correspond to known Bacillus genes. Of these, 65 were similar to genes with a wide range of metabolic functions, including the biosynthesis of cell wall components, sporulation, and antibiotic biosynthesis. Sixteen subtracted fragments shared a high degree of similarity to sequences found in multiple B. subtilis strains with proven biocontrol capacities. Oligonucleotide primers specific to nine of these genes were developed. The targeted genes included five genes involved in antibiotic synthesis (bmyB, fenD, ituC,srfAA, and srfAB) and four additional genes (yndJ, yngG, bioA, and a hypothetical open reading frame) not previously associated with biological control. All nine markers were amplified from the commercialized B. subtilis strains GB03, QST713, and MBI600, with the exception of ituC, which was not detected in GB03. The markers also were amplified from four other B. subtilis isolates, but they were not amplified from other related Bacillus strains, including the plant growth-promoting rhizobacteria IN937a and IN937b. Sequencing of the amplified markers revealed that all seven of the isolates that scored positive for multiple markers were genotypically distinct strains. Interestingly, strains scored positive for the amplifiable markers generally were more effective at inhibiting the growth of Rhizoctonia solani and Pythium ultimum than other Bacillus isolates that lacked the markers. The potential utility of the defined genetic markers to further define the diversity, ecology, and biocontrol activities of B. subtilis are discussed.

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