scholarly journals Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium

2020 ◽  
Vol 6 (4) ◽  
pp. 263
Author(s):  
Claudia Stracquadanio ◽  
Juan Manuel Quiles ◽  
Giuseppe Meca ◽  
Santa Olga Cacciola

Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radial growth (PIRG) was calculated. The highest PIRG values were 76% and 81% (direct contact) with IMI 393899 and TS, respectively. Nondirect contact does not show inhibition on any of pathogens tested, indicating that the inhibition is not due to the secretion of volatile substances. Culture filtrates were analyzed by GC-MS and HPLC-Q-TOF-MS for the identification of volatile organic compounds (VOCs) and nonvolatile organic compounds (nVOCs), respectively. Seven classes of VOCs and 12 molecules of nVOCs were identified. These results indicate that these strains of Trichoderma had antimicrobial activities and they are potential natural sources of compounds with biological activity.

2021 ◽  
Author(s):  
Lulu Qiao ◽  
Chi Lan ◽  
Luca Capriotti ◽  
Audrey Ah-Fong ◽  
Jonatan Nino Sanchez ◽  
...  

AbstractRecent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger, and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited, and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in the pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen RNA uptake efficiency.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.


Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 600
Author(s):  
Hillary Righini ◽  
Ornella Francioso ◽  
Michele Di Foggia ◽  
Antera Martel Quintana ◽  
Roberta Roberti

Phycobiliproteins (PBPs) are proteins of cyanobacteria and some algae such as rhodophytes. They have antimicrobial, antiviral, antitumor, antioxidative, and anti-inflammatory activity at the human level, but there is a lack of knowledge on their antifungal activity against plant pathogens. We studied the activity of PBPs extracted from Arthrospiraplatensis and Hydropuntiacornea against Botrytiscinerea, one of the most important worldwide plant-pathogenic fungi. PBPs were characterized by using FT-IR and FT-Raman in order to investigate their structures. Their spectra differed in the relative composition in the amide bands, which were particularly strong in A. platensis. PBP activity was tested on tomato fruits against gray mold disease, fungal growth, and spore germination at different concentrations (0.3, 0.6, 1.2, 2.4, and 4.8 mg/mL). Both PBPs reduced fruit gray mold disease. A linear dose–response relationship was observed for both PBPs against disease incidence and H. cornea against disease severity. Pathogen mycelial growth and spore germination were reduced significantly by both PBPs. In conclusion, PBPs have the potential for being also considered as natural compounds for the control of fungal plant pathogens in sustainable agriculture.


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.


2018 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Tatsuya Ohike ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
Takashi Ano

Fifty actinomycetes were isolated from fifteen soil samples and were screened for their antagonism against fungal plant pathogens by dual culture assay, and one of the strain named AR10 was shown to be most effective in suppression of growth of plant pathogen. An antifungal compound of AR10 was extracted, and purified by TLC and HPLC. As a result of NMR and LC-MS analysis, the antifungal compound was identified as albocycline. AR10 suppressed Rhizoctonia damping-off of cucumber in infection control assay. The 16S rDNA sequence of AR10 shows high sequence similarity to those of genus Streptomyces, and the closest similarity was found in the sequence of S. lanatus NBRC 12787T with 98.7% similarity. However, the production of albocycline in Streptomyces closely related to AR10 in the phylogenetic tree has not been reported. Our finding suggests that AR10 can be a candidate for biological control agents.


Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1439-1447 ◽  
Author(s):  
Patrick D. Collopy ◽  
Richard C. Amey ◽  
Martin J. Sergeant ◽  
Michael P. Challen ◽  
Peter R. Mills ◽  
...  

In plant-pathogenic fungi, the pmk1 mitogen-activated protein kinase (MAPK) signalling pathway plays an essential role in regulating the development of penetration structures and the sensing of host-derived cues, but its role in other pathosystems such as fungal–fungal interactions is less clear. We report the use of a gene disruption strategy to investigate the pmk1-like MAPK, Lf pmk1 in the development of Lecanicillium fungicola (formerly Verticillium fungicola) infection on the cultivated mushroom Agaricus bisporus. Lf pmk1 was isolated using a degenerate PCR-based approach and was shown to be present in a single copy by Southern blot analysis. Quantitative RT-PCR showed the transcript to be fivefold upregulated in cap lesions compared with pure culture. Agrobacterium-mediated targeted disruption was used to delete a central portion of the Lf pmk1 gene. The resulting mutants showed normal symptom development as assessed by A. bisporus mushroom cap assays, sporulation patterns were normal and there were no apparent changes in overall growth rates. Our results indicate that, unlike the situation in fungal–plant pathogens, the pmk1-like MAPK pathway is not required for virulence in the fungal–fungal interaction between the L. fungicola pathogen and A. bisporus host. This observation may be of wider significance in other fungal–fungal and/or fungal–invertebrate interactions.


2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.


2020 ◽  
Author(s):  
Osakina Aron ◽  
Min Wang ◽  
Anjago Wilfred Mabeche ◽  
Batool Wajjiha ◽  
Shuai Yang ◽  
...  

AbstractArginine is an important amino acid involved in processes such as cell signal transduction, protein synthesis, and sexual reproduction. To understand the biological roles of arginine biosynthesis in pathogenic fungi, we used Cpa1, the carbamoyl phosphate synthase arginine-specific small chain subunit in Saccharomyces cerevisiae as a query to identify its ortholog in Magnaporthe oryzae genome database and named it MoCpa1. MoCpa1 is a 471-amino acid protein containing the CPSase_sm_chain domain and the GATase domain. MoCpa1 transcripts were highly expressed at the conidiation, early-infection, and late-infection stages of the fungus. Targeted deletion of MoCPA1 gene resulted in the ΔMocpa1 mutant exhibiting arginine auxotrophy on MM, confirming its role in de novo arginine biosynthesis. The ΔMocpa1 mutant presented significantly decreased sporulation with some of its conidia being defective in morphology. Furthermore, the ΔMocpa1 mutant was nonpathogenic on rice and barley leaves, which was a result of defects in appressorium-mediated penetration and restricted invasive hyphal growth within host cells. Addition of exogenous arginine partially rescued conidiation and pathogenicity defects on the barley and rice leaves, while introduction of MoCPA1 gene in ΔMocpa1 mutant fully complemented the lost phenotype. Further confocal microscopy examination revealed that MoCpa1 is localized in the mitochondria. In summary, our results demonstrate that MoCpa1-mediated arginine biosynthesis is crucial for fungal development, conidiation, appressorium formation and infection-related morphogenesis in M. oryzae, thus serving as an attractive target for mitigating obstinate fungal plant pathogens.


2019 ◽  
Vol 20 (10) ◽  
Author(s):  
Nurbailis Nurbailis ◽  
AKMAL DJAMAAN ◽  
HALIATUR RAHMA ◽  
YENNY LISWARNI

Abstract. Nurbailis, Djamaan A, Rahma H, Liswarni Y. 2019. Potential of culture filtrate from Trichoderma spp. as biofungicide to Colletotrichum gloeosporioides causing anthracnose disease in chili. Biodiversitas 20: 2915-2920. Trichoderma spp. have the potential to be used for controlling the airborne pathogenic fungi such as C. gloeosporioides. The purpose of this study was to evaluate the antifungal activity of the culture filtrate of five isolates of Trichoderma spp. (T. harzianum, T. viride, T. koningii, Trichoderma PP2, Trichoderma PP3) against C. gloeosporoides causing anthracnose disease in chili. Culture filtrate of Trichoderma spp. was produced from single culture and dual culture techniques. The design was a Completely Randomized Design with six treatments and four replications. The treatments were culture filtrate from T. harzianum, T. viride, T. koningii, Trichoderma PP2, Trichoderma PP3, and negative control (without culture filtrate from Trichoderma spp.). Parameters observed were: the diameter of the colony, colony coverage, conidial germination, and conidial density. The results of this research showed all the culture filtrate from Trichoderma spp. produced by single and dual culture techniques can inhibit the growth of C. gloeosporioides. The culture filtrate from Trichoderma PP2 and T. koningii were the most potential in inhibiting the growth, conidial density, and conidial germination of C. gloeosporioides.


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