Saravanakumar Kandasamy; Kathiresan Kandasamy
Objective: To test antioxidant property of the endophytic Trichoderma species isolated from the leaves of 12 mangroves of Andaman Nicobar Islands. Methods: Eight strains of Trichoderma species were found predominant and their crude extracts were assessed for antioxidant activity by using seven assays.Results:EMFCAS8 and other strains also showed considerable activity. Total antioxidant activity varied with the strains and it was maximum in Trichoderma Conclusions: This work concluded that mangroves are rich in endophytic Trichoderma species with potential for antioxidant activity.
Bae, Hanhong; Sicher, Richard C; Kim, Moon S; Kim, Soo-Hyung; Strem, Mary D; Melnick, Rachel L; Bailey, Bryan A
Theobroma cacao (cacao) is cultivated in tropical climates and is exposed to drought stress. The impact of the endophytic fungus Trichoderma hamatum isolate DIS 219b on cacao's response to drought was studied. Colonization by DIS 219b delayed drought-induced changes in stomatal conductance, net photosynthesis, and green fluorescence emissions. The altered expression of 19 expressed sequence tags (ESTs) (seven in leaves and 17 in roots with some overlap) by drought was detected using quantitative real-time reverse transcription PCR. Roots tended to respond earlier to drought than leaves, with the drought-induced changes in expression of seven ESTs being observed after 7 d of withholding water. Changes in gene expression in leaves were not observed until after 10 d of withholding water. DIS 219b colonization delayed the drought-altered expression of all seven ESTs responsive to drought in leaves by > or = 3 d, but had less influence on the expression pattern of the drought-responsive ESTs in roots. DIS 219b colonization had minimal direct influence on the expression of drought-responsive ESTs in 32-d-old seedlings. By contrast, DIS 219b colonization of 9-d-old seedlings altered expression of drought-responsive ESTs, sometimes in patterns opposite of that observed in response to drought. Drought induced an increase in the concentration of many amino acids in cacao leaves, while DIS 219b colonization caused a decrease in aspartic acid and glutamic acid concentrations and an increase in alanine and gamma-aminobutyric acid concentrations. With or without exposure to drought conditions, colonization by DIS 219b promoted seedling growth, the most consistent effects being an increase in root fresh weight, root dry weight, and root water content. Colonized seedlings were slower to wilt in response to drought as measured by a decrease in the leaf angle drop. The primary direct effect of DIS 219b colonization was promotion of root growth, regardless of water status, and an
Bailey, Bryan A; Strem, Mary D; Wood, Delilah
Trichoderma species are usually considered soil organisms that colonize plant roots, sometimes forming a symbiotic relationship. Recent studies demonstrate that Trichoderma species are also capable of colonizing the above ground tissues of Theobroma cacao (cacao) in what has been characterized as an endophytic relationship. Trichoderma species can be re-isolated from surface sterilized cacao stem tissue, including the bark and xylem, the apical meristem, and to a lesser degree from leaves. SEM analysis of cacao stems colonized by strains of four Trichoderma species (Trichoderma ovalisporum-DIS 70a, Trichoderma hamatum-DIS 219b, Trichoderma koningiopsis-DIS 172ai, or Trichoderma harzianum-DIS 219f) showed a preference for surface colonization of glandular trichomes versus non-glandular trichomes. The Trichoderma strains colonized the glandular trichome tips and formed swellings resembling appresoria. Hyphae were observed emerging from the glandular trichomes on surface sterilized stems from cacao seedlings that had been inoculated with each of the four Trichoderma strains. Fungal hyphae were observed under the microscope emerging from the trichomes as soon as 6h after their isolation from surface sterilized cacao seedling stems. Hyphae were also observed, in some cases, emerging from stalk cells opposite the trichome head. Repeated single trichome/hyphae isolations verified that the emerging hyphae were the Trichoderma strains with which the cacao seedlings had been inoculated. Strains of four Trichoderma species were able to enter glandular trichomes during the colonization of cacao stems where they survived surface sterilization and could be re-isolated. The penetration of cacao trichomes may provide the entry point for Trichoderma species into the cacao stem allowing systemic colonization of this tissue.
Rubio, M Belén; Quijada, Narciso M; Pérez, Esclaudys; Domínguez, Sara; Monte, Enrique; Hermosa, Rosa
Trichoderma parareesei and Trichoderma reesei (teleomorph Hypocrea jecorina) produce cellulases and xylanases of industrial interest. Here, the anamorphic strain T6 (formerly T. reesei) has been identified as T. parareesei, showing biocontrol potential against fungal and oomycete phytopathogens and enhanced hyphal growth in the presence of tomato exudates or plant cell wall polymers in in vitro assays. A Trichoderma microarray was used to examine the transcriptomic changes in T6 at 20 h of interaction with tomato plants. Out of a total 34,138 Trichoderma probe sets deposited on the microarray, 250 showed a significant change of at least 2-fold in expression in the presence of tomato plants, with most of them being downregulated. T. parareesei T6 exerted beneficial effects on tomato plants in terms of seedling lateral root development, and in adult plants it improved defense against Botrytis cinerea and growth promotion under salt stress. Time course expression patterns (0 to 6 days) observed for defense-related genes suggest that T6 was able to prime defense responses in the tomato plants against biotic and abiotic stresses. Such responses undulated, with a maximum upregulation of the jasmonic acid (JA)/ethylene (ET)-related LOX1 and EIN2 genes and the salt tolerance SOS1 gene at 24 h and that of the salicylic acid (SA)-related PR-1 gene at 48 h after T6 inoculation. Our study demonstrates that the T. parareesei T6-tomato interaction is beneficial to both partners.
Full Text Available Fusarium wilt caused by F. oxysporum f.sp. cubense is one of very damaging banana plant diseases which can cause plant death. Disease control using intensive chemical fungicides will have negative impacts on the environment and humans. Endophytic Trichoderma is one of the biological control agents which can reduce the amount of inoculum of pathogens, so it can reduce disease intensity. The objectives of this study was to assess the ability of endophytic Trichoderma in inducing plant resistance against fusarium wilt. Endophytic Trichoderma was obtained from healthy roots of banana from three regencies in Yogyakarta, namely Trichoderma harzianum.swn-1, T. harzianum.swn-2, T. harzianum.psr-1, T. asperrellum, T. gamsii, and T. koningiopsis. Research on induced resintance was conducted in the greenhouse with polybag using Completely Randomized Design with 14 treatments and 3 replications. The results showed that the ability of Trichoderma gamsii antagonism against F. oxysporum f.sp. cubense was 60.61%. T. asperellum and T. harzianum.swn-2 could suppress this disease resulted in disease intensity of 8.33% which categorize as resistant. Trichoderma harzianum.psr-1 was significantly different in stimulating plant vegetative growth. Induced resistance by using endophytic Trichoderma spp. against F. oxysporum f.sp. cubense showed increase in total phenolic compounds on the third and fourth weeks as well as peroxidase activity on the third, fourth and fifth weeks. Observation of lignification on the fifth week showed that lignification occurred in root xylem
Ma, Ying; Rajkumar, Mani; Zhang, Chang; Freitas, Helena
Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water and air. In recent years, phytoremediation assisted by bacterial endophytes has been highly recommended for cleaning up of metal polluted soils since endophytic bacteria can alleviate metal toxicity in plant through their own metal resistance system and facilitate plant growth under metal stress. Endophytic bacteria improve plant growth in metal polluted soils in two different ways: 1) directly by producing plant growth beneficial substances including solubilization/transformation of mineral nutrients (phosphate, nitrogen and potassium), production of phytohormones, siderophores and specific enzymes; and 2) indirectly through controlling plant pathogens or by inducing a systemic resistance of plants against pathogens. Besides, they also alter metal accumulation capacity in plants by excreting metal immobilizing extracellular polymeric substances, as well as metal mobilizing organic acids and biosurfactants. The present work aims to review the progress of recent research on the isolation, identification and diversity of metal resistant endophytic bacteria and illustrate various mechanisms responsible for plant growth promotion and heavy metal detoxification/phytoaccumulation/translocation in plants.
Full Text Available Using biological fertilizers and pesticides based on beneficial soil microbes in order to reduce mineral fertilizers and chemical pesticides in conventional agriculture is still a matter of debate. In this regard, a European research project seeks to elucidate the role of root-endophytic fungi and to develop molecular tools to trace and quantify these fungi in the rhizosphere and root tissue. To do this, the draft genome sequence of the biocontrol fungus Trichoderma virens (T. virens was screened for simple sequence repeats (SSRs and primers were developed for 12 distinct loci. Primers were evaluated using a global collection of ten isolates where an average of 7.42 alleles per locus was detected. Nei’s standard genetic distance ranged from 0.18 to 0.27 among the isolates, and the grand mean of haploid diversity in AMOVA analysis was 0.693 ± 0.019. Roots of tomato plants were inoculated with different strains and harvested six weeks later. Subsequent PCR amplification identified root-endophytic strains and co-colonization of roots by different strains. Markers were applied to qPCR to quantify T. virens strains in root tissue and to determine their identity using allele-specific melting curve analysis. Thus, the root-endophytic lifestyle of T. virens was confirmed, strains in roots were quantified and simultaneous colonization of roots by different strains was observed.
Full Text Available Endophytic fungi is a rich source of novel organic compounds with interesting biological activities and a high level of structural diversity. As a part of our systematic search for new bioactive lead structures and specific profiles from endophytic fungi, an endophytic fungus was isolated from roots of brotowali (Tinaspora crispa, an important medicinal plant. Colonial morphological trait and microscopic observation revealed that the endophytic fungus was Trichoderma sp. The pure fungal strain was cultivated on 7 L Potatos Dextose Broth (PDB medium under room temperature (no shaking for 8 weeks. The ethyl acetate were added to cultur medium and left overnight to stop cell growth. The culture filtrates were collected and extracted with EtOAc and then taken to evaporation. Two new lactone derivatives, 5-hydroxy-4-hydroxymethyl-2H-pyran-2-one (1 and (5-hydroxy-2-oxo-2H pyran-4-yl methyl acetate (2 were obtained from the EtOAc extracts of Trichoderma sp. Their structures were determined on the basic of spectroscopic methods including UV, IR, 1H-NMR, 13C-NMR, HMQC, and HMBC.
Ho, Ying-Ning; Huang, Chieh-Chen
An endophytic bacterium, Burkholderia cenocepacia 869T2, isolated from vetiver grass, has shown its abilities for both in planta biocontrol and plant growth promotion. Its draft genome sequence was determined to provide insights into those metabolic pathways involved in plant-beneficial activity. This is the first genome report for endophytic B. cenocepacia.
袁志林; 陈益存; 章初龙; 林福呈; 陈连庆
@@ 1 INTRODUCTION Typically,Trichoderma spp.are free-living fungi most frequently isolated from soils and have been extensively studied due to their remarkable biocontrol and plant-growth promoting capacity.There is increasing evidence that sometimes they display flexible lifestyle and penetrate epidermis of roots and act as opportunistic,avirulent plant symbiont(Harman et al.2004).Recently,a Trichoderma species living as endophyte,Trichoderma taxi C.L.Zhang et al.(2007),has been recognized.
Mei, Chuansheng; Flinn, Barry S
Endophytes are microorganisms that live within host plants for at least part of their life and do not cause apparent symptoms of diseases. In general, beneficial endophytes promote host plant growth, increase plant nutrient uptake, inhibit plant pathogen growth, reduce disease severity, and enhance tolerance to environmental stresses. As sustainable and renewable agricultural production (including current biofuel and bioenergy crops) increases in prominence, endophytic microorganisms will play important roles and offer environmentally-friendly methods to increase productivity while reducing chemical inputs. This review discusses various aspects of beneficial fungal and bacterial endophyte interactions with plants, including the physiological and molecular mechanisms by which they benefit plant performance. We also discuss the potential for genetic modification of endophytes with useful genes, which could be used to impart additional traits following inoculation with the genetically engineered endophytes. Finally, we review US-issued patents over the past decade which relate to the use of fungal and bacterial endophytes for plant growth and stress tolerance improvement.
David J Studholme
Full Text Available Trichoderma hamatum strain GD12 is unique in that it can promote plant growth, activate biocontrol against pre- and post-emergence soil pathogens and can induce systemic resistance to foliar pathogens. This study extends previous work in lettuce to demonstrate that GD12 can confer beneficial agronomic traits to other plants, providing examples of plant growth promotion in the model dicot, Arabidopsis thaliana and induced foliar resistance to Magnaporthe oryzae in the model monocot rice. We further characterize the lettuce-T. hamatum interaction to show that bran extracts from GD12 and a N-acetyl-β-D-glucosamindase-deficient mutant differentially promote growth in a concentration dependent manner, and these differences correlate with differences in the small molecule secretome. We show that GD12 mycoparasitises a range of isolates of the pre-emergent soil pathogen Sclerotinia sclerotiorum and that this interaction induces a further increase in plant growth promotion above that conferred by GD12. To understand the genetic potential encoded by T. hamatum GD12 and to facilitate its use as a model beneficial to study plant growth promotion, induced systemic resistance and mycoparasitism we present de novo genome sequence data. We compare GD12 with other published Trichoderma genomes and show that T. hamatum GD12 contains unique genomic regions with the potential to encode novel bioactive metabolites that may contribute to GD12’s agrochemically important traits.
Studholme, David J; Harris, Beverley; Le Cocq, Kate; Winsbury, Rebecca; Perera, Venura; Ryder, Lauren; Ward, Jane L; Beale, Michael H; Thornton, Chris R; Grant, Murray
Trichoderma hamatum strain GD12 is unique in that it can promote plant growth, activate biocontrol against pre- and post-emergence soil pathogens and can induce systemic resistance to foliar pathogens. This study extends previous work in lettuce to demonstrate that GD12 can confer beneficial agronomic traits to other plants, providing examples of plant growth promotion in the model dicot, Arabidopsis thaliana and induced foliar resistance to Magnaporthe oryzae in the model monocot rice. We further characterize the lettuce-T. hamatum interaction to show that bran extracts from GD12 and an N-acetyl-β-D-glucosamindase-deficient mutant differentially promote growth in a concentration dependent manner, and these differences correlate with differences in the small molecule secretome. We show that GD12 mycoparasitises a range of isolates of the pre-emergence soil pathogen Sclerotinia sclerotiorum and that this interaction induces a further increase in plant growth promotion above that conferred by GD12. To understand the genetic potential encoded by T. hamatum GD12 and to facilitate its use as a model beneficial organism to study plant growth promotion, induced systemic resistance and mycoparasitism we present de novo genome sequence data. We compare GD12 with other published Trichoderma genomes and show that T. hamatum GD12 contains unique genomic regions with the potential to encode novel bioactive metabolites that may contribute to GD12's agrochemically important traits.
Liang, Xiao-Rui; Miao, Feng-Ping; Song, Yin-Ping; Guo, Zhan-Yong; Ji, Nai-Yun
One new diterpene, trichocitrin (1), and four known secondary metabolites, nafuredin (2), 5-hydroxy-2,3-dimethyl-7-methoxychromone (3), 24-methylenecycloartanol (4) and citrostadienol (5), were isolated from the culture of marine brown alga-endophytic Trichoderma citrinoviride cf-27. Trichocitrin (1) represents the first Trichoderma-derived and furan-bearing fusicoccane diterpene, and its structure and relative configuration were identified by analysis of 1D/2D NMR and mass spectroscopic data. Compounds 1 and 2 exhibited 8.0- and 9.5-mm inhibition zones, respectively, against Escherichia coli at 20 μg/disc and 54.1 and 36.7% growth inhibition, respectively, of Prorocentrum donghaiense at 80 μg/mL.
Taghavi, Safiyh; Garafola, Craig; Monchy, Sébastien; Newman, Lee; Hoffman, Adam; Weyens, Nele; Barac, Tanja; Vangronsveld, Jaco; van der Lelie, Daniel
The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides x Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels.
Full Text Available An endophytic bacterium isolate G062 was characterized base on its molecular genetic potents, morphology, physiology, and biochemistry reactions. Analysis of 16S rDNA sequences of G062 showed the highest similarity to Paracoccus halophilus (98%. Detection of the phlD and prnC genes occurrence indicated that the bacterium had this antibiotic-like genes of Diacethylphloroglucinol (DAPG and pyrrolnitrin. The cells are rod shaped (0.59-0.89 x 1.85-3.3 µm, aerobic, Gram negative, non motile, non spore forming, positive catalase, positive oxydase, could reduce NO3 to N2, nitrogen fixing, producing siderophore and plant growth hormones-like compounds (IAA, Gibberellin, and zeatin, and solubilizing phosphate. The G062 isolate could grow on media containing 2.5% NaCl. Range of the temperature and pH growth were 15-40 and 5.0-9.5 oC, respectively. The bacterium did not cause red blood cells lysis. There was no hypersensitive response when it was injected into tobacco leaves, and it was not pathogenic against potato plantlets. Moreover, the bacterium promoted the growth of the potato plant and had high colonization ability. These results suggested that the bacterium had beneficial and good traits as biological agent candidate to promote potato plant growth.
Endophytic Trichoderma gamsii YIM PH30019: a promising biocontrol agent with hyperosmolar, mycoparasitism, and antagonistic activities of induced volatile organic compounds on root-rot pathogenic fungi of Panax notoginseng
Conclusion: The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.
Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU
Switchgrass represents a promising feedstock crop for US energy sustainability. However, its broad utilization for bioenergy requires improvements of biomass yields and stress tolerance. In this DOE funded project, we have been working on harnessing beneficial bacterial endophytes to enhance switchgrass performance and to develop a low input feedstock production system for marginal lands that do not compete with the production of food crops. We have demonstrated that one of most promising plant growth-promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize roots and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, greenhouse, as well as field conditions. Furthermore, PsJN bacterization improved growth and development of switchgrass seedlings, significantly stimulated plant root and shoot growth, and tiller number in the field, and enhanced biomass accumulation on both poor (p<0.001) and rich (p<0.05) soils, with more effective stimulation of plant growth in low fertility soil. Plant physiology measurements showed that PsJN inoculated Alamo had consistently lower transpiration, lower stomatal conductance, and higher water use efficiency in greenhouse conditions. These physiological changes may significantly contribute to the recorded growth enhancement. PsJN inoculation rapidly results in an increase in photosynthetic rates which contributes to the advanced growth and development. Some evidence suggests that this initial growth advantage decreases with time when resources are not limited such as in greenhouse studies. Additionally, better drought resistance and drought hardening were observed in PsJN inoculated switchgrass. Using the DOE-funded switchgrass EST microarray, in a collaboration with the Genomics Core Facility at the Noble Foundation, we have determined gene expression profile changes in both responsive switchgrass cv. Alamo and non-responsive cv. Cave-in-Rock (CR) following Ps
Mei, Chuansheng [IALR; Nowak, Jerzy [VPISU; Seiler, John [VPISU
Switchgrass represents a promising feedstock crop for US energy sustainability. However, its broad utilization for bioenergy requires improvements of biomass yields and stress tolerance. In this DOE funded project, we have been working on harnessing beneficial bacterial endophytes to enhance switchgrass performance and to develop a low input feedstock production system for marginal lands that do not compete with the production of food crops. We have demonstrated that one of most promising plant growth-promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize roots and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, greenhouse, as well as field conditions. Furthermore, PsJN bacterization improved growth and development of switchgrass seedlings, significantly stimulated plant root and shoot growth, and tiller number in the field, and enhanced biomass accumulation on both poor (p<0.001) and rich (p<0.05) soils, with more effective stimulation of plant growth in low fertility soil. Plant physiology measurements showed that PsJN inoculated Alamo had consistently lower transpiration, lower stomatal conductance, and higher water use efficiency in greenhouse conditions. These physiological changes may significantly contribute to the recorded growth enhancement. PsJN inoculation rapidly results in an increase in photosynthetic rates which contributes to the advanced growth and development. Some evidence suggests that this initial growth advantage decreases with time when resources are not limited such as in greenhouse studies. Additionally, better drought resistance and drought hardening were observed in PsJN inoculated switchgrass. Using the DOE-funded switchgrass EST microarray, in a collaboration with the Genomics Core Facility at the Noble Foundation, we have determined gene expression profile changes in both responsive switchgrass cv. Alamo and non-responsive cv. Cave-in-Rock (CR) following Ps
Nasaruddin, Nasaruddin; Hendarto, Hendarto; Hakkar, Andi Akbar; Agriansyah, Nursalim
Trichoderma species are able to persist on living sapwood and leaves of cacao (Theobroma cacao) in an endophytic relationship. In this research, we evaluated the ability of Trichodema asperellum introduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application of T. asperellum was 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mL T. asperellum, the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations of T. asperellum listed above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application of T. asperellum to cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches. PMID:27790069
Aline S Romão-Dumaresq
Full Text Available The sugarcane root endophyte Trichoderma virens 223 holds enormous potential as a sustainable alternative to chemical pesticides in the control of sugarcane diseases. Its efficacy as a biocontrol agent is thought to be associated with its production of chitinase enzymes, including N-acetyl-ß-D-glucosaminidases, chitobiosidases and endochitinases. We used targeted gene deletion and RNA-dependent gene silencing strategies to disrupt N-acetyl-ß-D-glucosaminidase and endochitinase activities of the fungus, and to determine their roles in the biocontrol of soil-borne plant pathogens. The loss of N-acetyl-ß-D-glucosaminidase activities was dispensable for biocontrol of the plurivorous damping-off pathogens Rhizoctonia solani and Sclerotinia sclerotiorum, and of the sugarcane pathogen Ceratocystis paradoxa, the causal agent of pineapple disease. Similarly, suppression of endochitinase activities had no effect on R. solani and S. sclerotiorum disease control, but had a pronounced effect on the ability of T. virens 223 to control pineapple disease. Our work demonstrates a critical requirement for T. virens 223 endochitinase activity in the biocontrol of C. paradoxa sugarcane disease, but not for general antagonism of other soil pathogens. This may reflect its lifestyle as a sugarcane root endophyte.
Maddau, Lucia; Cabras, Annalisa; Franceschini, Antonio; Linaldeddu, Benedetto T; Crobu, Salvatore; Roggio, Tonina; Pagnozzi, Daniela
A cork oak endophytic strain of Trichoderma citrinoviride, previously selected for its antagonistic potential against various fungal pathogens involved in oak decline, was screened for the production of bioactive secondary metabolites. From liquid culture a mixture of polypeptide antibiotics (peptaibols) belonging to the paracelsin family was isolated and characterized. This peptide mixture was purified by column chromatography and preparative TLC on silica gel, and separated by analytical HPLC. It was analysed by MALDI-TOF MS and nano-ESI-QTOF MS. Tandem mass experiments were performed to determine the amino acid sequences based on the fragmentation pattern of selected parent ions. The mixture comprised 20-residue peptides with C-terminal phenylalaninol and N-terminal acetylation. Twenty-eight amino acid sequences were identified, and amino acid exchanges were located in positions 6, 9, 12 and 17. Among them, seven sequences are new as compared to those reported in the database specifically for peptaibols and in the literature. In addition, we obtained experimental evidence suggesting the existence of non-covalent dimeric forms (homo- and hetero-) of the various peptaibol species. The peptide mixture showed strong antifungal activity toward seven important forest tree pathogens, and it was highly toxic in an Artemia salina (brine shrimp) bioassay. These results emphasize the cryptic role of endophytic fungi as a source of novel bioactive natural products and biocontrol agents.
Carvalho, T L G; Ballesteros, H G F; Thiebaut, F; Ferreira, P C G; Hemerly, A S
A wide range of rhizosphere diazotrophic bacteria are able to establish beneficial associations with plants, being able to associate to root surfaces or even endophytically colonize plant tissues. In common, both associative and endophytic types of colonization can result in beneficial outcomes to the plant leading to plant growth promotion, as well as increase in tolerance against biotic and abiotic stresses. An intriguing question in such associations is how plant cell surface perceives signals from other living organisms, thus sorting pathogens from beneficial ones, to transduce this information and activate proper responses that will finally culminate in plant adaptations to optimize their growth rates. This review focuses on the recent advances in the understanding of genetic and epigenetic controls of plant-bacteria signaling and recognition during beneficial associations with associative and endophytic diazotrophic bacteria. Finally, we propose that "soil-rhizosphere-rhizoplane-endophytes-plant" could be considered as a single coordinated unit with dynamic components that integrate the plant with the environment to generate adaptive responses in plants to improve growth. The homeostasis of the whole system should recruit different levels of regulation, and recognition between the parties in a given environment might be one of the crucial factors coordinating these adaptive plant responses.
Full Text Available Two new sesquiterpenes, microsphaeropsisin B (1 and C (2, and two new de-O-methyllasiodiplodins, (3R, 7R-7-hydroxy-de-O-methyllasiodiplodin (4 and (3R-5-oxo-de-O-methyllasiodiplodin (5, together with one new natural product (6 and twelve known compounds (3, 7–17, were isolated from the co-cultivation of mangrove endophytic fungus Trichoderma sp. 307 and aquatic pathogenic bacterium Acinetobacter johnsonii B2. Their structures, including absolute configurations, were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, Mo2(AcO4-induced circular dichroism, and comparison with reported data. All of the isolated compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. New compounds 4 and 5 exhibited potent α-glucosidase inhibitory activity with IC50 values of 25.8 and 54.6 µM, respectively, which were more potent than the positive control (acarbose, IC50 = 703.8 µM. The good results of the tested bioactivity allowed us to explore α-glucosidase inhibitors in lasiodiplodins.
Aline Silva Romão-Dumaresq
Full Text Available Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere associated with two varieties of sugarcane, a non-genetically modified (SP80-1842 variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance. For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting under two crop management (weeding and herbicide treatments. In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere. An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community's structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found
Romão-Dumaresq, Aline Silva; Dourado, Manuella Nóbrega; Fávaro, Léia Cecilia de Lima; Mendes, Rodrigo; Ferreira, Anderson; Araújo, Welington Luiz
Plant-associated fungi are considered a vast source for biotechnological processes whose potential has been poorly explored. The interactions and diversity of sugarcane, one of the most important crops in Brazil, have been rarely studied, mainly concerning fungal communities and their interactions with transgenic plants. Taking this into consideration, the purpose of this study was, based on culture dependent strategy, to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated with two varieties of sugarcane, a non-genetically modified (SP80-1842) variety and its genetically modified counterpart (IMI-1, expressing imazapyr herbicide resistance). For this, the sugarcane varieties were evaluated in three sampling times (3, 10 and 17 months after planting) under two crop management (weeding and herbicide treatments). In addition, a strain of Trichoderma virens, an endophyte isolated from sugarcane with great potential as a biological control, growth promotion and enzyme production agent, was selected for the fungal-plant interaction assays. The results of the isolation, characterization and evaluation of fungal community changes showed that the sugarcane fungal community is composed of at least 35 different genera, mostly in the phylum Ascomycota. Many genera are observed at very low frequencies among a few most abundant genera, some of which were isolated from specific plant sites (e.g., the roots or the rhizosphere). An assessment of the possible effects upon the fungal community showed that the plant growth stage was the only factor that significantly affected the community’s structure. Moreover, if transgenic effects are present, they may be minor compared to other natural sources of variation. The results of interaction studies using the Green fluorescent protein (GFP)-expressing T. virens strain T.v.223 revealed that this fungus did not promote any phenotypic changes in the host plant and was found mostly in
Full Text Available The presence of phorbol esters (PEs with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1 was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05 removed PEs with percentage losses of 96.9%–99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%–92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%–96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs.
Full Text Available Quorum sensing auto-inducers of the N-acyl homoserine lactone (AHL type produced by Gram-negative bacteria have different effects on plants including stimulation on root growth and/or priming or acquirement of systemic resistance in plants. In this communication the influence of AHL production of the plant growth promoting endophytic rhizosphere bacterium Acidovorax radicis N35 on barley seedlings was investigated. A. radicis N35 produces 3-hydroxy-C10-homoserine lactone (3-OH-C10-HSL as the major AHL compound. To study the influence of this QS autoinducer on the interaction with barley, the araI-biosynthesis gene was deleted. The comparison of inoculation effects of the A. radicis N35 wild type and the araI mutant resulted in remarkable differences. While the N35 wild type colonized plant roots effectively in microcolonies, the araI mutant occurred at the root surface as single cells. Furthermore, in a mixed inoculum the wild type was much more prevalent in colonization than the araI mutant documenting that the araI mutation affected root colonization. Nevertheless, a significant plant growth promoting effect could be shown after inoculation of barley with the wild type and the araI mutant in soil after two months cultivation. While A. radicis N35 wild type showed only a very weak induction of early defense responses in plant RNA expression analysis, the araI mutant caused increased expression of flavonoid biosynthesis genes. This was corroborated by the accumulation of several flavonoid compounds such as saponarin and lutonarin in leaves of root inoculated barley seedlings. Thus, although the exact role of the flavonoids in this plant response is not clear yet, it can be concluded, that the synthesis of AHLs by A. radicis has implications on the perception by the host plant barley and thereby contributes to the establishment and function of the bacteria-plant interaction.
Han, Shengcai; Li, Dan; Trost, Eva; Mayer, Klaus F.; Vlot, A. Corina; Heller, Werner; Schmid, Michael; Hartmann, Anton; Rothballer, Michael
Quorum sensing auto-inducers of the N-acyl homoserine lactone (AHL) type produced by Gram-negative bacteria have different effects on plants including stimulation on root growth and/or priming or acquirement of systemic resistance in plants. In this communication the influence of AHL production of the plant growth promoting endophytic rhizosphere bacterium Acidovorax radicis N35 on barley seedlings was investigated. A. radicis N35 produces 3-hydroxy-C10-homoserine lactone (3-OH-C10-HSL) as the major AHL compound. To study the influence of this QS autoinducer on the interaction with barley, the araI-biosynthesis gene was deleted. The comparison of inoculation effects of the A. radicis N35 wild type and the araI mutant resulted in remarkable differences. While the N35 wild type colonized plant roots effectively in microcolonies, the araI mutant occurred at the root surface as single cells. Furthermore, in a mixed inoculum the wild type was much more prevalent in colonization than the araI mutant documenting that the araI mutation affected root colonization. Nevertheless, a significant plant growth promoting effect could be shown after inoculation of barley with the wild type and the araI mutant in soil after 2 months cultivation. While A. radicis N35 wild type showed only a very weak induction of early defense responses in plant RNA expression analysis, the araI mutant caused increased expression of flavonoid biosynthesis genes. This was corroborated by the accumulation of several flavonoid compounds such as saponarin and lutonarin in leaves of root inoculated barley seedlings. Thus, although the exact role of the flavonoids in this plant response is not clear yet, it can be concluded, that the synthesis of AHLs by A. radicis has implications on the perception by the host plant barley and thereby contributes to the establishment and function of the bacteria-plant interaction. PMID:28018401
Nongbri, Pyniarlang L; Johnson, Joy Michal; Sherameti, Irena; Glawischnig, Erich; Halkier, Barbara Ann; Oelmüller, Ralf
The growth-promoting and root-colonizing endophyte Piriformospora indica induces camalexin and the expression of CYP79B2, CYP79B3, CYP71A13, PAD3, and WRKY33 required for the synthesis of indole-3-acetaldoxime (IAOx)-derived compounds in the roots of Arabidopsis seedlings. Upregulation of the mRNA levels by P. indica requires cytoplasmic calcium elevation and mitogen-activated protein kinase 3 but not root-hair-deficient 2, radical oxygen production, or the 3-phosphoinositide-dependent kinase 1/oxidative signal-inducible 1 pathway. Because P. indica-mediated growth promotion is impaired in cyp79B2 cyp79B3 seedlings, while pad3 seedlings-which do not accumulate camalexin-still respond to the fungus, IAOx-derived compounds other than camalexin (e.g., indole glucosinolates) are required during early phases of the beneficial interaction. The roots of cyp79B2 cyp79B3 seedlings are more colonized than wild-type roots, and upregulation of the defense genes pathogenesis-related (PR)-1, PR-3, PDF1.2, phenylalanine ammonia lyase, and germin indicates that the mutant responds to the lack of IAOx-derived compounds by activating other defense processes. After 6 weeks on soil, defense genes are no longer upregulated in wild-type, cyp79B2 cyp79B3, and pad3 roots. This results in uncontrolled fungal growth in the mutant roots and reduced performance of the mutants. We propose that a long-term harmony between the two symbionts requires restriction of root colonization by IAOx-derived compounds.
Foreman, Pamela [Los Altos, CA; Goedegebuur, Frits [Vlaardingen, NL; Van Solingen, Pieter [Naaldwijk, NL; Ward, Michael [San Francisco, CA
Described herein are novel gene sequences isolated from Trichoderma reesei. Two genes encoding proteins comprising a cellulose binding domain, one encoding an arabionfuranosidase and one encoding an acetylxylanesterase are described. The sequences, CIP1 and CIP2, contain a cellulose binding domain. These proteins are especially useful in the textile and detergent industry and in pulp and paper industry.
The fungus Trichoderma spp. on vegetables Anne Winding, National Environmental Research Institute, Roskilde, AU Trichoderma spp. is a naturally occurring fungus in soil and T. harzianum is an active ingredient in microbial pest control agents (MPCA) active against root pathogenic fungi....... The MPCA is administered to the plants by watering. The fungus establishes in the root zone and exerts its beneficial effect by general increase of resistance against pathogenic fungi. The natural occurrence of Trichoderma spp. and the fate and survival of the introduced T. harzianum on vegetables...
Yuan, Zhi-Lin; Lin, Fu-Cheng; Zhang, Chu-Long; Kubicek, Christian P
A survey of the endophytic fungal community of wild rice (Oryza granulata) in China was conducted. Two isolates recovered from healthy roots are assumed to be dark septate endophytes (DSEs). They are morphologically similar to species from the genus Harpophora and are identified as a new species, Harpophora oryzae, based on the molecular phylogeny and morphological characteristics. A neighbor-joining tree constructed from ITS-5.8S rRNA gene regions reveals that H. oryzae forms a distinctive subclade within the genus Harpophora, and is not genetically close to other species of Harpophora. Harpophora oryzae exhibits a moderate growth rate, with a frequent production of rope-like strands. It sporulates readily on artificial medium. Phialides are usually flask or bottle shaped and occur singly along hyphae or laterally and terminally on branched, hyaline to brown conidiophores, and also form whorls on metulae. Conidiophores are mostly branched with a slightly thickened wall, varying in dimensions. Conidia are one-celled and hyaline, most of them being falcate and strongly curved. The morphological differences between Harpophora spp. and Harpophora-like anamorphs representing different orders are also discussed. An in vitro inoculation test showed that H. oryzae may contribute towards improving rice (Oryza sativa L.) growth. Microscopic inspection of roots and phylogenetic placement of isolates further confirmed that H. oryzae represents a novel member of DSEs.
Schuster, André; Schmoll, Monika
Fungi of the genus Trichoderma are soilborne, green-spored ascomycetes that can be found all over the world. They have been studied with respect to various characteristics and applications and are known as successful colonizers of their habitats, efficiently fighting their competitors. Once established, they launch their potent degradative machinery for decomposition of the often heterogeneous substrate at hand. Therefore, distribution and phylogeny, defense mechanisms, beneficial as well as ...
Hardoim, Pablo R.; Hardoim, Cristiane C. P.; van Overbeek, Leonard S.; van Elsas, Jan Dirk
Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However,
Hardoim, P.R.; Hardoim, C.C.P.; Overbeek, van L.S.; Elsas, van J.D.
Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However,
Monte E; Rodríguez A; Rey M; Axpilicueta A; Gómez M I; de la Vina G; Grondona I; Llobell A
@@ The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL , a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL , has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field.
Khan, Abdul Latif; Hussain, Javid; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung
The beneficial effects of endophytes on plant growth are important for agricultural ecosystems because they reduce the need for fertilizers and decrease soil and water pollution while compensating for environmental perturbations. Endophytic fungi are a novel source of bioactive secondary metabolites; moreover, recently they have been found to produce physiologically active gibberellins as well. The symbiosis of gibberellins producing endophytic fungi with crops can be a promising strategy to overcome the adverse effects of abiotic stresses. The association of such endophytes has not only increased plant biomass but also ameliorated plant-growth during extreme environmental conditions. Endophytic fungi represent a trove of unexplored biodiversity and a frequently overlooked component of crop ecology. The present review describes the role of gibberellins producing endophytic fungi, suggests putative mechanisms involved in plant endophyte stress interactions and discusses future prospects in this field.
ZHANG Chu-long; XU Tong
@@ Seventeen species of Trichoderma, isolated from soil or tree bark from China are identified based on morphological and physiological characters, and from their phylogenetic position inferred from parsimony analyses of nucleotide sequences of the internal transcribed spacer regions of the rDNA cluster (ITS1 and 2) and partial sequences of translation elongation factor 1-alpha (tef1) . There were T. citrinoviride, T. longibrachiatum, T. sinensis in section Longibrachiatum, T. atroviride, T.koningii, T. viride, T. asperellum, T. hamatum, T. erinaceum in section Trichoderma, T.harzianum (H.lixii) , T. inhamatum, T. velutinum , T. cerinum , T. strictipile , T. spirale ,T. virens, H. nigrovirens (Trichoderma sp.) in section Pachybasium. Among them four species:T. asperellum , T. velutinum , T. cerinum , T. spirale were reported firstly in China. In addition, two suspected new taxa (Trichoderma spp.) in Trichoderma section were proposed:Trichoderma sp. 1 (ZAUT261, 4, 4A, 15A, 2C), Trichoderma sp. 2 (2B, 5, 7A, 7B, 9A).Trichoderma sp. 1 was similar to T. hamatum , but the temperature optimum for mycelial growth was lower than that of T. hamatum and the species tended to form hemisphaerical pustule with Telatively larger conidia (average length 4.6 μm × 2.8 μm). Trichoderma sp. 2 was distinguished morphologically from related species T. strigosum, T. pubescens, T. erinaceum, T. hamatum and Trichoderma sp. 1 in pustules on CMD without fertile or sterile conidiophore elongation and distinctive phialide shape, the conidiophore branches similar to T. koningii, but the conidia similar to T. viride, subglobose, conspicuously tuberculate.
ZHAO Zhi-hui; SUN Xiao-dong; YANG Rui-xiu; YANG Hong; LU Guo-zhong
@@ The protected agricultural production has become one of the fast growing and widespread cultivation technology in the north parts of China. Continuous cultivation of single crop or less rotation of crops usually resulted in the large amount of accumulation of soilborne pathogens and serious crop diseases in the greenhouse. After a few years of investigation of soilborne fungi in the north parts of China, nearly one hundred species of mictosporic fungi have been identified by the authors. Among these fungi 11species of Trichoderma have been morphologically identified, namely T. atroviride, T.aureoviride, T. citrinoviride , T. fertile, T. harzianum , T. inhamatum , T.longibrachiatum, T. parceramosum, T. reeseii, T. virens and T. viride. Trichoderm is found to be a frequently occurring genus of fungi in greenhouse soil. As an important component of effective beneficial antibiotic mycoparasites in soil Trichoderma plays an important part to regulate the balance of beneficial and harmful soilborne microorganisms.
Problemen met groene schimmel in champignon-compost blijven zich voor doen, ondanks alle genomen maatregelen. In een onderzoek van Plant Research International wordt nu getracht, via geurprofielen Trichoderma aggressivum al tijdens het doorgroeien aan te tonen.
van der Lelie, D.; Taghavi, S.; Monchy, S.; Schwender, J.; Miller, L.; Ferrieri, R.; Rogers, A.; Zhu, W.; Weyens, N.; Vangronsveld, J.; Newman, L.
Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an improved understanding of the interaction between poplar and its endophytic bacteria has the potential to provide major breakthroughs that will improve the productivity of poplar. Endophytic bacteria can improve plant growth and development in a direct or indirect way. Direct plant growth promoting mechanisms may involve nitrogen fixation, production of plant growth regulators such as auxins, cytokinins and gibberellins, and suppression of stress ethylene synthesis by 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Endophytic bacteria can indirectly benefit the plant by preventing the growth or activity of plant pathogens through competition for space and nutrients, antibiosis, production of hydrolytic enzymes, inhibition of pathogen-produced enzymes or toxins, and through systemic induction of plant defense mechanisms. Examples of applications for custom endophyte-host partnerships include improved productivity and establishment of poplar trees on marginal soils and the phytoremediation of contaminated soils and groundwater. A systems biology approach to understand the synergistic interactions between poplar and its beneficial endophytic bacteria represents an important field of research, which is facilitated by the recent sequencing of the genomes of poplar and several of its endophytic bacteria.
Well known plant production systems should be re-evaluated due to findings that the interesting metabolite might actually be produced by microbes intimately associated with the plant, so-called endophytes. Endophytes can be bacteria or fungi and they are characterized usually by the feature that they do not cause any harm to the host. Indeed, in some cases, such as mycorrhizal fungi or other growth promoting endophytes, they can be beneficial for the plant. Here some examples are reviewed where the host plant and/or endophyte metabolism can be induced by the other partner. Also, partial or complete biosynthesis pathways for plant secondary metabolites can be attributed to such endophytes. In other cases the host plant is able to metabolize substances from fungal origin. The question of the natural role of such metabolic changes for the endophyte will be briefly touched. Finally, the consequences for the use of plant cultures for secondary metabolite production is discussed.
张海燕; 张颖; 王磊; 刘凤英; 王刚
A total of 296 endophytic bacterium strains were isolated from 38 samples of healthy wheat roots collected from western area of Henan province. In vivo tests were used to acquire efficient biocon-trol strains against wheat sharp eyespot and the results showed that 13 strains could reduce significantly the incidence and severity of wheat sharp eyespot. Among endophytic bacteria isolates, strain Z8 - 15 had the best biocontrol efficacy against wheat sharp eyespot, reaching 81. 82%. Antagonistic activities against Rhizoctonia cereali and Gaeumannomyces graminis var. Tritici, and abilities to produce fungi cell wall degradation enzymes such as glucanase, chitinase, proteinase, etc, of 13 endophytic bacteria were tested on plate. The results of obvious difference between strains indicated that different biocontrol mechanisms existed among different endophytic bacteria.%从采自河南西部地区的38份健康小麦根系内分离到小麦内生细菌296株.通过活体植株筛选,从中获得的13株细菌,可显著降低小麦纹枯病的发病率和严重度,其中菌株Z8-15的生防效果最好,防效达到81.82％.在平板上测定了13个菌株对小麦纹枯病菌和小麦全蚀病菌的拮抗能力以及产生葡聚糖酶、几丁质酶和蛋白酶等真菌细胞壁降解酶的能力,发现不同菌株间差别明显,暗示不同内生生防菌株对小麦纹枯病可能具有不同的生防机制.
Quilliam, Richard S; Jones, David L
As carnivorous plants acquire substantial amounts of nutrients from the digestion of their prey, mycorrhizal associations are considered to be redundant; however, fungal root endophytes have rarely been examined. As endophytic fungi can have profound impacts on plant communities, we aim to determine the extent of fungal root colonisation of the carnivorous plant Drosera rotundifolia at two points in the growing season (spring and summer). We have used a culture-dependent method to isolate fungal endophytes and diagnostic polymerase chain reaction methods to determine arbuscular mycorrhizal fungi colonisation. All of the roots sampled contained culturable fungal root endophytes; additionally, we have provided molecular evidence that they also host arbuscular mycorrhizal fungi. Colonisation showed seasonal differences: Roots in the spring were colonised by Articulospora tetracladia, two isolates of uncultured ectomycorrhizal fungi, an unidentified species of fungal endophyte and Trichoderma viride, which was present in every plant sampled. In contrast, roots in the summer were colonised by Alatospora acuminata, an uncultured ectomycorrhizal fungus, Penicillium pinophilum and an uncultured fungal clone. Although the functional roles of fungal endophytes of D. rotundifolia are unknown, colonisation may (a) confer abiotic stress tolerance, (b) facilitate the acquisition of scarce nutrients particularly at the beginning of the growing season or (c) play a role in nutrient signalling between root and shoot.
Safinah Surya Hakim
Full Text Available Fungal endophytes are fungi that lives within plant tissues without causing apparent disease. It is also suggested that these fungi have ability to enhance plant growth and plant resistancy against pest and disease. This research is a preliminary study about root fungal endophytes in dipterocarp since there are lack research concerning about this study focus. We examined root fungal endophyte isolated from seedling of Shorea leprosula and Shorea selanica taken from Dramaga Experimental Forest, Bogor. Furthermore, we also tried to find out the fungal potential ability to solubilize phosphate and suppres fungal pathogen by in vitro assay. Surface sterilization method was used to isolated fungal endophytes from root tissues. Trichoderma spirale, Velsalceae sp., Melanconiela ellisii, Chaetosphaeria callimorpha, and Trichoderma asperellum were isolated during this study. These fungi appear to have specific association between fungal species and host plant, but no evidence of fungal order-level specificiation in S. leprosula and S. selanica. In vitro test also suggested that root fungal endophyte Trichoderma spirale and Melanconiella elisii have potential ability to solubilize inorganic phosphate. In addition, this result also present that root fungal endophyte T. spirale and T. asperellum have the potential to inhibit pathogen fungi Fusarium sp.
Druzhinina, Irina S; Shelest, Ekaterina; Kubicek, Christian P
Mycotrophic species of Trichoderma are among the most common fungi isolated from free soil, dead wood and as parasites on sporocarps of other fungi (mycoparasites). In addition, they undergo various other biotrophic associations ranging from rhizosphere colonization and endophytism up to facultative pathogenesis on such animals as roundworms and humans. Together with occurrence on a variety of less common substrata (marine invertebrates, artificial materials, indoor habitats), these lifestyles illustrate a wealthy opportunistic potential of the fungus. One tropical species, Trichoderma reesei, has become a prominent producer of cellulases and hemicellulases, whereas several other species are applied in agriculture for the biological control of phytopathogenic fungi. The sequencing of the complete genomes of the three species (T. reesei, T. virens, and T. atroviride) has led to a deepened understanding of Trichoderma lifestyle and its molecular physiology. In this review, we present the in silico predicted secretome of Trichoderma, and - in addition to the unique features of carbohydrate active enzymes - demonstrate the importance of such protein families as proteases, oxidative enzymes, and small cysteine-rich proteins, all of that received little attention in Trichoderma genetics so far. We also discuss the link between Trichoderma secretome and biology of the fungus.
Full Text Available Even highly mutually beneficial microbial-plant interactions, such as mycorrhizal- and rhizobial-plant exchanges, involve selfishness, cheating and power-struggles between the partners, which depending on prevailing selective pressures, lead to a continuum of interactions from antagonistic to mutualistic. Using manipulated grass-endophyte combinations in a five year common garden experiment, we show that grass genotypes and genetic mismatches constrain genetic combinations between the vertically (via host seeds transmitted endophytes and the out-crossing host, thereby reducing infections in established grass populations. Infections were lost in both grass tillers and seedlings in F(1 and F(2 generations, respectively. Experimental plants were collected as seeds from two different environments, i.e., meadows and nearby riverbanks. Endophyte-related benefits to the host included an increased number of inflorescences, but only in meadow plants and not until the last growing season of the experiment. Our results illustrate the importance of genetic host specificity and trans-generational maternal effects on the genetic structure of a host population, which act as destabilizing forces in endophyte-grass symbioses. We propose that (1 genetic mismatches may act as a buffering mechanism against highly competitive endophyte-grass genotype combinations threatening the biodiversity of grassland communities and (2 these mismatches should be acknowledged, particularly in breeding programmes aimed at harnessing systemic and heritable endophytes to improve the agriculturally valuable characteristics of cultivars.
Jucimar Jorgeane de Souza; Ivo José Curcino Vieira; Edson Rodrigues-Filho; Raimundo Braz-Filho
This work reviews the production of terpenoids by endophytic fungi and their biological activities, in period of 2006 to 2010. Sixty five sesquiterpenes, 45 diterpenes, five meroterpenes and 12 other terpenes, amounting to 127 terpenoids were isolated from endophytic fungi.
de Souza, Jucimar Jorgeane; Vieira, Ivo José Curcino; Rodrigues-Filho, Edson; Braz-Filho, Raimundo
This work reviews the production of terpenoids by endophytic fungi and their biological activities, in period of 2006 to 2010. Sixty five sesquiterpenes, 45 diterpenes, five meroterpenes and 12 other terpenes, amounting to 127 terpenoids were isolated from endophytic fungi.
Doni, Febri; Isahak, Anizan; Che Mohd Zain, Che Radziah; Wan Yusoff, Wan Mohtar
Trichoderma spp., a known beneficial fungus is reported to have several mechanisms to enhance plant growth. In this study, the effectiveness of seven isolates of Trichoderma spp. to promote growth and increase physiological performance in rice was evaluated experimentally using completely randomized design under greenhouse condition. This study indicated that all the Trichoderma spp. isolates tested were able to increase several rice physiological processes which include net photosynthetic rate, stomatal conductance, transpiration, internal CO2 concentration and water use efficiency. These Trichoderma spp. isolates were also able to enhance rice growth components including plant height, leaf number, tiller number, root length and root fresh weight. Among the Trichoderma spp. isolates, Trichoderma sp. SL2 inoculated rice plants exhibited greater net photosynthetic rate (8.66 μmolCO2 m(-2) s(-1)), internal CO2 concentration (336.97 ppm), water use efficiency (1.15 μmoCO2/mmoH2O), plant height (70.47 cm), tiller number (12), root length (22.5 cm) and root fresh weight (15.21 g) compared to the plants treated with other Trichoderma isolates tested. We conclude that beneficial fungi can be used as a potential growth promoting agent in rice cultivation.
Zhao, J; Shan, T; Mou, Y; Zhou, L
Plant endophytic fungi are an important and novel resource of natural bioactive compounds with their potential applications in agriculture, medicine and food industry. In the past two decades, many valuable bioactive compounds with antimicrobial, insecticidal, cytotoxic, and anticancer activities have been successfully discovered from endophytic fungi. During the long period of co-evolution, a friendly relationship was formed between each endophyte and its host plant. Some endophytes have the ability to produce the same or similar bioactive compounds as those originated from their host plants. This review mainly deals with the research progress on endophytic fungi for producing plant-derived bioactive compounds such as paclitaxel, podophyllotoxin, camptothecine, vinblastine, hypericin, and diosgenin. The relations between endophytic fungi and their host plants, biological activities and action mechanisms of these compounds from endophytic fungi, some available strategies for efficiently promoting production of these bioactive compounds, as well as their potential applications in the future will also be discussed. It is beneficial for us to better understand and take advantage of plant endophytic fungi.
Xuezhu Zhu; Xue Ni; Michael Gatheru Waigi; Juan Liu; Kai Sun; Yanzheng Gao
Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of pl...
Strakowska, Judyta; Błaszczyk, Lidia; Chełkowski, Jerzy
The degradation of native cellulose to glucose monomers is a complex process, which requires the synergistic action of the extracellular enzymes produced by cellulolytic microorganisms. Among fungi, the enzymatic systems that can degrade native cellulose have been extensively studied for species belonging to the genera of Trichoderma. The majority of the cellulolytic enzymes described so far have been examples of Trichoderma reesei, extremely specialized in the efficient degradation of plant cell wall cellulose. Other Trichoderma species, such as T. harzianum, T. koningii, T. longibrachiatum, and T. viride, known for their capacity to produce cellulolytic enzymes, have been isolated from various ecological niches, where they have proved successful in various heterotrophic interactions. As saprotrophs, these species are considered to make a contribution to the degradation of lignocellulosic plant material. Their cellulolytic potential is also used in interactions with plants, especially in plant root colonization. However, the role of cellulolytic enzymes in species forming endophytic associations with plants or in those existing in the substratum for mushroom cultivation remains unknown. The present review discusses the current state of knowledge about cellulolytic enzymes production by Trichoderma species and the encoding genes, as well as the involvement of these proteins in the lifestyle of Trichoderma.
Gong, B; Yao, X H; Zhang, Y Q; Fang, H Y; Pang, T C; Dong, Q L
Fungal endophytes live in the inner tissues of Clerodendrum inerme and may be significant resources for new chemicals in drug discovery. A total of 242 endophytic fungi were recovered from 602 sample segments of C. inerme; 66 were purified. The 66 fungi belonging to 16 taxa and 11 genera (Alternaria, Nigrospora, Bartalinia, Pestalotiopsis, Fusarium, Mycoleptodiscus, Trichoderma, Phomopsis, Diaporthe, Lasiodiplodia, and Curvularia) were identified by morphological characteristics and fungal internal transcribed spacer sequences. The most abundant genera were Alternaria and Lasiodiplodia. Some of the endophytes exhibited tissue specificity. The colonization frequencies of endophytes in the stems were evidently higher than those in the roots and leaves. The crude ethyl acetate extracts were tested against 6 endophytes isolated from C. inerme. Three of 10 (33.3%) endophytes, which were identified as Phomopsis sp, Curvularia sp, and Mycoleptodiscus sp, displayed distinct antifungal activity against ≥3 tested fungi. To our knowledge, this is the first report of an endophytic community associated with C. inerme in China and its antifungal activity in vitro.
Shukla, Nandani; Awasthi, R P; Rawat, Laxmi; Kumar, J
Rice is one of the most important food crops drastically affected by drought in lowland rice ecosystems. In the present study, the impact of drought tolerant isolates of endophytic fungus Trichoderma harzianum on rice response to drought was investigated. Out of 43 Trichoderma isolates studied, only five isolates viz., Th 56, Th 69, Th 75, Th 82 and Th 89 were selected to be drought tolerant as these were able to colonize well on cow dung at low moisture content of 10-20 percent, though two isolates, Th 56 and Th 75, grew even at 5 percent moisture content. Trichoderma-colonized rice seedlings were slower to wilt in response to drought. Colonization delayed drought induced changes like stomatal conductance, net photosynthesis and leaf greenness. Drought conditions varying from 3 to 9 days of withholding water led to an increase in the concentration of many stress induced metabolites in rice leaves and decrease of MSI, while Trichoderma colonization caused a decrease in proline, MDA and H₂O₂ contents, and increase in phenolics concentration and MSI. Among test isolates, Th 56 induced maximum drought tolerance as treated plants recorded only 20-40 percent wilting even at 9 DDS. With or without exposure to drought, colonization by Trichoderma promoted seedling growth, with Th 56 giving the most consistent effect. The primary direct effect of Trichoderma colonization was promotion of root growth, regardless of water status, which caused delay in the drought responses of rice plants.
Keswani, Chetan; Mishra, Sandhya; Sarma, Birinchi Kumar; Singh, Surya Pratap; Singh, Harikesh Bahadur
Recent shift in trends of agricultural practices from application of synthetic fertilizers and pesticides to organic farming has brought into focus the use of microorganisms that carryout analogous function. Trichoderma spp. is one of the most popular genera of fungi commercially available as a plant growth promoting fungus (PGPF) and biological control agent. Exploitation of the diverse nature of secondary metabolites produced by different species of Trichoderma augments their extensive utility in agriculture and related industries. As a result, Trichoderma has achieved significant success as a powerful biocontrol agent at global level. The endorsement of Trichoderma spp. by scientific community is based on the understanding of its mechanisms of action against a large set of fungal, bacterial and in certain cases viral infections. However, it is still an agnostic view that there could be any single major mode of operation, although it is argued that all mechanisms operate simultaneously in a synchronized fashion. The central idea behind this review article is to emphasize the potentiality of applications of target specific secondary metabolites of Trichoderma for controlling phytopathogens as a substitute of commercially available whole organism formulations. With the aim to this point, we have compiled an inclusive list of secondary metabolites produced by different species of Trichoderma and their applications in diverse areas with the major emphasis on agriculture. Outlining the importance and diverse activities of secondary metabolites of Trichoderma besides its relevance to agriculture would generate greater understanding of their other important and beneficial applications apart from target specific biopesticides.
Mastouri, Fatemeh; Björkman, Thomas; Harman, Gary E
Trichoderma spp. are endophytic plant symbionts that are widely used as seed treatments to control diseases and to enhance plant growth and yield. Although some recent work has been published on their abilities to alleviate abiotic stresses, specific knowledge of mechanisms, abilities to control multiple plant stress factors, their effects on seed and seedlings is lacking. We examined the effects of seed treatment with T. harzianum strain T22 on germination of seed exposed to biotic stress (seed and seedling disease caused by Pythium ultimum) and abiotic stresses (osmotic, salinity, chilling, or heat stress). We also evaluated the ability of the beneficial fungus to overcome physiological stress (poor seed quality induced by seed aging). If seed were not under any of the stresses noted above, T22 generally had little effect upon seedling performance. However, under stress, treated seed germinated consistently faster and more uniformly than untreated seeds whether the stress was osmotic, salt, or suboptimal temperatures. The consistent response to varying stresses suggests a common mechanism through which the plant-fungus association enhances tolerance to a wide range of abiotic stresses as well as biotic stress. A common factor that negatively affects plants under these stress conditions is accumulation of toxic reactive oxygen species (ROS), and we tested the hypothesis that T22 reduced damages resulting from accumulation of ROS in stressed plants. Treatment of seeds reduced accumulation of lipid peroxides in seedlings under osmotic stress or in aged seeds. In addition, we showed that the effect of exogenous application of an antioxidant, glutathione, or application of T22, resulted in a similar positive effect on seed germination under osmotic stress or in aged seed. This evidence supports the model that T. harzianum strain T22 increases seedling vigor and ameliorates stress by inducing physiological protection in plants against oxidative damage.
Sara R Robertson
Full Text Available Surface-adherent biofilm growth is a common trait of bacteria and other microorganisms in nature. Within biofilms, organisms are present in high density and are enmeshed in an organic matrix containing polysaccharides and other molecules. The close proximity of organisms within biofilms facilitates microbial interactions and signaling, including many metabolic processes in which consortia rather than individual organisms participate. Biofilm growth also enables microorganisms to withstand chemical and biological stresses. Here, we review some current literature and document representative beneficial aspects of biofilms using examples from wastewater treatment, microbial fuel cells, biological repair (biocementation of stonework, and biofilm protection against Candida albicans infections. Finally, we address a chemical ecology strategy whereby desired microbial succession and beneficial biofilm formation can be encouraged via manipulation of culture conditions and bacterial signaling.
AMIN, NUR; La Daha; Nasruddin, Andi; Junaed, M; Iqbal, Andi
Downy mildew is a major disease of maize caused by the fungus Peronosclerospora spp., widely distributed in all corn production centers in Indonesia. The disease can cause considerable losses; even total losses have been reported occurring on susceptible varieties. The purpose of the research was to determine the effectiveness of some isolates of endophytic fungi for the control of downy mildew on maize. The study consisted of four isolate treatments: Aspergillus spp., Trichoderma spp, Beauv...
Ofek-Lalzar, Maya; Gur, Yonatan; Ben-Moshe, Sapir; Sharon, Or; Kosman, Evsey; Mochli, Elad; Sharon, Amir
Endophytes have profound impacts on plants, including beneficial effects on agriculturally important traits. We hypothesized that endophytes in wild plants include beneficial endophytes that are absent or underrepresented in domesticated crops. In this work, we studied the structure of endophyte communities in wheat-related grasses, Triticum dicoccoides and Aegilops sharonensis, and compared it to an endophyte community from wheat (T. aeastivum). Endophytes were isolated by cultivation and by cultivation-independent methods. In total, 514 intergenic spacer region sequences from single cultures were analyzed. Categorization at 97% sequence similarity resulted in 67 operational taxonomic units (OTUs) that were evenly distributed between the different plant species. A narrow core community of Alternaria spp. was found in all samples, but each plant species also contained a significant portion of unique endophytes. The cultivation-independent analysis identified a larger number of OTUs than the cultivation method, half of which were singletons or doubletons. For OTUs with a relative abundance >0.5%, similar numbers were obtained by both methods. Collectively, our data show that wild grass relatives of wheat contain a wealth of taxonomically diverse fungal endophytes that are not found in modern wheat, some of which belong to taxa with known beneficial effects.
Ardanov, Pavlo; Sessitsch, Angela; Häggman, Hely; Kozyrovska, Natalia; Pirttilä, Anna Maria
Plant inoculation with endophytic bacteria that normally live inside the plant without harming the host is a highly promising approach for biological disease control. The mechanism of resistance induction by beneficial bacteria is poorly understood, because pathways are only partly known and systemic responses are typically not seen. The innate endophytic community structures change in response to external factors such as inoculation, and bacterial endophytes can exhibit direct or indirect antagonism towards pathogens. Earlier we showed that resistance induction by an endophytic Methylobacterium sp. in potato towards Pectobacterium atrosepticum was dependent on the density of the inoculum, whereas the bacterium itself had no antagonistic activity. To elucidate the role of innate endophyte communities in plant responses, we studied community changes in both in vitro and greenhouse experiments using various combinations of plants, endophyte inoculants, and pathogens. Induction of resistance was studied in several potato (Solanum tuberosum L.) cultivars by Methylobacterium sp. IMBG290 against the pathogens P. atrosepticum, Phytophthora infestans and Pseudomonas syringae pv. tomato DC3000, and in pine (Pinus sylvestris L.) by M. extorquens DSM13060 against Gremmeniella abietina. The capacities of the inoculated endophytic Methylobacterium spp. strains to induce resistance were dependent on the plant cultivar, pathogen, and on the density of Methylobacterium spp. inoculum. Composition of the endophyte community changed in response to inoculation in shoot tissues and correlated with resistance or susceptibility to the disease. Our results demonstrate that endophytic Methylobacterium spp. strains have varying effects on plant disease resistance, which can be modulated through the endophyte community of the host.
Full Text Available Some Trichoderma strains can persist in ecosystems with high concentrations of heavy metals. The aim of this research was to examine the variability of Trichoderma strains isolated from different ecosystems, based on their morphological properties and restriction analysis of ITS fragments. The fungal growth was tested on potato dextrose agar, amended with Cu(II concentrations ranging from 0.25 to 10 mmol/l, in order to identify copper-resistant strains. The results indicate that some isolated strains of Trichoderma sp. show tolerance to higher copper concentrations. Further research to examine the ability of copper bioaccumulation by tolerant Trichoderma strains is needed. [Projekat Ministarstva nauke Republike Srbije, br. TR 31080 i br. III 43010
Salazar-Badillo, Fatima Berenice; Sánchez-Rangel, Diana; Becerra-Flora, Alicia; López-Gómez, Miguel; Nieto-Jacobo, Fernanda; Mendoza-Mendoza, Artemio; Jiménez-Bremont, Juan Francisco
Plants are associated with a wide range of microorganisms throughout their life cycle, and some interactions result on plant benefits. Trichoderma species are plant beneficial fungi that enhance plant growth and development, contribute to plant nutrition and induce defense responses. Nevertheless, the molecules involved in these beneficial effects still need to be identify. Polyamines are ubiquitous molecules implicated in plant growth and development, and in the establishment of plant microbe interactions. In this study, we assessed the polyamine profile in Arabidopsis plants during the interaction with Trichoderma virens and Trichoderma atroviride, using a system that allows direct plant-fungal contact or avoids their physical interaction (split system). The plantlets that grew in the split system exhibited higher biomass than the ones in direct contact with Trichoderma species. After 3 days of interaction, a significant decrease in Arabidopsis polyamine levels was observed in both systems (direct contact and split). After 5 days of interaction polyamine levels were increased. The highest levels were observed with T. atroviride (split system), and with T. virens (direct contact). The expression levels of Arabidopsis ADC1 and ADC2 genes during the interaction with the fungi were also assessed. We observed a time dependent regulation of ADC1 and ADC2 genes, which correlates with polyamine levels. Our data show an evident change in polyamine profile during Arabidopsis - Trichoderma interaction, accompanied by evident alterations in plant root architecture. Polyamines could be involved in the changes undergone by plant during the interaction with this beneficial fungus.
Full Text Available Medicinal and aromatic plants are superorganisms like all plant species- naturally colonized by bacteria, fungi and protists. Micropropagated plants are facing different challenges under in vitro and ex vitro conditions: Mixotrophic growth under low light conditions on artificial nutrient media, poor gas exchange in small vessels, abiotic stress, bad rooting, transplanting stress, low survival rate during acclimatization in greenhouse. The use of endophytes in micropropagation can improve plant growth, yield, and health and induce tolerance to abiotic and biotic stress. A tool for the use of competent endophytes in micropropagation under in vitro and ex vitro conditions is “biotization” of plantlets with useful bacterial and fungal inocula. Fungal inocula which are used commercially are e.g. arbuscular mycorrhizal fungi in form of spores and extraradical mycelium on different carrier materials like expanded clay, vermiculite, sand or peat. Furthermore representatives of the root fungal genus Trichoderma are applied as spores formulated in powder. Plantgrowth promoting rhizobacteria of the important genera Bacillus, Pseudomonas, Azospirillum and Azotobacter in form of lyophilised endospores/bacterial cells in powder or liquid formulation are also available on the market.
Fungal endophytes are quite common in nature and some of them have been shown to have adverse effects against insects, nematodes, and plant pathogens. An introduction to fungal endophytes will be presented, followed by a discussion of research aimed at introducing Beauveria bassiana as a fungal endo...
Jucimar Jorgeane de Souza
Full Text Available This work reviews the production of terpenoids by endophytic fungi and their biological activities, in period of 2006 to 2010. Sixty five sesquiterpenes, 45 diterpenes, five meroterpenes and 12 other terpenes, amounting to 127 terpenoids were isolated from endophytic fungi.
Li, Yongchao; Yang, Jing; Zhou, Xiuren; Zhao, Wenen; Jian, Zaiyou
Endophytic fungi of inner root bark of Taxus wallichiana var. mairei were investigated in order to find endophytes producing 10-DABIII (10-deacetyl baccatin III). Purified colonies were cultured in potato dextrose broth (PDB), and then the organic extracts from fungi were analyzed with HPLC, LC-MS, and (1)H NMR. Of 102 fungal endophytes isolated from the inner root bark, only one strain named IRB54 can yield 10-DABIII but no taxol and baccatin III. In PDB culture medium, its productivity was 187.564 ug/l. Based on its morphological characteristics and molecular data, the IRB54 strain was identified as Trichoderma sp. The isolation of the fungus IRB54 yielding 10-DABIII will provide an alternative resource to manufacture taxol/taxotere via semi-synthesis and some useful clues for improving the understanding of taxane synthesis evolution.
Full Text Available Inconspicuous basidiomycetes from the order Sebacinales are known to be involved in a puzzling variety of mutualistic plant-fungal symbioses (mycorrhizae, which presumably involve transport of mineral nutrients. Recently a few members of this fungal order not fitting this definition and commonly referred to as 'endophytes' have raised considerable interest by their ability to enhance plant growth and to increase resistance of their host plants against abiotic stress factors and fungal pathogens. Using DNA-based detection and electron microscopy, we show that Sebacinales are not only extremely versatile in their mycorrhizal associations, but are also almost universally present as symptomless endophytes. They occurred in field specimens of bryophytes, pteridophytes and all families of herbaceous angiosperms we investigated, including liverworts, wheat, maize, and the non-mycorrhizal model plant Arabidopsis thaliana. They were present in all habitats we studied on four continents. We even detected these fungi in herbarium specimens originating from pioneering field trips to North Africa in the 1830s/40s. No geographical or host patterns were detected. Our data suggest that the multitude of mycorrhizal interactions in Sebacinales may have arisen from an ancestral endophytic habit by specialization. Considering their proven beneficial influence on plant growth and their ubiquity, endophytic Sebacinales may be a previously unrecognized universal hidden force in plant ecosystems.
Weiss, Michael; Sýkorová, Zuzana; Garnica, Sigisfredo; Riess, Kai; Martos, Florent; Krause, Cornelia; Oberwinkler, Franz; Bauer, Robert; Redecker, Dirk
Inconspicuous basidiomycetes from the order Sebacinales are known to be involved in a puzzling variety of mutualistic plant-fungal symbioses (mycorrhizae), which presumably involve transport of mineral nutrients. Recently a few members of this fungal order not fitting this definition and commonly referred to as 'endophytes' have raised considerable interest by their ability to enhance plant growth and to increase resistance of their host plants against abiotic stress factors and fungal pathogens. Using DNA-based detection and electron microscopy, we show that Sebacinales are not only extremely versatile in their mycorrhizal associations, but are also almost universally present as symptomless endophytes. They occurred in field specimens of bryophytes, pteridophytes and all families of herbaceous angiosperms we investigated, including liverworts, wheat, maize, and the non-mycorrhizal model plant Arabidopsis thaliana. They were present in all habitats we studied on four continents. We even detected these fungi in herbarium specimens originating from pioneering field trips to North Africa in the 1830s/40s. No geographical or host patterns were detected. Our data suggest that the multitude of mycorrhizal interactions in Sebacinales may have arisen from an ancestral endophytic habit by specialization. Considering their proven beneficial influence on plant growth and their ubiquity, endophytic Sebacinales may be a previously unrecognized universal hidden force in plant ecosystems.
R Abass Tolulope
Full Text Available Background: Endophytes represent a promising source of biologically active metabolites for pharmaceutical and agricultural applications. Objective: This study was aimed to investigate the endophytic fungi diversity and the antimicrobial potential of three popular medicinal plants (Alstonia boonei-Ahun, Enantia chlorantha-Awopa and Kigelia africana-Pandoro that have ethnobotanical history in Nigeria. Materials and Methods: The stem barks were used for isolation of endophytic fungi and fermented, and the cell free fermentation broths were subjected to antimicrobial screening against six human pathogens; Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and Candida albicans by using standard agar well diffusion method. Results: A total of ten endophytic fungi were isolated from the stem bark of the plants. Seven of these fungi were identified, which include; Aspergillus niger, Macrophomina spp., Trichoderma spp. and four different Penicillium species, while three of the isolated endophytes remained unknown. Furthermore, nine of the isolated endophytes showed potential antimicrobial activity against at least one of the six tested pathogens. Conclusion: This study shows that endophytic fungi inhabiting the inner tissue of medicinal plants studied may be the source of the curative properties of the plants.
W M M S Bandara; Gamini Seneviratne; S A Kulasooriya
Plants benefit extensively by harbouring endophytic microbes. They promote plant growth and confer enhanced resistance to various pathogens. However, the way the interactions among endophytes influence the plant productivity has not been explained. Present study experimentally showed that endophytes isolated from rice (Oryza sativa) used as the test plant produced two types of interactions; biofilms (bacteria attached to mycelia) and mixed cultures with no such attachments. Acidity, as measured by pH in cultures with biofilms was higher than that of fungi alone, bacteria alone or the mixed cultures. Production of indoleacetic acid like substances (IAAS) of biofilms was higher than that of mixed cultures, fungi or bacteria. Bacteria and fungi produced higher quantities of IAAS than mixed cultures. In mixed cultures, the potential of IAAS production of resident microbes was reduced considerably. There was a negative relationship between IAAS and pH of the biofilms, indicating that IAAS was the main contributor to the acidity. However, such a relationship was not observed in mixed cultures. Microbial acid production is important for suppressing plant pathogens. Thus the biofilm formation in endophytic environment seems to be very important for healthy and improved plant growth. However, it is unlikely that an interaction among endophytes takes place naturally in the endophytic environment, due to physical barriers of plant tissues. Further, critical cell density dependant quorum sensing that leads to biofilm formation may not occur in the endophytic environment as there is a limited space. As such in vitro production and application of beneficial biofilmed inocula of endophytes are important for improved plant production in any agro-ecosystem. The conventional practice of plant inoculation with monocultures or mixed cultures of effective microbes may not give the highest microbial effect, which may only be achieved by biofilm formation.
Jaklitsch, W.M.; Samuels, G.J.; Ismaiel, A.; Voglmayr, H.
Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13 phylogenet
Repas, T.; Germida, J.; Kaminskyj, S.
Fungal endophytes colonize host plants without causing disease. Some endophytes confer plant tolerance to harsh environments. One such endophyte, Trichoderma harzianum strain TSTh20-1, was isolated from a plant growing on Athabasca oil sand tailings. Tailing sands are a high volume waste product from oil sand extraction that the industry is required to remediate. Tailing sands are low in organic carbon and mineral nutrients, and are hydrophobic due to residual polyaromatic hydrocarbons. Typically, tailing sands are remediated by planting young trees in large quantities of mulch plus mineral fertilizer, which is costly and labour intensive. In greenhouse trials, TSTh20-1 supports growth of tomato seedlings on tailing sands without fertilizer. The potential use of TSTh20-1 in combination with native grasses and forbs to remediate under field conditions is being assessed. Twenty-three commercially available plant species are being screened for seed germination and growth on tailing sands in the presence of TSTh20-1. The best candidates from this group will be used in greenhouse and small scale field trials. Potential mechanisms that contribute to endophyte-induced plant growth promotion, such as plant hormone production, stress tolerance, mineral solubilization, and uptake are also being assessed. As well, TSTh20-1 appears to be remarkably frugal in its nutrient requirements and the possibility that this attribute is characteristic of other plant-fungal endophytes from harsh environments is under study.
Rafael de Felício
Full Text Available Abstract Marine environment is one of the most important sources regarding natural products research. Besides, marine microorganisms have been denominated as a talented natural source for discovery of new leads. Although the association of macroalgae and fungi has been described regarding ecological issues, there is a lack of studies about marine seaweed endophytic fungi. In this context, the goal of this study was to evaluate cytotoxic, antifungal and antibacterial activities of endophytic fungi isolated from the Brazilian marine seaweed Bostrychia tenella (J.V. Lamouroux J. Agardh (Ceramiales, Rhodophyta. Forty-five endophytic microorganism strains were isolated from B. tenella. Crude extracts and organic fractions of ten selected strains were obtained after growth in rice medium. Samples were evaluated for cytotoxicity, antifungal and antibacterial assays. Penicillium strains showed positive results in a diversity of assays, and other five strains were active in at least one test. In addition, cytochalasin D was isolated from Xylaria sp. This alga is composed of a microbiological potential, since its endophytic strains exhibited remarkable biological properties. Moreover, cytochalasin D isolation has confirmed chemical potential of marine endophytic strains. This is the first study in which cultured fungi isolates from the Brazilian macroalga B. tenella were evaluated concerning biological properties. Results corroborated that this species could be a pharmaceutical source from marine environment. Furthermore, Acremonium implicatum is being firstly described as marine endophyte and Xylaria sp., Trichoderma atroviride and Nigrospora oryzae as marine seaweed endophytes. Thus, this work reports the first study relating detailed isolation, cultivation and biological evaluation (cytotoxic, antifungal and antibacterial of endophytes Penicillium decaturense and P. waksmanii from the Brazilian marine red alga B. tenella. We are also reporting the
Yiing Yng Chow
Full Text Available This study aimed to establish the colonization behavior and proliferation potential of three endophytes and one pathogen Ganoderma boninense (Gb introduced into oil palm ramets (host model. The endophytes selected were Diaporthe phaseolorum (WAA02, Trichoderma asperellum (T2, and Penicillium citrinum (BTF08. Ramets were first inoculated with 100 mL of fungal cells (106 cfu mL−1 via soil drenching. For the next 7 days, ramets were sampled and subjected to three different assays to detect and identify fungal colonization, and establish their proliferation potential in planta. Plate assay revealed the presence of endophytes in root, stem and leaf tissues within 7 days after inoculation. Polymerase Chain Reaction (PCR detected and identified the isolates from the plant tissues. The ergosterol assay (via high-performance liquid chromatography, HPLC confirmed the presence of endophytes and Gb in planta. The increase in ergosterol levels throughout 49 days was however insignificant, suggesting that proliferation may be absent or may occur very slowly in planta. This study strongly suggests that the selected endophytes could colonize the host upon inoculation, but proliferation occurs at a slower rate, which may subsequently influence the biocontrol expression of endophytes against the pathogen.
Ruocco M; Kip N; P J G M de Wit; Lorito M; Lanzuise S; Woo S L; Ambrosino P; Marra R; Turrà D; Gigante S; Formisno E; Scala F
@@ The molecular basis of Trichoderma -plant interaction is very complex and still not completely understood. The colonization of the root system by rhizosphere competent strains of Trichoderma results in increased development of root/aerial systems, in improved yields and in plant disease control.Other beneficial effects, such as the induction of plant systemic resistance, have also been described.To understand the mechanisms involved we are using different approaches, including the making of transformants expressing genes that encode for compounds able to affect plant response to pathogens.Trichoderma transformants carrying the avirulence gene Avr4 from Cladosporium fulvum under the control of constitutive and inducible promoters were obtained and tested on tomato plants having the Cf4 resistance gene. Necrosis and suberification zones, similar to the symptoms appearing during Cladosporium-tomato interaction, were found when the roots of the Cf4 plants were treated with Avr4-Trichoderma. This demonstrates that selected Trichoderma strains are able to transfer to the plant molecules that may deeply affect metabolism, disease resistance etc. Therefore, these beneficial fungi can be regarded as biotechnological tools to provide a variety of crops with useful compounds.Moreover, in in vitro competition assays the transformants were found to be more effective as antagonists against Alternaria alternata than the wild type. Trichoderma sends a variety of biochemical signals to the plants including avirulence molecules; therefore the presence of avr-like proteins in the fungus proteome was investigated. Proteome analysis has permitted us to isolate and sequence many proteins potentially having this function. From the extraeellular protein extracts, we have purified and sequenced a protein with structural characteristics similar to Avr4 of C. fulvum.The protein, Hytra1, was found to be a hydrophobin with chitin binding activity, the typical 8cysteine residues, and 4
Alonso-Ramírez, Ana; Poveda, Jorge; Martín, Ignacio; Hermosa, Rosa; Monte, Enrique; Nicolás, Carlos
Trichoderma is a soil-borne fungal genus that includes species with a significant impact on agriculture and industrial processes. Some Trichoderma strains exert beneficial effects in plants through root colonization, although little is known about how this interaction takes place. To better understand this process, the root colonization of wild-type Arabidopsis and the salicylic acid (SA)-impaired mutant sid2 by a green fluorescent protein (GFP)-marked Trichoderma harzianum strain was followed under confocal microscopy. Trichoderma harzianum GFP22 was able to penetrate the vascular tissue of the sid2 mutant because of the absence of callose deposition in the cell wall of root cells. In addition, a higher colonization of sid2 roots by GFP22 compared with that in Arabidopsis wild-type roots was detected by real-time polymerase chain reaction. These results, together with differences in the expression levels of plant defence genes in the roots of both interactions, support a key role for SA in Trichoderma early root colonization stages. We observed that, without the support of SA, plants were unable to prevent the arrival of the fungus in the vascular system and its spread into aerial parts, leading to later collapse.
Chaverri, Priscila; Branco-Rocha, Fabiano; Jaklitsch, Walter; Gazis, Romina; Degenkolb, Thomas; Samuels, Gary J
Trichoderma harzianum is known as a cosmopolitan, ubiquitous species associated with a wide variety of substrates. It is possibly the most commonly used name in agricultural applications involving Trichoderma, including biological control of plant diseases. While various studies have suggested that T. harzianum is a species complex, only a few cryptic species are named. In the present study the taxonomy of the T. harzianum species complex is revised to include at least 14 species. Previously named species included in the complex are T. guizhouense, T. harzianum, and T. inhamatum. Two new combinations are proposed, T. lentiforme and T. lixii. Nine species are described as new, T. afarasin, T. afroharzianum, T. atrobrunneum, T. camerunense, T. endophyticum, T. neotropicale, T. pyramidale, T. rifaii and T. simmonsii. We isolated Trichoderma cultures from four commercial biocontrol products reported to contain T. harzianum. None of the biocontrol strains were identified as T. harzianum s. str. In addition, the widely applied culture 'T. harzianum T22' was determined to be T. afroharzianum. Some species in the T. harzianum complex appear to be exclusively endophytic, while others were only isolated from soil. Sexual states are rare. Descriptions and illustrations are provided. A secondary barcode, nuc translation elongation factor 1-α (TEF1) is needed to identify species in this complex.
Kauppinen, Miia; Saikkonen, Kari; Helander, Marjo; Pirttilä, Anna Maria; Wäli, Piippa R
There is an urgent need to create new solutions for sustainable agricultural practices that circumvent the heavy use of fertilizers and pesticides and increase the resilience of agricultural systems to environmental change. Beneficial microbial symbionts of plants are expected to play an important role in integrated pest management schemes over the coming decades. Epichloë endophytes, symbiotic fungi of many grass species, can protect plants against several stressors, and could therefore help to increase the productivity of forage grasses and the hardiness of turf grasses while reducing the use of synthetic pesticides. Indeed, Epichloë endophytes have successfully been developed and commercialized for agricultural use in the USA, Australia and New Zealand. Many of the host grass species originate from Europe, which is a biodiversity hotspot for both grasses and endophytes. However, intentional use of endophyte-enhanced grasses in Europe is virtually non-existent. We suggest that the diversity of European Epichloë endophytes and their host grasses should be exploited for the development of sustainable agricultural, horticultural and landscaping practices, and potentially for bioremediation and bioenergy purposes, and for environmental improvement.
@@ In order to identify Trichoderma species isolated from Iran, Trichoderma selective media and malt extract agar (MEA) were used to isolate Trichoderma species from the soil samples. All the cultures were purified on 2% water agar by hyphal tip method prior to morphological examination.Morphological observations were carried out on the cultures grown on 2% MEA and oat meal agar at 20℃ under ambient laboratory conditions. Macroscopic features of colony and microscopic features of conidiophore, phialid and conidium including position of phialids on conidiophore and shape and size of phialids and conidia were studied and recorded 3-5 days after inoculation. Out of 36 tested isolates, using morphological features and molecular data obtained from ITS1, ITS2 and 5.8S regions fourteen species were identified as follow: T. atroviride, T. ghanense, T. spirale, T. erinaceum, T. citrinoviride, T. saturnisporum,T. longibrachiatum , T. hamatum , T. harzianum, T. inhamatum , T. tomentosum , T.virens, T. asperellum, T. koningii. Among the species T. harzianum and T. virens isolates were the most frequent species. In addition of the mentioned species two Tichoderma sp. were collected from walnut rhizospher that they are not fit to any described species so far. Although one of them are T. brevicumpactum introduced informally.
Full Text Available Plant inoculation with endophytic bacteria that normally live inside the plant without harming the host is a highly promising approach for biological disease control. The mechanism of resistance induction by beneficial bacteria is poorly understood, because pathways are only partly known and systemic responses are typically not seen. The innate endophytic community structures change in response to external factors such as inoculation, and bacterial endophytes can exhibit direct or indirect antagonism towards pathogens. Earlier we showed that resistance induction by an endophytic Methylobacterium sp. in potato towards Pectobacterium atrosepticum was dependent on the density of the inoculum, whereas the bacterium itself had no antagonistic activity. To elucidate the role of innate endophyte communities in plant responses, we studied community changes in both in vitro and greenhouse experiments using various combinations of plants, endophyte inoculants, and pathogens. Induction of resistance was studied in several potato (Solanum tuberosum L. cultivars by Methylobacterium sp. IMBG290 against the pathogens P. atrosepticum, Phytophthora infestans and Pseudomonas syringae pv. tomato DC3000, and in pine (Pinus sylvestris L. by M. extorquens DSM13060 against Gremmeniella abietina. The capacities of the inoculated endophytic Methylobacterium spp. strains to induce resistance were dependent on the plant cultivar, pathogen, and on the density of Methylobacterium spp. inoculum. Composition of the endophyte community changed in response to inoculation in shoot tissues and correlated with resistance or susceptibility to the disease. Our results demonstrate that endophytic Methylobacterium spp. strains have varying effects on plant disease resistance, which can be modulated through the endophyte community of the host.
B. Shankar Naik; M. Krishnappa; Y. L. Krishnamurthy
A total of 3611 fungal isolates were recovered from 4200 leaf segments incubated from 7 medicinal herbs during monsoon, winter and summer seasons. These fungal isolates belonged to teleomorphic Asco-mycota (23.5%), anamorphic Ascomycota producing conidiomata (17.4%), anamorphic Ascomycota without conidiomata (46.9%), Zygo-mycota (1.42%) and sterile forms (10.6%). Chaetomium globosum, As-pergillus niger, Aureobasidium pullulans, Curvularia lunata, Fusarium spp., Penicillium spp., Pestalotiopsis spp., Trichoderma viridae, Cladosporium cladosporioides, were frequently isolated from more than one host plant. The number of endophytic isolates was higher in winter than in monsoon and summer seasons.
Ciliento R; Mach R L; Lorito M; Woo S L; Di Benedetto P; Ruocco M; Scala F; Soriente I; Ferraioli S; Brunner K; Zeilinger S
@@ The beneficial applications of Trichoderma spp. in agriculture include not only the control of plant pathogens, but also the improvement of plant growth, micronutrient availability, and plant tolerance to abiotic stress. In addition, it has been suggested that these fungi are able to increase plant disease resistance by activating induced systemic resistance (ISR) . The mode of action of these beneficial fungi in the Trichoderma -plant-pathogen interaction are many, complex and not completely understood. Numerous lytic enzymes have been characterized, the encoding genes (ech42 gluc78,nag1 from T. atroviride strain P1) cloned, and their role in biocontrol demonstrated. The corresponding biocontrol-related inducible promoters have been used in a reporter system based on the Aspergillus niger glucose oxidase gene (goxA) to monitor biocontrol activity. Glucose oxidase catalyzes the oxygen-dependent oxidation of D-glucose to D-glucono-1, 5-lactone and hydrogen peroxide; this latter compound is known to have an antifungal effect and activate the plant defence cascade, thus increasing resistance to pathogen attack. T. atroviride P1 transformants with various promoters gox were tested as seed coating treatments on bean seeds planted in soil infested with a soilborne fungal pathogen. Successively, the emergent leaves were inoculated with a foliar pathogen to determine the effect of the GOX transformants on biocontrol and resistance to pathogen attack.Inoculations with the P1-GOX transformants not only reduced disease symptoms caused by a soil pathogen, but also the lesions of various foliar pathogens applied far from the Trichoderma colonization, thus activating ISR. A similar approach is being use to genetically improve T.harzianum T22, a rhizosphere competent and commercially marketed strain not transformed yet, by using four different gox gene constructs under the control of constitutive and inducible promoters.Plasmids have been introduced in Trichoderma by
White, James F; Torres, Mónica S
In this review, we discuss the biology and beneficial effects of plant endophytes on host plants. The current explanation of endophyte protection (defensive mutualism) of host plants is based on the secondary metabolites (alkaloids) with antiherbivore properties produced by the symbiotic association between host plant and endophytes. We propose an alternative explanation of the mechanism of host protection through enhanced stress tolerance to oxidative stress. Several studies have demonstrated the production of different compounds (phenolics) with antioxidant capacity in endophyte-infected plants. Endophytes may also produce mannitol, other carbohydrates and small molecules (proline) with antioxidant capacity. We suggest that enhanced antioxidant production by symbiotic plants may be the result of the production of reactive oxygen species (ROS) by endophytes. In turn, symbiotic plants are protected from oxidative stress produced by plant diseases, droughts, heavy metals and other oxidative stressors by the production of antioxidants. We also discuss the lichen symbiosis and evaluate whether management of ROS also plays a role in this defensive mutualism. Future experiments are needed to evaluate the hypothesis that antioxidants are responsible for enhanced stress tolerance in endophyte-infected plants.
Mirzahossini, Zahra; Shabani, Leila; Sabzalian, Mohammad R; Sharifi-Tehrani, Majid
Epichloe endophytes are symbiotic fungi which unlike mycorrhiza grow within aerial parts of host plants. The fungi may increase host tolerance to both biotic and abiotic stresses. In this study, the effect of endophyte infection on growth and tolerance, carbohydrate contents and ABC (ABC transporter) and MET (metallothionein) expression in the leaves of tall fescue (Festuca arundinacea) plants cultivated in Ni polluted soil were evaluated. The endophyte infected (E+) and non-infected (E-) fescue plants were cultivated in soil under different Ni concentrations (30, 90 and 180mgkg(-1)). Growth parameters including root, shoot, total biomass, tiller number and total chlorophyll content of plants and H2O2 content of shoots were measured at the end of experiment. Ni translocation to the shoots, carbohydrate contents in roots and expression of ABC and MET of the leaves were also measured after 10 weeks of growth. Results demonstrated the beneficial effect of endophyte association on growth and Ni tolerance of tall fescue under Ni stress through an avoidance mechanism (reduction of Ni accumulation and translocation to the shoots). Endophyte infected plants showed less ABC and MET expression compared to the endophyte free plants. In endophyte free plants, H2O2 production had a significant positive correlation with genes expression, indicating that an increase in H2O2 might be involved in the up-regulation of ABC and MET under Ni stress.
Young, Carolyn A.; Tapper, Brian A.; May, Kimberley; Moon, Christina D.; Schardl, Christopher L.; Scott, Barry
Bioprotective alkaloids produced by Epichloë and closely related asexual Neotyphodium fungal endophytes protect their grass hosts from insect and mammalian herbivory. One class of these compounds, known for antimammalian toxicity, is the indole-diterpenes. The LTM locus of Neotyphodium lolii (Lp19) and Epichloë festuce (Fl1), required for the biosynthesis of the indole-diterpene lolitrem, consists of 10 ltm genes. We have used PCR and Southern analysis to screen a broad taxonomic range of 44 endophyte isolates to determine why indole-diterpenes are present in so few endophyte-grass associations in comparison to that of the other bioprotective alkaloids, which are more widespread among the endophtyes. All 10 ltm genes were present in only three epichloë endophytes. A predominance of the asexual Neotyphodium spp. examined contained 8 of the 10 ltm genes, with only one N. lolii containing the entire LTM locus and the ability to produce lolitrems. Liquid chromatography-tandem mass spectrometry profiles of indole-diterpenes from a subset of endophyte-infected perennial ryegrass showed that endophytes that contained functional genes present in ltm clusters 1 and 2 were capable of producing simple indole-diterpenes such as paspaline, 13-desoxypaxilline, and terpendoles, compounds predicted to be precursors of lolitrem B. Analysis of toxin biosynthesis genes by PCR now enables a diagnostic method to screen endophytes for both beneficial and detrimental alkaloids and can be used as a resource for screening isolates required for forage improvement. PMID:19181837
Walaa Kamel Mousa
Full Text Available Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes that contribute to the antifungal activity. Here we report the first isolation of endophyte(s from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp. was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation.
Bezerra, Jadson D P; Nascimento, Carlos C F; Barbosa, Renan do N; da Silva, Dianny C V; Svedese, Virgínia M; Silva-Nogueira, Eliane B; Gomes, Bruno S; Paiva, Laura M; Souza-Motta, Cristina M
Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen's index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus , Gibberella baccata , Penicillium commune , and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes . Thirteen species showed proteolytic activity, particularly Phoma putaminum . Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri . All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum . It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.
Jadson D.P. Bezerra
Full Text Available Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds, comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%, Aspergillus ochraceus (7.37%, Gibberella fujikuroi (10.53%, Myrothecium verrucaria (10.53% and Trichoderma piluliferum(7.37%. Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus, Gibberella baccata, Penicillium commune, and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes. Thirteen species showed proteolytic activity, particularly Phoma putaminum. Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri. All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum. It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.
Full Text Available Douglas-fir (Pseudotsuga menziesii seedlings are periodically challenged by biotic and abiotic stresses. The ability of endophytes to colonize the interior of plants could confer benefits to host plants that may play an important role in plant adaptation to environmental changes. In this greenhouse study, nursery-grown Douglas-fir seedlings were inoculated with diazotrophic endophytes previously isolated from poplar and willow trees and grown for fifteen months in nutrient-poor conditions. Inoculated seedlings had significant increases in biomass (48%, root length (13% and shoot height (16% compared to the control seedlings. Characterization of these endophytes for symbiotic traits in addition to nitrogen fixation revealed that they can also solubilize phosphate and produce siderophores. Colonization was observed through fluorescent microscopy in seedlings inoculated with gfp- and mkate-tagged strains. Inoculation with beneficial endophytes could prove to be valuable for increasing the production of planting stocks in forest nurseries.
The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.
Pieterse, Corné M J; Zamioudis, Christos; Berendsen, Roeland L; Weller, David M; Van Wees, Saskia C M; Bakker, Peter A H M
Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth-promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of pathogens and insect herbivores. A wide variety of root-associated mutualists, including Pseudomonas, Bacillus, Trichoderma, and mycorrhiza species sensitize the plant immune system for enhanced defense without directly activating costly defenses. This review focuses on molecular processes at the interface between plant roots and ISR-eliciting mutualists, and on the progress in our understanding of ISR signaling and systemic defense priming. The central role of the root-specific transcription factor MYB72 in the onset of ISR and the role of phytohormones and defense regulatory proteins in the expression of ISR in aboveground plant parts are highlighted. Finally, the ecological function of ISR-inducing microbes in the root microbiome is discussed.
Druzhinina, Irina S.; Seiboth, Verena Seidl; Estrella, Alfredo Herrera; Horwitz, Benjamin A.; Kenerley, Charles M.; Monte, Enrique; Mukherjee, Prasun K.; Zeilinger, Susanne; Grigoriev, Igor V.; Kubicek, Christian P.
Trichoderma is a genus of common filamentous fungi that display a remarkable range of lifestyles and interactions with other fungi, animals and plants. Because of their ability to antagonize plant-pathogenic fungi and to stimulate plant growth and defence responses, some Trichoderma strains are used for biological control of plant diseases. In this Review, we discuss recent advances in molecular ecology and genomics which indicate that the interactions of Trichoderma spp. with animals and plants may have evolved as a result of saprotrophy on fungal biomass (mycotrophy) and various forms of parasitism on other fungi (mycoparasitism), combined with broad environmental opportunism.
McKinnon, Aimee C.; Saari, Susanna; Moran-Diez, Maria E.;
In the last decade there has been increased focus on the potential of endophytic Beauveria bassiana for the biocontrol of insect herbivores. Generally, detection of endophytes is acknowledged to be problematic and recovery method-dependent. Herein, we critically analyse the methodology reported...
Rosa, Luiz H; Tabanca, Nurhayat; Techen, Natascha; Pan, Zhiqiang; Wedge, David E; Moraes, Rita M
The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely related to species of the genera Bionectria , Cladosporium , Colletotrichum , Fusarium , Gibberella , Hypocrea , Lecythophora , Nigrospora , Plectosphaerella , and Trichoderma . The endophytic assemblages of S. sonchifolius presented a greater diversity than the group isolated from S. uvedalius and demonstrated the presence of dominant generalist fungi. Extracts of all fungi were screened against the fungal plant pathogens. Ten extracts (41.6%) displayed antifungal activities; some of them had a broad antifungal activity. The phylotypes Lecythophora sp. 1, Lecythophora sp. 2, and Fusarium oxysporum were isolated from in vitro autotrophic cultures and displayed antifungal activity. The presence of bioactive endophytic fungi within S. sonchifolius and S. uvedalius suggests an ecological advantage against pathogenic attacks. This study revealed reduced numbers of endophytes in association with both Smallanthus species in controlled cultivation conditions compared with the endophytic communities of hosts collected in the wild environments. Even as reduced endophytic communities, these fungi continue to provide chemical protection for the host.
Card, Stuart D; Faville, Marty J; Simpson, Wayne R; Johnson, Richard D; Voisey, Christine R; de Bonth, Anouck C M; Hume, David E
Grasses of the tribe Triticeae were screened to determine the presence of mutualistic epichloae fungal endophytes. Over 1500 accessions, from more than 250 species, encompassing 22 genera within the Triticeae were screened using immunodetection and direct staining/microscopy techniques. Only two genera, Elymus and Hordeum, were identified as harbouring epichloae endophytes with accessions native to a range of countries including Canada, China, Iran, Kazakhstan, Kyrgyzstan, Mongolia, Russia and the USA. Genetic analysis based on simple sequence repeat data revealed that the majority of endophytes cluster according to geographical regions rather than to host species; many strains isolated from Hordeum grouped with those derived from Elymus, and amongst the Elymus-derived strains, there was no clear correspondence between clustering topology and host species. This is the first detailed survey demonstrating the genetic diversity of epichloae endophytes within the Triticeae and highlights the importance of germplasm centres for not only preserving the genetic diversity of plant species but also the beneficial microorganisms they may contain.
Kumari, Indu; Chaudhary, Nitika; Sandhu, Padmani; Ahmed, Mushtaq; Akhter, Yusuf
Trichoderma spp. are well-known bioagents for the plant growth promotion and pathogen suppression. The beneficial activities of the fungus Trichoderma spp. are attributed to their ability to produce and secrete certain secondary metabolites such as trichodermin that belongs to trichothecene family of molecules. The initial steps of trichodermin biosynthetic pathway in Trichoderma are similar to the trichothecenes from Fusarium sporotrichioides. Trichodiene synthase (TS) encoded by tri5 gene in Trichoderma catalyses the conversion of farnesyl pyrophosphate to trichodiene as reported earlier. In this study, we have carried out a comprehensive comparative sequence and structural analysis of the TS, which revealed the conserved residues involved in catalytic activity of the protein. In silico, modelled tertiary structure of TS protein showed stable structural behaviour during simulations. Two single-substitution mutants, i.e. D109E, D248Y and one double-substitution mutant (D109E and D248Y) of TS with potentially higher activities are screened out. The mutant proteins showed more stability than the wild type, an increased number of electrostatic interactions and better binding energies with the ligand, which further elucidates the amino acid residues involved in the reaction mechanism. These results will lead to devise strategies for higher TS activity to ultimately enhance the trichodermin production by Trichoderma spp. for its better exploitation in the sustainable agricultural practices.
Qin, Jun-hua; Lu, Yu; Li, Xia; Zhou, Yong; Ren, An-zhi; Gao, Yu-bao
We used Achnatherum sibiricum, a native grass as test material and application of methyl jasmonate (MJ) to simulate herbivory, and compared the growth and physiological characters of endophyte-infected (EI) and endophyte-free (EF) plants. The results showed that MJ treatment significantly decreased the shoot growth, but significantly increased the concentrations of defensive substances such as total phenolic and lignin, and decreased the size of aphid population. Endophyte infection significantly increased the tiller number, total phenolic and lignin contents in the shoot. As for shoot biomass and total phenolic in the root, they were affected by MJ treatment. Without MJ treatment, no significant differences were found in shoot biomass or root phenolic content whether the plants were infected by endophyte or not. With MJ treatment, the shoot biomass was significantly lower and the shoot phenolic content was significantly higher in EI plants than in EF plants. Endophyte infection significantly increased resistance of the host plant to aphids, and the beneficial effect was enhanced by MJ treatments, after three applications with MJ, there were no aphids on EI plants. Overall, endophyte infection could alter the allocation pattern of the host plant between growth and defense, and MJ treatments further strengthened the defensive ability of the host plant at the cost of growth.
Gabriela B. Valencia
Full Text Available Problem statement: Presence of Trichoderma spp. in agricultural soils decrease incidence of diseases by phytopathogen fungi. Sanity diagnostic require to know if exist beneficial microorganism and what agricultural practices help to their propagation. Approach: Samples (30 were taken from soils and sick plants of ten sites in four localities of Valley of Poanas. Phytophthora capsici Leo, Rhizoctonia solani Kuhn and Trichoderma sp were isolated in agar V8 and were identified by microscopy. Results: In the 30 samples analyzed the presence of Phytophthora capsici Leo and Rhizoctonia solani Kuhn was determined. Two isolations of Trichoderma sp were obtained from soil, they had antagonist activity against to P. capsici and R. solani on agar-V8 medium and showed chitinase activity. Sugar production in chitinase (10 mg.mL-1 by crude extract of Trichoderma growth in basal medium more chitin was determined. The average of sugar production from strains were 0.1175 and 0.1125 mg.mL-1 and standard deviations were 0.0567 and 0.0567 in four repetition. Interviews were applied to fifty farmers about cultivars and cultivation practices. At least seven types of chili were cultivated in the region of the Valley of Poanas, inorganic fertilization, irrigation systems by channel, gates and pumps were used. One hundred percent of farmers reported diseases of Damping off and Phytophthora root. Biocides were not used to control these diseases. Conclusion: The natural presence of Trichoderma spp was detected in Valley of Poanas, but some practices as inorganic fertilization and irrigation system can be contributing to propagation of phytopathogen fungi.
Full Text Available Plant pathogens and endophytes co-exist and often interact with the host plant and within its microbial community. The outcome of these interactions may lead to healthy plants through beneficial interactions, or to disease through the inducible production of molecules known as virulence factors. Unravelling the role of virulence in endophytes may crucially improve our understanding of host-associated microbial communities and their correlation with host health.Virulence is the outcome of a complex network of interactions, and drawing the line between pathogens and endophytes has proven to be conflictive, as strain-level differences in niche overlapping, ecological interactions, state of the host’s immune system and environmental factors are seldom taken into account. Defining genomic differences between endophytes and plant pathogens is decisive for understanding the boundaries between these two groups. Here we describe the major differences at the genomic level between seven grapevine endophytic test bacteria, and twelve reference strains. We describe the virulence factors detected in the genomes of the test group, as compared to endophytic and non-endophytic references, to better understand the distribution of these traits in endophytic genomes. To do this, we adopted a comparative whole-genome approach, encompassing BLAST-based searches through the GUI-based tools Mauve and BRIG as well as calculating the core and accessory genomes of three genera of enterobacteria. We outline divergences in metabolic pathways of these endophytes and reference strains, with the aid of the online platform RAST. We present a summary of the major differences that help in the drawing of the boundaries between harmless and harmful bacteria, in the spirit of contributing to a microbiological definition of endophyte.
Hanada, Rogério Eiji; Pomella, Alan William V; Costa, Heron Salazar; Bezerra, José Luiz; Loguercio, Leandro L; Pereira, José O
The endophytic niches of plants are a rich source of microbes that can directly and indirectly promote plant protection, growth and development. The diversity of culturable endophytic fungi from stems and branches of Theobroma cacao (cacao) and Theobroma grandiflorum (cupuaçu) trees growing in the Amazon region of Brazil was assessed. The collection of fungal endophytic isolates obtained was applied in field experiments to evaluate their potential as biocontrol agents against Phytophthora palmivora, the causal agent of the black-pod rot disease of cacao, one of the most important pathogens in cocoa-producing regions worldwide. The isolated endophytic fungi from 60 traditional, farmer-planted, healthy cacao and 10 cupuaçu plants were cultured in PDA under conditions inducing sporulation. Isolates were classified based upon the morphological characteristics of their cultures and reproductive structures. Spore suspensions from a total of 103 isolates that could be classified at least up to genus level were tested against P. palmivora in pods attached to cacao trees in the field. Results indicated that ∼70% of isolates showed biocontrol effects to a certain extent, suggesting that culturable endophytic fungal biodiversity in this system is of a mostly mutualistic type of interaction with the host. Eight isolates from genera Trichoderma (reference isolate), Pestalotiopsis, Curvularia, Tolypocladium and Fusarium showed the highest level of activity against the pathogen, and were further characterized. All demonstrated their endophytic nature by colonizing axenic cacao plantlets, and confirmed their biocontrol activity on attached pods trials by showing significant decrease in disease severity in relation to the positive control. None, however, showed detectable growth-promotion effects. Aspects related to endophytic biodiversity and host-pathogen-endophyte interactions in the environment of this study were discussed on the context of developing sustainable strategies
Zhu, Xuezhu; Ni, Xue; Waigi, Michael Gatheru; Liu, Juan; Sun, Kai; Gao, Yanzheng
Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P₁ (Stenotrophomonas sp.) and P₃ (Pseudomonas sp.), which degraded more than 90% of phenanthrene (PHE) within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP), PHE, fluorene (FLR), pyrene (PYR), and benzo(a)pyrene (B(a)P) as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P₁ degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(a)P, and strain P₃ degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(a)P. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days). Compared with strain P₁, strain P₃ has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.
Full Text Available Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P1 (Stenotrophomonas sp. and P3 (Pseudomonas sp., which degraded more than 90% of phenanthrene (PHE within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP, PHE, fluorene (FLR, pyrene (PYR, and benzo(apyrene (B(aP as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P1 degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(aP, and strain P3 degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(aP. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days. Compared with strain P1, strain P3 has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.
Pablo R Hardoim
Full Text Available Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed.
Hoyos-Carvajal, Lilliana; Orduz, Sergio; Bissett, John
The genus Trichoderma has been studied for production of enzymes and other metabolites, as well as for exploitation as effective biological control agents. The biodiversity of Trichoderma has seen relatively limited study over much of the neotropical region. In the current study we assess the biodiversity of 183 isolates from Mexico, Guatemala, Panama, Ecuador, Peru, Brazil and Colombia, using morphological, metabolic and genetic approaches. A comparatively high diversity of species was found, comprising 29 taxa: Trichoderma asperellum (60 isolates), Trichoderma atroviride (3), Trichoderma brevicompactum (5), Trichoderma crassum (3), Trichoderma erinaceum (3), Trichoderma gamsii (2), Trichoderma hamatum (2), Trichoderma harzianum (49), Trichoderma koningiopsis (6), Trichoderma longibrachiatum (3), Trichoderma ovalisporum (1), Trichoderma pubescens (2), Trichoderma rossicum (4), Trichoderma spirale (1), Trichoderma tomentosum (3), Trichoderma virens (8), Trichoderma viridescens (7) and Hypocrea jecorina (3) (anamorph: Trichoderma reesei), along with 11 currently undescribed species. T. asperellum was the prevalent species and was represented by two distinct genotypes with different metabolic profiles and habitat preferences. The second predominant species, T. harzianum, was represented by three distinct genotypes. The addition of 11 currently undescribed species is evidence of the considerable unresolved biodiversity of Trichoderma in neotropical regions. Sequencing of the internal transcribed spacer regions (ITS) of the ribosomal repeat could not differentiate some species, and taken alone gave several misidentifications in part due to the presence of nonorthologous copies of the ITS in some isolates.
Segarra, G.; Ent, S. van der; Trillas, I.; Pieterse, C.M.J.
Colonisation of plant roots by selected beneficial Trichoderma fungi or Pseudomonas bacteria can result in the activation of a systemic defence response that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, induced systemic resistance (ISR) triggered by the rhizobacterial
Suryanarayanan, Trichur S; Wittlinger, Sally K; Faeth, Stanley H
21 cactus species occurring in various localities within Arizona were screened for the presence of fungal endophytes. 900 endophyte isolates belonging to 22 fungal species were isolated. Cylindropuntia fulgida had the maximum endophyte species diversity, while C. ramosissima harboured the maximum number of endophyte isolates. Alternaria sp., Aureobasidium pullulans, and Phoma spp. were isolated from several cactus species. The diversity of the endophyte assemblages was low and no host specificity among endophytes was observed. However, the frequencies of colonization of the few endophyte species recovered were high and comparable to those reported for tropical plant hosts. Species of Colletotrichum, Phomopsis, and Phyllosticta, which are commonly isolated as endophytes from plants of more mesic habitats, were absent from these cacti.
LIANG Chen; LI Bao-du; LU Guo-zhong
@@ Gliocladium and Trichoderma are common fungi in agricultural soil. Several species of them were isolated and identified, great diversity was displayed in different agricultural soils of different crops,agricultural climate zones, different seasons, depths, different treated soybean cyst nematode soil,healthy and diseased crop soil. Among five crops soil samples, wheat and corn soil were found to possess the largest number of Gliocladium and Trichoderma separately. Gliocladium and Trichoderma of three major crops showed consistent changing patterns with seasonal variation. Corn soil displayed distinct vertical distribution of Trichoderna. There is a different distribution of the two fungi in diseased and healthy plant soil. Among the various isolated methods, diluted plate method is the best for isolating Gliocladium, and Trichoderma could be found in plant residue method and be tolerant to steam for two minutes. In the soybean cyst nematode soil mycobiota, the frequency of Gliocladium is higher than that of the others fungi, and Trichoderma may have the role of bioremediation in herbicide treated soil. Similarly, Gliocladium occurred frequently in different climate zones.
Full Text Available This work evaluated the char morphology of beneficiated and original coal (without beneficiation from four Colombian coalmines: Cerrejón (La Guajira, La Jagua (Cesar, Guachinte (Valle del Cauca and Nechí (Antioquia. Column flotation was used to obtain beneficiated coal, whereas a drop tube reactor at 1,000°C, 104 °C/s heating rate and 100 ms residence time was used to obtain char. The chars were analysed by image analysis which determined their shape, size, porosity and wall thickness. It was found that char morphology depended on coal rank and maceral composition. Morphological characteristics like high porosity, thinner walls and network-like morphology which are beneficial in improving combustion were present in vitrinite- and liptinite-rich lowest-ranking coals. Beneficiated coals showed that their chars had better performance regarding their morphological characteristics than their original coal chars.
Huang, Qian; An, Hongmei; Song, Hongchuan; Mao, Hongqiang; Shen, Weiyun; Dong, Jinyan
This study investigated the diversity and host component-transforming activity of endophytic fungi in medicinal plant Kadsura angustifolia. A total of 426 isolates obtained were grouped into 42 taxa belonging to Fungi Imperfecti (65.96%), Ascomycota (27.00%), Zygomycota (1.64%), Basidiomycota (0.47%) and Mycelia Sterilia (4.93%). The abundance, richness, and species composition of endophytic assemblages were significantly dependent on the tissue and the sampling site. Many phytopathogenic species associated with healthy K. angustifolia were found prevalent. Among them, Verticillium dahliae was dominant with 16.43% abundance. From 134 morphospecies selected, 39 showed remarkable biocatalytic activity and were further identified as species belonging to the genera Colletotrichum, Eupenicillium, Fusarium, Hypoxylon, Penicillium, Phomopsis, Trametes, Trichoderma, Umbelopsis, Verticillium and Xylaria on the basis of the sequence analysis of the internal transcribed spacer (ITS1-5.8S-ITS2). The results obtained in this work show that K. angustifolia is an interesting reservoir of pathogenic fungal species, and could be a community model for further ecological and evolutionary studies. Additionally, the converting potency screening of some endophytic fungi from this specific medicinal plant may provide an interesting niche on the search for novel biocatalysts.
Full Text Available Endophytic fungi from three commonly found seagrasses in southern Thailand were explored for their ability to produce antimicrobial metabolites. One hundred and sixty endophytic fungi derived from Cymodoceaserrulata (Family Cymodoceaceae, Halophilaovalis and Thalassiahemprichii (Family Hydrocharitaceae were screened for production of antimicrobial compounds by a colorimetric broth microdilution test against ten human pathogenic microorganisms including Staphylococcus aureus ATCC 25923, a clinical isolate of methicillin-resistant S. aureus, Escherichia coli ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028 and NCPF 3153, Cryptococcus neoformans ATCC 90112 and ATCC 90113 and clinical isolates of Microsporumgypseum and Penicilliummarneffei. Sixty-nine percent of the isolates exhibited antimicrobial activity against at least one test strain. Antifungal activity was more pronounced than antibacterial activity. Among the active fungi, seven isolates including Hypocreales sp. PSU-ES26 from C. serrulata, Trichoderma spp. PSU-ES8 and PSU-ES38 from H. ovalis, and Penicillium sp. PSU-ES43, Fusarium sp. PSU-ES73, Stephanonectria sp. PSU-ES172 and an unidentified endophyte PSU-ES190 from T. hemprichii exhibited strong antimicrobial activity against human pathogens with minimum inhibitory concentrations (MIC of less than 10 µg/ml. The inhibitory extracts at concentrations of 4 times their MIC destroyed the targeted cells as observed by scanning electron microscopy. These results showed the antimicrobial potential of extracts from endophytic fungi from seagrasses.
@@ Trichoderna spp. have been known for their strong abilities to produce extracellular enzymes,especially cellulases and glucanases by T. reesei, and also for their abilities to control plant pathogens.Most notably, a number of lines of evidence indicate that the agriculturally relevant strains are synergistic plant symbionts. As plant symbionts they possess the following characteristics: (a) they infect plant roots but cause the plant to restrict their growth to outer layers of the plant cortex (an exception is the recent discoveries of plant endophytic strains of Trichoderma and Gliocladium), (b)they produce bioactive plant molecules in the zone of interaction that (c) induce localized systemic resistance to plant diseases and (d) systemic plant resistance to diseases that in some respects is similar to that induced by rhizobacteria, (e) they induce changes in plant proteomes, (f) increase plant growth and yield at least in part by enhancing root growth, and (g) they increase plant nutrient uptake. The increase in plant growth and yields is strongly interactive with plant genotype, at least in maize. There also are very significant increases in the knowledge of events that occur in mycoparasitism that in many respects have features in common with their interactions with plants.They are highly resistant to toxicants and have recently been shown to degrade cyanide and take up,and then degrade, metallocyanides. These discoveries allow new uses for the organisms in managed plant systems, including agriculture. For example, the induced systemic resistance system allows control of fungi, bacteria, Oomycetes and even one virus at sites temporally and spatially distant from the site of application. The abilities of the fungi to resist/degrade toxicants and increase plant growth indicate they will highly useful components in plant-microbe or microbe-only strategies for remediation of soil and water pollution. Finally, there are new uses of their enzyme systems for
Fungal endophytes can influence host health, and more broadly, can instigate trophic cascades with effects scaling to the ecosystem level. Despite this, biotic mechanisms of endophyte community assembly are largely unknown. We used maize to investigate three potential habitat filters in endophyte co...
LIU Kai-qi; XIANG Mei-mei; LIU Ren; ZENG Yong-san; ZHOU Hong-zi; YU Jin-feng; JIANG Xin-yin; ZHANG Yue-li
@@ The screening of isolates and the assay of biocontrol mechanisms of Trichoderma were studied systematically in laboratory and greenhouse in vivo. The proteins tolerant to benzimidazole in Trichoderma strains were purified, and their physical and chemical properties were detected. Compared their biological activities in vitro and vivo in greenhouse, nine biocontrol strains (including Ty- 10-2, LTR-2, Tj-5-1, Tj-5-4, Ty- 11-1, Tj-11-3, Ty- 11-3, Tj-3-3-2, Tj-3-3-4) were screened. These biocontrol strains had faster rates of growth and higher inhibition to gray mould (Bortrytis cinerea),and the inhibition was stable. The effects of controlling gray mould in greenhouse with the screened Trichoderma strains were 70 % and 50 % in vivo.
Bansal, Ravindra; Mukherjee, Prasun Kumar
The widely used biotechnologically important fungi belonging to the genus Trichoderma are rich sources of secondary metabolites. Even though the genomes of several Trichoderma spp. have been published, and data are available on the genes involved in biosynthesis of non-ribosomal peptide synthetases and polyketide synthases, no genome-wide data are available for the terpenoid biosynthesis machinery in these organisms. In the present study, we have identified the genes involved in terpene biosynthesis in the genomes of three Trichoderma spp., viz., T. virens, T. atroviride and T. reesei. While the genes involved in the condensation steps are highly conserved across the three species, these fungi differed in the number and organization of terpene cyclases. T. virens genome harbours eleven terpene cyclases, while T. atroviride harbours seven, and T. reeseisix in their genomes; seven, three and two being part of putative secondary metabolism related gene clusters.
Kun CHENG; Yanqiong YANG; Changling ZHAO; Li WANG; Shuying CHEN; Yuhan SHEN; Jing CHAI; Key words Paris polyphylla var. yunnanensis; Endophytic fungus; P. polyphylla var. yunnanensis seed; Embryo development; Embryo
Abstract [Objective] This study aimed to isolate the endophytic fungi of Paris poly- phylla var. yunnanensis and investigate their effects on the embryo development of P. polyphylla var. yunnanensis seeds. [Method] The endophytic fungi of P. poly- phylla were isolated and identified morphologically, and their effects on the embryo development of P. polyphylla var. yunnanensis seeds were studied by using paraffin sectioning and microphotography. [Result] Nine endophytic fungi, Le. P. polyphylla var. yunnanensis endophytic fungi PPYEF-1, PPYEF-2, PPYEF-3, PPYEF-4, PPYEF- 5, PPYEF-6, PPYEF-7, PPYEF-8 and PPYEF-9 belonging to seven genera in five families, three orders were isolated from the rhizomes. Except PPYEF-4 （Cladospori- um sp.）, other fungi could promote the embryo development of the P. polyphylla var. yunnanensis seeds, mostly reaching the extremely significant or significant level. PPYEF-9 （Trichoderma sp.） resulted in the highest embryo length and embryo-e- merging ratio. [Conclusion] This paper could provide a reference for the applica- tion of the endophytic fungi of P. polyphylla var. yunnanensis in the dormancy- breaking of P. polyphylla var. yunnanensis seeds.
Berdahl, Andrew; De Bacco, Caterina; Dumas, Marion; Ferdinand, Vanessa; Grochow, Joshua A; Hébert-Dufresne, Laurent; Kallus, Yoav; Kempes, Christopher P; Kolchinsky, Artemy; Larremore, Daniel B; Libby, Eric; Power, Eleanor A; Stern, Caitlin A; Tracey, Brendan
Pathogens can spread epidemically through populations. Beneficial contagions, such as viruses that enhance host survival or technological innovations that improve quality of life, also have the potential to spread epidemically. How do the dynamics of beneficial biological and social epidemics differ from those of detrimental epidemics? We investigate this question using three theoretical approaches as well as an empirical analysis of concept propagation. First, in evolutionary models, we show that a beneficial horizontally-transmissible element, such as viral DNA, spreads super-exponentially through a population, substantially more quickly than a beneficial mutation. Second, in an epidemiological social network approach, we show that infections that cause increased connectivity lead to faster-than-exponential fixation in the population. Third, in a sociological model with strategic rewiring, we find that preferences for increased global infection accelerate spread and produce super-exponential fixation rates,...
Saroj, Dina B; Dengeti, Shrinivas N; Aher, Supriya; Gupta, Anil K
Trichoderma species are widely used as production hosts for industrial enzymes. Identification of Trichoderma species requires a complex molecular biology based identification involving amplification and sequencing of multiple genes. Industrial laboratories are required to run identification tests repeatedly in cell banking procedures and also to prove absence of production host in the product. Such demands can be fulfilled by a brief method which enables confirmation of strain identity. This communication describes one step identification method for two common Trichoderma species; T. citrinoviride and T. reesei, based on identification of polymorphic region in the nucleotide sequence of translation elongation factor 1 alpha. A unique forward primer and common reverse primer resulted in 153 and 139 bp amplicon for T. citrinoviride and T. reesei, respectively. Simplification was further introduced by using mycelium as template for PCR amplification. Method described in this communication allows rapid, one step identification of two Trichoderma species.
Hodgson, Erin W.; Patterson, Ron
There are many beneficial beetles in Utah besides lady beetles or ladybugs. Beetles can significantly reduce common insect and weed problems and in some cases eliminate the need for chemical control. Examples of beneficial beetles include: ground beetles, rove beetles, tiger beetles and tortoise beetles. Many of these beetles are native to Utah, while others have been purposely introduced to help control damage from exotic insect and weed pests.
Miguel Angel eSalas-Marina
Full Text Available Fungi belonging to the genus Trichoderma, commonly found in soil or colonizing plant roots, exert beneficial effects on plants, including the promotion of growth and the induction of resistance to disease. T. virens and T. atroviride secrete the proteins Sm1 and Epl1, respectively, which elicit local and systemic disease resistance in plants. In this work, we show that these fungi promote growth in tomato (Solanum lycopersicum plants. T. virens was more effective than T. atroviride in promoting biomass gain, and both fungi were capable of inducing systemic protection in tomato against Alternaria solani, Botrytis cinerea, and Pseudomonas syringae pv. tomato (Pst DC3000. Deletion (KO of epl1 in T. atroviride resulted in diminished systemic protection against A. solani and B. cinerea, whereas the T. virens sm1 KO strain was less effective in protecting tomato against Pst DC3000 and B. cinerea. Importantly, over-expression (OE of epl1 and sm1 led to an increase in disease resistance against all tested pathogens. Although the Trichoderma WT strains induced both systemic acquired resistance (SAR- and induced systemic resistance (ISR-related genes in tomato, inoculation of plants with OE and KO strains revealed that Epl1 and Sm1 play a minor role in the induction of these genes. However, we found that Epl1 and Sm1 induce the expression of a peroxidase and an α-dioxygenase encoding genes, respectively, which could be important for tomato protection by Trichoderma spp. Altogether, these observations indicate that colonization by beneficial and/or infection by pathogenic microorganisms dictates many of the outcomes in plants, which are more complex than previously thought.
Porras-Alfaro, Andrea; Bayman, Paul
Endophytes are microorganisms that live within plant tissues without causing symptoms of disease. They are important components of plant microbiomes. Endophytes interact with, and overlap in function with, other core microbial groups that colonize plant tissues, e.g., mycorrhizal fungi, pathogens, epiphytes, and saprotrophs. Some fungal endophytes affect plant growth and plant responses to pathogens, herbivores, and environmental change; others produce useful or interesting secondary metabolites. Here, we focus on new techniques and approaches that can provide an integrative understanding of the role of fungal endophytes in the plant microbiome. Clavicipitaceous endophytes of grasses are not considered because they have unique properties distinct from other endophytes. Hidden from view and often overlooked, endophytes are emerging as their diversity, importance for plant growth and survival, and interactions with other organisms are revealed.
Santoyo, Gustavo; Moreno-Hagelsieb, Gabriel; Orozco-Mosqueda, Ma del Carmen; Glick, Bernard R
Bacterial endophytes ubiquitously colonize the internal tissues of plants, being found in nearly every plant worldwide. Some endophytes are able to promote the growth of plants. For those strains the mechanisms of plant growth-promotion known to be employed by bacterial endophytes are similar to the mechanisms used by rhizospheric bacteria, e.g., the acquisition of resources needed for plant growth and modulation of plant growth and development. Similar to rhizospheric plant growth-promoting bacteria, endophytic plant growth-promoting bacteria can act to facilitate plant growth in agriculture, horticulture and silviculture as well as in strategies for environmental cleanup (i.e., phytoremediation). Genome comparisons between bacterial endophytes and the genomes of rhizospheric plant growth-promoting bacteria are starting to unveil potential genetic factors involved in an endophytic lifestyle, which should facilitate a better understanding of the functioning of bacterial endophytes.
Zhao, Lei; Wang, Fei; Zhang, Yaqing; Zhang, Jiaojiao
Iron (Fe) deficiency is a major plant nutritional disorder in many parts of the world, particularly in areas with saline soils. Among the numerous root-associated microbes that are beneficial for plant nutrient uptake, Trichoderma spp. are the most effective rhizosphere fungi for enhancing plant growth and plant resistance to biotic and abiotic stresses. To investigate the potential mechanisms of action of Trichoderma on insoluble Fe in the soil, which is difficult for plants to absorb and utilize, a high siderophore-producing strain of Trichoderma T6, was isolated from the rhizosphere of cucumber plants. The strain was identified as T. asperellum based on the morphological features and molecular phylogenetic analyses. Applying strain T6 to sterile soil could increase soil levels of Fe(2+) and siderophores, as well as increase Fe(2+) and Fe(3+)-chelate reductase (FCR) activity in cucumber tissues. Purified siderophore eluent (PSE) increased plant growth, thus confirming its role in plant growth promotion. Moreover, extracellular Fe(3+) reducing activity and three kinds of organic acids were detected in the culture filtrate of strain T6. These results indicate that strain T6 influences plant Fe absorption in several ways. Siderophore-based Fe chelation is effective in providing Fe to plants, organic acids, and Fe(3+) reducing enzymes may participate in the solubilization and reduction of insoluble Fe(3+) to Fe(2+).
Pérez, María Laura; Collavino, Mónica Mariana; Sansberro, Pedro Alfonso; Mroginski, Luis Amado; Galdeano, Ernestina
The composition and diversity of the endophytic community associated with yerba mate (Ilex paraguariensis) was investigated using culture-depending methods. Fungi were identified based on their micromorphological characteristics and internal transcribed spacer rDNA sequence analysis; for bacteria 16S rDNA sequence analysis was used. Fungal and bacterial diversity did not show significant differences between organ age. The highest fungal diversity was registered during fall season and the lowest in winter. Bacterial diversity was higher in stems and increased from summer to winter, in contrast with leaves, which decreased. The most frequently isolated fungus was Fusarium, followed by Colletotrichum; they were both present in all the sampling seasons and organ types assayed. Actinobacteria represented 57.5 % of all bacterial isolates. The most dominant bacterial taxa were Curtobacterium and Microbacterium. Other bacteria frequently found were Methylobacterium, Sphingomonas, Herbiconiux and Bacillus. Nitrogen fixation and phosphate solubilization activity, ACC deaminase production and antagonism against plant fungal pathogens were assayed in endophytic bacterial strains. In the case of fungi, strains of Trichoderma, Penicillium and Aspergillus were assayed for antagonism against pathogenic Fusarium sp. All microbial isolates assayed showed at least one growth promoting activity. Strains of Bacillus, Pantoea, Curtobacterium, Methylobacterium, Brevundimonas and Paenibacillus had at least two growth-promoting activities, and Bacillus, Paenibacillus and the three endophytic fungi showed high antagonistic activity against Fusarium sp. In this work we have made a wide study of the culturable endophytic community within yerba mate plants and found that several microbial isolates could be considered as potential inoculants useful for improving yerba mate production.
@@ Trichoderma- based biofungicides are a reality in commercial agriculture, with more than 50formulations registered worldwide as biopesticides or biofertilizers. Several research strategies have been applied to identify the main genes and compounds involved in the complex, three-way interactions between fungal antagonists, plants and microbial pathogens. Proteome and genome analyses have greatly enhanced our ability to conduct targeted and genome-based functional studies. We have obtained reproducible 2-D maps of the entire fungal proteome in various conditions of interaction,which permitted the isolation of many proteins related to specific functions. Many differential proteins from several biocontrol strains of Trichoderma spp. during the in vivo interaction with different plants and/or several phytopathogenic fungi have been isolated and analyzed by MALDI-TOF.Relevant genes have been cloned and specifically inactivated, to demonstrate their function in biocontrol and induction of disease resistance. GFP-based reporter systems with interaction-inducible promoters allowed the characterization of regulatory sequences activated by the presence of the pathogen or the plant. From extensive cDNA and EST libraries of genes expressed during Trichoderma-pathogen-plant interactions, we are identified and determined the role of a variety of novel genes and gene-products, including ABC transporters specifically induced during antagonism with other microbes; enzymes and other proteins that produce or act as novel elicitors of Induced Resistance in plant and promote root growth and crop yield; proteins possibly responsible of a gene-forgene avirulent interaction between Trichoderma and plants; mycoparasitism-related inducers released from fungal pathogens and that activate biocontrol in Trichoderma; fungal promoters specifically induced during mycoparasitism and plant colonization; plant proteins and a novel phytoalexin induced by the presence of the fungal antagonist; etc
Syranidou, Evdokia; Christofilopoulos, Stavros; Gkavrou, Georgia; Thijs, Sofie; Weyens, Nele; Vangronsveld, Jaco; Kalogerakis, Nicolas
This study investigated the potential of indigenous endophytic bacteria to improve the efficiency of the wetland helophyte Juncus acutus to deal with a mixed pollution consisting of emerging organic contaminants (EOCs) and metals. The beneficial effect of bioaugmentation with selected endophytic bacteria was more prominent in case of high contamination: most of the inoculated plants (especially those inoculated with the mixed culture) removed higher percentages of organics and metals from the liquid phase in shorter times compared to the non-inoculated plants without exhibiting significant oxidative stress. When exposed to the lower concentrations, the tailored mixed culture enhanced the performance of the plants to decrease the organics and metals from the water. The composition of the root endophytic community changed in response to increased levels of contaminants while the inoculated bacteria did not modify the community structure. Our results indicate that the synergistic relationships between endophytes and the macrophyte enhance plants' performance and may be exploited in constructed wetlands treating water with mixed contaminations. Taking into account that the concentrations of EOCs used in this study are much higher than the average contents of typical wastewaters, we can conclude that the macrophyte J. acutus with the aid of a mixed culture of tailored endophytic bacteria represents a suitable environmentally friendly alternative for treating pharmaceuticals and metals.
Rasche, Frank; Lueders, Tillmann; Schloter, Michael; Schaefer, Sabine; Buegger, Franz; Gattinger, Andreas; Hood-Nowotny, Rebecca C; Sessitsch, Angela
A (13)CO2 (99 atom-%, 350 ppm) incubation experiment was performed to identify active bacterial endophytes in two cultivars of Solanum tuberosum, cultivars Desirée and Merkur. We showed that after the assimilation and photosynthetic transformation of (13)CO2 into (13)C-labeled metabolites by the plant, the most directly active, cultivar specific heterotrophic endophytic bacteria that consume these labeled metabolite scan be identified by DNA stable isotope probing (DNA-SIP).Density-resolved DNA fractions obtained from SIP were subjected to 16S rRNA gene-based community analysis using terminal restriction fragment length polymorphism analysis and sequencing of generated gene libraries.Community profiling revealed community compositions that were dominated by plant chloroplast and mitochondrial 16S rRNA genes for the 'light' fractions of (13)CO2-incubated potato cultivars and of potato cultivars not incubated with (13)CO2. In the 'heavy' fractions of the (13)CO2-incubated endophyte DNA, a bacterial 492-bp terminal restriction fragment became abundant, which could be clearly identified as Acinetobacter and Acidovorax spp. in cultivars Merkur and Desirée,respectively, indicating cultivar-dependent distinctions in (13)C-label flow. These two species represent two common potato endophytes with known plant-beneficial activities.The approach demonstrated the successful detection of active bacterial endophytes in potato. DNA-SIP therefore offers new opportunities for exploring the complex nature of plant-microbe interactions and plant-dependent microbial metabolisms within the endosphere.
Full Text Available Trichoderma strains that are beneficial to both the growth and health of plants can be used as plant growth-promoting fungi (PGPF or biological control agents (BCA in agricultural and horticultural practices. In order to select PGPF or BCA strains, their biological properties and taxonomy must be carefully studied. In this study, 104 strains of Trichoderma collected at geographically different locations in Poland for selection as PGPF or BCA were identified by DNA barcoding, based on the sequences of internal transcribed spacers 1 and 2 (ITS1 and 2 of the ribosomal RNA gene cluster and on the sequences of translation elongation factor 1 alpha (tef1, chitinase 18-5 (chi18-5, and RNA polymerase II subunit (rpb2 gene fragments. Most of the strains were classified as: T. atroviride (38%, T. harzianum (21%, T. lentiforme (9%, T. virens (9%, and T. simmonsii (6%. Single strains belonging to T. atrobrunneum, T. citrinoviride, T. crassum, T. gamsii, T. hamatum, T. spirale, T. tomentosum, and T. viridescens were identified. Three strains that are potentially pathogenic to cultivated mushrooms belonging to T. pleuroticola and T. aggressivum f. europaeum were also identified. Four strains: TRS4, TRS29, TRS33, and TRS73 were classified to Trichoderma spp. and molecular identification was inconclusive at the species level. Phylogeny analysis showed that three of these strains TRS4, TRS29, and TRS33 belong to Trichoderma species that is not yet taxonomically established and strain TRS73 belongs to the T. harzianum complex, however, the species could not be identified with certainty.
Busby, Posy E; Ridout, Mary; Newcombe, George
Many recent studies have demonstrated that non-pathogenic fungi within plant microbiomes, i.e., endophytes ("endo" = within, "phyte" = plant), can significantly modify the expression of host plant disease. The rapid pace of advancement in endophyte ecology warrants a pause to synthesize our understanding of endophyte disease modification and to discuss future research directions. We reviewed recent literature on fungal endophyte disease modification, and here report on several emergent themes: (1) Fungal endophyte effects on plant disease span the full spectrum from pathogen antagonism to pathogen facilitation, with pathogen antagonism most commonly reported. (2) Agricultural plant pathosystems are the focus of research on endophyte disease modification. (3) A taxonomically diverse group of fungal endophytes can influence plant disease severity. And (4) Fungal endophyte effects on plant disease severity are context-dependent. Our review highlights the importance of fungal endophytes for plant disease across a broad range of plant pathosystems, yet simultaneously reveals that complexity within plant microbiomes presents a significant challenge to disentangling the biotic environmental factors affecting plant disease severity. Manipulative studies integrating eco-evolutionary approaches with emerging molecular tools will be poised to elucidate the functional importance of endophytes in natural plant pathosystems that are fundamental to biodiversity and conservation.
Dupont, Pierre-Yves; Eaton, Carla J; Wargent, Jason J; Fechtner, Susanne; Solomon, Peter; Schmid, Jan; Day, Robert C; Scott, Barry; Cox, Murray P
Beneficial associations between plants and microbes play an important role in both natural and agricultural ecosystems. For example, associations between fungi of the genus Epichloë, and cool-season grasses are known for their ability to increase resistance to insect pests, fungal pathogens and drought. However, little is known about the molecular changes induced by endophyte infection. To study the impact of endophyte infection, we compared the expression profiles, based on RNA sequencing, of perennial ryegrass infected with Epichloë festucae with noninfected plants. We show that infection causes dramatic changes in the expression of over one third of host genes. This is in stark contrast to mycorrhizal associations, where substantially fewer changes in host gene expression are observed, and is more similar to pathogenic interactions. We reveal that endophyte infection triggers reprogramming of host metabolism, favouring secondary metabolism at a cost to primary metabolism. Infection also induces changes in host development, particularly trichome formation and cell wall biogenesis. Importantly, this work sheds light on the mechanisms underlying enhanced resistance to drought and super-infection by fungal pathogens provided by fungal endophyte infection. Finally, our study reveals that not all beneficial plant-microbe associations behave the same in terms of their effects on the host.
Full Text Available The community of endophytic fungi associated with Acer ginnala, a common tree in northeastern China, was investigated. Four media, PDA, Czapek's, WA and Sabouraud's, were used to inoculate explants from seeds, annual twigs and perennial twigs (xylem and bark. Media strongly affected the isolated species number, but not colonization frequency (CF or isolation frequency (IF. To investigate media effect further, a Principal Component Analysis (PCA was done. As a result, two components accounted for 86.502% of the total variance were extracted. These two components were named as PDA-determined factor (accounted for 45.139% of the total variance and Czapek's-determined factor (accounted for 41.363% of the total variance, respectively. This result suggested that only two media, PDA and Czapek's, could be used instead of all four media in this study without affecting the isolation results significantly. In total, ten taxa were isolated in this study. Alternaria sp., Phomopsis sp., Neurospora sp. and Phoma sp. were dominant endophytes while Pleosporales Incertae Sedis sp., Cladosporium sp., Trichoderma sp. and Epicoccum sp. were rare taxa. Different tissues/organs had different endophyte assemblages. All tissue/organ pairs had low Bray-Curtis indices (<0.3 except for bark and annual twigs (0.63. Compared to perennial twigs, annual twigs had a lower taxon number, lower isolate number, lower endophyte dominance and diversity indices. Seeds had distinct assemblage, lower similarity and similar low diversity indices to annual twigs. These results suggested that tissue type determines the endophyte assemblage while age determines the diversity.
Marchant, Mary A.; Murrell, Courtney Paige; Zhuang, Jun
Cattle consuming tall fescue pastures infected with the endophyte Neotyphodium coenophialum often suffer physiological disorders that reduce animal performance. One solution is to replace endophyte-infected tall fescue pastures with an endophyte-free mixture. A benefit-cost analysis was conducted to determine the profitability of pasture restoration. The profitability of this action depends on the percentage of endophyte in existing pastures, the discount rate, and the stand life of the endop...
Doni, Febri; Anizan, I.; Che Radziah C. M., Z.; Yusoff, Wan Mohtar Wan
Trichoderma spp. are considered as successful plant growth promoting fungi and have positive role in habitat engineering. In this study, the potential for Trichoderma spp. to regulate transpiration process in rice plant was assessed experimentally under greenhouse condition using a completely randomized design. The study revealed that Trichoderma spp. have potential to enhance growth of rice plant through transpirational processes. The results of the study add to the advancement of the understanding as to the role of Trichoderma spp. in improving rice physiological process.
Fungal endophytes were isolated from four species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, eight within the Ascomycota and four within the Basidiomycota, were identified based on PCR amplification and sequencing ...
Alyssa Ann Carrell
Full Text Available Conifers predominantly occur on soils or in climates that are suboptimal for plant growth. This is generally attributed to symbioses with mycorrhizal fungi and to conifer adaptations, but recent experiments suggest that aboveground endophytic bacteria in conifers fix nitrogen (N and affect host shoot tissue growth. Because most bacteria cannot be grown in the laboratory very little is known about conifer-endophyte associations in the wild. Pinus flexilis (limber pine and Picea engelmannii (Engelmann spruce growing in a subalpine, nutrient-limited environment are potential candidates for hosting endophytes with roles in N2 fixation and abiotic stress tolerance. We used 16S rRNA pyrosequencing to ask whether these conifers host a core of bacterial species that are consistently associated with conifer individuals and therefore potential mutualists. We found that while overall the endophyte communities clustered according to host species, both conifers were consistently dominated by the same phylotype, which made up 19-53% and 14-39% of the sequences in P. flexilis and P. engelmannii respectively. This phylotype is related to Gluconacetobacter diazotrophicus and other N2 fixing acetic acid bacterial endophytes. The pattern observed for the P. flexilis and P. engelmannii needle microbiota—a small number of major species that are consistently associated with the host across individuals and species—is unprecedented for an endophyte community, and suggests a specialized beneficial endophyte function. One possibility is endophytic N fixation, which could help explain how conifers can grow in severely nitrogen-limited soil, and why some forest ecosystems accumulate more N than can be accounted for by known nitrogen input pathways.
Carrell, Alyssa A; Frank, Anna C
Conifers predominantly occur on soils or in climates that are suboptimal for plant growth. This is generally attributed to symbioses with mycorrhizal fungi and to conifer adaptations, but recent experiments suggest that aboveground endophytic bacteria in conifers fix nitrogen (N) and affect host shoot tissue growth. Because most bacteria cannot be grown in the laboratory very little is known about conifer-endophyte associations in the wild. Pinus flexilis (limber pine) and Picea engelmannii (Engelmann spruce) growing in a subalpine, nutrient-limited environment are potential candidates for hosting endophytes with roles in N2 fixation and abiotic stress tolerance. We used 16S rRNA pyrosequencing to ask whether these conifers host a core of bacterial species that are consistently associated with conifer individuals and therefore potential mutualists. We found that while overall the endophyte communities clustered according to host species, both conifers were consistently dominated by the same phylotype, which made up 19-53% and 14-39% of the sequences in P. flexilis and P. engelmannii, respectively. This phylotype is related to Gluconacetobacter diazotrophicus and other N2 fixing acetic acid bacterial endophytes. The pattern observed for the P. flexilis and P. engelmannii needle microbiota-a small number of major species that are consistently associated with the host across individuals and species-is unprecedented for an endophyte community, and suggests a specialized beneficial endophyte function. One possibility is endophytic N fixation, which could help explain how conifers can grow in severely nitrogen-limited soil, and why some forest ecosystems accumulate more N than can be accounted for by known nitrogen input pathways.
Wu, Lianjie; Ren, Anzhi; Jing, Yuanfang; Zhou, Yong; Wang, Xinyu; Qin, Junhua; Gao, Yubao
Leaf endophytes such as Epichloë can affect the competitive ability of host grasses, but the reported responses are inconsistent. We hypothesized that this inconsistency is caused, at least in part, by the following two aspects. One is that a competitive advantage might occur as a result of an increase in storage compounds for both growth and defense. Another is that the effect of the endophyte might be related to both water availability and host density. In a greenhouse experiment, we compared the competitive abilities of endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis, a dominant grass native to the Inner Mongolia Steppe of China, subjected to ten treatments comprised of a factorial combination of two levels of water availability (well-watered and drought) and five proportions of EI to EF plants (12:0, 4:8, 6:6, 8:4, 0:12). The results showed that the competitive ability of EI plants was higher than that of EF under drought. Here, greater belowground biomass and water use efficiency might contribute to better competitiveness of EI plants. When competing under well-watered conditions, endophyte infection did not provide a benefit to the host plant in biomass accumulation, but more carbon was allocated to defense (total phenolics) in EI plants. This scenario could help EI plants suffer less damage than EF when exposed to herbivores in natural habitats. The competitive ability of EI plants was regulated by EI:EF ratios. Competitive ability of EI plants was higher than that of EF plants in mixtures with lower numbers of EI plants, but the beneficial effect of endophyte infection was neutralized in mixtures with higher numbers of EI plants. Overall, endophyte infection improved the competitive ability of the host under either drought or well-watered conditions but in the presence of herbivore, only this benefit was neutralized by increasing ratios of EI plants. We suspect that both the conditional beneficial effects and stabilizing effects of density
Liron-Espana, Carmen; Lopez, Rigoberto A.
This paper separates market power and efficiency effects of concentration in a sample of 255 U.S. manufacturing industries and computes welfare changes from rises in concentration. The empirical findings reveal that in nearly two-third of the cases, consumers lose as efficiency gains are generally pocketed by the industries. From an aggregate welfare standpoint, concentration is found to be beneficial in nearly 70% of the cases, mostly for low and moderate levels of concentration being partic...
Compant, Stéphane; van der Heijden, Marcel G A; Sessitsch, Angela
It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO(2), drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate change. Here, we review the results of 135 studies investigating the effects of climate change factors on beneficial microorganisms and their interaction with host plants. The majority of studies showed that elevated CO(2) had a positive influence on the abundance of arbuscular and ectomycorrhizal fungi, whereas the effects on plant growth-promoting bacteria and endophytic fungi were more variable. In most cases, plant-associated microorganisms had a beneficial effect on plants under elevated CO(2). The effects of increased temperature on beneficial plant-associated microorganisms were more variable, positive and neutral, and negative effects were equally common and varied considerably with the study system and the temperature range investigated. Moreover, numerous studies indicated that plant growth-promoting microorganisms (both bacteria and fungi) positively affected plants subjected to drought stress. Overall, this review shows that plant-associated microorganisms are an important factor influencing the response of plants to climate change.
Wani, Zahoor Ahmed; Ashraf, Nasheeman; Mohiuddin, Tabasum; Riyaz-Ul-Hassan, Syed
Endophytism is the phenomenon of mutualistic association of a plant with a microorganism wherein the microbe lives within the tissues of the plant without causing any symptoms of disease. In addition to being a treasured biological resource, endophytes play diverse indispensable functions in nature for plant growth, development, stress tolerance, and adaptation. Our understanding of endophytism and its ecological aspects are overtly limited, and we have only recently started to appreciate its essence. Endophytes may impact plant biology through the production of diverse chemical entities including, but not limited to, plant growth hormones and by modulating the gene expression of defense and other secondary metabolic pathways of the host. Studies have shown differential recruitment of endophytes in endophytic populations of plants growing in the same locations, indicating host specificity and that endophytes evolve in a coordinated fashion with the host plants. Endophytic technology can be employed for the efficient production of agricultural and economically important plants and plant products. The rational application of endophytes to manipulate the microbiota, intimately associated with plants, can help in enhancement of production of agricultural produce, increased production of key metabolites in medicinal and aromatic plants, as well as adaption to new bio-geographic regions through tolerance to various biotic and abiotic conditions. However, the potential of endophytic biology can be judiciously harnessed only when we obtain insight into the molecular mechanism of this unique mutualistic relationship. In this paper, we present a discussion on endophytes, endophytism, their significance, and diverse functions in nature as unraveled by the latest research to understand this universal natural phenomenon.
Hiruma, Kei; Gerlach, Nina; Sacristán, Soledad; Nakano, Ryohei Thomas; Hacquard, Stéphane; Kracher, Barbara; Neumann, Ulla; Ramírez, Diana; Bucher, Marcel; O’Connell, Richard J.; Schulze-Lefert, Paul
Summary A staggering diversity of endophytic fungi associate with healthy plants in nature, but it is usually unclear whether these represent stochastic encounters or provide host fitness benefits. Although most characterized species of the fungal genus Colletotrichum are destructive pathogens, we show here that C. tofieldiae (Ct) is an endemic endophyte in natural Arabidopsis thaliana populations in central Spain. Colonization by Ct initiates in roots but can also spread systemically into shoots. Ct transfers the macronutrient phosphorus to shoots, promotes plant growth, and increases fertility only under phosphorus-deficient conditions, a nutrient status that might have facilitated the transition from pathogenic to beneficial lifestyles. The host’s phosphate starvation response (PSR) system controls Ct root colonization and is needed for plant growth promotion (PGP). PGP also requires PEN2-dependent indole glucosinolate metabolism, a component of innate immune responses, indicating a functional link between innate immunity and the PSR system during beneficial interactions with Ct. PMID:26997485
Hiruma, Kei; Gerlach, Nina; Sacristán, Soledad; Nakano, Ryohei Thomas; Hacquard, Stéphane; Kracher, Barbara; Neumann, Ulla; Ramírez, Diana; Bucher, Marcel; O'Connell, Richard J; Schulze-Lefert, Paul
A staggering diversity of endophytic fungi associate with healthy plants in nature, but it is usually unclear whether these represent stochastic encounters or provide host fitness benefits. Although most characterized species of the fungal genus Colletotrichum are destructive pathogens, we show here that C. tofieldiae (Ct) is an endemic endophyte in natural Arabidopsis thaliana populations in central Spain. Colonization by Ct initiates in roots but can also spread systemically into shoots. Ct transfers the macronutrient phosphorus to shoots, promotes plant growth, and increases fertility only under phosphorus-deficient conditions, a nutrient status that might have facilitated the transition from pathogenic to beneficial lifestyles. The host's phosphate starvation response (PSR) system controls Ct root colonization and is needed for plant growth promotion (PGP). PGP also requires PEN2-dependent indole glucosinolate metabolism, a component of innate immune responses, indicating a functional link between innate immunity and the PSR system during beneficial interactions with Ct.
Zhang, Yanyan; Han, Ting; Ming, Qianliang; Wu, Lingshang; Rahman, Khalid; Qin, Luping
In recent years, a number of alkaloids have been discovered from endophytic fungi in plants, which exhibited excellent biological properties such as antimicrobial, insecticidal, cytotoxic, and anticancer activities. This review mainly deals with the research progress on endophytic fungi for producing bioactive alkaloids such as quinoline and isoquinoline, amines and amides, indole derivatives, pyridines, and quinazolines. The biological activities and action mechanisms of these alkaloids from endophytic fungi are also introduced. Furthermore, the relationships between alkaloid-producing endophytes and their host plants, as well as their potential applications in the future are discussed.
Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie
The efficacy of seven strains of Trichoderma asperellum collected from the fields in Southern China was assessed against Fusarium graminearum (FG) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain. The key factors of antagonist activity were attributed to a total of 13 factors including cell wall degrading enzymes (chitnase, protease and β-glucanases), secondary metabolites and peptaibols and these were analyzed from eight strains of Trichoderma. A linear regression model demonstrated that interaction of enzymes and secondary metabolites of T. asperellum strain ZJSX5003 enhanced the antagonist activity against FG. Further, this strain displayed a disease reduction of 71 % in maize plants inoculated with FG compared to negative control. Pointing out that the T. asperellum strain ZJSX5003 is a potential source for the development of a biocontrol agent against corn stalk rot.
Woo S L; Lorito M; Formisano E; Fogliano V; Cosenza C; Mauro A; Turrà D; Soriente I; Ferraioli S; Scala F
@@ Trichoderma atroviride strain P1 has been used extensively to study the mycoparasitic mechanisms in the interaction between plant pathogenic host and beneficial antagonistic fungi. Mutants of P1 containing the green fluorescent protein (gfp) or glucose oxidase (gox) reporter systems and different inducible promoters (from the exochitinase nag1 gene, or the endochitinase ech42 gene of P1) were used to determine the factors that activate the biocontrol gene expression cascade in the antagonist. The following compounds were tested singly and in various combinations: purified Trichoderma P1 enzymes (endochitinase, exochitinase, chitobiosidase,glucanase); antagonist culture filtrates (T. atroviride P1 wild-type and relative knock-out mutants, T.harzianum, T. reesei); pathogen culture filtrates (Botrytis, Pythium, Rhizoctonia); purified fungal cell walls (CWs) from Trichoderma , Botrytis, Pythium, Rhizoctonia; colloidal crab shell chitin; and plant extracts from cucumber leaves, stems or roots. Strong induction of mycoparasitism was found with the various digestion products produced by treating fungal CWs and colloidal chitin with purified enzymes or fungal culture filtrates. Filtrates from chitinase knock-out mutants, as well as CWs from Oomycetes fungi, were less active in producing the stimulus for mycoparasitism. The host CW digestion products were separated by molecular weight (MW) to determine which compounds were able to activate Trichoderma. Micromolecules of MW less than 3 kDa were found to trigger mycoparasitism gene expression before physical contact with the host pathogen. These compounds stimulated mycelial growth and spore germination of the antagonist. Purification of these host-derived compounds was conducted by HPLC and in vivo assay. The obtained inducers were able to stimulate both the production of endochitinase and exochitinase enzymes, even under repressing conditions in the presence of glucose. Inducers stimulated the biocontrol effect of P1 in
... 7 Agriculture 3 2010-01-01 2010-01-01 false Fungal endophyte test. 201.58d Section 201.58d... REGULATIONS Examinations in the Administration of the Act § 201.58d Fungal endophyte test. A fungal endophyte test may be used to determine the amount of fungal endophyte (Acremonium spp.) in certain grasses....
Zhu, Z.X.; Zhuang, W.Y.
Stromata of Trichoderma species having green ascospores were collected in various regions of China. Based on morphology of the sexual and asexual morph, culture characteristics, and sequence analyses of rpb2 and tef1 genes, 17 species with green ascospores were identified. Among them, Trichoderma ro
Nicolás, Carlos; Hermosa, Rosa; Rubio, Belén; Mukherjee, Prasun K; Monte, Enrique
Many filamentous fungi from the genus Trichoderma are well known for their anti-microbial properties. Certain genes from Trichoderma spp. have been identified and transferred to plants for improving biotic and abiotic stress tolerance, as well for applications in bioremediation. Several Trichoderma genomes have been sequenced and many are in the pipeline, facilitating high throughput gene analysis and increasing the availability of candidate transgenes. This, coupled with improved plant transformation systems, is expected to usher in a new era in plant biotechnology where several genes from these antagonistic fungi can be transferred into plants to achieve enhanced stress tolerance, bioremediation activity, herbicide tolerance, and reduction of phytotoxins. In this review, we illustrate the major achievements made by transforming plants with Trichoderma genes as well as their possible mode of action. Moreover, examples of efficient application of genetically modified plants as biofactories to produce active Trichoderma enzymes are indicated.
Full Text Available The purpose of this study was to investigate the diversity of endophytic fungi of Aralia elata distributed in Northeast China as well as their capacity to produce saponins. Ninety-six strains of endophytic fungi were isolated, and polymerase chain reaction (PCR and sequencing were employed to identify the isolates. The saponin concentrations of the culture filtrates of representative strains were measured. The agar diffusion method was used to test antimicrobial activity, while high-performance liquid chromatography (HPLC was employed to identify the saponins produced by representative strains. Alternaria, Botryosphaeria, Camarosporium, Cryptosporiopsis, Diaporthe, Dictyochaeta, Penicillium, Fusarium, Nectria, Peniophora, Schizophyllum, Cladosporium and Trichoderma species were isolated in this study. Overall, 25% of the isolates belonged to Diaporthe (Diaporthe eres, and 12.5% belonged to Alternaria. The highest concentration of saponins was produced by G22 (2.049 mg/mL. According to the results of the phylogenetic analysis, G22 belonged to the genus Penicillium. The culture filtrate of G22 exhibited antibacterial activity against Staphylococcus aureus, and ginsenosides Re and Rb2 were detected in G22 culture filtrates by HPLC.
Wu, Hao; Yang, Hongyan; You, Xiangling; Li, Yuhua
The purpose of this study was to investigate the diversity of endophytic fungi of Aralia elata distributed in Northeast China as well as their capacity to produce saponins. Ninety-six strains of endophytic fungi were isolated, and polymerase chain reaction (PCR) and sequencing were employed to identify the isolates. The saponin concentrations of the culture filtrates of representative strains were measured. The agar diffusion method was used to test antimicrobial activity, while high-performance liquid chromatography (HPLC) was employed to identify the saponins produced by representative strains. Alternaria, Botryosphaeria, Camarosporium, Cryptosporiopsis, Diaporthe, Dictyochaeta, Penicillium, Fusarium, Nectria, Peniophora, Schizophyllum, Cladosporium and Trichoderma species were isolated in this study. Overall, 25% of the isolates belonged to Diaporthe (Diaporthe eres), and 12.5% belonged to Alternaria. The highest concentration of saponins was produced by G22 (2.049 mg/mL). According to the results of the phylogenetic analysis, G22 belonged to the genus Penicillium. The culture filtrate of G22 exhibited antibacterial activity against Staphylococcus aureus, and ginsenosides Re and Rb2 were detected in G22 culture filtrates by HPLC.
Chen, Juan; Wang, Hui; Guo, Shun-Xing
The seed germination of orchids under natural conditions requires association with mycorrhizal fungi. Dendrobium nobile and Dendrobium chrysanthum are threatened orchid species in China where they are considered medicinal plants. For conservation and application of Dendrobium using symbiosis technology, we isolated culturable endophytic and mycorrhizal fungi colonized in the protocorms and adult roots of two species plants and identified them by morphological and molecular analyses (5.8S and nrLSU). Of the 127 endophytic fungi isolated, 11 Rhizoctonia-like strains were identified as Tulasnellales (three strains from protocorms of D. nobile), Sebacinales (three strains from roots of D. nobile and two strains from protocorms of D. chrysanthum) and Cantharellales (three strains from roots of D. nobile), respectively. In addition, species of Xylaria, Fusarium, Trichoderma, Colletotrichum, Pestalotiopsis, and Phomopsis were the predominant non-mycorrhizal fungi isolated, and their probable ecological roles in the Dendrobium plants are discussed. These fungal resources will be of great importance for the large-scale cultivation of Dendrobium plants using symbiotic germination technology and for the screening of bioactive metabolites from them in the future.
Abbreviations used: IR: Infrared Radiation, HR-ESI-MS: High resolution electrospray ionization mass spectroscopy, LCMS-IT-TOF: Liquid chromatography mass spectroscopy-Ion trap-Time-of-flight, UV: Ultraviolet-visible, HMBC: Heteronuclear multiple bond correlation, NOE: Nuclear Overhauser effect.
Full Text Available Com a utilização de plantas medicinais em infusões, xaropes, tinturas, ungüentos, dentre outras formas, pressupõe-se que fungos endofíticos, presentes no interior das plantas, mas sem causar doença, possam tornar-se um componente destes produtos, principalmente quando utilizados in natura. Além disso, os fungos endofíticos podem também produzir substâncias tóxicas aos usuários ou mesmo alterar o metabolismo vegetal, modificando a composição e as propriedades medicinais, assim como, a qualidade do produto armazenado e comercializado. Neste sentido, objetivou-se isolar e identificar a flora fúngica endofítica de onze espécies medicinais escolhidas ao acaso. Obtiveram-se culturas-puras dos fungos Phomopsis, Colletotrichum, Pestalotia, Trichoderma, Fusarium, Nigrospora e Glomerella ocorrendo endofiticamente em Plectranthus barbatus, Vernonia condensata, Pfaffia paniculata, Foeniculum vulgare, Cymbopogon citratus, Cymbopogon nardus, Cordia curassavica, Maytenus ilicifolia, Punica granatum, Morus nigra e Bauhinia forficata. As espécies vegetais em que se identificaram o maior número de fungos endofíticos foram Vernonia condensata, Punica granatum e Morus nigra. Todos os fungos recuperados neste trabalho apresentaram características estritamente endofíticas, não manifestando patogenicidade nas espécies hospedeiras. Dentre os fungos detectados, especial atenção deve ser dada ao gênero Fusarium, uma vez que inúmeras espécies deste gênero são conhecidas produtoras de micotoxinas e constituem-se em importantes patógenos pós-colheita.With the use of medicinal plants in infusions, syrups, dyes, unguents, among other forms, it is expected that endophytic fungi, present inside the plants but not causing diseases, become components of these products, especially when used in natura. In addition, endophytic fungi can produce toxic substances to the users or even modify the plant metabolism, altering the medicinal composition and
Vasundhara, M.; Anil Kumar; M. Sudhakara Reddy
Endophytic fungi are capable of producing plant associated metabolites and their analogs with therapeutic value. In order to identify the potential endophytic isolates producing bioactive compounds, one need to screen all isolated endophytes, which may run into hundreds. Isolation of endophytic fungi is relatively a simple process; but screening of the isolated fungi for required metabolite production is a cumbersome process. Endophytic fungi producing plant associated metabolites may contain...
Plants form mutualistic symbioses with a variety of microorganisms, including endophytic fungi that live inside the plant and cause no symptoms of infection. Some endophytic fungi form defensive mutualisms based on the production of bioactive metabolites that protect the plant from herbivores in exc...
Di Pierro, G B; Tartaglia, N; Aresu, L
To analyze feasibility and outcomes of laparoscopic partial nephrectomy (LPN) for endophytic hilar tumors in low-intermediate (ASA I-II) risk patients.......To analyze feasibility and outcomes of laparoscopic partial nephrectomy (LPN) for endophytic hilar tumors in low-intermediate (ASA I-II) risk patients....
Tall fescue is extremely persistent and productive in the climatic and soil conditions in the fescue belt, which makes it extremely challenging to replace toxic endophyte-infected tall fescue with non-toxic grass alternatives. There is another option, which is to replace toxic endophyte-infected ta...
Full Text Available We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%, release ammonium (39%, secrete siderophores (38% and a limited part of them synthetized IAA and IAA-like molecules (5%. Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards.
Baldan, Enrico; Nigris, Sebastiano; Romualdi, Chiara; D'Alessandro, Stefano; Clocchiatti, Anna; Zottini, Michela; Stevanato, Piergiorgio; Squartini, Andrea; Baldan, Barbara
We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards.
Rodriguez, R.J.; White, J.F.; Arnold, A.E.; Redman, R.S.
All plants in natural ecosystems appear to be symbiotic with fungal endophytes. This highly diverse group of fungi can have profound impacts on plant communities through increasing fitness by conferring abiotic and biotic stress tolerance, increasing biomass and decreasing water consumption, or decreasing fitness by altering resource allocation. Despite more than 100 yr of research resulting in thousands of journal articles, the ecological significance of these fungi remains poorly characterized. Historically, two endophytic groups (clavicipitaceous (C) and nonclavicipitaceous (NC)) have been discriminated based on phylogeny and life history traits. Here, we show that NC-endophytes represent three distinct functional groups based on host colonization and transmission, in planta biodiversity and fitness benefits conferred to hosts. Using this framework, we contrast the life histories, interactions with hosts and potential roles in plant ecophysiology of C- and NC-endophytes, and highlight several key questions for future work in endophyte biology.
Zhang, Xinjian; Harvey, Paul R; Stummer, Belinda E; Warren, Rosemary A; Zhang, Guangzhi; Guo, Kai; Li, Jishun; Yang, Hetong
Trichoderma afroharzianum is one of the best characterized Trichoderma species, and strains have been utilized as plant disease suppressive inoculants. In contrast, Trichoderma gamsii has only recently been described, and there is limited knowledge of its disease suppressive efficacies. Comparative studies of changes in gene expression during interactions of these species with their target plant pathogens will provide fundamental information on pathogen antibiosis functions. In the present study, we used complementary DNA amplified fragment length polymorphism (cDNA-AFLP) analysis to investigate changes in transcript profiling of T. afroharzianum strain LTR-2 and T. gamsii strain Tk7a during in vitro interactions with plant pathogenic Rhizoctonia solani and Pythium irregulare. Considerable differences were resolved in the overall expression profiles of strains LTR-2 and Tk7a when challenged with either plant pathogen. In strain LTR-2, previously reported mycoparasitism-related genes such as chitinase, polyketide synthase, and non-ribosomal peptide synthetase were found to be differentially expressed. This was not so for strain Tk7a, with the only previously reported antibiosis-associated genes being small secreted cysteine-rich proteins. Although only one differentially expressed gene was common to both strains LTR-2 and Tk7a, numerous genes reportedly associated with pathogen antibiosis processes were differentially expressed in both strains, including degradative enzymes and membrane transport proteins. A number of novel potential antibiosis-related transcripts were found from strains LTR-2 and Tk7a and remain to be identified. The expression kinetics of 20 Trichoderma (10 from strain LTR-2, 10 from strain Tk7a) transcript-derived fragments (TDFs) were quantified by quantitative reverse transcription PCR (RT-qPCR) at pre- and post-mycelia contact stages of Trichoderma-prey interactions, thereby confirming differential gene expression. Collectively, this research
Lobanok, A G; Pavlovskaia, Zh I
The induction of cellulase synthesis by lactose was studied in the resting cells of Trichoderma lignorum OM 534. The effect depended on the concentration of lactose, pH, and the age of the mycelium. The induction of the enzyme synthesis by lactose is supressed by glucose and its metabolites. The repression by glucose is partly eliminated by Cyk 3'-5'-AMP, theophylline, and coffeine. The induction of cellulase by lactose is regarded as a derepression of the synthesis of this enzyme as a result of slow assimilation of the disaccharide. The synthesis of cellulase in T. lignorum is presumed to be constitutive.
Johanna Steyaert; Travis Glare; Alison Stewart; Margaret Carpenter; Hayley Ridgway
@@ Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival,whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride.These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderrma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response.Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1 , which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting
Casas S; Cortés C; Ríos M; Rosales T; Bibbins M; Olmedo V; Herrera-Estrella A
@@ Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to conidiate upon exposure to light. In total darkness, T. atroviride grows indefinitely as a mycelium provided that nutrients are not limiting. However, nutrient deprivation and light trigger the conidiation process. A pulse of blue light given to a radially growing colony induces synchronous sporulation. A ring of conidiophores bearing green conidia is produced at what had been the colony perimeter at the time of the light pulse. All known responses to blue light in N. crassa are initiated by a couple of transcription factors encoded by the white-collar genes (wc -1 and wc-2). WC-1 and WC-2 bind to the promoters of light regulated genes to rapidly activate transcription in response to light. In T. atroviride the photolyase encoding gene phr1 undergoes fast transcriptional activation in response to light. The presence of putative WCC binding boxes in the promoter of phr1 , suggested that light responses in Trichoderma could be under the control of white-collar homologues. We cloned two genes and demonstrated by gene replacement that both are essential for photoconidiation and photolyase gene expression. Therefore, they were named blue-light regulator one and two (blr1 and blr2 ). The BLR1 protein has all the characteristics of a blue-light photoreceptor. The generation of subtractive cDNA libraries allowed us to identify novel, BLR independent, light responses including the regulation of gene expression by blue-light. In addition, we recently initiated a Trichoderma ESTs sequencing project. Until now, we have sequenced above 3000 ESTs, from which we have obtained approximately 1800 unigenes. This unigene set was printed in microarrays and used to search for light induced genes. Twenty five clearly induced and around thirty repressed genes have been
Jones, Paetrice O; Vasudevan, Palligarnai T
Cellulose hydrolysis by immobilized Trichoderma reesei cellulase in the presence of a low viscosity ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-DEP), was investigated. Preparation of the carrier-free immobilized cellulase was optimized with respect to concentration of the cross-linker and the type of precipitant. The addition of 2% (v/v) EMIM-DEP during hydrolysis gave an initial reaction rate 2.7 times higher than the hydrolysis rate with no ionic liquid. The initial yield after 2 h was 0.7 g glucose/g cellulose, and the carrier-free immobilized cellulase (CFIC) was effectively re-used five times.
Glassner, Hanoch; Zchori-Fein, Einat; Compant, Stéphane; Sessitsch, Angela; Katzir, Nurit; Portnoy, Vitaly; Yaron, Sima
Endophytes are microorganisms that mainly colonize vegetative parts, but are also found in reproductive and disseminating organs, and may have beneficial characteristics. To identify microorganisms associated with the agriculturally important family, Cucurbitaceae, endophytes were initially determined in fruits of Cucumis melo Reticulatus Group 'Dulce' by a cultivation-independent approach based on fluorescence in situ hybridization using double labeling of oligonucleotide probes. Alpha-, Beta-, Gammaproteobacteria, Firmicutes and Actinobacteria were localized inside the fruits. Culturable bacteria were further isolated and identified from fruit tissues of 'Dulce', from fruits of other cultivated and wild-field-grown Cucurbitaceae, and from wild fruits growing under natural conditions. Low densities of culturable bacteria were detected in the investigated fruits, especially in four out of the five wild species, regardless of their growing environment. Substantial differences were observed between the wild and cultivated cucurbit taxa in regard to the number of colonized fruits as well as the type of endophytes. Bacillus was the most dominant genus of endophytes colonizing fruits of Cucurbitaceae. The antagonistic effects of isolated endophytes were assessed against cucurbit disease agents in dual-culture assays. Several bacterial isolates exhibited antagonistic properties against the tested plant pathogens. The identified bacteria may be useful for protecting plants not only in the field, but also for post-harvest.
Varian, Bernard J; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M; Mirabal, Sheyla; Erdman, Susan E
Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny.
Shi, Lye Huey; Balakrishnan, Kunasundari; Thiagarajah, Kokila; Mohd Ismail, Nor Ismaliza; Yin, Ooi Shao
Probiotics are live microorganisms that can be found in fermented foods and cultured milk, and are widely used for the preparation of infant food. They are well-known as “health friendly bacteria”, which exhibit various health beneficial properties such as prevention of bowel diseases, improving the immune system, for lactose intolerance and intestinal microbial balance, exhibiting antihypercholesterolemic and antihypertensive effects, alleviation of postmenopausal disorders, and reducing traveller’s diarrhoea. Recent studies have also been focused on their uses in treating skin and oral diseases. In addition to that, modulation of the gut-brain by probiotics has been suggested as a novel therapeutic solution for anxiety and depression. Thus, this review discusses on the current probiotics-based products in Malaysia, criteria for selection of probiotics, and evidences obtained from past studies on how probiotics have been used in preventing intestinal disorders via improving the immune system, acting as an antihypercholesterolemic factor, improving oral and dermal health, and performing as anti-anxiety and anti-depressive agents. PMID:27688852
An overall decline in technical literacy within the American public has come at a time when technological advances are accelerating in the United States and around the world. This had led to a large communication gulf between the general public and the technologists. Nowhere is this more evident then with the topic of radiation. Regrettably, too few people know about sources of radiation, the pervasiveness, amounts, and variabilities, and do not have a true understanding of the environment in which we live. Nor do many people know that radiation has been used in beneficial ways for decades around the world. While the general public does not know of the scientific applications to which radiation has been deployed, it nevertheless had benefited tremendously from these efforts. Thanks to the well know properties of radiation, scientific ingenuity has found many uses of radiation in chemical and agricultural research, biomedical research, in the diagnoses and treatment of hundreds of types of diseases, in industrial applications, food irradiation, and many others. This paper provides a sample of the types of uses to which radiation has been used to help advance the betterment of humankind.
Martínez-Medina, Ainhoa; Fernández, Iván; Sánchez-Guzmán, María J; Jung, Sabine C; Pascual, Jose A; Pozo, María J
Root colonization by selected Trichoderma isolates can activate in the plant a systemic defense response that is effective against a broad-spectrum of plant pathogens. Diverse plant hormones play pivotal roles in the regulation of the defense signaling network that leads to the induction of systemic resistance triggered by beneficial organisms [induced systemic resistance (ISR)]. Among them, jasmonic acid (JA) and ethylene (ET) signaling pathways are generally essential for ISR. However, Trichoderma ISR (TISR) is believed to involve a wider variety of signaling routes, interconnected in a complex network of cross-communicating hormone pathways. Using tomato as a model, an integrative analysis of the main mechanisms involved in the systemic resistance induced by Trichoderma harzianum against the necrotrophic leaf pathogen Botrytis cinerea was performed. Root colonization by T. harzianum rendered the leaves more resistant to B. cinerea independently of major effects on plant nutrition. The analysis of disease development in shoots of tomato mutant lines impaired in the synthesis of the key defense-related hormones JA, ET, salicylic acid (SA), and abscisic acid (ABA), and the peptide prosystemin (PS) evidenced the requirement of intact JA, SA, and ABA signaling pathways for a functional TISR. Expression analysis of several hormone-related marker genes point to the role of priming for enhanced JA-dependent defense responses upon pathogen infection. Together, our results indicate that although TISR induced in tomato against necrotrophs is mainly based on boosted JA-dependent responses, the pathways regulated by the plant hormones SA- and ABA are also required for successful TISR development.
Full Text Available Root colonization by selected Trichoderma isolates can activate in the plant a systemic defence response that is effective against a broad spectrum of plant pathogens. Diverse plant hormones play pivotal roles in the regulation of the defence signalling network that leads to the induction of systemic resistance triggered by beneficial organisms (ISR. Among them, jasmonic acid (JA and ethylene (ET signalling pathways are generally essential for ISR. However, Trichoderma ISR (TISR is believed to involve a wider variety of signalling routes, interconnected in a complex network of cross-communicating hormone pathways. Using tomato as a model, an integrative analysis of the main mechanisms involved in the systemic resistance induced by Trichoderma harzianum against the necrotrophic leaf pathogen Botrytis cinerea was performed. Root colonization by T. harzianum rendered the leaves more resistant to B. cinerea independently of major effects on plant nutrition. The analysis of disease development in shoots of tomato mutant lines impaired in the synthesis of the key defence related hormones JA, ET, salicylic acid (SA and abscisic acid (ABA and the peptide prosystemin (PS evidenced the requirement of intact JA, SA and ABA signalling pathways for a functional TISR. Expression analysis of several hormone related marker genes point to the role of priming for enhanced JA-dependent defence responses upon pathogen infection. Together, our results indicate that although TISR induced in tomato against the necrotrophs is mainly based on boosted JA-dependent responses, the pathways regulated by the plant hormones SA- and ABA are also required for successful TISR development
Weyens, Nele; van der Lelie, D.; Taghavi, S; Vangronsveld, Jaco
A promising field to exploit plant-endophyte partnerships is the remediation of contaminated soils and (ground) water. Many plant growth promoting endophytes can assist their host plant to overcome contaminant-induced stress responses, thus providing improved plant growth. During phytoremediation of organic contaminants, plants can further benefit from endophytes possessing appropriate degradation pathways and metabolic capabilities, leading to more efficient contaminant degradation and reduc...
Full Text Available Application of hyperaccumulator–endophyte symbiotic systems is a potential approach to improve phytoremediation efficiency, since some beneficial endophytic bacteria are able to detoxify heavy metals, alter metal solubility in soil and facilitate plant growth. The objective of this study was to isolate multi-metal resistant and plant beneficial endophytic bacteria and to evaluate their role in enhancing plant growth and metal accumulation/translocation. The metal resistant endophytic bacterial strain E6S was isolated from stems of the Zn/Cd hyperaccumulator plant Sedum plumbizincicola growing in metalliferous mine soils using Dworkin and Foster salts minimal agar medium with 1-aminocyclopropane-1-carboxylate (ACC as the sole nitrogen source, and identified as homologous to Achromobacter piechaudii based on morphological and biochemical characteristics, partial 16S rDNA sequence and phylogenetic analysis. Strain E6S showed high level of resistance to various metals (Cd, Zn and Pb. Besides utilizing ACC, strain E6S exhibited plant beneficial traits, such as solubilization of phosphate and production of indole-3-acetic acid. Inoculation with E6S significantly increased the bioavailability of Cd, Zn and Pb in soil. In addition, bacterial cells bound considerable amounts of metal ions in the following order: Zn ˃ Cd ˃ Pb. Inoculation of E6S significantly stimulated plant biomass, uptake and bioaccumulation of Cd, Zn and Pb. However, E6S greatly reduced the root to shoot translocation of Cd and Zn, indicating that bacterial inoculation assisted the host plant to uptake and store heavy metals in its root system. Inoculation with the endophytic bacterium E6S homologous to A. piechaudii can improve phytostabilization of metalliferous soils due to its effective ability to enhance in situ metal rhizoaccumulation in plants.
Ma, Ying; Zhang, Chang; Oliveira, Rui S.; Freitas, Helena; Luo, Yongming
Application of hyperaccumulator-endophyte symbiotic systems is a potential approach to improve phytoremediation efficiency, since some beneficial endophytic bacteria are able to detoxify heavy metals, alter metal solubility in soil, and facilitate plant growth. The objective of this study was to isolate multi-metal resistant and plant beneficial endophytic bacteria and to evaluate their role in enhancing plant growth and metal accumulation/translocation. The metal resistant endophytic bacterial strain E6S was isolated from stems of the Zn/Cd hyperaccumulator plant Sedum plumbizincicola growing in metalliferous mine soils using Dworkin and Foster salts minimal agar medium with 1-aminocyclopropane-1-carboxylate (ACC) as the sole nitrogen source, and identified as homologous to Achromobacter piechaudii based on morphological and biochemical characteristics, partial 16S rDNA sequence and phylogenetic analysis. Strain E6S showed high level of resistance to various metals (Cd, Zn, and Pb). Besides utilizing ACC, strain E6S exhibited plant beneficial traits, such as solubilization of phosphate and production of indole-3-acetic acid. Inoculation with E6S significantly increased the bioavailability of Cd, Zn, and Pb in soil. In addition, bacterial cells bound considerable amounts of metal ions in the following order: Zn > Cd >Pb. Inoculation of E6S significantly stimulated plant biomass, uptake and bioaccumulation of Cd, Zn, and Pb. However, E6S greatly reduced the root to shoot translocation of Cd and Zn, indicating that bacterial inoculation assisted the host plant to uptake and store heavy metals in its root system. Inoculation with the endophytic bacterium E6S homologous to A. piechaudii can improve phytostabilization of metalliferous soils due to its effective ability to enhance in situ metal rhizoaccumulation in plants. PMID:26870079
Abdelrahman, Mostafa; Abdel-Motaal, Fatma; El-Sayed, Magdi; Jogaiah, Sudisha; Shigyo, Masayoshi; Ito, Shin-ichi; Tran, Lam-Son Phan
Trichoderma spp. are versatile opportunistic plant symbionts that can cause substantial changes in the metabolism of host plants, thereby increasing plant growth and activating plant defense to various diseases. Target metabolite profiling approach was selected to demonstrate that Trichoderma longibrachiatum isolated from desert soil can confer beneficial agronomic traits to onion and induce defense mechanism against Fusarium oxysporum f. sp. cepa (FOC), through triggering a number of primary and secondary metabolite pathways. Onion seeds primed with Trichoderma T1 strain displayed early seedling emergence and enhanced growth compared with Trichoderma T2-treatment and untreated control. Therefore, T1 was selected for further investigations under greenhouse conditions, which revealed remarkable improvement in the onion bulb growth parameters and resistance against FOC. The metabolite platform of T1-primed onion (T1) and T1-primed onion challenged with FOC (T1+FOC) displayed significant accumulation of 25 abiotic and biotic stress-responsive metabolites, representing carbohydrate, phenylpropanoid and sulfur assimilation metabolic pathways. In addition, T1- and T1+FOC-treated onion plants showed discrete antioxidant capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) compared with control. Our findings demonstrated the contribution of T. longibrachiatum to the accumulation of key metabolites, which subsequently leads to the improvement of onion growth, as well as its resistance to oxidative stress and FOC.
Febrilia Nur ‘Aini
Full Text Available Colletotrichum gloeosporioides is a disease which can cause significant yield loss of cocoa. The objective of this research is to investigate the abilityof antagonist microbes, Trichoderma harzianum, Trichoderma koningii, Bacillus subtilis and Pseudomonas fluorescens in controlling gloeosporioides biologically in laboratorium condition. The experiment was carried out in Crop Protection Laboratory, Indonesian Coffee and Cocoa Research Institute. Results of this research showed that antagonist fungi, T. harzianum, T. koningii, had a stronger ability in inhibiting growth of C. gloeosporioides about 83% compared to the ability of antagonist bacteria, B. subtilis and P. fluorescens, only about 49%. Key words: Growth inhibition, Colletotrichum gloeosporioides, Trichoderma harzianum, Trichoderma koningii, Bacillus subtilis, Pseudomonas fluorescens.
Thrane, Ulf; Poulsen, S.B.; Nirenberg, H.I.
Forty-four Trichoderma strains from water-damaged building materials or indoor dust were classified with chromatographic image analysis on full chromatographic matrices obtained by high performance liquid chromatography with UV detection of culture extracts. The classes were compared...
Strobel, Gary; Singh, Sanjay K; Riyaz-Ul-Hassan, Syed; Mitchell, Angela M; Geary, Brad; Sears, Joe
A Phoma sp. was isolated and characterized as endophytic and as a pathogen of Larrea tridentata (creosote bush) growing in the desert region of southern Utah, USA. This fungus produces a unique mixture of volatile organic compounds (VOCs), including a series of sesquiterpenoids, some alcohols and several reduced naphthalene derivatives. Trans-caryophyllene, a product in the fungal VOCs, was also noted in the VOCs of this pungent plant. The gases of Phoma sp. possess antifungal properties and is markedly similar to that of a methanolic extract of the host plant. Some of the test organisms with the greatest sensitivity to the Phoma sp. VOCs were Verticillium, Ceratocystis, Cercospora and Sclerotinia while those being the least sensitive were Trichoderma, Colletotrichum and Aspergillus. We discuss the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship with implications for utilization as an energy source.
Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.
Jeerapong, Chotika; Phupong, Worrapong; Bangrak, Phuwadol; Intana, Warin; Tuchinda, Patoomratana
A new decalin derivative, trichoharzianol (1), together with three known compounds, eujavanicol A (2), 5-hydroxy-3-hydroxymethyl-2-methyl-7-methoxychromone (3), and 4,6-dihydroxy-5-methylphthalide (4), were isolated from Trichoderma harzianum F031. For the first time, compounds 2-4 were reported from the Trichoderma species. Their structures were characterized by spectroscopic methods. Trichoharzianol (1) showed the highest antifungal activity against Colletotrichum gloeosporioides, with a minimum inhibitory concentration (MIC) of 128 μg/mL.
Vega, Fernando E; Pava-Ripoll, Monica; Posada, Francisco; Buyer, Jeffrey S
Eighty-seven culturable endophytic bacterial isolates in 19 genera were obtained from coffee plants collected in Colombia (n = 67), Hawaii (n = 17), and Mexico (n = 3). Both Gram positive and Gram negative bacteria were isolated, with a greater percentage (68%) being Gram negative. Tissues yielding bacterial endophytes included adult plant leaves, various parts of the berry (e.g., crown, pulp, peduncle and seed), and leaves, stems, and roots of seedlings. Some of the bacteria also occurred as epiphytes. The highest number of bacteria among the berry tissues sampled was isolated from the seed, and includes Bacillus , Burkholderia , Clavibacter , Curtobacterium , Escherichia , Micrococcus , Pantoea , Pseudomonas , Serratia , and Stenotrophomonas . This is the first survey of the endophytic bacteria diversity in various coffee tissues, and the first study reporting endophytic bacteria in coffee seeds. The possible role for these bacteria in the biology of the coffee plant remains unknown.
Schardl, Christopher L; Leuchtmann, Adrian; Spiering, Martin J
Grasses (family Poaceae) and fungi of the family Clavicipitaceae have a long history of symbiosis ranging in a continuum from mutualisms to antagonisms. This continuum is particularly evident among symbioses involving the fungal genus Epichloe (asexual forms = Neotyphodium spp.). In the more mutualistic symbiota, the epichloe endophytes are vertically transmitted via host seeds, and in the more antagonistic symbiota they spread contagiously and suppress host seed set. The endophytes gain shelter, nutrition, and dissemination via host propagules, and can contribute an array of host fitness enhancements including protection against insect and vertebrate herbivores and root nematodes, enhancements of drought tolerance and nutrient status, and improved growth particularly of the root. In some systems, such as the tall fescue N. coenophialum symbioses, the plant may depend on the endophyte under many natural conditions. Recent advances in endophyte molecular biology promise to shed light on the mechanisms of the symbioses and host benefits.
Martha E Trujillo
Full Text Available Endophytic microorganisms live inside plants for at least part of their life cycle. According to their life strategies, bacterial endophytes can be classified as "obligate" or "facultative". Reports that members of the genus Micromonospora, Gram-positive Actinobacteria, are normal occupants of nitrogen-fixing nodules has opened up a question as to what is the ecological role of these bacteria in interactions with nitrogen-fixing plants and whether it is in a process of adaptation from a terrestrial to a facultative endophytic life. The aim of this work was to analyse the genome sequence of Micromonospora lupini Lupac 08 isolated from a nitrogen fixing nodule of the legume Lupinus angustifolius and to identify genomic traits that provide information on this new plant-microbe interaction. The genome of M. lupini contains a diverse array of genes that may help its survival in soil or in plant tissues, while the high number of putative plant degrading enzyme genes identified is quite surprising since this bacterium is not considered a plant-pathogen. Functionality of several of these genes was demonstrated in vitro, showing that Lupac 08 degraded carboxymethylcellulose, starch and xylan. In addition, the production of chitinases detected in vitro, indicates that strain Lupac 08 may also confer protection to the plant. Micromonospora species appears as new candidates in plant-microbe interactions with an important potential in agriculture and biotechnology. The current data strongly suggests that a beneficial effect is produced on the host-plant.
Trujillo, Martha E; Bacigalupe, Rodrigo; Pujic, Petar; Igarashi, Yasuhiro; Benito, Patricia; Riesco, Raúl; Médigue, Claudine; Normand, Philippe
Endophytic microorganisms live inside plants for at least part of their life cycle. According to their life strategies, bacterial endophytes can be classified as "obligate" or "facultative". Reports that members of the genus Micromonospora, Gram-positive Actinobacteria, are normal occupants of nitrogen-fixing nodules has opened up a question as to what is the ecological role of these bacteria in interactions with nitrogen-fixing plants and whether it is in a process of adaptation from a terrestrial to a facultative endophytic life. The aim of this work was to analyse the genome sequence of Micromonospora lupini Lupac 08 isolated from a nitrogen fixing nodule of the legume Lupinus angustifolius and to identify genomic traits that provide information on this new plant-microbe interaction. The genome of M. lupini contains a diverse array of genes that may help its survival in soil or in plant tissues, while the high number of putative plant degrading enzyme genes identified is quite surprising since this bacterium is not considered a plant-pathogen. Functionality of several of these genes was demonstrated in vitro, showing that Lupac 08 degraded carboxymethylcellulose, starch and xylan. In addition, the production of chitinases detected in vitro, indicates that strain Lupac 08 may also confer protection to the plant. Micromonospora species appears as new candidates in plant-microbe interactions with an important potential in agriculture and biotechnology. The current data strongly suggests that a beneficial effect is produced on the host-plant.
Locoweeds contain the toxic indolizidine alkaloid swainsonine, which is produced by the endophytic fungi Undifilum species. Previously we reported that swainsonine concentrations differ between populations of Oxytropis sericea. We hypothesized that the genotype of the plant, endophyte, or an inter...
Card, Stuart; Johnson, Linda; Teasdale, Suliana; Caradus, John
Endophytes associate with the majority of plant species found in natural and managed ecosystems. They are regarded as extremely important plant partners that provide improved stress tolerance to the host compared with plants that lack this symbiosis. Fossil records of endophytes date back more than 400 million years, implicating these microorganisms in host plant adaptation to habitat transitions. However, it is only recently that endophytes, and their bioactive products, have received meaningful attention from the scientific community. The benefits some endophytes can confer on their hosts include plant growth promotion and survival through the inhibition of pathogenic microorganisms and invertebrate pests, the removal of soil contaminants, improved tolerance of low fertility soils, and increased tolerance of extreme temperatures and low water availability. Endophytes are extremely diverse and can exhibit many different biological behaviours. Not all endophyte technologies have been successfully commercialised. Of interest in the development of the next generation of plant protection products is how much of this is due to the biology of the particular endophytic microorganism. In this review, we highlight selected case studies of endophytes and discuss their lifestyles and behavioural traits, and discuss how these factors contribute towards their effectiveness as biological control agents.
Full Text Available O uso de microrganismos é uma alternativa para o controle de doenças em plantas. Todavia, é prudente verificar a interação desse com os demais métodos de controle empregados em determinada cultura. Dessa forma, objetivou-se avaliar a fungitoxicidade dos herbicidas sobre o crescimento e desenvolvimento dos isolados de Trichoderma spp. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 6 x 6 x 4, com quatro repetições. O fator A correspondeu aos herbicidas pendimethalin, clomazone, carfentrazone-ethyl, oxadiazon, thiobencarb + propanil e byspiribac-sodium; o fator B, às doses dos herbicidas - 0, 25, 50, 75, 100 e 200% da dose recomendada; e o fator C, aos isolados de Trichoderma spp. AJAM 18, CE 66, TRI 01 e TRI 02. O ensaio foi realizado em condições in vitro; avaliaram-se o crescimento micelial radial (CMR e a esporulação dos isolados após aplicação dos herbicidas. Observaram-se diferenças de sensibilidade dos isolados para o mesmo produto testado. O oxadiazon reduziu o CMR dos isolados AJAM 18 e TRI 01 em 66 e 35%, respectivamente. No entanto, reduziu apenas 16% do CMR do isolado TRI 02 e não alterou o CMR do isolado CE 66 mesmo em 200% da dose recomendada. Verificaram-se diferentes efeitos dos produtos em cada isolado. A mistura comercial de thiobencarb+propanil foi altamente tóxica aos isolados de Trichoderma spp., com reduções em torno de 85% no CMR e no número de esporos. Por outro lado, o byspiribac-sodium pouco afetou os isolados, apresentando reduções inferiores a 10% no CMR e na esporulação. O carfentrazone-ethyl e byspiribac-sodium demonstraram ser compatíveis com os isolados de Trichoderma spp. estudados.The use of microorganisms is an alternative for the control of plant diseases. However, one should verify its interaction with other methods of control used for a particular crop. The objective of this work was to evaluate the effect of herbicide fungitoxicity on the growth and
@@ From over 800 fungal strains of Trichoderma Spp. , 6 strains were found to greatly inhibit the growing of Rhizocotonia solani, the pathogen of rice sheath blight in dual culture. Among them, strain T3 was the best antagonist,which reduced the growing of the pathogen by 52.54% (Table 1). In field, both the pesticide Jinggangmycin and the mixture of T1 T6 could reduce the severity of rice sheath blight(Table 2), which resulted in the increases of seed setting rate and 1000 grain weight. Because the effect of the antagonists on the control of the pathogen could be partially realized in the watery environment, studies on the biocontrol mechanism of the fungi should be strengthened to help the establishment of a best way of antagonist utilization.
Full Text Available The title compound, C20H28O3, known as `trichodermaerin' [systematic name: (4E-4,9,15,16,16-pentamethyl-6-oxatetracyclo[10.3.1.01,10.05,9]hexadec-4-ene-7,13-dione], is a diterpene lactone which was isolated from Trichoderma asperellum. The structure has a tetracycic 6–5–7–5 ring system, with the cyclohexanone ring adopting a twisted half-chair conformation and the cyclopentane ring adopting a half-chair conformation, whereas the cycloheptene and tetrahydrofurananone rings are in chair and envelope (with the methyl-substituted C atom as the flap conformations, respectively. The three-dimensional architecture is stabilized by C—H...O interactions.
Chantrapromma, Suchada; Jeerapong, Chotika; Phupong, Worrapong; Quah, Ching Kheng; Fun, Hoong-Kun
The title compound, C20H28O3, known as ‘trichodermaerin’ [systematic name: (4E)-4,9,15,16,16-pentamethyl-6-oxatetracyclo[10.3.1.01,10.05,9]hexadec-4-ene-7,13-dione], is a diterpene lactone which was isolated from Trichoderma asperellum. The structure has a tetracycic 6–5–7–5 ring system, with the cyclohexanone ring adopting a twisted half-chair conformation and the cyclopentane ring adopting a half-chair conformation, whereas the cycloheptene and tetrahydrofurananone rings are in chair and envelope (with the methyl-substituted C atom as the flap) conformations, respectively. The three-dimensional architecture is stabilized by C—H⋯O interactions. PMID:24826124
Beltran-Garcia, Miguel J.; White, JR; Prado, Fernanda M; Prieto, Katia R.; Yamaguchi, Lydia F.; Torres, Monica S.; Kato, Massuo J.; Medeiros, Marisa H. G.; Di Mascio,Paolo
Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from 15N-labe...
El-Gendy, Mervat Morsy Abbas Ahmed; Al-Zahrani, Salha Hassan Mastour; El-Bondkly, Ahmed Mohamed Ahmed
Among all fungal endophytes isolates derived from different ethno-medical plants, the hyper-yield L-asparaginase and L-glutaminase wild strains Trichoderma sp. Gen 9 and Cladosporium sp. Gen 20 using rice straw under solid-state fermentation (SSF) were selected. The selected strains were used as parents for the intergeneric protoplast fusion program to construct recombinant strain for prompt improvement production of these enzymes in one recombinant strain. Among 21 fusants obtained, the recombinant strain AYA 20-1, with 2.11-fold and 2.58-fold increase in L-asparaginase and L-glutaminase activities more than the parental isolates Trichoderma sp. Gen 9 and Cladosporium sp. Gen 20, respectively, was achieved using rice straw under SSF. Both therapeutic enzymes L-asparaginase and L-glutaminase were purified and characterized from the culture supernatant of the recombinant AYA 20-1 strain with molecular weights of 50.6 and 83.2 kDa, respectively. Both enzymes were not metalloenzymes. Whereas thiol group blocking reagents such as p-chloromercurybenzoate and iodoacetamide totally inhibited L-asparaginase activity, which refer to sulfhydryl groups and cysteine residues involved in its catalytic activity, they have no effect toward L-glutaminase activity. Interestingly, potent anticancer, antioxidant, and antimicrobial activities were detected for both enzymes.
Saha, C; Mukherjee, G; Agarwal-Banka, P; Seal, A
Endophytic microbes isolated from plants growing in nutrient-deficient environments often possess properties that improve nutrition of agriculturally important plants. A consortium of non-rhizobial endophytic microbes isolated from a macrophyte Typha angustifolia growing in the marginal wetlands associated with a Uranium mine was characterized for their beneficial effect on rice and the mechanisms of growth promotion were investigated. The microbes were identified and characterized for their potential plant growth promoting (PGP) properties. Effect of these microbes on nitrogen (N)-metabolism of rice was tested as Typha endophytes were predominantly (N)-fixing. Relative N-use efficiency and expression of genes involved in N-uptake and assimilation were investigated in treated plants. Evidence of horizontal gene transfer (HGT) of dinitrogen reductase gene was observed within the consortium from a Pseudomonas stutzeri strain. The consortium behaved as plant probiotic and showed substantial growth benefits to Typha, their natural host as well as to rice. Typha endophytes colonized rice endosphere significantly increasing biomass, shoot length and chlorophyll content in rice plants both under N-sufficient and N-deficient conditions. N-uptake and assimilation genes were upregulated in plants treated with the endophytes even after three weeks post infection. Our results suggested, HGT of nitrogen-fixation trait to be highly prevalent among endophytes isolated from nutrient-poor habitats of the uranium mine. A long-term nitrogen deficiency response in the treated plants was elicited by the consortium improving N-uptake, assimilation and relative N-use efficiency of rice plants. This appeared to be at least one of the main strategies of plant growth promotion.
Full Text Available Microbes living symbiotically in plant tissues mutually cooperate with each other by providing nutrients for proliferation of the partner organism and have a beneficial effect on plant growth. However, few studies thus far have examined the interactive effect of endophytic bacteria and arbuscular mycorrhizal fungi (AMF in hostile conditions and their potential to improve plant stress tolerance. In this study, we investigated how the synergistic interactions of endophytic bacteria and AMF affect plant growth, nodulation, nutrient acquisition and stress tolerance of Acacia gerrardii under salt stress. Plant growth varied between the treatments with both single inoculants and was higher in plants inoculated with the endophytic B. subtilis strain than with AMF. Co-inoculated A. gerrardii had a significantly greater shoot and root dry weight, nodule number, and leghemoglobin content than those inoculated with AMF or B. subtilis alone under salt stress. The endophytic B. subtilis could alleviate the adverse effect of salt on AMF colonization. The differences in nitrate and nitrite reductase and nitrogenase activities between uninoculated plants and those inoculated with AMF and B. subtilis together under stress were significant. Both inoculation treatments, either B. subtilis alone or combined with AMF, enhanced the N, P, K, Mg and Ca contents and phosphatase activities in salt-stressed A. gerrardii tissues and reduced Na and Cl concentration, thereby protecting salt-stressed plants from ionic and osmotic stress-induced changes. In conclusion, our results indicate that endophytic bacteria and AMF contribute to a tripartite mutualistic symbiosis in A. gerrardii and are coordinately involved in the plant adaptation to salt stress tolerance.Key words: AMF, endophyte, Acacia gerrardii, salinity, nutrition
d'Aquino L; Carboni M; Woo S L; Morgana M; Nardi L; Lorito M
@@ Rare earth elements (REEs) enriched fertilisers are currently used in China for soil and foliar applications to crops, but little is known about the effect of REEs applications on the growth of beneficial and detrimental soilborne microorganisms. The growth of biological control agents Trichoderma atroviride strain P1, Trichoderma harzianum strain A6 and strain T22, plant pathogens Botrytis cinerea, Alternaria alternata, Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum was investigated in the presence of REEs. An in vitro assays was used to monitor the effect of different concentration levels of either a mix of REEs (La, Ce, Pr, Nd) nitrates or lanthanum alone in comparison to treatments conducted with potassium nitrate and water. Although all fungi were affected when the REEs mix or lanthanum were present at concentrations higher than 100 mM, the growth inhibition depended mainly upon the combination of compounds, the dose and the fungal species or strains tested. Trichoderma strains and B. cinerea were more sensitive than A.alternata, F. solani, R. solani or at higher concentrations. Differing growth responses of some fungi to treatments with REEs mix vs. lanthanum alone indicated that in given situations the effect of the REEs compounds may be caused by elements other than lanthanum or by element mixtures.Further investigations are in progress to determine the effect of REEs on important interactions in the soil community between beneficial fungi, pathogenic fungi and/or the plant. REEs are naturally present in the environment and in biological systems but accumulation in soil can take place following successive applications. Therefore, it would be useful to achieve a better understanding of the effect of REEs accumulation on the activity of rhizosphere microorganisms given the widespread use in some regions of rare earths as fertilizers and their presence as fertilizer contaminants.
邓毅; 王艳; 丁仁伟; 杨志军; 张艳萍
目的:通过对甘肃乌拉尔甘草野生与栽培品内生菌的分离,对甘草同属不同品种内生菌的优势菌种进行初步鉴定,比较二者的生理活性差异.方法:采用NA、PDA培养基对甘草野生与栽培品内生菌进行分离和纯化,并以分离频率比较判断各自优势菌种.结果:野生甘草分离到内生细菌65 株,内生真菌7 株,优势菌种为青霉菌属和曲霉属;栽培甘草分离到内生细菌54 株,内生真菌6 株,优势菌种为青霉菌属;野生与栽培甘草的内生真菌分属于6 个属,相同的有5 个属,不同的2个属为丝核菌属和木霉属.结论:野生与栽培甘草具有相趋同数量和种类的内生细菌与内生真菌,但二者内生真菌的菌属及优势菌种存在明显差异.%Objective: To compare the differences of biological activity between wild and cultivated glycyrrhiza uralensis through the isolation of endophytes and identification on dominant bacteria from endophytes of different species in the same genera. Method: Endophytes from wild and cultivated GanCao were isolated and purified with NA and PDA base. The dominant bacteria were compared and judged with frequency separation. Result: All 65 strains of endophytic bacteria and seven strains of endophytic fungi were isolated from wild GanCao, the dominant bacteria were penicillium spp and monillales; 54 strains of endophytic bacteria and six strains of endophytic fungi were isolated from cultivated GanCao, the dominant bacteria were penicillium spp; endophytic fungi isolated from wild and cultivated GanCao were in the six genera, there were five same genera, two different genera were rhi-zoctonia and trichoderma. Conclusion: Wild and cultivated GanCao have almost the same amount and kinds of endophytic bacteria and fungi, but there exists remarkable difference in genera and dominant bacteria of endophtic fungi in both.
HUANG Caihong; YANG Qian
Trichoderma spp. is a filamentous soil fungus known as an effective biocontrol agent of a range of important airborne and soilborne pathogens, it has universal distribution and economic importance. This article reviewed the researches on biocontrol mechanism for plant diseases and application of Trichoderma spp., especially Trichoderma harzianum in recent years.
Otieno, W.; Jeger, M.J.; Termorshuizen, A.J.
Six isolates of Trichoderma were screened for antagonism to Armillaria in tea stem sections buried in the soil. The inability of Armillaria to invade Trichoderma-colonized stem sections and the reduction of its viability in the plant materials following invasion of these by Trichoderma were used as
Lacy, Curt; Anderson, John D.; Andrae, John
Empirical animal performance data is used in evaluating the decision to convert toxic endophyte fescue to novel endophyte fescue. Results indicate that producers at three risk aversion levels prefer replacing their existing toxic fescue stands when the expected stand life for novel endophyte fescue is more than five years.
Zhu, Z X; Zhuang, W Y
Collections of Trichoderma having hyaline ascospores from different areas of China were examined. Using combined analyses of morphological data, culture characters and phylogenetic information based on rDNA sequences of partial nuc translation elongation factor 1-α encoding gene (TEF1-α) and the gene encoding the second largest nuc RNA polymerase subunit (RPB2), three new species, Trichoderma applanatum, T. oligosporum and T. sinoluteum, were discovered and are described. Trichoderma applanatum produces continuous flat to pulvinate, white to cream stromata with dense orange or pale brown ostioles, and simple acremonium-like to verticillium-like conidiophores, belongs to the Hypocreanum clade and is closely related to T. decipiens. Trichoderma oligosporum forms reddish brown stromata with a downy surface, hyaline conidia and gliocladium-like conidiophores, and is closely related to but distinct from T. crystalligenum in the Psychrophila clade. Trichoderma sinoluteum, as a member of the Polysporum clade, is characterized by pale yellow stromata, white pustulate conidiomata, pachybasium-like conidiophores, and hyaline conidia. Differences between the new species and their close relatives are discussed.
魏宝阳; 曹亮; 李顺祥; 黄丹; 周晋; 虢小翊
内生菌与其宿主药用植物在长期协同进化过程中形成了互惠共生关系.在介绍内生菌与药用植物有效成分积累的关系及内生菌对药用植物次生代谢产物影响机制的基础上,探讨了内生菌对药用植物生长、抗逆性、道地性的影响,提出了当前药用植物内生菌研究中存在的问题与对策.%Endophyte and its host medicinal plants formed a mutually beneficial symbiotic relationship in the long-term co-evolution process. This paper reviewed the relationship between endophyte and the accumulation of active ingredients, and the effect mechanism of endophyte to secondary metabolites in medicinal plants. The principle of endophyte to the growth, stress resistance and genuineness of medicinal plants were discussed. The main problems and countermeasures were provided too.
Yao, Xiang; Christensen, Michael J; Bao, Gensheng; Zhang, Chunping; Li, Xiuzhang; Li, Chunjie; Nan, Zhibiao
Overgrazing of China's grasslands is increasingly causing biodiversity to decline. In degenerated grasslands of northwest China endophyte (Epichloё gansuensis) infected Achnatherum inebrians (drunken horse grass) is becoming widely distributed because of its toxicity to livestock. In this study, we investigated the ecological consequences of endophyte toxicity in this native grass, at three sites in northwest China, by comparing seed production of plant species and arthropod abundance in overgrazed grasslands with and without the presence of A. inebrians. Our findings demonstrate that the presence of endophyte infected A. inebrians reduces the loss of plant and arthropod biodiversity by providing a protected nursery free of animal grazing. Therefore, A. inebrians, typically regarded as an unwanted toxic invader by pastoralists, should be viewed as beneficial for grasslands as its presence maintains plant and arthropod biodiversity, and provides a foundation stone in the reconstruction and restoration of these grassland ecosystems.
Kamala, Thongram; Devi, Sarangthem Indira; Thingnam, Gourshyam; Somkuwar, Bharat Gopalrao
We investigated the occurrence and genetic diversity of Trichoderma and Hypocrea in Manipur which lies in the Indo-Burma biodiversity hot spot region. 65 Trichoderma isolates were identified at species level by morphological as well as sequence based analysis of the internal transcribed spacer region 1 and 4. Altogether 22 different species of Trichoderma and Hypocrea were found, of which Trichoderma harzianum represent the dominant species. Phylogenetic analysis reveals a clear cut distinction of strains isolated from various collection sites which further hints the need for detail study of Trichoderma on molecular level.
张广志; 杨合同; 张新建; 李纪顺; 陈凯; 黄玉杰
[Objective] Identification of two Trichoderma isolates were isolated from the soil in vegetable greenhouses and the pileus of Asafoetida mushroom. [Methods] By combination of morphological charaters and application of internal transcribed spacer (ITS). [Results] Two Trichoderma isolates were identified as Trichoderma pleuroticola S.H.Yu & Park sp. nov. and Trichoderma pleurotum S.H.Yu & Park. The morphological charaters of T. pleuroticola is similar with T. harzianum, but its conidiospore is obviously more than T. harzianum, secretes dark brown pigment, and forms yellow crystal on PDA medium. The typical characteristics of Trichoderma pleurotum is that its conidiophores are mostly solitary and more or less prostrate, branches scattered, arising separately and bearing crowded whorls of appressed phialides at the apex rsembling the conidiophore in Gliocladium. [Conclusion] Two Trichoderma isolates are T. pleuroticola and T. pleurotum respectively, which are two new record species in China.%[目的]对蔬菜大棚土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌进行分类鉴定.[方法]结合形态学分类特征和ITS序列分析的方法进行鉴定.[结果]从蔬菜大棚的土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌分别为Trichoderma pleuroticola和T.pleurotum.T.pleuroticola的形态特征与T.harzianum相似,但其分生孢子显著大于T.harzianum的分生孢子,且在PDA上产生黑褐色的色素以及黄色的结晶物.T.pleurotum 典型特征是分生孢子梗单生,有时匍匐,分枝散生,初级分枝和分生孢子梗顶端聚生,类似粘帚霉.[结论]分离的两株木霉分别是T.pleuroticola和T.pleurotum,为木霉菌中国新纪录种.
Elissandro Fonseca dos Banhos
Full Text Available Beneficial interactions between plants and microorganisms have been investigated under different ecological, physiological, biochemical, and genetic aspects. However, the systematic exploration of biomolecules with potential for biotechnological products from this interaction still is relatively scarce. Therefore, this study aimed the evaluation of the diversity and antimicrobial activity of the endophytic fungi obtained from roots, stems and leafs of Myrcia guianensis (Myrtaceae from the Brazilian Amazon. 156 endophytic fungi were isolated and above 80% were identified by morphological examination as belonging to the genera Pestalotiopsis, Phomopsis, Aspergillus, Xylaria, Nectria, Penicillium and Fusarium. Fermented broth of those fungi were assayed for antimicrobial activity and four inhibited the growth of Staphylococcus aureus, Enterococcus faecalis, Candida albicans and Penicillium avellaneum. As the strain named MgRe2.2.3B (Nectria haematococca had shown the most promising results against those pathogenic strains, its fermented broth was fractioned and only its two low polar fractions demonstrated to be active. Both fractions exhibited a minimum bactericidal concentration of 50 µg.mL-1 against S. aureus and a minimum fungicidal concentration of 100 µg.mL-1 against P. avellaneum. These results demonstrate the diversity of fungal genera in M. guianensis and the potential of these endophytic fungi for the production of new antibiotics.
Dos Banhos, Elissandro Fonseca; de Souza, Antonia Queiroz Lima; de Andrade, Juliano Camurça; de Souza, Afonso Duarte Leão; Koolen, Hector Henrique Ferreira; Albuquerque, Patrícia Melchionna
Beneficial interactions between plants and microorganisms have been investigated under different ecological, physiological, biochemical, and genetic aspects. However, the systematic exploration of biomolecules with potential for biotechnological products from this interaction still is relatively scarce. Therefore, this study aimed the evaluation of the diversity and antimicrobial activity of the endophytic fungi obtained from roots, stems and leafs of Myrcia guianensis (Myrtaceae) from the Brazilian Amazon. 156 endophytic fungi were isolated and above 80% were identified by morphological examination as belonging to the genera Pestalotiopsis, Phomopsis, Aspergillus, Xylaria, Nectria, Penicillium and Fusarium. Fermented broth of those fungi were assayed for antimicrobial activity and four inhibited the growth of Staphylococcus aureus, Enterococcus faecalis, Candida albicans and Penicillium avellaneum. As the strain named MgRe2.2.3B (Nectria haematococca) had shown the most promising results against those pathogenic strains, its fermented broth was fractioned and only its two low polar fractions demonstrated to be active. Both fractions exhibited a minimum bactericidal concentration of 50 μg.mL(-1) against S. aureus and a minimum fungicidal concentration of 100 μg.mL(-1) against P. avellaneum. These results demonstrate the diversity of fungal genera in M. guianensis and the potential of these endophytic fungi for the production of new antibiotics.
Full Text Available Epichloë fungal endophytes are broadly found in cool-season grasses. The symbiosis between these grasses and Epichloë may improve the abiotic and biotic resistance of the grass plant, but some Epichloë species produce alkaloids that are toxic for livestock. Therefore, it is important to understand the characteristics of the grass-Epichloë s symbiosis so that the beneficial aspects can be preserved and the toxic effects to livestock can be avoided. Since the 1990s, Chinese researchers have conducted a series of studies on grass-Epichloë symbiosis. In this review, we describe the current state of Epichloë endophyte research in Chinese native grasses. We found that more than 77 species of native grasses in China are associated with Epichloë endophytes. In addition, we review the effects of various Epichloë species on native grass responses to abiotic and biotic stress, phylogeny, and alkaloid production. We provide an overview of the study of Epichloë species on native grasses in China and directions for future research.
Song, Hui; Nan, Zhibiao; Song, Qiuyan; Xia, Chao; Li, Xiuzhang; Yao, Xiang; Xu, Wenbo; Kuang, Yu; Tian, Pei; Zhang, Qingping
Epichloë fungal endophytes are broadly found in cool-season grasses. The symbiosis between these grasses and Epichloë may improve the abiotic and biotic resistance of the grass plant, but some Epichloë species produce alkaloids that are toxic for livestock. Therefore, it is important to understand the characteristics of the grass-Epichloë s symbiosis so that the beneficial aspects can be preserved and the toxic effects to livestock can be avoided. Since the 1990s, Chinese researchers have conducted a series of studies on grass-Epichloë symbiosis. In this review, we describe the current state of Epichloë endophyte research in Chinese native grasses. We found that more than 77 species of native grasses in China are associated with Epichloë endophytes. In addition, we review the effects of various Epichloë species on native grass responses to abiotic and biotic stress, phylogeny, and alkaloid production. We provide an overview of the study of Epichloë species on native grasses in China and directions for future research.
Eevers, N; Gielen, M; Sánchez-López, A; Jaspers, S; White, J C; Vangronsveld, J; Weyens, N
Many endophytes have beneficial effects on plants and can be exploited in biotechnological applications. Studies hypothesize that only 0.001-1% of all plant-associated bacteria are cultivable. Moreover, even after successful isolations, many endophytic bacteria often show reduced regrowth capacity. This research aimed to optimize isolation processes and culturing these bacteria afterwards. We compared several minimal and complex media in a screening. Beside the media themselves, two gelling agents and adding plant extract to media were investigated to enhance the number and diversity of endophytes as well as the growth capacity when regrown after isolation. In this work, 869 medium delivered the highest numbers of cultivable bacteria, as well as the highest diversity. When comparing gelling agents, no differences were observed in the numbers of bacteria. Adding plant extract to the media lead to a slight increase in diversity. However, when adding plant extract to improve the regrowth capacity, sharp increases of viable bacteria occurred in both rich and minimal media.
Full Text Available This study provides new insights into the dynamics of bacterial community structure during phytoremediation. The communities of cultivable autochthonous endophytic bacteria in ryegrass exposed to polycyclic aromatic hydrocarbons (PAHs were investigated with regard to their potential to biodegrade PAHs. Bacterial counts and 16S rRNA gene sequence were used in the microbiological evaluation. A total of 33 endophytic bacterial strains were isolated from ryegrass plants, which represented 15 different genera and eight different classes, respectively. Moreover, PAH contamination modified the composition and structure of the endophytic bacterial community in the plants. Bacillus sp., Pantoea sp., Pseudomonas sp., Arthrobacter sp., Pedobacter sp. and Delftia sp. were only isolated from the seedlings exposed to PAHs. Furthermore, the dominant genera in roots shifted from Enterobacter sp. to Serratia sp., Bacillus sp., Pantoea sp., and Stenotrophomonas sp., which could highly biodegrade phenanthrene (PHE. However, the diversity of endophytic bacterial community was decreased by exposure to the mixture of PAHs, and increased by respective exposure to PHE and pyrene (PYR, while the abundance was increased by PAH exposure. The results clearly indicated that the exposure of plants to PAHs would be beneficial for improving the effectiveness of phytoremediation of PAHs.
Ekanayake, Piyumi N; Kaur, Jatinder; Tian, Pei; Rochfort, Simone J; Guthridge, Kathryn M; Sawbridge, Timothy I; Spangenberg, German C; Forster, John W
Symbiotic associations between tall fescue grasses and asexual Epichloë fungal endophytes exhibit biosynthesis of alkaloid compounds causing both beneficial and detrimental effects. Candidate novel endophytes with favourable chemotypic profiles have been identified in germplasm collections by screening for genetic diversity, followed by metabolite profile analysis in endogenous genetic backgrounds. A subset of candidates was subjected to genome survey sequencing to detect the presence or absence and structural status of known genes for biosynthesis of the major alkaloid classes. The capacity to produce specific metabolites was directly predictable from metabolic data. In addition, study of duplicated gene structure in heteroploid genomic constitutions provided further evidence for the origin of such endophytes. Selected strains were inoculated into meristem-derived callus cultures from specific tall fescue genotypes to perform isogenic comparisons of alkaloid profile in different host backgrounds, revealing evidence for host-specific quantitative control of metabolite production, consistent with previous studies. Certain strains were capable of both inoculation and formation of longer-term associations with a nonhost species, perennial ryegrass (Lolium perenne L.). Discovery and primary characterisation of novel endophytes by DNA analysis, followed by confirmatory metabolic studies, offers improvements of speed and efficiency and hence accelerated deployment in pasture grass improvement programs.
Aly, Amal Hassan; Debbab, Abdessamad; Proksch, Peter
Fungal endophytes residing in the internal tissues of living plants occur in almost every plant on earth from the arctic to the tropics. The endophyte-host relationship is described as a balanced symbiotic continuum ranging from mutualism through commensalism to parasitism. This overview will highlight selected aspects of endophyte diversity, host specificity, endophyte-host interaction and communication as well as regulation of secondary metabolite production with emphasis on advanced genomic methods and their role in improving our current knowledge of endophytic associations. Furthermore, the chemical potential of endophytic fungi for drug discovery will be discussed with focus on the detection of pharmaceutically valuable plant constituents as products of fungal biosynthesis. In addition, selected examples of bioactive metabolites reported in recent years (2008-2010) from fungal endophytes residing in terrestrial plants are presented grouped according to their reported biological activities.
Poholl Adan Sagratzki Cavero
Full Text Available Black Sigatoka disease caused by Mycosphaerella fijiensis is the most severe banana disease worldwide. The pathogen is in an invasive phase in Brazil and is already present in most States of the country. The potential of 29 isolates of Trichoderma spp. was studied for the control of black Sigatoka disease under field conditions. Four isolates were able to significantly reduce disease severity and were further tested in a second field experiment. Isolate 2.047 showed the best results in both field experiments and was selected for fungicide sensitivity tests and mass production. This isolate was identified as Trichoderma atroviride by sequencing fragments of the ITS region of the rDNA and tef-1α of the RNA polymerase. Trichoderma atroviride was as effective as the fungicide Azoxystrobin, which is recommended for controlling black Sigatoka. This biocontrol agent has potential to control the disease and may be scaled-up for field applications on rice-based solid fermentation
Strain T02-25 was selected from approximately 30 rhizosphere isolates of Trichoderma species isolated from roots of crops. Its biological activity against Rhizoctonia solani was determined for the control efficacy to pepper seedling blight caused by R. solani in the field. The assay methods were treating R. solani sclerotia by Trichoderma conidial suspension (106cfu ml-1) and scattering Thichoderma rice bran over the pepper root medium. The results showed that T02-25 was active against R. solani in both ways, and its control efficacy was 82.7% and 78.0%, respectively. In addition to comparison of the efficacy of the two application methods, the relationship of different factors in the control efficacy of Trichoderma against R. solani was discussed.
Park, Myung Soo; Oh, Seung-Yoon; Cho, Hae Jin; Fong, Jonathan J; Cheon, Woo-Jae; Lim, Young Woon
A new species, Trichoderma songyi, was found to be associated with the pine mushroom (Tricholoma matsutake) in Korea. This species was isolated from three different substrates: Tricholoma matsutake basidiomata, as well as roots of Pinus densiflora and soil in the fairy ring. Based on its molecular and phenotypic characteristics, we demonstrate that Trichoderma songyi is unique and distinguishable from closely related species. We performed phylogenetic analyses based on two molecular markers, the genes for both translation elongation factor 1-alpha and the second largest subunit of RNA polymerase II. Phylogenetic analyses showed that Trichoderma songyi is closely related to Trichoderma koningii aggregate and Trichoderma caerulescens. Morphologically, Trichoderma songyi can be distinguished from these closely related taxa by its growth rates, colony morphology on PDA in darkness, and coconut-like odour. Due to the economic importance of the pine mushroom, the relationship between Trichoderma songyi and Tricholoma matsutake should be studied further.
姚日生; 李曼曼; 邓胜松; 胡华佳; 王淮; 李凤和
Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet （UV） and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.
Yao, Risheng; Li, Manman; Deng, Shengsong; Hu, Huajia; Wang, Huai; Li, Fenghe
Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.
Fernandes, Elio Gomes; Pereira, Olinto Liparini; da Silva, Cynthia Cânedo; Bento, Claudia Braga Pereira; de Queiroz, Marisa Vieira
Endophytic fungi are microorganisms that live within plant tissues without causing disease during part of their life cycle. With the isolation and identification of these fungi, new species are being discovered, and ecological relationships with their hosts have also been studied. In Glycine max, limited studies have investigated the isolation and distribution of endophytic fungi throughout leaves and roots. The distribution of these fungi in various plant organs differs in diversity and abundance, even when analyzed using molecular techniques that can evaluate fungal communities in different parts of the plants, such as denaturing gradient gel electrophoresis (DGGE). Our results show there is greater species richness of culturable endophytic filamentous fungi in the leaves G. max as compared to roots. Additionally, the leaves had high values for diversity indices, i.e. Simpsons, Shannon and Equitability. Conversely, dominance index was higher in roots as compared to leaves. The fungi Ampelomyces sp., Cladosporium cladosporioides, Colletotrichum gloeosporioides, Diaporthe helianthi, Guignardia mangiferae and Phoma sp. were more frequently isolated from the leaves, whereas the fungi Fusarium oxysporum, Fusarium solani and Fusarium sp. were prevalent in the roots. However, by evaluating the two communities by DGGE, we concluded that the species richness was higher in the roots than in the leaves. UPGMA analysis showed consistent clustering of isolates; however, the fungus Leptospora rubella, which belongs to the order Dothideales, was grouped among species of the order Pleosporales. The presence of endophytic Fusarium species in G. max roots is unsurprising, since Fusarium spp. isolates have been previously described as endophyte in other reports. However, it remains to be determined whether the G. max Fusarium endophytes are latent pathogens or non-pathogenic forms that benefit the plant. This study provides a broader knowledge of the distribution of the fungal
Siddaiah, Chandra Nayaka; Satyanarayana, Niranjan Raj; Mudili, Venkataramana; Kumar Gupta, Vijai; Gurunathan, Selvakumar; Rangappa, Shobith; Huntrike, Shekar Shetty; Srivastava, Rakesh Kumar
Endophytic Trichoderma hamatum UoM 13 isolated from pearl millet roots was evaluated for its efficiency to suppress downy mildew disease. Under laboratory conditions, T. hamatum seed treatment significantly enhanced pearl millet seed germination and seedling vigor. T. hamatum seed treatment resulted in systemic and durable immunity against pearl millet downy mildew disease under greenhouse and field conditions. T. hamatum treated seedlings responded to downy mildew infection with high lignification and callose deposition. Analysis of defense enzymes showed that T. hamatum treatment significantly enhanced the activities of glucanase, peroxidase, phenylalanine ammonia-lyase, and polyphenol oxidase in comparison to untreated control. RT-PCR analysis revealed differentially expressed transcripts of the defense enzymes and PR-proteins in treated, untreated, and checks, wherein PR-1, PR-5, and cell wall defense HRGPs were significantly over expressed in treated seedlings as against their lower expression in controls. T. hamatum treatment significantly stimulated endogenous salicylic acid (SA) levels and significantly upregulated important SA biosynthesis gene isochorismate synthase. The results indicated that T. hamatum UoM13 treatment induces resistance corresponding to significant over expression of endogenous SA, important defense enzymes, PR-proteins, and HRGPs, suggesting that SA biosynthetic pathway is involved in pearl millet for mounting systemic immunity against downy mildew pathogen. PMID:28322224
XUQingyan; WANGJianfeng; HUANGYaojian; ZHENGZhonghui; SONGSiyang; ZHANGYongmin; SUWenjin
Mangroves are special woody plant communities in the intertidal zone of tropical and subtropical coasts. They prove to be a natural microorganisms and new metabolites storage. In the study of mangrove endophytic fungi metabolites, four new compounds, Compounds 1, 2, 3 and 4, as well as a known octaketide, cytosporone B (5), are isolated from an endophytic fungus, Dothiorella sp., HTF3. They all show cytotoxic activities. The elucidation of these structures is mainly based on 1D/2D NMR and ESI-MS spectral analyses.
Full Text Available Endophytic fungi are capable of producing plant associated metabolites and their analogs with therapeutic value. In order to identify the potential endophytic isolates producing bioactive compounds, one need to screen all isolated endophytes, which may run into hundreds. Isolation of endophytic fungi is relatively a simple process; but screening of the isolated fungi for required metabolite production is a cumbersome process. Endophytic fungi producing plant associated metabolites may contain genes involved in the entire biosynthetic pathway(s. Therefore, ascertaining the presence of key enzymes of a particular biosynthetic pathway could serve as a molecular marker for screening of these endophytes to produce that metabolite. In absence of entire biosynthetic pathways in endophytic fungi, plant genes associated with that metabolic pathway could serve as markers. This review focuses on the impact of molecular approaches to screen the endophytic fungi for the production of bioactive compounds. An attempt has been made on screening of anticancer compounds like taxol (paclitaxel, podophyllotoxin and camptothecin using molecular markers. The advantages of molecular approaches over conventional methods to screen endophytic fungi and also identification of endophytic fungi are also discussed.
Vasundhara, M; Kumar, Anil; Reddy, M Sudhakara
Endophytic fungi are capable of producing plant associated metabolites and their analogs with therapeutic value. In order to identify the potential endophytic isolates producing bioactive compounds, one need to screen all isolated endophytes, which may run into hundreds. Isolation of endophytic fungi is relatively a simple process; but screening of the isolated fungi for required metabolite production is a cumbersome process. Endophytic fungi producing plant associated metabolites may contain genes involved in the entire biosynthetic pathway(s). Therefore, ascertaining the presence of key enzymes of a particular biosynthetic pathway could serve as a molecular marker for screening of these endophytes to produce that metabolite. In absence of entire biosynthetic pathways in endophytic fungi, plant genes associated with that metabolic pathway could serve as markers. This review focuses on the impact of molecular approaches to screen the endophytic fungi for the production of bioactive compounds. An attempt has been made on screening of anticancer compounds like taxol (paclitaxel), podophyllotoxin, and camptothecin using molecular markers. The advantages of molecular approaches over conventional methods to screen endophytic fungi and also identification of endophytic fungi are discussed.
Full Text Available Species of Trichoderma exert direct biocontrol activity against soil-borne plant pathogens due to their ability to compete for nutrients and to inhibit or kill their targets through the production of antibiotics and/or hydrolytic enzymes. In addition to these abilities, Trichoderma spp. have beneficial effects for plants, including the stimulation of defenses and the promotion of growth. Here we study the role in biocontrol of the T. parareesei Tparo7 gene, encoding a chorismate mutase (CM, a shikimate pathway branch point leading to the production of aromatic amino acids, which are not only essential components of protein synthesis but also the precursors of a wide range of secondary metabolites. We isolated T. parareesei transformants with the Tparo7 gene silenced. Compared with the wild-type, decreased levels of Tparo7 expression in the silenced transformants were accompanied by reduced CM activity, lower growth rates on different culture media, and reduced mycoparasitic behavior against the phytopathogenic fungi Rhizoctonia solani, Fusarium oxysporum and Botrytis cinerea in dual cultures. By contrast, higher amounts of the aromatic metabolites tyrosol, 2-phenylethanol and salicylic acid were detected in supernatants from the silenced transformants, which were able to inhibit the growth of F. oxysporum and B. cinerea. In in vitro plant assays, Tparo7-silenced transformants also showed a reduced capacity to colonize tomato roots. The effect of Tparo7-silencing on tomato plant responses was examined in greenhouse assays. The growth of plants colonized by the silenced transformants was reduced and the plants exhibited an increased susceptibility to B. cinerea in comparison with the responses observed for control plants. In addition, the plants turned yellowish and were defective in jasmonic acid- and ethylene-regulated signaling pathways which was seen by expression analysis of lipoxygenase 1 (LOX1, ethylene-insensitive protein 2 (EIN2 and
Sarah L Dodd; Alison Stewart
@@ With increased imports of foreign microbes either as commercial biocontrol products or for the purposes of research, there is potentially an increased threat to indigenous beneficial microflora. In the present study, indigenous species of the fungal genus Hypocrea/Trichoderma are being used as a model system to determine the impact of foreign microbes on the native microflora of New Zealand. In order to protect such microflora, one has to first be aware of what is currently present and what sites, if any,are most vulnerable. A preliminary survey for the presence and diversity of species of Hypocrea/Trichoderma is currently underway in New Zealand and samples are being assessed from forest soils,agricultural soils, orchards, garden soils, sclerotia of various plant pathogens and pasture land. To date 238 isolates have been identified using both morphological characters and DNA sequence data from the ITS regions of the ribosomal gene cluster (ITS1 & ITS2) and, in some instances, sequence of the elongation factor gene (EF1-α) . Isolates were found to represent 16 known species plus three species as yet undescribed. In forest soils T. harzianum /T. inhamatum (31%) and T. viride (29%)followed by T. fertile (13%), were clearly the most abundant species and the remaining five species found in forests ( T. atroviride, T. koningii, T. aureoviride, H. cf. flavovirens anamorph and one unknown) each accounting for ＜8% of the total. Dominance by the species T. harzianum/inhamatum is consistent with studies done in South-East Asia, a mid-European primeval floodplainforest and Moscow. In contrast, when isolations were conducted with a bias for biocontrol capabilities it was found that the species T. atroviride (29%), T. koningii (17%), T. harzianum (15%)and T. viride (12%) dominated respectively. This survey is currently ongoing in New Zealand.Future studies will monitor indigenous species and strains following inoculation of specific microbes to assess the impact of the
Li, Meiya; Wu, Yunwei; Jiang, Fusheng; Yu, Xiangli; Tang, Kexuan; Miao, Zhiqi
The endophytic fungus named FSN006 was isolated from the inner bark of Juglans mandshurica. It grew quickly and formed circular colony on PDA plate. The upper side of the colony was white, while the lower side of the colony and the conditioned medium were light yellow as a result of significant yellow pigment substances were produced and secreted by the fungi. Green elliptic conidia appeared when cultured on CMX plate. Based on the morphology identification and ITS sequence, it was clear that this fungus belonged to the Deuteromycotina, HyPhomycetes, Moniliales, Trichoderma longibrachiatum. The conditioned medium of FSN006 showed a high anti-tumor ability against liver cancer cell-HepG2, and reached its IC50 concentration after being diluted 20 times, while the IC50 concentration of curcumine was(11.49 +/- 0.12) mg x L(-1). In addition, there was preeminent selective inhibiting effect against the normal liver cell strain HL-7702 and its caner counter strain HepG2. The inhibiting effect against strain HL-7702 was only one quarter of that against HepG2 at the concentration of IC50. Therefore, the fermentation of FSN006 may provide a possible way to produce anticancer drug with higher efficiency and lower toxicity.
Pohjanen, Johanna; Koskimäki, Janne J; Sutela, Suvi; Ardanov, Pavlo; Suorsa, Marja; Niemi, Karoliina; Sarjala, Tytti; Häggman, Hely; Pirttilä, Anna Maria
Tissues of Scots pine (Pinus sylvestris L.) contain several endophytic microorganisms of which Methylobacterium extorquens DSM13060 is a dominant species throughout the year. Similar to other endophytic bacteria, M. extorquens is able to colonize host plant tissues without causing any symptoms of disease. In addition to endophytic bacteria, plants associate simultaneously with a diverse set of microorganisms. Furthermore, plant-colonizing microorganisms interact with each other in a species- or strain-specific manner. Several studies on beneficial microorganisms interacting with plants have been carried out, but few deal with interactions between different symbiotic organisms and specifically, how these interactions affect the growth and development of the host plant. Our aim was to study how the pine endophyte M. extorquens DSM13060 affects pine seedlings and how the co-inoculation with ectomycorrhizal (ECM) fungi [Suillus variegatus (SV) or Pisolithus tinctorius (PT)] alters the response of Scots pine. We determined the growth, polyamine and nutrient contents of inoculated and non-inoculated Scots pine seedlings in vitro. Our results show that M. extorquens is able to improve the growth of seedlings at the same level as the ECM fungi SV and PT do. The effect of co-inoculation using different symbiotic organisms was seen in terms of changes in growth and nutrient uptake. Inoculation using M. extorquens together with ECM fungi improved the growth of the host plant even more than single ECM inoculation. Symbiotic organisms also had a strong effect on the potassium content of the seedling. The results indicate that interaction between endophyte and ECM fungus is species dependent, leading to increased or decreased nutrient content and growth of pine seedlings.
Yokoya, Kazutomo; Postel, Sarah; Fang, Rui
Background Fungal endophytes are highly diverse ubiquitous asymptomatic microorganisms, some of which appear to be symbiotic. Depending on abiotic conditions and genotype of the plant, the diversity of endophytes may confer fitness benefits to plant communities. Methods We studied a crop wild relative (CWR) of strawberry, along environmental gradients with a view to understand the cultivable root-derived endophytic fungi that can be evaluated for promoting growth and tolerating stress in selected plant groups. The main objectives were to understand whether: (a) suboptimal soil types are drivers for fungal distribution and diversity; (b) high pH and poor nutrient availability lead to fungal-plant associations that help deliver fitness benefits; and (c) novel fungi can be identified for their use in improving plant growth, and alleviate stress in diverse crops. Results The study revealed that habitats with high pH and low nutrient availability have higher fungal diversity, with more rare fungi isolated from locations with chalky soil. Plants from location G were the healthiest even though soil from this location was the poorest in nutrients. Study of environmental gradients, especially extreme habitat types, may help understand the root zone fungal diversity of different functional classes. Two small in vitro pilot studies conducted with two isolates showed that endophytic fungi from suboptimal habitats can promote plant growth and fitness benefits in selected plant groups. Discussion Targeting native plants and crop wild relatives for research offers opportunities to unearth diverse functional groups of root-derived endophytic fungi that are beneficial for crops. PMID:28168102
Ryder, Lauren S; Harris, Beverley D; Soanes, Darren M; Kershaw, Michael J; Talbot, Nicholas J; Thornton, Christopher R
Trichoderma species are ubiquitous soil fungi that hold enormous potential for the development of credible alternatives to agrochemicals and synthetic fertilizers in sustainable crop production. In this paper, we show that substantial improvements in plant productivity can be met by genetic modification of a plant-growth-promoting and biocontrol strain of Trichoderma hamatum, but that these improvements are obtained in the absence of disease pressure only. Using a quantitative monoclonal antibody-based ELISA, we show that an N-acetyl-β-d-glucosaminidase-deficient mutant of T. hamatum, generated by insertional mutagenesis of the corresponding gene, has impaired saprotrophic competitiveness during antagonistic interactions with Rhizoctonia solani in soil. Furthermore, its fitness as a biocontrol agent of the pre-emergence damping-off pathogen Sclerotinia sclerotiorum is significantly reduced, and its ability to promote plant growth is constrained by the presence of both pathogens. This work shows that while gains in T. hamatum-mediated plant-growth-promotion can be met through genetic manipulation of a single beneficial trait, such a modification has negative impacts on other aspects of its biology and ecology that contribute to its success as a saprotrophic competitor and antagonist of soil-borne pathogens. The work has important implications for fungal morphogenesis, demonstrating a clear link between hyphal architecture and secretory potential. Furthermore, it highlights the need for a holistic approach to the development of genetically modified Trichoderma strains for use as crop stimulants and biocontrol agents in plant agriculture.
Zafra, German; Cortés-Espinosa, Diana V
Fungi belonging to Trichoderma genus are ascomycetes found in soils worldwide. Trichoderma has been studied in relation to diverse biotechnological applications and are known as successful colonizers of their common habitats. Members of this genus have been well described as effective biocontrol organisms through the production of secondary metabolites with potential applications as new antibiotics. Even though members of Trichoderma are commonly used for the commercial production of lytic enzymes, as a biological control agent, and also in the food industry, their use in xenobiotic biodegradation is limited. Trichoderma stands out as a genus with a great range of substrate utilization, a high production of antimicrobial compounds, and its ability for environmental opportunism. In this review, we focused on the recent advances in the research of Trichoderma species as potent and efficient aromatic hydrocarbon-degrading organisms, as well as aimed to provide insight into its potential role in the bioremediation of soils contaminated with heavy hydrocarbons. Several Trichoderma species are associated with the ability to metabolize a variety of both high and low molecular weight polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, chrysene, pyrene, and benzo[a]pyrene. PAH-degrading species include Trichoderma hamatum, Trichoderma harzianum, Trichoderma reesei, Trichoderma koningii, Trichoderma viride, Trichoderma virens, and Trichoderma asperellum using alternate enzyme systems commonly seen in other organisms, such as multicooper laccases, peroxidases, and ring-cleavage dioxygenases. Within these species, T. asperellum stands out as a versatile organism with remarkable degrading abilities, high tolerance, and a remarkable potential to be used as a remediation agent in polluted soils.
Simpson, B.K.; Oldham, J.H.; Martin, A.M
Laboratory results are presented of the bioconversion of cellulose from cocoa pod husks, utilizing cellulase from three mutants of Trichoderma reesei. Total reducing sugars in filtered hydrolysates were estimated by the dinitrosalicylic acid method. The sugars present were identified by paper chromatography as glucose and xylose.
Xie, Bin-Bin; Qin, Qi-Long; Shi, Mei; Chen, Lei-Lei; Shu, Yan-Li; Luo, Yan; Wang, Xiao-Wei; Rong, Jin-Cheng; Gong, Zhi-Ting; Li, Dan; Sun, Cai-Yun; Liu, Gui-Ming; Dong, Xiao-Wei; Pang, Xiu-Hua; Huang, Feng; Liu, Weifeng; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong; Song, Xiao-Yan
Saprotrophy on plant biomass is a recently developed nutrition strategy for Trichoderma. However, the physiology and evolution of this new nutrition strategy is still elusive. We report the deep sequencing and analysis of the genome of Trichoderma longibrachiatum, an efficient cellulase producer. The 31.7-Mb genome, smallest among the sequenced Trichoderma species, encodes fewer nutrition-related genes than saprotrophic T. reesei (Tr), including glycoside hydrolases and nonribosomal peptide synthetase-polyketide synthase. Homology and phylogenetic analyses suggest that a large number of nutrition-related genes, including GH18 chitinases, β-1,3/1,6-glucanases, cellulolytic enzymes, and hemicellulolytic enzymes, were lost in the common ancestor of T. longibrachiatum (Tl) and Tr. dN/dS (ω) calculation indicates that all the nutrition-related genes analyzed are under purifying selection. Cellulolytic enzymes, the key enzymes for saprotrophy on plant biomass, are under stronger purifying selection pressure in Tl and Tr than in mycoparasitic species, suggesting that development of the nutrition strategy of saprotrophy on plant biomass has increased the selection pressure. In addition, aspartic proteases, serine proteases, and metalloproteases are subject to stronger purifying selection pressure in Tl and Tr, suggesting that these enzymes may also play important roles in the nutrition. This study provides insights into the physiology and evolution of the nutrition strategy of Trichoderma.
Ramadan, Metwaly; Gigolashvili, Tamara; Grosskinsky, Dominik Kilian;
of Trichoderma asperellum IsmT5 on Arabidopsis thaliana. During co-cultivation of T. asperellum IsmT5 without physical contact to A. thaliana we observed smaller but vital and robust plants. The exposed plants exhibit increased trichome numbers, accumulation of defense-related compounds such as H2O2, anthocyanin...
Yang, J; Li, B; Liu, S W; Biswas, M K; Liu, S; Wei, Y R; Zuo, C W; Deng, G M; Kuang, R B; Hu, C H; Yi, G J; Li, C Y
Fusarium wilt (also known as Panama disease) is one of the most destructive banana diseases, and greatly hampers the global production of bananas. Consequently, it has been very detrimental to the Chinese banana industry. An infected plant is one of the major causes of the spread of Fusarium wilt to nearby regions. It is essential to develop an efficient and environmentally sustainable disease control method to restrict the spread of Fusarium wilt. We isolated Trichoderma spp from the rhizosphere soil, roots, and pseudostems of banana plants that showed Fusarium wilt symptoms in the infected areas. Their cellulase activities were measured by endoglucanase activity, β-glucosidase activity, and filter paper activity assays. Safety analyses of the Trichoderma isolates were conducted by inoculating them into banana plantlets. The antagonistic effects of the Trichoderma spp on the Fusarium pathogen Foc tropical Race 4 (Foc TR4) were tested by the dual culture technique. Four isolates that had high cellulase activity, no observable pathogenicity to banana plants, and high antagonistic capability were identified. The isolates were used to biodegrade diseased banana plants infected with GFP-tagged Foc TR4, and the compost was tested for biological control of the infectious agent; the results showed that the fermentation suppressed the incidence of wilt and killed the pathogen. This study indicates that Trichoderma isolates have the potential to eliminate the transmission of Foc TR4, and may be developed into an environmentally sustainable treatment for controlling Fusarium wilt in banana plants.
Mayerhofer, Michael S; Fraser, Erica; Kernaghan, Gavin
Fungal endophytes are ubiquitous in healthy root tissue, but little is known about their ecosystem functions, including their ability to utilize organic nutrient sources such as proteins. Root-associated fungi may secrete proteases to access the carbon and mineral nutrients within proteins in the soil or in the cells of their plant host. We compared the protein utilization patterns of multiple isolates of the root endophytes Phialocephala fortinii s.l., Meliniomyces variabilis and Umbelopsis isabellina with those of two ectomycorrhizal (ECM) fungi, Hebeloma incarnatulum and Laccaria bicolor, and the wood-decay fungus Irpex lacteus at pH values of 2-9 on liquid BSA media. We also assessed protease activity using a fluorescently labeled casein assay and gelatin zymography and characterized proteases using specific protease inhibitors. I. lacteus and U. isabellina utilized protein efficiently, while the ECM fungi exhibited poor protein utilization. ECM fungi secreted metallo-proteases and had pH optima above 4, while other fungi produced aspartic proteases with lower pH optima. The ascomycetous root endophytes M. variabilis and P. fortinii exhibited intermediate levels of protein utilization and M. variabilis exhibited a very low pH optimum. Comparing proteolytic profiles between fungal root endophytes and fungi with well defined ecological roles provides insight into the ecology of these cryptic root associates.
Powell, R G; Petroski, R J
Grasses infected with clavicipitaceous fungi have been associated with a variety of diseases including classical ergotism in humans and animals, fescue foot and summer syndrome in cattle, and rye-grass staggers in sheep. During the last decade it has been recognized that many of these fungal infections are endophytic; a fungal endophyte is a fungus that grows entirely within the host plant. Inspection of field collections and herbarium specimens has revealed that such infections are widespread in grasses. The chemistry associated with these grass-fungal interactions has proved to be interesting and complex, as each grass-fungal pair results in a unique "fingerprint" of various alkaloids, of which some are highly toxic to herbivores. In many cases the presence of an endophyte appears to benefit the plant by increasing drought resistance, or by increasing resistance to attack by insects, thus improving the overall survivability of the grass. This review will focus on alkaloids that have been reported in endophyte-infected grasses.
Wikee, S.; Lombard, L.; Crous, P.W.; Nakashima, C.; Motohashi, K.; Chukeatirote, E.; Alias, S.A.; McKenzie, E.H.C.; Hyde, K.D.
Phyllosticta capitalensis is an endophyte and weak plant pathogen with a worldwide distribution presently known from 70 plant families. This study isolated P. capitalensis from different host plants in northern Thailand, and determined their different life modes. Thirty strains of P. capitalensis we
Zhang, Gao-Fei; Guo, Zhi-Kai; Wang, Wei; Cui, Jiang-Tao; Tan, Ren-Xiang; Ge, Hui-Ming
The chemical study of endophytic fungus of Cochliobolus led to the isolation of 10 terpenes (1-10), including one new compound named isocochlioquinone B (1). Their structures were elucidated on the basis of spectroscopic methods, including 2D NMR techniques. Compounds 5-7 showed significant neuraminidase inhibitory activity with IC(50) values of 0.79-1.75 μM.
Zida, E P; Thio, I G; Néya, B J
A survey was conducted to assess the natural occurrence and distribution of fungal endophytes in sorghum in relation to plant performance in two distinct agro-ecological zones in Burkina Faso. Sorghum farm-saved seeds were sown in 48 farmers’ fields in Sahelian and North Sudanian zones to produce...
Diaz, Patricia L; Hennell, James R; Sucher, Nikolaus J
Endophytes live inter- and/or intracellularly inside healthy aboveground tissues of plants without causing disease. Endophytic fungi are found in virtually every vascular plant species examined. The origins of this symbiotic relationship between endophytes go back to the emergence of vascular plants. Endophytic fungi receive nutrition and protection from their hosts while the plants benefit from the production of fungal secondary metabolites, which enhance the host plants' resistance to herbivores, pathogens, and various abiotic stresses. Endophytic fungi have attracted increased interest as potential sources of secondary metabolites with agricultural, industrial, and medicinal use. This chapter provides detailed protocols for isolation of genomic DNA from fungal endophytes and its use in polymerase chain reaction-based amplification of the internal transcribed spacer region between the conserved flanking regions of the small and large subunit of ribosomal RNA for barcoding purposes.
Yousaf, Sohail [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); Afzal, Muhammad [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad (Pakistan); Reichenauer, Thomas G. [AIT Austrian Institute of Technology GmbH, Environmental Resources and Technologies Unit, A-2444 Seibersdorf (Austria); Brady, Carrie L. [Forestry and Agricultural Biotechnology Institute, Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria (South Africa); Sessitsch, Angela, E-mail: email@example.com [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria)
The genus Enterobacter comprises a range of beneficial plant-associated bacteria showing plant growth promotion. Enterobacter ludwigii belongs to the Enterobacter cloacae complex and has been reported to include human pathogens but also plant-associated strains with plant beneficial capacities. To assess the role of Enterobacter endophytes in hydrocarbon degradation, plant colonization, abundance and expression of CYP153 genes in different plant compartments, three plant species (Italian ryegrass, birdsfoot trefoil and alfalfa) were grown in sterile soil spiked with 1% diesel and inoculated with three endophytic E. ludwigii strains. Results showed that all strains were capable of hydrocarbon degradation and efficiently colonized the rhizosphere and plant interior. Two strains, ISI10-3 and BRI10-9, showed highest degradation rates of diesel fuel up to 68% and performed best in combination with Italian ryegrass and alfalfa. All strains expressed the CYP153 gene in all plant compartments, indicating an active role in degradation of diesel in association with plants. - Highlights: > E. ludwigii strains efficiently colonized plants in a non-sterile soil environment. > E. ludwigii strains efficiently expressed alkane degradation genes in plants. > E. ludwigii efficiently degraded alkane contaminations and promoted plant growth. > E. ludwigii interacted more effectively with Italian ryegrass than with other plants. > Degradation activity varied with plant and microbial genotype as well as with time. - Enterobacter ludwigii strains belonging to the E. cloacae complex are able to efficiently degrade alkanes when associated with plants and to promote plant growth.
Monte E; Hermosa M R; González F J; Rey M; Cardoza R E; Gutiérrez S; Delgado Jarana J; Llobell A
@@ Trichoderma is a fungal genus of great and demonstrable biotechnological value, but its genome is poorly surveyed compared with other model microorganisms. Due to their ubiquity and rapid substrate colonization, Trichoderma species have been widely used as biocontrol organisms for agriculture, and their enzyme systems are widely used in industry. Therefore, there is a clear interest to explore beyond the phenotype to exploit the underlying genetic systems using functional genomics tools. The great diversity of species within the Trichoderma genus, the absence of optimized systems for its exploration, and the great variety of genes expressed under a wide range of ambient conditions are the main challenges to consider when starting a comprehensive functional genomics study. An initial project started by three Spanish groups has been extended into the project TRICHOEST, funded by the EU (FP5, QLRT-2001-02032) to target the transcriptome analysis of selected Trichoderma strains with biocontrol potential, in conditions related to antagonism, nutrient stress and plant interactions. Once specific conditions were defined, cDNA libraries were produced and used for EST sequencing. Nine strains from seven Trichoderma species have been considered in this study and an important amount of gene sequence data has been generated, analyzed and used to compare the gene expression in different strains.In parallel to sequencing, genomic expression studies were carried out by means of macro-arrays to identify genes expressed in specific conditions. In silico analysis of DNA sequencing data together with macro-array expression results have lead to a selection based on the potential use of the gene sequences.The selected clone sequences were completed and cloned in appropriate vectors to initiate functional analysis by means of expression studies in homologous and heterologous systems.
Chaudhary, Nitika; Kumari, Indu; Sandhu, Padmani; Ahmed, Mushtaq; Akhter, Yusuf
Trichoderma spp. have been acknowledged as potent bio-control agents against microbial pathogens and also as plant growth promoters. Various secondary metabolites are attributed for these beneficial activities. Major facilitator superfamily (MFS) includes the large proportion of efflux-pumps which are linked with membrane transport of these secondary metabolites. We have carried out a proteome-wide identification of MFS transporters using protein sequence and structure based hierarchical method in Trichoderma reesei. 448 proteins out of 9115 were detected to carry transmembrane helices. MFS specific intragenic gene duplication and its context with transport function have been presented. Finally, using homology based techniques, domains and motifs of MFS families have been identified and utilized to classify them. From query dataset of 448 transmembrane proteins, 148 proteins are identified as potential MFS transporters. Sugar porter, drug: H(+) antiporter-1, monocarboxylate porter and anion: cation symporter emerged as major MFS families with 51, 35, 17 and 11 members respectively. Representative protein tertiary structures of these families are homology modeled for structure-function analysis. This study may help to understand the molecular basis of secretion and transport of agriculturally valuable secondary metabolites produced by these bio-control fungal agents which may be exploited in future for enhancing its biotechnological applications in eco-friendly sustainable development.
Aly, A H; Debbab, A; Proksch, P
The potential of endophytic fungi as promising sources of bioactive natural products continues to attract broad attention. Endophytic fungi are defined as fungi that live asymptomatically within the tissues of higher plants. This overview will highlight the uniqueness of endophytic fungi as alternative sources of pharmaceutically valuable compounds originally isolated from higher plants, e.g. paclitaxel, camptothecin and podophyllotoxin. In addition, it will shed light on the fungal biosynthesis of plant associated metabolites as well as new approaches developed to improve the production of commercially important plant derived compounds with the involvement of endophytic fungi.
Saikkonen, Kari; Gundel, Pedro E; Helander, Marjo
Defensive mutualism is widely accepted as providing the best framework for understanding how seed-transmitted, alkaloid producing fungal endophytes of grasses are maintained in many host populations. Here, we first briefly review current knowledge of bioactive alkaloids produced by systemic grass-endophytes. New findings suggest that chemotypic diversity of the endophyte-grass symbiotum is far more complex, involving multifaceted signaling and chemical cross-talk between endophyte and host cells (e.g., reactive oxygen species and antioxidants) or between plants, herbivores, and their natural enemies (e.g., volatile organic compounds, and salicylic acid and jasmonic acid pathways). Accumulating evidence also suggests that the tight relationship between the systemic endophyte and the host grass can lead to the loss of grass traits when the lost functions, such as plant defense to herbivores, are compensated for by an interactive endophytic fungal partner. Furthermore, chemotypic diversity of a symbiotum appears to depend on the endophyte and the host plant life histories, as well as on fungal and plant genotypes, abiotic and biotic environmental conditions, and their interactions. Thus, joint approaches of (bio)chemists, molecular biologists, plant physiologists, evolutionary biologists, and ecologists are urgently needed to fully understand the endophyte-grass symbiosis, its coevolutionary history, and ecological importance. We propose that endophyte-grass symbiosis provides an excellent model to study microbially mediated multirophic interactions from molecular mechanisms to ecology.
Sandoval-Denis, Marcelo; Sutton, Deanna A; Cano-Lira, José F; Gené, Josepa; Fothergill, Annette W; Wiederhold, Nathan P; Guarro, Josep
A set of 73 isolates of the emerging fungus Trichoderma isolated from human and animal clinical specimens were characterized morphologically and molecularly using a multilocus sequence analysis that included the internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA and fragments of the translation elongation factor 1 alpha (Tef1), endochitinase CHI18-5 (Chi18-5), and actin 1 (Act1) genes. The most frequent species was Trichoderma longibrachiatum (26%), followed by Trichoderma citrinoviride (18%), the Hypocrea lixii/Trichoderma harzianum species complex (15%), the newly described species Trichoderma bissettii (12%), and Trichoderma orientale (11%). The most common anatomical sites of isolation in human clinical specimens were the respiratory tract (40%), followed by deep tissue (30%) and superficial tissues (26%), while all the animal-associated isolates were obtained from superficial tissue samples. Susceptibilities of the isolates to eight antifungal drugs in vitro showed mostly high MICs, except for voriconazole and the echinocandins.
Jennifer W. MacAdam
Full Text Available The two temperate forage legumes containing condensed tannins (CT that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT and sainfoin (Onobrychis viciifolia Scop.; SF. Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM, while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb. Dumort. forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.
The present study includes the molecular characteristics of Trichoderma pleurotum and Trichoderma pleuroticola isolates collected from green moulded cereal straw substrates at 47 oyster mushroom farms in Poland. The screening of the 80 Trichoderma isolates was performed by morphological observation and by using the multiplex PCR assay. This approach enabled specific detection of 47 strains of T. pleurotum and 2 strains of T. pleuroticola. Initial identifications were confirmed by sequencing t...
LIU Xian; ZHUANG Jing-hua; GAO Zeng-gui; YANG Chang-cheng; CHEN Jie
@@ The transformed Trichoderma strains Ttrm31, Ttrm34 and Ttrm55 were obtained from Trichoderma wild strain T21 mutated by REMI technique for more effective biocontrol of tomato gray mold (Botrytis cinerea) with Trichoderma agent. Those transformants appeared much better in biocontrol activity in vitro or in vivo against tomato gray mold were better than that of wild strain T21. The main results were as follow:
Full Text Available Endophytes form symbiotic relationships with plants and constitute an important source of phytohormones and bioactive secondary metabolites for their hosts. To date, most studies of endophytes have focused on the influence of these microorganisms on plant growth and physiology and their role in plant defenses against biotic and abiotic stressors; however, to the best of our knowledge, the ability of endophytes to produce melatonin has not been reported. In the present study, we isolated and identified root-dwelling bacteria from three grapevine varieties and found that, when cultured under laboratory conditions, some of the bacteria strains secreted melatonin and tryptophan-ethyl ester. The endophytic bacterium Bacillus amyloliquefaciens SB-9 exhibited the highest level of in vitro melatonin secretion and also produced three intermediates of the melatonin biosynthesis pathway: 5-hydroxytryptophan, serotonin, and N-acetylserotonin. After B. amyloliquefaciens SB-9 colonization, the plantlets exhibited increased plant growth. Additionally, we found that, in grapevine plantlets exposed to salt or drought stress, colonization by B. amyloliquefaciens SB-9 increased the upregulation of melatonin synthesis, as well as that of its intermediates, but reduced the upregulation of grapevine tryptophan decaboxylase genes (VvTDCs and a serotonin N-acetyltransferase gene (VvSNAT transcription, when compared to the un-inoculated control. Colonization by B. amyloliquefaciens SB-9 was also able to counteract the adverse effects of salt- and drought-induced stress by reducing the production of malondialdehyde and reactive oxygen species (H2O2 and O2− in roots. Therefore, our findings demonstrate the occurrence of melatonin biosynthesis in endophytic bacteria and provide evidence for a novel form of communication between beneficial endophytes and host plants via melatonin.
Molnár-Gábor, Etelka; Dóczi, Ilona; Hatvani, Lóránt; Vágvölgyi, Csaba; Kredics, László
We present a case of isolated sinusitis sphenoidalis caused by Trichoderma longibrachiatum, an emerging causal agent of fungal infections with an often fatal outcome. A Trichoderma strain was isolated from secretion obtained from the sinus sphenoidalis of a rhinosinusitis patient and identified by sequence analysis of two loci as Trichoderma longibrachiatum from the Longibrachiatum Clade of the genus Trichoderma. T. longibrachiatum can trigger a fatal pathomechanism in immunodeficient patients, but only rarely causes disease in healthy people. The case presented is unique because the patient was not immunocompromised.
Mitchell, Angela M; Strobel, Gary A; Moore, Emily; Robison, Richard; Sears, Joe
Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.
Full Text Available The basidiomycete fungus Crinipellis perniciosa (Stahel Singer is the causal agent of Witches' Broom Disease of Cacao (Theobroma cacao L. which is the main factor limiting cacao production in the Americas. Pod losses of up to 90% are experienced in affected areas as evidenced by the 50% drop in production in Bahia province, Brazil following the arrival of the C. perniciosa in the area in 1989. The disease has proven particularly difficult to control and many farmers in affected areas have given up cacao cultivation. In order to evaluate the potential of endophytes as a biological control agent of this phytopathogen, the endophytic fungal community of resistant and susceptible cacao plants as well as affected branches was studied between 2001 and 2002. The fungal community was identified by morphological traits and rDNA sequencing as belonging to the genera Acremonium, Blastomyces, Botryosphaeria, Cladosporium, Colletotrichum, Cordyceps, Diaporthe, Fusarium, Geotrichum, Gibberella, Gliocladium, Lasiodiplodia, Monilochoetes, Nectria, Pestalotiopsis, Phomopsis, Pleurotus, Pseudofusarium, Rhizopycnis, Syncephalastrum, Trichoderma, Verticillium and Xylaria. These fungi were evaluated both in vitro and in vivo by their ability to inhibit C. perniciosa. Among these, some were identified as potential antagonists, but only one fungus (Gliocladium catenulatum reduced the incidence of Witches' Broom Disease in cacao seedlings to 70%.
López-Quintero, Carlos A; Atanasova, Lea; Franco-Molano, A Esperanza; Gams, Walter; Komon-Zelazowska, Monika; Theelen, Bart; Müller, Wally H; Boekhout, Teun; Druzhinina, Irina
The diversity of Trichoderma (Hypocreales, Ascomycota) colonizing leaf litter as well as the rhizosphere of Garcinia macrophylla (Clusiaceae) was investigated in primary and secondary rain forests in Colombian Amazonia. DNA barcoding of 107 strains based on the internal transcribed spacers 1 and 2 (ITS1 and 2) of the ribosomal RNA gene cluster and the partial sequence of the translation elongation factor 1 alpha (tef1) gene revealed that the diversity of Trichoderma was dominated (71 %) by three common cosmopolitan species, namely Trichoderma harzianum sensu lato (41 %), Trichoderma spirale (17 %) and Trichoderma koningiopsis (13 %). Four ITS 1 and 2 phylotypes (13 strains) could not be identified with certainty. Multigene phylogenetic analysis and phenotype profiling of four strains with an ITS1 and 2 phylotype similar to Trichoderma strigosum revealed a new sister species of the latter that is described here as Trichoderma strigosellum sp. nov. Sequence similarity searches revealed that this species also occurs in soils of Malaysia and Cameroon, suggesting a pantropical distribution.
Lehtonen, Päivi T; Helander, Marjo; Shahid A Siddiqui; Lehto, Kirsi; Saikkonen, Kari
We studied the effects of fungal endophyte infection of meadow ryegrass (Lolium pratense=Festuca pratensis) on the frequency of the barley yellow dwarf virus (BYDV). The virus is transferred by aphids, which may be deterred by endophyte-origin alkaloids within the plant. In our experiment, we released viruliferous aphid vectors on endophyte-infected and endophyte-free plants in a common garden. The number of aphids and the percentage of BYDV infections were lower in endophyte-infected plants ...
Christian P. KUBICEK; Monika KOMON-ZELAZOWSKA; Irina S. DRUZHININA
Hypocrea/Trichoderma is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immuno-compromised humans and animals, while others can cause damage to cultivated mushroom. With the recent advent of a reliable, BarCode-aided identification system for all known taxa of Trichoderma and Hypocrea, it became now possible to study some of the biological fundamentals of the diversity in this fungal genus in more detail. In this article, we will therefore review recent progress in (1) the understanding of the geographic distribution of individual taxa; (2) mechanisms of speciation leading to development of mushroom diseases and facultative human mycoses; and (3) the possible correlation of specific traits of secondary metabolism and molecular phylogeny.
Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood
Full Text Available Bacterial endophytes are crucial for the survival of many terrestrial plants, but little is known about the presence and importance of bacterial endophytes of marine plants. We conducted a survey of the endophytic bacterial community of the long-living Mediterranean marine angiosperm Posidonia oceanica in surface-sterilized tissues (roots, rhizomes and leaves by DGGE. A total of 26 Posidonia oceanica meadows around the Balearic Islands were sampled, and the band patterns obtained for each meadow were compared for the three sampled tissues. Endophytic bacterial sequences were detected in most of the samples analyzed. A total of 34 OTUs (Operational Taxonomic Units were detected. The main OTUs of endophytic bacteria present in P. oceanica tissues belonged primarily to Proteobacteria (α, γ and δ subclasses and Bacteroidetes. The OTUs found in roots significantly differed from those of rhizomes and leaves. Moreover, some OTUs were found to be associated to each type of tissue. Bipartite network analysis revealed differences in the bacterial endophyte communities present on different islands. The results of this study provide a pioneering step toward the characterization of the endophytic bacterial community associated with tissues of a marine angiosperm and reveal the presence of bacterial endophytes that differed among locations and tissue types.
Chen, Ling; Zhang, Qiao-Yan; Jia, Min; Ming, Qian-Liang; Yue, Wei; Rahman, Khalid; Qin, Lu-Ping; Han, Ting
Plant endophytic fungi have been recognized as an important and novel resource of natural bioactive products, especially in anticancer application. This review mainly deals with the research progress on the production of anticancer compounds by endophytic fungi between 1990 and 2013. Anticancer activity is generally associated with the cytotoxicity of the compounds present in the endophytic fungi. All strains of endophytes producing antitumor chemicals were classified taxonomically and the genera of Pestalotiopsis and Aspergillus as well as the taxol producing endophytes were focused on. Classification of endophytic fungi producing antitumor compounds has received more attention from mycologists, and it can also lead to the discovery of novel compounds with antitumor activity due to phylogenetic relationships. In this review, the structures of the anticancer compounds isolated from the newly reported endophytes between 2010 and 2013 are discussed including strategies for the efficient production of the desired compounds. The purpose of this review is to provide new directions in endophytic fungi research including integrated information relating to its anticancer compounds.
Aschehoug, Erik T; Callaway, Ragan M; Newcombe, George; Tharayil, Nishanth; Chen, Shuyan
Endophytic plant symbionts can have powerful effects on the way their hosts interact with pathogens, competitors, and consumers. The presence of endophytes in plants can alter food webs, community composition and ecosystem processes, suggesting that endophyte-plant symbioses may represent unique forms of extended phenotypes. We tested the impact of the fungal endophyte Alternaria alternata (phylotype CID 120) on the allelopathic effect of the invasive forb Centaurea stoebe when in competition with the North American native bunchgrass Koeleria macrantha in a greenhouse competition experiment. The allelopathic effect of C. stoebe on K. macrantha when infected with the fungal endophyte was more than twice that of endophyte-free C. stoebe. However, this allelopathic effect was a small part of the very large competitive effect of C. stoebe on K. macrantha in all treatments, likely because of the priority effects in our experimental design. To our knowledge, these results are the first experimental evidence for a symbiotic relationship between plants and fungal endophytes affecting allelopathic interactions between competing plants, and thus provide insight into the mechanisms by which fungal endophytes may increase the competitive ability of their hosts.
Langenfeld, Aude; Prado, Soizic; Nay, Bastien; Cruaud, Corine; Lacoste, Sandrine; Bury, Edith; Hachette, François; Hosoya, Tsuyoshi; Dupont, Joëlle
Although endophytes of conifers have been extensively studied, few data are available on Cephalotaxaceae. We examined foliar and stem endophytes of Cephalotaxus harringtonia, within its natural range in Japan and outside its natural range in France to study the effect of geography on endophyte community composition. In Japan, rapidly growing endophytes were dominant and may have masked the real diversity, in comparison to France where most endophytes were growing slowly. Analyses of ITS rDNA revealed 104 different Blast Groups among 554 isolates. Almost no overlap between endophyte assemblages of C. harringtonia from the two countries was observed. It seems that Japanese C. harringtonia trees, which should be well adapted to their native site, would host a specific, endemic endophyte community, while trees that have been introduced recently to a foreign site, in France, should have captured existing cosmopolitan and more generalist taxa. In Japan the majority of xylariaceous taxa, which dominated the communities, were unknown and, although closely related to Asian taxa, may be new to science. Dothideomycetes were more prevalent in France. Locally, urban environment, particularly in Japan, may have introduced some perturbations in the native endophyte community of C. harringtonia, with an abundance of generalist fungi such as Nigrospora and Colletotrichum.
Kaul, Sanjana; Sharma, Tanwi; K Dhar, Manoj
Endophytes, which mostly include bacteria, fungi and actinomycetes, are the endosymbionts that reside asymptomatically in plants for at least a part of their life cycle. They have emerged as a valuable source of novel metabolites, industrially important enzymes and as stress relievers of host plant, but still many aspects of endophytic biology are unknown. Functions of individual endophytes are the result of their continuous and complex interactions with the host plant as well as other members of the host microbiome. Understanding plant microbiomes as a system allows analysis and integration of these complex interactions. Modern genomic studies involving metaomics and comparative studies can prove to be helpful in unraveling the gray areas of endophytism. A deeper knowledge of the mechanism of host infestation and role of endophytes could be exploited to improve the agricultural management in terms of plant growth promotion, biocontrol and bioremediation. Genome sequencing, comparative genomics, microarray, next gen sequencing, metagenomics, metatranscriptomics are some of the techniques that are being used or can be used to unravel plant-endophyte relationship. The modern techniques and approaches need to be explored to study endophytes and their putative role in host plant ecology. This review highlights "omics" tools that can be explored for understanding the role of endophytes in the plant microbiome.
Myriam S. Zawoznik
Full Text Available Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.
Zawoznik, Myriam S; Vázquez, Susana C; Díaz Herrera, Silvana M; Groppa, María D
Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Trichoderma gamsii strain ICC 080... RESIDUES IN FOOD Exemptions From Tolerances § 180.1293 Trichoderma gamsii strain ICC 080; exemption from the requirement of a tolerance. Trichoderma gamsii strain ICC 080 is exempted from the requirement...
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Trichoderma asperellum strain ICC 012... RESIDUES IN FOOD Exemptions From Tolerances § 180.1294 Trichoderma asperellum strain ICC 012; exemption from the requirement of a tolerance. Trichoderma asperellum strain ICC 012 is exempted from...
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Trichoderma harzianum strain T-39... RESIDUES IN FOOD Exemptions From Tolerances § 180.1201 Trichoderma harzianum strain T-39; exemption from the requirement of a tolerance. Trichoderma harzianum strain T-39 is exempt from the requirement of...
Thomas D. Wheelock; Meiyu Shen
Coal beneficiation is achieved by suspending coal fines in a colloidal suspension of microscopic gas bubbles in water under atmospheric conditions to form small agglomerates of the fines adhered by the gas bubbles. The agglomerates are separated, recovered and resuspended in water. Thereafter, the pressure on the suspension is increased above atmospheric to deagglomerate, since the gas bubbles are then re-dissolved in the water. During the deagglomeration step, the mineral matter is dispersed, and when the pressure is released, the coal portion of the deagglomerated gas-saturated water mixture reagglomerates, with the small bubbles now coming out of the solution. The reagglomerate can then be separated to provide purified coal fines without the mineral matter.
Lykkesfeldt, Jens; Poulsen, Henrik Enghusen
of the benefit:harm ratio of antioxidant supplements. We have examined the literature on vitamin C intervention with the intention of drawing a conclusion on its possible beneficial or deleterious effect on health and the result is discouraging. One of several important issues is that vitamin C uptake is tightly...... controlled, resulting in a wide-ranging bioavailability depending on the current vitamin C status. Lack of proper selection criteria dominates the currently available literature. Thus, while supplementation with vitamin C is likely to be without effect for the majority of the Western population due...... to saturation through their normal diet, there could be a large subpopulation with a potential health problem that remains uninvestigated. The present review discusses the relevance of the available literature on vitamin C supplementation and proposes guidelines for future randomised intervention trials....
Anar Janet Rodríguez Cheang
Full Text Available Excessive application of chemical nitrogen fertilisers and pesticides has badly affected the environment. This has led to great interest being shown in studying a crop's native microbial community and its benefit for plants. This paper was thus aimed at characterising sugarcane's endophytic microbial community. 5 sugar cane strains and 50 isolates were used. Gas chromatography was used for measuring nitrogenase activity and the influence of carbon and nitrogen sources and pH on cultures. Indol acetic (IAA production was detected by Dot-Immunobinding and Salkowski's method. These results show that 19 strains and isolates had nitrogenase activity, values ranging from 100 to SOOO/zg/mL; 6 of them produced IAA (values ranging from 1,7 to 2,5 //g/mL: Gluconacetobacter diazotrophicus PAl-5, Gluconacetobacter diazotrophicus 1-05, Gluconacetobacter diazotrophicus 4-02,17,30 and 305. It was demonstrated that culture medium nutrient sources and pH affected the nitrogenase activity of the strains representing the endophytic community. Key words: endophytic community, sugarcane, nitrogenase activity, indolacetic acid.
de Abreu, C S; Figueiredo, J E F; Oliveira, C A; Dos Santos, V L; Gomes, E A; Ribeiro, V P; Barros, B A; Lana, U G P; Marriel, I E
In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.
Margaret Carpenter; Alison Stewart; Hayley Ridgway
@@ Trichoderma species are currently used as biocontrol agents for crop diseases caused by a number of fungal plant pathogens. However, their biocontrol performance in the field can be unreliable and it is likely that more consistent performance could be achieved through knowledge and manipulation of the genes involved. For example, induction of the genes could be optimised for variable environmental and physiological conditions, superior strains could be selected more effectively and novel strains could be created. One method by which Trichoderma species accomplish biocontrol is mycoparasitism. Several genes involved in the mycoparasitic interaction have previously been characterised, however these consist predominantly of those that encode enzymes that degrade fungal cell walls. In the current study subtractive hybridisation was used to target genes expressed when Trichoderma hamatum and the plant pathogen Sclerotinia sclerotiorum were cultured together, subtracting genes expressed when each are grown individually. This experimental design has the potential to yield T.hamatum genes involved in mycoparasitism of S. sclerotiorum, and S. sclerotiorum genes upregulated in host defence. The cDNA fragments yielded by the subtraction were characterised with respect to expression, sequence and species of origin. A number of novel T. hamatum genes which were up-regulated during mycoparasitism were identified.
Full Text Available O presente trabalho visou testar e selecionar isolados selvagens de Trichoderma spp. quanto à capacidade antagônica ao fungo fitopatogênico Verticillium dahliae. Os ensaios in vitro consistiram de testes para avaliar a capacidade hiperparasítica e de antibiose através da produção de metabólitos voláteis e não voláteis. Pela técnica de culturas pareadas, 47 isolados de diversas espécies de Trichoderma foram avaliados e, pelos resultados obtidos, 20 foram selecionados. Através do teste de antibiose, selecionaram-se 7 isolados: T15P e Tal-1 (T. viride, TW6 e CNP311A (T. koningii, CNP17 e TCII (T. harzianum e Tal-10 (T. aureoviride os quais inibiram completamente o crescimento micelial de V. dahliae através da produção de metabólitos. Observações microscópicas demonstraram interações de hifas entre Trichoderma sp. e V. dahliae, tais como: enrolamento, crescimento paralelo de ambos, formação de ganchos.
Svistova, I. D.; Senchakova, T. Yu.
The autecological properties of Trichoderma fungi ecotypes isolated from the leached chernozem of the forest-steppe zone of the European part of Russia have been studied. We were the first who carried out the complex study of the synecological relations of micromycetes of such kinds in a system including the soil, microbial community, and plants, i.e., their relations with soil saprotrophic fungi, bacteria, actinomycetes, plants, and pathogenic fungi. It was shown that the ecological plasticity of the Trichoderma genus in the soil of this zone is determined by its growth rate, the optimum pH and temperature, the biosynthesis of extracellular hydrolytic enzymes, the biological action of mycotoxins, and the ability for parasitism. The efficiency of the introduction of Trichoderma species typical and atypical for the leached chernozem into this soil and their influence on the structure of the microbial community were evaluated. The T. pseudokoningii ecotype, which produces cellulolytic enzymes, is very promising for industrial biotechnology, and the T. harzianum ecotype can be used in soil biotechnology for the biocontrol of chernozem. The addition of a commercial trichodermin preparation into the chernozem damages the structure of its microbial community.
Kusari, Souvik; Singh, Satpal; Jayabaskaran, Chelliah
Taxol® (generic name paclitaxel) represents one of the most clinically valuable natural products known to mankind in the recent past. More than two decades have elapsed since the notable discovery of the first Taxol®-producing endophytic fungus, which was followed by a plethora of reports on other endophytes possessing similar biosynthetic potential. However, industrial-scale Taxol® production using fungal endophytes, although seemingly promising, has not seen the light of the day. In this opinion article, we embark on the current state of knowledge on Taxol® biosynthesis focusing on the chemical ecology of its producers, and ask whether it is actually possible to produce Taxol® using endophyte biotechnology. The key problems that have prevented the exploitation of potent endophytic fungi by industrial bioprocesses for sustained production of Taxol® are discussed.
Weyens, N.; van der Lelie, D.; Taghavi, S.; Vangronsveld, J.
A promising field to exploit plant-endophyte partnerships is the remediation of contaminated soils and (ground) water. Many plant growth promoting endophytes can assist their host plant to overcome contaminant-induced stress responses, thus providing improved plant growth. During phytoremediation of organic contaminants, plants can further benefit from endophytes possessing appropriate degradation pathways and metabolic capabilities, leading to more efficient contaminant degradation and reduction of both phytotoxicity and evapotranspiration of volatile contaminants. For phytoremediation of toxic metals, endophytes possessing a metal-resistance/sequestration system can lower metal phytotoxicity and affect metal translocation to the above-ground plant parts. Furthermore, endophytes that can degrade organic contaminants and deal with or, even better, improve extraction of the metals offer promising ways to improve phytoremediation of mixed pollution.
Full Text Available Endophytes are symptomless fungal or bacterial microorganisms found in almost all living plant species reported so far. They are the plant-associated microbes that form symbiotic association with their host plants by colonizing the internal tissues, which has made them valuable for agriculture as a tool in improving crop performance. Many fungal endophytes produce secondary metabolites such as auxin, gibberellin etc that helps in growth and development of the host plant. Some of these compounds are antibiotics having antifungal, antibacterial and insecticidal properties, which strongly inhibit the growth of other microorganisms, including plant pathogens. This article reviews the endophyte isolated from different plants, mode of endophytic infection and benefits derived by the host plant as a result of endophytism.
Rangjaroen, Chakrapong; Rerkasem, Benjavan; Teaumroong, Neung; Sungthong, Rungroch; Lumyong, Saisamorn
Communities of bacterial endophytes within the rice landraces cultivated in the highlands of northern Thailand were studied using fingerprinting data of 16S rRNA and nifH genes profiling by polymerase chain reaction-denaturing gradient gel electrophoresis. The bacterial communities' richness, diversity index, evenness, and stability were varied depending on the plant tissues, stages of growth, and rice cultivars. These indices for the endophytic diazotrophic bacteria within the landrace rice Bue Wah Bo were significantly the lowest. The endophytic bacteria revealed greater diversity by cluster analysis with seven clusters compared to the endophytic diazotrophic bacteria (three clusters). Principal component analysis suggested that the endophytic bacteria showed that the community structures across the rice landraces had a higher stability than those of the endophytic diazotrophic bacteria. Uncultured bacteria were found dominantly in both bacterial communities, while higher generic varieties were observed in the endophytic diazotrophic bacterial community. These differences in bacterial communities might be influenced either by genetic variation in the rice landraces or the rice cultivation system, where the nitrogen input affects the endophytic diazotrophic bacterial community.
Bu, Ning; Li, Xuemei; Li, Yueying; Ma, Chunyan; Ma, Lianju; Zhang, Chi
Endophyte infected and uninfected seedlings of rice (Oryza sativa L.) were subjected to five different levels of Na(2)CO(3) for 2 weeks. Under both Na(2)CO(3) stress as well as no stress, endophyte-infected plants were higher for above-ground dry weight and shoot length, but lower for root length compared to non-infected controls, and there was no significant difference for below-ground dry weight. Chlorophylls and carotenoid contents, net photosynetic rate, transpiration rate, catalase and peroxidase activities increased, but malondialdehyde content declined in the infected plants compared to non-infected controls under Na(2)CO(3) stress. Compared to non-infected controls, water use efficiency, stomatal conductance, chlorophyll fluorescence parameters (F(v)/F(m), F(v)/F(o)) and superoxide dismutase activity in infected plants increased under high concentrations of Na(2)CO(3) while there was no significant difference under low concentrations of Na(2)CO(3). Endophyte infection was concluded to be beneficial to the growth and antioxidative mechanisms in Oryza sativa under Na(2)CO(3) stress.
Effects of endophyte colonization of Vicia faba (Fabaceae plants on the life-history of leafminer parasitoids Phaedrotoma scabriventris (hymenoptera: braconidae and Diglyphus isaea (hymenoptera: eulophidae.
Komivi S Akutse
Full Text Available Effects of the fungal endophytes Beauveria bassiana (isolates ICIPE 279, G1LU3, S4SU1 and Hypocrea lixii (isolate F3ST1 on the life-history of Phaedrotoma scabriventris and Diglyphus isaea, parasitoids of the pea leafminer Liriomyza huidobrensis, were studied in the laboratory. Parasitoids were allowed to parasitize 2(nd and 3(rd instar L. huidobrensis larvae reared on endophytically-inoculated faba bean, Vicia faba. In the control, parasitoids were reared on non-inoculated host plants. Parasitism, pupation, adult emergence and survival were recorded. No significant difference was observed between the control and the endophyte-inoculated plants in terms of parasitism rates of P. scabriventris (p = 0.68 and D. isaea (p = 0.45 and adult' survival times (p = 0.06. The survival period of the F1 progeny of P. scabriventris was reduced (p<0.0001 in B. bassiana S4SU1 to 28 days as compared to more than 40 days for B. bassiana G1LU3, ICIPE 279 and H. lixii F3ST1. However, no significant difference (p = 0.54 was observed in the survival times of the F1 progeny of D. isaea. This study has demonstrated that together, endophytes and parasitoids have beneficial effects in L. huidobrensis population suppression.
Clay, Keith; Schardl, Christopher
Over the past 20 yr much has been learned about a unique symbiotic interaction between fungal endophytes and grasses. The fungi (Clavicipitaceae, Ascomycota) grow intercellularly and systemically in aboveground plant parts. Vertically transmitted asexual endophytes forming asymptomatic infections of cool-season grasses have been repeatedly derived from sexual species that abort host inflorescences. The phylogenetic distribution of seed-transmitted endophytes is strongly suggestive of cocladogenesis with their hosts. Molecular evidence indicates that many seed-transmitted endophytes are interspecific hybrids. Superinfection may result in hyphal fusion and parasexual recombination. Most endophytes produce one or more alkaloid classes that likely play some role in defending the host plant against pests. Hybridization may have led to the proliferation of alkaloid-production genes among asexual endophytes, favoring hybrids. The ergot alkaloid ergovaline, lolitrems, and lolines are produced by only a single sexual species, Epichloë festucae, but they are common in seed-transmitted endophytes, suggesting that E. festucae contributed genes for their synthesis. Asexual hybrids may also be favored by the counteracting of the accumulation of deleterious mutations (Muller's rachet). Endophyte infection can provide other benefits, such as enhanced drought tolerance, photosynthetic rate, and growth. Estimates of infection frequency have revealed variable levels of infection with especially high prevalence in the subfamily Pooideae. Longitudinal studies suggest that the prevalence of seed-transmitted endophytes can increase rapidly over time. In field experiments, infected tall fescue suppressed other grasses and forbs relative to uninfected fescue and supported lower consumer populations. Unlike other widespread plant/microbial symbioses based on the acquisition of mineral resources, grass/endophyte associations are based primarily on protection of the host from biotic and
Santamaría, Johanna; Bayman, Paul
Plants harbor diverse communities of fungi and other microorganisms. Fungi are known to occur both on plant surfaces (epiphytes) and inside plant tissues (endophytes), but the two communities have rarely been compared. We compared epiphytic and endophytic fungal communities associated with leaves of coffee (Coffea arabica) in Puerto Rico. We asked whether the dominant fungi are the same in both communities, whether endophyte and epiphyte communities are equally diverse, and whether epiphytes and endophytes exhibit similar patterns of spatial heterogeneity among sites. Leaves of naturalized coffee plants were collected from six sites in Puerto Rico. Epiphytic and endophytic fungi were isolated by placing leaf pieces on potato dextrose agar without and with surface sterilization, respectively. A total of 821 colonies were isolated and grouped into 131 morphospecies. The taxonomic affinities of the four most common nonsporulating fungi were determined by sequencing the nuclear ribosomal internal transcribed spacer (ITS) region: two grouped with Xylaria and one each with Botryosphaeria and Guignardia. Of the most common genera, Pestalotia and Botryosphaeria were significantly more common as epiphytes; Colletotrichum, Xylaria, and Guignardia were significantly more common as endophytes. Suprisingly, more morphospecies occurred as endophytes than as epiphytes. Differences among sites in number of fungi per plant were significant. Thus epiphytic and endophytic communities differed greatly on a single leaf, despite living only millimeters apart, and both communities differed from site to site. Significant correlations between occurrence of fungal morphospecies suggested that fungi may have positive or negative effects on their neighbors. This is the first quantitative comparison of epiphytic and endophytic fungal floras in any plant, and the first to examine endophytic fungi or epiphytic fungi in leaves of coffee, one of the world's most valuable crops.
Full Text Available Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in T. harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by i enhanced growth, ii increased carbon and nitrogen levels and iii a
Wagner, Karl; Apostolakis, Antonios; Daliakopoulos, Ioannis; Tsanis, Ioannis
Soil salinity is a major soil degradation threat, especially for arid coastal environments where it hinders agricultural production and soil health. Protected horticultural crops in the Mediterranean region, typically under deficit irrigation and intensive cultivation practices, have to cope with increasing irrigation water and soil salinization. This study quantifies the beneficial effects of the Trichoderma harzianum (TH) on the sustainable production of Solanum lycopersicum (tomato), a major greenhouse crop of the RECARE project Case Study in Greece, the semi-arid coastal Timpaki basin in south-central Crete. 20 vigorous 20-day-old Solanum lycopersicum L. cv Elpida seedlings are treated with TH fungi (T) or without (N) and transplanted into 35 L pots under greenhouse conditions. Use of local planting soil with initial Electrical Conductivity (ECe) 1.8 dS m-1 and local cultivation practices aim to simulate the prevailing conditions at the Case Study. In order to simulate seawater intrusion affected irrigation, plants are drip irrigated with two NaCl treatments: slightly (S) saline (ECw = 1.1 dS m-1) and moderately (M) saline water (ECw = 3.5 dS m-1), resulting to very high and excessively high ECe, respectively. Preliminary analysis of below and aboveground biomass, soil quality, salinity, and biodiversity indicators, suggest that TH pre-inoculation of tomato plants at both S and M treatments improve yield, soil biodiversity and overall soil health.
Steyaert, Johanna; Hicks, Emily; Kandula, Janaki; Kandula, Diwakar; Alizadeh, Hossein; Braithwaite, Mark; Yardley, Jessica; Mendoza-Mendoza, Artemio
Members of the genus Trichoderma comprise the majority of commercial fungal biocontrol agents of plant diseases. As such, there is a wealth of information available on the analysis of their biocontrol potential and the mechanisms behind their superior abilities. This chapter aims to summarize the most common methods utilized within a Trichoderma biocontrol program for assessing the biological properties of individual strains.
Festuccia, M; Giaccone, L; Gay, F; Brunello, L; Maffini, E; Ferrando, F; Talamo, E; Boccadoro, M; Serra, R; Barbui, A; Bruno, B
We present a case of Trichoderma fungemia with pulmonary involvement in a multiple myeloma patient, who was severely immunocompromised and heavily treated with high-dose melphalan, and underwent autologous hematopoietic cell transplantation. This is the first report, to our knowledge, of proven Trichoderma fungemia, defined by published criteria, successfully treated with voriconazole.
Sandheep, A R; Asok, A K; Jisha, M S
This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.
... incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the... Trichoderma longibrachiatum. 184.1250 Section 184.1250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase...
Full Text Available Fungi of the genus Trichoderma are used as biocontrol agents against several plant pathogenic fungi like Rhizoctonia spp., Pythium spp., Botrytis cinerea and Fusarium spp. which cause both soil-borne and leaf- or flower-borne diseases of agricultural plants. Plant disease control by Trichoderma is based on complex interactions between Trichoderma, the plant pathogen and the plant. Until now, two main components of biocontrol have been identified: direct activity of Trichoderma against the plant pathogen by mycoparasitism and induced systemic resistance in plants. As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognised by Trichoderma and provoke transcription of mycoparasitism-related genes.In the last few years examination of signalling pathways underlying Trichoderma biocontrol started and it was shown that heterotrimeric G-proteins and mitogen-activated protein (MAP kinases affected biocontrol-relevant processes such as the production of hydrolytic enzymes and antifungal metabolites and the formation of infection structures. MAPK signalling was also found to be involved in induction of plant systemic resistance in Trichoderma virens and in the hyperosmotic stress response in Trichoderma harzianum. Analyses of the function of components of the cAMP pathway during Trichoderma biocontrol revealed that mycoparasitism-associated coiling and chitinase production as well as secondary metabolism are affected by the internal cAMP level; in addition, a cross talk between regulation of light responses and the cAMP signalling pathway was found in Trichoderma atroviride.
Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L
The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.
Full Text Available Endophytic microorganisms, defined as fungi or bacteria that colonize the interior of plants without causing any immediate negative effects or damages, have reciprocal relationships with host plants. In some cases their presence is beneficial to the host due to the synthesis of bioactive compounds, among which several alcohols, esters, ketones and others that may react with other compounds and may be lethal to pathogenic microorganisms. Diaporthe helianthi (Phomopsis helianthi in its anamorphic phase is available worldwide, especially in Europe, Asia and America. Isolated in Europe as an agent of the sunflower stem cancer, it has also been endophytically isolated from tropical and temperate plants. A D. helianthi strain isolated from Luehea divaricata has been employed in current research. An investigation of the secondary metabolite from D. helianthi by CC and NMR of ¹H and 13C yielded the separation of 10 fractions and the identification of the phenolic compound 2(-4 hydroxyphenyl-ethanol (Tyrosol. Its antimicrobial reaction was tested and the ensuing antagonistic effects on the human pathogenic bacteria Enterococcus hirae, Escherichia coli, Micrococcus luteus, Salmonella typhi, Staphylococcus aureus, phytopathogenic Xanthomonas asc. phaseoli and phytopathogenic fungi were demonstrated. Results show that bioactive compounds and Tyrosol produced by D. helianthi have a biotechnological potential.
Yuemin Zhao; Xuliang Yang; Zhenfu Luo; Chenlong Duan; Shulei Song
China’s energy supply heavily relies on coal and China’s coal resource and water resource has a reverse distribution. The problem of water shortages restricts the applications of wet coal beneficiation technologies in drought regions. The present situation highlights the significance and urgency of developing dry beneficiation technologies of coal. Besides, other countries that produce large amounts of coal also encounter serious problem of lack of water for coal beneficiation, such as American, Australia, Canada, South Africa, Turkey and India. Thus, dry coal beneficiation becomes the research hot-points in the field of coal cleaning worldwide in recent years. This paper systematically reviewed the promising research efforts on dry coal beneficiation reported in literature in last 5 years and discussed the progress in developments of dry coal beneficiation worldwide. Finally, we also elaborated the prospects and the challenges of the development of dry coal beneficiation.
Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo
Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes.
Monnanda Somaiah Nalini
Full Text Available Endophytes constitute an important component of microbial diversity, and in the present investigation, seven plant species with rich ethnobotanical uses representing six families were analyzed for the presence of endophytic fungi from their natural habitats during monsoon (May/June and winter (November/December seasons of 2007. Fungal endophytes were isolated from healthy plant parts such as stem, root, rhizome, and inflorescence employing standard isolation methods. One thousand five hundred and twenty-nine fungal isolates were obtained from 5200 fragments. Stem fragments harbored more endophytes (80.37% than roots (19.22%. 31 fungal taxa comprised of coelomycetes (65%, hyphomycetes (32%, and ascomycetes (3%. Fusarium, Acremonium, Colletotrichum, Chaetomium, Myrothecium, Phomopsis, and Pestalotiopsis spp. were commonly isolated. Diversity indices differed significantly between the seasons (P<0.001. Species richness was greater for monsoon isolations than winter. Host specificity was observed for few fungal endophytes. UPGMA cluster analysis grouped the endophytes into distinct clusters on the basis of genetic distance. This study is the first report on the diversity and host-specificity of endophytic fungal taxa were from the semi evergreen forest type in Talacauvery subcluster of Western Ghats.
Santos, Silvana Gomes Dos; Silva, Paula Renata Alves da; Garcia, Andres Calderin; Zilli, Jerri Édson; Berbara, Ricardo Luis Louro
Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.
Lemons, Alisha; Clay, Keith; Rudgers, Jennifer A
Mutualisms can strongly affect the structure of communities, but their influence on ecosystem processes is not well resolved. Here we show that a plant-microbial mutualism affects the rate of leaf litter decomposition using the widespread interaction between tall fescue grass (Lolium arundinaceum) and the fungal endophyte Neotyphodium coenophialum. In grasses, fungal endophytes live symbiotically in the aboveground tissues, where the fungi gain protection and nutrients from their host and often protect host plants from biotic and abiotic stress. In a field experiment, decomposition rate depended on a complex interaction between the litter source (collected from endophyte-infected or endophyte-free plots), the decomposition microenvironment (endophyte-infected or endophyte-free plots), and the presence of mesoinvertebrates (manipulated by the mesh size of litter bags). Over all treatments, decomposition was slower for endophyte-infected fescue litter than for endophyte-free litter. When mesoinvertebrates were excluded using fine mesh and litter was placed in a microenvironment with the endophyte, the difference between endophyte-infected and endophyte-free litter was strongest. In the presence of mesoinvertebrates, endophyte-infected litter decomposed faster in microenvironments with the endophyte than in microenvironments lacking the endophyte, suggesting that plots differ in the detritivore assemblage. Indeed, the presence of the endophyte in plots shifted the composition of Collembola, with more Hypogastruridae in the presence of the endophyte and more Isotomidae in endophyte-free plots. In a separate outdoor pot experiment, we did not find strong effects of the litter source or the soil microbial/microinvertebrate community on decomposition, which may reflect differences between pot and field conditions or other differences in methodology. Our work is among the first to demonstrate an effect of plant-endophyte mutualisms on ecosystem processes under field
李向楠; 周稚凡; 刘风路; 李靖
In this study, the endophytic fungi were isolated and purified from the seeds of T.yunnanensis collected from Weixi County, Yunnan Province. The morphology of the endophytic fungi was identified,and antimicrobial activity was screened. By fungal separation and purification technology, endophytic fungi were isolated initially from the seeds of T.yunnanensis. Morphological analyses of endophytic fungi were conducted by microscopic observation of sporulation structures, and antibacterial activities were screened by filter paper method. Fifty endophytic fungi were isolated and purified. Among them, 13 belonged to Phomopsis, 7 Fusarium, 5 Anthrax, 4 Paecilomyces, 1 Alternaria, 1 Trichoderma, and 19 without spores. Antimicrobial results showed that crude extracts of endophytic fungi had broader inhibitory effects on ten important plant pathogenic fungi. Z41 and Z43 exhibited the best antimicrobial activities.%对采自云南省维西县的云南榧（Torreya yunnanensis）种子的内生真菌进行分离纯化和初步形态学鉴定，同时对内生真菌的抑菌活性进行筛选。通过真菌分离纯化技术对云南榧种子的内生真菌进行分离纯化，通过显微镜观察产孢结构进行初步形态学分析，并通过滤纸片法对内生真菌的抑菌活性进行筛选。从云南榧种子中共分离纯化得到50株内生真菌，其中拟茎点霉属13株，镰孢霉属7株，炭疽霉属5株，拟青霉属4株，链格孢属1株，木霉属1株，无孢菌群19株。抑菌活性显示云南榧种子内生真菌具有广泛的抑菌活性，其中菌株Z41与Z43对10种植物病原真菌具有广谱抗性。
Kueppers, L. M.; Moyes, A. B.; Frank, C.; Pett-Ridge, J.; Carper, D.; Vandehey, N.; O'Neil, J.; Dekas, A.
Endophytic microorganisms - bacteria and fungi that live inside healthy plant tissue - are a relatively unexplored source of functional diversity in natural ecosystems. Prior to modern sequencing technology, detecting uncultured endophytic bacteria and assessing their putative functions was challenging. However, recent work has revealed a remarkable diversity of as yet non-culturable endophytic taxa and is beginning to identify functional roles within plant microbiomes. We recently examined bacterial communities in the foliage of a long-lived, high-elevation conifer species, limber pine (Pinus flexilis), and discovered a community strongly dominated by acetic acid bacteria (Acetobacteraceae), with several taxa closely related to known nitrogen fixers. Given limber pine's status as a pioneer species that is able to grow in low fertility soils, we hypothesized that this bacterial community has a potential functional role in fixing atmospheric nitrogen, providing a source of this limiting nutrient to the host tree. We used the radioisotope 13N2 to confirm that N2 rapidly diffuses into pine needles, where it could potentially be fixed. With an acetylene reduction assay we confirmed nitrogenase enzyme activity inside excised twigs 4 times over a growing season, and estimate potential rates of N2 fixation at 0.1 nmol N2 g needle-1 hr-1. Scaled to the stand level, this N input could be on the order of ~20 mg N m-2 d-1 over a growing season. While these rates are low, the long lifespan of individual trees (~1000 years) makes them biologically meaningful. Still, measured rates of acetylene reduction and bulk 15N2 incorporation are quite variable in space and time. Much work remains to better characterize the plant-microbial interactions in this system, including the rates of nitrogen fixation and their variability over the growing season, across edaphic conditions, among host species, and through plant development; and to determine which community members are responsible
Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki
Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production.
LI Pei-jun; JING De-bing; ZHOU Qi-xing; ZHANG Chun-gui
To exploit peashrub resources in Ordos as fodders, it is very crucial to realize industrial production of cheap cellulase of high activity by optimizing culture technology, especially culture substrate. In this study, a new prescription experiment based on uniform design ideal was invented and successfully applied in the solid fermentation of Trichoderma koningii F244, which being performed with two different temperature degrees. The activities of FPA, cotton lyase, CMCase and β-glucosidase were assayed and then mathematical models of enzymatic activities, which were figured out by Unconstraint Mathematical Programming, were developed by Multivariate Regression Program of SPSS10.0. Enzymatic activities of optimized substrate prescriptions corresponding to mathematical models were forecasted to determine an ideal substrate prescription. It is revealed that in solid fermentation, Tween80 has negative effect on cellulase production. Furthermore, the ideal prescription for cellulase complex production by Trichoderma koningii F244 was straw powder 16.9%,wheat bran 26.5%, (NH4)2SO4 9.5% and water 47.1%, whose corresponding cellulase activity was expected to be at the same high level with that of Trichoderma reesei Q9414 on its own recommended substrate. Especially, goats mainly fed on peashrub tissues mixed with cellulase complex of this prescription and culture technology, got an incremental ratio of 0.3 kg/d, which brought a very promising feeding prospect for local peashrub resource. By populization of this cellulase complex, it can integrate living standard, economic construction of local residents into vegetational restoration tightly and thus this paper will be very meaningful to be use for reference for western China like Ordos to realize its sustainable development of economy, society and environment.
Abd El-Baki, G K; Mostafa, Doaa
The interaction between sodium chloride and Trichoderma harzianum (T24) on growth parameters, ion contents, MDA content, proline, soluble proteins as well as SDS page protein profile were studied in Vicia faba Giza 429. A sharp reduction was found in fresh and dry mass of shoots and roots with increasing salinity. Trichoderma treatments promoted the growth criteria as compared with corresponding salinized plants. The water content and leaf area exhibited a marked decrease with increasing salinity. Trichoderma treatments induced a progressive increase in both parameters. Both proline and MDA contents were increased progressively as the salinity rose in the soil. Trichoderma treatments considerably retarded the accumulation of both parameters in shoots and roots. Both Na+ and K+ concentration increased in both organs by enhancing salinity levels. The treatment with Trichoderma harzianum enhanced the accumulation of both ions. Exposure of plants to different concentrations of salinity, or others treated with Trichoderma harzianum produced marked changes in their protein pattern. Three types of alterations were observed: the synthesis of certain proteins declined significantly, specific synthesis of certain other proteins were markedly observed and synthesis of a set specific protein was induced de novo in plant treated with Trichoderma harzianum.
Sarocco, Sabrina; Lübeck, Mette; Vannacci, Giovanni
isolates in a natural pot mix in order to select potential fungal antagonists to be employed in the biocontrol of Rhizoctonia solani damping-off of radish, and 2) to verify the hypothesis that competition for a food base plays a role in reducing pathogen activity. Fifteen Trichoderma spp., selected among...... inoculation procedures were employed. Four potential biocontrol agents, all identified as T. harzianum according to the ITS sequences, were selected according to their ability of reducing radish damping off, and were employed in a Competitive Saprophytic Ability (CSA) test, in order to investigate the role...
Tukhbatova, R I; Fattakhova, A N; Alimova, F K
Melanoma is one of the most malignant tumors, which leaves no chance of survival in the case of the "bang". There are various ways to treat tumors, however, recently in the field of cancer research, there are studies in which fungal metabolites have been used as antitumor agents. In this study we examined the effect of the culture fluid of the fungus Trichoderma asperellum 302 on the growth and development of melanoma B 16. We have shown that these culture fluid has anticancer properties, causing destruction of tumor tissue. Obtained data open new possibilities and prospects for the use of active substances derived from fungi in the complex therapy of cancer.
Full Text Available Background and objectives: Silymarin is a unique flavonoid complex with documented hepatoprotective properties. Silybum marianum hairy root culture as a source for producing silymarin has been an important strategy for study the cell signaling pathway. In the present investigation Trichoderma strains- Silybum marianum hairy root cultures interactions have been studied. Methods: The effects of two Trichoderma Strains (KHB and G46-7 (0, 0.5, 1, 2 and 4 mg/ 50 mL culture in 6 different exposure times (0, 24, 48, 72, 96 and 120 h have been investigated on flavonolignans production. The flavonolignans were analyzed by High Performance Liquid Chromatography method. Cell signaling pathway was evaluated by determination of H2O2 content, peroxidase and ascorbate peroxidase activities. Results:The elicitation effects of two Trichoderma Strains (KHB and G46-7 were examined on flavonolignans accumulation and the activation of cell defense system in S. marianum hairy root cultures. The results indicated that the highest silymarin accumulation (0.45 and 0.33 mg/g DW was obtained in media elicited with 0.5 mg/50 mL cultures of T. harzianum Strains (KHB and G46-3, respectively after 120 h. Feeding time experiments indicated that a significant higher content of silymarin production was achieved after 120 and 72 h in media treated with 0.5 mg/50 mL cultures of KHB and G46-3, respectively. Our results showed that S. marianum treated by KHB strain, increased taxifolin, silychristin, isosilybin and silydianin productions significantly. The H2O2 content in the control hairy root cultures remained lower than the treated cultures. There was significant enhancement in both peroxidase and ascorbate peroxidase activities in treated hairy roots reaching a peak after 72 h. Conclusion: These findings suggested that some Trichoderma strains are positive elicitors for promoting silymarin accumulation in S. marianum hairy root cultures. The results also suggested the presence
Li S; Bramley P M; Smith J; Cannon P F
@@ A series of highly taxonomically diverse Trichoderma strains were investigated using proteomic approaches, to investigate the utility of protein profiles as taxonomic markers and to identify proteins of potential economic importance. Initial studies have focused on a comparison of single strains of T.aureoviride, T. saturnisporum, T. polysporum, T. longbrachiatum and T. spirale, along with two strains of T. harzianum. All seven strains were grown in synthetic medium supplemented with 2 % (w/v) glycerol, to maximize the diversity of extracellular protein production. Samples of secreted protein were separated by 2D gel electrophoresis and will be characterized by MALDI-TOF peptide fingerprinting.
Kusari, Parijat; Kusari, Souvik; Spiteller, Michael; Kayser, Oliver
Radula marginata and Cannabis sativa L. are two phylogenetically unrelated plant species containing structurally similar secondary metabolites like cannabinoids. The major objective of our work was the isolation, identification, biocontrol efficacies, biofilm forming potential and anti-biofilm ability of endophytic microbial community of the liverwort R. marginata, as compared to bacterial endophytic isolates harbored in C. sativa plants. A total of 15 endophytic fungal and 4 endophytic bacterial isolates were identified, including the presence of a bacterial endosymbiont within an endophytic fungal isolate. The endosymbiont was visible only when the fungus containing it was challenged with two phytopathogens Botrytis cinerea and Trichothecium roseum, highlighting a tripartite microbe-microbe interaction and biocontrol potency of endophytes under biotic stress. We also observed sixteen types of endophytic fungal-pathogen and twelve types of endophytic bacterial-pathogen interactions coupled to varying degree of growth inhibitions of either the pathogen or endophyte or both. This showed the magnitude of biocontrol efficacies of endophytes in aiding plant fitness benefits under different media (environmental) conditions. Additionally, it was ecologically noteworthy to find the presence of similar endophytic bacterial genera in both Radula and Cannabis plants, which exhibited similar functional traits like biofilm formation and general anti-biofilm activities. Thus far, our work underlines the biocontrol potency and defensive functional traits (in terms of antagonism and biofilm formation) of endophytes harbored in liverwort R. marginata as compared to the endophytic community of phylogenetically unrelated but phytochemically similar plant C. sativa.
Aerts, R; De Schutter, B; Rombouts, L
In the Flemish horticulture Pythium spp. is an important pathogen of tomato plants (Lycopersicon esculenthum) in soilless growing media. Therefore some experiments were conducted to evaluate the possibility of decreasing the damage caused by Pythium spp. by Trichoderma spp. In a tray with several growing media, a suspension of Trichoderma conidia (10(6)/ml growing medium) was applied two weeks before sowing. On some objects, a compost extract (Biostimulus) was added. The growing media used in the experiment were rockwool, recycled rockwool and recycled coconut fibre. After sowing, the trays were covered with perlite. Three isolates of Trichoderma spp.: T. asperellum (Biofungus), T. harzianum (Tri 003) and Trichoderma sp. (KHK) and two isolates of Pythium spp.: P. ultimum (MUCL) en P. aphanidermatum (HRI, UK) were used. Propamocarb was used as a chemical standard. The use of coconut fibre growing medium resulted in a higher percentage (36%) of germination than the rockwool media when only Pythium spp. was used. The presence of the spontaneous developing microflora in the coconut fibre medium gave probably also a suppression of Pythium spp. For that reason the results of the suppression by Trichoderma spp. are not easy to explain and very variable on the different objects. Pythium ultimum was more suppressed than P. aphanidermatum on all the growing media and the application of all the Trichoderma isolates increased the germination percentage of tomato seeds. T. asperellum (Biofungus) gave on rockwool also a good result for the suppression of P. aphanidermatum (increasing of germination with 48%). This effect was comparable with the propamocarb treatment (48%). T. harzianum (Tri 003) gave a small suppression (22%) and Trichoderma sp. (KHK) gave almost no suppression of P. aphanidermatum (7%). When less Trichoderma conidia were applied the germination percentage decreased. The adding of a compost extract (Biostimulus) had no influence on the results. This experiment
李广记; 陈捷; 刘铜; 刘力行
在华东地区木霉菌资源调查中,利用内转录间隔区(ITS)序列分析和形态学鉴定方法,对从土壤中分离到的木霉菌进行鉴定,发现一个中国新纪录种,即拟康宁木霉.Trichoderma koningiopsis/Hypocrea koningiopsis Samuels,C.Suarez & H.C.Evans sp.nov..该种典型的形态特征是在PDA以及CMD(玉米粉琼脂)上有瓶梗层出现象,而在MA(麦芽提取物)培养基上没有此特征.
Ding, Xiaowei; Liu, Kaihui; Deng, Baiwan; Chen, Wenqiang; Li, Wenjun; Liu, Feihu
In this study, a total of 161 endophytic fungal isolates from Camptotheca acuminata were obtained and classified to 16 taxa according to morphological and molecular analysis. These taxa were composed of 2 frequent genera (Botryosphaeria and Fusarium) and 14 infrequent groups such as Xylaria, Diaporthe, Rhizopus, Epicoccum, and Preussia, demonstrating that fungal endophytes in C. acuminata were highly abundant and diverse. Antimicrobial activity screening using filter-paper diffusion method showed that 47.6 % of the tested isolates had antimicrobial activity against at least one of the test microorganisms. Screening of fungal endophyte-derived camptothecin analogues by TLC and LC-MS/MS³ demonstrated that a strain Botryosphaeria dothidea, X-4 could produce 9-methoxycamptothecin (9-MCPT) when cultured in Sabouraud's dextrose broth for 12 days under shake flask and bench-scale fermention conditions. This work showed that the fungal endophytes from C. acuminata could be an alternative source for the production of 9-MCPT and other natural antimicrobial compounds.
Ravindran, C.; Naveenan, T.; Varatharajan, G.R.; Rajasabapathy, R.; Meena, R.M.
The manner in which fungal endophytes activate host stress response systems is unknown; the occurrence of additional mechanisms involved in symbiotically-conferred stress tolerance in mangrove plants (the primary producers of estuarine food chain...
Zgadzaj, Rafal Lukasz
colonisation of below-ground plant organs. It focused on bacterial endophyte, Rhizobium KAW12, colonisation of spontaneously formed nodules in snf1 mutants and symbiotic signalling mutants in a snf1 background. Additionally, participation of genes required for rhizobial accomodation during endophytic invasion...... was tested by coinoculation experiments with Rhizobium KAW12 and nodule inducing strains or their symbiotically deficient mutants. Such approaches allowed to identify genes possibly involved in host-endophyte recognition. Additionally, bacterial mutants used in these screenings pointed towards...... populations depending on their genotype. Additionally, analysis of Lotus defence response genes was performed after inoculation with epiphytic and endophytic strains of Rhizobium, indicating only minimal differences in their perception by the host....
Full Text Available This is a first part of work devoted highland rush endophytes: Penicillium expansum, Cladosporium oxysporum, Arthrinium state of Apiospora montagnei and Aureobasidium pullulans. The basidiomycete strain, possibly Lagarobasidium detriticum was also isolated.
Ihrmark, Katarina; Asmail, Nashwan; Ubhayasekera, Wimal;
Certain species of the fungal genus Trichoderma are potent mycoparasites and are used for biological control of fungal diseases on agricultural crops. In Trichoderma, whole-genome sequencing reveal between 20 and 36 different genes encoding chitinases, hydrolytic enzymes that are involved in the ...... clades are observed. These observations show that Trichoderma chitinases chi18-13 and chi18-15 evolve in a manner consistent with rapid co-evolutionary interactions and identifies putative target regions involved in determining substrate-specificity....
Li, Chong-Wei; Song, Rui-Qing; Yang, Li-Bin; Deng, Xun
Trichoderma strain T-33 has been demonstrated to have inhibitory effect on the fungus species Cytospora chrysosperma. Here, an active antifungal compound was obtained from Trichoderma strain T-33 extract via combined separation technologies, including organic solvent extraction, liquid chromatography, and thin-layer chromatography. The purified compound was further characterized by advanced analytical technologies to elucidate its chemical structure. Results indicated that the active antifungal compound in Trichoderma strain T-33 extract is 2,5- cyclohexadiene-1,4-dione-2,6-bis (1,1-dimethylethyl).
ZHANG Jing-ze; TU Yan-la
@@ Three strains of Trichoderma spp. TVll2, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou of China. However, it is unclear if there are the antagonism and mycoparasitism of the Trichoderma strains tested against the mycelial growth of R. solani . The objective of this research was to evaluate the ability of the Trichoderma strains to inhibit the mycelial growth of R. solani in vitro .
Guarro, J; Antolín-Ayala, M I; Gené, J; Gutiérrez-Calzada, J; Nieves-Díez, C; Ortoneda, M
We describe the second known case of human infection by Trichoderma harzianum. A disseminated fungal infection was detected in the postmortem examination of a renal transplant recipient and confirmed in culture. The only other reported infection by this fungus caused peritonitis in a diabetic patient. The in vitro antifungal susceptibilities of the clinical strain and three other strains of Trichoderma species to six antifungal drugs are provided. This case illustrates the widening spectrum of opportunistic Trichoderma spp. in immunocompromised patients and emphasizes the problems in diagnosing invasive fungal diseases.
Hidayat Hussain; Siegfried Draeger; Barbara Schulz; Karsten Krohn; Ines Kock; Ahmed Al-Harrasi; Ahmed Al-Rawahi; Ghulam Abbas; Ivan R Green; Afzal Shah; Amin Badshah; Muhammad Saleem
Objective:To evaluate the antimicrobial potential of different extracts of the endophytic fungus Phomasp. and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using theAgarWellDiffusionMethod. Four compounds were purified using column chromatography and their structures were assigned using1H and13CNMR spectra,DEPT,2DCOSY,HMQC andHMBC experiments.Results:The ethyl acetate fraction ofPhomasp. showed good antifungal, antibacterial, and algicidal properties.One new dihydrofuran derivative, named phomafuranol(1), together with three known compounds, phomalacton(2),(3R)-5-hydroxymellein(3) and emodin(4) were isolated from the ethyl acetate fraction ofPhomasp.Preliminary studies indicated that phomalacton(2) displayed strong antibacterial, good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein (3) and emodin(4) showed good antifungal, antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungusPhomasp. and isolated compounds clearly demonstrate thatPhomasp. and its active compounds represent a great potential for the food, cosmetic and pharmaceutical industries.
Itamar Soares de Melo
Full Text Available Rhizoctonia solani causes serious diseases in a wide range of plant species. The fungus Trichoderma has been shown to be particularly effective in the control of the pathogen. Thus, this research was carried out to screen fourteen Trichoderma strains against R. solani in vitro. All strains tested inhibited the growth of R. solani. Three T. koningii strains produced toxic metabolites with strong activity against R. solani, inhibiting the mycelial growth by 79%. T. harzianum, Th-9 reduced the viability of sclerotia of R. solani by 81.8% and T. koningii, TK-5 reduced by 53%. Electron microscopic observations revealed that all T. harzianum strains interacted with R. solani. Th-9 grew toward and coiled around the host cells, penetrating and destroying the hyphae. Penetration of host cells was apparently accomplished by mechanical activity.Rhizoctonia solani é um dos mais destrutivos patógenos de plantas cultivadas. Métodos alternativos de controle têm sido empregados com sucesso, particularmente, utilizando-se o fungo Trichoderma. Este trabalho visou, portanto, selecionar linhagens efetivas desse micoparasita contra o patógeno. Onze linhagens de T. harzianum e três de T. koningii foram testadas in vitro com relação ao parasitismo de hifas e de escleródios e produção de metabólitos tóxicos. Todas as linhagens de Trichoderma spp. inibiram o crescimento miceliano de R. solani e as três linhagens de T. koningii produziram potentes antibióticos, que inibiram mais de 79% o crescimento do patógeno. Uma linhagem de T. harzianum, Th-9, reduziu a viabilidade dos escleródios em 81,8% e uma de T. koningii em 53%. Microscopia eletrônica de varredura revelou que todas as linhagens de T. harzianum parasitaram R. solani enquanto nenhuma linhagem de T. koningii interagiu com R. solani, possivelmente, devido à forte inibição causada pelos metabólitos que impediu o contato entre os dois fungos. T. harzianum, Th-9, cresceu ao redor, penetrou e
Rajala, Tiina; Velmala, Sannakajsa M; Tuomivirta, Tero; Haapanen, Matti; Müller, Michael; Pennanen, Taina
Endophytic fungi show no symptoms of their presence but can influence the performance and vitality of host trees. The potential use of endophytes to indicate vitality has been previously realized, but a standard protocol has yet to be developed due to an incomplete understanding of the factors that regulate endophyte communities. Using a culture-free molecular approach, we examined the extent to which host genotype influences the abundance, species richness, and community composition of endophytic fungi in Norway spruce needles. Briefly, total DNA was extracted from the surface-sterilized needles of 30 clones grown in a nursery field and the copy number of the fungal internal transcribed spacer (ITS) region of ribosomal DNA was estimated by quantitative PCR. Fungal species richness and community composition were determined by denaturing gradient gel electrophoresis and DNA sequencing. We found that community structure and ITS copy number varied among spruce clones, whereas species richness did not. Host traits interacting with endophyte communities included needle surface area and the location of cuttings in the experimental area. Although Lophodermium piceae is considered the dominant needle endophyte of Norway spruce, we detected this species in only 33% of samples. The most frequently observed fungus (66%) was the potentially pathogenic Phoma herbarum. Interestingly, ITS copy number of endophytic fungi correlated negatively with the richness of ectomycorrhizal fungi and thus potential interactions between fungal communities and their influence on the host tree are discussed. Our results suggest that in addition to environmental factors, endophyte communities of spruce needles are determined by host tree identity and needle surface area.
The fungal endophytes associated with grasses are the fundamental reason for the basic successes of several pasture grasses, notable tall fescues, and perennial ryegrass. Tall fescue and perennial ryegrass fungal endophytes, Neotyphodium coenophialum and N. lolii, respectively, and their relatives ...
Tall fescue (Schedonorus arundinaceous (Schreb.)) is often infected with a common toxic fungal endophyte (Neotyphodium coenophialum) capable of producing alkaloids that affect grazing animal health, insect herbivory, plant production, and litter decomposition. The strength of these endophyte-associa...
Hardoim, Pablo R; van Overbeek, Leo S; Elsas, Jan Dirk van
Bacterial endophytes live inside plants for at least part of their life cycle. Studies of the interaction of endophytes with their host plants and their function within their hosts are important to address the ecological relevance of endophytes. The modulation of ethylene levels in plants by bacterially produced 1-aminocyclopropane-1-carboxylate deaminase is a key trait that enables interference with the physiology of the host plant. Endophytes with this capacity might profit from association with the plant, because colonization is enhanced. In turn, host plants benefit by stress reduction and increased root growth. This mechanism leads to the concept of 'competent' endophytes, defined as endophytes that are equipped with genes important for maintenance of plant-endophyte associations. The ecological role of these endophytes and their relevance for plant growth are discussed here.
The fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae were investigated to determine if endophytic colonization could be achieved in cassava. An inoculation method based on drenching the soil around cassava stems using conidial suspensions resulted in endophytic colonization of ca...
Santosh Kumar Singh
Full Text Available Fungal endophytes are ubiquitously reported from the living tissues of healthy plant parts from every host studied so far. These microbes attributed significantly in upraising the caliber of the host to counteract against the different stresses and herbivores, and also some times to improve the host fitness. This study presenting here the endophytic mycoflora of Jatropha curcus, which remain less explored. A total of eighteen species of fungi were isolated from leaf, stem, and roots of Jatropha curcus. The root was heavily colonized by the genera like Alternaria, Cladosporium, and Aspergillus spp. The leaf tissues however showed somewhat greater diversity of endophytic colonization. Drechslera, Curvularia, Bipolaris, Alternaria, and Aspergillus sp. were dominant in to the leaf tissues with strong presence of an unidentified genus. The species richness as well as frequency of colonization of endophytic fungi was more pronounced in the leaf tissues rather than the root and stem. This study reaffirms the fact that endophytes are host and tissues specific. In this regard, the endophytic fungi received in this study, may represent a unique source of one or more of the interesting and useful bioactive compounds similar to those of vinca alkaloid group.
Lundberg, Derek; Woyke, Tanja; Tringe, Susannah; Dangl, Jeff
Land plants grow in association with microbial communities both on their surfaces and inside the plant (endophytes). The relationships between microbes and their host can vary from pathogenic to mutualistic. Colonization of the endophyte compartment occurs in the presence of a sophisticated plant immune system, implying finely tuned discrimination of pathogens from mutualists and commensals. Despite the importance of the microbiome to the plant, relatively little is known about the specific interactions between plants and microbes, especially in the case of endophytes. The vast majority of microbes have not been grown in the lab, and thus one of the few ways of studying them is by examining their DNA. Although metagenomics is a powerful tool for examining microbial communities, its application to endophyte samples is technically difficult due to the presence of large amounts of host plant DNA in the sample. One method to address these difficulties is single-cell genomics where a single microbial cell is isolated from a sample, lysed, and its genome amplified by multiple displacement amplification (MDA) to produce enough DNA for genome sequencing. This produces a single-cell amplified genome (SAG). We have applied this technology to study the endophytic microbes in Arabidopsis thaliana roots. Extensive 16S gene profiling of the microbial communities in the roots of multiple inbred A. thaliana strains has identified 164 OTUs as being significantly enriched in all the root endophyte samples compared to their presence in bulk soil.
Tanentzap, Andrew J; Vicari, Mark; Bazely, Dawn R
Fungal endophytes modify plant-herbivore interactions by producing toxic alkaloids that deter herbivory. However, studies have neglected the direct effects herbivores may have on endophytes. Antifungal properties and signalling effectors in herbivore saliva suggest that evolutionary pressures may select for animals that mitigate the effects of endophyte-produced alkaloids. Here, we tested whether saliva of moose (Alces alces) and European reindeer (Rangifer tarandus) reduced hyphal elongation and production of ergot alkaloids by the foliar endophyte Epichloë festucae associated with the globally distributed red fescue Festuca rubra. Both moose and reindeer saliva reduced the growth of isolated endophyte hyphae when compared with a treatment of distilled water. Induction of the highly toxic alkaloid ergovaline was also inhibited in plants from the core of F. rubra's distribution when treated with moose saliva following simulated grazing. In genotypes from the southern limit of the species' distribution, ergovaline was constitutively expressed, as predicted where growth is environmentally limited. Our results now present the first evidence, to our knowledge, that ungulate saliva can combat plant defences produced by a grass-endophyte mutualism.
Shu Yi eShen
Full Text Available Bacterial endophytes, non-pathogenic bacteria residing within plants, contribute to the growth and development of plants and their ability to adapt to adverse conditions. In order to fully exploit the capabilities of these bacteria, it is necessary to understand the extent to which endophytic communities vary between species and over time. The endophytes of Acer negundo, Ulmus pumila and Ulmus parvifolia were sampled over three seasons and analyzed using culture dependent and independent methods (culture on two media, terminal restriction fragment length polymorphism, and tagged pyrosequencing of 16S ribosomal amplicons. The majority of culturable endophytes isolated were Actinobacteria, and all the samples harbored Bacillus, Curtobacterium, Frigoribacterium, Methylobacterium, Paenibacilllus and Sphingomonas species. Regardless of culture medium used, only the culturable communities obtained in the winter for A. negundo could be distinguished from those of Ulmus spp.. In contrast, the nonculturable communities were dominated by Proteobacteria and Actinobacteria, particularly Erwinia, Ralstonia and Sanguibacter spp.. The presence and abundance of various bacterial classes and phyla changed with the changing seasons. Multivariate analysis on the culture independent data revealed significant community differences between the endophytic communities of A. negundo and Ulmus spp., but overall season was the main determinant of endophytic community structure. This study suggests investigations of the studies ofendophytic populations of urban trees should expect to find significant seasonal and species-specific community differences and sampling should proceed accordingly.
Luís Fernando Albarello Gellen
Full Text Available Linhagens de Trichoderma estão bem difundidas nos processos de controle de fitopatógenos, além disto, para promoção do desenvolvimento e crescimento das culturas onde são inoculados, estes benefícios dão-se pela gama de processos desempenhados por este organismo, os processos são classificados em parasitismo, antibiose e competição, além de secretarem produtos enzimáticos com ações degradantes, compostos voláteis e antimicrobianos. Por meio de testes de produção enzimática, confronto em placa, metabólitos voláteis e sensibilização do agente, os isolados de Trichoderma harzianum mostraram-se como um potente produtor de substâncias antimicrobianas e antifúngicas perante Sthaphylococcus aureus, Streptococcus pyogenes, E. coli, Pseudomonas aeruginosa, E. faecalis e Rhodotorula sp., Candida albicans, Candida parapsilosis e Candida lusitaniae. Palavras-chave: antimicrobianos, antifúngicas, metabólitos, sensibilização. DOI: http://dx.doi.org/10.18561/2179-5746/biotaamazonia.v4n4p91-96
Full Text Available (Kualitas limbah produk pertanian yang difermentasi dengan trichoderma harzianum ABSTRAK. Telah dilakukan penelitian untuk mengetahui pengaruh fermentasi menggunakan Trichoderma harzianum terhadap kualitas limbah pertanian sehingga dapat digunakan sebagai bahan pakan non konvensional pada ternak unggas. Sekam padi, kulit pisang dan kulit nanas digunakan dalam penelitian ini dan difermentasi dengan T. harzianum selama 7 hari. Penelitian dirancang menggunakan Rancangan Acak Lengkap pola faktorial dengan 2 faktor yaitu 3 jenis limbah pertanian (sekam padi, kulit pisang dan kulit nanas dan 4 level T. harzianum ( 0, 4, 8 dan 12%. Setiap unit perlakuan diulang 4 kali. Parameter yang diamati yaitu kandungan bahan kering, protein kasar dan serat kasar. Data yang dihimpun dianalisis menggunakan analisis ragam (ANOVA dan Uji Jarak Berganda Duncan. Hasil penelitian memperlihatkan bahwa terdapat perbedaan yang nyata (P<0.05 kualitas kulit nanas, kulit pisang dan sekam padi setelah difermentasi menggunakan T. harzianum. Kandungan protein kasar kulit nanas dan sekam padi lebih tinggi dibandingkan kulit pisang sedangkan kandungan serat kasarnya lebih rendah. Semakin meningkat level penggunaan T. harzianum pada fermentasi kulit nanas dan sekam padi maka semakin meningkat kandungan protein kasar dan semakin menurun kandungan serat kasarnya. Berbeda dengan kulit pisang, yang kualitasnya tidak nyata dipengaruhi oleh meningkatnya level T. harzianum. Disimpulkan bahwa T. harzianum dapat digunakan untuk memfermentasi limbah pertanian yang kaya kandungan serat untuk meningkatkan kandungan protein dan menurunkan serat kasarnya. Kulit nanas dan sekam padi memiliki kualitas lebih tinggi setelah difermentasi menggunakan 12 % T. harzianum. Kulit pisang tidak disarankan untuk difermentasi menggunakan T. harzianum.
Wees, A.C.M. van; Ent, S. van der; Pieterse, C.M.J.
Beneficial soil-borne microorganisms, such as plant growth promoting rhizobacteria and mycorrhizal fungi,can improve plant performance by inducing systemic defense responses that confer broad-spectrum resistance to plant pathogens and even insect herbivores. Different beneficial microbe-associated m
Ambrose, Karen V.; Zipeng Tian; Yifei Wang; Jordan Smith; Gerben Zylstra; Bingru Huang; Belanger, Faith C.
Epichloë spp. are symbiotic fungal endophytes of many cool season grasses. The presence of the fungal endophytes often confers insect, drought, and disease tolerance to the host grasses. The presence of the fungal endophytes within the host plants does not elicit host defense responses. The molecular basis for this phenomenon is not known. Epichloë festucae, the endophyte of Festuca rubra, expresses a salicylate hydroxylase similar to NahG from the bacterium Pseudomonas putida. Few fungal sal...
Nagabhyru, Padmaja; Dinkins, Randy D; Wood, Constance L; Bacon, Charles W.; Schardl, Christopher L.
Background The endophytic fungus, Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fun...
通过Trichoderma属3个菌株与樟子松枯梢病菌(Sphaeropsis sapinea)对峙培养试验的结果表明:Trichoderma viride 1, Trichoderma viride 2及Trichoderma harzianum对樟子松枯梢病病原菌都有抑制效果,其中Trichoderma viride 2对病原菌的相对抑制效果最好,且其相对抑制效果随着时间的增加而增长,在40h达到最高,为73.55.Trichoderma viride 1和Trichoderma harzianum对病原菌的相对抑制效果在16h达到最高,分别为4.86及2.59.
Sarah J Higginbotham
Full Text Available Fungal endophytes--fungi that grow within plant tissues without causing immediate signs of disease--are abundant and diverse producers of bioactive secondary metabolites. Endophytes associated with leaves of tropical plants are an especially exciting and relatively untapped source of novel compounds. However, one major challenge in drug discovery lies in developing strategies to efficiently recover highly bioactive strains. As part of a 15-year drug discovery project, foliar endophytes were isolated from 3198 plant samples (51 orders, 105 families and at least 232 genera of angiosperms and ferns collected in nine geographically distinct regions of Panama. Extracts from culture supernatants of >2700 isolates were tested for bioactivity (in vitro percent inhibition of growth, % IG against a human breast cancer cell line (MCF-7 and the causative agents of malaria, leishmaniasis, and Chagas' disease. Overall, 32.7% of endophyte isolates were highly active in at least one bioassay, including representatives of diverse fungal lineages, host lineages, and collection sites. Up to 17% of isolates tested per assay were highly active. Most bioactive strains were active in only one assay. Fungal lineages differed in the incidence and degree of bioactivity, as did fungi from particular plant taxa, and greater bioactivity was observed in endophytes isolated from plants in cloud forests vs. lowland forests. Our results suggest that using host taxonomy and forest type to tailor plant collections, and selecting endophytes from specific orders or families for cultivation, will markedly increase the efficiency and efficacy of discovering bioactive metabolites for particular pharmaceutical targets.
Higginbotham, Sarah J; Arnold, A Elizabeth; Ibañez, Alicia; Spadafora, Carmenza; Coley, Phyllis D; Kursar, Thomas A
Fungal endophytes--fungi that grow within plant tissues without causing immediate signs of disease--are abundant and diverse producers of bioactive secondary metabolites. Endophytes associated with leaves of tropical plants are an especially exciting and relatively untapped source of novel compounds. However, one major challenge in drug discovery lies in developing strategies to efficiently recover highly bioactive strains. As part of a 15-year drug discovery project, foliar endophytes were isolated from 3198 plant samples (51 orders, 105 families and at least 232 genera of angiosperms and ferns) collected in nine geographically distinct regions of Panama. Extracts from culture supernatants of >2700 isolates were tested for bioactivity (in vitro percent inhibition of growth, % IG) against a human breast cancer cell line (MCF-7) and the causative agents of malaria, leishmaniasis, and Chagas' disease. Overall, 32.7% of endophyte isolates were highly active in at least one bioassay, including representatives of diverse fungal lineages, host lineages, and collection sites. Up to 17% of isolates tested per assay were highly active. Most bioactive strains were active in only one assay. Fungal lineages differed in the incidence and degree of bioactivity, as did fungi from particular plant taxa, and greater bioactivity was observed in endophytes isolated from plants in cloud forests vs. lowland forests. Our results suggest that using host taxonomy and forest type to tailor plant collections, and selecting endophytes from specific orders or families for cultivation, will markedly increase the efficiency and efficacy of discovering bioactive metabolites for particular pharmaceutical targets.
Previous work has shown that leaf-cutting ants prefer to cut leaf material that is relatively low in fungal endophyte content. Such a preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in thei...
Shymanovich, Tatsiana; Saari, Susanna; Lovin, Mary E; Jarmusch, Alan K; Jarmusch, Scott A; Musso, Ashleigh M; Charlton, Nikki D; Young, Carolyn A; Cech, Nadja B; Faeth, Stanley H
Epichloid endophytes are well known symbionts of many cool-season grasses that may alleviate environmental stresses for their hosts. For example, endophytes produce alkaloid compounds that may be toxic to invertebrate or vertebrate herbivores. Achnatherum robustum, commonly called sleepygrass, was aptly named due to the presence of an endophyte that causes toxic effects to livestock and wildlife. Variation in alkaloid production observed in two A. robustum populations located near Weed and Cloudcroft in the Lincoln National Forest, New Mexico, suggests two different endophyte species are present in these populations. Genetic analyses of endophyte-infected samples revealed major differences in the endophyte alkaloid genetic profiles from the two populations, which were supported with chemical analyses. The endophyte present in the Weed population was shown to produce chanoclavine I, paspaline, and terpendoles, so thus resembles the previously described Epichloë funkii. The endophyte present in the Cloudcroft population produces chanoclavineI, ergonovine, lysergic acid amide, and paspaline, and is an undescribed endophyte species. We observed very low survival rates for aphids feeding on plants infected with the Cloudcroft endophyte, while aphid survival was better on endophyte infected plants in the Weed population. This observation led to the hypothesis that the alkaloid ergonovine is responsible for aphid mortality. Direct testing of aphid survival on oat leaves supplemented with ergonovine provided supporting evidence for this hypothesis. The results of this study suggest that alkaloids produced by the Cloudcroft endophyte, specifically ergonovine, have insecticidal properties.
Fungal endophytes have been shown to improve abiotic and biotic stress response in plants. Grasses growing along the Oregon coast are exposed to harsh conditions and may harbor endophytes that enable them to survive and grow under these conditions. Endophytic fungi were isolated from thirty-four gra...
Hardoim, Pablo R.; van Overbeek, Leo S.; van Elsas, Jan Dirk
Bacterial endophytes live inside plants for at least part of their life cycle. Studies of the interaction of endophytes with their host plants and their function within their hosts are important to address the ecological relevance of endophytes. The modulation of ethylene levels in plants by bacteri
Ergot alkaloids in endophyte-infected grasses inhibit prolactin (PRL) secretion and may reduce milk production of cows consuming endophyte-infected grasses. We hypothesized that consumption of endophyte-infected fescue during the dry period inhibits mammary differentiation and subsequent milk produ...
To understand more about the enhanced drought tolerance conferred by the endophyte Neotyphodium coenophialum in tall fescue, we analyzed the effect of the endophyte on genetically identical tall fescue clones with (E+) and without the endophyte (E-), by generating E- plants through fungicide trea...
A column was written to discuss planting novel endophyte tall fescue for alleviating fescue toxicosis. Endophyte-free tall fescue cultivars can be grazed as a non-toxic alternative, but it maust be understood that it is the endophyte, through production of alkaloids other than ergot alkaloids, that...
Venugopalan, Aarthi; Srivastava, Smita
Many reports have been published on bioprospecting of endophytic fungi capable of producing high value bioactive molecules like, paclitaxel, vincristine, vinblastine, camptothecin and podophyllotoxin. However, commercial exploitation of endophytes for high value-low volume plant secondary metabolites remains elusive due to widely reported genomic instability of endophytes in the axenic culture. While most of the endophyte research focuses on screening endophytes for novel or existing high value biomolecules, very few reports seek to explore the possible mechanisms of production of host-plant associated or novel secondary metabolites in these organisms. With an overview of host-endophyte relationship and its possible impact on the secondary metabolite production potential of endophytes, the review highlights the evidence reported for and against the presence of host-independent biosynthetic machinery in endophytes. The review aims to address the question, why should and how can endophytes be exploited for large scale in vitro production of high value phytochemicals? In this regard, various bioprocess optimization strategies that have been applied to sustain and enhance the product yield from the endophytes have also been described in detail. Further, techniques like mixed fermentation/co-cultivation and use of epigenetic modifiers have also been discussed as potential strategies to activate cryptic gene clusters in endophytes, thereby aiding in novel metabolite discovery and overcoming the limitations associated with axenic culture of endophytes.
Qualhato, Thiago Fernandes; Lopes, Fabyano Alvares Cardoso; Steindorff, Andrei Stecca; Brandão, Renata Silva; Jesuino, Rosália Santos Amorim; Ulhoa, Cirano José
Trichoderma spp. are used for biocontrol of several plant pathogens. However, their efficient interaction with the host needs to be accompanied by production of secondary metabolites and cell wall-degrading enzymes. Three parameters were evaluated after interaction between four Trichoderma species and plant-pathogenic fungi: Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum. Trichoderma harzianum and T. asperellum were the most effective antagonists against the pathogens. Most of the Trichoderma species produced toxic volatile metabolites, having significant effects on growth and development of the plant pathogens. When these species were grown in liquid cultures with cell walls from these plant pathogens, they produced and secreted β-1,3-glucanase, NAGAse, chitinase, acid phosphatase, acid proteases and alginate lyase.
ZHANG Yue-li; LIU Kai-qi; XIANG Mei-mei; LIU Ren
@@ One hundred and fifty one isolates of Trichoderma were collected mainly from more than 40 soil samples and other materials in Guangdong Province (including Chigang, Zhanjiang, Wuchuan,Panyu, Zhaoqing, Dongguan, Humen, Qingyuan, Guanzhou) and the soil samples were also from different plant rhizosphere (including rice, different fruits and different vegetables). It was shown that 39 isolates of Trichoderma grew faster than other isolates using growth velocity experiments.The 39 isolates could effectively inhibit Fusarium oxysporum f. sp. cubense (E. F. Sm) Sny. &Hans.by dual cultural experiments. The inhibited activity included the antifungal activities of its metabolite,mycoparasitic activities and the lytic enzymes by dual culture, electronic microcopy and enzyme assay.At present, studies on the taxonomy of the 151 isolates of Trichoderma are carried out in our experiments, some Trichoderma species aggregates will be identified according to the taxonomy system revised by Rifai and Bissett.
@@ Over forty Trichoderma harzianum isolates have been screened in solid substrate fermentation (SSF)for chitinase production. Strains were isolated from Asian soil and tree bark samples. Identification was performed in Canada and Austria by classical and molecular taxonomical methods.
Elham Siassi; YANG Qian
There is a method for investigating the transformation of resistance gene of carbendazim into Trichoderma harzianum. In order to introduce the resistance to benzimidazole fungicide into bio-control microorganism Trichoderma harzianum was transformed with the resistance gene. In this study, we investigate resistance level and calculate EC 50 ( effective concentration of carbendazim that can survive 50% of Trichoderma harzianum in that concentration) and stability of the resistance for the transformant isolate of Trichoderma harzianum.Results show the transformants can growth on the medium containing more than 1 000 μg/ml carbendazim and the resistance is stabled after 10 times transfer on non-selective medium and have EC 50 average about, 1 200μg/ml.
Wang, Mingyu; Yang, Hui; Zhang, Meiling; Liu, Kuimei; Wang, Hanbin; Luo, Yi; Fang, Xu
Trichoderma reesei is the most important industrial cellulase-producing filamentous fungus. Although its molecular physiology has been investigated, the signal transduction pathways are not fully understood. In particular, the role of casein kinase II (CKII) is not yet clear. In this work, we carried out functional investigations on a catalytic subunit of CKII, CKIIα2. Comparison of the phenotypic features of T. reesei parent and Δck2α2 strains showed significant changes following ck2α2 disruption. T. reesei Δck2α2 form significantly smaller mycelial pellets in glucose-containing liquid minimum media, have shorter and fewer branch hyphae, produce smaller amounts of chitinases, produce more spores, show more robust growth on glucose-containing agar plates, and consume glucose at a significantly higher rate. Suggestions can be made that CKIIα2 governs chitinase expression, and the disruption of ck2α2 results in lower levels of chitinase production, leading to a weaker cell wall disruption capability, further resulting in weaker hyphal branching, which eventually leads to smaller mycelial pellets in liquid media. Further conclusions can be made that CKIIα2 is involved in repression of sporulation and glucose metabolism, which is consistent with the proposal that CKIIα2 represses global metabolism. These observations make the deletion of ck2α2 a potentially beneficial genetic disruption for T. reesei during industrial applications, as smaller mycelial pellets, more spores and more robust glucose metabolism are all desired traits for industrial fermentation. This work reports novel unique functions of a CKII catalytic subunit and is also the first genetic and physiological investigation on CKII in T. reesei.
Colavolpe, María Belén; Mejía, Santiago Jaramillo; Albertó, Edgardo
Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 °C), immersion in hot water (60 and 80 °C), and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (10(5) conidia/mL) and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 °C for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species.
María Belén Colavolpe
Full Text Available Trichoderma spp is the cause of the green mold disease in mushroom cultivation production. Many disinfection treatments are commonly applied to lignocellulose substrates to prevent contamination. Mushroom growers are usually worried about the contaminations that may occur after these treatments during handling or spawning. The aim of this paper is to estimate the growth of the green mold Trichoderma sp on lignocellulose substrates after different disinfection treatments to know which of them is more effective to avoid contamination during spawning phase. Three different treatments were assayed: sterilization (121 ºC, immersion in hot water (60 and 80 ºC, and immersion in alkalinized water. Wheat straw, wheat seeds and Eucalyptus or Populus sawdust were used separately as substrates. After the disinfection treatments, bagged substrates were sprayed with 3 mL of suspension of conidia of Trichoderma sp (10(5 conidia/mL and then separately spawned with Pleurotus ostreatus or Gymnopilus pampeanus. The growth of Trichoderma sp was evaluated based on a qualitative scale. Trichoderma sp could not grow on non-sterilized substrates. Immersions in hot water treatments and immersion in alkalinized water were also unfavorable treatments for its growth. Co- cultivation with mushrooms favored Trichoderma sp growth. Mushroom cultivation disinfection treatments of lignocellulose substrates influence on the growth of Trichoderma sp when contaminations occur during spawning phase. The immersion in hot water at 60 ºC for 30 min or in alkalinized water for 36 h, are treatments which better reduced the contaminations with Trichoderma sp during spawning phase for the cultivation of lignicolous species.
Szakacs G; Tavaszi A
@@ Though there are successful commercial biocontrol products with Trichoderma spp. In many countries including US, Israel and Europe, their usefulness is limited in cold environments such as mid-and northern part of Europe, US and Canada, especially in the late fall, winter and early spring period.Trichoderma isolates capable of growing at low temperatures (5-10 ℃) and showing good antagonistic properties against plant pathogenic fungi may have therefore both scientific and commercial value.
Larissa Brandão Góes; Ana Bolena Lima da Costa; Laurineide Lopes de Carvalho Freire; Neiva Tinti de Oliveira
Random Amplified Polymorphic DNA (RAPD) procedure was used to examine the genetic variability among fourteen isolates of Trichoderma and their ability to antagonize Rhizoctonia solani using a dual-culture assay for correlation among RAPD products and their hardness to R. solani. Seven oligodeoxynucleotide primers were selected for the RAPD assays which resulted in 197 bands for 14 isolates of Trichoderma. The data were entered into a binary matrix and a similarity matrix was constructed using...
We describe the second known case of human infection by Trichoderma harzianum. A disseminated fungal infection was detected in the postmortem examination of a renal transplant recipient and confirmed in culture. The only other reported infection by this fungus caused peritonitis in a diabetic patient. The in vitro antifungal susceptibilities of the clinical strain and three other strains of Trichoderma species to six antifungal drugs are provided. This case illustrates the widening spectrum o...
Full Text Available Abstract Metabolites of mycoparasitic fungal species such as Trichoderma harzianum 88 have important biological roles. In this study, two new ketoacyl synthase (KS fragments were isolated from cultured Trichoderma harzianum 88 mycelia using degenerate primers and analysed using a phylogenetic tree. The gene fragments were determined to be present as single copies in Trichoderma harzianum 88 through southern blot analysis using digoxigenin-labelled KS gene fragments as probes. The complete sequence analysis in formation of pksT-1 (5669 bp and pksT-2 (7901 bp suggests that pksT-1 exhibited features of a non-reducing type I fungal PKS, whereas pksT-2 exhibited features of a highly reducing type I fungal PKS. Reverse transcription polymerase chain reaction indicated that the isolated genes are differentially regulated in Trichoderma harzianum 88 during challenge with three fungal plant pathogens, which suggests that they participate in the response of Trichoderma harzianum 88 to fungal plant pathogens. Furthermore, disruption of the pksT-2 encoding ketosynthase–acyltransferase domains through Agrobacterium -mediated gene transformation indicated that pksT-2 is a key factor for conidial pigmentation in Trichoderma harzianum 88.
Cocaign, Angélique; Bui, Linh-Chi; Silar, Philippe; Chan Ho Tong, Laetitia; Busi, Florent; Lamouri, Aazdine; Mougin, Christian; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Dairou, Julien
Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.
Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad
Abstract This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract. PMID:26691463
Khalili, Elham; Sadravi, Mehdi; Naeimi, Shahram; Khosravi, Vahid
Brown spot caused by Bipolaris oryzae is an important rice disease in Southern coast of Caspian Sea, the major rice growing region in Iran. A total of 45 Trichoderma isolates were obtained from rice paddy fields in Golestan and Mazandaran provinces which belonged to Trichoderma harzianum, T. virens and T. atroviride species. Initially, they were screened against B. oryzae by antagonism tests including dual culture, volatile and nonvolatile metabolites and hyperparasitism. Results showed that Trichoderma isolates can significantly inhibit mycelium growth of pathogen in vitro by producing volatile and nonvolatile metabolites Light microscopic observations showed no evidence of mycoparasitic behaviour of the tested isolates of Trichoderma spp. such as coiling around the B. oryzae. According to in vitro experiments, Trichoderma isolates were selected in order to evaluate their efficacy in controlling brown spot in glasshouse using seed treatment and foliar spray methods. Concerning the glasshouse tests, two strains of T. harzianum significantly controlled the disease and one strain of T. atroviride increased the seedling growth. It is the first time that the biological control of rice brown spot and increase of seedling growth with Trichoderma species have been studied in Iran.
Florencio, C; Cunha, F M; Badino, A C; Farinas, C S
The development of new cost-effective bioprocesses for the production of cellulolytic enzymes is needed in order to ensure that the conversion of biomass becomes economically viable. The aim of this study was to determine whether a novel sequential solid-state and submerged fermentation method (SF) could be validated for different strains of the Trichoderma genus. Cultivation of the Trichoderma reesei Rut-C30 reference strain under SF using sugarcane bagasse as substrate was shown to be favorable for endoglucanase (EGase) production, resulting in up to 4.2-fold improvement compared with conventional submerged fermentation. Characterization of the enzymes in terms of the optimum pH and temperature for EGase activity and comparison of the hydrolysis profiles obtained using a synthetic substrate did not reveal any qualitative differences among the different cultivation conditions investigated. However, the thermostability of the EGase was influenced by the type of carbon source and cultivation system. All three strains of Trichoderma tested (T. reesei Rut-C30, Trichoderma harzianum, and Trichoderma sp INPA 666) achieved higher enzymatic productivity when cultivated under SF, hence validating the proposed SF method for use with different Trichoderma strains. The results suggest that this bioprocess configuration is a very promising development for the cellulosic biofuels industry.
Prabhakaran, Narayanasamy; Prameeladevi, Thokala; Sathiyabama, Muthukrishnan; Kamil, Deeba
Different isolates of Trichoderma were isolated from soil samples which were collected from different part of India. These isolates were grouped into four Trichoderma species viz., Trichoderma asperellum (Ta), T. harzianum (Th), T. pseudokoningii (Tp) and T. longibrachiatum (Tl) based on their morphological characters. Identification of the above isolates was also confirmed through ITS region analysis. These Trichoderma isolates were tested for in vitro biological control of Alternaria solani, Bipolaris oryzae, Pyricularia oryzae and Sclerotinia scierotiorum which cause serious diseases like early blight (target spot) of tomato and potato, brown leaf spot disease in rice, rice blast disease, and white mold disease in different plants. Under in vitro conditions, all the four species of Trichoderma (10 isolates) proved 100% potential inhibition against rice blast pathogen Pyracularia oryzae. T. harzianum (Th-01) and T. asperellum (Ta-10) were effective with 86.6% and 97.7%, growth inhibition of B. oryzae, respectively. Among others, T. pseudokoningii (Tp-08) and T. Iongibrachiatum (Tl-09) species were particularly efficient in inhibiting growth of S. sclerotiorum by 97.8% and 93.3%. T. Iongibrachiatum (TI-06 and TI-07) inhibited maximum mycelial growth of A. solani by 87.6% and 84.75. However, all the T. harzianum isolates showed significantly higher inhibition against S. sclerotiorum (CD value 9.430), causing white mold disease. This study led to the selection of potential Trichoderma isolates against rice blast, early blight, brown leaf spot in rice and white mold disease in different crops.
Asad, Saeed Ahmad; Tabassum, Ayesha; Hameed, Abdul; Hassan, Fayyaz Ul; Afzal, Aftab; Khan, Sabaz Ali; Ahmed, Rafiq; Shahzad, Muhammad
This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.
Full Text Available Paddy var Rojoleleis asuperior paddy come from Klaten that released by Department of Agriculture in 2003. Its superior properties are resistant to pests leaf hoppers, fluffier, and fragrant. To increase the productivity of paddy that are of ten used by farmers is to use chemical-based fertilizers. The use of these chemicals will effect to adisruption of ecosystem balancing, reduction the amount of soil microflora which essential forplants. Endophytic bacteria are symbiotic microorganisms living within plant tissues, and does not cause negative effects on the host plant. Endophytic bacteria have a capability increasing crop productivity by producing growth hormone, contributes to plant health, and as bio-control agents. Some endophytic bacteria which contribute to plant growth are: Pseudomonas sp., Enterobacter sp., Staphylococcus sp., Azotobacter sp., And Azospirilum sp., Whereas endophytic bacteria that contribute to the health and plant protection several of them are: Pseudomonas sp., Serratia sp. ,Clavibacter sp., and Bacillus sp. This study was conducted to investigate potential of endophytic bacteria to increase Paddy var Rojolele productivity based on its ability to produce extracellular enzymes and resistance to multiple types of antibiotics. The method were endophytic bacteria isolation from three Paddy varRojolele plants, extracellular enzymes detection and antibiotic resistance testing to chloramfinekol, ampicillin and kanamycin. As the result, 43isolateswere isolated from Paddy var Rojolele. Four isolatesamong them havethe ability to produce extra cellular enzym esandresistant toampicillin, kanamycin, and chloramfinekol. Extra cellular enzyme production capability and resistance to antibiotics makes endophytic bacteria are potentialto improveplant health and also asbio-control agentwhich then willaffect to the productivity of rice. To further ensure its potential to plant, more research is needed.
Raman, A; Wheatley, W; Popay, A
Insect association with fungi has a long history. Theories dealing with the evolution of insect herbivory indicate that insects used microbes including fungi as their principal food materials before flowering plants evolved. Subtlety and the level of intricacy in the interactions between insects and fungi indicate symbiosis as the predominant ecological pattern. The nature of the symbiotic interaction that occurs between two organisms (the insect and the fungus), may be either mutualistic or parasitic, or between these two extremes. However, the triangular relationship involving three organisms, viz., an insect, a fungus, and a vascular plant is a relationship that is more complicated than what can be described as either mutualism or parasitism, and may represent facets of both. Recent research has revealed such a complex relationship in the vertically transmitted type-I endophytes living within agriculturally important grasses and the pestiferous insects that attack them. The intricacy of the association depends on the endophytic fungus-grass association and the insect present. Secondary compounds produced in the endophytic fungus-grass association can provide grasses with resistance to herbivores resulting in mutualistic relationship between the fungus and the plant that has negative consequences for herbivorous insects. The horizontally transmitted nongrass type-II endophytes are far less well studied and as such their ecological roles are not fully understood. This forum article explores the intricacy of dependence in such complex triangular relationships drawing from well-established examples from the fungi that live as endophytes in vascular plants and how they impact on the biology and evolution of free-living as well as concealed (e.g., gall-inducing, gall-inhabiting) insects. Recent developments with the inoculation of strains of type-I fungal endophytes into grasses and their commercialization are discussed, along with the possible roles the endophytic
Purbowatiningrum R Sarjono
Full Text Available Telah kita ketahui bahwa eceng gondok merupakan salah satu sumber selulosa yang melimpah di alam dan dapat dimanfaatkan sebagai sumber karbon bagi jamur Trichoderma viride. Eceng gondok memiliki bobot kering selulosa 21,5%, hemiselulosa 33,9% dan lignin 7,01%. Trichoderma viride adalah jamur saprofit yang berpotensi memproduksi selulase yang mampu mendegradasi ikatan β-1,4-glikosida pada rantai selulosa untuk menghasilkan glukosa. Glukosa dapat dimanfaatkan dalam produksi sirup gula, asam organik dan bioetanol. Penelitian ini bertujuan untuk mendapatkan Trichoderma viride yang mampu tumbuh pada media pertumbuhan hasil modifikasi eceng gondok serta memperoleh temperatur optimum aktivitas Trichoderma viride dalam menghidrolisis eceng gondok dan waktu fermentasi terbaik dalam menghasilkan glukosa. Proses pertama adalah persiapan sampel enceng gondok meliputi delignifikasi, kurva pertumbuhan Trichoderma viride dibuat dalam media modifikasi eceng gondok untuk mengetahui waktu optimum pertumbuhan Trichoderma viride. Penentuan temperatur optimum dan waktu fermentasi terbaik dari aktivitas Trichoderma viride didasarkan pada glukosa yang dihasilkan dari hidrolisis selulosa pada eceng gondok menggunakan metode Nelson Somogyi. Berdasarkan penelitian diperoleh hasil bahwa Trichoderma viride mampu tumbuh pada media modifikasi eceng gondok. Temperatur optimum aktivitas Trichoderma viride dalam menghidrolisis selulosa pada eceng gondok adalah 35oC dan waktu fermentasi terbaik dihasilkannya glukosa pada jam ke-96 yaitu sebesar 1,3864 mg/L.
Santhosh Wilson Goveas
Full Text Available Enumeration of the endophytic fungi from the red listed, critically endangered medicinal plant, Coscinium fenestratum was investigated for the first time. The ubiquitous presence of 41 endophytic fungi belonging to sixteen different taxa was identified from 195 samples of healthy leaves and stem using traditional morphological methods. The overall colonization rate of endophytes in both the leaf and the stem was found to be 21.02%.The stem showed low percentage frequency of colonization of the endophytic fungi when compared to leaf segments. Among the endophytic flora, Phomopsis jacquiniana was found to be the core-group fungus with a colonization frequency of 4.6%.
Erica Aparecida de Souza Pedro
Full Text Available O objetivo deste trabalho foi avaliar a capacidade de Trichoderma spp. em promover o crescimento de plantas de feijão e reduzir a severidade da antracnose do feijoeiro (Colletotrichum lindemuthianum, bem como identificar os isolados mais eficientes. Sessenta isolados de Trichoderma spp. foram avaliados quanto à capacidade de promoção do crescimento nas plantas. Os sete isolados que mais se destacaram foram adicionados ao substrato de cultivo e avaliados quanto à redução na severidade da antracnose em plantas de feijão tratadas com conídios de C. lindemuthianum. Os mais eficientes no controle da doença foram identificados por sequenciamento de DNA. O isolado IB 28/07 foi avaliado nas concentrações 0,5, 1, 1,5 e 2% (peso:volume, que reduziram a severidade da doença em 41,51, 55,15, 81,82 e 96,06%, respectivamente. Os isolados mais eficientes de Trichoderma spp. podem proporcionar aumentos superiores a 30% na produção de matéria seca da parte aérea das plantas e reduzir a severidade da doença entre 63 e 98%. Esses isolados foram identificados como pertencentes às espécies Trichoderma harzianum, T. strigosum e T. theobromicola.The objective of this work was to evaluate the ability of Trichoderma spp. to promote growth of common bean plants and to reduce severity of anthracnose (Colletotrichum lindemuthianum, as well as to identify the best performing isolates. Sixty Trichoderma spp. isolates were evaluated as to their capacity to promote growth in common bean. The seven isolates that stood out were added to the culture substrate and assessed for reduction in severity of anthracnose in bean plants treated with C. lindemuthianum conidia. The most efficient isolates in controlling the disease were identified by DNA sequencing. The IB 28/07 isolate was evaluated in the concentrations 0.5, 1, 1.5, and 2% (weight:volume, which reduced disease severity in 41.51, 55.15, 81.82, and 96.06%, respectively. The most efficient Trichoderma spp
Gupta, Vijai Kumar; Steindorff, Andrei Stecca; de Paula, Renato Graciano; Silva-Rocha, Rafael; Mach-Aigner, Astrid R; Mach, Robert L; Silva, Roberto N
The ascomycete Trichoderma reesei is one of the most well studied cellulolytic microorganisms. This fungus is widely used in the biotechnology industry, mainly in the production of biofuels. Due to its importance, its genome was sequenced in 2008, opening new avenues to study this microorganism. In this 'post-genomic' era, a transcriptomic and proteomic era has emerged. Here, we present an overview of new findings in the gene expression regulation network of T. reesei. We also discuss new rational strategies to obtain mutants that produce hydrolytic enzymes with a higher yield, using metabolic engineering. Finally, we present how synthetic biology strategies can be used to create engineered promoters to efficiently synthesize enzymes for biomass degradation to produce bioethanol.
Mayerhofer, Michael S; Kernaghan, Gavin; Harper, Karen A
Fungal root endophytes are plant associates that colonize root tissue internally without causing any obvious harm to their host. Although ubiquitous, this relationship is not well understood. Our objectives were to determine the effects of fungal root endophyte inoculation on plant biomass and nitrogen concentration by conducting an extensive meta-analysis. We also explored the effects of experimental conditions on the host-endophyte relationship. We performed analyses weighted with non-parametric variance on plant response to root endophytes from the Ascomycetes (excluding the Clavacipitaceae), including categorical analyses of 21 experimental factors, ranging from the identity of the host and the endophyte, to the composition of the growing medium. The response of total biomass to endophyte inoculation was 18% lower than non-inoculated controls, while individually, root biomass, shoot biomass, and nitrogen concentration responses to endophyte inoculation were neutral. The identities of both the host and the endophyte had an influence, as did the original source of the endophyte (whether or not the isolate used originated from the same host species). Experimental conditions also influenced the plant-endophyte relationship, with the most important being the availability and sources of carbon and organic nitrogen, particularly peat moss. Although our analysis demonstrates that overall plant biomass and nitrogen concentration responses to ascomycetous root endophyte inoculation is neutral to negative, these results are somewhat confounded by among-study differences in experimental conditions, which undoubtedly contribute to the high levels of variability in plant response seen in the literature.
Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth
Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.
Nisa, Humeera; Kamili, Azra N; Nawchoo, Irshad A; Shafi, Sana; Shameem, Nowsheen; Bandh, Suhaib A
Endophytic fungi are those that live internally in apparently healthy and asymptomatic hosts. Endophytic fungi appear to be ubiquitous; indeed, no study has yet shown the existence of a plant species without endophytes. High species diversity is another characteristic of endophytic mycobiota which is depicted by the fact that it is quite common for endophyte surveys to find assemblages consisting of more than 30 fungal species per host plant species. Medicinal plants had been used to isolate and characterize directly the bioactive metabolites. However, the discovery of fungal endophytes inside these plants with capacity to produce the same compounds shifted the focus of new drug sources from plants to fungi. Bioactive natural products from endophytic fungi, isolated from different plant species, are attracting considerable attention from natural product chemists and biologists alike which is clearly depicted by the steady increase of publications devoted to this topic during the recent years. This review will highlight the chemical potential of endophytic fungi with focus on the detection of pharmaceutically valuable plant constituents as products of fungal biosynthesis. In addition, it will cover newly discovered endophytic fungi and also new bioactive metabolites reported in recent years from fungal endophytes. It summarizes the up-to-date and comprehensive information on bioactive compounds from endophytic fungi by having done a thorough survey of literature.
Kusari, Parijat; Kusari, Souvik; Lamshöft, Marc; Sezgin, Selahaddin; Spiteller, Michael; Kayser, Oliver
Bacteria predominantly use quorum sensing to regulate a plethora of physiological activities such as cell-cell crosstalk, mutualism, virulence, competence, biofilm formation, and antibiotic resistance. In this study, we investigated how certain potent endophytic bacteria harbored in Cannabis sativa L. plants use quorum quenching as an antivirulence strategy to disrupt the cell-to-cell quorum sensing signals in the biosensor strain, Chromobacterium violaceum. We used a combination of high-performance liquid chromatography high-resolution mass spectrometry (HPLC-ESI-HRMS(n)) and matrix-assisted laser desorption ionization imaging high-resolution mass spectrometry (MALDI-imaging-HRMS) to first quantify and visualize the spatial distribution of the quorum sensing molecules in the biosensor strain, C. violaceum. We then showed, both quantitatively and visually in high spatial resolution, how selected endophytic bacteria of C. sativa can selectively and differentially quench the quorum sensing molecules of C. violaceum. This study provides fundamental insights into the antivirulence strategies used by endophytes in order to survive in their ecological niches. Such defense mechanisms are evolved in order to thwart the plethora of pathogens invading associated host plants in a manner that prevents the pathogens from developing resistance against the plant/endophyte bioactive secondary metabolites. This work also provides evidence towards utilizing endophytes as tools for biological control of bacterial phytopathogens. In continuation, such insights would even afford new concepts and strategies in the future for combating drug resistant bacteria by quorum-inhibiting clinical therapies.
Andrade-Linares, Diana Rocio; Grosch, Rita; Restrepo, Silvia; Krumbein, Angelika; Franken, Philipp
Non-mycorrhizal fungal root endophytes can be found in all natural and cultivated ecosystems, but little is known about their impact on plant performance. The impact of three mitosporic dark septate endophytes (DSE48, DSE49 and Leptodontidium orchidicola) on tomato plant characteristics was studied. Their effects on root and shoot growth, their influence on fruit yield and fruit quality parameters and their ability to diminish the impact of the pathogen Verticillium dahliae were investigated. While shoot biomass of young plants was enhanced between 10% and 20% by the endophytes DSE48 and L. orchidicola in one of two experiments and by DSE49 in both experiments, vegetative growth parameters of 24-week-old plants were not affected except a reproducible increase of root diameter by the isolate DSE49. Concerning fruit yield and quality, L. orchidicola could double the biomass of tomatoes and increased glucose content by 17%, but this was dependent on date of harvest and on root colonisation density. Additionally, the endophytes DSE49 and L. orchidicola decreased the negative effect of V. dahliae on tomato, but only at a low dosage of the pathogen. This indicates that the three dark septate endophytes can have a significant impact on tomato characters, but that the effects are only obvious at early stages of vegetative and generative development and currently too inconsistent to recommend the application of these DSEs in horticultural practice.
Cabezas, Luisa; Calderon, Carolina; Medina, Luis Miguel; Bahamon, Isabela; Cardenas, Martha; Bernal, Adriana Jimena; Gonzalez, Andrés; Restrepo, Silvia
Endophytes are microorganisms that asymptomatically invade plant tissues. They can stimulate plant growth and/or provide defense against pathogen attacks through the production of secondary metabolites. Most endophyte species are still unknown, and because they may have several applications, the study of their metabolic capabilities is essential. We characterized 100 endophytes isolated from Espeletia spp., a genus unique to the paramo ecosystem, an extreme environment in the Andean mountain range. We evaluated the cellulolytic potential of these endophytes on the saccharification of the oil palm empty fruit bunch (OPEFB). The total cellulolytic activity was measured for each endophyte on filter paper (FPA). In addition, the specific carboxymethyl cellulase (CMCase), exoglucanase, and β-glucosidase activities were determined. We found four fungi positive for cellulases. Of these fungi, Penicillium glabrum had the highest cellulolytic activity after partial purification, with maximal CMCase, exoglucanase and β-glucosidase enzyme activities of 44.5, 48.3, and 0.45 U/ml, respectively. Our data showed that the bioprospection of fungi and the characterization of their enzymes may facilitate the process of biofuel production.
Barelli, Larissa; Moonjely, Soumya; Behie, Scott W; Bidochka, Michael J
This review examines the symbiotic, evolutionary, proteomic and genetic basis for a group of fungi that occupy a specialized niche as insect pathogens as well as endophytes. We focus primarily on species in the genera Metarhizium and Beauveria, traditionally recognized as insect pathogenic fungi but are also found as plant symbionts. Phylogenetic evidence suggests that these fungi are more closely related to grass endophytes and diverged from that lineage ca. 100 MYA. We explore how the dual life cycles of these fungi as insect pathogens and endophytes are coupled. We discuss the evolution of insect pathogenesis while maintaining an endophytic lifestyle and provide examples of genes that may be involved in the transition toward insect pathogenicity. That is, some genes for insect pathogenesis may have been co-opted from genes involved in endophytic colonization. Other genes may be multifunctional and serve in both lifestyle capacities. We suggest that their evolution as insect pathogens allowed them to effectively barter a specialized nitrogen source (i.e. insects) with host plants for photosynthate. These ubiquitous fungi may play an important role as plant growth promoters and have a potential reservoir of secondary metabolites.
van Kan, Jan A L; Shaw, Michael W; Grant-Downton, Robert T
Plant pathology has a long-standing tradition of classifying microbes as pathogens, endophytes or saprophytes. Lifestyles of pathogens are categorized as biotrophic, necrotrophic or hemibiotrophic. Botrytis species are considered by many to be archetypal examples of necrotrophic fungi, with B. cinerea being the most extensively studied species because of its broad host range and economic impact. In this review, we discuss recent work which illustrates that B. cinerea is capable of colonizing plants internally, presumably as an endophyte, without causing any disease or stress symptoms. The extent of the facultative endophytic behaviour of B. cinerea and its relevance in the ecology and disease epidemiology may be vastly underestimated. Moreover, we discuss the recent discovery of a novel Botrytis species, B. deweyae, which normally grows as an endophyte in ornamental daylilies (Hemerocallis), but displays facultative pathogenic behaviour, and is increasingly causing economic damage. We propose that the emergence of endophytes 'gone rogue' as novel diseases may be related to increased inbreeding of hybrid lines and reduced genetic diversity. These observations lead us to argue that the sometimes inflexible classification of pathogenic microbes by their lifestyles requires serious reconsideration. There is much more variety to the interactions of Botrytis with its hosts than the eye (or the plant pathologist) can see, and this may be true for other microbes interacting with plants.
Full Text Available Abstract Background Drug resistance in bacteria has become a global concern and the search for new antibacterial agents is urgent and ongoing. Endophytes provide an abundant reservoir of bioactive metabolites for medicinal exploitation, and an increasing number of novel compounds are being isolated from endophytic fungi. Ophiopogon japonicus, containing compounds with antibacterial activity, is a traditional Chinese medicinal plant used for eliminating phlegm, relieving coughs, latent heat in the lungs, and alleviating diabetes mellitus. We investigated the antimicrobial activities of 30 strains of O. japonicus. Methods Fungal endophytes were isolated from roots and stems of O. japonicus collected from Chongqing City, southwestern China. Mycelial extracts (MC and fermentation broth (FB were tested for antimicrobial activity using peptide deformylase (PDF inhibition fluorescence assays and MTT cell proliferation assays. Results A total of 30 endophytic strains were isolated from O. japonicus; 22 from roots and eight from stems. 53.33% of the mycelial extracts (MC and 33.33% of the fermentation broths (FB displayed potent inhibition of PDF. 80% of MC and 33.33% of FB significantly inhibited Staphylococcus aureus. 70% of MC and 36.67% of FB showed strong activities against Cryptococcus neoformans. None showed influence on Escherichia coli. Conclusion The secondary metabolites of endophytic fungi from O. japonicus are potential antimicrobial agents.
Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).
Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B
Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.
Miller, Kristin I; Qing, Chen; Sze, Daniel Man-Yuen; Roufogalis, Basil D; Neilan, Brett A
The bioactive compounds of medicinal plants are products of the plant itself or of endophytes living inside the plant. Endophytes isolated from eight different anticancer plants collected in Yunnan, China, were characterized by diverse 16S and 18S rRNA gene phylogenies. A functional gene-based molecular screening strategy was used to target nonribosomal peptide synthetase (NRPS) and type I polyketide synthase (PKS) genes in endophytes. Bioinformatic analysis of these biosynthetic pathways facilitated inference of the potential bioactivity of endophyte natural products, suggesting that the isolated endophytes are capable of producing a plethora of secondary metabolites. All of the endophyte culture broth extracts demonstrated antiproliferative effects in at least one test assay, either cytotoxic, antibacterial or antifungal. From the perspective of natural product discovery, this study confirms the potential for endophytes from medicinal plants to produce anticancer, antibacterial and antifungal compounds. In addition, PKS and NRPS gene screening is a valuable method for screening isolates of biosynthetic potential.
Helander, M.L.; Neuvonen, S. (Turku Univ., Turku (F)); Sieber, T.N.; Petrini, O. (Swiss Federal Inst. of Technology, Zurich (Switzerland))
Within- and among-tree variation in assemblages of endophytic fungi in Scots pine (Pinus sylvestris) needles were studied in a subarctic area where background pollution values are low; the effects of tree density and prolonged simulated acid rain on the occurrence of endophytic fungi were investigated. The needle endophyte most frequently isolated was Cenangium ferruginosum, accounting for 64% of all fungal individuals, followed by Cyclaneusma minus (12% of all individuals). Old needles were colonized more frequently by endophytes than young ones. In young needles the colonization by endophytes increased during the summer, whereas in old ones no seasonal variation was detected. Endophyte colonization was positively correlated with stand density and was reduced on pines treated with spring water acidified with either sulphuric acid alone or in combination with nitric acid. In contrast, nitric acid alone did not affect endophyte colonization. 37 refs., 2 figs., 5 tabs.
Liu, Yang; Zuo, Shan; Xu, Liwen; Zou, Yuanyuan; Song, Wei
The seeds of plants are carriers of a variety of beneficial bacteria and pathogens. Using the non-culture methods of building 16S rDNA libraries, we investigated the endophytic bacterial communities of seeds of four hybrid maize offspring and their respective parents. The results of this study show that the hybrid offspring Yuyu 23, Zhengdan958, Jingdan 28 and Jingyu 11 had 3, 33, 38 and 2 OTUs of bacteria, respectively. The parents Ye 478, Chang 7-2, Zheng 58, Jing 24 and Jing 89 had 12, 36, 6, 12 and 2 OTUs, respectively. In the hybrid Yuyu 23, the dominant bacterium Pantoea (73.38 %) was detected in its female parent Ye 478, and the second dominant bacterium of Sphingomonas (26.62 %) was detected in both its female (Ye 478) and male (Chang 7-2) parent. In the hybrid Zhengdan 958, the first dominant bacterium Stenotrophomonas (41.67 %) was detected in both the female (Zheng 58) and male (Chang 7-2) parent. The second dominant bacterium Acinetobacter (9.26 %) was also the second dominant bacterium of its male parent. In the hybrid Jingdan 28, the second dominant bacterium Pseudomonas (12.78 %) was also the second dominant bacterium of its female parent, and its third dominant bacterium Sphingomonas (9.90 %) was the second dominant bacterium of its male parent and detected in its female parent. In the hybrid Jingyu 11, the first dominant bacterium Leclercia (73.85 %) was the third dominant bacterium of its male parent, and the second dominant bacterium Enterobacter (26.15 %) was detected in its male parent. As far as we know, this was the first research reported in China on the diversity of the endophytic bacterial communities of the seeds of various maize hybrids with different genotypes.
Zubek, Szymon; Nobis, Marcin; Błaszkowski, Janusz; Mleczko, Piotr; Nowak, Arkadiusz
The fungal root endophyte associations of 16 species from 12 families of plants endemic to the Pamir Alay Mountains of Central Asia are presented. The plants and soil samples were collected in Zeravshan and Hissar ranges within the central Pamir Alay mountain system. Colonization by arbuscular mycorrhizal fungi (AMF) was found in 15 plant species; in 8 species it was of the Arum type and in 4 of the Paris type, while 3 taxa revealed intermediate arbuscular mycorrhiza (AM) morphology. AMF colonization was found to be absent only in Matthiola integrifolia, the representative of the Brassicaceae family. The AM status and morphology are reported for the first time for all the species analyzed and for the genera Asyneuma, Clementsia, and Eremostachys. Mycelia of dark septate endophytes (DSE) accompanied the AMF colonization in ten plant species. The frequency of DSE occurrence in the roots was low in all the plants, with the exception of Spiraea baldschuanica. However, in the case of both low and higher occurrence, the percentage of DSE root colonization was low. Moreover, the sporangia of Olpidium spp. were sporadically found inside the root epidermal cells of three plant species. Seven AMF species (Glomeromycota) found in the trap cultures established with soils surrounding roots of the plants being studied were reported for the first time from this region of Asia. Our results provide information that might well be of use to the conservation and restoration programmes of these valuable plant species. The potential application of beneficial root-inhabiting fungi in active plant protection projects of rare, endemic and endangered plants is discussed.
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Trichoderma harzianum KRL-AG2 (ATCC... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1102 Trichoderma harzianum KRL-AG2... of a tolerance is established for residues of the biofungicide Trichoderma harzianum KRL-AG2...
Okeke, Benedict C
Availability, cost, and efficiency of microbial enzymes for lignocellulose bioconversion are central to sustainable biomass ethanol technology. Fungi enriched from decaying biomass and surface soil mixture displayed an array of strong cellulolytic and xylanolytic activities. Strains SG2 and SG4 produced a promising array of cellulolytic and xylanolytic enzymes including β-glucosidase, usually low in cultures of Trichoderma species. Nucleotide sequence analysis of internal transcribed spacer 2 (ITS2) region of rRNA gene revealed that strains SG2 and SG4 are closely related to Trichoderma inhamatum, Trichoderma piluliferum, and Trichoderma aureoviride. Trichoderma sp. SG2 crude culture supernatant correspondingly displayed as much as 9.84 ± 1.12, 48.02 ± 2.53, and 30.10 ± 1.11 units mL(-1) of cellulase, xylanase, and β-glucosidase in 30 min assay. Ten times dilution of culture supernatant of strain SG2 revealed that total activities were about 5.34, 8.45, and 2.05 orders of magnitude higher than observed in crude culture filtrate for cellulase, xylanase, and β-glucosidase, respectively, indicating that more enzymes are present to contact with substrates in biomass saccharification. In parallel experiments, Trichoderma species SG2 and SG4 produced more β-glucosidase than the industrial strain Trichoderma reesei RUT-C30. Results indicate that strains SG2 and SG4 have potential for low cost in-house production of primary lignocellulose-hydrolyzing enzymes for production of biomass saccharides and biofuel in the field.
Full Text Available Various fungal strains belonging to genus Trichoderma act as biological control agents for soil born plant pathogens. Two new strains of Trichoderma harzianum (T.h. and Trichoderma viride (T.v. were isolated from forest soils in Ilfov county and their morphological aspects, enzymatic and antagonistic activity were examined. Current chemical fungicides had constantly, in time, less influence on pathogens due to their diversity, adaptability and increasing resistance.The paper present the morphological characterization of two strains of Trichoderma isolated from forest soils. Growth rate was higher in strain T.v.SP456 (0,675mm/h than in strain T.h.P8 (0,505mm/h when fungi were grown on Czapek culture medium.Morphological description is completed with photographs of colonies in Petri plates and microscopical aspects of fungal structures belonging to Trichoderma strains SP456 and P8.Comparative aspects concerning the level of main enzymes released by T.h. isolate P8 and T.v.SP456 in liquid culture media showed differences as a function of genetic structure of each fungal isolate. The optimum culture media for inducing peroxidase, polyphenol-oxidase, β-1,3-glucanase activity in T.v.SP456 isolate was Czapek and PDA for phenil-alanin-ammonium-oxidase and chitinase. T.v.SP456 was more efficient than T.h.P8 concerning enzymes activity.The interaction between Trichoderma fungal strains SP456 and P8 and strawberry plant pathogen strains, three belonging to Botrytis cinerea (S1, P1, P2 and one to Phytophtora spp. were examined, also. Both Trichoderma strains act as mycoparasites for plant pathogens. The inhibition percent of radial growth was higher for T.v.SP456 when compared with T.h.P8 for almost all pathogenic isolates.
WIWIK EKO WIDAYATI
Full Text Available Endophytic bacteria live in plant host tissues without causing any symptoms. The aim of this study was to examine the indigenous endophytic bacteria on sugarcane plantlets produced from the young leaf cells by using tissue culture techniques. To detect the existence of endophytic bacteria in the plantlet tissue, a series of molecular method based on PCR were applied by using ribosomal intergenic spacer (RIS primer followed by 16S rDNA partial sequence and single strand conformation polymorphism (SCCP. The results showed that the molecular method could detect the existence of bacteria in the tissues. Using the same methods, the bacteria were also found in other developmental stages of sugarcane (explants, differentiated tissues and callus.
Gouda, Sushanto; Das, Gitishree; Sen, Sandeep K.; Shin, Han-Seung; Patra, Jayanta Kumar
Endophytes are an endosymbiotic group of microorganisms that colonize in plants and microbes that can be readily isolated from any microbial or plant growth medium. They act as reservoirs of novel bioactive secondary metabolites, such as alkaloids, phenolic acids, quinones, steroids, saponins, tannins, and terpenoids that serve as a potential candidate for antimicrobial, anti-insect, anticancer and many more properties. While plant sources are being extensively explored for new chemical entities for therapeutic purposes, endophytic microbes also constitute an important source for drug discovery. This review aims to comprehend the contribution and uses of endophytes as an impending source of drugs against various forms of diseases and other possible medicinal use. PMID:27746767
Affina-Eliya, A. A.; Noraini, T.; Nazlina, I.; Ruzi, A. R.
Four species on genus Diplazium namely Diplazium tomentosum, D. sorzogonense, D. asperum and D. accedens of Peninsular Malaysia were studied for presence of fungal endophyte. The objective of this study is to characterize fungal endophytes in the rhizome of four Diplazium species. The rhizome was surface sterilized and incubated to isolate fungal endophytes. Characterization of the colonies was performed by macroscopic morphological, microscopic identification, types of hyphae and mycelium, and spore structure. For isolation that produces spores, the structure of conidiophores and conidia were identified. From this study, four fungal have been isolated and determined as Aspergillus sp. (isolates AE 1), Aspergillus fumigatus (isolates AE 2), Aspergillus versicolor (isolates AE 3) and Verticillium sp. (isolates AE 4). The fungal isolates from this study were classified from the same family Moniliaceae.
Full Text Available Endophytes are an endosymbiotic group of microorganisms that colonize in plants and microbes that can be readily isolated from any microbial or plant growth medium. They act as reservoirs of novel bioactive secondary metabolites, such as alkaloids, phenolic acids, quinones, steroids, saponins, tannins, and terpenoids that serve as a potential candidate for antimicrobial, anti-insect, anticancer and many more properties. While plant sources are being extensively explored for new chemical entities for therapeutic purposes, endophytic microbes also constitute an important source for drug discovery. This review aims to comprehend the contribution and uses of endophytes as an impending source of drugs against various forms of diseases and other possible medicinal use.
Chagnon, Pierre-Luc; U'Ren, Jana M; Miadlikowska, Jolanta; Lutzoni, François; Arnold, A Elizabeth
Understanding the factors that shape community assembly remains one of the most enduring and important questions in modern ecology. Network theory can reveal rules of community assembly within and across study systems and suggest novel hypotheses regarding the formation and stability of communities. However, such studies generally face the challenge of disentangling the relative influence of factors such as interaction type and environmental conditions on shaping communities and associated networks. Endophytic and endolichenic symbioses, characterized by microbial species that occur within healthy plants and lichen thalli, represent some of the most ubiquitous interactions in nature. Fungi that engage in these symbioses are hyperdiverse, often horizontally transmitted, and functionally beneficial in many cases, and they represent the diversification of multiple phylogenetic groups. We evaluated six measures of ecological network structure for >4100 isolates of endophytic and endolichenic fungi collected systematically from five sites across North America. Our comparison of these co-occurring interactions in biomes ranging from tundra to subtropical forest showed that the type of interactions (i.e., endophytic vs. endolichenic) had a much more pronounced influence on network structure than did environmental conditions. In particular, endophytic networks were less nested, less connected, and more modular than endolichenic networks in all sites. The consistency of the network structure within each interaction type, independent of site, is encouraging for current efforts devoted to gathering metadata on ecological network structure at a global scale. We discuss several mechanisms potentially responsible for such patterns and draw attention to knowledge gaps in our understanding of networks for diverse interaction types.
Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.A eficácia de seis produtos comerciais à base de Trichoderma (PCT no controle da podridão-radicular-seca do feijoeiro (PRS foi avaliada em condições de campo. Três PCT, usados no tratamento de sementes ou aplicados no sulco de plantio, aumentaram a emergência das plântulas tanto quanto o fungicida fludioxonil. A incidência de PRS não foi afetada, mas todos os PCT e o fludioxonil reduziram a severidade em relação à testemunha. A aplicação de produtos à base de Trichoderma spp. foi tão eficaz quanto o fludioxonil no manejo da PRS.
Lopez-Quintero, C.A.; Atanasova, L.; Franco-Molano, A.E.; Gams, W.; Komon-Zelazowska, M.; Theelen, B.; Muller, W.H.; Boekhout, T.; Druzhinina, I.
The diversity of Trichoderma (Hypocreales, Ascomycota) colonizing leaf litter as well as the rhizosphere of Garcinia macrophylla (Clusiaceae) was investigated in primary and secondary rain forests in Colombian Amazonia. DNA barcoding of 107 strains based on the internal transcribed spacers 1 and 2 (
Full Text Available Knowledge on the genetic basis underlying interactions between beneficial bacteria and woody plants is still very limited, and totally absent in the case of olive. We aimed to elucidate genetic responses taking place during the colonization of olive roots by the native endophyte Pseudomonas fluorescens PICF7, an effective biocontrol agent against Verticillium wilt of olive. Roots of olive plants grown under non-gnotobiotic conditions were collected at different time points after PICF7 inoculation. A Suppression Subtractive Hybridization cDNA library enriched in induced genes was generated. Quantitative real time PCR (qRT-PCR analysis validated the induction of selected olive genes. Computational analysis of 445 olive ESTs showed that plant defence and response to different stresses represented nearly 45% of genes induced in PICF7-colonized olive roots. Moreover, quantitative real-time PCR (qRT-PCR analysis confirmed induction of lipoxygenase, phenylpropanoid, terpenoids and plant hormones biosynthesis transcripts. Different classes of transcription factors (i.e., bHLH, WRKYs, GRAS1 were also induced. This work highlights for the first time the ability of an endophytic Pseudomonas spp. strain to mount a wide array of defence responses in an economically-relevant woody crop such as olive, helping to explain its biocontrol activity.
Frosty pod rot (FPR), caused by Moniliophthora roreri is responsible for significant losses in Theobroma cacao. Due to the limited options for FPR management, biological control methods using Trichoderma are being studied. Combinations of three formulations and two Trichoderma isolates were studied ...
Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A.; van Wees, Saskia C M
The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the ph
ZHU Ting-heng; WANG Wei-xia; WANG Chang-chun; YANG Rui-qin; CAI Xin-zhong
@@ Fusarium moniliforme Sheld. is a rice pathogenic fungus and causes the disease called Bakanae,which has increasingly damaged rice production in the recent years. Trichoderma spp. has been one of the most widely used biological control agent of plant disease. By geneticaly labelling F. moniliforme with the GFP reporter gene, we have studied the antagonistic action of Trichoderma viride against this pathogenic fungus.
Woo S L; Di Benedetto P; Senatore M; Abadi K; Gigante S; Soriente I; Ferraioli S; Scala F; Lorito M
@@ In the late 1980's the development of a severe epidemic of green mold caused by Trichoderma spp.was noted in the commercial production of Agaricus bisporus (champignon) in the United Kingdom,North America, Spain and Holland, which caused extensive economic losses. The parasitic fungi isolated from the edible mushroom belonged to four biotypes, Thl, Th2, Th3 and Th4 of T.harzianum. However, among these biotypes, only Th2 (since classified as T. aggressivum f.europaeum) and Th4 (T. aggressivum f. aggressivum) were identified as the fungi causing problems in Agaricus production. In general, mushroom compost hosts both aggressive and innocuous isolates of Trichoderma, which are not morphologically distinguishable. About four years ago, a problem with green mold became apparent in the production of Pleurotus ostreatus in Northern Italy,which eventually developed to a crisis situation in the South two years later and threatened to seriously compromise the Pleurotus market. This study was initiated to: isolate and identify the aggressive fungi, then morphologically, physiologically and genetically characterize the isolates, determine the source and phases of infection, and study methods of control. Samples were obtained from different phases of compost preparation at the locality of a major producer and supplier of compost to the mushroom industry in Southern Italy, and microbial counts were conducted. Although the presence of Trichoderma was detected in the initial stages of composting, this value was reduced to zero from the phase of pasteurization to seeding with Pleurotus. Trichoderma infestations were noted in the packaged Pleurotus bales at various times during the incubation phase (7-15 days after seeding) and after shipping to the mushroom greenhouses, where the pathogen infestations greatly reduced the quality and quantity of the mushroom yield, as well as the number of potential harvest cycles.Preliminary results from the morphological and genetic
Gary E Harmant; James Lynch; Matteo Lorito
@@ Trichoderma spp. probably have a role in remediation of polluted soils and waters. Highly rhizosphere competent strains persist on roots for an extended period of time (at least months) and continuously interact with the plants. They can increase general plant and root growth and increase uptake of a variety of materials. This makes the Trichoderma-plant interaction highly attractive for use in phytoextraction technologies. Moreover, Trichoderma spp. are resistant to a wide range of toxic compounds and can degrade some of these. One highly attractive target for remediation are soils that are polluted with cyanide and metallocyanides. Shrub willows (genus Salix) have been shown to take up and degrade these compounds by unknown mechanisms. Thus, they remove these compounds from soil but there are no cyanide residues in the plants. Similarly, Trichoderma spp. degrade free cyanide via production of extracellular enzymes and take up and then degrade metallocyanides such as Prussian blue. The willow-Trichoderma system therefore provides a plant-microbe system for degradation of these toxic compounds. The fungi also can be used directly in remediation strategies; for example,they degrade polyphenols such as those found in large quantities in waste water from production of olive oil. Thus, the abilities of the fungi to interact and enhance plant growth, their ability to grow in the presence of toxicants and their enzymatic abilities to degrade polluting substances provide a number of opportunities for either plant-microbe or pure fungal systems to remove pollutants from lands and waters.
Ruocco M; Ferraioli S; Scala F; Lorito M; Pane F; Ritieni A; Lanzuise S; Ambrosino P; Marra R; Woo S L; Ciliento R; Soriente I
@@ Fusarium spp. are pathogens of many important agricultural crops, and are often strong mycotoxin producers. Fusarium proliferatum, in particular, causes disease in cereals and secretes the toxin Beauvaricin that contaminates livestock feed and cereals, producing a variety of toxicity symptoms ranging from poor weight gain to mortality. Beauvaricin is a cyclodepsipeptide and acts as a potent mycotoxin known to have insecticidal properties. This compound is highly toxic to human cell lines,where it induces apoptosis and specifically inhibits cholesterol acetyltransferase. Nothing is known about the role of this mycotoxin during the interaction of F. proliferatum with other microorganisms, including the fungal antagonists Trichoderma spp. In vitro tests have demonstrated that the antagonistic and mycoparasitic activity of Trichoderma is not inhibited by the presence of Beauvaricin at concentrations up to 10 mg/kg in the substrate. In vivo biocontrol assays on barley and wheat with Trichoderma against F. proliferatum isolates, producing and non-producing Beauvaricin, confirmed the ability of the antagonist to control this pathogen in all cases. Also Trichoderma culture filtrates obtained in conditions that promote _Cell Wall _Degrading Enzyme (CWDE) secretion, were able to inhibit spore germination of different F. proliferatum isolates.These results suggest the possibility of using Trichoderma and/or its metabolites to control contaminants of livestock feed by mycotoxin-producing Fusarium.
Rai, Shalini; Kashyap, Prem Lal; Kumar, Sudheer; Srivastava, Alok Kumar; Ramteke, Pramod W
Microsatellites provide an ideal molecular markers system to screen, characterize and evaluate genetic diversity of several fungal species. Currently, there is very limited information on the genetic diversity of antagonistic Trichoderma species as determined using a range of molecular markers. In this study, expressed and whole genome sequences available in public database were used to investigate the occurrence, relative abundance and relative density of SSRs in five different antagonistic Trichoderma species: Trichoderma atroviride, T. harzianum, T. reesei, T. virens and T. asperellum. Fifteen SSRs loci were used to evaluate genetic diversity of twenty isolates of Trichoderma spp. from different geographical regions of India. Results indicated that relative abundance and relative density of SSRs were higher in T. asperellum followed by T. reesei and T. atroviride. Tri-nucleotide repeats (80.2%) were invariably the most abundant in all species. The abundance and relative density of SSRs were not influenced by the genome sizes and GC content. Out of eighteen primer sets, only 15 primer pairs showed successful amplification in all the test species. A total of 24 alleles were detected and five loci were highly informative with polymorphism information content values greater than 0.40, these markers provide useful information on genetic diversity and population genetic structure, which, in turn, can exploit for establishing conservation strategy for antagonistic Trichoderma isolates.
Joshi, B B; Vishwakarma, M P; Bahukhandi, D; Bhatt, R P
Two species of Trichoderma i.e. T. harzianum and T. viride have been isolated from the soil samples collected from the higher altitude (2000-3500 m) of Garhwal Himalayan region in India. The two species were grown in Petri plates on TSM agar media and it was also observed that the optimum temperature and pH for Trichoderma growth was 30 degrees C and 5.5 respectively. When incubated on TSM agar medium at 4 degrees C, the fungus grew normally with heavy induced sporulation within three weeks of incubation. Induction of sporulation on exposure to low temperature appeared to be strategies for survival of these species in extreme cold environment temperature 4 to 5 degrees C. Antifungal activities of the two species of Trichoderma were demonstrated with phytopathogenic fungi in dual cultures. The antifungal metabolites produced by Trichoderma spp., diffusible as well as volatile, caused abnormalities in pathogenic fungi. Plant growth promotion of Trichoderma spp. was also shown through plant analysis in greenhouse.
Qin, W T; Zhuang, W Y
Collections of hypocrealean fungi found on decaying wood in subtropical regions of China were examined. Two new species, Trichoderma confluens and T. hubeiense, were discovered and are described. Trichoderma confluens is characterized by its widely effuse to rarely pulvinate, yellow stromata with densely disposed yellowish brown ostioles, simple acremonium- to verticillium-like conidiophores, hyaline conidia and multiform chlamydospores. Trichoderma hubeiense has pulvinate, grayish yellow stromata with brownish ostioles, trichoderma- to verticillium-like conidiophores and hyaline conidia. The phylogenetic positions of the two fungi were investigated based on sequence analyses of RNA polymerase II subunit b and translation elongation factor 1-α genes. The results indicate that T. confluens belongs to the Hypocreanum clade and is associated with but clearly separated from T. applanatum and T. decipiens. Trichoderma hubeiense belongs to the Polysporum clade and related to T. bavaricum but obviously differs from other members of the clade in sequence data. Morphological distinctions between the new species and their close relatives are noted and discussed.
Qin, Junhua; Gao, Yuan; Liu, Hui; Zhou, Yong; Ren, Anzhi; Gao, Yubao
It is well-documented that endophytes can enhance the resistance of agronomical grasses, such as tall fescue and perennial ryegrass to herbivory. For native grasses, however, the related reports are limited, and the conclusions are variable. Achnatherum sibiricum is a grass native to the Inner Mongolian steppe. This grass is highly infected by endophytes but does not produce detectable endophyte-related alkaloids known under normal conditions. In this study, the contributions of endophytes to the resistance of A. sibiricum to Locusta migratoria were studied. We found that locusts preferred EF (endophyte-free) plants to EI (endophyte-infected) plants, and the weight of locusts fed on EI plants was significantly lower than those fed on EF plants. Hence, endophyte infection significantly enhanced the resistance of the host to L. migratoria. Endophyte infection significantly decreased the concentration of soluble sugar and amino acids while significantly increased the concentration of total phenolic content, and these metabolites may contribute to herbivore resistance of the host. The clipping treatment further strengthened the locust resistance advantage of EI over EF plants. After clipping, the weight of the locusts fed on EI plants significantly decreased compared with those fed on unclipped plants, whereas the weight of the locusts fed on EF plants increased significantly. The results suggested that endophyte infection could increase herbivore resistance while decreasing the tolerance of the host grass by mechanisms apart from endophyte-conferred alkaloid defense. PMID:28018319
Full Text Available It is well-documented that endophytes can enhance the resistance of agronomical grasses, such as tall fescue and perennial ryegrass to herbivory. For native grasses, however, the related reports are limited, and the conclusions are variable. Achnatherum sibiricum is a grass native to the Inner Mongolian steppe. This grass is highly infected by endophytes but does not produce detectable endophyte-related alkaloids known under normal conditions. In this study, the contributions of endophytes to the resistance of A. sibiricum to Locusta migratoria were studied. We found that locusts preferred EF (endophyte-free plants to EI (endophyte-infected plants, and the weight of locusts fed on EI plants was significantly lower than those fed on EF plants. Hence, endophyte infection significantly enhanced the resistance of the host to L. migratoria. Endophyte infection significantly decreased the concentration of soluble sugar and amino acids while significantly increasing the concentration of total phenolic content, and these metabolites may contribute to herbivore resistance of the host. The clipping treatment further strengthened the locust resistance advantage of EI over EF plants. After clipping, the weight of the locusts fed on EI plants significantly decreased compared with those fed on unclipped plants, whereas the weight of the locusts fed on EF plants increased significantly. The results suggested that endophyte infection could increase herbivore resistance while decreasing the tolerance of the host grass by mechanisms apart from endophyte-conferred alkaloid defense.
Shi, Yingwu; Lou, Kai; Li, Chun
Very little is known about the physiological interactions between plants and endophytic bacteria. We investigated the impact of three endophytic bacteria, Bacillus pumilus 2-1, Chryseobacterium indologene 2-2, and Acinetobacter johnsonii 3-1, on the photosynthetic capacity and growth of sugar beet. Endophyte-free plants were obtained first and infected with the bacteria. Measurements of total chlorophyll content revealed very significant differences between endophyte-free beet plants and some infected by endophytic bacteria. The maximum photochemical yield (Fv/Fm) was used to determine any photosynthetic effect on plants caused by biotic or abiotic factors. After 30 days of growth, there was significantly higher Fv/Fm for endophyte-infected than endophyte-free plants. The light response curves of beet showed that photosynthetic capacity was significantly increased in endophyte-infected plants. Photosynthesis of endophyte-free plants was saturated at 1,300 micromol m(-2) s(-1), whereas endophyte-infected plants were not saturated at the irradiance used. The effect seemed to be due to promotion of electron transport in the thylakoid membranes. Promotion of photosynthetic capacity in sugar beet was due to increased chlorophyll content, leading to a consequent increased carbohydrate synthesis. It is possible that the increased maximum yield of photosynthesis in sugar beet was promoted by phytohormones and produced by the bacteria.
Ambrose, Karen V; Tian, Zipeng; Wang, Yifei; Smith, Jordan; Zylstra, Gerben; Huang, Bingru; Belanger, Faith C
Epichloë spp. are symbiotic fungal endophytes of many cool season grasses. The presence of the fungal endophytes often confers insect, drought, and disease tolerance to the host grasses. The presence of the fungal endophytes within the host plants does not elicit host defense responses. The molecular basis for this phenomenon is not known. Epichloë festucae, the endophyte of Festuca rubra, expresses a salicylate hydroxylase similar to NahG from the bacterium Pseudomonas putida. Few fungal salicylate hydroxylase enzymes have been reported. The in planta expression of an endophyte salicylate hydroxylase raised the possibility that degradation of plant-produced salicylic acid is a factor in the mechanism of how the endophyte avoids eliciting host plant defenses. Here we report the characterization of the E. festucae salicylate hydroxylase, designated Efe-shyA. Although the fungal enzyme has the expected activity, based on salicylic acid levels in endophyte-free and endophyte-infected plants it is unlikely that expression of the endophyte salicylate hydroxylase is a factor in the lack of a host defense response to the presence of the fungal endophyte.
Rajala, Tiina; Velmala, Sannakajsa M; Vesala, Risto; Smolander, Aino; Pennanen, Taina
This study investigated fungal endophytes in the needles of Norway spruce (Picea abies) cuttings in relation to host tree growth. We also determined the prevalence of endophytes in needles incubated for six months. The cuttings originated from clonal origins showing slow- and fast-growth in long-term field trials but the heritable differences in growth rate were not yet detected among the studied cutting. Endophytes were isolated from surface-sterilized needles with culture-free DNA techniques. No significant differences were observed between endophyte communities of slow- and fast-growing clonal origins. However, the endophyte community correlated with the current growth rate of cuttings suggesting that endophytes reflect short- rather than long-term performance of a host. The concentration of condensed tannins was similar in slow- and fast-growing clonal origins but it showed a negative relationship with endophyte species richness, implying that these secondary compounds may play an important role in spruce tolerance against fungal infections. More than a third of endophyte species were detected in both fresh and decomposing needles, indicating that many needle endophytes are facultative saprotrophs. Several potentially pathogenic fungal species were also found within the community of saprotrophic endophytes.
Huang, Yu-Ling; Devan, M M Nandi; U'Ren, Jana M; Furr, Susan H; Arnold, A Elizabeth
Plants in all terrestrial ecosystems form symbioses with endophytic fungi that inhabit their healthy tissues. How these foliar endophytes respond to wildfires has not been studied previously, but is important given the increasing frequency and intensity of severe wildfires in many ecosystems, and because endophytes can influence plant growth and responses to stress. The goal of this study was to examine effects of severe wildfires on endophyte communities in forest trees, with a focus on traditionally fire-dominated, montane ecosystems in the southwestern USA. We evaluated the abundance, diversity, and composition of endophytes in foliage of Juniperus deppeana (Cupressaceae) and Quercus spp. (Fagaceae) collected contemporaneously from areas affected by recent wildfire and paired areas not affected by recent fire. Study sites spanned four mountain ranges in central and southern Arizona. Our results revealed significant effects of fires on endophyte communities, including decreases in isolation frequency, increases in diversity, and shifts in community structure and taxonomic composition among endophytes of trees affected by recent fires. Responses to fire were similar in endophytes of each host in these fire-dominated ecosystems and reflect regional fire-return intervals, with endophytes after fire representing subsets of the regional mycoflora. Together, these findings contribute to an emerging perspective on the responses of diverse communities to severe fire, and highlight the importance of considering fire history when estimating endophyte diversity and community structure for focal biomes.
Afzal, Muhammad; Khan, Qaiser M; Sessitsch, Angela
Recently, there has been an increased effort to enhance the efficacy of phytoremediation of contaminated environments by exploiting plant-microbe interactions. The combined use of plants and endophytic bacteria is an emerging approach for the clean-up of soil and water polluted with organic compounds. In plant-endophyte partnerships, plants provide the habitat as well as nutrients to their associated endophytic bacteria. In response, endophytic bacteria with appropriate degradation pathways and metabolic activities enhance degradation of organic pollutants, and diminish phytotoxicity and evapotranspiration of organic pollutants. Moreover, endophytic bacteria possessing plant growth-promoting activities enhance the plant's adaptation and growth in soil and water contaminated with organic pollutants. Overall, the application of endophytic bacteria gives new insights into novel protocols to improve phytoremediation efficiency. However, successful application of plant-endophyte partnerships for the clean-up of an environment contaminated with organic compounds depends on the abundance and activity of the degrading endophyte in different plant compartments. Although many endophytic bacteria have the potential to degrade organic pollutants and improve plant growth, their contribution to enhance phytoremediation efficiency is still underestimated. A better knowledge of plant-endophyte interactions could be utilized to increase the remediation of polluted soil environments and to protect the foodstuff by decreasing agrochemical residues in food crops.
Dirihan, Serdar; Helander, Marjo; Väre, Henry; Gundel, Pedro E.; Garibaldi, Lucas A.; Irisarri, J. Gonzalo N.; Saloniemi, Irma; Saikkonen, Kari
Polyploidy and symbiotic Epichloë fungal endophytes are common and heritable characteristics that can facilitate environmental range expansion in grasses. Here we examined geographic patterns of polyploidy and the frequency of fungal endophyte colonized plants in 29 Festuca rubra L. populations from eight geographic sites across latitudes from Spain to northernmost Finland and Greenland. Ploidy seemed to be positively and negatively correlated with latitude and productivity, respectively. However, the correlations were nonlinear; 84% of the plants were hexaploids (2n = 6x = 42), and the positive correlation between ploidy level and latitude is the result of only four populations skewing the data. In the southernmost end of the gradient 86% of the plants were tetraploids (2n = 4x = 28), whereas in the northernmost end of the gradient one population had only octoploid plants (2n = 8x = 56). Endophytes were detected in 22 out of the 29 populations. Endophyte frequencies varied among geographic sites, and populations and habitats within geographic sites irrespective of ploidy, latitude or productivity. The highest overall endophyte frequencies were found in the southernmost end of the gradient, Spain, where 69% of plants harbored endophytes. In northern Finland, endophytes were detected in 30% of grasses but endophyte frequencies varied among populations from 0% to 75%, being higher in meadows compared to riverbanks. The endophytes were detected in 36%, 30% and 27% of the plants in Faroe Islands, Iceland and Switzerland, respectively. Practically all examined plants collected from southern Finland and Greenland were endophyte-free, whereas in other geographic sites endophyte frequencies were highly variable among populations. Common to all populations with high endophyte frequencies is heavy vertebrate grazing. We propose that the detected endophyte frequencies and ploidy levels mirror past distribution history of F. rubra after the last glaciation period, and local
... have control of the commodity, such person must have complete decision-making authority regarding...-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 General § 1421.6 Beneficial interest. (a) To be eligible to receive marketing assistance loans and loan deficiency payments, a...
Corzo, N; Alonso, J L; Azpiroz, F; Calvo, M A; Cirici, M; Leis, R; Lombó, F; Mateos-Aparicio, I; Plou, F J; Ruas-Madiedo, P; Rúperez, P; Redondo-Cuenca, A; Sanz, M L; Clemente, A
Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits.
Rickman, Doug L.
Natural feedstocks used for any process are intrinsically variable. They may also contain deleterious components or low concentrations of desired fractions. For these three reasons it is standard industrial practice to beneficiate feedstocks. This is true across all industries which trans-form raw materials into standardized units. On the Moon there are three natural resources: vacuum, radiation and regolith. To utilize in situ resources on the Moon it is reasonable to presume some beneficiation of the regolith (ground rock) resource will be desirable if not essential. As on Earth, this will require fundamental understanding of the physics and chemistry of the relevant processes, which are exceeding complex in detail. Further, simulants are essential test articles for evaluation of components and systems planned for lunar deployment. Simulants are of course made from geologic feedstocks. Therefore, there is variation, deleterious components and incorrect concentrations of desired fractions in the feedstocks used for simulants. Thus, simulant production can benefit from beneficiation of the input feedstocks. Beneficiation of geologic feedstocks is the subject of extractive metallurgy. Clearly, NASA has two discrete interests pertaining to the science and technology of extractive metallurgy.
Pieterse, C.M.J.; Zamioudis, C.; Berendsen, R.L.; Weller, D.M.; Van Wees, S.C.M.; Bakker, P.A.H.M.
Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of patho
Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A; Van Wees, Saskia C M
The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.
Yanqing WU; Tiantian LIU; Xueli HE
Biodiversity of arbuscular mycorrhizal colonization and spore density was investigated in 20 desert plants (dominant or common species) collected from different locations of Mu Us Sandy Land of China. We observed three mycorrhizal types including Arum-type, Paris-type, and an intermediate type among the plants. Another type of potentially beneficial fungi associated with roots of all species was also observed, namely, dark septate endophytic fungi (DSEF). Of the 20 sample plants examined, all species were coinfected by the two target fungi (Arbuscular mycorrhizal fungi (AMF) colonization of Salixpsammophila and DSEF colonization of Periploca septum were as low as 4%). Based on this investigation, we speculated that the DSEF are ubiquitous in desert ecosystems and can co-occur with AMF in desert plants, functioning much like mycorrhizal fungi. Further studies will be required to elucidate interactional mechanisms with AMF and the mechanisms operating in desert ecosystem.
Lopes, Fabyano Alvares Cardoso; Steindorff, Andrei Stecca; Geraldine, Alaerson Maia; Brandão, Renata Silva; Monteiro, Valdirene Neves; Lobo, Murillo; Coelho, Alexandre Siqueira Guedes; Ulhoa, Cirano José; Silva, Roberto Nascimento
Some species of Trichoderma have successfully been used in the commercial biological control of fungal pathogens, e.g., Sclerotinia sclerotiorum, an economically important pathogen of common beans (Phaseolus vulgaris L.). The objectives of the present study were (1) to provide molecular characterization of Trichoderma strains isolated from the Brazilian Cerrado; (2) to assess the metabolic profile of each strain by means of Biolog FF Microplates; and (3) to evaluate the ability of each strain to antagonize S. sclerotiorum via the production of cell wall-degrading enzymes (CWDEs), volatile antibiotics, and dual-culture tests. Among 21 isolates, we identified 42.86% as Trichoderma asperellum, 33.33% as Trichoderma harzianum, 14.29% as Trichoderma tomentosum, 4.76% as Trichoderma koningiopsis, and 4.76% as Trichoderma erinaceum. Trichoderma asperellum showed the highest CWDE activity. However, no species secreted a specific group of CWDEs. Trichoderma asperellum 364/01, T. asperellum 483/02, and T. asperellum 356/02 exhibited high and medium specific activities for key enzymes in the mycoparasitic process, but a low capacity for antagonism. We observed no significant correlation between CWDE and antagonism, or between metabolic profile and antagonism. The diversity of Trichoderma species, and in particular of T. harzianum, was clearly reflected in their metabolic profiles. Our findings indicate that the selection of Trichoderma candidates for biological control should be based primarily on the environmental fitness of competitive isolates and the target pathogen.
Rodríguez Peralta, Laura I; Mañas Vera, Ma Reyes; García Delgado, Manuel J; Pérez de la Cruz, Antonio J
Home parenteral nutrition (HPN) improves the quality of life of the patients although it has complications. Catheter-related infections and mechanical complications are the most frequent ones. We report the case of endocarditis over catheter in a man suffering from short bowel and receiving HPN. The special features of the case are firstly the catheter was a remaining fragment on the right atrial and secondly the infection was caused by Trichoderma longibrachiatum, an isolated fact regarding this pathology so far. Conventional surgery was applied to take the catheter out. Staphylococcus epidermidis, Ochrobactrum anthropi and Trichoderma longibrachiatum were isolated from the surgical specimen. The extraction of the infected catheter along with antibiotic therapy led to the complete recovery of the subject. Ochrobactrum anthropi and Trichoderma longibrachiatum are unusual microorganisms but they are acquiring more relevance. Although there is no agreement about intravascular retained catheter management, the most recommended approach consists on monitoring them and removing the device in case of complications.
YU Ze-fen; ZHANG Ke-qin
@@ To study the effect of tobacco growth on Trichoderma population, we investigated the occurrence of Trichoderma species in the rhizosphere of tobacco plant during the period from transplanting (June) to harvesting (October) and measured relative environmental factors. Eleven species of Trichoderma were isolated, among which T. harzianum, T. viride, T. hamatum, T. atroviride, T.longibrachiatum, T. virens, T. koningii were identified, other four species Ty1, Ty2, Ty3, Ty4are new species. Of the species which occurred at high frequencies, T. harzianum and T. hamatum were most abundant in the July and T. viride in the August. The occurrence of the above three abundant species correlates significantly with the developmental phase of tobacco and correlates apparently with the soil moisture content, but not with the temperature. For the other eight species,no obvious correlation was found between the above factors and them.
Szakacs G; Nagy V; Kovacs K
@@ The relationship between taxonomic status of Trichoderma spp., chitinase production in solid substrate fermentation (SSF) on four media and mycoparasitism in dual culture (confrontation assay)against four plant pathogenic fungi was studied. Seventy five Trichoderma isolates belonging to 35species have been screened. The plant pathogenic fungi used in confrontation assay were Botrytis cinerea , Fusarium oxysporum f. sp. dianthi , Rhizoctonia solani and Sclerotinia sclerotiorum . The SSF media contained wheat bran, crude chitin (from crab shells, SIGMA) and salt solutions. The best performing isolates in mycoparasitism tests were Trichoderma flavofuscum, T. harzianum, T.inhamatum, T. koningii and T. strigosum. Some isolates exhibiting good mycoparasitism produced chitinase in SSF only at low or medium level. In contrary there were isolates with excellent extracellular chitinase production but their biocontrol potential did not belong to the leading group.Statistical methods have been used to evaluate the data.
Knapp, D.G.; Kovács, G.M.; Zajta, E.; Groenwald, J.Z.; Crous, P.W.
Dark septate endophytes (DSE) are distributed worldwide as root-colonising fungi, and frequent in environments with strong abiotic stress. DSE is not a taxon, but constitutes numerous fungal taxa belonging to several orders of Ascomycota. In this study we investigate three unidentiﬁed DSE lineages b
Bacon et al. (1977) proposed and Hoveland et al. (1980, 1986) substantiated that impaired health and performance of livestock grazing tall fescue [Lolium arundinaceum S. J. Darbyshire, formerly Festuca arundinacea Schreb.] were associated with the fungal endophyte Neotyphodium coenophialum Glenn, Ha...
Kernaghan, Gavin; Patriquin, Glenn
Fungal root endophytes colonize root tissue concomitantly with mycorrhizal fungi, but their identities and host preferences are largely unknown. We cultured fungal endophytes from surface-sterilized Cenococcum geophilum ectomycorrhizae of Betula papyrifera, Abies balsamea, and Picea glauca from two boreal sites in eastern Canada. Isolates were initially grouped on the basis of cultural morphology and then identified by internal transcribed spacer ribosomal DNA sequencing or by PCR restriction fragment length polymorphism. Phylogenetic analysis of the sequence data revealed 31 distinct phylotypes among the isolates, comprising mainly members of the ascomycete families Helotiaceae, Dermateaceae, Myxotrichaceae, and Hyaloscyphaceae, although other fungi were also isolated. Multivariate analyses indicate a clear separation among the endophyte communities colonizing each host tree species. Some phylotypes were evenly distributed across the roots of all three host species, some were found preferentially on particular hosts, and others were isolated from single hosts only. The results indicate that fungal root endophytes of boreal trees are not randomly distributed, but instead form relatively distinct assemblages on different host tree species.
Lipid bodies are universal components of plant cells and provide a mobilized carbon source for essential biological processes. Plant oils harvested for food and fuel often reside in these lipid bodies. Plants also host diverse populations of endophytic fungi, which easily escape microscopic detect...
Knapp, D G; Kovács, G M; Zajta, E; Groenewald, J Z; Crous, P W
Dark septate endophytes (DSE) are distributed worldwide as root-colonising fungi, and frequent in environments with strong abiotic stress. DSE is not a taxon, but constitutes numerous fungal taxa belonging to several orders of Ascomycota. In this study we investigate three unidentified DSE lineages
Most plants harbor a diverse assemblage of non-mycorrhizal fungal endophytes. These fungi can directly influence the host plant, and can instigate trophic cascades that affect surrounding communities of herbivores, plants, and animals. Despite this, biotic mechanisms that influence assembly of funga...
Full Text Available The objective of this study was to evaluate in vitro the endophytic bacteria resistance to different lead concentrations. The sampling was undertaken in the first half of 2013, when tissue samples of commercial varieties of rice at tillering stage were collected in Montería, Cordoba, Colombia. Each tissue was subjected to surface cleaning. Endophytic bacteria in agar R2A medium were isolated. Population density (CFU/g tissue was determined from each tissue, by direct counting of R2A medium surface. morphotypes were classified by shape, color, size, and appearance. A total of 168 morphotypes were isolated from root, tillers, and leaf of different commercial varieties of rice. The lead resistance test was performed in vitro, to do that, suspensions of endophytic bacteria in log phase were prepared and inoculated in minimal medium with five concentrations of lead as Pb(NO32. The experiment was incubated at 32 °C and agitated at 150 rpm, for five days. Every hour afterstarting the test, turbidimetry measuring at 600 nm was conducted. Results showed the ability of endophytic bacteria to grow at concentrations of 100% of Pb as Pb(NO32. The results of the identification with kit API20E confirmed the presence of Burkholderia cepacia and Pseudomonas putida, which showed resistance to different lead concentrations.
Dhanya N. Nair
Full Text Available Endophytes are microorganisms (bacteria or fungi or actinomycetes that dwell within robust plant tissues by having a symbiotic association. They are ubiquitously associated with almost all plants studied till date. Some commonly found endophytes are those belonging to the genera Enterobacter sp., Colletotrichum sp., Phomopsis sp., Phyllosticta sp., Cladosporium sp., and so forth. Endophytic population is greatly affected by climatic conditions and location where the host plant grows. They produce a wide range of compounds useful for plants for their growth, protection to environmental conditions, and sustainability, in favour of a good dwelling place within the hosts. They protect plants from herbivory by producing certain compounds which will prevent animals from further grazing on the same plant and sometimes act as biocontrol agents. A large amount of bioactive compounds produced by them not only are useful for plants but also are of economical importance to humans. They serve as antibiotics, drugs or medicines, or the compounds of high relevance in research or as compounds useful to food industry. They are also found to have some important role in nutrient cycling, biodegradation, and bioremediation. In this review, we have tried to comprehend different roles of endophytes in plants and their significance and impacts on man and environment.
Weyens, N.; van der Lelie, D.; Artois, T.; Smeets, K.; Taghavi, S.; Newman, L.; Carleer, R.; Vangronsveld, J.
Phytoremediation of volatile organic contaminants often proves not ideal because plants and their rhizosphere microbes only partially degrade these compounds. Consequently, plants undergo evapotranspiration that contaminates the ambient air and, thus, undermines the merits of phytoremediation. Under laboratory conditions, endophytic bacteria equipped with the appropriate degradation pathways can improve in plant degradation of volatile organic contaminants. However, several obstacles must be overcome before engineered endophytes will be successful in field-scale phytoremediation projects. Here we report the first in situ inoculation of poplar trees, growing on a TCE-contaminated site, with the TCE-degrading strain Pseudomonas putida W619-TCE. In situ bioaugmentation with strain W619-TCE reduced TCE evapotranspiration by 90% under field conditions. This encouraging result was achieved after the establishment and enrichment of P. putida W619-TCE as a poplar root endophyte and by further horizontal gene transfer of TCE metabolic activity to members of the poplar's endogenous endophytic population. Since P. putida W619-TCE was engineered via horizontal gene transfer, its deliberate release is not restricted under European genetically modified organisms (GMO) regulations.
Malfanova, Natalia V.
Since global food insecurity is one of the major problems faced by humanity, there is a necessity to increase plant productivity. For this, biofungicides and biofertilizers present an ecologically friendly alternative to their chemical counterparts. Among these bioinoculants, endophytic bacteria wit
Campisano, Andrea; Antonielli, Livio; Pancher, Michael; Yousaf, Sohail; Pindo, Massimo; Pertot, Ilaria
Microbial plant endophytes are receiving ever-increasing attention as a result of compelling evidence regarding functional interaction with the host plant. Microbial communities in plants were recently reported to be influenced by numerous environmental and anthropogenic factors, including soil and pest management. In this study we used automated ribosomal intergenic spacer analysis (ARISA) fingerprinting and pyrosequencing of 16S rDNA to assess the effect of organic production and integrated pest management (IPM) on bacterial endophytic communities in two widespread grapevines cultivars (Merlot and Chardonnay). High levels of the dominant Ralstonia, Burkholderia and Pseudomonas genera were detected in all the samples We found differences in the composition of endophytic communities in grapevines cultivated using organic production and IPM. Operational taxonomic units (OTUs) assigned to the Mesorhizobium, Caulobacter and Staphylococcus genera were relatively more abundant in plants from organic vineyards, while Ralstonia, Burkholderia and Stenotrophomonas were more abundant in grapevines from IPM vineyards. Minor differences in bacterial endophytic communities were also found in the grapevines of the two cultivars.
Kan, van J.A.L.; Shaw, M.W.; Grant-Downton, R.T.
Plant pathology has a long-standing tradition of classifying microbes as pathogens, endophytes or saprophytes. Lifestyles of pathogens are categorized as biotrophic, necrotrophic or hemibiotrophic. Botrytis species are considered by many to be archetypal examples of necrotrophic fungi, with B.¿ciner
Sharma, Tanwi; Kaul, Sanjana; Dhar, Manoj K
Saffron (Crocus sativus) is a medicinally important plant. The Kashmir valley (J&K, India) emblematizes one of the major and quality saffron producing areas in the world. Nonetheless, the area has been experiencing a declining trend in the production of saffron during the last decade. Poor disease management is one of the major reasons for declining saffron production in the area. Endophytes are known to offer control against many diseases of host plant. During the present study, culturable bacterial endophytes were isolated from saffron plant, identified and assessed for plant growth promoting activities. Molecular and phylogenetic analysis grouped the fifty-four bacterial isolates into eleven different taxa, viz. Bacillus licheniformis, B. subtilis, B. cereus, B. humi, B. pumilus, Paenibacillus elgii, B. safensis, Brevibacillus sp., Pseudomonas putida, Staphylococcus hominis and Enterobacter cloacae. The results were also supported with the identification based on BIOLOG system. B. licheniformis was the dominant endophyte in both leaves and corms of saffron. 81 % isolates showed lipase activity, 57 % cellulase, 48 % protease, 38 % amylase, 33 % chitinase and 29 % showed pectinase activity. 24 % of the isolates were phosphate solublizers, 86 % showed siderophore production and 80 % phytohormone production potential. The present repository of well characterized bacterial endophytes of saffron, have plant growth promoting potential which can be explored further for their respective roles in the biology of the saffron plant.
Gomes, R.R.; Glienke, C.; Videira, S.I.R.; Lombard, L.; Groenewald, J.Z.; Crous, P.W.
Diaporthe (Phomopsis) species have often been reported as plant pathogens, non-pathogenic endophytes or saprobes, commonly isolated from a wide range of hosts. The primary aim of the present study was to resolve the taxonomy and phylogeny of a large collection of Diaporthe species occurring on diver
Ergovaline is an ergot alkaloid found in some endophyte-infected ryegrasses and has been implicated in the expression of ergotism-like symptoms of grazing livestock, as well as in the protection of the plant against invertebrate predation and abiotic stresses. These selection pressures have resulted...
Stępniewska, Z; Kuźniar, A
Bioremediation is a technique that uses microbial metabolism to remove pollutants. Various techniques and strategies of bioremediation (e.g., phytoremediation enhanced by endophytic microorganisms, rhizoremediation) can mainly be used to remove hazardous waste from the biosphere. During the last decade, this specific technique has emerged as a potential cleanup tool only for metal pollutants. This situation has changed recently as a possibility has appeared for bioremediation of other pollutants, for instance, volatile organic compounds, crude oils, and radionuclides. The mechanisms of bioremediation depend on the mobility, solubility, degradability, and bioavailability of contaminants. Biodegradation of pollutions is associated with microbial growth and metabolism, i.e., factors that have an impact on the process. Moreover, these factors have a great influence on degradation. As a result, recognition of natural microbial processes is indispensable for understanding the mechanisms of effective bioremediation. In this review, we have emphasized the occurrence of endophytic microorganisms and colonization of plants by endophytes. In addition, the role of enhanced bioremediation by endophytic bacteria and especially of phytoremediation is presented.
Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.;
(root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...
Full Text Available The use of plant growth promoting bacterial inoculants as live microbial biofertilisers provides a promising alternative to chemical fertilisers and pesticides. Inorganic phosphate solubilisation is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilise the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilisation. The study presented here describes the ability of endophytic bacterial isolates to produce gluconic acid, solubilise insoluble phosphate and stimulate the growth of Pea plants (Pisum sativum. This study also describes the genetic systems within three of these endophyte isolates thought to be responsible for their effective phosphate solubilising abilities. The results showed that many of the endophytic isolates produced gluconic acid (14-169 mM and have moderate to high phosphate solubilisation capacities (~ 400-1300 mg L-1. When inoculated to Pea plants grown in sand/soil under soluble phosphate limiting conditions, the endophyte isolates that produced medium to high levels of gluconic acid also displayed enhanced plant growth promotion effects.
Bogner, C.W.; Kamdem, R.S.; Stichtermann, G.; Matthäus, C.; Hölscher, D.; Popp, J.; Proksch, P.; Grundler, F.M.; Schouten, A.
In order to replace particularly biohazardous nematocides, there is a strong drive to finding natural product-based alternatives with the aim of containing nematode pests in agriculture. The metabolites produced by the fungal endophyte Fusarium oxysporum 162 when cultivated on rice media were isolat
Kesting, Julie Regitze; Olsen, Lars; Stærk, Dan;
The endophytic fungus Pestalotiopsis virgatula, derived from the plant Terminalia chebula and previously found to produce a large excess of a single metabolite when grown in the minimal M1D medium, was induced to produce a variety of unusual metabolites by growing in potato dextrose broth medium...
Increasing evidence indicates that plant microbiomes are influence by ecological successes of plant hosts. Further, endophytic microbes such as bacteria and fungi greatly affect plant stress tolerance and are responsible for defensive reaction to several forms of herbivory. What is not yet clear i...
Abreu, L.M.; Phipps, Richard Kerry; Pfenning, L.H.;
Cytosporones O, P and Q, together with the known compounds cytosporones B, C, D, E and dothiorelones A, 13, C. and H were isolated from the ascomycete fungus Cytospora sp. during a chemotaxonomic study Of fungal endophytes belonging to the related genera Cytospora and Phomopsis from Brazil...
Tétard-Jones, Catherine; Edwards, Robert
Herbicide tolerance in crops and weeds is considered to be monotrophic, i.e. determined by the relative susceptibility of the physiological process targeted and the plant's ability to metabolise and detoxify the agrochemical. A growing body of evidence now suggests that endophytes, microbes that inhabit plant tissues and provide a range of growth, health and defence enhancements, can contribute to other types of abiotic and biotic stress tolerance. The current evidence for herbicide tolerance being bitrophic, with both free-living and plant-associated endophytes contributing to tolerance in the host plant, has been reviewed. We propose that endophytes can directly contribute to herbicide detoxification through their ability to metabolise xenobiotics. In addition, we explore the paradigm that microbes can 'prime' resistance mechanisms in plants such that they enhance herbicide tolerance by inducing the host's stress responses to withstand the downstream toxicity caused by herbicides. This latter mechanism has the potential to contribute to the growth of non-target-site-based herbicide resistance in weeds. Microbial endophytes already contribute to herbicide detoxification in planta, and there is now significant scope to extend these interactions using synthetic biology approaches to engineer new chemical tolerance traits into crops via microbial engineering.
Hackbart, H C S; Machado, A R; Christ-Ribeiro, A; Prietto, L; Badiale-Furlong, E
This study evaluated the ability of the microorganisms Rhizopus oryzae (CCT7560) and Trichoderma reesei (QM9414), producers of generally recognized as safe (GRAS) enzymes, to reduce the level of aflatoxins B1, B2, G1, G2, and M1. The variables considered to the screening were the initial number of spores in the inoculum and the culture time. The culture was conducted in contaminated 4 % potato dextrose agar (PDA) medium, and the residual mycotoxins were determined every 24 h by HPLC-FL. The fungus R. oryzae has reduced aflatoxins B1, B2, and G1 in the 96 h and aflatoxins M1 and G2 in the range of 120 h of culture by approximately 100 %. The fungus T. reesei has reduced aflatoxins B1, B2, and M1 in the 96 h and aflatoxin G1 in the range of 120 h of culture by approximately 100 %. The highest reduction occurred in the middle of R. oryzae culture.
Mustafa, Ghulam; Arshad, Muhammad
Industrially important enzymes and microbial biomass proteins have been produced from fungi for more than 50 years. High levels of crude protein as much as 45% are present in fungal biomass with balanced essential amino acids. The aim of this study was to access the potential of Trichoderma harzianum to produce fungal biomass protein from rice polishings. Maximum biomass yield was obtained at 5% (w/v) rice polishings after 72 h of incubation at 28°C at pH 4. Carbon and nitrogen ratio of 20 : 1 gave significantly higher production of fungal biomass protein. The FBP in the 75 L fermenter contained 49.50% crude protein, 32.00% true protein, 19.45% crude fiber, 9.62% ash, 11.5% cellulose content, and 0.325% RNA content. The profile of amino acids of final FBP exhibited that all essential amino acids were present in great quantities. The FBP produced by this fungus has been shown to be of good nutritional value for supplementation to poultry. The results presented in this study have practical implications in that the fungus T. harzianum could be used successfully to produce fungal biomass protein using rice polishings.
Barcellos Fernando Gomes
Full Text Available Crossing experiments via hyphal anastomosis between two strains contrasting for auxotrophic markers of Trichoderma pseudokoningii were conducted to characterize the somatic recombination process in this specie. Four crossings were made and a total of 1052 colonies obtained from conidial suspensions of the heterokaryotic colonies were analyzed. Sixty-eight recombinant colonies, from four growing generations, were analyzed for the auxotrophic markers. Of the 68 colonies analyzed, 58 were stable after four generations and the remainders were unstable, reverting to one of the parentals. Most of the recombinant colonies were unstable through subculture and after four growing generations they showed the leu ino met markers (auxotrophic for leucin, inositol and metionin respectively. The unstable recombinant colonies showed irregular growing borders, sparse sporulation and frequent sector formation. The results suggest the occurrence of recombination mechanisms in the heterokaryon (somatic recombination, different from those described for the parasexual cycle or parameiosis. Therefore, we proposed the ocurrence of nuclei degradation from one parental (non prevalent parental in the heterokaryon and that the resulting chromosomal fragments may be incorporated into whole nuclei of the another parental (prevalent parental. However the parameiosis as originally described cannot be excluded.
Anita Losonczi; George Szakacs; Emilia Csiszar; Outi Kareela
@@ Preparation and bleaching are among the most energy and chemical intensive steps of the traditional cotton finishing. About 75 % of the organic pollutants arising from textile finishing are derived from the preparation of cotton goods. Biopreparation may be a valuable and environmentally friendly alternative to harsh alkaline chemicals for preparing of cotton. Different enzymes i. e. cellulases,pectinases, lipases and proteases have been tested for biopreparation. Many papers have been published how enzymes effect on the properties of cotton fabrics in respect to their effectiveness to replace alkaline scouring and how enzymes modify the various cell wall components of cotton fibers. However,very few data have been reported on bleachability and dyeing behavior of the bioscoured fabrics. In this work an acidic cellulase (Celluclast 1.5 L, Trichoderma reesei origin), an acidic pectinasehemicellulase (Viscozyme 120 L , Aspergillus aculeatus ) and a cellulase-free xylanase (Pulpzyme HC,Bacillus sp. ) enzymes were used for bioscouring of greige cotton fabric. Selected properties of the pretreated samples, which are important for effective dyeing, are characterized in detail. Effect of hydrogen peroxide bleaching, applied subsequent to the biopretreatment on the bleachability and dyeing properties of the samples is also elucidated. A reactive dye was used at four different concentrations to compare the dyeing behavior of biopretreated as well as biopretreated and subsequently bleached cotton fabrics with that of the alkaline scoured as well as alkaline scoured and bleached fabrics, respectively. Color evenness and uniformity, and wash fastness properties of the dyed samples are also determined.
Linda Gordon Hjeljord; Arne Tronsmo
@@ The effect of preliminary nutrient activation on the ability of conidia of the antagonist Trichoderma harzianum P1 (ThP1) to suppress Botrytis cinerea was investigated in laboratory, greenhouse and field trials. Preliminary nutrient activation at 21 ℃ accelerated subsequent germination of the antagonist at temperatures from 9 ℃ to 21 ℃; at ≥ 18 ℃ the germination time of preactivated ThP1conidia did not differ significantly from that of B. cinerea. When coinoculated with B. cinerea,concentrated inocula of preactivated but ungerminated ThP1 conidia reduced in vitro germination of the pathogen by ≥ 87 % at 12 ℃ to 25 ℃; initially-quiescent conidia achieved this level of suppression only at 25 ℃. Application of quiescent ThP1 conidia to detached strawberry flowers in moist chambers reduced infection by B. cinerea by ≥85 % at 24 ℃ , but only by 35 % at 12 ℃. Preactivated conidia reduced infection by ≥60% at 12 ℃. Both quiescent and preactivated conidia significantly reduced latent infection in greenhouse-grown strawberries at a mean temperture of 19 ℃, while only preactivated conidia were effective in the field at a mean temperature of 14 ℃ on the day of treatment application.
Sanz L; Hermosa M R; González F J; Monte E
@@ Species of the fungus Trichoderma, a genus of Hyphomycetes, are ubiquitous in the environment, but especially in soil. They have been used in a wide range of commercial applications including the production of hydrolases and in the biological control of plant diseases. A fundamental part of the Trichoderma antifungal system consists of a series of genes coding for a surprising variety of extracellular cell wall degrading enzymes (CWDE).Characterisation and identification of strains at the species level is the first step in utilizing the full potential of fungi in specific applications. One aim when isolating Trichoderma strains is to identify those which can be used in new agricultural and industrial applications. In the past it was not uncommon that biocontrol strains were defined as T. harzianum Rifai, due to the limited classification system of the genus Trichoderma. In recent years, several PCR-based molecular techniques have been used to detect and discriminate among microorganisms. Sequence analysis of the ITS regions of the ribosomal DNA and gene fragments as those corresponding to tef1 gene have been helpful in the neotypification, description and characterization of species in the genus Trichoderna.Another useful method for the identification of Trichoderma strains is the randomly amplified polymorphic DNA (RAPD) technique.Isozyme polymorphisms evaluation of five putative extracellular lytic enzymes loci (β-1,3-glucanase, β-1,6-glucanase, cellulase, chitinase and protease antivities) were carried out using representative strains of defined molecular groups. CWDE groupings obtained from biocontrol strains are discussed in relation to their phylogenetic location and antifungal activities.Compiling morphological, biochemical and sequence information data into a common database would provide a useful resource that could be used to accurately name new haplotypes identified in the future and correctly place them within the genus Trichoderma.
Dai, Zhi-Cong; Fu, Wei; Wan, Ling-Yun; Cai, Hong-Hong; Wang, Ning; Qi, Shan-Shan; Du, Dao-Lin
The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP) effects of endophytic bacteria Bacillus sp. on aseptic seedlings of Wedelia trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria, relative change ratios of the clonal traits and the ramets’ growth traits of W. trilobata were significantly greater than those of W. chinensis. Our results indicate that the growth-promoting effects of endophytes may differ between invasive and native clonal plants, and the endophytes of invasive plant may be host-specific to facilitate plant invasion. PMID:27252722
Hema Shenpagam N.*, D. Kanchana Devi ** and Sinduja G.
Full Text Available In the present study, the endophytic actinomycetes were collected from three medicinal plants Azadiracta indica, Ocimum sanctum and Phyllanthus amarus. Endophytic actinomycetes were isolated using different media like Starch casein agar, Starch casein nitrate agar, Actinomycetes isolation agar and Soyabean agar, while it showed more colonies in Starch casein agar. The endophytic actinomycetes were stained and biochemical tests were performed. Antimicrobial compound was purified from the filtrate by ethanol extraction method. Antagonistic activities of endophytic actinomycetes isolates were tested against bacterial pathogens (Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae and Pseudomonas aeruginosa and the fungi Rhizopus. For the selected isolates antibiotic resistance was checked using various antibiotic discs like Amoxycillin, Penicillin, Rifampicin and Ampicillin. The strains which showed efficient antibacterial activity were selected to study the effect of mutation by physical and chemical method. In this study, UV mutated endophytic actinomycetes increase antibiotic production than non-mutated endophytic Actinomycetes, whereas in chemical mutation it does not increase the antibiotic production.
Full Text Available The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP effects of endophytic bacteria Bacillus sp. on aseptic seedlings of W. trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria, relative change ratios of the clonal traits and the ramets' growth traits of W. trilobata were significantly greater than those of W. chinensis. Our results indicate that the growth-promoting effects of endophytes may differ between invasive and native clonal plants, and the endophytes of invasive plant may be host-specific to facilitate plant invasion.
Jorge, Maria de Lurdes Antunes
[ES]Entre los hongos del género Trichoderma se han descrito algunas especies importantes como agentes de biocontrol, tales como las parejas anamorfo/teleomorfo T. harzianum/Hypocrea lixii, T. viride/H. rufa, T. atroviride/H. atroviridis y T. virens/H. virens. Trichoderma tiene una amplia distribución geográfica, está presente en casi todos los suelos y en hábitats diversos (creciendo en madera, corteza, sobre y dentro otros hongos y sustratos innumerables). Por su adaptación a distintos en...
Full Text Available Seed treatment of soybean with Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii and T. pseudokoningii significantly controlled the infection of 30-day-old seedlingsby Maerophomina phaseolina, Rhizoctonia solani and Fusarium spp. In 60-day-old plants Trichoderma spp.. and B. japonicum inhibited the grouth of R. solani and Fusarium spp., whereas the use of B. japonicum (TAL-102 with T. harzianum. T. viride, T. koningii and T. pseudokoningii controlled the infection by M. phaseolina. Greater grain yield was recorded when B. japonium (TAI-102 was used with T. hamatum.
SHEN Qing-tao; CHEN Xiu-lan; SUN Cai-yun; ZHANG Yu-zhong
@@ The use of microorganisms for biological purposes has become an effective alternative to control plant pathogens. Trichoderma koningii Smf2 was chosen from eight Trichoderma strains for its thermostatic metabolites with antibiotic activity against Ralstonia solancearum Smith. Exclusion chromatography (LH20) was used twice to partially purify targeted metabolites combined with biological test. LC/ESI-MS, a powerful tool for rapid identification and sequence determination of peptides, identified these metabolites as three peptaibols named Trichokonin Ⅵ, Ⅶ and Ⅷ, and their sequences were confirmed with NMR.
Lehmann, Linda Olkjær; Petersen, Nanna; I. Jørgensen, Christian;
Trichoderma reesei expresses a large number of enzymes involved in lignocellulose hydrolysis and the mechanism of how these enzymes work together is too complex to study by traditional methods, e.g. by spiking with single enzymes and monitoring hydrolysis performance. In this study a multivariate...... approach, partial least squares regression, was used to see if it could help explain the correlation between enzyme profile and hydrolysis performance. Diverse enzyme mixtures were produced by Trichoderma reesei Rut-C30 by exploiting various fermentation conditions and used for hydrolysis of washed...
姚艳平; 李友莲; 王建明; 张作刚
木霉菌是重要的植物病害生防菌.通过对峙培养法,测定了哈茨木霉(Trichoderma harzianum)菌株NF9和绿木霉(Tric hode rmavire ns)菌株TY对3种土传植物病原真菌的体外拮抗作用.结果表明,这2株木霉菌对黄瓜枯萎病菌、西瓜枯萎病菌及茄子白绢病菌均具有一定的拮抗作用,不同木霉菌株间拮抗效果存在差异,哈茨木霉菌株NF9优于绿木霉菌株TY.%The fungous Trichoderma is an important microorganism in the biological control of plant diseases. The antagonism of Trichoderma harzianum NF9 and Trichoderma virens TY against three soil-borne plant fungous pathogens, Fusarium oxysporum Schl. f. sp. cucumerin Owen, Sclerotium rolfsii and Fusarium oxysporum Schl. f. sp. niveum, were tested in vitro by dual—culture. The result showed that two Trichoderma isolates had antagonism effect on the tested pathogens, and Trichoderma harzianum NF9 was better than Trichoderma virens TY in antagonism effect.
Shukla, Kruti; Hager, Heather A; Yurkonis, Kathryn A; Newman, Jonathan A
Initial studies of grass-endophyte mutualisms using Schedonorus arundinaceus cultivar Kentucky-31 infected with the vertically transmitted endophyte Epichloë coenophiala found strong, positive endophyte effects on host-grass invasion success. However, more recent work using different cultivars of S. arundinaceus has cast doubt on the ubiquity of this effect, at least as it pertains to S. arundinaceus-E. coenophiala. We investigated the generality of previous work on vertically transmitted Epichloë-associated grass invasiveness by studying a pair of very closely related species: S. pratensis and E. uncinata. Seven cultivars of S. pratensis and two cultivars of S. arundinaceus that were developed with high- or low-endophyte infection rate were broadcast seeded into 2 × 2-m plots in a tilled, old-field grassland community in a completely randomized block design. Schedonorus abundance, endophyte infection rate, and co-occurring vegetation were sampled 3, 4, 5, and 6 years after establishment, and the aboveground invertebrate community was sampled in S. pratensis plots 3 and 4 years after establishment. Endophyte infection did not enable the host grass to achieve high abundance in the plant community. Contrary to expectations, high-endophyte S. pratensis increased plant richness relative to low-endophyte cultivars. However, as expected, high-endophyte S. pratensis marginally decreased invertebrate taxon richness. Endophyte effects on vegetation and invertebrate community composition were inconsistent among cultivars and were weaker than temporal effects. The effect of the grass-Epichloë symbiosis on diversity is not generalizable, but rather specific to species, cultivar, infection, and potentially site. Examining grass-endophyte systems using multiple cultivars and species replicated among sites will be important to determine the range of conditions in which endophyte associations benefit host grass performance and have subsequent effects on co
Yougen Wu; Sisay Girmay; Vitor Martins da Silva; Brian Perry; Xinwen Hu; Tan, Ghee T.
We hypothesize that the fungal endophytes of noni may possibly play a role in its overall pharmacological repertoire, especially since the perceived efficacy of the fruit in ethnomedicinal use is associated with the fermented juice. The foremost goal of this study is to explore the role of endophyte-derived secondary metabolites in the purported anticancer properties of noni. To that end, culturable endophytic fungi resident within the healthy leaves and fruit of the plant were isolated and i...
Van Bael Sunshine A
Full Text Available Abstract Background Previous work has shown that leaf-cutting ants prefer to cut leaf material with relatively low fungal endophyte content. This preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in their host plants’ defense against leaf-cutting ants. To measure the long-term cost to the ant colony of fungal endophytes in their forage material, we conducted a 20-week laboratory experiment to measure fungal garden development for colonies that foraged on leaves with low or high endophyte content. Results Colony mass and the fungal garden dry mass did not differ significantly between the low and high endophyte feeding treatments. There was, however, a marginally significant trend toward greater mass of fungal garden per ant worker in the low relative to the high endophyte treatment. This trend was driven by differences in the fungal garden mass per worker from the earliest samples, when leaf-cutting ants had been foraging on low or high endophyte leaf material for only 2 weeks. At two weeks of foraging, the mean fungal garden mass per worker was 77% greater for colonies foraging on leaves with low relative to high endophyte loads. Conclusions Our data suggest that the cost of endophyte presence in ant forage material may be greatest to fungal colony development in its earliest stages, when there are few workers available to forage and to clean leaf material. This coincides with a period of high mortality for incipient colonies in the field. We discuss how the endophyte-leaf-cutter ant interaction may parallel constitutive defenses in plants, whereby endophytes reduce the rate of colony development when its risk of mortality is greatest.
Rogers, James K.; Ben C. Morton; Jagadeesh Mosali
Tall fescue (Lolium arundinaceum) infected with an endophyte (Neotyphodium spp.) generally has agronomic advantages over endophyte-free tall fescue. The objective of this study was to determine if endophyte presence (E+) or absence (E−) in three tall fescue genotypes affects concentrations of acid detergent fiber (ADF), neutral detergent fiber (NDF), nitrogen (N), and phosphorus (P) in field and greenhouse studies. E+ plants had higher concentrations of ADF and NDF (nonsignificant in one ge...
Shukla, Kruti; Hager, Heather A.; Yurkonis, Kathryn A.; Newman, Jonathan A.
Initial studies of grass–endophyte mutualisms using Schedonorus arundinaceus cultivar Kentucky-31 infected with the vertically transmitted endophyte Epichloë coenophiala found strong, positive endophyte effects on host-grass invasion success. However, more recent work using different cultivars of S. arundinaceus has cast doubt on the ubiquity of this effect, at least as it pertains to S. arundinaceus–E. coenophiala. We investigated the generality of previous work on vertically transmitted Epi...
Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Kithsiri Wijeratne; Leslie Gunatilaka; A Elizabeth Arnold
Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have ...
Devi Rachelia; Yogiara, Susan Soka; Stella Magdalena
Herbal plants have been believed by Indonesians to be an alternative medicine to treat illnesses. The bioactivecompounds in the plant can be derived from secondary metabolites or from endophytic and phyllosphere bacteria whichcoexist within medicinal plants. A total of 18 endophytic bacteria and 32 phyllosphere bacteria were isolated from theherbal plants of Citrus sp., Pluchea indica, Curcuma longa, Nothopanax scuttelarium, Piper crocatum, andAndrographis paniculata. About 72% of endophytic ...
JM Dalal; NS Kulkarni
Present investigation was carried out to study variation in endophytic fungal population colonizing soybean. Endophytic population was assessed at different growth stages of soybean (C.V. JS-335) viz., vegetative and reproductive stages. A 182 (28.88 %) isolates were obtained from vegetative growth stages (V1-V5) and 448 (71.11 %) from reproductive growth stages. As plant grows the endophytic population increases progressively however, at the onset of reproductive stages viz., R1-R8 the endop...
Full Text Available Trichoderma are ubiquitous soil fungi that include species widely used as biocontrol agents in agriculture. Many isolates are known to secrete several secondary metabolites with different biological activities towards plants and other microbes. Harzianic acid (HA is a T. harzianum metabolite able to promote plant growth and strongly bind iron. In this work, we isolated from the culture filtrate of a T. harzianum strain a new metabolite, named isoharzianic acid (iso-HA, a stereoisomer of HA. The structure and absolute configuration of this compound has been determined by spectroscopic methods, including UV-Vis, MS, 1D and 2D NMR analyses. In vitro applications of iso-HA inhibited the mycelium radial growth of Sclerotinia sclerotiorum and Rhizoctonia solani. Moreover, iso HA improved the germination of tomato seeds and induced disease resistance. HPLC-DAD experiments showed that the production of HA and iso HA was affected by the presence of plant tissue in the liquid medium. In particular, tomato tissue elicited the production of HA but negatively modulated the biosynthesis of its analogue iso-HA, suggesting that different forms of the same Trichoderma secondary metabolite have specific roles in the molecular mechanism regulating the Trichoderma plant interaction.
Randjelović Pavle; Veljković Slavimir; Stojiljković Nenad; Sokolović Dušan; Ilić Ivan; Laketić Darko; Randjelović Dušica; Randjelović Nebojša
Salicylic acid is a phytochemical with beneficial effects on human well-being. Salicylic acid is a phenolic compound and is present in various plants where it has a vital role in protection against pathogenic agents. Natural sources include fruits, vegetables and spices. The most famous and defined effect of salicylic acid is prostaglandin synthesis inhibition. Salicylic acid has antiinflammatory effects through suppression of transcription of genes for cyclooxygenase. Most of the pharmacolog...
Full Text Available Mangrove forests play an important role in subtropical and tropical coastal ecosystems. Endophytic fungi are widely distributed in various ecosystems and have great contribution to global biodiversity. In order to better understand the effects of mangrove species and tissue types on endophytic fungal community, we investigated cultivable endophytic fungi in leaves and twigs of four mangroves Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorrhiza, and Kandelia candel in Guangxi, China. The four tree species had similar overall colonisation rates of endophytic fungi (24–33%. The colonisation rates of endophytic fungi were higher in twigs (30–58% than in leaves (6–25% in the four plant species. A total of 36 endophytic fungal taxa were identified based on morphological characteristics and molecular data, including 35 Ascomycota and 1 Basidiomycota, dominated by Phomopsis, Phyllosticta, Xylaria, Leptosphaerulina, and Pestalotiopsis. The diversity of endophytic fungi was higher in twigs than in leaves in the four plant species. Some endophytic fungi showed host and tissue preference. The endophytic fungal community composition was different among four mangrove species and between leaf and twig tissues.
Hardoim, Pablo R; van Overbeek, Leonard S; Berg, Gabriele; Pirttilä, Anna Maria; Compant, Stéphane; Campisano, Andrea; Döring, Matthias; Sessitsch, Angela
All plants are inhabited internally by diverse microbial communities comprising bacterial, archaeal, fungal, and protistic taxa. These microorganisms showing endophytic lifestyles play crucial roles in plant development, growth, fitness, and diversification. The increasing awareness of and information on endophytes provide insight into the complexity of the plant microbiome. The nature of plant-endophyte interactions ranges from mutualism to pathogenicity. This depends on a set of abiotic and biotic factors, including the genotypes of plants and microbes, environmental conditions, and the dynamic network of interactions within the plant biome. In this review, we address the concept of endophytism, considering the latest insights into evolution, plant ecosystem functioning, and multipartite interactions.
Vincent, J B; Weiblen, G D; May, G
Processes shaping the distribution of foliar fungal endophyte species remain poorly understood. Despite increasing evidence that these cryptic fungal symbionts of plants mediate interactions with pathogens and herbivores, there remain basic questions regarding the extent to which dispersal limitation and host specificity might shape fungal endophyte community composition in rainforests. To assess the relative importance of spatial pattern and host specificity, we isolated fungi from a sample of mapped trees in lowland Papua New Guinea. Sequences of the internal transcribed spacer (ITS) region were obtained for 2079 fungal endophytes from three sites and clustered into molecular operational taxonomic units (MOTUs) at 95% similarity. Multivariate analyses suggest that host affinity plays a significant role in structuring endophyte community composition whereas there was no evidence of endophyte spatial pattern at the scale of tens to hundreds of metres. Differences in endophyte communities between sampled trees were weakly correlated with variation in foliar traits but not with tree species relatedness. The dominance of relatively few generalist endophytes and the presence of a large number of rare MOTUs was a consistent observation at three sites separated by hundreds of kilometres and regional turnover was low. Host specificity appears to play a relatively weak but more important role than dispersal limitation in shaping the distribution of fungal endophyte communities in New Guinea forests. Our results suggest that in the absence of strong ecological gradients and host turnover, beta diversity of endophyte communities could be low in large areas of contiguous forest.
Lingfei, Li; Anna, Yang; Zhiwei, Zhao
Arbuscular mycorrhizal and dark septate endophytic fungal colonization in a grassland in Kunming, southwest China, was investigated monthly over one year. All plant roots surveyed were co-colonized by arbuscular mycorrhizal and dark septate endophytic fungi in this grassland. Both arbuscular mycorrhizal and dark septate endophytic fungal colonization fluctuated significantly throughout the year, and their seasonal patterns were different in each plant species. The relationships between environmental (climatic and edaphic) factors and fungal colonization were also studied. Correlation analysis demonstrated that arbuscular mycorrhizal colonization was significantly correlative with environmental factors (rainfall, sunlight hours, soil P, etc.), but dark septate endophytic fungal colonization was only correlative with relative humidity and sunlight hours.
Li, Peiqin; Wu, Zhou; Liu, Tao; Wang, Yanan
This study investigated the biodiversity, phylogeny, and antifungal activity of endophytic fungi isolated from Zanthoxylum bungeanum. A total of 940 isolates obtained were grouped into 93 morphotypes, 43 species, and 23 genera, which were authenticated by molecular identification based on rDNA internal transcribed spacer (ITS) sequence analysis. A high diversity of endophytic fungi from Z. bungeanum are observed with high species richness S (43), Margalef index D' (6.1351), Shannon-Wiener index H' (3.2743), Simpson diversity index Ds (0.9476), PIE index (0.9486), and evenness Pielou index J (0.8705) but a low dominant index λ (0.0524). Significant tissue specificity of the endophytic fungi was observed in Z. bungeanum, and the highest species richness and diversity indexes were obtained in the stem. Phylogenetic analyses of the 93 endophytic isolates were carried out by the neighbor-joining (NJ) method to demonstrate their evolutionary processes. Antifungal activities of endophytic fungi were assayed and eight endophytic isolates showed strong and long-lasting inhibition against host pathogenic fungi Fusarium sambucinum and Pseudocercospora zanthoxyli. Here, for the first time, we systematically demonstrate the biodiversity, phylogeny, and antifungal activity of endophytic fungi associated with Z. bungeanum and reveal the value of sampling different tissues of a given plant to obtain the greatest endophyte species diversity, which might offer a framework for further investigation and utilization of endophytic fungi as aunique source of interesting and useful bioactive compounds.
Young, C A; Hume, D E; McCulley, R L
Tall fescue [Lolium arundinaceum (Schreb.) Darbysh. syn. Festuca arundinacea Schreb.] and perennial ryegrass (Lolium perenne L.) are important perennial forage grasses utilized throughout the moderate- to high-rainfall temperate zones of the world. These grasses have coevolved with symbiotic fungal endophytes (Epichloë/Neotyphodium spp.) that can impart bioactive properties and environmental stress tolerance to the grass compared with endophyte-free individuals. These endophytes have proven to be very important in pastoral agriculture in the United States, New Zealand, and Australia, where forage grasses are the principal feed for grazing ruminants. In this review, we describe the biology of these grass-endophyte associations and implications for the livestock industries that are dependent on these forages. Endophyte alkaloid production is put in context with endophyte diversity, and we illustrate how this has facilitated utilization of grasses infected with different endophyte strains that reduce livestock toxicity issues. Utilization of tall fescue and use of perennial ryegrass in the United States, New Zealand, and Australia are compared, and management strategies focused predominantly on the success of endophyte-infected perennial ryegrass in New Zealand and Australia are discussed. In addition, we consider the impact of grass-endophyte associations on the sustainability of pasture ecosystems and their likely response to future changes in climate.
Kaur, Tamanreet; Singh, Bahaderjeet; Kaur, Amarjeet; Kaur, Sanehdeep
Fungal endosymbionts in plants may influence interactions among plants, herbivores and their parasitoids through the production of secondary metabolites. We used a lepidopteran pest and its generalist parasitoid to test the effect of endophyte-infected plants on a third trophic level. Endophytic fungi, Aspergillus flavus and Aspergillus niger, isolated from Acacia arabica, were used to infect cauliflower plants. We found that the presence of the endophyte in the plants significantly extended the development period of Spodoptera litura (Fab.) larvae. Feeding of the host on endophyte-infected plants further adversely affected the development and performance of its parasitoid, Bracon hebetor (Say). A negative impact was also recorded for longevity and fecundity of endophyte-naive parasitoid females due to the parasitization of host larvae fed on endophyte-infected plants. The presence of endophytes in the diet of the host larvae significantly prolonged the development of the parasitoid. A strong detrimental effect was also recorded for larval survival and emergence of parasitoid adults. The longevity and parasitism rate of female wasps were reduced significantly due to the ingestion of endophyte-infected cauliflower plants by S. litura larvae. Overall, we found that both endophytic fungi had a negative impact on the parasitoid.
Full Text Available This study investigated the biodiversity, phylogeny, and antifungal activity of endophytic fungi isolated from Zanthoxylum bungeanum. A total of 940 isolates obtained were grouped into 93 morphotypes, 43 species, and 23 genera, which were authenticated by molecular identification based on rDNA internal transcribed spacer (ITS sequence analysis. A high diversity of endophytic fungi from Z. bungeanum are observed with high species richness S (43, Margalef index D′ (6.1351, Shannon–Wiener index H′ (3.2743, Simpson diversity index Ds (0.9476, PIE index (0.9486, and evenness Pielou index J (0.8705 but a low dominant index λ (0.0524. Significant tissue specificity of the endophytic fungi was observed in Z. bungeanum, and the highest species richness and diversity indexes were obtained in the stem. Phylogenetic analyses of the 93 endophytic isolates were carried out by the neighbor-joining (NJ method to demonstrate their evolutionary processes. Antifungal activities of endophytic fungi were assayed and eight endophytic isolates showed strong and long-lasting inhibition against host pathogenic fungi Fusarium sambucinum and Pseudocercospora zanthoxyli. Here, for the first time, we systematically demonstrate the biodiversity, phylogeny, and antifungal activity of endophytic fungi associated with Z. bungeanum and reveal the value of sampling different tissues of a given plant to obtain the greatest endophyte species diversity, which might offer a framework for further investigation and utilization of endophytic fungi as aunique source of interesting and useful bioactive compounds.
Rasmussen, Susanne; Parsons, Anthony J; Bassett, Shalome; Christensen, Michael J; Hume, David E; Johnson, Linda J; Johnson, Richard D; Simpson, Wayne R; Stacke, Christina; Voisey, Christine R; Xue, Hong; Newman, Jonathan A
The relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. Here, we infected two perennial ryegrass (Lolium perenne) cultivars (AberDove, Fennema) that differ in carbohydrate content with three strains of Neotyphodium lolii (AR1, AR37, common strain) that differ intrinsically in alkaloid profile. We grew endophyte-free and infected plants under high and low nitrogen (N) supply and used quantitative PCR (qPCR) to estimate endophyte concentrations in harvested leaf tissues. Endophyte concentration was reduced by 40% under high N supply, and by 50% in the higher sugar cultivar. These two effects were additive (together resulting in 75% reduction). Alkaloid production was also reduced under both increased N supply and high sugar cultivar, and for three of the four alkaloids quantified, concentrations were linearly related to endophyte concentration. The results stress the need for wider quantification of fungal endophytes in the grassland-foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes or increasing N inputs affect the role of endophytes in grassland ecosystems.
Lin, Lan; Ge, Hui Ming; Yan, Tong; Qin, Yan Hua; Tan, Ren Xiang
Each plant species in nature harbors endophytes, a community of microbes living within host plants without causing any disease symptom. However, the exploitation of endophyte-based phytoprotectants is hampered by the paucity of mechanistic understandings of endophyte-plant interaction. We here reported two endophytic Streptomyces isolates IFB-A02 and IFB-A03 recovered from a stress-tolerant dicotyledonous plant Artemisia annua L. After the determination of their non-pathogenicity at the genomic level and from the toxin (thaxtomin A, TXT) level, the endophytism of both isolates was supported by their successful colonization in planta. Of the two endophytes, IFB-A03 was further studied for the mechanism of endophyte-conferred phytoprotection owing to its plant growth promotion in model eudicot Arabidopsis thaliana. Using the endophyte-Arabidopsis co-cultivation system into which pathogenic Streptomyces scabies was introduced, we demonstrated that IFB-A03 pre-inoculation could activate the salicylic acid (SA)-mediated plant defense responses upon pathogen challenge. Moreover, IFB-A03 was shown to partially rescue the defense deficiency in eds5 (enhanced disease susceptibility 5) Arabidopsis mutants, putatively acting at the upstream of SA accumulation in the defense signaling pathway associated with the systemic acquired resistance (SAR). These data suggest that endophytic Streptomyces sp. IFB-A03 could be a promising candidate for biocontrol agents against S. scabies--a causative pathogen of common scab diseases prevailing in agronomic systems.
El-Shatoury, Sahar A; El-Kraly, Omnia A; Trujillo, Martha E; El-Kazzaz, Waleed M; El-Din, El-Sayeda Gamal; Dewedar, Ahmed
The diversity of culturable endophytic actinomycetes associated with wild Compositae plants is scantily explored. In this study, one hundred and thirty one endophytic actinobacteria were isolated from ten Compositae plant species collected from South Sinai in Egypt. Microscopic and chemotaxonomic investigation of the isolates indicated fourteen genera. Rare genera, such as Microtetraspora, and Intrasporangium, which have never been previously reported to be endophytic, were identified. Each plant species accommodated between three to eight genera of actinobacteria and unidentified strains were recovered from seven plant species. The generic diversity analysis of endophytic assemblages grouped the plant species into three main clusters, representing high, moderate and low endophytic diversity. The endophytes showed high functional diversity, based on forty four catabolic and plant growth promotion traits; providing some evidence that such traits could represent key criteria for successful residence of endophytes in the endosphere. Stress-tolerance traits were more predictive measure of functional diversity differences between the endophyte assemblages (Shannon's index, p = 0.01). The results indicate a potential prominent role of endophytes for their hosts and emphasize the potency of plant endosphere as a habitat for actinobacteria with promising future applications.
Full Text Available This study aimed to screen the endophytic fungal species of ethano-medicinal plant Bacopa monnieri (L. Pennell for their ability to produce antimicrobial substances against Bacillus subtilis, Pseudomonas aeroginosa, Salmonella typhimurium, Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Candida albicans. Endophytes were also screened for their ability to produce amylase, cellulase, protease and lipase to evaluate their ecological role within the host plant. Twenty-six endophytes were isolated and seventeen were identified. All the isolated endophytes exhibited amylolytic activity. Lipolytic, cellulolytic, proteolytic activity was shown by 98, 28 and 31% isolates, respectively. Similarly, all the endophytes (100% exhibited significant antimicrobial activity against K. pneumonia, while seventeen endophytes (89.5% were active against S. aureus. Fourteen endophytes (78.9% showed significant antimicrobial activity against B. subtilis and C. albicans. Eleven (57.8%, nine (50%, four (21% endophytes were active against S. typhimurium, E. coli and P. aeruginosa, respectively.
Nieto-Jacobo, Maria F; Steyaert, Johanna M; Salazar-Badillo, Fatima B; Nguyen, Dianne Vi; Rostás, Michael; Braithwaite, Mark; De Souza, Jorge T; Jimenez-Bremont, Juan F; Ohkura, Mana; Stewart, Alison; Mendoza-Mendoza, Artemio
Trichoderma species are soil-borne filamentous fungi widely utilized for their many plant health benefits, such as conferring improved growth, disease resistance and abiotic stress tolerance to their hosts. Many Trichoderma species are able to produce the auxin phytohormone indole-3-acetic acid (IAA), and its production has been suggested to promote root growth. Here we show that the production of IAA is strain dependent and diverse external stimuli are associated with its production. In in vitro assays, Arabidopsis primary root length was negatively affected by the interaction with some Trichoderma strains. In soil experiments, a continuum effect on plant growth was shown and this was also strain dependent. In plate assays, some strains of Trichoderma spp. inhibited the expression of the auxin reporter gene DR5 in Arabidopsis primary roots but not secondary roots. When Trichoderma spp. and A. thaliana were physically separated, enhancement of both shoot and root biomass, increased root production and chlorophyll content were observed, which strongly suggested that volatile production by the fungus influenced the parameters analyzed. Trichoderma strains T. virens Gv29.8, T. atroviride IMI206040, T. sp. "atroviride B" LU132, and T. asperellum LU1370 were demonstrated to promote plant growth through volatile production. However, contrasting differences were observed with LU1370 which had a negative effect on plant growth in soil but a positive effect in plate assays. Altogether our results suggest that the mechanisms and molecules involved in plant growth promotion by Trichoderma spp. are multivariable and are affected by the environmental conditions.
Brotman, Yariv; Landau, Udi; Cuadros-Inostroza, Álvaro; Tohge, Takayuki; Takayuki, Tohge; Fernie, Alisdair R; Chet, Ilan; Viterbo, Ada; Willmitzer, Lothar
Trichoderma spp. are versatile opportunistic plant symbionts which can colonize the apoplast of plant roots. Microarrays analysis of Arabidopsis thaliana roots inoculated with Trichoderma asperelloides T203, coupled with qPCR analysis of 137 stress responsive genes and transcription factors, revealed wide gene transcript reprogramming, proceeded by a transient repression of the plant immune responses supposedly to allow root colonization. Enhancement in the expression of WRKY18 and WRKY40, which stimulate JA-signaling via suppression of JAZ repressors and negatively regulate the expression of the defense genes FMO1, PAD3 and CYP71A13, was detected in Arabidopsis roots upon Trichoderma colonization. Reduced root colonization was observed in the wrky18/wrky40 double mutant line, while partial phenotypic complementation was achieved by over-expressing WRKY40 in the wrky18 wrky40 background. On the other hand increased colonization rate was found in roots of the FMO1 knockout mutant. Trichoderma spp. stimulate plant growth and resistance to a wide range of adverse environmental conditions. Arabidopsis and cucumber (Cucumis sativus L.) plants treated with Trichoderma prior to salt stress imposition show significantly improved seed germination. In addition, Trichoderma treatment affects the expression of several genes related to osmo-protection and general oxidative stress in roots of both plants. The MDAR gene coding for monodehydroascorbate reductase is significantly up-regulated and, accordingly, the pool of reduced ascorbic acid was found to be increased in Trichoderma treated plants. 1-Aminocyclopropane-1-carboxylate (ACC)-deaminase silenced Trichoderma mutants were less effective in providing tolerance to salt stress, suggesting that Trichoderma, similarly to ACC deaminase producing bacteria, can ameliorate plant growth under conditions of abiotic stress, by lowering ameliorating increases in ethylene levels as well as promoting an elevated antioxidative capacity.
Krisztina Kovacs; George Szakacs; Lew Christopher
@@ The importance of microbial enzymes in pulp and paper manufacturing has grown significantly in the last two decades. Solid substrate fermentation (SSF) holds tremendous potential for the production of microbial enzymes of commercial interest. SSF can be of special interest in those processes where the crude fermented product (whole SSF culture, in situ enzyme) may be used directly as the enzyme source. Xylanase preparations practically free of cellulase activity are especially useful for biobleaching of crude cellulose pulps. Thirty-nine Trichoderma isolates have been screened in SSF for xylanase production on hardwood oxygen-delignified soda-aq pulp as carbon source and enzyme inducer.Xylanase activities varied between 0 and 2200 IU/g dry matter (DM) of initial substrate. In most instances, the simultaneously produced cellulase levels were below 1.0 Filter Paper Unit (FPU) /g DM. The xylanase to cellulase activity ratio varied in the range of 5 to 3500. The three most promising isolates (TUB F-1647, TUB F-1658 and TUB F-1684) yielded xylanase activity of 2040,1300 and 1500 IU/g DM xylanase, respectively, and 0.64, 0.43 and 0.43 FPU/g DM cellulase with a xylanase to cellulase activity ratio of 3200, 3000 and 3500, respectively. Wild strains F-1647, F-1658 and F-1684 were isolated from tree bark of Maldives, soils of Peru (last two), respectively.Medium optimization experiments to enhance the xylanase yield and to increase the xylanase to cellulase ratio have also been performed.
Full Text Available Screening and obtaining a novel high activity cellulase and its producing microbe strain is the most important and essential way to improve the utilization of crop straw. In this paper, we devoted our efforts to isolating a novel microbe strain which could produce high activity cellulase. A novel strain Trichoderma virens ZY-01 was isolated from a cropland where straw is rich and decomposed, by using the soil dilution plate method with cellulose and Congo red. The strain has been licensed with a patent numbered ZL 201210295819.6. The cellulase activity in the cultivation broth could reach up to 7.4 IU/mL at a non-optimized fermentation condition with the newly isolated T. virens ZY-01. The cellulase was separated and purified from the T. virens culture broth through (NH42SO4 fractional precipitation, anion-exchange chromatography and gel filtration chromatography. With the separation process, the CMC specific activity increased from 0.88 IU/mg to 31.5 IU/mg with 35.8 purification fold and 47.04% yield. Furthermore, the enzymatic properties of the cellulase were investigated. The optimum temperature and pH is 50 °C and pH 5.0 and it has good thermal stability. Zn2+, Ca2+ and Mn2+ could remarkably promote the enzyme activity. Conversely, Cu2+ and Co2+ could inhibit the enzymatic activity. This work provides a new highly efficient T. virens strain for cellulase production and shows good prospects in practical application.
Fungal endophytes may contribute to plant health and disease protection, yet little is known about their various roles in alfalfa. Also, endophytes from several plant species produce novel antimicrobial compounds that may be useful clinically. We isolated endophytic fungi from over 50 samples from s...
Ergot alkaloids in endophyte-infected grasses inhibit prolactin (PRL) secretion and may reduce milk production of cows consuming endophyte-infected grasses. We investigated the effects of consuming endophyte-infected fescue during late lactation and the dry period on mammary growth, differentiation ...
Zhou, Yanfei; Bradshaw, Rosie E; Johnson, Richard D; Hume, David E; Simpson, Wayne R; Schmid, Jan
Perennial ryegrass (Lolium perenne) is a widely used pasture grass, which is frequently infected by Neotyphodium lolii endophytes that enhance grass performance but can produce alkaloids inducing toxicosis in livestock. Several selected endophyte strains with reduced livestock toxicity, but that confer insect resistance, are now in common use. Little is known regarding the survival and persistence of these endophytes when in competition with common toxic endophytes. This is mainly because there are currently no assays available to easily and reliably quantify different endophytes in pastures or in batches of seeds infected with multiple strains. We developed real time PCR assays, based on secondary metabolite genes known to differ between N. lolii endophyte strains, to quantify two selected endophytes, AR1 and AR37, and a common toxic ecotype used in New Zealand. A duplex PCR allowed assessment of endophyte:grass DNA ratios with high sensitivity, specificity and precision. Endophyte specific primers/probes could detect contamination of AR37 seeds with other endophytes down to a level of 3-25%. We demonstrated that it is possible to quantify different endophyte strains simultaneously using multiplex PCR. This method has potential applications in management of endophytes in pastures and in fundamental research into this important plant-microbe symbiosis.
Francesco Vinale; Gaetano D' Ambrosio; Khalid Abadi; Felice Scala; Roberta Marra; David Turrà; Sheridan L Woo; Matteo Lorito
@@ Trichoderma strains are used in agriculture because they provide to the plants the following benefits:i) are rhizosphere competence and establish stable rhizosphere microbial communities; ii) control plant disease caused by pathogenic and competitive microflora, by using a variety of mechanisms; iii)improve vegetative growth, root development and yield; iv) make nutrients more available to the plant. In this work we have investigated the ability of T. harzianum T22 and T. atroviride P1 to improve plant growth of locally important horticultural crops: lettuce, tomatoes and peppers and to prevent disease in the greenhouse and field. The effect of the Trichoderma treatment was evaluated by determining the weight of fresh and dry roots and above ground plant biomass, measuring plants height, counting the number of emerged leaves (lettuce, tomatoes and peppers) and quantifying production (tomatoes and peppers). No disease symptoms were found during production, although Fusarium sp. strains pathogenic to tomato were detected in the soil. Compounds containing copper oxychloride are frequently used for fungal disease control in agriculture. In order to investigate the compatibility of T. harzianum T22 and T. atroviride P1 with copper oxychloride applications, the effect on mycelia growth was monitored in both liquid and solid medium. In general, the tests indicated a high level of tolerance of the Trichoderma strains to concentrations of copper oxychloride varying from 0.1 to 5 mmol/L.
Saito, Katsuharu; Kuga-Uetake, Yukari; Saito, Masanori; Peterson, R Larry
Phialocephala fortinii is a dark septate fungal endophyte that colonizes roots of many host species. Its effect on plant growth varies from being pathogenic to beneficial. The basic biology of this species has received little research, and thus the main objectives of this study were to determine cytological features of hyphae, including the nature of the vacuolar system, and whether polyphosphate was present in vacuoles. Both living hyphae and hyphae that had been rapidly frozen and freeze substituted before embedding were studied. A complex system of vacuoles, including a motile tubular vacuolar system, elongated vacuoles, and spherical vacuoles, was demonstrated in living hyphae by the fluorescent probe Oregon Green 488 carboxylic acid diacetate, using laser scanning confocal microscopy. The motile tubular vacuolar system was more prevalent at the hyphal tip than in more distal regions, whereas elongated vacuoles and spherical vacuoles were more abundant distal to the tip. All vacuoles contained polyphosphate as shown by labelling embedded samples with recombinant polyphosphate binding domain of Escherichia coli exopolyphosphatase, containing Xpress tag at the N-terminal end, followed by anti-Xpress antibody and a secondary antibody conjugated either to a fluorescent probe for laser scanning confocal microscopy or colloidal gold for transmission electron microscopy. The polyphosphate was dispersed in vacuoles. This was confirmed by staining embedded samples with 4',6-diamidino-2-phenylindole and viewing with UV light using epifluorescence microscopy. These cytological methods showed that the tubular vacuolar system had lower concentrations of polyphosphate than the spherical vacuoles. Lipid bodies were present around vacuoles.
Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki
Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418
Kubicek, Christian P.; Herrera-Estrella, Alfredo; Seidl, Verena; Crom, St& #233; phane Le; Martinez, Diego A.; Druzhinina, Irina S.; Zeilinger, Susanne; Casas-Flores, Sergio; Horwitz, Benjamin A.; Mukherjee, Prasun K.; Mukherjee, Mala; Kredics, L& #225; szlo; Alcaraz, Luis David; Aerts, Andrea; Antal, Zsuzsanna; Atanasova, Lea; Cervantes-Badillo, Mayte Guadalupe; Challacombe, Jean; Chertkov, Olga; McCluskey, Kevin; Coulpier, Fanny; Deshpande, Nandan; D& #246; hren, Hans von; Ebbole, Daniel J.; Esquivel-Naranjo, Edgardo Ulises; Fekete, Erzs& #233; bet; Flipphi, Michel; Glaser, Fabian; Gomez-Rodriguez, Elida Yazmin; Gruber, Sabine; Han, Cliff; Henrissat, Bernard; Hermosa, Rosa; Hern& #225; ndez-O?ate, Miguel; Karaffa, Levente; Kosti, Idit; Lindquist, Erika; Lucas, Susan; L& #252; beck, Mette; L& #252; beck, Peter Stephensen; Margeot, Antoine; Metz, Benjamin; Misra, Monica; Nevalainen, Helena; Omann, Markus; Packer, Nicolle; Perrone, Giancarlo; Uresti-Rivera, Edith Elena; Salamov, Asaf; Schmoll, Monika; Seiboth, Bernhard; Shapiro, Harris; Sukno, Serenella; Tamayo-Ramos, Juan Antonio; Thon, Michael; Tisch, Doris; Wiest, Aric; Wilkinson, Heather H.; Zhang, Michael; Coutinho, Pedro M.; Kenerley, Charles M.; Monte, Enrique; Baker, Scott E.; Grigoriev, Igor V.
Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma.
Trichoderma conidia are mostly produced by solid fermentation systems. Inoculum is produced by liquid culturing, and then transferred to solid substrate for aerial conidial production. Aerial conidia of T. harzianum are hydrophilic in nature, and it is difficult to separate them from the solid subst...
Otieno, W.; Termorshuizen, A.J.; Jeger, M.J.
Soil solarization was evaluated singly or in combination with Trichoderma harzianum infestation or coffee pulp amendment for its effect on wood-borne inoculum of an Armillaria sp. pathogenic on tea. Solarization increased maximum soil temperatures at 10 cm depth by 9-12degreesC and reduced viability
Bech, Lasse; Herbst, Florian-Alexander; Grell, Morten Nedergaard
The on-site production of cell wall degrading enzymes is an important strategy for the development of sustainable bio-refinery processes. This study concerns the optimization of production of plant cell wall-degrading enzymes produced by Trichoderma asperellum. A comparative secretome analysis...
Full Text Available Trichoderma species are present in many ecosystems and some strains have the ability to reduce the severity of plant diseases by activating various defence pathways via specific biologically active signaling molecules. Hence we investigated the effects of low molecular weight volatile compounds of Trichoderma asperellum IsmT5 on Arabidopsis thaliana. During co-cultivation of T. asperellum IsmT5 without physical contact to A. thaliana we observed smaller but vital and robust plants. The exposed plants exhibit increased trichome numbers, accumulation of defence-related compounds such as H2O2, anthocyanin, camalexin, and increased expression of defence related genes. We conclude that A. thaliana perceives the Trichoderma volatiles as stress compounds and subsequently initiates multilayered adaptations including activation of signaling cascades to withstand this environmental influence.The prominent headspace volatile of T. asperellum IsmT5 was identified to be 6-pentyl-α-pyrone, which was solely applied to A. thaliana to verify the growth and defence reactions. Most noticeable is that A. thaliana preexposed to 6PP showed significantly reduced symptoms when challenged with Botrytis cinerea and Alternaria brassicicola, indicating that defence-activated plants subsequently became more resistant to pathogen attack. Together, these results support that products that are based on Trichoderma volatiles have the potential being a useful biocontrol agent in agriculture.
... margin of safety does not apply. VII. Other Considerations A. Endocrine Disruptors The Agency has no information to suggest that Trichoderma asperellum strain ICC 012 has an effect on the endocrine system. No... reports of the organism affecting endocrine systems. Therefore, it is unlikely that this organism...
... Considerations A. Endocrine Disruptors The Agency has no information to suggest that Trichoderma gamsii strain ICC 080 has an effect on the endocrine system. The submitted acute pulmonary toxicity/pathogenicity... organism in the environment and there have been no reports of the organism affecting endocrine...
Lehmann, Linda Olkjær; Petersen, Nanna; I. Jørgensen, Christian;
Trichoderma reesei expresses a large number of enzymes involved in lignocellulose hydrolysis and the mechanism of how these enzymes work together is too complex to study by traditional methods, e.g. by spiking with single enzymes and monitoring hydrolysis performance. In this study a multivariate...
This investigation aimed to assess whether MALDI-TOF MS analysis of proteomics could be applied to the study of Trichoderma, a fungal genus selected because it includes many species and is phylogenetically well defined. We also investigated whether MALDI-TOF MS analysis of proteomics would reveal ap...
M. Taghinasab Darzi
Full Text Available This experiment was performed to investigate the effect of some Trichoderma spp. isolates as growth promoters of cucumber (Cucumis sativus L. seedlings under greenhouse conditions. Inoculai of 19 Thrichoderma spp. isolates were prepared from disinfected wheat grain. The upper half of the soil in pots (containing field soil and sand was mixed with these inoculai at 3% ratio and the pots were irrigated with tap water for 28 days. After four weeks, the seedlings were sampled for growth comparison on stem length, root length and total fresh weight. The results showed that some isolates improved significantly the cucumber seedlings’ growth and others had inhibitory effect. Application of Trichoderma spp. 17 and T. longibraciatum increased stem length more than 74% as compared to control. Also, these isolates increased significantly P<0.05 the total fresh weight about 40% and 25%, respectively, as compared to control. Furthermore, Trichoderma sp. 19 decreased significantly the stem length, root length and total fresh weight as compared to control. These results show the ability of Persian Trichoderma spp. isolates in promoting cucumber growth and its potential for other plants.
E.V. Nguyen; S.Y. Imanishi; P. Haapaniemi; A. Yadav; M. Saloheimo; G.L. Corthals; T.M. Pakula
The filamentous fungus Trichoderma reesei is used for industrial production of secreted enzymes including carbohydrate active enzymes, such as cellulases and hemicellulases. The production of many of these enzymes by T. reesei is influenced by the carbon source it grows on, where the regulation syst
Smirnova, I P; Shneider, Yu A; Karimova, E V
A method for PCR diagnosis of impatiens necrotic spot virus is developed. Concentrated culture fluid with active L-lysine-α-oxidase (0.54 U/ml) from Trichoderma harzianum Rifai fungus producer strain F-180 inhibits vitally hazardous impatiens necrotic spot phytovirus.
The biocontrol agent, Trichoderma virens, has the ability to protect plants from pathogens by eliciting plant defense responses, involvement in mycoparasitism, or secreting antagonistic secondary metabolites. SM1, an elicitor of induced systemic resistance (ISR), was found to have three paralogs wi...