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Abstract
Nematophagous basidiomycete fungi kill nematodes by trapping, endoparasitizing and producing toxin. In our studies Coprinus comatus (O.F.Müll. : Fr.) Pers. is found to be a nematode-destroying fungus; this fungus immobilizes, kills and uses free-living nematode Panagrellus redivivus Goodey and root-knot nematode Meloidogyne arenaria Neal. C. comatus produces an unusual structure designated spiny ball. Set on a sporophore-like branch, the spiny ball is a burr-like structure assembled with a large number of tiny tubes. Purified spiny balls exhibit moderate nematicidal activity. Experiments show that spiny balls are not chlamydospores because of the absence of nuclei in the structures and quick formation within 3 d in a young colony. Nematodes added to C. comatus cultures on potato-dextrose agar (PDA) and cornmeal agar (CMA) become inactive in hours. Infection of nematodes by the fungus occurs only after the nematodes are immobilized (feeble or dead), probably by a toxin. Electron micrographs illustrate that C. comatus infect P. redivivus by producing penetration pegs with which hyphae colonize nematode bodies. An infected nematode is digested and consumed within days and hyphae grow out of the nematode.
... (Sufiate et al., 2017). Coprinus comatus preys on Panagrellus redivivus and Meloidogyne arenaria, nematodes that attack plants (Luo et al., 2004). This macrofungus has toxic, spiny ball structures at the end of the hyphal branches that pierce the body of the prey, killing it in minutes (Luo et al., 2004). ...
... Coprinus comatus preys on Panagrellus redivivus and Meloidogyne arenaria, nematodes that attack plants (Luo et al., 2004). This macrofungus has toxic, spiny ball structures at the end of the hyphal branches that pierce the body of the prey, killing it in minutes (Luo et al., 2004). Colonizing hyphae then penetrate the prey's body through the wounds to digest and assimilate its contents (Mora et al., 2018). ...
Niego A.G.T., Rapior S., Thongklang N., Raspé O., Hyde K.D., Mortimer P.
Reviewing the contributions of macrofungi to forest ecosystem processes and services.
Fungal Biology Reviews, 44, June, 100294 (2023). doi:10.1016/j.fbr.2022.11.002. hal-03891167 ____
Macrofungi are vital components of any forest ecosystem, performing different roles
crucial to ecosystem functioning. Macrofungi play effective roles in ecosystem processes
such as nutrient cycling. Ectomycorrhizal fungi and plant symbionts work together to
accumulate, use and transfer essential nutrients, especially in nitrogen/phosphoruslimited environments. Pathogenic and predatory macrofungi exploit other resources
such as plants and animals to obtain nutrients needed for growth. These groups of macrofungi also contribute to the species diversity of forest ecosystems. Saprotrophic macrofungi degrade available organic matter from dead plants and soil organic matter.
Macrofungi also play an important role in carbon sequestration in the forest underground
as well as in soil formation. Macrofungi remediate pollutants in the environment via extracellular enzymes. Mycelial networks that connect macrofungi to their symbiotic hosts and
substrates enable most of these functions. Mycelial networks facilitate the absorption and
transport of nutrients as well as the secretion of enzymes and other organic substances.
Spore-producing bodies of macrofungi serve as a food source for wildlife. Fungal spores
can act as aerosols in rain formation. All of these functions of macrofungi are necessary
for maintaining biodiversity and healthy forest ecosystems. However, the contributions
of macrofungi to ecosystem processes are often taken for granted or not fully recognized,
offering key services that are easily overlooked in planning processes and policymaking
The present review summarizes the major roles of macrofungi in ecosystem functioning and services rendered, and the interrelationships between these functions and services in the forest ecosystems.
... Incubation was performed at 25°C in the dark for 10 days. Under aseptic conditions, with the aid of a spatula, the aerial mycelium was scraped from discs (Luo et al., 2004(Luo et al., , 2007 with WA and PDA50. After the removal of aerial hyphae, Petri dishes were incubated at 25°C for a period of 20-28 h. ...
... The use of the mushroom substrate as a measure to control nematodes is an alternative for the discard of mushroom substrate. This material colonized by the mushroom mycelium, which for some species may present nematode predation structures (Barron and Thorn, 1987;Luo et al., 2007Luo et al., , 2006Luo et al., , 2004Thorn and Barron, 1984;Truong et al., 2007;Zouhar et al., 2013) and toxins (Kwok et al., 1992;Li et al., 2007), can kill not only nematodes, but also inhibit other phytopathogenic microorganisms. Several works have reported at least some inhibitory effect of mushrooms and their products against some pathogens such as Colletotrichum orbiculare (Parada et al., 2012), Phytophthora capsici (Chen et al., 2012;Kang et al., 2017), Ralstonia solanacearum (Kwak et al., 2015;Silva et al., 2007). ...
... ???????????? ?? ??????? C. comatus ????????????? ??????????? ??????????? ? ??????, ??????????? ????????????? ???????????. ????????? ????????????? ????????, ??? ?????? ??? ????????? ????? ???? ?????????????? ?? ?????? ??????? ( Luo et al., 2004). ??????????? ???? ?????? ?????????? ??? ???????? ????? ??? ?spiny ball?. ?????? ????? ???????? ???????????? ? ...
... ?????? ?????????? ???? ? ??????? ??????????? ?????? ????????, ???????? ??????????? ????? ??????????? ( Luo et al., 2004Luo et al., , 2007. ? ...
В монографии представлены основные вопросы и проблемы науки о лекарственных грибах,
результаты многолетних исследований биологических, нейротропных, медико‐фармакологических, аккумулирующих свойств и культуральных особенностей макромицетов.
Издание предназначено для микологов, медиков, экологов, специалистов в области
грибоводства и охраны окружающей среды, преподавателей и студентов ВУЗов.
У монографії представлені основні питання та проблеми науки про лікарські гриби,
результати багаторічних досліджень біологічних, нейротропних, медико‐фармакологічних,
акумулюючих властивостей та культуральних особливостей макроміцетів. Видання
призначене для мікологів, медиків, екологів, спеціалістів у грибівництві і охороні довкілля,
викладачів та студентів ВНЗів.
This monograph displays the questions and problems of medicinal mushroom science. These are results
of long‐term studies of biological, neurotropic, medicinal, pharmaceutical, accumulating, and cultural
properties of macromycetes. This edition will be of value to mycologists, physicians, ecologists, and
specialists in the field of mushroom cultivation and environmental protection, teachers, and students of
high school.
... At the final stage of the penetration process, the attacking fungus forms an infection bulb in the penetration tube [103]. This bulb produces new trophic hyphae that colonize and digest the nematode [104]. The dense bodies gradually degrade as the infected ball and vegetative mycelium mature, but normal fungal organelles are activated, and the endoplasmic reticulum is remarkably developed [61]. ...
Parasitic nematodes cause great annual loss in the agricultural industry globally. Arthrobotrys oligospora is the most prevalent and common nematode-trapping fungus (NTF) in the environment and the candidate for the control of plant- and animal-parasitic nematodes. A. oligospora is also the first recognized and intensively studied NTF species. This review highlights the recent research advances of A. oligospora as a model to study the biological signals of the switch from saprophytism to predation and their sophisticated mechanisms for interacting with their invertebrate hosts, which is of vital importance for improving the engineering of this species as an effective biocontrol fungus. The application of A. oligospora in industry and agriculture, especially as biological control agents for sustainable purposes, was summarized, and we discussed the increasing role of A. oligospora in studying its sexual morph and genetic transformation in complementing biological control research.
... Some saprophytic fungi, such as basidiomycetes, can only survive on substrates with high C/N ratios and, therefore, depend on nitrogen supplementation. These fungi, to meet their nitrogen needs, developed nematode predation strategies [33,69]. Thus, the higher demand for nitrogen in the growth medium might have compromised nitrogen absorption by plants, but remaining fungal populations might have been favored. ...
Background
The interest in the development of products that cause less damage to the environment associated with the loss of efficiency of chemical nematicides for the control management of nematodes is growing. Thus, the adoption of biological control or the use of biopesticides are excellent options for these products like those based on chemical compounds, such as commercial pesticides and anthelmintic (AH) drugs. Spent mushroom substrate (SMS), a product of the mushroom production industry, has great potential for biological control due to its high levels of mycelium, residual enzymes, high humidity and unique microbiota that may contain other nematode antagonists. For this reason, this study aimed to evaluate the potential of spent mushroom substrate (SMS) from Pleurotus djamor cultivation in the control of Meloidogyne javanica in lettuce and assess its effects on plant resistance enzymes and soil biological activity.
Results
SMS reduced by 98.68% the nematode reproduction, and a plateau was reached at SMS concentrations above 15%. For the population density of nematode (nematode g-1 root), this reduction was 99,75%. Higher concentrations of SMS caused phytotoxicity in lettuce, with reduction of vegetative variables, chlorophyll content and nitrogen balance in the leaves; however, SMS increased the anthocyanin content. Guaiacol peroxidase activity was the highest in treatments containing 0% and 30% SMS and phenylalanine ammonia-lyase activity was the highest in the 60% SMS treatment, suggesting induction of resistance to M. javanica. The maximum soil basal respiration was estimated to be achieved with 25.75% SMS, whereas the maximum soil metabolic quotient was estimated to be achieved with 8.8% SMS. Soil biomass carbon increased with increasing SMS proportion.
Conclusions
Spent substrate from P. djamor cultivation incorporated in soil at proportions of 15, 30, 45 and 60% is efficient in controlling M. javanica in lettuce.
Graphical Abstract
... Some saprophytic fungi, such as basidiomycetes, can only survive on substrates with high C/N ratios and, therefore, depend on nitrogen supplementation. These fungi, to meet their nitrogen needs, developed nematode predation strategies (Luo et al. 2004; Thorn and Barron 1984). Thus, the higher demand for nitrogen in the growth medium might have compromised nitrogen absorption by plants, but remaining fungal populations might have been favored. ...
Background
The interest in the development of ecologically correct products associated with the loss of efficiency of chemical nematicides for the control management of this pest is growing. Thus, the adoption of biological control or the use of biopesticides are excellent options for these products. Spent mushroom substrate (SMS), a product of the mushroom production industry, has great potential for biological control due to its high levels of mycelium, residual enzymes, high humidity and unique microbiota that may contain other nematode antagonists. For this reason, this study aimed to evaluate the potential of spent mushroom substrate (SMS) from Pleurotus djamor cultivation in the control of Meloidogyne javanica in lettuce and assess its effects on plant resistance enzymes and soil biological activity.
Results
SMS reduced nematode reproduction, and a plateau was reached at SMS concentrations above 15%. Higher concentrations of SMS caused phytotoxicity in lettuce, with reduction of vegetative variables, chlorophyll content and nitrogen balance in the leaves; however, SMS increases the anthocyanin content. Guaiacol peroxidase activity was highest in treatments containing 0% and 30% SMS and phenylalanine ammonia-lyase activity was highest in the 60% SMS treatment, suggesting induction of resistance to M. javanica. The maximum soil basal respiration was estimated to be achieved with 25.75% SMS, whereas the maximum soil metabolic quotient was estimated to be achieved with 8.8% SMS. Soil biomass carbon increased with increasing SMS proportion.
Conclusions
Spent substrate from P. djamor cultivation incorporated in soil at proportions of 15, 30, 45 e 60% is efficient in controlling M. javanica in lettuce.
... Li et al. (2010) cita propiedades antioxidantes del extracto alcohólico y acuoso del pie y píleo. Otra propiedad interesante es la de actuar como insecticida de nematodos (Luo et al., 2004). ...
Se cita a Coprinus comatus como nuevo registro para el Paraguay. Las características morfológicas distintivas de la especie son la forma del basidioma, láminas delicuescentes, las escamas pronunciadas del píleo y las esporas oscuras con poro germinativo. Se proporcionan datos sobre las características morfológicas de la especie, su distribución, ecología y una discusión en torno a su taxonomía. Además se ilustran los caracteres microscópicos distintivos. Se anexan fotografías del basidioma en fresco y de las estructuras microscópicas como basidios y basidiosporas.
... The notable nematophagous fungi are nematode-trapping fungi from Orbilliaceae [13]. Variation in trapping devices of nematode-trapping fungi may differ in each species namely adhesive network, adhesive knobs, constricting rings, non-constricting rings, adhesive branches, undifferentiated/ unmodified adhesive hyphae, stephanocysts, spiny balls and acanthocytes [14,15]. Colonization of nematodes by nematophagous fungi were initially begun with immobilization using dense mycelial mats. ...
Root-knot nematodes are important agricultural pests causing serious economical loss to harvestable crops. Biological control using nematophagous fungi is one option to mitigate these infection through mechanism of physical or chemical killing methods. The present study tried to explore a possibility of finding native nematophagous fungal strains in the hope on discovery of novel and potential isolates originating from freshwater region of Toba Lake, North Sumatra, Indonesia. Isolation of nematophagous fungi was based on sprinkle and pour combination method on Chloramphenicol-Water Agar (CWA) incubated for 30 days. Freshwater samples of soil and sediments were collected from 28 sampling sites characterized by different anthropogenic activities as natural, fishery, residential, plantation and tourism area. Daily examination is conducted to obtain a single culture of nematophagous fungi sub-cultured on Potato Dextrose Agar (PDA) medium. Eleven isolates were observed to initiate predatory activities against tested Caenorhabditis elegans based on qualitative screening. The isolates showed either mechanical killing or chemical killing of nematodes during co-inoculation with nematodes. Micromorphological and molecular analysis are currently being conducted to obtain species identity from each isolate.
... Traps of adhesive hyphae are restricted to the genera Stylopage and Cystopage of Zygomycetes (58), while stephanocysts are restricted to the genus Hyphoderma of Basidiomycota (51). Spiny balls and acanthocytes are only formed, respectively, by Coprinus comatus (53,54) and Stropharia rugosoannulata (59) in Agaricales of Basidiomycota. The sexual morphs of most nematodetrapping species are now assigned to Orbilia, and their type of trapping apparatus can be used as robust indicators of generic delimitation. ...
... Li et al. (2010) cita propiedades antioxidantes del extracto alcohólico y acuoso del pie y píleo. Otra propiedad interesante es la de actuar como insecticida de nematodos (Luo et al., 2004). Hábitat: Nitrófilo, saprófito, solitario o en pequeños grupos. ...
Evaluación del crecimiento de macrohongos de interés biotecnológico en residuos agroindustriales y madederos. Se evaluó la capacidad de crecimiento de cepas de macrohongos nativos del Paraguay de interés biotecnológico: Trametes versicolor, Pleurotus ostreatus y Schizophyllum commune en medios de cultivo enriquecidos con residuos agroindustriales y madereros. Se prepararon medios con las siguientes combinaciones: Pino/Paja, Pino/Caña, Lapacho/Paja, Lapacho/Caña. Para las cepas T. versicolor y P. ostreatus, el medio de cultivo óptimo de crecimiento fue el enriquecido con la combinación Pino/Paja, la cepa S. commune mostró similar crecimiento en los diferentes medios utilizados. Los medios enriquecidos con lapacho presentaron efecto inhibitorio sobre las cepas T. versicolor y P. ostreatus, probablemente debido al compuesto naftoquinónico (lapachol) con propiedades antifúngicas reportadas en la literatura. La cepa S. commune creció favorablemente en medios enriquecidos con lapacho, lo que sugiere que esta cepa posee complejos multienzimáticos capaces de bloquear el efecto inhibitorio del lapachol. El presente trabajo experimental es el primer antecedente relacionado con cepas de Macrohongos del Paraguay. Palabras Claves: biotecnología, degradadores de madera, hongos, residuos Growth assessment of macrogungi with biotechnological interest in agro-industrial and timber waste. The growth capacity of native fungal strains from Paraguay and of biotechnological interest: Trametes versicolor, Pleurotus ostreatus and Schizophyllum commune were evaluated in various culture media enriched with agroindustrial waste (Straw and Bagasse) and wood (sawdust Pine and Lapacho). Culture media were prepared with the following combinations: Pine/Straw, Pine/Reed, Lapacho/Straw, Lapacho/Reed. For both T. versicolor and P. ostreatus strains, the optimum growth culture medium was enriched with Pine/Straw combination, but the strain S. commune showed similar growth in all the different culture media used.Media enriched with Lapacho had inhibitory effect on T. versicolor and P. ostreatus strains, probably due to naphthoquinone compound (lapachol) with antifungal properties reported in the literature. S. commune strain grew favorably in Lapacho enriched culture media, suggesting that this strain has multienzyme complexes capable of blocking the inhibitory effect of lapachol. This experimental work is the first Macrofungi antecedent related with strains of Paraguay.
... These adaptations are very similar to those found in entomopathogenic and mycoparasitic fungi, and interconversion between these different lifestyles seems to have been common in the Hypocreales (Pezizomycotina) ). Many nematophagous fungi are known to associate with plants as endophytes or wood decomposers (Luo et al., 2004;Larriba et al., 2014;Wani et al., 2015;de Mattos-Shipley et al., 2016) (Fig. 4). Again, the endophytic lifestyle is very common among nematophagous, entomopathogenic and mycoparasitic Hypocreales, and these capabilities might have evolved as part of a symbiotic relationship in which the fungus protects the plant against parasites (Fig. 4). ...
Fungi are a highly diverse group of heterotrophic eukaryotes characterized by the absence of phagotrophy and the presence of a chitinous cell wall. While unicellular fungi are far from rare, part of the evolutionary success of the group resides in their ability to grow indefinitely as a cylindrical multinucleated cell (hypha). Armed with these morphological traits and with an extremely high metabolical diversity, fungi have conquered numerous ecological niches and have shaped a whole world of interactions with other living organisms. Herein we survey the main evolutionary and ecological processes that have guided fungal diversity. We will first review the ecology and evolution of the zoosporic lineages and the process of terrestrialization, as one of the major evolutionary transitions in this kingdom. Several plausible scenarios have been proposed for fungal terrestralization and we here propose a new scenario, which considers icy environments as a transitory niche between water and emerged land. We then focus on exploring the main ecological relationships of Fungi with other organisms (other fungi, protozoans, animals and plants), as well as the origin of adaptations to certain specialized ecological niches within the group (lichens, black fungi and yeasts). Throughout this review we use an evolutionary and comparative‐genomics perspective to understand fungal ecological diversity. Finally, we highlight the importance of genome‐enabled inferences to envision plausible narratives and scenarios for important transitions.
... Predation has evolved multiple times in Fungi, though the exact number of times it has evolved remains to be determined. Predation has evolved in Ascomycota ( Yang et al. 2012;Baral et al. 2018), Basidiomycota (Dreschler 1935c; Barron and Dierkes 1977;Saikawa et al. 1994;Thorn et al. 2000;Luo et al. 2004;Zohar et al. 2013), and Zoopagomycota ( White et al. 2006;Corsaro et al. 2018). ...
Previous genome-scale phylogenetic analyses of Fungi have under sampled taxa from Zoopagales; this order contains many predacious or parasitic genera, and most have never been grown in pure culture. We sequenced the genomes of 4 zoopagalean taxa that are predators of amoebae, nematodes, or rotifers and the genome of one taxon that is a parasite of amoebae using single cell sequencing methods with whole genome amplification. Each genome was a metagenome, which was assembled and binned using multiple techniques to identify the target genomes. We inferred phylogenies with both super matrix and coalescent approaches using 192 conserved proteins mined from the target genomes and performed ancestral state reconstructions to determine the ancestral trophic lifestyle of the clade. Our results indicate that Zoopagales is monophyletic. Ancestral state reconstructions provide moderate support for mycoparasitism being the ancestral state of the clade.
... Traps of adhesive hyphae are restricted to the genera Stylopage and Cystopage of Zygomycetes (58), while stephanocysts are restricted to the genus Hyphoderma of Basidiomycota (51). Spiny balls and acanthocytes are only formed, respectively, by Coprinus comatus (53,54) and Stropharia rugosoannulata (59) in Agaricales of Basidiomycota. The sexual morphs of most nematodetrapping species are now assigned to Orbilia, and their type of trapping apparatus can be used as robust indicators of generic delimitation. ...
Nematode-Trapping Fungi, Page 1 of 2
Abstract
There are about 700 species of taxonomically diverse fungi that are be able to attack living nematodes (juveniles, adults, and eggs) and use them as a nutrient source ( 1 , 2 ). The most important genera include Purpureocillium, Pochonia, Hirsutella, Nematophthora, Arthrobotrys, Drechmeria, Fusarium, and Dactylellina ( 3 , 4 ). Among these nematophagous fungi, only a few species are obligate parasites of nematodes, but the majority are facultative saprophytes ( 5 – 7 ). Based on the mechanisms by which they attack nematodes, these nematophagous fungi are usually divided into four general groups: (i) nematode-trapping fungi that use specialized trapping structures differentiated from hyphae; (ii) endoparasitic fungi that use their spores; (iii) the opportunistic fungi that invade or colonize nematode eggs, females, or cysts with their hyphal tips; and (iv) toxin-producing fungi that immobilize nematodes before invasion ( 1 , 8 ). Nematophagous fungi are important natural enemies of nematodes in soil ecosystems. In recent decades, environmental and health concerns over the use of chemical nematicides have greatly increased the demand for the development of biological control agents in plant protection. The reason for the growing interest in nematophagous fungi is mostly their potential as biocontrol agents against plant- and animal-parasitic nematodes. So far, a substantial number of myconematocides have been developed worldwide ( 3 , 4 , 6 ).
... These devices are used to capture nematodes by means of an adhesive layer covering part or all of the device surface (Yang et al. 2007). According to Luo et al. (2004), some of the fungi immobilize or kill nematodes by releasing toxins. Fungi in the genera Harposporium, Nematoctonus and Meria are known to parasitize nematodes (Jansson et al. 1985). ...
... These devices are used to capture nematodes by means of an adhesive layer covering part or all of the device surface ( Yang et al. 2007). According to Luo et al. (2004), some of the fungi immobilize or kill nematodes by releasing toxins. Fungi in the genera Harposporium, Nematoctonus and Meria are known to parasitize nematodes ( Jansson et al. 1985). ...
The diversity of nematode destroying fungi in Taita Taveta, Wundanyi division, Coast Province, Kenya, was investigated between May 2006 and December 2007 aiming at harnessing their potential in the biological control of plant parasitic nematodes in the area. Given that the intensity of land cultivation is continually increasing in the study area, it is prudent to document the status of the nematode destroying fungi before the remaining forest habitats are ultimately disrupted. Soil samples were collected from forest, maize/bean, napier grass, shrub and vegetable fields, which represented the main land use types in the study area. The soil sprinkle technique method was used to isolate the nematode destroying fungi from the soil. The fungi were identified to species level. Eighty-five isolates, distributed in eight genera and 14 taxa were identified as nematode destroying fungi. The species identified were Arthrobotrys dactyloides, Arthrobotrys oligospora, Arthrobotrys superba, Acrostalagamus obovatus, Dactyllela lobata, Harposporium aungulilae, Harposporium liltiputanum, Harposporium spp, Haptoglosa heterospora, Monacrosporium asterospernum, Monacrosporium cianopagum, Myzocytium, spp, Nematoctonus georgenious and Nematoctonus leptosporus. Vegetable land use had the highest diversity of nematode destroying fungi. The results show that the study area is rich in nematode destroying fungi with A. oligospora being widespread and a possible candidate for biological control of plant parasitic nematodes.
Plant parasitic nematodes (PPNs) are one of the most serious constraints in food security. Among the many biocontrol agents studied for managing PPNs, nematophagous fungi show a high potential. These fungi control/suppress the nematode population either by parasitising or predating/trapping various nematode stages or kill them by secretion of nematotoxic metabolites. With more than 700 species of nematophagous fungi identified with a potential of nematode biocontrol, species such as Purpureocillium (Paecilomyces) lilacinus, Pochonia (Verticillium) chlamydosporia and Trichoderma are exploited as nematode parasitic fungi. Among nematode-trapping fungi, Arthrobotrys oligospora is widely used in nematode management. Along with parasitic and trapping species, Arbuscular mycorrhizal fungi (AMF) also offer an exciting opportunity to be integrated in nematode management programs due to their ability to induce systemic resistance and tolerance, competition for space and nutrients. In this chapter we discuss the mechanisms employed by nematophagous fungi in detail. We suggest that formulations incorporating 2 or more fungi with different modes of action should be commercialised to increase efficiency. Due to the enormous demand and availability of spurious products, strict regulations are necessary, nationally and internationally, to benefit the farming community facing PPNs threats.
The phylogenetic position of several clitocyboid/pleurotoid/tricholomatoid genera previously considered incertae sedis is here resolved using an updated 6-gene dataset of Agaricales including newly sequenced lineages and more complete data from those already analyzed before. Results allowed to infer new phylogenetic relationships, and propose taxonomic novelties to accommodate them, including up to ten new families and a new suborder. Giacomia (for which a new species from China is here described) forms a monophyletic clade with Melanoleuca (Melanoleucaceae) nested inside suborder Pluteineae, together with the families Pluteaceae, Amanitaceae (including Leucocortinarius), Limnoperdaceae and Volvariellaceae. The recently described family Asproinocybaceae is shown to be a later synonym of Lyophyllaceae (which includes also Omphaliaster and Trichocybe) within suborder Tricholomatineae. The families Biannulariaceae, Callistosporiaceae, Clitocybaceae, Fayodiaceae, Macrocystidiaceae (which includes Pseudoclitopilus), Entolomataceae, Pseudoclitocybaceae (which includes Aspropaxillus), Omphalinaceae (Infundibulicybe and Omphalina) and the new families Paralepistaceae and Pseudoomphalinaceae belong also to Tricholomatineae. The delimitation of the suborder Pleurotineae (= Schizophyllineae) is discussed and revised, accepting five distinct families within it, viz. Pleurotaceae, Cyphellopsidaceae, Fistulinaceae, Resupinataceae and Schizophyllaceae. The recently proposed suborder Phyllotopsidineae (= Sarcomyxineae) is found to encompass the families Aphroditeolaceae, Pterulaceae, Phyllotopsidaceae, Radulomycetaceae, Sarcomyxaceae (which includes Tectella), and Stephanosporaceae, all of them unrelated to Pleurotaceae (suborder Pleurotineae) or Typhulaceae (suborder Typhulineae). The new family Xeromphalinaceae, encompassing the genera Xeromphalina and Heimiomyces, is proposed within Marasmiineae. The suborder Hygrophorineae is here reorganized into the families Hygrophoraceae, Cantharellulaceae, Cuphophyllaceae, Hygrocybaceae and Lichenomphaliaceae, to homogenize the taxonomic rank of the main clades inside all suborders of Agaricales. Finally, the genus Hygrophorocybe is shown to represent a distinct clade inside Cuphophyllaceae, and the new combination H. carolinensis is proposed.
Plant parasitic nematodes (PPN) are ubiquitous in agricultural soils. They damage a range of vegetables as well as other agricultural crops worldwide. Some predaceous fungi, which act as nematode’s natural enemies, are one of the best pest management remedies. Some of these microbes create traps, resulting in the eelworms getting trapped and killed. Other predacious fungi behave as parasites inside the nematodes, producing poisons and virulence components that kill the nematodes internally. In order to develop powerful biological control agents against nematodes, it is crucial to understand the underlying principles of microbe-nematode interactions. In addition to focusing on the methods by which predaceous fungi infect worms and the nematode defence against dangerous infections, this book chapter reviews recent developments in our understanding of the interactions between nematodes and predaceous fungi. This chapter comprises important topics for more research and development, including prospective plans for applying our most recent findings to create efficient biocontrol methods for managing root-knot diseases of vegetables.
Vegetables are the richest source of vitamins, essential elements, and minerals like calcium and iron. Most of the human population are vegetarians; they fulfil their daily nutrient requirements by consuming vegetables. However, the production of vegetables is seriously hampered by several biotic stresses, viz., bacteria, fungi, nematodes, and viruses, which pose a considerable challenge to meeting future demands for such a large population. Among several biotic stresses, root-knot nematodes (RKNs) (Meloidogyne spp.) are the major threat to vegetable production. RKNs are obligate and sedentary root endoparasites of almost all vegetable crops and are considered the most damaging pests in agriculture. Since RKNs target the root vascular system, they provoke host nutrient deprivation and defective food and water transport by forming galls in the roots. They also cause aboveground symptoms of growth stunting, wilting, chlorosis in patches, and reduced crop yields. Besides the direct damage, RKNs act as a predisposing agent to other soil-borne bacterial and fungal pathogens and aggravate the problem, further leading to development of disease complexes. Considering the difficulties, researchers worldwide find eco-friendly approaches to protect vegetable production from such tiny and more damaging soil-borne pathogens.
Mycelium from the Yantardakh Lagerstätte (Santonian of Taimyr) is reported. Its hyphae are arranged mostly parallel, weakly branched and septated. The clamp connections indicate the Basidiomycota affinity. Two types of outgrowths are formed on the mycelium, located perpendicular to the parent hypha: the former rather long and common; and the latter are short peg-shaped, formed with a lower frequency. Arthroconidia and large spherical structures, looking like exudate drops are observed upon hyphae. Hyphae rings similar to the trapping loops of extant Basidiomycota have been found. Altogether, these rings, numerous drops and peg-like hyphal outgrowths may be interpreted as this mycelium belongs to nematophagous fungus of Agaricomycetes. Thus, this is the first finding of mycelium putatively nematophagous Basidiomycota from the Cretaceous of North Asia, which also implies the presence of nematodes in the Taimyr amber forest.
IntroductionP. florida is one of the edible fungi in the genus Pleurotus that have been shown to produce toxins with nematotoxicity. Realizing the importance of managing one of the most important plant-parasitic nematodes, Meloidogyne incognita in an ecofriendly way, P. florida has been studied in detail.Methods
The methods included obtaining and preparing the nematode inoculum. P. florida was isolated on Potato dextrose agar media and culture filtrate (cfP) was prepared from it to study the interaction between second-stage juveniles and cultural filtrate of Pleurotus florida (cfP) in vitro. Interaction between second-stage juveniles and P. florida was also studied in culture medium. Urtica dioica green manure was prepared under greenhouse conditions. In vitro test was done to assess the compatibility of Urtica dioica with P. florida before evaluating the combined effect of Spent Mushroom Substrate (SMS) of P. florida and U. dioica green manure (GM) on the population of M. incognita under glasshouse condition.ResultsThe immobilization of second-stage juveniles (J2) by the fungus P. florida was found inversely proportional to the time period of incubation. Whereas, the trapping of J2 by the fungus P. florida and the time period of incubation was found directly proportional. It was found that the paralysis of J2 decreased with the increase in dilutions of cultural filtrate. The overall increase in growth parameters of tomato and decrease in reproduction parameters of M. incognita was found in the treatment where 60g GM and 100g SMS was used per 2 kg of nematode infested soil.Conclusion
The findings revealed that P. florida is nematophagous and its spent mushroom substrate could be useful for M. incognita biocontrol. M. incognita population in the soil can be reduced drastically when used with other soil amendments and hence U. dioica, a common weed can be used as a green manure crop which improves the efficacy of P. florida.
Nematodes and fungi are soil inhabitants. Both are essential for maintaining the stability of food-web and facilitation of the nutrient cycle. Interaction between nematodes and fungi is possible in multiple ways. Here, we supply a platform for nematophagous (nematode destroying) fungi (NF), their mode of action, and their importance in agricultural ecosystems. They are potentially important for sustainable agriculture and play a major role in integrated pest management programs. Nematophagous fungi belong to a broad taxonomic group, such as Ascomycota, Oomycota, Basidiomycota, and distinct groups of fungi. Nematophagous fungi are broadly distributed in terrestrial and aquatic ecosystems that contain high densities of nematodes. Depending on the mechanism that affects nematode, NF can be divided into four types. Here, we described the classification, taxonomy, occurrence, distribution and ecology, types of nematophagous fungi, and potential mechanisms of NF in the control of plant-parasitic nematodes.KeywordsPlant-parasitic nematodesNematophagousBiological control
Arthrobotrys oligospora
Egg parasitesSecond-stage juveniles
Mit über 92.000 Arten sind die Ascomycota (Schlauchpilze) mit Abstand die größte Abteilung der Fungi. Wir gehen davon aus, dass es zudem innerhalb dieser Gruppe noch sehr viele bisher nicht entdeckte Arten gibt.
Root-knot nematodes (Meloidogyne spp.) are sedentary endoparasites and soil-borne pathogens worldwide. M. incognita is one of the most devastating and dominant species among them causing economic yield losses in almost all vegetables and other agricultural crops in the world. Current management strategies against M. incognita are not sufficient. However, from the last decades, utilization of nematicides has been increasing to manage this pest due to which environmental and human health issues arises. Bio-organic approaches are the best alternatives to nematicides, including biological agents and organic matters. In bio agents both arbuscular mycorrhizal and nematophagous fungi have a potent ability to manage plant-parasitic nematodes by inducing systemic resistance and activation of pathogenesis related (PR) genes in inoculated plants against nematodes, whereas nematophagous fungi trap nematodes for their feeding and killing them. Soil application of organic matters viz., botanical extract, oil cakes and agricultural wastes both in vitro and in vivo is also useful. Botanical extracts, oil cakes, kill nematodes by releasing secondary metabolites and inhibiting the movement of juveniles in the soil. Researchers from all over the world engage in evolving eco-friendly approaches that enhance and sustain the vegetable and agricultural production against this pest and keep it below the threshold level without affecting beneficial soil microbiota. In the future, such environment benign approaches have become an active field of research that adds new knowledge for their success against pest management, and enhancement of agricultural production for the human population.
Background
Root-knot nematodes in general and Meloidogyne incognita , in particular, are pests that cause agricultural losses. Currently, nematode control relies on chemical nematicides, which are hazardous to the environment and human health. The increasing demand for ecofriendly nematicides has prompted researchers to look into biocontrol agents that act as efficient and long-lasting alternatives to the currently used chemicals.
Objective
The aim of the study was to evaluate the in-vitro nematicidal activity of eight mushroom ( Cordyceps militaris , Metacordyceps neogunnii , Hericium erinaceus , Dictyophora indusiata , Cerioporus squamosus , Tirmania nivea , Tirmania pinoyi , and Agaricus impudicus ) extracts against M. incognita juveniles and eggs.
Materials and methods
Hydromethanolic extracts were prepared from the fruiting bodies of mushrooms under investigation. Then the obtained extracts were evaluated for their in-vitro nematicidal activity against M. incognita juveniles’ second stage after 24, 48, and 72 h of treatment, also against their eggs.
Results and conclusion
All tested mushroom extracts were capable of inducing mortality in M. incognita second stage juveniles with mortality percentages ranging from 79.3 to 97%. On the other hand, the tested mushroom extracts exhibited some nematostatic and nematicidal activity against M. incognita eggs as compared with the control after 7 days using 80 µl/ml concentration. The tested mushroom extracts caused suppression in M. incognita eggs hatching with inhibition rates that ranged from 59.38 to 81.25%. A. impudicus hydromethanolic extract showed the highest inhibition as compared with the control and other tested mushroom extracts as it caused a relative suppression that reached 81.25% against M. incognita eggs after 7 days of exposure. The same mushroom extract has achieved a juveniles mortality of 97%. A. impudicus extract is nominated as a potential nematicidal agent. Further studies are required to confirm the potency of this extract and analyze its chemical profile.
Fungi are very important microorganisms that are potentially utilized in different fields such as in agriculture and others. Fungi interact with plants as a useful factor or harmful factor. Useful fungi display a big role in agriculture sustainability. These fungi are of many types such as endophytic fungi and symbiosis fungi. The role of beneficial fungi in the control of pests, weeds, and plant pathogens can be an alternative to chemical pesticides. The beneficial fungi can be in different groups but, in general, comprise mycorrhiza, endophytic fungi, entomopathogenic fungi, mushroom, and dark septate fungi. Useful fungi contain some important tools between non-mycoparasitism and mycoparasitism. Some tools show high efficiency in the reduction of plant diseases such as producing secondary metabolites and induced plant defenses and systemic resistance. Also, some useful fungi have potential to enhance plant growth. The importance of fungi used in the fields that encouraged to inter them in the industry to produce the biopesticides and biofertilizers which can be instead of using synthetic chemicals and more reducing the residue of chemicals in environmental. In conclusion, the big role for fungi can utilize in the agriculture sustainable by including into the integrated management for plant pathogens, and pests.
Mushrooms degrade matter to produce metabolite for sustaining life. For degradation they produce enzymes and certain metabolites. Both the enzymes and the metabolites are of use for human. The metabolites have medicinal applications. The traditional use and the scientific work on some traditionally used medicinal mushrooms have been discussed here. Some of the mushrooms are Auricularia delicata, A. polytricha, A. auricular, Agaricus blazei, Coprinus comatus, Cordyceps spp., Fomes fomentarius, Fomitopsis pinicola, Ganoderma lucidum, etc. Auricularia delicata has been used in the traditional medicine of Manipur, India, for dysentery and liver healing therapy. A scientific investigation done by one of the authors on traditionally used Auricularia species showed its hepatoprotective activity. The compound isolated from the ethyl acetate extract was chlorogenic acid. It is known to have hepatoprotective activity. This has been a good example illustrating that traditional medicine is a good lead to drug discovery.
Acanthocytes are special cells with a distinct spiky shape produced exclusively by the fungi of Stropharia and can be used to defend against nematodes. In the present study, the ultrastructure and development of acanthocytes were revealed by scanning electron microscopy (SEM) and cryo-SEM in S. rugosoannulata, a popular cultivated mushroom both in China and Europe. The acanthocytes were abundant on the surface of rhizomorph, casing soils, and vegetative mycelia of homokaryotic and heterokaryotic strains in S. rugosoannulata. The development of the acanthocyte was investigated with cryo-SEM, which has distinct advantage for observation of the ultrastructure of live, hydrated structures. Three distinct stages, including formation of lateral branch that was covered with patches, spiky structure formation, and maturation of acanthocytes, were identified and described. The irregular patches deposited on the surface of lateral branches and the holes in the spiky branches of the acanthocytes were reported for the first time. The environmental nitrogen level showed impact on acanthocyte production, but it seemed not to be the indispensable factor. Acid medium could delay the initiation of the acanthocyte formation but did not affect the overall morphology and structure, indicating that the central deposit of acanthocytes should be acid soluble. Acanthocytes of S. rugosoannulata have similar hydrophobicity to mycelia. The observation of ultrastructure and development process of acanthocytes provides insights into the ecological function and evolution of this special structure.
Environmental and health concerns over the use of chemical pesticides have increased the need for alternative measures in the control of plant-parasitic nematodes. Biological control is considered ecologically friendly and a possible alternative in pest and disease management. Several organisms are known to be antagonistic against plant parasitic nematodes. Fungal biological control is an exciting and rapidly developing research area and there is growing attention in the exploitation of fungi for the control of nematodes. In this chapter, important nematode-parasitic and antagonistic fungi are divided into nematophagous and endophytic fungi, and their recent taxonomy, distribution, ecology, biology and their mode of action are discussed.
Plant-parasitic nematodes are a serious threat to global agriculture. Although the control of plant-parasitic nematodes mainly depends on chemical methods, the need for environmentally friendly alternative approaches for the control of nematodes has been realized in the recent past. In order to find alternative methods to control plant-parasitic nematodes, endophytic microorganisms have been extensively studied in various plant species. These studies have used an array of molecular techniques from simple PCR to next-generation sequencing approaches. Metagenomic studies of endophytes are believed to be the most advanced and effective techniques to disentangle and understand interactions between endophytes and plant-parasitic nematodes.
The present paper reviewed publications on the nematocidal activity of edible mushrooms (EM) and their potential use as sustainable tools for the control of parasitic nematodes affecting agriculture and livestock industry. Nematodes are organisms living in the soil and animals’ guts where they may live as parasites severely affecting economically important crops and farm animals, thus causing economic losses to worldwide agriculture. Traditionally, parasitic nematodes have been controlled using commercial pesticides and anthelmintic (AH) drugs. Over the years, nematodes developed resistance to the AH drugs, reducing the usefulness of many commercial drugs. Also, the use of pesticides/anthelmintic drugs to control nematodes can have important negative impacts on the environment. Different EM have been not only used as food but also studied as alternative methods for controlling several diseases including parasitic nematodes. The present paper reviewed publications from the last decades about the nematocidal activity of EM and assessed their potential use as sustainable tools for the control of nematodes affecting agriculture and livestock industry. A reduced number of reports on the effect of EM against nematodes were found, and an even smaller number of reports regarding the potential AH activity of chemical compounds isolated from EM products were found. However, those studies have produced promising results that certainly deserve further investigation. It is concluded that EM, their fractions and extracts, and some compounds contained in them may have biotechnological application for the control of animal and plant parasitic nematodes.
Technologies are indispensable in our lives; one of the branches of the use of technologies is in agriculture. Today, sustainable and environmentally friendly technologies are necessary. In this task, the use of microorganisms is carried out which helps to provide a benefit to plant crops; in addition, there are biofertilizers, biostimulants, and biopesticides. Over the years, the consequences of the misuse of some chemicals and their bioaccumulation in the environment have been evidenced, affecting indispensable processes. For this reason, it is important to know the processes in the nature of microbial and takes advantage of its resources that are low impact and no toxic for the care of agricultural crops. This type of strategy has led new sciences to seek studies that provide this indispensable knowledge for the development of humanity taking care of its environment. We searched for information about science that seeks sustainable methods in agricultural crops, as well as several examples of the organisms used in these methods and the commercial form of how these available technologies can be found.
Nematode destroying fungi are potential biocontrol agent for management of plant-parasitic nematodes. They inhibit nematode population through trapping devices or by means of enzymes and metabolic products. They regulate nematode behavior by interfering plant-nematode recognition, and promote plant growth. For more effective biocontrol, thorough understanding of the biology of nematode destroying fungi, targeted nematode pest and the soil ecology and environmental condition in the field is necessary. This review highlights different types of nematode destroying fungi, their mode of action as well as commercial products based on reports published in this area of research.
Knowledge of nematophagous fungi has increased dramatically over recent years, particularly with the advancement of molecular biology and omics sciences. However, most of this knowledge is restricted to the three traditional groups of nematophagous fungi: predatorial, opportunistic or ovicidal and endoparasitic. The present study supported the proposed classification of nematophagous fungi into five groups: nematode-trapping/predators, opportunistic or ovicidal, endoparasites, toxin-producing fungi and producers of special attack devices. This study also highlighted the analogy between special attack devices and real medieval weapons. Much study remains to be done to better understand some fungi and to discover new fungi with nematophagous and biological control potential.
Pathogens embedded in biofilms are involved in many infections and are very difficult to
treat with antibiotics because of higher resistance compared to planktonic cells.
Therefore, new approaches for their control are urgently needed. One way to search for
biofilm dispersing compounds is to look at defense strategies of organisms exposed to
wet environments, which makes them prone to biofilm infections. It is reasonable to
assume that mushrooms have developed mechanisms to control biofilms on their
sporocarps (fruiting bodies). A preliminary screening for biofilms on sporocarps revealed
several species with few or no bacteria on their sporocarps. From the edible mushroom
Coprinus comatus where no bacteria on the sporocarp could be detected (3R,4S)-2-
methylene-3,4-dihydroxypentanoic acid 1,4-lactone, named coprinuslactone, was isolated.
Coprinuslactone interfered with quorum-sensing and dispersed biofilms of Pseudomonas
aeruginosa, where it also reduced the formation of the pathogenicity factors pyocyanin and
rhamnolipid B. Coprinuslactone also damaged Staphylococcus aureus cells in biofilms at
subtoxic concentrations. Furthermore, it inhibited UDP-N-acetylglucosamine enolpyruvyl
transferase (MurA), essential for bacterial cell wall synthesis. These two modes of action
ensure the inhibition of a broad spectrum of pathogens on the fruiting body but may also be
useful for future clinical applications.
Production of mitotic spores has been reported for various species of the Agaricomycetes but is generally rather neglected and the extent of asexual sporulation in this class of Basidiomycetes is unknown. The typical life cycle of Agaricomycetes comprises of two alternate mycelial stages, the sterile monokaryon and the fertile dikaryon. The monokaryon contains only one type of haploid nuclei. The dikaryon is formed by mating of two compatible monokaryons and has two distinct haploid nuclei in its hyphal cells, each one per parental monokaryon. Both types of mycelia may produce asexual spores but species differ in whether mitospores are formed at the monokaryon, at the dikaryon, at both or at none. Mitospores produced on the dikaryon might be homokaryotic or heterokaryotic. Here, we present an overview on species of the Agaricomycetes and their spores. Types of sporulation include thallic spore formation (arthroconidia), blastic sporulation (blastoconidia) and intracellular production of thick-walled chlamydospores. Where known, we discuss functions of spores and regulation of mitospore production.
Terrestrial fungi are commonly studied in the laboratory, growing on artificial media in which nutrients are typically homogeneously distributed and supplied in superabundance, the environment is sterile and microclimate (temperature, moisture, gaseous regime) usually relatively constant. This contrasts with the natural environment, in which: nutrients are often patchily and sparsely distributed or not readily available, because they are locked in recalcitrant material (e.g. lignin); many other organisms are encountered, including other fungi, bacteria and invertebrates; and microclimate is constantly changing, both temporally and spatially. This chapter explores the ways in which fungi cope with environmental heterogeneity. Similar situations are faced by macroorganisms and analogies are drawn. Emphasis is placed on basidiomycetes, not only because they have been studied in most detail, but because of their dominant role as decomposers and mutualistic symbionts (Boddy & Watkinson, 1995; Smith & Read, 1997) and because they are better adapted to respond to environmental heterogeneity over scales ranging from micrometres to many metres than are other fungi. Both saprotrophic and ectomycorrhizal Basidiomycota form extensive mycelial systems in woodland soil and litter, but it is the former that are the focus of this review. Saprotrophic, cord-forming Basidiomycota that ramify at the soil–litter interface, interconnecting disparate litter components, provide most examples. The key feature of these fungi that fits them for growth in environments where resources are heterogeneously distributed is that they are non-resource-unit restricted, i.e. they can grow out of one resource in search of others. © Cambridge University Press 2007 and Cambridge University Press, 2009.
Traditional ethno-mycomedicinal practices involving macrofungi were documented using questionnaires from Jessore and Purna communities located in the Northern and Southern Gujarat. The quality of traditional knowledge within and in between the communities was compared by informant's consensus index factor calculated for each ailment. The possibility of any relation between the traditional practices and informant's consensus index factors was assessed as well. Alternately in order to classify the types of species usages, binary scores were allotted based on the presence or absence of species storage for later use, open sharing and specificity of the practices. Followed by this species scores were subjected to Euclidean distance dissimilarity matrix based hierarchical agglomerative clustering. In totality 23 species were documented addressing various ailments, of which 9 species were used to treat general aspects like convalescence, whereas others (14 species) were used for specific ailments. In the Jessore community 5 of the 7 ailments (41.2%) were related to skin problems, whereas in Purna community only 7 of 18 ailments (38.9%) had similar usage. The total ailments addressed and species documented from the Purna community had a greater diversity and bore higher informant's consensus index value in comparison to the Jessore community. Cause and effect of some abnormal informant's consensus values, rendering it dubious, are also discussed. Hierarchical agglomerative clustering revealed the influence of all the three aspects scored as above. The corner-stone species are more important than other species because they are necessary for the survival of the traditional know-how and well being of the communities engaging them and have applications. Moreover, depletion due to rampant use of such species calls upon there identification and conservation. This could be achieved to an extent by simple binary scores based clustering. Certain corner-stone species with closed (absence of) knowledge sharing were found to withhold specific practices. Those with general medicinal applications can be useful as nutraceuticals, whereas those with specific claims can be screened further in order to identify pharmaceutical potentials. In addition to this the present work mentions the documentation of traditional ethno-myco-medicinal practices of several species for the first time ever.
Hirsutella minnesotensis [Ophiocordycipitaceae (Hypocreales, Ascomycota)] is a dominant endoparasitic fungus by using conidia that adhere to and penetrate
the secondary stage juveniles of soybean cyst nematode. Its genome was de novo sequenced and compared with five entomopathogenic
fungi in the Hypocreales and three nematode-trapping fungi in the Orbiliales (Ascomycota). The genome of H. minnesotensis is 51.4 Mb and encodes 12,702 genes enriched with transposable elements up to 32%. Phylogenomic analysis revealed that H. minnesotensis was diverged from entomopathogenic fungi in Hypocreales. Genome of H. minnesotensis is similar to those of entomopathogenic fungi to have fewer genes encoding lectins for adhesion and glycoside hydrolases
for cellulose degradation, but is different from those of nematode-trapping fungi to possess more genes for protein degradation,
signal transduction, and secondary metabolism. Those results indicate that H. minnesotensis has evolved different mechanism for nematode endoparasitism compared with nematode-trapping fungi. Transcriptomics analyses
for the time-scale parasitism revealed the upregulations of lectins, secreted proteases and the genes for biosynthesis of
secondary metabolites that could be putatively involved in host surface adhesion, cuticle degradation, and host manipulation.
Genome and transcriptome analyses provided comprehensive understanding of the evolution and lifestyle of nematode endoparasitism.
Coprinus comatus is an edible and nematophagous basidiomycete fungus. The optimal culture conditions
for
the
filamentous
growth
and
density
of
6
strains
of
this
mushroom
were
investigated.
The
temperature
suitable
for
the
filamentous
growth
and
density
was
obtained
at
25
ºC and optimal range of temperature
was 20~30 ºC. This mushroom showed a broad pH range (5~9) for its mycelial growth and density. The mostly favorable growth was found at pH 7. According to filamentous growth Czapek’s, PDA, YM, and Hamada were the most suitable, and Hennerberg and Hoppkins were the most unfavorable for this mushroom.
Among
10
different
carbon
sources,
sucrose
and
sorbitol
were
the
best
but
lactose
and
xylose
were
the
most
unfavorable
carbon
sources.
In all carbon sources, mycelial density was found to be compact. The most suitable nitrogen source was arginine and glycine but the most unsuitable was histidine for the mycelial
growth. The mycelial density in nitrogen source containing medium was found to be different on the culture media.
Arthrobotrys oligospora, a predacious fungus of nematodes, has been very useful in understanding the relationship between nematophagous fungi and their nematode hosts. Arthrobotrys oligospora is by far the most common nematode-trapping fungus with the characteristic ability of forming adhesive trapping nets once in contact with nematodes. This review highlights the versatility and development of A. oligospora as a system to identify and characterize the ecology and biology of nematode-trapping fungi. Using A. oligospora, advances in our knowledge of nematophagous fungi have been made through the discovery of special traits and virulence determinants involved in the pathogenic process, or by creating new ways of presenting these factors to the target nematodes. We argue for an increased role for A. oligospora in complementing other model systems in biological control research.
Environmental and health concerns over the use of chemical pesticides have increased the need for alternative measures in
the control of plant-parasitic nematodes. Biological control is considered ecologically friendly and a possible alternative
in pest and disease management. Several organisms are known to be antagonistic against plant parasitic nematodes. Fungal biological
control is an exciting and rapidly developing research area and there is growing attention in the exploitation of fungi for
the control of nematodes. In this chapter important nematode parasitic and antagonistic fungi are divided into nematophagous
and endophytic fungi, and their taxonomy, distribution, ecology, biology and their mode of action are discussed.
Nematophagous fungi are potential candidates for biological control of plant-parasitic nematodes, and an important constituent
in integrated pest management programs. In this chapter we describe various aspects on the biology of these fungi. Nematophagous
species can be found in most fungal taxa, indicating that the nematophagous habit evolved independently in the different groups
of nematophagous fungi. Regarding their mode of action we discuss recognition phenomena (e.g. chemotaxis and adhesion), signaling
and differentiation, and penetration of the nematode cuticle/eggshell using mechanical, as well as enzymatic (protease and
chitinase) means. The activities of nematophagous fungi in soil and rhizosphere is also discussed.
Plant-parasitic nematodes cause significant economic losses to a wide variety of crops. Chemical control is a widely used option for plant-parasitic nematode management. However, chemical nematicides are now being reappraised in respect of environmental hazard, high costs, limited availability in many developing countries or their diminished effectiveness following repeated applications. This review presents progress made in the field of microbial antagonists of plant-parasitic nematodes, including nematophagous fungi, endophytic fungi, actinomycetes and bacteria. A wide variety of microorganisms are capable of repelling, inhibiting or killing plant-parasitic nematodes, but the commercialisation of these microorganisms lags far behind their resource investigation. One limiting factor is their inconsistent performance in the field. No matter how well suited a nematode antagonist is to a target nematode in a laboratory test, rational management decision can be made only by analysing the interactions naturally occurring among “host plant–nematode target–soil–microbial control agent (MCA)–environment”. As we begin to develop a better understanding of the complex interactions, microbial control of nematodes will be more fine-tuned. Multidisciplinary collaboration and integration of biological control with other control methods will␣also contribute to more successful control practices.
Many bacteria and fungi are known to degrade cellulose in culture, but their combined response to cellulose in different soils
is unknown. Replicate soil microcosms amended with [13C]cellulose were used to identify bacterial and fungal communities responsive to cellulose in five geographically and edaphically
different soils. The diversity and composition of the cellulose-responsive communities were assessed by DNA-stable isotope
probing combined with Sanger sequencing of small-subunit and large-subunit rRNA genes for the bacterial and fungal communities,
respectively. In each soil, the 13C-enriched, cellulose-responsive communities were of distinct composition compared to the original soil community or 12C-nonenriched communities. The composition of cellulose-responsive taxa, as identified by sequence operational taxonomic unit
(OTU) similarity, differed in each soil. When OTUs were grouped at the bacterial order level, we found that members of the
Burkholderiales, Caulobacteriales, Rhizobiales, Sphingobacteriales, Xanthomonadales, and the subdivision 1 Acidobacteria were prevalent in the 13C-enriched DNA in at least three of the soils. The cellulose-responsive fungi were identified as members of the Trichocladium, Chaetomium, Dactylaria, and Arthrobotrys genera, along with two novel Ascomycota clusters, unique to one soil. Although similarities were identified in higher-level taxa among some soils, the composition
of cellulose-responsive bacteria and fungi was generally unique to a certain soil type, suggesting a strong potential influence
of multiple edaphic factors in shaping the community.
Methanol extracts of various plant parts of Ailanthus altissima were tested against the root knot nematode Meloidogyne javanica . Extracts of bark (ABE), wood (AWE), roots (ARE), and leaves (ALE) from A. altissima were investigated against freshly hatched second-stage juveniles (J(2)). AWE was the most active extract, with EC(50/3d) of 58.9 mg/L, while ALE, ARE, and ABE did not show nematicidal activity. The chemical composition of the extracts of A. altissima was determined by gas chromatography-mass spectrometry, and (E,E)-2,4-decadienal, (E)-2-undecenal, (E)-2-decenal, hexanal, nonanal, and furfural were the most prominent constituents. (E,E)-2,4-Decadienal, (E)-2-decenal, and furfural showed the highest nematicidal activity against M. javanica , with EC(50/1d) = 11.7, 20.43, and 21.79 mg/L, respectively, while the other compounds were inactive at the concentrations tested. The results obtained showed that AWE and its constituents (E,E)-2,4-decadienal and (E)-2-decenal could be considered as potent botanical nematicidal agents.
The gene encoding an extracellular serine protease was cloned from Arthrobotrys multisecundaria using degenerate primers. The gene was highly similar (99.26%) to protease Mix from Monacrosporium microscaphoides. To clarify the taxonomic relationship between these species, genes encoding the internal transcribed spacer (ITS) and beta-tubulin were also cloned and sequenced from A. multisecundaria and M. microscaphoides, respectively. Homologous analysis of the nuclear (ITS) and protein (beta-tubulin) encoding genes showed that the two species of nematode-trapping fungi also shared extensive identity (99.82 and 99.63%, respectively), although they exhibited obvious differences in secondary conidia morphology. Accordingly, a taxonomic revision is recommended, with A. multisecundaria being revised as A. microscaphoides var. multisecundaria. In addition, the identified mutation may better facilitate the study of the sporulation of nematode-trapping fungi.
To better exploit the biocontrol potential of nematophagous fungi, it is important to fully understand the molecular background of the infection process. In this paper, several nematode-trapping fungi were surveyed for nematocidal activity. From the culture filtrate of Monacrosporium microscaphoides, a neutral serine protease (designated Mlx) was purified by chromatography. This protease could immobilize the nematode Penagrellus redivivus in vitro and degrade its purified cuticle, suggesting that Mlx could serve as a virulence factor during infection. Characterization of the purified protease revealed a molecular mass of approximately 39 kDa, an isoelectric point of 6.8, and optimum activity at pH 9 at 65 degrees C. Mlx has broad substrate specificity, and it hydrolyzes protein substrates, including casein, skimmed milk, collagen, and bovine serum albumin. The gene encoding Mlx was also cloned and the nucleotide sequence was determined. The deduced amino acid sequence contained the conserved catalytic triad of aspartic acid--histidine--serine and showed high similarity with two cuticle-degrading proteases (PII and Aoz1), which were purified from the nematode-trapping fungus Arthrobotrys oligospora. Research on infection mechanisms of nematode-trapping fungi has thus far only focused on A. oligospora. However, little is known about other nematode-trapping fungi. Our report is among the first to describe the purification and cloning of an infectious protease from a different nematode-trapping fungus.
Stephanocysts are described and illustrated and their taxonomic value is elucidated. A description of Hyphoderma tenue (Pat.) Donk is also presented.
A nematicidal toxin was purified fromPleurotus ostreatus NRRL 3526 grown on moistened, autoclaved wheat straw for 30 days at room temperature (21-33°C). The active compound, at a concentration of 300 ppm, immobilized 95% of test nematodes (Panagrellus redivivus) within 1 hr. Immobilized nematodes did not recover, even after being rinsed with deionized water. The toxin was identified astrans-2-decenedioic acid.
Eighteen species of resupinate fungi belonging to Hyphoderma (Corticiaceae) attacked and consumed nematodes by two different mechanisms. Seven Hyphoderma spp. (H. baculorubrense, H. guttuliferum, H. macronatum, H. praetermissum, H. puberum, H. rude, and H. tenue) used adhesive stephanocysts to adhere to, capture, infect, and destroy their prey, whereas 11 Hyphoderma spp. (H. albicans. H. amoenum, H. heterocystidium, H. medioburiensis, H. mutatum, H. obtusiforme, H. pallidum, H. populneum, H. radula, H. setigerum, and H. typhicola) lacked stephanocysts and destroy and consumed mycophagous nematodes after they ingested the fungal mycelium [...]
On water agar, Conocybe lactea (Lange) Metrod produces droplets of toxin on conspicuous secretory cells. Both free-living rhabditoid nematodes and fungus-feeding nematodes (Aphelenchoides sp.) are immobilized when they contact the toxin droplets. Prolonged and (or) repeated exposure to the toxin results in death of the nematodes, which may take place at some distance from the contact point. Unlike Pleurotus ostreatus (Jacq.:Fr.) Kummer, the hyphae of C. lactea do not locate and colonize immobilized nematodes and (or) consume them as a nutrient source. It is considered that the toxin droplets are for protection of the hyphal system and function as antifeedants to repel or kill fungus-feeding nematodes and possibly other fungus-feeding soil microfauna. No differences were observed in nematode response between dikaryotic and monokaryotic cultures, although the latter produced a spermatial-like arthrosporic anamorph. Panaeolina foenisecii (Pers.:Fr.) R. Maire also produces secretory cells with fluid droplets. These droplets, however, are not as toxic to nematodes as those of C. lactea. Keywords: secretory cells, nematotoxin, antifeedants, lawn mushroom.
Basidiospores of Hyphoderma praetermissum frequently produced stephanocysts upon germination. Stephanocyst ontogeny was studied with scanning and transmission electron microscopy. A hypothesis concerning the function of stephanocysts is presented.
Stephanocysts are described and illustrated and their taxonomic value is elucidated. A description of Hyphoderma tenue (Pat.) Donk is also presented.
Ten species of gilled fungi, including the oyster mushroom (Pleurotus ostreatus), have been shown to attack and consume nematodes. It is suggested that these wood-decay fungi utilize the nutrients in their prey to supplement the low levels of nitrogen available in wood. This mode of nutrition is similar in principle to that of carnivorous higher plants.
Nematophagous fungi: the perfect state of
- G L Barron
- Y Dierkes
A manual for research on a potential biological control agent for root-knot nematodes. Merckstr, Germany: Druckform GmbH
- B R Kerry
- J M Bourne
A nematode-capturing fungus with anastomosing clamp-bearing hyphae