Mycoparasitism

A mycoparasite is an organism with the ability to be a parasite to fungi. A variety of fungicolous fungi have been found in nature, either as parasites, commensals or saprobes.[1] Biotrophic mycoparasites get nutrients from living host cells. Necrotrophic mycoparasites rely on decayed matter (saprophytic growth).[1][2]

Types of mycoparasitism

Biotrophic mycoparasites and nectrophic mycoparasites are two main groups of mycoparasite.[3]

Biotrophic and necrotrophic mycoparasites

Biotrophic mycoparasites get nutrients from living host cells and their growth of these parasites is greatly influenced by the metabolism of the host.[4] Biotrophic mycoparasites tend to have a high host specificity, and often form specialized infection structures or a host parasite transition.[5] Necrotrophic mycoparasites could only rely on saprophytic growth.[2] On the other hand, the antagonistic action is strongly aggressive in necrotrophic relationships which is dominated by necrotrophic mycoparasites. Necrotrophic parasites tend to have a low host specificity, and are relatively unspecialized in their mechanism of parasitism.[5]

Balanced and destructive mycoparasites

Balanced mycoparsites have little or no destructive effect on the host, whereas destructive mycoparasites have the opposite effect.[6] Biotrophic mycoparasites are generally considered as balanced mycoparasites; Necrotrophic mycoparasites usually have low host specificity and could use toxic and related enzyme to kill host, therefore necrotrophic mycoparasites are usually considered as destructive mycoparasites. However, in some combinations, the parasite may live during its early development as a biotrophic parasite, then kill their host and change into destructive mycoparasites in their late stage of parasitization.[4][6]

Myco-heterotrophy

Monotropa uniflora (or other angiosperm species), which are parasitic on fungus and do not photosynthesize, are sometimes classified as mycoparasites, however they should be referred to as myco-heterotrophs.

Mechanism

There are normally four continuous steps of mycoparasitism: target location; recognition; contact and penetration; nutrient acquisition.[7]

Target location

Many research indicate that the growth direction of mycelium, spore germination, and bud tube elongation of mycoparasites have tropic reaction or tropism before attaching the host fungi.[8] This tropic reaction is resulted from chemical stimulants secreted from mycohost and the direction of concentration gradient determines the growth direction of the parasite.[9] As the mycoparasitic interaction is host-specific and not merely a contact response, it is likely that signals from the host fungus are recognized by mycoparasites such as Trichoderma and provoke transcription of mycoparasitism-related genes.[10][11]

Recognition

When mycoparasites get attachment of mycohost, they will recognize each other. It is indicated that the recognition between mycoparasites and their host fungi is related to the agglutinin on the cell surface of the mycohost. The carbohydrate residues on the cell wall of mycoparasites could specifically bind to the lectins on the surface of the host fungi to achieve mutual recognition.[12]

Contact and penetration

Once mycoparasites and mycohost recognize each other, both of them would have some changes in external form and internal structure to some extents.[13][14] The manifestations of the mycoparasitic fungi are usually as follows: (1) the hypha grows rapidly on the host fungi and coils around the hypha of the host fungi; (2) the hypha penetrates and elongates the hypha of the host fungi (3) the infection filament is produced and penetrates the cells of host fungi to build parasitic relationship.[15] In terms of necrotrophic/destructive mycoparasites, on the other hand, the hyphae of host fungi, due to the role of mycoparasites, will stop the growth, deform, shrivel and even dissolve.[2]

Application

Recently, it is popular to use integrated pest management (IPM) as an approach to reduce the amount of pesticides used, through preventive cultural practices, the use of disease resistant plant cultivars, and the use of mechanical and biological control of pathogen populations. Biocontrol of plant pathogens by microbial antagonists is one promising component in future disease control strategies that is compatible with both organic agriculture and IPM.[16] As some mycoparasitic fungi have the ability to parasite and kill other fungi, these fungi could be used to antagonize plant pathogenic fungi directly as biocontrol agent. Mycoparasitism of plant pathogenic fungi by Trichoderma isolates has been well researched and is widely considered to be a major contributing factor to the biocontrol of a range of commercially important diseases.[7] In, among others, the United States, India, Israel, New Zealand, and Sweden have applied Trichoderma species commercially such as Rhizoctonia solani, Botrytis cinerea, Sclerotium rolfsii, Sclerotinia sclerotiorum, Pythium spp., and Fusarium spp. as a promising alternative to chemical pesticides.[17][18] Moreover, with the better understanding of mycoparasitism, more bioactive compounds including biopesticides and biofertilizers would be introduced as beneficial products.[19]

List of fungal bioagents with their trade and manufacturers name[5]

Commercial products	Bioagents used	Name of the manufacturer
AQ10 biofungicide	Ampelomyces quisqualis isolate M-10	Ecogen, Inc. Israel
Anti-Fungus	Trichoderma spp.	Grondortsmettingen De Cuester, Belgium
Biofungus	Trichoderma spp.	Grondortsmettingen De Cuester n. V.Belgium
Bas-derma	Trichoderma viride	Basarass Biocontrol Res. Lab., India
Binab T	Trichoderma harzianum (ATCC 20476) and Trichoderma polysporum (ATCC 20475)	Bio-Innovation AB, UK
Bioderma	Trichoderma viride/T. harzianum	Biotech International Ltd., India
Biofox C	Fusarium oxysporum (Non- pathogenic)	S. I. A. P. A., Italy
Prestop, Prirnastop	Gliocladium catenulatum	Kemira Agro. Oy, Finland
Root Pro, Root Prota to Soilgard	Trichoderma harzianum/Gliocladium virens strain GL-21	Efal Agr, Israel Thermo Trilogy, USA
Root shield, Plant shield, T-22 Planter box	Trichoderma harzianum Rifai strain KRL-AG (T-22)	Bioworks Inc., USA
Supresivit	Trichoderma harzianum	Borregaard and Reitzel, Czech Republic
T-22 G, T-22 HB	Trichoderma harzianum strain KRL-AG2	THT Inc., USA
Trichodex, Trichopel	Trichoderma harzianum	Makhteshim Chemical Works Ltd., USA
Trichopel, Trichoject, Trichodowels, Trichoseal	Trichoderma harzianum and Trichoderma viride	Agrimm Technologies Ltd., New Zealand
Trichopel	Trichoderma harzianumand Trichoderma viride	Agrimm Technologies Ltd., New Zealand
Trichoderma 2000	Trichoderma sp.	Myocontrol Ltd., Israel
Tri-control	Trichoderma spp.	Jeypee Biotechs, India
Trieco	Trichoderma viride	Ecosense Labs Pvt. Ltd., Mumbai, India
TY	Trichoderma sp.	Mycocontrol, Israel

References

1. Hawksworth, D.L.; Kirk, P.M.; Sutton, B.C.; Pegler, D.N. (1995). Ainsworth & Bisby's Dictionary of the Fungi. Wallingford, UK: CAB International.
2. Barnett, H.L. (1963). "The nature of mycoparasitism by fungi". Annu. Rev. Microbiol. 17: 1–14. doi:10.1146/annurev.mi.17.100163.000245.
3. Boosalis, M G (1964). "Hyperparasitism". Annual Review of Phytopathology. 2 (1): 363–376. doi:10.1146/annurev.py.02.090164.002051. ISSN 0066-4286.
4. JEFFRIES, PETER (1985). "Mycoparasitism within the Zygomycetes". Botanical Journal of the Linnean Society. 91 (1–2): 135–150. doi:10.1111/j.1095-8339.1985.tb01140.x. ISSN 0024-4074.
5. Ashraf, Shabbir; Zuhaib, Mohammad (2013), "Fungal Biodiversity: A Potential Tool in Plant Disease Management", Management of Microbial Resources in the Environment, Springer Netherlands, pp. 69–90, doi:10.1007/978-94-007-5931-2_4, ISBN 9789400759305
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8. Chet, I.; Harman, G. E.; Baker, R. (1981). "Trichoderma hamatum: Its hyphal interactions withRhizoctonia solani andPythium spp". Microbial Ecology. 7 (1): 29–38. doi:10.1007/bf02010476. ISSN 0095-3628. PMID 24227317.
9. Barak, R.; Elad, Y.; Mirelman, D.; Chet, I. (1985). "Lectins: a possible basis for specific recognition in the interaction of Trichoderma and Sclerotium rolfsii". Phytopathology. 75 (4): 458–462. doi:10.1094/phyto-75-458.
10. Druzhinina, Irina S.; Seidl-Seiboth, Verena; Herrera-Estrella, Alfredo; Horwitz, Benjamin A.; Kenerley, Charles M.; Monte, Enrique; Mukherjee, Prasun K.; Zeilinger, Susanne; Grigoriev, Igor V. (2011-09-16). "Trichoderma: the genomics of opportunistic success" (PDF). Nature Reviews Microbiology. 9 (10): 749–759. doi:10.1038/nrmicro2637. ISSN 1740-1526. PMID 21921934.
11. Karlsson, Magnus; Durling, Mikael Brandström; Choi, Jaeyoung; Kosawang, Chatchai; Lackner, Gerald; Tzelepis, Georgios D.; Nygren, Kristiina; Dubey, Mukesh K.; Kamou, Nathalie (2015-01-08). "Insights on the Evolution of Mycoparasitism from the Genome of Clonostachys rosea". Genome Biology and Evolution. 7 (2): 465–480. doi:10.1093/gbe/evu292. ISSN 1759-6653. PMC 4350171. PMID 25575496. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
12. Inbar, Jacob; Menendez, Ana; Chet, Ilan (1996). "Hyphal interaction between Trichoderma harzianum and Sclerotinia sclerotiorum and its role in biological control". Soil Biology and Biochemistry. 28 (6): 757–763. doi:10.1016/0038-0717(96)00010-7. ISSN 0038-0717.
13. Zeilinger, Susanne; Brunner, Kurt; Peterbauer, Clemens K.; Mach, Robert L.; Kubicek, Christian P.; Lorito, Matteo (2003-07-01). "The Nag1 N-acetylglucosaminidase of Trichoderma atroviride is essential for chitinase induction by chitin and of major relevance to biocontrol". Current Genetics. 43 (4): 289–295. doi:10.1007/s00294-003-0399-y. ISSN 0172-8083. PMID 12748812.
14. Troian, Rogério Fraga; Steindorff, Andrei Stecca; Ramada, Marcelo Henrique Soller; Arruda, Walquiria; Ulhoa, Cirano José (2014-06-26). "Mycoparasitism studies of Trichoderma harzianum against Sclerotinia sclerotiorum: evaluation of antagonism and expression of cell wall-degrading enzymes genes". Biotechnology Letters. 36 (10): 2095–2101. doi:10.1007/s10529-014-1583-5. ISSN 0141-5492. PMID 24966041.
15. Goh, Yit Kheng; Vujanovic, Vladimir (2010). "Biotrophic mycoparasitic interactions betweenSphaerodes mycoparasiticaand phytopathogenicFusariumspecies". Biocontrol Science and Technology. 20 (9): 891–902. doi:10.1080/09583157.2010.489147. ISSN 0958-3157.
16. Karlsson, Magnus; Durling, Mikael Brandström; Choi, Jaeyoung; Kosawang, Chatchai; Lackner, Gerald; Tzelepis, Georgios D.; Nygren, Kristiina; Dubey, Mukesh K.; Kamou, Nathalie (2015-01-08). "Insights on the Evolution of Mycoparasitism from the Genome of Clonostachys rosea". Genome Biology and Evolution. 7 (2): 465–480. doi:10.1093/gbe/evu292. ISSN 1759-6653. PMC 4350171. PMID 25575496.
17. Malik, Abdul; Grohmann, Elisabeth; Alves, Madalena, eds. (2013). Management of Microbial Resources in the Environment. doi:10.1007/978-94-007-5931-2. ISBN 978-94-007-5930-5.
18. Howell, C. R. (2003). "Mechanisms Employed by Trichoderma Species in the Biological Control of Plant Diseases: The History and Evolution of Current Concepts". Plant Disease. 87 (1): 4–10. doi:10.1094/pdis.2003.87.1.4. ISSN 0191-2917. PMID 30812698.
19. Vinale, Francesco; Sivasithamparam, Krishnapillai; Ghisalberti, Emilio L.; Marra, Roberta; Woo, Sheridan L.; Lorito, Matteo (2008). "Trichoderma–plant–pathogen interactions". Soil Biology and Biochemistry. 40 (1): 1–10. doi:10.1016/j.soilbio.2007.07.002. ISSN 0038-0717.