S. Naeimi

Bio: S. Naeimi is an academic researcher from University of Tehran. The author has contributed to research in topics: Trichoderma & Rhizoctonia solani. The author has an hindex of 8, co-authored 21 publications receiving 260 citations. Previous affiliations of S. Naeimi include Kangwon National University.

Biodiversity of the Genus Hypocrea/Trichoderma in Different Habitats

Abstract: This chapter attempts to summarize the recently available and rapidly increasing amount of information in the literature about the occurrence and biodiversity of Trichoderma species in different ecological habitats. Members of the genus are common in soil and rhizosphere of plants in natural and agricultural fields and forests and on decaying wood. They are also occurring in the air, settled dust and different water-related habitats including marine environments and drinking water. Furthermore, certain species are known as endophytes of plants, colonizers of mushroom-related natural and artificial substrata and facultative pathogens of humans, demonstrating a high adaptability to various ecological niches.

Biological Control of Rhizoctonia solani AG1-1A, the Causal Agent of Rice Sheath Blight with Trichoderma Strains

Abstract: Sheath blight caused by Rhizoctonia solani is one of the most serious rice diseases worldwide. The disease is currently managed only by the excessive application of chemical fungicides which are toxic and not environmentally friendly. Therefore, greater emphasis should be given to biological control as being both safe and effective. Trichoderma species are ubiquitous fungi in the soil and have an antagonistic activity against several soil-borne plant pathogens including R. solani . The present study was undertaken to evaluate the potential of indigenous Trichoderma strains from Mazandaran province, Northern Iran (a Mediterranean region on the southern coast of the Caspian Sea) against R. solani AG1-IA in vitro, and against sheath blight disease in the glasshouse, in order to find biocontrol isolates for application in the field. More than 200 Trichoderma strains were isolated from the soil, plant debris and the phyllosphere in rice felds. Strains were first screened for their antagonism to R. solani by in vitro antagonism tests including dual culture, antibiosis, the effect of Trichoderma strains on the production and viability of R. solani sclerotia, and hyperparasitism on microscopic slides. According to the in vitro experiments, several strains belonging to T. harzianum , T. virens and T. atroviride showed excellent biocontrol. These potential antagonist strains were further evaluated for their effectiveness in controlling sheath blight under glasshouse conditions. Among the 55 selected strains, seven significantly controlled the disease. T. harzianum AS12-2 was the most effective strain in controlling rice sheath blight, better even than propiconazole, the most commonly used fungicide in Iran.

A challenge to mushroom growers: the green mould disease of cultivated champignons

Abstract: The aim of this minireview is to give an overview of the literature about the green mould disease of cultivated champignons (Agaricus bisporus) caused by Trichoderma species. The first significant green mould epidemic appeared in Northern Ireland in 1985, which was quickly followed by subsequent outbreaks in several countries. The symptoms of green mould appear as large patches of compost turning green rapidly. Epidemic outbreaks are due to two varieties of the species T. aggressivum. This species competes efficiently for space and nutrients, produces extracellular enzymes, toxic secondary metabolites and volatile organic compounds, which results in drastical crop losses. The natural habitat of T. aggressivum is still unknown. Possible routes of infection include the air, vehicles, contaminated clothes and animal vectors. A primer pair for the specific identification of T. aggressivum is available for the fast and cheap monitoring of the causal agent. Possible management strategies include the application of disinfectants, pasteurization, adjustment of casing pH, chemical treatments, biological control by antagonistic bacteria as well as the cultivation of resistant Agaricus varieties.

Screening of Organic Substrates for Solid-State Fermentation, Viability and Bioefficacy of Trichoderma harzianum AS12-2, a Biocontrol Strain Against Rice Sheath Blight Disease

Abstract: The present study was undertaken to find the most suitable organic substrates for the biomass production, viability and efficacy of the biocontrol strain Trichoderma harzianum AS12-2 in the solid-state fermentation system. In total, 13 inexpensive, locally available substrates (agricultural wastes or by-products) were inoculated with the antagonist, and following one month of incubation at room temperature, all colonized substrates were air dried and ground to powder. The shelf life and viability of the Trichoderma strain were assessed as colony-forming units per gram (CFUs g−1) of each substrate on a monthly basis for up to one year at room temperature (25 ± 2 °C) and in the refrigerator (4 °C). In order to find out the effect of the substrate on the bioefficacy of T. harzianum AS12-2, the biocontrol potential of the formulations was evaluated against rice sheath blight disease caused by Rhizoctonia solani. The results showed that the fungus colonized more or less all substrates after one month, although the degree of colonization and conidiation was different among the substrates, being especially high in broom sorghum grain, rice husk, rice straw, rice bran and sugar beet pulp. Analysis of variance (ANOVA) of the population in the substrates in “Month 0” showed that the effect of treatment was significant, and the means were significantly different. The maximum population was recorded for broom sorghum grain and rice straw (6.4 × 1010 and 5.3 × 1010 CFUs g−1, respectively). The population declined in all substrates after one year of incubation at room temperature. This decline was relatively smaller in broom sorghum grain, rice straw and rice husk. On the other hand, the population in the same substrate incubated in the refrigerator was decreased in a mild slope, and the final population was high. In addition, the results of greenhouse assay showed that all bioformulations were effective in controlling the disease, and there were no significant differences among the substrates. According to the results of this study, broom sorghum grain, rice husk, rice straw, sugar beet pulp and cow dung could be recommended as suitable fermentation media for the industrial-scale production of T. harzianum strains.

The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species

Abstract: The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.

Environmental and Microbial Relationships

Abstract: Life History and Genetic Strategies 1 Evolutionary ecology of the first fungi J.H. Andrews and R.F. Harris 2 Molecular approaches for studying fungi in the environment K. Brunner, S. Zeilinger and R.L. Mach Determinants of Fungal Communities 3 Disturbances in natural ecosystems: scaling from fungal diversity to ecosystem functioning S.J. Morris, C.F. Friese, and M.F. Allen 4 Fungal Responses to Disturbance: agriculture and forestry R.M. Miller and D.J. Lodge 5 Fungi and industrial pollutants G.M. Gadd 6 Fungi in extreme environments N. Magan 7 Biogeography and conservation E.J.M. Arnolds Fungal Interactions and Biological Control Strategies 8 Mycoparasitism and antagonism A. Viterbo, J. Inbar, Y. Hadar and I. Chet 9 Antagonism of plant parasitic nematodes by fungi S. Casas-Flores and A. Herrera-Estrella 10 Entomopathogenic Fungi and their role in Pest Control A.K. Charnley and S. A. Collins 11 Bacterial weapons of fungal destruction: Phyllosphere targeted biological control of plant pathogens W. G. Dilantha Fernando, R. Ramarathnam and T. de Kievit 12 Effects of animals grazing on fungi. T. McGonigle 13 Endophytic Fungi P. Bayman 14 Mycorrhizal fungi: their habitats and nutritional strategies M. Girlanda, S. Perotto and P. Bonfante 15 Applications of fungal ecology in the search for new bioactive fungal products J.B. Gloer Decomposition, Biomass and Industrial Applications 16 Nutrient cycling by saprophytic fungi interrestrial habitats J. Dighton 17 Decomposition of plant litter by fungi in marine and freshwater ecosystems M.O. Gessner, V. Gulis, K. Kuehn, E. Chauvet and K. Suberkropp 18 Degradation of cellulose and hemicellulose polymers by fungi C. Gamauf, B. Metz and B. Seiboth

Trichoderma spp. – application and prospects for use in organic farming and industry

Abstract: Fungi of the genus Trichoderma are a very large group of microorganisms that play a significant role in the environment. They use a variety of mechanisms to colonise various ecological niches. Several Trichoderma spp. positively affect plants by stimulating plant growth, and protecting plants from fungal and bacterial pathogens. They are used in biological plant protection as biofungi- cides as well as in bioremediation. Members of the genus Trichoderma are also utilised in various industry branches - mainly in the production of enzymes, antibiotics, and other metabolites, but also of biofuel. Moreover, the genus Trichoderma comprises edible and medicinal mushrooms, but also the pathogens of humans. Currently, Trichoderma has entered the genomic era and parts of genome se- quences are publicly available. This is why, Trichoderma fungi have the potential to be used for human needs to an even greater extent than before. Nevertheless, further studies are needed to increase the efficiency and safety of the application of these fungi.