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Liu C, Jiang X, Tan Z, Wang R, Shang Q, Li H, Xu S, Aranda MA, Wu B. An Outstandingly Rare Occurrence of Mycoviruses in Soil Strains of the Plant-Beneficial Fungi from the Genus Trichoderma and a Novel Polymycoviridae Isolate. Microbiol Spectr 2023; 11:e0522822. [PMID: 37022156 PMCID: PMC10269472 DOI: 10.1128/spectrum.05228-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 01/31/2023] [Indexed: 04/07/2023] Open
Abstract
In fungi, viral infections frequently remain cryptic causing little or no phenotypic changes. It can indicate either a long history of coevolution or a strong immune system of the host. Some fungi are outstandingly ubiquitous and can be recovered from a great diversity of habitats. However, the role of viral infection in the emergence of environmental opportunistic species is not known. The genus of filamentous and mycoparasitic fungi Trichoderma (Hypocreales, Ascomycota) consists of more than 400 species, which mainly occur on dead wood, other fungi, or as endo- and epiphytes. However, some species are environmental opportunists because they are cosmopolitan, can establish in a diversity of habitats, and can also become pests on mushroom farms and infect immunocompromised humans. In this study, we investigated the library of 163 Trichoderma strains isolated from grassland soils in Inner Mongolia, China, and found only four strains with signs of the mycoviral nucleic acids, including a strain of T. barbatum infected with a novel strain of the Polymycoviridae and named and characterized here as Trichoderma barbatum polymycovirus 1 (TbPMV1). Phylogenetic analysis suggested that TbPMV1 was evolutionarily distinct from the Polymycoviridae isolated either from Eurotialean fungi or from the order Magnaportales. Although the Polymycoviridae viruses were also known from Hypocrealean Beauveria bassiana, the phylogeny of TbPMV1 did not reflect the phylogeny of the host. Our analysis lays the groundwork for further in-depth characterization of TbPMV1 and the role of mycoviruses in the emergence of environmental opportunism in Trichoderma. IMPORTANCE Although viruses infect all organisms, our knowledge of some groups of eukaryotes remains limited. For instance, the diversity of viruses infecting fungi-mycoviruses-is largely unknown. However, the knowledge of viruses associated with industrially relevant and plant-beneficial fungi, such as Trichoderma spp. (Hypocreales, Ascomycota), may shed light on the stability of their phenotypes and the expression of beneficial traits. In this study, we screened the library of soilborne Trichoderma strains because these isolates may be developed into bioeffectors for plant protection and sustainable agriculture. Notably, the diversity of endophytic viruses in soil Trichoderma was outstandingly low. Only 2% of 163 strains contained traces of dsRNA viruses, including the new Trichoderma barbatum polymycovirus 1 (TbPMV1) characterized in this study. TbPMV1 is the first mycovirus found in Trichoderma. Our results indicate that the limited data prevent the in-depth study of the evolutionary relationship between soilborne fungi and is worth further investigation.
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Affiliation(s)
- Chenchen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiliang Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhaoyan Tan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Rongqun Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Qiaoxia Shang
- Key Laboratory for Northern Urban Agriculture of Ministry of Agriculture and Rural Affairs, Beijing University of Agriculture, Beijing, China
| | - Hongrui Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Horticulture and Landscapes, Tianjin Agricultural University, Tianjin, China
| | - Shujin Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Horticulture and Landscapes, Tianjin Agricultural University, Tianjin, China
| | - Miguel A. Aranda
- Department of Stress Biology and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CEBAS)-CSIC, Murcia, Spain
| | - Beilei Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Variation in Tocochromanols Level and Mycotoxins Content in Sweet Maize Cultivars after Inoculation with Fusarium verticillioides and F. proliferatum. Foods 2022; 11:foods11182781. [PMID: 36140909 PMCID: PMC9497480 DOI: 10.3390/foods11182781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/18/2022] Open
Abstract
A major problem in maize production is the contamination of the grain with Fusarium spp., mainly F. proliferatum and F. verticillioides and their secondary metabolites—mycotoxins. Under biotic stress conditions, caused by a fungal pathogen, plants initiate a series of defense mechanisms that may cause quantitative and qualitative changes in the composition of phenolic compounds. We analyzed the resistance of four sweet maize cultivars (Syngenta Group: Overland, Sweetstar, GSS 8529, Shinerock) to the infection with Fusarium verticillioides and F. proliferatum isolates, along with fumonisins B1, B2, and B3 grain contamination and the levels of tocopherols and tocotrienols accumulated. Differences in ear rot levels were found between the cultivars and isolates used. The phenotypic evaluation positively correlated with the concentrations of fumonisins. The results obtained also indicate a significant dependence on tocochromanols content in sweet maize cultivars tested on the infection of plants with Fusarium isolates and fumonisin biosynthesis. Further studies are needed to investigate the mechanisms of the plant reaction and the effect of different levels of tocopherols and tocotrienols on Fusarium resistance and grain contamination with mycotoxins.
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Witaszak N, Lalak-Kańczugowska J, Waśkiewicz A, Stępień Ł. The Impacts of Asparagus Extract Fractions on Growth and Fumonisins Biosynthesis in Fusarium Proliferatum. Toxins (Basel) 2020; 12:toxins12020095. [PMID: 32019224 PMCID: PMC7077031 DOI: 10.3390/toxins12020095] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/19/2020] [Accepted: 01/28/2020] [Indexed: 12/20/2022] Open
Abstract
Asparagus is a genus consisting of over two hundred species of perennial plants. Fusarium proliferatum is a major asparagus pathogen and it biosynthesizes a variety of mycotoxins, of which fumonisins B are prevalent. Our previous studies on F. proliferatum strains indicated that asparagus extract affects the expression of FUM1 gene, encoding polyketide synthase, a key enzyme of the FUM gene cluster governing the biosynthesis of fumonisins. An asparagus-derived F. proliferatum strain increased fumonisin B1 production after extract fractions’ addition, reaching the maximum 2 or 24 h after treatment. The cultures yielded between 40 and 520 mg of dry weight of mycelia after 14 days of cultivation. The differences in fungal biomass amounts between the whole extract and its fractions may result from synergistic effect of all bioactive compounds present in asparagus extract. Among extract fractions, the methanolic fraction had the highest effect on the dry weight of the mycelium reaching about a 13-fold increase compared to the control. Furthermore, we measured the relative expression of the FUM1 gene. Due to the possible antifungal activity of tested extract fractions, future research will be focused on the identification of the Asparagus officinalis L. compounds responsible for this activity.
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Affiliation(s)
- Natalia Witaszak
- Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (N.W.); (Ł.S.)
| | - Justyna Lalak-Kańczugowska
- Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (N.W.); (Ł.S.)
- Correspondence:
| | - Agnieszka Waśkiewicz
- Department of Chemistry, Poznan University of Life Sciences, Wojska Polskiego 75, 60-637 Poznań, Poland;
| | - Łukasz Stępień
- Department of Pathogen Genetics and Plant Resistance, Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland; (N.W.); (Ł.S.)
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