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A virus-free (VF) A. fumigatus isolate has been shown to be resistant in competition with Pseudomonas as compared to the isogenic line infected with Aspergillus fumigatus polymycovirus 1 (AfuPmV-1), and this phenotype was apparently related to alterations in iron metabolism. Here we investigated further the mechanisms underpinning this phenotype. The extracellular siderophore profiles of five isogenic VF and virus-infected (VI) strains were sampled at 24, 31, 48, 54, and 72 h in submerged cultures and quantitatively examined by liquid chromatography and mass spectrometry. Intracellular profiles of conidia and cultures at the stationary growth phase were defined. VF A. fumigatus demonstrated the best fitness represented by the fastest onset of its exponential growth when grown on an iron-limited mineral medium. The exponential phase and transitional production phase of the extracellular triacetylfusarinine C (TafC) were achieved at 24 and 31 h, respectively, contrary to VI strains, which acted more slowly. As a result, the TafC reservoir was consumed sooner in the VF strain. Additionally, the VF strain had lower ferricrocin and higher hydroxyferricrocin content in the pellet during the stationary phase. All of these differences were significant (Kruskal–Wallis, p< 0.01). In our study, the siderophore reservoir of a VF strain was consumed sooner, improving the fitness of the VF strain in competition with P. aeruginosa.
Rutuja Patil; Ioly Kotta-Loizou; Andrea Palyzová; Tomáš Pluháček; Robert Coutts; David Stevens; Vladimír Havlíček. Freeing Aspergillus fumigatus of Polymycovirus Infection Renders It More Resistant to Competition with Pseudomonas aeruginosa Due to Altered Iron-Acquiring Tactics. Journal of Fungi 2021, 7, 497 .
AMA StyleRutuja Patil, Ioly Kotta-Loizou, Andrea Palyzová, Tomáš Pluháček, Robert Coutts, David Stevens, Vladimír Havlíček. Freeing Aspergillus fumigatus of Polymycovirus Infection Renders It More Resistant to Competition with Pseudomonas aeruginosa Due to Altered Iron-Acquiring Tactics. Journal of Fungi. 2021; 7 (7):497.
Chicago/Turabian StyleRutuja Patil; Ioly Kotta-Loizou; Andrea Palyzová; Tomáš Pluháček; Robert Coutts; David Stevens; Vladimír Havlíček. 2021. "Freeing Aspergillus fumigatus of Polymycovirus Infection Renders It More Resistant to Competition with Pseudomonas aeruginosa Due to Altered Iron-Acquiring Tactics." Journal of Fungi 7, no. 7: 497.
Nowadays, the focus of mycovirology research has expanded from plant pathogenic fungi and mycovirus mediated hypovirulence to include insect and human pathogenic fungi together with a range of mycovirus mediated phenotypes, such as hypervirulence, control of endophytic traits, regulation of metabolite production and drug resistance. In fungus–mycovirus–environmental interactions, the environment and both abiotic and biotic factors play crucial roles in whether and how mycovirus mediated phenotypes are manifest. Mycovirus infections result in alterations in the host transcriptome profile, via protein–protein interactions and triggering of antiviral RNA silencing in the fungus. These alterations, in combination with the environmental factors, may result in desirable phenotypic traits for the host, for us and in some cases for both.
Ioly Kotta-Loizou. Mycoviruses and their role in fungal pathogenesis. Current Opinion in Microbiology 2021, 63, 10 -18.
AMA StyleIoly Kotta-Loizou. Mycoviruses and their role in fungal pathogenesis. Current Opinion in Microbiology. 2021; 63 ():10-18.
Chicago/Turabian StyleIoly Kotta-Loizou. 2021. "Mycoviruses and their role in fungal pathogenesis." Current Opinion in Microbiology 63, no. : 10-18.
Aspergillus and Pseudomonas compete in nature, and are the commonest bacterial and fungal pathogens in some clinical settings, such as the cystic fibrosis lung. Virus infections of fungi occur naturally. Effects on fungal physiology need delineation. A common reference Aspergillus fumigatus strain, long studied in two (of many) laboratories, was found infected with the AfuPmV-1 virus. One isolate was cured of virus, producing a virus-free strain. Virus from the infected strain was purified and used to re-infect three subcultures of the virus-free fungus, producing six fungal strains, otherwise isogenic. They were studied in intermicrobial competition with Pseudomonas aeruginosa. Pseudomonas culture filtrates inhibited forming or preformed Aspergillus biofilm from infected strains to a greater extent, also seen when Pseudomonas volatiles were assayed on Aspergillus. Purified iron-chelating Pseudomonas molecules, known inhibitors of Aspergillus biofilm, reproduced these differences. Iron, a stimulus of Aspergillus, enhanced the virus-free fungus, compared to infected. All infected fungal strains behaved similarly in assays. We show an important consequence of virus infection, a weakening in intermicrobial competition. Viral infection may affect the outcome of bacterial–fungal competition in nature and patients. We suggest that this occurs via alteration in fungal stress responses, the mechanism best delineated here is a result of virus-induced altered Aspergillus iron metabolism.
Hasan Nazik; Ioly Kotta-Loizou; Gabriele Sass; Robert Coutts; David Stevens. Virus Infection of Aspergillus fumigatus Compromises the Fungus in Intermicrobial Competition. Viruses 2021, 13, 686 .
AMA StyleHasan Nazik, Ioly Kotta-Loizou, Gabriele Sass, Robert Coutts, David Stevens. Virus Infection of Aspergillus fumigatus Compromises the Fungus in Intermicrobial Competition. Viruses. 2021; 13 (4):686.
Chicago/Turabian StyleHasan Nazik; Ioly Kotta-Loizou; Gabriele Sass; Robert Coutts; David Stevens. 2021. "Virus Infection of Aspergillus fumigatus Compromises the Fungus in Intermicrobial Competition." Viruses 13, no. 4: 686.
Fungi are generally thought to live in host plants with a single lifestyle, being parasitism, commensalism, or mutualism. The former, known as phytopathogenic fungi, cause various plant diseases that result in significant losses every year; while the latter, such as endophytic fungi, can confer fitness to the host plants. It is unclear whether biological factors can modulate the parasitic and mutualistic traits of a fungus. In this study, we isolated and characterized a mycovirus from an endophytic strain of the fungus Pestalotiopsis theae, a pathogen of tea (Camellia sinensis). Based on molecular analysis, we tentatively designated the mycovirus as Pestalotiopsis theae chrysovirus-1 (PtCV1), a novel member of the family Chrysoviridae, genus Alphachrysovirus. PtCV1 has four double-stranded (ds) RNAs as its genome, ranging from 0.9 to 3.4 kbp in size, encapsidated in isometric particles. PtCV1 significantly reduced the growth rates of its host fungus in vitro (ANOVA; P-value < 0.001) and abolished its virulence in planta (ANOVA; P-value < 0.001), converting its host fungus to a non-pathogenic endophyte on tea leaves, while PtCV1-free isolates were highly virulent. Moreover, the presence of PtCV1 conferred high resistance to the host plants against the virulent P. theae strains. Here we report a mycovirus that modulates endophytic and phytopathogenic fungal traits and provides an alternative approach to biological control of plant diseases caused by fungi.
Lingling Zhou; Xuepei Li; Ioly Kotta-Loizou; Kaili Dong; Shifang Li; Dejiang Ni; Ni Hong; Guoping Wang; Wenxing Xu. A mycovirus modulates the endophytic and pathogenic traits of a plant associated fungus. The ISME Journal 2021, 1 -14.
AMA StyleLingling Zhou, Xuepei Li, Ioly Kotta-Loizou, Kaili Dong, Shifang Li, Dejiang Ni, Ni Hong, Guoping Wang, Wenxing Xu. A mycovirus modulates the endophytic and pathogenic traits of a plant associated fungus. The ISME Journal. 2021; ():1-14.
Chicago/Turabian StyleLingling Zhou; Xuepei Li; Ioly Kotta-Loizou; Kaili Dong; Shifang Li; Dejiang Ni; Ni Hong; Guoping Wang; Wenxing Xu. 2021. "A mycovirus modulates the endophytic and pathogenic traits of a plant associated fungus." The ISME Journal , no. : 1-14.
Polymycoviridae is a growing family of mycoviruses whose members typically have non-conventional capsids and multi-segmented, double-stranded (ds) RNA genomes. Beauveria bassiana polymycovirus (BbPmV) 1 is known to enhance the growth and virulence of its fungal host, the entomopathogenic ascomycete and popular biological control agent B. bassiana. Here we report the complete sequence of BbPmV-3, which has six genomic dsRNA segments. Phylogenetic analysis of RNA-dependent RNA polymerase (RdRp) protein sequences revealed that BbPmV-3 is closely related to the partially sequenced BbPmV-2 but not BbPmV-1. Nevertheless, both BbPmV-3 and BbPmV-1 have similar effects on their respective host isolates ATHUM 4946 and EABb 92/11-Dm, affecting pigmentation, sporulation, and radial growth. Production of conidia and radial growth are significantly enhanced in virus-infected isolates as compared to virus-free isogenic lines on Czapek-Dox complete and minimal media that contain sucrose and sodium nitrate. However, this polymycovirus-mediated effect on growth is dependent on the carbon and nitrogen sources available to the host fungus. Both BbPmV-3 and BbPmV-1 increase growth of ATHUM 4946 and EABb 92/11-Dm when sucrose is replaced by lactose, trehalose, glucose, or glycerol, while the effect is reversed on maltose and fructose. Similarly, both BbPmV-3 and BbPmV-1 decrease growth of ATHUM 4946 and EABb 92/11-Dm when sodium nitrate is replaced by sodium nitrite, potassium nitrate, or ammonium nitrate. In conclusion, the effects of polymycoviruses on B. bassiana are at least partially mediated via its metabolic pathways.
Charalampos Filippou; Rebecca M. Diss; John O. Daudu; Robert H. A. Coutts; Ioly Kotta-Loizou. The Polymycovirus-Mediated Growth Enhancement of the Entomopathogenic Fungus Beauveria bassiana Is Dependent on Carbon and Nitrogen Metabolism. Frontiers in Microbiology 2021, 12, 1 .
AMA StyleCharalampos Filippou, Rebecca M. Diss, John O. Daudu, Robert H. A. Coutts, Ioly Kotta-Loizou. The Polymycovirus-Mediated Growth Enhancement of the Entomopathogenic Fungus Beauveria bassiana Is Dependent on Carbon and Nitrogen Metabolism. Frontiers in Microbiology. 2021; 12 ():1.
Chicago/Turabian StyleCharalampos Filippou; Rebecca M. Diss; John O. Daudu; Robert H. A. Coutts; Ioly Kotta-Loizou. 2021. "The Polymycovirus-Mediated Growth Enhancement of the Entomopathogenic Fungus Beauveria bassiana Is Dependent on Carbon and Nitrogen Metabolism." Frontiers in Microbiology 12, no. : 1.
Oxidative stress occurs as a result of an imbalance in reactive oxygen species (ROS) and antioxidant defences within the cells. It plays a key role in many physiological disease states, ranging from Alzheimer’s to cancer, as well as in infectious diseases; for instance, oxidative stress is significant during bacterial infection where macrophages and neutrophils subject pathogenic bacteria to oxidising environments or upon exposure to antibiotics. Therefore, it is vital to understand the systems biology of oxidative stress in order to effectively tackle the many issues that it is related to. In this chapter, computational approaches applied for understanding oxidative stress in bacteria and eukaryotes will be detailed together with the relevant biological advances. These approaches include construction of protein–protein interaction networks, logical and flux balance modelling techniques, machine learning applications and, lastly, high-throughput genomic methods such as next-generation sequencing, which generates data to be used in the aforementioned techniques. Finally, several case studies will be presented and discussed in the context of oxidative stress.
Harry Beaven; Ioly Kotta-Loizou. Modelling Oxidative Stress Pathways. Methods in Molecular Biology 2020, 277 -300.
AMA StyleHarry Beaven, Ioly Kotta-Loizou. Modelling Oxidative Stress Pathways. Methods in Molecular Biology. 2020; ():277-300.
Chicago/Turabian StyleHarry Beaven; Ioly Kotta-Loizou. 2020. "Modelling Oxidative Stress Pathways." Methods in Molecular Biology , no. : 277-300.
A Portuguese isolate of Aspergillus fumigatus was found to contain three double-stranded (ds) RNA elements ranging in size from 1.1 to 1.8 kbp and comprising the genome of a strain of Aspergillus fumigatus partitivirus 1 (AfuPV-1) previously thought to contain only the two largest dsRNA elements. The sequence of the smallest dsRNA element is described here, completing the sequence of the AfuPV-1 genome. Sequence analysis of the element revealed an open reading frame encoding a protein of unknown function similar in size and distantly related to elements previously identified in other members of the family Partitiviridae.
Charalampos Filippou; Robert H. A. Coutts; David A. Stevens; Raquel Sabino; Ioly Kotta-Loizou. Completion of the sequence of the Aspergillus fumigatus partitivirus 1 genome. Archives of Virology 2020, 165, 1891 -1894.
AMA StyleCharalampos Filippou, Robert H. A. Coutts, David A. Stevens, Raquel Sabino, Ioly Kotta-Loizou. Completion of the sequence of the Aspergillus fumigatus partitivirus 1 genome. Archives of Virology. 2020; 165 (8):1891-1894.
Chicago/Turabian StyleCharalampos Filippou; Robert H. A. Coutts; David A. Stevens; Raquel Sabino; Ioly Kotta-Loizou. 2020. "Completion of the sequence of the Aspergillus fumigatus partitivirus 1 genome." Archives of Virology 165, no. 8: 1891-1894.
Phenotypic heterogeneity in clonal bacterial batch cultures is an important adaptive strategy to changing environments, including in diazotrophs with the unique capacity to convert di-nitrogen into bio-available ammonium. In diazotrophicKlebsiella oxytocawe simultaneously measured mRNA levels of key regulatory (glnK-amtB, nifLA) and structural (nifHDK) operons required for establishing nitrogen fixation, using dual molecule, single cell RNA-FISH. Through stochastic transcription models and mutual information analysis we revealed likely molecular origins for heterogeneity in nitrogenase expression. In wildtype and regulatory variant strains we inferred contributions from intrinsic and extrinsic noise, finding thatnifHDKtranscription is inherently bursty, but that noise propagation through signalling is also significant. The regulatory geneglnKhad the highest discernible effect onnifHDKvariance, while noise from factors outside of the regulatory pathway were negligible. Results provide evidence that heterogeneity is a fundamental property of this regulatory system, indicating potential constraints for engineering homogeneous nitrogenase expression.
Tufail Bashir; Rowan D Brackston; Christopher J. Waite; Ioly Kotta-Loizou; Christoph Engl; Martin Buck; Jörg Schumacher. Molecular origins of transcriptional heterogeneity in diazotrophicK. oxytoca. 2020, 1 .
AMA StyleTufail Bashir, Rowan D Brackston, Christopher J. Waite, Ioly Kotta-Loizou, Christoph Engl, Martin Buck, Jörg Schumacher. Molecular origins of transcriptional heterogeneity in diazotrophicK. oxytoca. . 2020; ():1.
Chicago/Turabian StyleTufail Bashir; Rowan D Brackston; Christopher J. Waite; Ioly Kotta-Loizou; Christoph Engl; Martin Buck; Jörg Schumacher. 2020. "Molecular origins of transcriptional heterogeneity in diazotrophicK. oxytoca." , no. : 1.
Members of the family Chrysoviridae are isometric, non-enveloped viruses with segmented, linear, dsRNA genomes. There are 3–7 genomic segments, each of which is individually encapsidated. Chrysoviruses infect fungi, plants and possibly insects, and may cause hypovirulence in their fungal hosts. Chrysoviruses have no known vectors and lack an extracellular phase to their replication cycle; they are transmitted via intracellular routes within an individual during hyphal growth, in asexual or sexual spores, or between individuals via hyphal anastomosis. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the family Chrysoviridae, which is available at ictv.global/report/chrysoviridae.
Ioly Kotta-Loizou; Jose Caston; Robert H. A. Coutts; Bradley I. Hillman; Daohong Jiang; Dae-Hyuk Kim; Hiromitsu Moriyama; Nobuhiro Suzuki; ICTV Report Consortium. ICTV Virus Taxonomy Profile: Chrysoviridae. Journal of General Virology 2020, 101, 143 -144.
AMA StyleIoly Kotta-Loizou, Jose Caston, Robert H. A. Coutts, Bradley I. Hillman, Daohong Jiang, Dae-Hyuk Kim, Hiromitsu Moriyama, Nobuhiro Suzuki, ICTV Report Consortium. ICTV Virus Taxonomy Profile: Chrysoviridae. Journal of General Virology. 2020; 101 (2):143-144.
Chicago/Turabian StyleIoly Kotta-Loizou; Jose Caston; Robert H. A. Coutts; Bradley I. Hillman; Daohong Jiang; Dae-Hyuk Kim; Hiromitsu Moriyama; Nobuhiro Suzuki; ICTV Report Consortium. 2020. "ICTV Virus Taxonomy Profile: Chrysoviridae." Journal of General Virology 101, no. 2: 143-144.
The cosmopolitan insect-pathogenic fungus and popular biocontrol agent Beauveria bassiana can be used to control Anopheles mosquito populations and restrict the spread of malaria, the deadliest vector-borne infectious disease in the world caused by the protozoan parasite Plasmodium. Here, we establish that infection with a double-stranded (ds)RNA mycovirus, Beauveria bassiana polymycovirus (BbPmV)-1, significantly reduces B. bassiana virulence against A. coluzzii, the main vector of malaria. The BbPmV-1-mediated hypovirulence can be at least partially attributed to slow fungal growth on the mosquitos. Analysis of the dual next-generation sequencing of the B. bassiana and A. coluzzii transcriptomes provided insight into the molecular mechanisms of the BbPmV-1-mediated effects. BbPmV-1-free B. bassiana has a wide impact on the A. coluzzii transcriptome, affecting immunity and metabolism, and led to the identification of novel immune response proteins. BbPmV-1 regulates the gene expression profile of its fungal host, directing the use of available resources towards sporulation and suppressing the mosquito immune system. Additionally, BbPmV-1-infected and -free B. bassiana strains differentially modulate mosquito gut microbiota; the former reduces the bacterial genus Elizabethkingia and the latter Serratia. Co-transfection of mosquitos with B. bassiana and P. berghei revealed a reduction of ookinetes in the presence of BbPmV-1, potentially due to the upregulation of a mycotoxin. Finally, BbPmV-1-mediated hypovirulence is at least partially dependent on the A. coluzzii RNAi pathway, and silencing of the dicer-2 gene restores virulence. Taken together, our data clearly demonstrate the crucial role of mycovirus infection in mediating B. bassiana virulence against A. coluzzii and suggest that BbPmV-1 protects A. coluzzii from B. bassiana, the mosquito’s own immune system, potentially harmful gut microbiota, and Plasmodium parasites.
Andre N. Pitaluga; Charalampos Filippou; Josephine Blakiston; Robert H.A. Coutts; George K. Christophides; Ioly Kotta-Loizou. A Mycovirus Mediates the Virulence of an Insect-Killing Fungus against the Malaria Mosquito Vector. Proceedings 2020, 50, 148 .
AMA StyleAndre N. Pitaluga, Charalampos Filippou, Josephine Blakiston, Robert H.A. Coutts, George K. Christophides, Ioly Kotta-Loizou. A Mycovirus Mediates the Virulence of an Insect-Killing Fungus against the Malaria Mosquito Vector. Proceedings. 2020; 50 (1):148.
Chicago/Turabian StyleAndre N. Pitaluga; Charalampos Filippou; Josephine Blakiston; Robert H.A. Coutts; George K. Christophides; Ioly Kotta-Loizou. 2020. "A Mycovirus Mediates the Virulence of an Insect-Killing Fungus against the Malaria Mosquito Vector." Proceedings 50, no. 1: 148.
Phoma stem canker (blackleg) is one of the most important diseases of winter oilseed rape (Brassica napus) worldwide and is caused by a complex that comprises at least two species: Leptosphaeria maculans and L. biglobosa. Screening a panel of field Leptosphaeria isolates from B. napus for the presence of mycoviruses revealed the presence of a novel double-stranded RNA quadrivirus in L. biglobosa and no viruses in L. maculans. Following elimination of the mycovirus, virus-infected and virus-free isogenic lines of L. biglobosa were created. A direct comparison of the growth and virulence of these isogenic lines illustrated that virus infection caused hypervirulence and resulted in induced systemic resistance toward L. maculans in B. napus following lower leaf preinoculation with the virus-infected isolate. Analysis of the plant transcriptome suggests that the presence of the virus leads to subtle alterations in metabolism and plant defenses. For instance, transcripts involved in carbohydrate and amino acid metabolism are enriched in plants treated with the virus-infected isolate, while pathogenesis-related proteins, chitinases and WRKY transcription factors are differentially expressed. These results illustrate the potential for deliberate inoculation of plants with hypervirulent L. biglobosa to decrease the severity of Phoma stem canker later in the growing season. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .
Unnati A. Shah; Ioly Kotta-Loizou; Bruce D. L. Fitt; Robert H. A. Coutts. Mycovirus-Induced Hypervirulence of Leptosphaeria biglobosa Enhances Systemic Acquired Resistance to Leptosphaeria maculans in Brassica napus. Molecular Plant-Microbe Interactions® 2020, 33, 98 -107.
AMA StyleUnnati A. Shah, Ioly Kotta-Loizou, Bruce D. L. Fitt, Robert H. A. Coutts. Mycovirus-Induced Hypervirulence of Leptosphaeria biglobosa Enhances Systemic Acquired Resistance to Leptosphaeria maculans in Brassica napus. Molecular Plant-Microbe Interactions®. 2020; 33 (1):98-107.
Chicago/Turabian StyleUnnati A. Shah; Ioly Kotta-Loizou; Bruce D. L. Fitt; Robert H. A. Coutts. 2020. "Mycovirus-Induced Hypervirulence of Leptosphaeria biglobosa Enhances Systemic Acquired Resistance to Leptosphaeria maculans in Brassica napus." Molecular Plant-Microbe Interactions® 33, no. 1: 98-107.
The cosmopolitan fungus Rhizoctonia solani has a wide host range and is the causal agent of numerous crop diseases, leading to significant economic losses. To date, no cultivars showing complete resistance to R. solani have been identified and it is imperative to develop a strategy to control the spread of the disease. Fungal viruses, or mycoviruses, are widespread in all major groups of fungi and next-generation sequencing (NGS) is currently the most efficient approach for their identification. An increasing number of novel mycoviruses are being reported, including double-stranded (ds) RNA, circular single-stranded (ss) DNA, negative sense (−)ssRNA, and positive sense (+)ssRNA viruses. The majority of mycovirus infections are cryptic with no obvious symptoms on the hosts; however, some mycoviruses may alter fungal host pathogenicity resulting in hypervirulence or hypovirulence and are therefore potential biological control agents that could be used to combat fungal diseases. R. solani harbors a range of dsRNA and ssRNA viruses, either belonging to established families, such as Endornaviridae, Tymoviridae, Partitiviridae, and Narnaviridae, or unclassified, and some of them have been associated with hypervirulence or hypovirulence. Here we discuss in depth the molecular features of known viruses infecting R. solani and their potential as biological control agents.
Assane Hamidou Abdoulaye; Mohamed Frahat Foda; Ioly Kotta-Loizou. Viruses Infecting the Plant Pathogenic Fungus Rhizoctonia solani. Viruses 2019, 11, 1113 .
AMA StyleAssane Hamidou Abdoulaye, Mohamed Frahat Foda, Ioly Kotta-Loizou. Viruses Infecting the Plant Pathogenic Fungus Rhizoctonia solani. Viruses. 2019; 11 (12):1113.
Chicago/Turabian StyleAssane Hamidou Abdoulaye; Mohamed Frahat Foda; Ioly Kotta-Loizou. 2019. "Viruses Infecting the Plant Pathogenic Fungus Rhizoctonia solani." Viruses 11, no. 12: 1113.
Banana trees, citrus fruit trees, pome fruit trees, grapevines, mango trees, and stone fruit trees are major fruit trees cultured worldwide and correspond to nearly 90% of the global production of woody fruit trees. In light of the above, the present manuscript summarizes the viruses that infect the major fruit trees, including their taxonomy and morphology, and highlights selected viruses that significantly affect fruit production, including their genomic and biological features. The results showed that a total of 163 viruses, belonging to 45 genera classified into 23 families have been reported to infect the major woody fruit trees. It is clear that there is higher accumulation of viruses in grapevine (80/163) compared to the other fruit trees (each corresponding to less than 35/163), while only one virus species has been reported infecting mango. Most of the viruses (over 70%) infecting woody fruit trees are positive-sense single-stranded RNA (+ssRNA), and the remainder belong to the -ssRNA, ssRNA-RT, dsRNA, ssDNA and dsDNA-RT groups (each corresponding to less than 8%). Most of the viruses are icosahedral or isometric (79/163), and their diameter ranges from 16 to 80 nm with the majority being 25–30 nm. Cross-infection has occurred in a high frequency among pome and stone fruit trees, whereas no or little cross-infection has occurred among banana, citrus and grapevine. The viruses infecting woody fruit trees are mostly transmitted by vegetative propagation, grafting, and root grafting in orchards and are usually vectored by mealybug, soft scale, aphids, mites or thrips. These viruses cause adverse effects in their fruit tree hosts, inducing a wide range of symptoms and significant damage, such as reduced yield, quality, vigor and longevity.
Muhammad Umer; Jiwen Liu; Huafeng You; Chuan Xu; Kaili Dong; Ni Luo; Linghong Kong; Xuepei Li; Ni Hong; Guoping Wang; Xudong Fan; Ioly Kotta-Loizou; Wenxing Xu. Genomic, Morphological and Biological Traits of the Viruses Infecting Major Fruit Trees. Viruses 2019, 11, 515 .
AMA StyleMuhammad Umer, Jiwen Liu, Huafeng You, Chuan Xu, Kaili Dong, Ni Luo, Linghong Kong, Xuepei Li, Ni Hong, Guoping Wang, Xudong Fan, Ioly Kotta-Loizou, Wenxing Xu. Genomic, Morphological and Biological Traits of the Viruses Infecting Major Fruit Trees. Viruses. 2019; 11 (6):515.
Chicago/Turabian StyleMuhammad Umer; Jiwen Liu; Huafeng You; Chuan Xu; Kaili Dong; Ni Luo; Linghong Kong; Xuepei Li; Ni Hong; Guoping Wang; Xudong Fan; Ioly Kotta-Loizou; Wenxing Xu. 2019. "Genomic, Morphological and Biological Traits of the Viruses Infecting Major Fruit Trees." Viruses 11, no. 6: 515.
Viruses preferentially encapsidate their own genomic RNA, sometimes as a result of the presence of clearly defined packaging signals (PSs) in their genome sequence. Recently, a novel form of short degenerate PSs has been proposed (N. Patel, E. C. Dykeman, R. H. A. Coutts, G. P. Lomonossoff, et al., Proc Natl Acad Sci U S A 112:2227–2232, 2015, https://doi.org/10.1073/pnas.1420812112 ; N. Patel, E. Wroblewski, G. Leonov, S. E. V. Phillips, et al., Proc Natl Acad Sci U S A 114:12255–12260, 2017, https://doi.org/10.1073/pnas.1706951114 ) using satellite tobacco necrosis virus 1 (STNV-1) as a model system for in vitro studies. It has been suggested that competing with these putative PSs may constitute a novel therapeutic approach against pathogenic single-stranded RNA viruses. Our work demonstrates that the previously identified PSs have no discernible significance for the selective packaging of STNV-1 in vivo in the presence and absence of competition or replication: viral sequences are encapsidated mostly on the basis of their abundance within the cell, while encapsidation of host RNAs also occurs. Nevertheless, the putative PSs identified in STNV-1 RNA may still have applications in bionanotechnology, such as the in vitro selective packaging of RNA molecules.
Ioly Kotta-Loizou; Hadrien Peyret; Keith Saunders; Robert H. A. Coutts; George P. Lomonossoff. Investigating the Biological Relevance of In Vitro -Identified Putative Packaging Signals at the 5′ Terminus of Satellite Tobacco Necrosis Virus 1 Genomic RNA. Journal of Virology 2019, 93, 1 .
AMA StyleIoly Kotta-Loizou, Hadrien Peyret, Keith Saunders, Robert H. A. Coutts, George P. Lomonossoff. Investigating the Biological Relevance of In Vitro -Identified Putative Packaging Signals at the 5′ Terminus of Satellite Tobacco Necrosis Virus 1 Genomic RNA. Journal of Virology. 2019; 93 (9):1.
Chicago/Turabian StyleIoly Kotta-Loizou; Hadrien Peyret; Keith Saunders; Robert H. A. Coutts; George P. Lomonossoff. 2019. "Investigating the Biological Relevance of In Vitro -Identified Putative Packaging Signals at the 5′ Terminus of Satellite Tobacco Necrosis Virus 1 Genomic RNA." Journal of Virology 93, no. 9: 1.
Approximately a year ago, when I accepted the offer to act as a Guest Editor for the Special Issue 'Mycoviruses' organised by the MDPI journal Viruses, I dared not expect that 'Mycoviruses' would include such a large number of manuscripts [...].
Ioly Kotta-Loizou; Kotta- Loizou. Mycoviruses: Past, Present, and Future. Viruses 2019, 11, 361 .
AMA StyleIoly Kotta-Loizou, Kotta- Loizou. Mycoviruses: Past, Present, and Future. Viruses. 2019; 11 (4):361.
Chicago/Turabian StyleIoly Kotta-Loizou; Kotta- Loizou. 2019. "Mycoviruses: Past, Present, and Future." Viruses 11, no. 4: 361.
Here we report the molecular characterisation of a novel dsRNA virus isolated from the filamentous, plant pathogenic fungus Leptosphaeria biglobosa and known to cause significant alterations to fungal pigmentation and growth and to result in hypervirulence, as illustrated by comparisons between virus-infected and -cured isogenic fungal strains. The virus forms isometric particles approximately 40–45 nm in diameter and has a quadripartite dsRNA genome structure with size ranges of 4.9 to 4 kbp, each possessing a single ORF. Sequence analysis of the putative proteins encoded by dsRNAs 1–4, termed P1–P4, respectively, revealed modest similarities to the amino acid sequences of equivalent proteins predicted from the nucleotide sequences of known and suspected members of the family Quadriviridae and for that reason the virus was nominated Leptosphaeria biglobosa quadrivirus-1 (LbQV-1). Sequence and phylogenetic analysis using the P3 sequence, which encodes an RdRP, revealed that LbQV-1 was most closely related to known and suspected quadriviruses and monopartite totiviruses rather than other quadripartite mycoviruses including chrysoviruses and alternaviruses. Of the remaining encoded proteins, LbQV-1 P2 and P4 are structural proteins but the function of P1 is unknown. We propose that LbQV-1 is a novel member of the family Quadriviridae.
Unnati A. Shah; Ioly Kotta-Loizou; Bruce D. L. Fitt; Robert H. A. Coutts. Identification, Molecular Characterization, and Biology of a Novel Quadrivirus Infecting the Phytopathogenic Fungus Leptosphaeria biglobosa. Viruses 2018, 11, 9 .
AMA StyleUnnati A. Shah, Ioly Kotta-Loizou, Bruce D. L. Fitt, Robert H. A. Coutts. Identification, Molecular Characterization, and Biology of a Novel Quadrivirus Infecting the Phytopathogenic Fungus Leptosphaeria biglobosa. Viruses. 2018; 11 (1):9.
Chicago/Turabian StyleUnnati A. Shah; Ioly Kotta-Loizou; Bruce D. L. Fitt; Robert H. A. Coutts. 2018. "Identification, Molecular Characterization, and Biology of a Novel Quadrivirus Infecting the Phytopathogenic Fungus Leptosphaeria biglobosa." Viruses 11, no. 1: 9.
The use of mycoviruses to manipulate the virulence of entomopathogenic fungi employed as biocontrol agents may lead to the development of novel methods to control attacks by insect pests. Such approaches are urgently required, as existing agrochemicals are being withdrawn from the market due to environmental and health concerns. The aim of this work is to investigate the presence and diversity of mycoviruses in large panels of entomopathogenic fungi, mostly from Spain and Denmark. In total, 151 isolates belonging to the genera Beauveria, Metarhizium, Lecanicillium, Purpureocillium, Isaria, and Paecilomyces were screened for the presence of dsRNA elements and 12 Spanish B. bassiana isolates were found to harbor mycoviruses. All identified mycoviruses belong to three previously characterised species, the officially recognised Beauveria bassiana victorivirus 1 (BbVV-1) and the proposed Beauveria bassiana partitivirus 2 (BbPV-2) and Beauveria bassiana polymycovirus 1 (BbPmV-1); individual B. bassiana isolates may harbor up to three of these mycoviruses. Notably, these mycovirus species are under distinct selection pressures, while recombination of viral genomes increases population diversity. Phylogenetic analysis of the RNA-dependent RNA polymerase gene sequences revealed that the current population structure in Spain is potentially a result of both vertical and horizontal mycovirus transmission. Finally, pathogenicity experiments using the Mediterranean fruit fly Ceratitis capitata showed no direct correlation between the presence of any particular mycovirus and the virulence of the B. bassiana isolates, but illustrated potentially interesting isolates that exhibit relatively high virulence, which will be used in more detailed virulence experimentation in the future.
Charalampos Filippou; Inmaculada Garrido-Jurado; Nicolai V. Meyling; Enrique Quesada-Moraga; Robert H. A. Coutts; Ioly Kotta-Loizou. Mycoviral Population Dynamics in Spanish Isolates of the Entomopathogenic Fungus Beauveria bassiana. Viruses 2018, 10, 665 .
AMA StyleCharalampos Filippou, Inmaculada Garrido-Jurado, Nicolai V. Meyling, Enrique Quesada-Moraga, Robert H. A. Coutts, Ioly Kotta-Loizou. Mycoviral Population Dynamics in Spanish Isolates of the Entomopathogenic Fungus Beauveria bassiana. Viruses. 2018; 10 (12):665.
Chicago/Turabian StyleCharalampos Filippou; Inmaculada Garrido-Jurado; Nicolai V. Meyling; Enrique Quesada-Moraga; Robert H. A. Coutts; Ioly Kotta-Loizou. 2018. "Mycoviral Population Dynamics in Spanish Isolates of the Entomopathogenic Fungus Beauveria bassiana." Viruses 10, no. 12: 665.
Background. Hu-antigen R (HuR) is a posttranscriptional regulator of several target mRNAs, implicated in carcinogenesis. This review aims to present the current evidence regarding the biological role and potential clinical significance of HuR in head and neck carcinomas. Methods. The existing literature concerning HuR expression and function in head and neck carcinomas is critically presented and summarised. Results. HuR is expressed in the majority of the examined samples, showing higher cytoplasmic levels in malignant or premalignant cases. Moreover, HuR modulates several genes implicated in biological processes important for malignant transformation, growth, and invasiveness. HuR seems to be an adverse prognosticator in patients with OSCCs, whereas a correlation with a more aggressive phenotype is reported in several types of carcinomas. Conclusions. A consistent role of HuR in the carcinogenesis and progression of head and neck carcinomas is suggested; nevertheless, further studies are warranted to expand the present information.
Georgia Levidou; Ioly Kotta-Loizou; Jason Tasoulas; Thomas Papadopoulos; Stamatios Theocharis. Clinical Significance and Biological Role of HuR in Head and Neck Carcinomas. Disease Markers 2018, 2018, 1 -13.
AMA StyleGeorgia Levidou, Ioly Kotta-Loizou, Jason Tasoulas, Thomas Papadopoulos, Stamatios Theocharis. Clinical Significance and Biological Role of HuR in Head and Neck Carcinomas. Disease Markers. 2018; 2018 ():1-13.
Chicago/Turabian StyleGeorgia Levidou; Ioly Kotta-Loizou; Jason Tasoulas; Thomas Papadopoulos; Stamatios Theocharis. 2018. "Clinical Significance and Biological Role of HuR in Head and Neck Carcinomas." Disease Markers 2018, no. : 1-13.
Fungi, similar to all species, are susceptible to viral infection. Aspergillus is arguably the most well studied fungal genus because of its medical, ecological and economical significance. Mycoviruses were initially detected in Aspergillus species almost 50 years ago and the field continues to be active today with ground-breaking discoveries. The aim of the present review is to cover the scientific progress in all aspects of mycovirology as exemplified by Aspergillus-focused research. Initially an overview of the population studies illustrating the presence of mycoviruses in numerous important Aspergillus species, such as A. niger, A. flavus and A. fumigatus with be presented. Moreover the intricacies of mycovirus transmission, both inter- and intra-species, will be discussed together with the methodologies used to investigate viral dispersion in a laboratory setting. Subsequently, the genomic features of all molecularly characterised mycoviruses to date will be analysed in depth. These include members of established viral families, such as Partitiviridae, Chrysoviridae and Totiviridae, but also more recent, novel discoveries that led to the proposal of new viral families, such as Polymycoviridae, Alternaviridae and, in the context of the present review, Exartaviridae. Finally, the major issue of phenotypic effects of mycoviral infection on the host is addressed, including aflatoxin production in A. flavus, together with growth and virulence in A. fumigatus. Although the molecular mechanisms behind these phenomena are yet to be elucidated, recent studies suggest that by implication, RNA silencing may be involved.
Ioly Kotta-Loizou; Robert H. A. Coutts. Mycoviruses in Aspergilli: A Comprehensive Review. Frontiers in Microbiology 2017, 8, 1699 .
AMA StyleIoly Kotta-Loizou, Robert H. A. Coutts. Mycoviruses in Aspergilli: A Comprehensive Review. Frontiers in Microbiology. 2017; 8 ():1699.
Chicago/Turabian StyleIoly Kotta-Loizou; Robert H. A. Coutts. 2017. "Mycoviruses in Aspergilli: A Comprehensive Review." Frontiers in Microbiology 8, no. : 1699.
Background/Aim: The focal adhesion kinase (FAK)/SRC phosphorylation cascade and its downstream target paxillin have been implicated in malignant transformation, tumor growth and progression, together with metastasis. The present study aimed to evaluate the clinical significance of concomitant FAK/SRC and p-paxillin expression in mobile tongue squamous cell carcinoma (SCC). Materials and Methods: FAK, SRC and phospho-paxillin expression in 48 mobile tongue SCC tissue samples was assessed immunohistochemically and analyzed with respect to clinicopathological characteristics and patient survival. Results: Concomitant high FAK/SRC expression was significantly associated with high grade of tumor differentiation (p=0.048) and longer disease-free patient survival (log-rank test, p=0.019). High p-paxillin expression was significantly associated with greater depth of invasion (p=0.002), lymph node metastasis (p=0.048) and poorer disease-free patient survival (log-rank test, p=0.021; Cox-regression analysis, p=0.031). Conclusion: The present study provides evidence that FAK/SRC and paxillin play a role in the pathophysiological aspects of mobile tongue SCC and could constitute therapeutic targets.
Stamatios Theocharis; Ioly Kotta-Loizou; Constantinos Giaginis; Paraskevi Alexandrou; Eugene Danas; Gerasimos Tsourouflis; Nikolaos Tsoukalas; Robert H.A. Coutts; Jason Tasoulas; Jerzy Klijanienko. Expression and Clinical Significance of Concomitant FAK/SRC and p-Paxillin in Mobile Tongue Squamous Cell Carcinoma. Anticancer Research 2017, 37, 1313 -1320.
AMA StyleStamatios Theocharis, Ioly Kotta-Loizou, Constantinos Giaginis, Paraskevi Alexandrou, Eugene Danas, Gerasimos Tsourouflis, Nikolaos Tsoukalas, Robert H.A. Coutts, Jason Tasoulas, Jerzy Klijanienko. Expression and Clinical Significance of Concomitant FAK/SRC and p-Paxillin in Mobile Tongue Squamous Cell Carcinoma. Anticancer Research. 2017; 37 (3):1313-1320.
Chicago/Turabian StyleStamatios Theocharis; Ioly Kotta-Loizou; Constantinos Giaginis; Paraskevi Alexandrou; Eugene Danas; Gerasimos Tsourouflis; Nikolaos Tsoukalas; Robert H.A. Coutts; Jason Tasoulas; Jerzy Klijanienko. 2017. "Expression and Clinical Significance of Concomitant FAK/SRC and p-Paxillin in Mobile Tongue Squamous Cell Carcinoma." Anticancer Research 37, no. 3: 1313-1320.