Frequency of Polyautoimmunity in Patients With Rheumatoid Arthritis and Systemic Lupus Erythematosus.

OBJECTIVE: To describe the frequency of polyautoimmunity and multiple autoimmune syndrome in patients with rheumatoid arthritis (RA) and patients with systemic lupus erythematosus (SLE). PATIENTS AND METHODS: This was a cross-sectional observational study of patients with RA, SLE, and controls without autoimmune rheumatic disease. Cases were those with RA according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria and SLE according to the 2019 American College of Rheumatology/European League Against Rheumatism criteria, consecutively recruited in a rheumatology clinic. Controls were subjects with no rheumatic autoimmune disease (AIDs) recruited in the same area. Patients filled out a questionnaire on polyautoimmunity. Variables of interest were polyautoimmunity (RA or SLE with other AIDs), whereas secondary variables were rheumatic, skin, endocrine, digestive, and neurological AIDs. Multiple autoimmune syndrome is defined as the presence of 3 or more AIDs and a family history of AIDs. Statistical analyses performed were descriptive, bivariate, and multivariate (dependent variable: polyautoimmunity). RESULTS: The study population comprised 109 patients with RA, 105 patients with SLE, and 88 controls. Polyautoimmunity was recorded in 15 patients with RA (13.8%), 43 with SLE (41%), and 2 controls (2.2%). The most frequent AID in RA was Sjögren syndrome (53.3%), followed by Hashimoto thyroiditis and psoriasis; the most frequent AIDs in SLE were Sjögren syndrome (55.8%) and antiphospholipid syndrome (30.2%), followed by Hashimoto thyroiditis. Obesity was associated with polyautoimmunity in RA (odds ratio [OR], 3.362; p = 0.034). In SLE, joint damage (OR, 2.282; p = 0.038) and anti-RNP antibodies (OR, 5.095; p = 0.028) were risk factors for polyautoimmunity, and hydroxychloroquine was a protective factor (OR, 0.190; p = 0.004). CONCLUSIONS: Polyautoimmunity is frequent in RA and even more frequent in SLE. It was associated with obesity in RA and with joint damage and anti-RNP in SLE. Hydroxychloroquine was a protector.

Incidence and case fatality rate of COVID-19 in patients with inflammatory articular diseases.

OBJECTIVE: To describe the incidence and fatality of coronavirus disease 2019 (COVID-19) and identify risk factors to fatality in patients with inflammatory articular diseases (IAD). METHODS: This is a cross-sectional observational study of IAD patients and COVID-19 with controls matched for age, sex, and RT-PCR. A control group was used to compare the cumulative incidence (CI) and case fatality rate (CFR). The main outcomes of the study were CI and CFR. Other variables included comorbidities, treatments, and characteristics of the COVID-19. Multiple logistic regression analysis was performed to investigate risk factors for fatality in patients with IAD. RESULTS: Of the 1537 patients who fulfilled the inclusion criteria, 23/1537 (1.49%) had IAD 13 (0.8%) had rheumatoid arthritis (RA), 5 psoriatic arthritis (PsA) (0.3%) and 5 axial spondyloarthritis (0.3%). There were no significant differences in CI of COVID-19 and CFR in patients with IAD compared with COVID-19 patients without IAD. In RT-PCR positive patients, the CI of COVID-19 in PsA and AS was higher. Of the 23 IAD patients, 2 RA patients (8.6%) died. The patients did no show characteristics of the COVID-19 disease different from the population. In multivariate analysis, the factor associated with fatality in patients with IAD was older age (OR [95% CI], 1.1 [1.0-1.2]). CONCLUSION: COVID-19 CI, fatality rate and other features do not seem to be increased in IAD patients. Older age was associated with fatality in patients with IAD.

Molecular Mechanisms Controlling the Disease Cycle in the Vascular Pathogen Verticillium dahliae Characterized Through Forward Genetics and Transcriptomics.

The soil-borne pathogen Verticillium dahliae has a worldwide distribution and a plethora of hosts of agronomic value. Molecular analysis of virulence processes can identify targets for disease control. In this work, we compared the global gene transcription profile of random T-DNA insertion mutant strain D-10-8F, which exhibits reduced virulence and alterations in microsclerotium formation and polar growth, with that of the wild-type strain. Three genes identified as differentially expressed were selected for functional characterization. To produce deletion mutants, we developed an updated version of one-step construction of Agrobacterium-recombination-ready plasmids (OSCAR) that included the negative selection marker HSVtk (herpes simplex virus thymidine kinase gene) to prevent ectopic integration of the deletion constructs. Deletion of VdRGS1 (VDAG_00683), encoding a regulator of G protein signaling (RGS) protein and highly upregulated in the wild type versus D-10-8F, resulted in phenotypic alterations in development and virulence that were indistinguishable from those of the random T-DNA insertion mutant. In contrast, deletion of the other two genes selected, vrg1 (VDAG_07039) and vvs1 (VDAG_01858), showed that they do not play major roles in morphogenesis or virulence in V. dahliae. Taken together the results presented here on the transcriptomic analysis and phenotypic characterization of D-10-8F and ∆VdRGS1 strains provide evidence that variations in G protein signaling control the progression of the disease cycle in V. dahliae. We propose that G protein-mediated signals induce the expression of multiple virulence factors during biotrophic growth, whereas massive production of microsclerotia at late stages of infection requires repression of G protein signaling via upregulation of VdRGS1 activity.

Mycoviruses in Biological Control: From Basic Research to Field Implementation.

Mycoviruses from plant pathogens can induce hypovirulence (reduced virulence) in their host fungi and have gained considerable attention as potential biocontrol tools. An increasing number of mycoviruses that induce fungal hypovirulence, from a wide variety of taxonomic groups, are currently being reported. Successful application of these viruses in disease management is greatly dependent on their ability to spread in the natural populations of the pathogen. Mycoviruses generally lack extracellular routes of transmission. Hyphal anastomosis is the main route of horizontal mycovirus transmission to other isolates, and conidia of vertical transmission to the progeny. Transmission efficiencies are influenced by both the fungal host and the infecting virus. Interestingly, artificial transfection methods have shown that potential biocontrol mycoviruses often have the ability to infect a variety of fungi. This expands their possible use to the control of pathogens others than those where they were identified. Mycovirus research is also focused on gaining insights into their complex molecular biology and the molecular bases of fungus-virus interactions. This knowledge could be exploited to manipulate the mycovirus and/or the host and generate combinations with enhanced properties in biological control. Finally, when exploring the use of mycoviruses in field conditions, the pathogen life style and the characteristics of the disease and crops affected will deeply impact the specific challenges to overcome, and the development of biocontrol formulations and delivery methods.

Characterization of a novel single-stranded RNA mycovirus related to invertebrate viruses from the plant pathogen Verticillium dahliae.

Fungal viruses, also known as mycoviruses, are widespread in all major groups of fungi. Mycoviruses from plant pathogens can reduce the virulence of their host fungus and have therefore potential as biological control agents. This has spurred the identification of novel mycoviruses in plant pathogens, research which is greatly contributing to our understanding of these organisms. In this work, we report the characterization of a novel monopartite mycovirus from Verticillium dahliae, the main causal agent of Verticillium wilt. This novel mycovirus, which we termed Verticillium dahliae RNA virus 1 (VdRV1), was identified in three different isolates of V. dahliae collected in olive growing areas of the Guadalquivir valley, southern Spain. We determined that the VdRV1 genome is a positive (+) single-stranded (ss) RNA, 2631 nucleotides in length, containing two open reading frames. VdRV1 showed few similarities with known mycoviruses, only with a group of unassigned (+) ssRNA mycoviruses which are related to plant viruses classified within the family Tombusviridae. However, phylogenetic analysis revealed that VdRV1 and the unassigned (+) ssRNA mycoviruses have a closer relationship with recently reported invertebrate viruses. This result indicates that as more viral sequences become available, the relationships of mycoviruses with viruses from other hosts should be reexamined. Additionally, the work supports the hypothesis of a heterogeneous origin for mycoviruses.

Fusarium oxysporum f. sp. dianthi virus 1 Accumulation Is Correlated with Changes in Virulence and Other Phenotypic Traits of Its Fungal Host.

Fusarium oxysporum f. sp. dianthi virus 1 (FodV1) was detected in isolate 116 (116V+) of Fusarium oxysporum f. sp. dianthi, reaching such a high accumulation level that it was clearly visible after agarose gel electrophoresis of total DNA extracts. FodV1 consists of four double-stranded RNA segments that correspond to a new mycovirus in the Chrysoviridae family. We obtained an isolate of F. oxysporum f. sp. dianthi 116 (116V-) with only a residual level of FodV1 RNA accumulation by single-conidia selection. Compared with 116V-, isolate 116V+ showed significant phenotypic alterations in vegetative growth and virulence. Thus, the presence of a high titer of mycovirus FodV1 was associated with a modified morphology and a reduced growth of the colonies on solid medium, and with a diminished conidiation in liquid medium. Inoculation of four susceptible carnation cultivars with either 116V- or 116V+ showed that the presence of a high titer of FodV1 was also correlated with a significantly reduced virulence of its fungal host. All of the results suggest that FodV1 could be associated with hypovirulence, identifying it as a potential biocontrol agent for Fusarium wilt of carnation. This is the first report of a mycovirus potentially associated with the induction of hypovirulence in the species F. oxysporum.

Complete genome sequence of a novel dsRNA mycovirus isolated from the phytopathogenic fungus Fusarium oxysporum f. sp. dianthi.

A novel double-stranded RNA (dsRNA) mycovirus, designated Fusarium oxysporum f. sp. dianthi mycovirus 1 (FodV1), was isolated from a strain of the phytopathogenic fungus F. oxysporum f. sp. dianthi. The FodV1 genome had four dsRNA segments, designated, from the largest to the smallest one, dsRNA 1, 2 3, and 4. Each one of these segments contained a single open reading frame (ORF). dsRNA 1 (3555 bp) and dsRNA 3 (2794 bp) encoded a putative RNA-dependent RNA polymerase (RdRp) and a putative coat protein (CP), respectively. dsRNA 2 (2809 bp) and dsRNA 4 (2646 bp) contained ORFs encoding hypothetical proteins (named P2 and P4, respectively) with unknown functions. Analysis of its genomic structure, homology searches of the deduced amino acid sequences, and phylogenetic analysis all indicated that FodV1 is a new member of the family Chrysoviridae. This is the first report of the complete genomic characterization of a mycovirus identified in the plant pathogen Fusarium oxysporum.

Genetic diversity and silencing suppression activity of the p22 protein of Tomato chlorosis virus isolates from tomato and sweet pepper.

As for other bipartite criniviruses (genus Crinivirus, family Closteroviridae), the genome of Tomato chlorosis virus encodes an RNA silencing suppressor, the protein p22, in the 3'-proximal region of RNA1. This protein has been reported as having one of the longest lasting local suppressor activities when transiently expressed in Nicotiana benthamiana. Here, we examined the genetic diversity of the p22 gene in ToCV isolates from tomato and sweet pepper. The p22 gene sequences clearly grouped into two separated clades. However, functional analysis of both types of p22 proteins indicated no evident differences in suppressor activity. Our findings provide experimental evidence that the presence of a "strong" silencing suppressor is a conserved feature of ToCV isolates.

Study of Phylogenetic Relationships Among Fusarium oxysporum f. sp. dianthi Isolates: Confirmation of Intrarace Diversity and Development of a Practical Tool for Simple Population Analyses.

Fusarium wilt, caused by Fusarium oxysporum f. sp. dianthi, is the most important disease of carnation worldwide. Knowing the diversity of the F. oxysporum f. sp. dianthi population present in a carnation growing area is a key component of preventing dramatic losses in production. Sequence analyses of partial ß-tubulin, translation elongation factor 1α genes, and the full-length ribosomal DNA intergenic spacer (IGS) were conducted to resolve phylogenetic relationships in a wide collection of Spanish F. oxysporum f. sp. dianthi isolates, along with some representatives from Italy. We found that, among the three different gene regions, the IGS sequence was the best choice to resolve phylogenetic relationships among F. oxysporum f. sp. dianthi isolates. The phylogenetic tree generated with the complete IGS region was the only one showing a clear clustering of isolates according to the molecular group (virulence grouping) and the vegetative compatibility group. In order to develop a more practical tool based on a shorter DNA sequence to quickly analyze diversity in F. oxysporum f. sp. dianthi populations, we examined IGS nucleotide alignments and identified a region of approximately 300 bp that accumulates enough "informative" changes to resolve intraspecific relationships and determine pathogenic variants in F. oxysporum f. sp. dianthi. Moreover, the "condensed" alignment of this short IGS region showing only the informative positions revealed the existence of virulence group-discriminating positions. In addition to clarifying the phylogenetic relationships among F. oxysporum f. sp. dianthi isolates of the recently described race groups by using multigene genealogies, we have developed simple tools for the phylogenetic analyses of F. oxysporum f. sp. dianthi populations and the determination of the molecular group of uncharacterized F. oxysporum f. sp. dianthi isolates.

Atypical carcinoid tumours of the lung: prognostic factors and patterns of recurrence.

BACKGROUND: Atypical carcinoids (AC) of the lung are rare intermediate-grade neuroendocrine neoplasms. Prognostic factors for these tumours are undefined. METHODS: Our cooperative group retrieved data on 127 patients operated between 1980 and 2009 because of an AC. Several clinical and pathological features were studied. RESULTS: In a univariable analysis, T-status (p=0.005), N-status (p=0.021), preoperative M-status (previously treated) (p=0.04), and distant recurrence developed during the outcome (p<0.001) presented statistically significant differences related to survival of these patients. In a multivariable analysis, only distant recurrence was demonstrated to be an independent risk factor for survival (p<0.001; HR: 13.1). During the monitoring, 25.2% of the patients presented some kind of recurrence. When we studied recurrence factors in a univariable manner, sublobar resections presented significant relationship with locoregional recurrence (p<0.001). In the case of distant recurrence, T and N status presented significant differences. Patients with preoperative M1 status presented higher frequencies of locoregional and distant recurrence (p=0.004 and p<0.001, respectively). In a multivariable analysis, sublobar resection was an independent prognostic factor to predict locoregional recurrence (p=0.002; HR: 18.1). CONCLUSIONS: Complete standard surgical resection with radical lymphadenectomy is essential for AC. Sublobar resections are related to locoregional recurrence, so they should be avoided except for carefully selected patients. Nodal status is an important prognostic factor to predict survival and recurrence. Distant recurrence is related to poor outcome.

The complete nucleotide sequence of a novel partitivirus isolated from the plant pathogenic fungus Verticillium albo-atrum.

We have characterized the bisegmented genome of a novel double-stranded RNA (dsRNA) virus isolated from the plant pathogenic fungus Verticillium albo-atrum. We determined that its larger segment (dsRNA1) was 1747 base pairs in length and potentially encoded an RNA-dependent RNA polymerase of 539 amino acids, whereas the smaller segment (dsRNA2) was 1517 base pairs long and was predicted to encode a capsid protein of 435 amino acids. Homology searches and phylogenetic analysis confirmed that, as expected from its dsRNA banding profile, the identified virus was a new member of the family Partitiviridae, and we have therefore designated it V. a lbo- a trum partitivirus 1 (VaaPV1). This is the first report of a mycovirus identified in V. albo-atrum.

Effects of the crinivirus coat protein-interacting plant protein SAHH on post-transcriptional RNA silencing and its suppression.

In plants, post-transcriptional gene silencing (PTGS) is a sequence-specific mechanism of RNA degradation induced by double-stranded RNA (dsRNA), which is processed into small interfering RNAs (siRNAs). siRNAs are methylated and, thereby, stabilized by the activity of the S-adenosylmethionine-dependent RNA methyltransferase HEN1. PTGS is amplified by host-encoded RNA-dependent RNA polymerases (RDR), which generate dsRNA that is processed into secondary siRNAs. To counteract this RNA silencing-mediated response of the host, plant viruses express proteins with silencing suppression activity. Here, we report that the coat protein (CP) of crinivirus (family Closteroviridae, genus Crinivirus) Tomato chlorosis virus, a known suppressor of silencing, interacts with S-adenosylhomocysteine hydrolase (SAHH), a plant protein essential for sustaining the methyl cycle and S-adenosylmethionine-dependent methyltransferase activity. Our results show that, by contributing to an increased accumulation of secondary siRNAs generated by the action of RDR6, SAHH enhances local RNA silencing. Although downregulation of SAHH prevents local silencing, it enhances the spread of systemic silencing. Our results also show that SAHH is important in the suppression of local RNA silencing not only by the crinivirus Tomato chlorosis virus CP but also by the multifunctional helper component-proteinase of the potyvirus Potato virus Y.

Assessment of copy-number variation in the NKG2C receptor gene in a single-tube and characterization of a reference cell panel, using standard polymerase chain reaction.

Natural killer (NK) and T-lymphocytes monitor human leukocyte antigen (HLA)-E expression through CD94:NKG2 heterodimers. Structural polymorphism is not a hallmark for NK-complex genes on chromosome 12, except for complete NKG2C deletion in some humans. We present a method for fast, simple and accurate assessment of NKG2C copy-number variation - presence or absence in the genome of an NKG2C gene, in homo- or heterozygosis, is detected by a single conventional polymerase chain reaction that yields amplicons of different lengths in each genotype. We have also determined the NKG2C genotypes of a reference cell panel comprising 13 NK- and tumour-cell lines and 39 Epstein-Barr virus transformed cells from the International Histocompatibility Workshop. Our results should facilitate research on the importance of NKG2C and its deletion for immunity.

Importance of Vaccination against SARS-CoV-2 in Patients with Interstitial Lung Disease Associated with Systemic Autoimmune Disease.

Objectives: To describe the frequency of COVID-19 and the effect of vaccination in patients with interstitial lung disease and systemic autoimmune disease (ILD-SAD) and to identify factors associated with infection and severity of COVID-19. Methods: We performed a cross-sectional multicenter study of patients with ILD-SAD followed between June and October 2021. The main variable was COVID-19 infection confirmed by a positive polymerase chain reaction (PCR) result for SARS-CoV-2. The secondary variables included severity of COVID-19, if the patient had to be admitted to hospital or died of the disease, and vaccination status. Other variables included clinical and treatment characteristics, pulmonary function and high-resolution computed tomography. Two logistic regression was performed to explore factors associated with "COVID-19" and "severe COVID-19". Results: We included 176 patients with ILD-SAD: 105 (59.7%) had rheumatoid arthritis, 49 (27.8%) systemic sclerosis, and 22 (12.54%) inflammatory myopathies. We recorded 22/179 (12.5%) SARS-CoV-2 infections, 7/22 (31.8%) of them were severe and 3/22 (13.22%) died. As to the vaccination, 163/176 (92.6%) patients received the complete doses. The factors associated with SARS-CoV-2 infection were FVC (OR (95% CI), 0.971 (0.946−0.989); p = 0.040), vaccination (OR (95% CI), 0.169 (0.030−0.570); p = 0.004), and rituximab (OR (95% CI), 3.490 (1.129−6.100); p = 0.029). The factors associated with severe COVID-19 were the protective effect of the vaccine (OR (95% CI), 0.024 (0.004−0.170); p < 0.001) and diabetes mellitus (OR (95% CI), 4.923 (1.508−19.097); p = 0.018). Conclusions: Around 13% of patients with ILD-SAD had SARS-CoV-2 infection, which was severe in approximately one-third. Most patients with severe infection were not fully vaccinated.

Resistance to Tomato yellow leaf curl virus accumulation in the tomato wild relative Solanum habrochaites associated with the C4 viral protein.

Tomato yellow leaf curl disease (TYLCD) is a severe threat to tomato crops worldwide and is caused by Tomato yellow leaf curl virus (TYLCV) and several other begomoviruses (genus Begomovirus, family Geminiviridae). Host plant resistance is the best TYLCD control method but limited sources of resistance are available. In this study, two Solanum habrochaites TYLCD-resistance sources, EELM-388 and EELM-889, were found after a wide germplasm screening and were further characterized. A consistent resistance to the widely distributed strain TYLCV-IL was observed when plants were inoculated by Bemisia tabaci or by agroinoculation using an infectious clone, with no symptoms or virus accumulation observed in inoculated plants. Moreover, the resistance was effective under field conditions with high TYLCD pressure. Two independent loci, one dominant and one recessive, were associated with EELM-889 resistance. The study shows these loci to be distinct from that of the resistance gene (Ty-1 gene) commonly deployed in commercial tomato cultivars. Therefore, both kinds of resistance could be combined to provide improved resistance to TYLCD. Four additional TYLCD-associated viruses were challenged, showing that the resistance always prevented symptom expression, although systemic infection could occur in some cases. By using chimeric and mutant expression constructs, the C4 protein was shown to be associated with the ability to result in effective systemic infection.

Comparative, validity and responsiveness of the HOOS-PS and KOOS-PS to the WOMAC physical function subscale in total joint replacement for osteoarthritis.

OBJECTIVE: To evaluate the internal consistency of the Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS) and the Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS) in total hip replacement (THR) and total knee (TKR) replacement. Construct validity and responsiveness were compared to the Western Ontario McMaster Universities' Osteoarthritis Index (WOMAC) Likert 3.0 physical function (PF) subscale and the PF excluding the items in the short measures (PF-exclusions). METHODS: Participants completed the full HOOS or KOOS, measures of fatigue, anxiety, depression and the Chronic Pain Grade (CPG) pre-surgery and the HOOS or KOOS 6 months post-surgery. Internal consistency for the HOOS-PS and KOOS-PS was calculated using Cronbach's alpha. For construct validity, it was hypothesized that correlations between the HOOS-PS or KOOS-PS and PF and PF-exclusions with fatigue, CPG, anxiety and depression and HOOS/KOOS pain scales would differ by magnitudes of <0.1. Standardized response means (SRMs) were calculated for the HOOS-PS, KOOS-PS, PF and PF-exclusions and hypothesized to be >1. RESULTS: The THR group (n=201) had a mean age of 62.3 years; 53.2% were female. The TKR group (n=248) had a mean age of 64.5 years; 63.7% were female. Cronbach's alpha was 0.79 and 0.89 for the HOOS-PS and KOOS-PS, respectively, confirming that the measures represented a homogeneous construct. The correlation of the HOOS-PS to the PF and PF-exclusions was 0.90 and 0.86, respectively; r=0.90 (PF) and r=0.85 (PF-exclusions) for the KOOS-PS. The results supported the construct validity hypotheses. For THR, the SRM was 1.5, 1.7 and 1.7 for the HOOS-PS, PF and PF-exclusions; for TKR, the SRM was 1.4, 1.5 and 1.7, respectively. CONCLUSIONS: The short HOOS-PS and KOOS-PS represent homogenous short measures of PF with similar construct validity and responsiveness to the 17-item PF. The HOOS-PS and KOOS-PS are parsimonious, valid and responsive for evaluating PF in THR and TKR.

Bronchogenic carcinoma in patients under 50 years old.

INTRODUCTION: Lung cancer in young patients is increasing in frequency. Its clinical course seems to be more aggressive than in the elderly. Our objective is to assess the clinicopathologic characteristics and survival of patients with bronchogenic carcinoma who underwent surgery at our department, comparing people younger than 50 years to older patients. MATERIALS AND METHODS: We present a retrospective study of 610 patients diagnosed with non-small-cell lung cancer operated on between 1997 and 2006. They were classified into two groups: under 50 (n=60) and equal to or over 50 (n=550). RESULTS: The proportion of women, smokers and adenocarcinoma were significantly higher in young patients. There were no significant differences in survival rate between the two groups. CONCLUSIONS: In our series, despite the differences in sex, smoking history and histology, the behaviour of the disease is similar in both age groups.

Molecular and Biological Characterization of the First Hypovirus Identified in Fusarium oxysporum.

A novel mycovirus named Fusarium oxysporum f. sp. dianthi hypovirus 2 (FodHV2) has been identified infecting isolates Fod 408 and Fod 409 of Fusarium oxysporum f. sp. dianthi from Morocco. The genome of FodHV2 is 9,444 nucleotides long excluding the poly(A) tail, and has a single open reading frame encoding a polyprotein. The polyprotein contains three highly conserved domains of UDP glucose/sterol glucosyltransferase, RNA-dependent RNA polymerase, and viral RNA helicase. In addition, particular residues of Cys, Hys, and Gly detected in the N-terminal region suggest the presence of the catalytic site of a highly diverged papain-like protease. Genomic organization, presence of particular conserved motifs, and phylogenetic analyses based on multiple alignments clearly grouped FodHV2 with the members of the family Hypoviridae. FodHV2 was transferred by hyphal anastomosis to a recipient HygR-tagged virus-free strain. The comparison of the infected and non-infected isogenic strains showed that FodHV2 did not alter the vegetative growth, neither the conidiation nor the virulence of its fungal host. Efficiency of FodHV2 transmission through the conidia was 100% in both the original and the recipient infected-isolates. To the best of our knowledge, this is the first report of a hypovirus infecting the plant pathogen F. oxysporum, and also the first one of a hypovirus detected in a fungal strain from the African continent.

Mycovirus Fusarium oxysporum f. sp. dianthi Virus 1 Decreases the Colonizing Efficiency of Its Fungal Host.

Mycoviruses that induce hypovirulence in phytopathogenic fungi are interesting because their potential use as biological control agents of the plant diseases caused by their fungal hosts. The recently identified chrysovirus Fusarium oxysporum f. sp. dianthi virus 1 (FodV1) has been associated to the induction of hypovirulence in Fusarium oxysporum f. sp. dianthi, the forma specialis of F. oxysporum that causes vascular wilt in carnation (Dianthus caryophyllus). In this work, we have used confocal laser scanner microscopy and two isogenic GFP-labeled strains of F. oxysporum f. sp. dianthi infected (V+) and not infected (V-) with the Fusarium oxysporum f. sp. dianthi virus 1, respectively, to analyze the effect of mycovirus FodV1 on the plant colonization pattern of its fungal host. Results demonstrate that FodV1-viral infection affects the speed and spatial distribution of fungal colonization into the plant. Initial stages of external root colonization were similar for both strains, but the virus-free strain colonized the internal plant tissues faster than the virus-infected strain. In addition, other differences related to the specific zone colonized and the density of colonization were observed between both F. oxysporum f. sp. dianthi strains. The hyphae of both V- and V+ strains progressed up through the xylem vessels but differences in the number of vessels colonized and of hyphae inside them were found. Moreover, as colonization progressed, V- and V+ hyphae propagated horizontally reaching the central medulla but, while the virus-free strain V- densely colonized the interior of the medulla cells, the virus-infected strain V+ appeared mainly in the intercellular spaces and with a lower density of colonization. Finally, the incidence of FodV1-viral infections in a collection of 221 isolates sampled between 2008 and 2012 in the geographic area where the originally infected isolate was obtained has been also analyzed. The very low (<2%) incidence of viral infections is discussed here. To the best of our knowledge, this work provides the first microscopic evidence about the effect of a hypovirulence-inducing mycovirus on the pattern of plant colonization by its fungal host.

Plant tissue distribution and chemical inactivation of six carnation viruses.

Carnation mottle virus (CarMV), Carnation etched ring virus (CERV), Carnation vein mottle virus (CVMV), Carnation ringspot virus (CRSV), Carnation Italian ringspot virus (CIRV) and Carnation latent virus (CLV) are the most important viruses affecting carnation crops. All except CERV are RNA viruses. Viral RNA or DNA accumulation on root, stem, leaf, sepal, petal, stamen, pistil and ovary tissues of infected carnation or Saponaria vaccaria plants was analysed by non-isotopic molecular hybridisation. High-titres of CarMV, CRSV, CIRV, and CLV accumulated in all plant tissues whereas CERV and CVMV were irregularly distributed over the plant. High-titres of all viruses accumulated in leaf, petal, stamen, pistil, and ovary tissues, so leaves or petals are a good tissue for routine diagnosis. Six chemicals were evaluated for inactivation of all carnation viruses in infected extracts. Commercial bleach at 7% (v/v) or NaOH at 0.5% (w/v) was found to inactivate all viruses after 60 s treatment in a systemic S. vaccaria bioassay.