Pepper Yellow Mosaic Virus Research Articles

Correction to: Occurrence of natural infection of Physalis peruviana with potato virus Y and pepper yellow mosaic virus in Brazil

Correction to: Occurrence of natural infection of Physalis peruviana with potato virus Y and pepper yellow mosaic virus in Brazil

Occurrence of natural infection of Physalis peruviana with potato virus Y and pepper yellow mosaic virus in Brazil

Occurrence of natural infection of Physalis peruviana with potato virus Y and pepper yellow mosaic virus in Brazil

Three species of Potyvirus genus recorded in ornamental plants, in Brazil

Pepper yellow mosaic virus on Petunia hybrida, bean yellow mosaic virus on Viola odorata and Narcissus yellow stripe virus on Narcissus cyclamineus were identified in Brazil using RT-PCR. Serology, mechanical transmission, host range, and electron microscopy were used to study the viruses further.

Translationally controlled tumour protein: A protein necessary for potyvirus intracellular multiplication that supports plant infection by unrelated viruses

AbstractThe multifunctional protein translationally controlled tumour protein (TCTP) was previously identified as necessary for infection by the potyvirus pepper yellow mosaic virus. Using turnip mosaic virus (TuMV) as a model to study potyvirus biology, we confirmed that TCTP has a positive effect on virus infection. Living cell confocal microscopy demonstrated that TCTP colocalises with 6K2‐tagged replication vesicles and with a perinuclear globular structure typically observed during potyvirus infection. Also, TCTP silenced protoplasts showed reduced virus accumulation, quantified by qRT‐PCR, which suggests an effect on virus replication, translation or other intracellular process. Finally, TCTP silencing in plants reduced the accumulation of two species belonging to Orthotospovirus and a Begomovirus genus, which are not closely related to potyviruses. The results suggest that TCTP is a general susceptibility factor to several unrelated viruses.

Breeding for Pepper yellow mosaic virus resistance and agronomic attributes in recombinant inbred lines of chili pepper (Capsicum baccatum L.) using mixed models

In peppers, developing cultivars resistant to Pepper yellow mosaic virus (PepYMV) has been a challenge for plant breeders and plant pathologists. The present work reports the phenotyping and selection of recombinant F6 lines for PepYMV resistance and good agronomic performance. Forty-seven F6 lines of Capsicum baccatum var. pendulum were tested in two experiments. The first test evaluated the plants reaction to PepYMV and was carried out in anti-aphid screen coated cages, in a completely randomized design with eight replications. As for the second experiment, the agronomic performance of the lines was evaluated in field trial, in randomized blocks design with two replications, and with six plants per plot, arranged in sets. With a selection pressure of 25%, promising agronomic lines resistant to PepYMV were identified. One highly resistant line (#345) did not have good agronomic performance, while 15 other recombined lines were identified as resistant. Four lines (#232, #400, #414 and #506) were resistant and productive, able to be included in field competitive tests, generating new cultivars of C. baccatum var. pendulum resistant to PepYMV.

Ocurrence of pepper yellow mosaic virus and cucumber mosaic virus on Capsicum chinense in the state of Amazonas, Brazil

ABSTRACT The habanero chilli pepper, Capsicum chinense is an important crop in the Amazon Basin, mainly grown by small-scale producers. Capsicum chinense plants in an experimental field in the northern Brazilian state of Amazonas were found exhibiting characteristic symptoms of viral infection. Leaf sap from symptomatic plants examined under a transmission electron microscope revealed the presence of elongated flexuous particles and isometric particles. Using molecular assays, the viruses were identified as pepper yellow mosaic virus (PepYMV) and cucumber mosaic virus (CMV). Aphids, identified as Aphis gossypii, were found colonizing the C. chinense plants in the field and may be the vector for both PepYMV and CMV. We report the first occurrence of these viruses infecting C. chinense in the state of Amazonas.

Heterosis and combining ability in bell pepper lines with resistance to multiple pathogens

ABSTRACT The aim of this study was to develop bell pepper hybrids with resistance to multiple pathogens and make inferences in regard to components of heterosis in hybrids obtained from lines presumed to be resistant to Pepper yellow mosaic virus (PepYMV), Phytophthora capsici, or Meloidogyne incognita. The studies were carried out in a greenhouse. We used ten lines, thirty experimental hybrids, and seven controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super, and Criollo de Morelos-334). For all experiments, a randomized block design was used with three replications (with plots composed of 16 plants). For evaluation of the reactions to P. capsici and to PepYMV, the percentages of asymptomatic plants were considered. For evaluation of the reactions to M. incognita, the reproduction index and the reproduction factor of the nematode were calculated. The additive gene effects were important for all the traits evaluated, and for percentage of plants resistant to PepYMV and P. capsici, the non-additive effects were also important. The alleles that control resistance to PepYMV, to P. capsici, and to M. incognita have a degree of dominance near 1, in absolute value, which indicates a favorable situation for obtaining hybrids that accumulate multiple resistance to these pathogens.

Sources of resistance to Potato virus Y and Pepper yellow mosaic virus in Solanum (section Lycopersicon) germplasm

Potato virus Y (PVY) is the type-species of the genus Potyvirus, family Potyviridae, being reported as a major tomato (Solanum lycopersicum L.) pathogen in several regions of the world. Pepper yellow mosaic virus (PepYMV) was originally described as a resistance-breaking Potato virus Y (PVY) isolate on Capsicum annuum L. cultivars, and afterwards it was also reported infecting tomatoes in Brazil. In the present work, a search for sources of resistance to both PepYMV and PVY was conducted in a collection of 119 accessions belonging to seven Solanum (section Lycopersicon) species. This germplasm was initially evaluated to PepYMV reaction by mechanical inoculation followed by symptom observations and ELISA. Potential PepYMV resistance sources were identified for the first time in S. habrochaites, S. peruvianum, S. corneliomuelleri, S. chilense, S. pimpinellifolium, and one accession derived from an interspecific cross (S. lycopersicum x S. peruvianum). A sub-group of 24 accessions with negative serology for PepYMV was also challenged with a PVY isolate, followed by serological and molecular detection with universal primers. Solanum habrochaites ‘L.03683’ and ‘L.03684’ were the only accessions found with stable resistance to both viruses. These results confirm S. habrochaites as the most important source of multiple resistance factor(s) to distinct Potyvirus species.

Assessment of resistances to multiple pathogens in experimental sweet pepper hybrids

The aim of this study was to assess resistance to major sweet pepper pathogens ( Phytophthora capsici, Pepper yellow mosaic virus – PepYMV and Meloidogyne incognita ) in a group of experimental hybrids and their respective parental lines, and to identity hybrids possibly resistant to all three pathogens. Ten parental breeding lines, thirty experimental hybrids and seven commercial controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super and Criollo de Morelos-334) were used. Each experiment was set up in a randomized complete block design with three replications. For assessment of resistance to P. capsici and PepYMV, the percent of asymptomatic plants was considered. In evaluating reactions to M. incognita, both the nematode reproduction index and the nematode reproduction factor were calculated. Five hybrids were found with resistant to all three pathogens. For all three pathogens, there was evidence that hybrids with two resistant parental lines showed slightly higher levels of pathogen resistance than those with only one resistant parental line.

Assessment of resistances to multiple pathogens in experimental sweet pepper hybrids

ABSTRACT The aim of this study was to assess resistance to some of the major sweet pepper pathogens {Phytophthora capsici, Pepper yellow mosaic virus (PepYMV) and Meloidogyne incognita} in a group of experimental hybrids and their respective parental lines, and to identify hybrids possibly resistant to all three pathogens. Ten parental breeding lines, thirty experimental hybrids and seven commercial controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super and Criollo de Morelos-334) were used. Each experiment was set up in a randomized complete block design with three replications and plots consisting of 16 plants. For assessment of resistance to P. capsici and PepYMV, the percent of asymptomatic plants was considered. In evaluating reactions to M. incognita, both the nematode reproduction index and the nematode reproduction factor were calculated. Five hybrids were found with resistance to all three pathogens. For all three pathogens, there was evidence that hybrids with two resistant parental lines showed slightly higher levels of pathogen resistance than those with only one resistant parental line.

Multiple genetic resistances in Capsicum spp.

This study aimed to identify Capsicum genotypes with resistance to bacterial spot (BS), anthracnose and Pepper yellow mosaic virus (PepYMV). Fifty-four genotypes of Capsicum spp were evaluated. Resistance reaction against BS was evaluated using three replicates, testing hypersensitivity and quantitative resistance in leaves. After evaluation, inoculated leaves were detached from the plants, being then cultivated until reproductive stage for evaluations anthracnose resistance in immature and mature fruit, totalizing 18 fruits per genotype. For PepYMV resistance was performed with five replications. Each genotype reaction was evaluated by a scoring scale, using the area under the disease progress curve for each pathosystem, and incubation period for the three systems. The latent period was evaluated only for the pathosystem Capsicum-Colletotrichum gloeosporioides. Means were grouped by the Scott-Knott test. Measures of dissimilarity matrix among the genotypes were obtained by Gower's algorithm and the grouping was obtained by the UPGMA clustering method. The accessions belonging to the Capsicum frutescens were the most susceptible to the three diseases. At least one genotype of Capsicum baccatum var. pendulum, Capsicum annuum, and Capsicum chinense showed resistance potential to BS and PepYMV, for use in breeding programs. The accession UENF 1381 (C. annuum) was resistant to the three pathogens.

Characterization of a pepper collection (Capsicum frutescens L.) from Brazil.

Germplasm banks are essential as sources of genetic variability for plant breeding programs. To characterize a Brazilian Capsicum frutescens collection, 21 malagueta and 5 Tabasco hot pepper accessions were evaluated under field and greenhouse conditions regarding morphological and molecular traits, as well as resistance to viruses. Morphological characterization was performed using 53 IPGRI (International Plant Genetic Resources Institute) descriptors, 15 vegetative, 13 inflorescence, 22 fruit, and 3 seed. Molecular characterization was carried out with 60 polymorphic markers from 29 RAPD primers. The incidence of major viruses infecting Capsicum spp, Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), Potato virus Y (PVY), Pepper yellow mosaic virus (PepYMV), Pepper mild mottle virus (PMMoV), and Cucumber mosaic virus (CMV) was evaluated by ELISA. Based on the average genetic distance among genotypes, six groups were defined for the 53 IPGRI descriptors. When considering only 11 quantitative traits (five vegetative and six fruit), six groups were also determined, and the traits plant canopy width (56.05%) and days to fruiting (25.07%) most explained the genetic diversity among genotypes. Molecular analysis defined five groups of accessions with partial correspondence to the morphological characterization data. The incidence of viruses in field-grown plants varied among genotypes and according to virus species, from 5.6% (GRSV; CNPH 3286) to 100% (PMMoV; CNPH2871), and indicated some accessions as potential sources of virus resistance. These results demonstrate the genetic variability within the group of 26 hot pepper accessions, as well as virus-resistant genotypes that can be used in breeding programs.

Translationally controlled tumour protein (TCTP) from tomato and Nicotiana benthamiana is necessary for successful infection by a potyvirus.

Translationally controlled tumour protein (TCTP) is a ubiquitously distributed protein in eukaryotes, involved in the regulation of several processes, including cell cycle progression, cell growth, stress protection, apoptosis and maintenance of genomic integrity. Its expression is induced during the early stages of tomato (Solanum lycopersicum) infection by the potyvirus Pepper yellow mosaic virus (PepYMV, a close relative of Potato virus Y). Tomato TCTP is a protein of 168 amino acids, which contains all the conserved domains of the TCTP family. To study the effects of TCTP silencing in PepYMV infection, Nicotiana benthamiana plants were silenced by virus-induced gene silencing (VIGS) and transgenic tomato plants silenced for TCTP were obtained. In the early stages of infection, both tomato and N. benthamiana silenced plants accumulated less virus than control plants. Transgenic tomato plants showed a drastic reduction in symptoms and no viral accumulation at 14 days post-inoculation. Subcellular localization of TCTP was determined in healthy and systemically infected N. benthamiana leaves. TCTP was observed in both the nuclei and cytoplasm of non-infected cells, but only in the cytoplasm of infected cells. Our results indicate that TCTP is a growth regulator necessary for successful PepYMV infection and that its localization is altered by the virus, probably to favour the establishment of virus infection. A network with putative interactions that may occur between TCTP and Arabidopsis thaliana proteins was built. This network brings together experimental data of interactions that occur in other eukaryotes and helps us to discuss the possibilities of TCTP involvement in viral infection.

Complete genome sequence of tobacco mosqueado virus.

We describe the genomic characteristics of a new potyvirus isolated from tobacco plants showing mottling ("mosqueado" in Portuguese) in southern Brazil. The complete genomic sequence consists of 9896 nucleotides, without the poly(A) tail, and shares the highest pairwise nucleotide sequence identities of 68.5% with pepper yellow mosaic virus and 68.2% with Brugmansia mosaic virus isolate D437. These identity values are below the level of 76.0% used as a criterion for species demarcation in the genus Potyvirus based on the complete genome sequence. The viral genomic organization and sequence comparison thus suggest that this virus, tentatively named "tobacco mosqueado virus" (TMosqV), represents a new potyvirus species.

The receptor-like kinase SlSOBIR1 is differentially modulated by virus infection but its overexpression in tobacco has no significant impact on virus accumulation.

The role of the tomato receptor-like kinase SlSOBIR1 in antiviral defense was investigated. SlSOBIR1 was transcriptionally modulated by unrelated viruses but its ectopic expression had no effect on virus accumulation. Leucine-rich repeat receptor-like kinases (LRR-RLK) constitute a diverse group of proteins allowing the cell to recognize and respond to the extracellular environment. In the present study we focused on a gene encoding a tomato LRR-RLK (named SlSOBIR1) involved in the host defense against fungal pathogens. Curiously, SlSOBIR1 has been previously reported to be down-regulated by Pepper yellow mosaic virus (PepYMV) infection. Here, we show that SlSOBIR1 is responsive to wounding and differentially modulated by unrelated virus infection, i.e., down-regulated by PepYMV and up-regulated by Tomato chlorotic spot virus (TCSV). Despite these divergent expression profiles, SlSOBIR1 overexpression in transgenic tobacco plants had no evident effect on TCSV and PepYMV accumulation. On the other hand, overexpression of SlSOBIR1 significantly increased the expression of selected defense genes (PR-1a and PR-6) and exacerbated superoxide production in wounded leaves. Our data indicate that the observed modulation of SlSOBIR1 expression is probably triggered by secondary effects of the virus infection process and suggest that SlSOBIR1 is not directly involved in antiviral signaling response.

Trypsin inhibitors from Capsicum baccatum var. pendulum leaves involved in Pepper yellow mosaic virus resistance.

Several plant organs contain proteinase inhibitors, which are produced during normal plant development or are induced upon pathogen attack to suppress the enzymatic activity of phytopathogenic microorganisms. In this study, we examined the presence of proteinase inhibitors, specifically trypsin inhibitors, in the leaf extract of Capsicum baccatum var. pendulum inoculated with PepYMV (Pepper yellow mosaic virus). Leaf extract from plants with the accession number UENF 1624, which is resistant to PepYMV, was collected at 7 different times (0, 24, 48, 72, 96, 120, and 144 h). Seedlings inoculated with PepYMV and control seedlings were grown in a growth chamber. Protein extract from leaf samples was partially purified by reversed-phase chromatography using a C2/C18 column. Residual trypsin activity was assayed to detect inhibitors followed by Tricine-SDS-PAGE analysis to determine the N-terminal peptide sequence. Based on trypsin inhibitor assays, trypsin inhibitors are likely constitutively synthesized in C. baccatum var. pendulum leaf tissue. These inhibitors are likely a defense mechanism for the C. baccatum var. pendulum- PepYMV pathosystem.

Peroxidase is involved in Pepper yellow mosaic virus resistance in Capsicum baccatum var. pendulum

Pathogenesis-related proteins (PRs) are among the defense mechanisms of plants that work as an important barrier to the development of pathogens. These proteins are classified into 17 families according to their amino acid sequences, serology, and/or biological or enzyme activity. The present study aimed to identify PRs associated with the pathosystem of Capsicum baccatum var. pendulum: Pepper yellow mosaic virus (PepYMV). Forty-five-day-old plants from accession UENF 1624, previously identified as resistant to PepYMV, were inoculated with the virus. Control and infected leaves were collected for analysis after 24, 48, 72, and 96 h. The inoculated and control plants were grown in cages covered with anti-aphid screens. Proteins were extracted from leaf tissue and the presence of β-1,3-glucanase, chitinase, peroxidase, and lipid transport protein was verified. No difference was observed between the protein pattern of control and infected plants when β-1,3-glucanase, chitinase, and lipid transport protein were compared. However, increased peroxidase expression was observed in infected plants at 48 and 72 h after inoculation, indicating that this PR is involved in the response of resistance to PepYMV in C. baccatum var. pendulum.

Inheritance of resistance to Pepper yellow mosaic virus in Capsicum baccatum var. pendulum

We investigated inheritance of resistance to Pepper yellow mosaic virus (PepYMV) in Capsicum baccatum var. pendulum accessions UENF 1616 (susceptible) crossed with UENF 1732 (resistant). Plants from generations P1, P2, F1, F2, BC1:1, and BC1:2 were inoculated and the symptoms were evaluated for 25 days. Subsequently, an area under the disease progress curve was calculated and subjected to generation means analysis. Only the average and epistatic effects were significant. The broad and narrow sense heritability estimates were 35.52 and 21.79%, respectively. The estimate of the minimum number of genes that control resistance was 7, indicating that resistance is polygenic and complex. Thus, methods to produce segregant populations that advocate selection in more advanced generations would be the most appropriate to produce chili pepper cultivars resistant to PepYMV.

Seleção assistida com uso de marcador molecular para resistência a potyvírus em pimentão

O objetivo deste trabalho foi determinar a presença do alelo Pvr4, que confere resistência contra o PepYMV (Pepper yellow mosaic virus), em genótipos de pimentão comunmente encontrados no mercado brasileiro, com uso de um marcador molecular codominante tipo CAPS. A resistência ao PepYMV, nos genótipos CM-334-INRA, Myr-29 e em genótipos derivados do híbrido comercial Mônica-R, foi detectada como associada à banda de 444 pb, ligada ao alelo de resistência Pvr4. As plantas resistentes homozigotas (pvr4/pvr4) mostraram uma banda de 444 pb, as suscetíveis (Pvr4+/Pvr4+) uma banda de 458 pb e as resistentes heterozigotas (Pvr4+/Pvr4) mostraram as duas bandas. No entanto, no acesso resistente CM-334-UFV, nos híbridos Magali-R e Martha-R, assim como em populações derivadas desse acesso e desses híbridos, a resistência ao PepYMV não esteve associada ao marcador CAPS. O acesso CM-334-UFV ('Criollo de Morelos-334', de Viçosa, MG) distinguiu-se do CM-334-INRA ('Criollo de Morelos-334', da França); embora ambos os acessos tenham sido resistentes ao PepYMV, apenas em CM-334-INRA foi encontrada a associação da resistência com a banda de 444 pb.

Complete genome sequence of pepper yellow mosaic virus, a potyvirus, occurring in Brazil

The complete genomic sequence of pepper yellow mosaic virus (PepYMV), a member of the genus Potyvirus, was determined. The sequence was 9745 nucleotides long, excluding the 3' poly(A) tail. The genome contained a large open reading frame encoding a polyprotein of 3085 amino acids, which contained the typically conserved motifs found in members of the genus Potyvirus and an additional P3-PIPO (pretty interesting potyvirus ORF). In a pairwise comparison with other potyvirus sequences, the full genome of PepYMV shared a maximum of 63.84 % nucleotide sequence identity with pepper mottle virus (PepMoV), followed by verbena virus Y (VVY, 62.11 %), potato virus Y (PVY, 62.07 %) and Peru tomato mosaic virus (PTV, 62.00 %). Based upon a phylogenetic analysis, PepYMV was most closely related to PepMoV and PTV, within the PVY subgroup cluster, like most potyviruses isolated in solanaceous hosts in South America.