Biological and Molecular Properties of a Begomovirus from Dicliptera sexangularis

Sixangle foldwing, Dicliptera sexangularis (Acanthaceae), showing severe yellow mottle and leaf distortion symptoms was collected from the shoreline of Calusa Island (Lee County, FL). The putative virus was transmitted from infected D. sexangularis to healthy seedlings by mechanical, whitefly (Bemisia tabaci biotype B), and graft-inoculations. Different forms of geminivirus-like DNAs were detected in total DNA extracted from infected plants by Southern blot hybridization analyses using DNA-A and -B of Bean golden mosaic virus (BGMV) from Guatemala as probes. Preliminary polymerase chain reaction experiments and sequence comparisons indicated that the virus was a distinct bipartite begomovirus. The virus was designated Dicliptera yellow mottle virus (DiYMV). Replicative dsDNAs of DiYMV were extracted, digested with selected restriction enzymes, and cloned into a plasmid vector. Both DNA-A and -B were sequenced and compared with those of other begomoviruses. Phylogenetic analyses using AV1, AC1, and BV1 nucleotide sequences indicated that DiYMV has a close relationship with the New World begomoviruses, especially those distributed in the nearby geographic areas of the Florida coast and the Caribbean Basin. However, different percent nucleotide sequence identities and phylogenetic relationships were detected when different open reading frames (ORFs) of DiYMV were compared with their counterparts from begomoviruses from the Caribbean Basin. Based on phylogenetic analyses of the AC1 and BV1 ORFs, DiYMV was closely related to BGMV type II isolates, whereas sequence comparisons of the common region and the AC4-derived amino acid sequences indicated its close relationship with Potato yellow mosaic virus from Venezuela.

Download Full-text

Weed-infecting viruses in a tropical agroecosystem present different threats to crops and evolutionary histories

PLoS ONE ◽

10.1371/journal.pone.0250066 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0250066

Author(s):

Minor R. Maliano ◽

Mônica A. Macedo ◽

Maria R. Rojas ◽

Robert L. Gilbertson

Keyword(s):

Phylogenetic Analyses ◽

Bipartite Begomoviruses ◽

Yellow Mosaic Virus ◽

Bipartite Begomovirus ◽

Caribbean Basin ◽

Degenerate Primers ◽

Infectious Clones ◽

Bean Plants ◽

Golden Yellow ◽

The Caribbean

In the Caribbean Basin, malvaceous weeds commonly show striking golden/yellow mosaic symptoms. Leaf samples from Malachra sp. and Abutilon sp. plants with these symptoms were collected in Hispaniola from 2014 to 2020. PCR tests with degenerate primers revealed that all samples were infected with a bipartite begomovirus, and sequence analyses showed that Malachra sp. plants were infected with tobacco leaf curl Cuba virus (TbLCuCV), whereas the Abutilon sp. plants were infected with a new bipartite begomovirus, tentatively named Abutilon golden yellow mosaic virus (AbGYMV). Phylogenetic analyses showed that TbLCuCV and AbGYMV are distinct but closely related species, which are most closely related to bipartite begomoviruses infecting weeds in the Caribbean Basin. Infectious cloned DNA-A and DNA-B components were used to fulfilled Koch’s postulates for these diseases of Malachra sp. and Abutilon sp. In host range studies, TbLCuCV also induced severe symptoms in Nicotiana benthamiana, tobacco and common bean plants; whereas AbGYMV induced few or no symptoms in plants of these species. Pseudorecombinants generated with the infectious clones of these viruses were highly infectious and induced severe symptoms in N. benthamiana and Malachra sp., and both viruses coinfected Malachra sp., and possibly facilitating virus evolution via recombination and pseudorecombination. Together, our results suggest that TbLCuCV primarily infects Malachra sp. in the Caribbean Basin, and occasionally spills over to infect and cause disease in crops; whereas AbGYMV is well-adapted to an Abutilon sp. in the Dominican Republic and has not been reported infecting crops.

Download Full-text

Genetic Diversity Among Geminiviruses Associated with the Weed Species Sida spp., Macroptilium lathyroides, and Wissadula amplissima from Jamaica

Plant Disease ◽

10.1094/pdis.1997.81.11.1251 ◽

1997 ◽

Vol 81 (11) ◽

pp. 1251-1258 ◽

Cited By ~ 40

Author(s):

Marcia E. Roye ◽

Wayne A. McLaughlin ◽

Medhat K. Nakhla ◽

Douglas P. Maxwell

Keyword(s):

Genetic Diversity ◽

Amino Acid ◽

Mosaic Virus ◽

Amino Acid Sequences ◽

Yellow Mosaic Virus ◽

Weed Species ◽

Degenerate Primers ◽

Sequence Comparisons ◽

The Common ◽

Macroptilium Lathyroides

Genetic diversity among geminiviruses associated with three common weeds in Jamaica was studied using digoxigenin-labeled geminiviral DNA probes, polymerase chain reaction with degenerate primers for DNA-A and DNA-B, nucleic acid sequencing, and derived amino acid sequences. Geminiviruses with bipartite genomes were found in Sida spp., Macroptilium lathyroides, and Wissadula amplissima. The geminiviruses detected in Sida spp. and M. lathyroides were nearly identical and were both designated Sida golden mosaic geminivirus (SidGMV-JA), whereas the geminivirus in W. amplissima was sufficiently different to be designated Wissadula golden mosaic geminivirus (WGMV). Nucleotide sequence comparisons of the common regions and the N-terminal regions of the AC1 (rep) and AV1 ORFs, together with the derived amino acid sequence comparisons of the N-terminal parts of BC1 and BV1 ORFs were used to determine their similarities to other geminiviruses. SidGMV-JA was most similar to potato yellow mosaic geminivirus (PYMV). We propose that these two geminiviruses (SidGMV-JA and PYMV) define a new geminivirus cluster, the potato yellow mosaic virus (PYMV) cluster. WGMV was most similar to members of the Abutilon mosaic virus cluster but is not likely to be included in the Abutilon phylogenetic group because of the divergent sequence of the common region. These results indicate that geminiviruses infecting some weeds in Jamaica are distinct from crop-infecting geminiviruses in Jamaica and define a new geminivirus cluster.

Download Full-text

Chayote mosaic virus, a New Tymovirus Infecting Cucurbitaceae

Phytopathology ◽

10.1094/phyto.2000.90.10.1098 ◽

2000 ◽

Vol 90 (10) ◽

pp. 1098-1104 ◽

Cited By ~ 9

Author(s):

Juan J. Bernal ◽

Ignacio Jiménez ◽

Manuel Moreno ◽

Melanie Hord ◽

Carmen Rivera ◽

...

Keyword(s):

Mosaic Virus ◽

Protein Gene ◽

Phylogenetic Analyses ◽

Disease Symptoms ◽

Close Relationship ◽

Andean Potato ◽

The Caribbean ◽

Asymptomatic Infections ◽

Relationship Of ◽

Host Families

Chayote mosaic virus (ChMV) is a putative tymovirus isolated from chayote crops in Costa Rica. ChMV was characterized at the host range, serological, and molecular levels. ChMV was transmitted mechanically and induced disease symptoms mainly in Cucurbitaceae hosts. Asymptomatic infections were detected in other host families. Serologically, ChMV is related to the Andean potato latent virus (APLV) and the Eggplant mosaic virus (EMV), both members of the genus Tymovirus infecting solanaceous hosts in the Caribbean Basin and South America. The sequence of the genomic RNA of ChMV was determined and its genetic organization was typical of tymoviruses. Comparisons with other tymoviral sequences showed that ChMV was a new member of the genus Tymovirus. The phylogenetic analyses of the coat protein gene were consistent with serological comparisons and positioned ChMV within a cluster of tymoviruses infecting mainly cucurbit or solanaceous hosts, including APLV and EMV. Phylogenetic analyses of the replicase protein gene confirmed the close relationship of ChMV and EMV. Our results suggest that ChMV is related to two tymoviruses (APLV and EMV) of proximal geographical provenance but with different natural host ranges. ChMV is the first cucurbit-infecting tymovirus to be fully characterized at the genomic level.

Download Full-text

Macroptilium yellow mosaic virus, a New Begomovirus Infecting Macroptilium lathyroides in Cuba

Plant Disease ◽

10.1094/pdis.2002.86.9.1049b ◽

2002 ◽

Vol 86 (9) ◽

pp. 1049-1049 ◽

Cited By ~ 9

Author(s):

P. L. Ramos ◽

A. Fernández ◽

G. Castrillo ◽

L. Díaz ◽

A. L. Echemendía ◽

...

Keyword(s):

Amino Acid ◽

Mosaic Virus ◽

Restriction Fragment ◽

Amino Acid Sequences ◽

Yellow Mosaic Virus ◽

Bipartite Begomovirus ◽

Degenerate Primers ◽

Cp Gene ◽

Golden Yellow ◽

Macroptilium Lathyroides

Macroptilium lathyroides (L) is a weed that is widely distributed in Cuba. Frequently, leaves show bright yellow mosaic symptoms, which suggest the incidence of a viral disease. Since begomovirus occurrence in Macroptilium lathyroides has been previously reported in other islands of the Caribbean (1,3), symptomatic plants from three distant places in Cuba (Havana, Villa Clara, and Camaguey), were collected and tested for the presence of begomoviruses. Plant DNA extracts were analyzed by Southern blot hybridization and polymerase chain reaction with two sets of degenerate primers (2). The presence of a bipartite begomovirus was evident through strong hybridization signals obtained with the DNA-A and DNA-B of Taino tomato mottle virus as probes at low stringency. Furthermore, 1.4-kb and 1.2-kb PCR amplified fragments were obtained with DNA-A degenerate primers, PAL1v1978-PAR1c715 and PAL1c1960-PAR1v722, respectively. Both PCR fragments from the samples from the three locations were cloned, and restriction fragment length polymorphism analysis of the 1.4-kb fragments were performed using PstI, EcoRI, HincII, XbaI and BglII. Restriction fragment patterns were the same for the three clones. The DNA-A sequence (GenBank Accession No. AJ344452) of the isolate from Villa Clara was compared with sequences available for other geminiviruses using CLUSTAL program. For the coat protein (CP) gene, the comparisons had the highest percentage of identity with various strains of Bean golden yellow mosaic virus (BGYMV, GenBank Accession Nos. AF173555, M91604, and L01635) (85 to 87% and 93 to 94%, nucleotide and amino acid sequences, respectively). For Rep gene (1,044 nt), the best percentages of identities were with BGYMV (81 to 82% and 80 to 82% nucleotide and amino acid sequences, respectively), Tomato leaf crumple virus (GenBank Accession No. AF101476) (78 and 81%, nucleotide and amino acid sequences, respectively), and Sida golden mosaic virus from Florida (GenBank Accession No. AF049336) (78 and 79%, nucleotide and amino acid sequences, respectively). Finally, the comparative analysis of the intergenic region (i.e. the common region plus the CP gene promoter) had the highest identity with BGYMV (56 to 55%) and Tomato severe rugose virus (GenBank Accession No. AY029750) (49%). Interestingly, this virus has in this region the three G-box elements that are characteristic of BGYMV but it differs in the Rep protein-binding iterative motif that is GGTGA instead of GGAGA, for BGYMV. These data indicate that this virus is a new begomovirus and the name of Macroptilium yellow mosaic virus (MaYMV) is proposed. References: (1) A. M. Idris et al. Plant Dis. 83:1071, 1999. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993. (3) M. E. Roye et al. Plant Dis. 81:1251, 1997.

Download Full-text

High Prevalence of Three Potyviruses Infecting Cucurbits in Oklahoma and Phylogenetic Analysis of Cucurbit Aphid-Borne Yellows Virus Isolated from Pumpkins

Pathogens ◽

10.3390/pathogens10010053 ◽

2021 ◽

Vol 10 (1) ◽

pp. 53

Author(s):

Vivek Khanal ◽

Harrington Wells ◽

Akhtar Ali

Keyword(s):

Phylogenetic Analysis ◽

Mosaic Virus ◽

Zucchini Yellow Mosaic Virus ◽

Yellow Mosaic Virus ◽

Watermelon Mosaic Virus ◽

High Prevalence ◽

The Us ◽

Close Relationship ◽

The Status ◽

Low Incidence

Field information about viruses infecting crops is fundamental for understanding the severity of the effects they cause in plants. To determine the status of cucurbit viruses, surveys were conducted for three consecutive years (2016–2018) in different agricultural districts of Oklahoma. A total of 1331 leaf samples from >90 fields were randomly collected from both symptomatic and asymptomatic cucurbit plants across 11 counties. All samples were tested with the dot-immunobinding assay (DIBA) against the antisera of 10 known viruses. Samples infected with papaya ringspot virus (PRSV-W), watermelon mosaic virus (WMV), zucchini yellow mosaic virus (ZYMV), and cucurbit aphid-borne-yellows virus (CABYV) were also tested by RT-PCR. Of the 10 viruses, PRSV-W was the most widespread, with an overall prevalence of 59.1%, present in all 11 counties, followed by ZYMV (27.6%), in 10 counties, and WMV (20.7%), in seven counties, while the remaining viruses were present sporadically with low incidence. Approximately 42% of the infected samples were positive, with more than one virus indicating a high proportion of mixed infections. CABYV was detected for the first time in Oklahoma, and the phylogenetic analysis of the first complete genome sequence of a CABYV isolate (BL-4) from the US showed a close relationship with Asian isolates.

Download Full-text

Genome-Wide Identification and Expression Analysis of the Histone Deacetylase Gene Family in Wheat (Triticum aestivum L.)

Plants ◽

10.3390/plants10010019 ◽

2020 ◽

Vol 10 (1) ◽

pp. 19

Author(s):

Peng Jin ◽

Shiqi Gao ◽

Long He ◽

Miaoze Xu ◽

Tianye Zhang ◽

...

Keyword(s):

Abiotic Stress ◽

Gene Family ◽

Mosaic Virus ◽

Stress Responses ◽

Viral Infections ◽

Phylogenetic Analyses ◽

Plant Viruses ◽

Gene Family Evolution ◽

Yellow Mosaic Virus ◽

Wheat Yellow Mosaic Virus

Histone acetylation is a dynamic modification process co-regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). Although HDACs play vital roles in abiotic or biotic stress responses, their members in Triticumaestivum and their response to plant viruses remain unknown. Here, we identified and characterized 49 T. aestivumHDACs (TaHDACs) at the whole-genome level. Based on phylogenetic analyses, TaHDACs could be divided into 5 clades, and their protein spatial structure was integral and conserved. Chromosomal location and synteny analyses showed that TaHDACs were widely distributed on wheat chromosomes, and gene duplication has accelerated the TaHDAC gene family evolution. The cis-acting element analysis indicated that TaHDACs were involved in hormone response, light response, abiotic stress, growth, and development. Heatmaps analysis of RNA-sequencing data showed that TaHDAC genes were involved in biotic or abiotic stress response. Selected TaHDACs were differentially expressed in diverse tissues or under varying temperature conditions. All selected TaHDACs were significantly upregulated following infection with the barley stripe mosaic virus (BSMV), Chinese wheat mosaic virus (CWMV), and wheat yellow mosaic virus (WYMV), suggesting their involvement in response to viral infections. Furthermore, TaSRT1-silenced contributed to increasing wheat resistance against CWMV infection. In summary, these findings could help deepen the understanding of the structure and characteristics of the HDAC gene family in wheat and lay the foundation for exploring the function of TaHDACs in plants resistant to viral infections.

Download Full-text

Increase in Zucchini yellow mosaic virus Symptom Severity in Tolerant Zucchini Cultivars Is Related to a Point Mutation in P3 Protein and Is Associated with a Loss of Relative Fitness on Susceptible Plants

Phytopathology ◽

10.1094/phyto.2003.93.12.1478 ◽

2003 ◽

Vol 93 (12) ◽

pp. 1478-1484 ◽

Cited By ~ 57

Author(s):

C. Desbiez ◽

A. Gal-On ◽

M. Girard ◽

C. Wipf-Scheibel ◽

H. Lecoq

Keyword(s):

Mosaic Virus ◽

Point Mutation ◽

Zucchini Yellow Mosaic Virus ◽

Genetic Load ◽

Yellow Mosaic Virus ◽

Relative Fitness ◽

Interspecific Crosses ◽

Mixed Infections ◽

Wild Type ◽

Sequence Comparisons

Zucchini yellow mosaic virus (ZYMV, Potyvirus) is a very damaging cucurbit virus worldwide. Interspecific crosses with resistant Cucurbita moschata have led to the release of “resistant” zucchini squash (C. pepo) F1 hybrids. However, although the resistance is almost complete in C. moschata, the commercial C. pepo hybrids are only tolerant. ZYMV evolution toward increased aggressiveness on tolerant hybrids was observed in the field and was obtained experimentally. Sequence comparisons and recombination experiments revealed that a point mutation in the P3 protein of ZYMV was enough to induce tolerance breaking. Competition experiments were performed between quasi-isogenic wild-type, and aggressive variants of ZYMV distinguished by monoclonal antibodies. The aggressive mutants were more fit than wild-type strains in mixed infections of tolerant zucchini, but they presented a drastic fitness loss in mixed infections of susceptible zucchini or melon. Thus, the ability to induce severe symptoms in tolerant zucchini is related to a genetic load in susceptible zucchini, but also on other susceptible hosts. This represents the first quantitative study of the fitness cost associated with tolerance breaking for a plant virus. Thus, although easily broken, the tolerance might prove durable in some conditions if the aggressive variants are counterselected in susceptible crops.

Download Full-text

An expanded concept of Madisonia including miscellaneous species of Pleurothallidinae (Orchidaceae): evidence from molecular analysis

Phytotaxa ◽

10.11646/phytotaxa.505.1.5 ◽

2021 ◽

Vol 505 (1) ◽

pp. 71-84

Author(s):

ERIC DE CAMARGO SMIDT ◽

A. L. V. TOSCANO DE BRITO ◽

ANNA VICTORIA SILVÉRIO R. MAUAD ◽

NICOLÁS GUTIÉRREZ MORALES

Keyword(s):

Molecular Analysis ◽

Amazon Basin ◽

Phylogenetic Analyses ◽

Monotypic Genus ◽

Phylogenetic Information ◽

Close Relationship ◽

The Caribbean ◽

Taxonomic Studies ◽

Expanded Concept ◽

New Nomenclatural Combinations

Prior taxonomic studies in subtribe Pleurothallidinae have suggested a close relationship between miscellaneous species featuring long-repent, segmented rhizomes, abbreviated ramicauls, few-flowered inflorescences, and flowers with partially connate sepals and trilobed lip. The lack of phylogenetic information for most species has prevented further conclusions or changes in their taxonomy; and as a result, they are currently assigned to several unrelated genera: Anathallis, Madisonia, Pabstiella, Pleurothallis, Sansonia and Specklinia. We performed phylogenetic analyses using nuclear (nrITS) and five plastid (matK, psbD-trnT, rps16-trnQ, trnH-psbA and trnS-trnG) markers and demonstrated that these species form an isolated clade which requires generic recognition. The name Madisonia, previously a monotypic genus endemic of the Amazon basin, is re-circumscribed and expanded to include nine species distributed in the Atlantic Rainforest and the Caribbean. Eight new nomenclatural combinations are proposed.

Download Full-text

Two Newly Described Begomoviruses of Macroptilium lathyroides and Common Bean

Phytopathology ◽

10.1094/phyto.2003.93.7.774 ◽

2003 ◽

Vol 93 (7) ◽

pp. 774-783 ◽

Cited By ~ 25

Author(s):

A. M. Idris ◽

E. Hiebert ◽

J. Bird ◽

J. K. Brown

Keyword(s):

Common Bean ◽

Mosaic Virus ◽

Dna Sequences ◽

Western Hemisphere ◽

Yellow Mosaic Virus ◽

Nucleotide Identity ◽

Caribbean Region ◽

Golden Yellow ◽

The Caribbean ◽

Macroptilium Lathyroides

Macroptilium lathyroides, a perennial weed in the Caribbean region and Central America, is a host of Macroptilium yellow mosaic Florida virus (MaYMFV) and Macroptilium mosaic Puerto Rico virus (MaMPRV). The genomes of MaYMFV and MaMPRV were cloned from M. lathyroides and/or field-infected bean and the DNA sequences were determined. Cloned A and B components for both viruses were infectious when inoculated to M. lathyroides and common bean. Comparison of the DNA sequences for cloned A and B components with well-studied begomovirus indicated that MaMPRV (bean and M. lathyroides) and MaYMFV (M. lathyroides) are unique, previously undescribed begomo-viruses from the Western Hemisphere. Phylogenetic analysis of viral A components indicated that the closest relative of MaYMFV are members of the Bean golden yellow mosaic virus (BGYMV) group, at 76 to 78% nucleotide identity, whereas the closest relative for the A component of MaMPRV was Rhynchosia golden mosaic virus at 78% nucleotide identity. In contrast, BGYMV is the closest relative for the B component of both MaYMFV and MaMPRV, with which they share ≈68.0 and ≈72% identity, respectively. The incongruent taxonomic placement for the bipartite components for MaMPRV indicates that they did not evolve entirely along a common path. MaYMFV and MaMPRV caused distinctive symptoms in bean and M. lathyroides and were transmissible by the whitefly vector and by grafting; however, only MaYMFV was mechanically transmissible. The experimental host range for the two viruses was similar and included species within the families Fabaceae and Malvaceae, but only MaYMFV infected Malva parviflora and soybean. These results collectively indicate that MaMPRV and MaYMFV are new, previously undescribed species of the BGYMV group, a clade previously known to contain only strains and isolates of BGYMV from the Caribbean region that infect Phaseolus spp. Both MaYMFV and MaMPRV may pose an economic threat to bean production in the region.

Download Full-text