scholarly journals A new potyvirus isolated from Pennisetum alopecuroides with the potential to infect cereal crops

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xuedong Liu ◽  
Xi Chen ◽  
Sijia Liu ◽  
Kaitong Du ◽  
Pei Wang ◽  
...  

AbstractPennisetum plants (Pennisetum alopecuroides L.), displaying a dwarfing phenotype along with delayed flowering and mosaic symptom on leaves, were found in Beijing, China. Flexuous filamentous particles with a size of approximate 15 × 850 nm were observed in symptomatic leaves via transmission electron microscopy. Deep sequencing of small RNAs (sRNA) from symptomatic leaves and analysis of sRNA populations were then conducted to determine the genome sequence of the viral agent in diseased plant tissues. It showed that the viral agent had one positive-sense and single-stranded RNA genome, which consisted of 9717 nucleotides (nts) excluding poly(A) tail. The complete viral genome contained a large open reading frame, encoding a polyprotein of 3131 amino acids (aa). Sequence comparison and phylogenetic analysis demonstrated that the viral agent belonged to the genus Potyvirus in the family Potyviridae. In the cladogram it was most closely related to johnsongrass mosaic virus, sharing 72% nt and 65% aa sequence identity. This viral agent was provisionally named pennisetum alopecuroides mosaic virus (PalMV). Subsequently, it was confirmed that PalMV is the causal agent of this new disease in P. alopecuroides by Koch’s postulates and reverse transcription-polymerase chain reaction analysis. Moreover, maize, millet, wheat, sorghum and rice plants were experimentally infected by PalMV via rub inoculation. Consequently, we proposed that PalMV could be a potentially dangerous virus threating a wide range of cereal crops.

Author(s):  
Rami Obeid ◽  
Elias Wehbe ◽  
Mohamad Rima ◽  
Mohammad Kabara ◽  
Romeo Al Bersaoui ◽  
...  

Background: Tobacco mosaic virus (TMV) is the most known virus in the plant mosaic virus family and is able to infect a wide range of crops, in particularly tobacco, causing a production loss. Objectives: Herein, and for the first time in Lebanon, we investigated the presence of TMV infection in crops by analyzing 88 samples of tobacco, tomato, cucumber and pepper collected from different regions in North Lebanon. Methods: Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), revealed a potential TMV infection of four tobacco samples out of 88 crops samples collected. However, no tomato, cucumber and pepper samples were infected. The TMV+ tobacco samples were then extensively analyzed by RT-PCR to detect viral RNA using different primers covering all the viral genome. Results and Discussion: PCR results confirmed those of DAS-ELISA showing TMV infection of four tobacco samples collected from three crop fields of North Lebanon. In only one of four TMV+ samples, we were able to amplify almost all the regions of viral genome, suggesting possible mutations in the virus genome or an infection with a new, not yet identified, TMV strain. Conclusion: Our study is the first in Lebanon revealing TMV infection in crop fields, and highlighting the danger that may affect the future of agriculture.


Plant Disease ◽  
2012 ◽  
Vol 96 (4) ◽  
pp. 593-593 ◽  
Author(s):  
Y. K. Chen ◽  
Y. S. Chang ◽  
Y. W. Lin ◽  
M. Y. Wu

Desert rose (Adenium obesum (Forssk.) Roem. & Schult, family Apocynaceae) is native to southeastern Africa, and is a perennial potted ornamental with colorful flowers that are popular in Taiwan. Symptoms of mosaic and chlorotic ringspots and line patterns on leaves were observed in July 2010, on all eight plants in a private garden in Potzu, Chiayi, Taiwan. Spherical virus particles with a diameter of approximately 28 nm were observed in crude sap prepared from symptomatic leaves. Virus culture was established by successive local lesion isolation in Chenopodium quinoa and was maintained in the systemic host Nicotiana tabacum van Hicks. The virus was mechanically transmissible to indicator plants and induced symptoms similar to those incited by Cucumber mosaic virus (CMV). Observed symptoms included local lesions on inoculated leaves of C. amaranticolor and systemic mosaic in Cucumis sativus, Lycopersicon esculentum, N. benthamiana, N. glutinosa, and N. rustica. On N. tabacum, necrotic ringspots developed on inoculated leaves followed by systemic mosaic. Serological tests using ELISA assays and western blotting indicated that the virus reacted positively to a rabbit antiserum prepared to CMV (4). Amplicons of an expected size (1.1 kb) were obtained in reverse transcription-PCR with primers specific to the 3′-half of CMV RNA 3 (3) using total RNA extracted from infected desert rose and N. tabacum. The amplified cDNA fragment was cloned and sequenced (GenBank Accession No. AB667971). Nucleotide sequences of the coat protein open reading frame (CP ORF) (657 nt) had 92 to 96% and 76 to 77% sequence identity to those of CMV in subgroups I (GenBank Accession Nos. NC_001440, D00385, M57602, D28780, and AB008777) and II (GenBank Accession Nos. L15336, AF127976, AF198103, and M21464), respectively. Desert roses infected by Tomato spotted wilt virus (TSWV) (1) and CMV (2) have been reported previously. In spite of the plants showing mosaic symptoms similar to that caused by CMV (2) and chlorotic ringspots and line patterns caused by TSWV (1), only CMV was detected in and isolated from these infected desert roses. However, the possibility of mixed infection of CMV and other viruses were not excluded in this research. To our knowledge, this is the first report of CMV infection in desert rose plants occurring in Taiwan. References: (1) S. Adkins and C. A. Baker. Plant Dis. 89:526, 2005. (2) C. A. Baker et al. Plant Dis. 87:1007, 2003. (3) Y. K. Chen et al. Arch. Virol. 146:1631, 2001. (4) Y. K. Chen and C. C. Yang. Plant Dis. 89:529, 2005.


Author(s):  
Emdormi Rymbai ◽  

Plants are an important source of natural products and they play a vital role in the field of medicinal chemistry and pharmaceutical science. Traditional medicines have been practiced and used for thousands of years, mostly in Asian countries, where plants are the main sources of medicine. Houttuynia cordata, a herb that belongs to the family Saururaceae, has a wide range of pharmacological activities and is used traditionally in conditions like anisolobis sores, heatstroke, lung carbuncles, malaria, scrotal abscess, tonsillitis, salammoniac poison and has also been widely accepted to possess anti-cancer, anti-oxidant, anti-hypertension, anti-inflammatory, anti-mutagenic, antibacterial, anti-viral and anti-purulent activity. Moreover, it is one of the herbs that was recognized during pandemic outbreaks, such as Severe Acute Respiratory Syndrome Coronavirus (SARS CoV) in China, virulent Newcastle Disease Virus (VNDV) in Java (Indonesia) and Newcastle (England). In this review, we briefly discuss the role of H. cordata as an anti-viral agent and the possibility of developing a dosage form against Coronavirus disease-19 (COVID-19).


2021 ◽  
Vol 21 (4) ◽  
pp. 2075-2089
Author(s):  
Tiago da Silva Arouche ◽  
Anderson Yuri Martins ◽  
Teodorico de Castro Ramalho ◽  
Raul Nunes Carvalho Júnior ◽  
Fabio Luiz Paranhos Costa ◽  
...  

In the current pandemic situation raised due to COVID-19, drug reuse is emerging as the first line of treatment. The viral agent that causes this highly contagious disease and the acute respiratory syndrome coronavirus (SARS-CoV) share high nucleotide similarity. Therefore, it is structurally expected that many existing viral targets are similar to the first SARS-CoV, probably being inhibited by the same compounds. Here, we selected two viral proteins based on their vital role in the viral life cycle: Structure of the main protease SARS-CoV-2 and the structural base of the SARS-CoV-2 protease 3CL, both supporting the entry of the virus into the human host. The approved drugs used were azithromycin, ritonavir, lopinavir, oseltamivir, ivermectin and heparin, which are emerging as promising agents in the fight against COVID-19. Our hypothesis behind molecular coupling studies is to determine the binding affinities of these drugs and to identify the main amino acid residues that play a fundamental role in their mechanism of action. Additional studies on a wide range of FDA-approved drugs, including a few more protein targets, molecular dynamics studies, in vitro and biological in vivo evaluation are needed to identify combination therapy targeted at various stages of the viral life cycle. In our experiment in silico, based mainly on the molecular coupling approach, we investigated six different types of pharmacologically active drugs, aiming at their potential application alone or in combination with the reuse of drugs. The ligands showed stable conformations when analyzing the affinity energy in both proteases: ivermectin forming a stable complex with the two proteases with values −8.727 kcal/mol for Main Protease and −9.784 kcal/mol for protease 3CL, Heparin with values of −7.647 kcal/mol for the Main protease and −7.737 kcal/mol for the 3CL protease. Both conform to the catalytic site of the proteases. Our studies can provide an insight into the possible interactions between ligands and receptors, through better conformation. The ligands ivermectin, heparin and ritonavir showed stable conformations. Our in-silica docking data shows that the drugs we have identified can bind to the binding compartment of both proteases, this strongly supports our hypothesis that the development of a single antiviral agent targeting Main protease, or 3CL protease, or an agent used in combination with other potential therapies, it could provide an effective line of defense against diseases associated with coronaviruses.


Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1372-1375 ◽  
Author(s):  
Yul-Ho Kim ◽  
Ok-Sun Kim ◽  
Bong-Choon Lee ◽  
Jung-Kyung Moon ◽  
Sang-Chul Lee ◽  
...  

A new Soybean mosaic virus (SMV) strain was isolated in Korea and designated as G7H. Its virulence on eight differentials and 42 Korean soybean cultivars was compared with existing SMV strains. G7H caused the same symptoms as G7 did on the eight differential cultivars. However, it caused different symptoms on the G7-immune Korean soybean cultivars; G7H caused necrosis in Suwon 97 (Hwangkeumkong) and Suwon 181 (Daewonkong), and a mosaic symptom in Miryang 41 (Duyoukong), while G7 caused only local lesions on those varieties. The nucleotide sequence of the cylindrical inclusion region of G7H was determined and compared with other SMV strains. G7H shared 96.3 and 91.3% nucleotide similarities with G2 and G7, respectively; whereas G7 shared 95.6% nucleotide similarity with G5H.


2005 ◽  
Vol 95 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Tetsuo Maoka ◽  
Tatsuji Hataya

The complete nucleotide sequence of the genome of Papaya leaf distortion mosaic virus (PLDMV) was determined. The viral RNA genome of strain LDM (leaf distortion mosaic) comprised 10,153 nucleotides, excluding the poly(A) tail, and contained one long open reading frame encoding a polyprotein of 3,269 amino acids (molecular weight 373,347). The polyprotein contained nine putative proteolytic cleavage sites and some motifs conserved in other potyviral polyproteins with 44 to 50% identities, indicating that PLDMV is a distinct species in the genus Potyvirus. Like the W biotype of Papaya ringspot virus (PRSV), the non-papaya-infecting biotype of PLDMV (PLDMV-C) was found in plants of the family Cucurbitaceae. The coat protein (CP) sequence of PLDMV-C in naturally infected-Trichosanthes bracteata was compared with those of three strains of the P biotype (PLDMV-P), LDM and two additional strains M (mosaic) and YM (yellow mosaic), which are biologically different from each other. The CP sequences of three strains of PLDMV-P share high identities of 95 to 97%, while they share lower identities of 88 to 89% with that of PLDMV-C. Significant changes in hydrophobicity and a deletion of two amino acids at the N-terminal region of the CP of PLDMV-C were observed. The finding of two biotypes of PLDMV implies the possibility that the papaya-infecting biotype evolved from the cucurbitaceae-infecting potyvirus, as has been previously suggested for PRSV. In addition, a similar evolutionary event acquiring infectivity to papaya may arise frequently in viruses in the family Cucurbitaceae.


2021 ◽  
Author(s):  
Yuya Imamura ◽  
Moritsugu Oishi ◽  
Yuji Fujiwara ◽  
Hironobu Yanagisawa

Abstract Narcissus (Narcissus albidus) imported from the United States exhibited leaf chlorosis during post-entry quarantine. We employed next-generation sequencing (NGS) on symptomatic leaf samples and detected vallota mosaic virus (ValMV) belonging to the genus Potyvirus, family Potyviridae, as the viral agent. Sanger sequencing of PCR and rapid amplification of cDNA ends based on NGS contigs revealed that ValMV was 9,451 nucleotides (nt) in length, excluding the poly(A) tail. Nucleotide and amino acid (aa) sequences of the coat protein region had over 98% identity to previously reported ValMV isolates. At each of the 10 mature protein regions, however, sequence identity with other potyviruses was 49.5–71.9% nt and 18.3–78.9% aa, values that are below the species demarcation criteria for Potyviridae. Phylogenetic analysis revealed that our ValMV isolate is most closely related to known ValMV and is grouped within other potyviruses. Taken together, our results indicate that the newly isolated ValMV belongs to a distinct species of Potyvirus. This study provides the first report of the complete ValMV genome sequence and the first record of this virus from the narcissus.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yongqiang Li ◽  
Fei Xia ◽  
Yixuan Wang ◽  
Chenge Yan ◽  
Anning Jia ◽  
...  

Abstract Background Cannas are popular ornamental plants and widely planted for the beautiful foliage and flower. Viral disease is a major threaten to canna horticulture industry. In the city of Beijing, mosaic disease in canna was frequently observed, but the associated causal agent and its biological characterization is still unknown. Results After small RNA deep sequencing, 36,776 contigs were assembled and 16 of them shared high sequence identities with the different proteins of Sugarcane mosaic virus (SCMV) of the size ranging from 86 to 1911 nt. The complete genome of SCMV isolate (canna) was reconstructed by sequencing all cDNA clones obtained from RT-PCR and 5′\3′ RACE amplifications. SCMV-canna isolate showed to have a full RNA genome of 9579 nt in length and to share 78% nt and 85% aa sequence identities with SCMV isolates from other hosts. The phylogenetic tree constructed based on the full genome sequence of SCMV isolates allocated separately the canna-isolate in a distinct clade, indicating a new strain. Recombination analyses demonstrated that SCMV-canna isolate was a recombinant originating from a sugarcane-infecting isolate (major parent, acc. no. AJ310103) and a maize-infecting isolate (minor parent, acc. no. AJ297628). Pathogenicity test showed SCMV-canna could cause typical symptoms of mosaic and necrosis in some tested plants with varying levels of severity but was less virulent than the isolate SCMV-BJ. Field survey showed that the virus was widely distributed. Conclusions This study identified SCMV as the major agent causing the prevalent mosaic symptom in canna plants in Beijing and its genomic and biological characterizations were further explored. All these data enriched the knowledge of the viruses infecting canna and would be helpful in effective disease management in canna.


Plant Disease ◽  
2020 ◽  
Vol 104 (10) ◽  
pp. 2713-2719 ◽  
Author(s):  
Fei Xing ◽  
Wanying Hou ◽  
Sebastien Massart ◽  
Dehang Gao ◽  
Wenhui Li ◽  
...  

Apple mosaic disease is widespread in the major apple-producing areas in China and is frequently associated with the presence of the newly identified Apple necrotic mosaic virus (ApNMV), belonging to subgroup 3 of Ilarvirus genus in the family of Bromoviridae. Mosaic symptoms were also observed in a hawthorn tree. Deep sequencing revealed the hawthorn tree with mosaic symptom was infected by ApNMV, which was confirmed by RT-PCR. The complete nucleotide sequences of RNA1 (3,378 nt), RNA2 (2,778 nt), and RNA3 (1,917 nt) of ApNMV from the hawthorn were obtained, sharing 93.8 to 96.8%, 89.7 to 96.1%, and 89.8 to 94.6% nucleotide identities with those from apples and crabapples, respectively. Two hypervariable regions were found, which showed 59.2 to 85.7% and 64.0 to 89.3% sequence identities at position 142 to 198 aa and at position 780 to 864 aa in the POL protein, respectively, between the hawthorn isolate and other isolates (apple, crabapple). A grafting test demonstrated that ApNMV was easily transmissible from hawthorns to apple trees, with severe chlorosis, yellowing, mosaic, curling, and necrosis. In addition, a total of 11,685 hawthorn trees were surveyed for the incidence of mosaic disease from five provinces in China, and only six were found showing typical mosaic symptoms. A total of 145 individual trees (six symptomatic, 68 asymptomatic, and 71 other symptoms) were tested for the presence or absence of ApNMV by RT-PCR. Among them, six symptomatic, four asymptomatic, and 10 other symptomatic trees tested positive for ApNMV. Taken together, these results demonstrated that the hawthorn tree was identified as a new natural host for ApNMV with a relatively low frequency (13.8%, 20 out of 145) in the main producing areas, and it was likely to be the causal pathogen of hawthorn mosaic disease.


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