scholarly journals First Report of Alfalfa mosaic virus in Chayote in Italy

Plant Disease ◽  
2020 ◽  
Author(s):  
Giuseppe Parrella ◽  
Elisa Troiano ◽  
Chantal Faure ◽  
Armelle Marais ◽  
Thierry Candresse
Keyword(s):  
Mosaic Virus ◽  
Illumina Sequencing ◽  
Infected Plant ◽  
Alfalfa Mosaic Virus ◽  
Climatic Conditions ◽  
Post Inoculation ◽  
Chenopodium Amaranticolor ◽  
Genomic Rnas ◽  
Campania Region ◽  
Sequence Identity

Chayote (Sechium edule (Jacq.) Sw.) is a vigorous perennial and climbing cucurbits, native to Mesoamerica, and cultivated for alimentary purposes in the American continent, Australia, New Zealand, South Europe, Asia and Africa. During spring 2019, some chayote plants showing bright yellow vein banding rings and lines were observed in a private garden in South Italy (Campania region). Symptoms coalesced in some leaves, covering almost the whole foliar area. Double-stranded RNAs were extracted from symptomatic leaves of a single chayote plant and reverse-transcribed, randomly amplified, and submitted to Illumina sequencing (Marais et al., 2018). Reads were assembled using CLC Genomics Workbench 11.1 (http://www.clcbio.com). Contigs were then annotated by Blastn and Blastx comparison with the Genbank database, which allowed the identification of eight contigs of between 380 and 980 nucleotides sharing significant identity with alfalfa mosaic virus (AMV) genomic RNAs. No other viral contigs were identified. Mapping of reads on AMV genomic RNAs identified 4,209 AMV reads (1.26% of total reads) and allowed the scaffolding of the contigs into three scaffolds corresponding to the three AMV genomic RNAs. To complete the sequence of the AMV chayote isolate genome (named See-1), primers were designed from the contig sequences and used to amplify RACE PCR products spanning the 5′ and 3′ terminal regions of the three genomic RNAs using the SMARTer™ RACE cDNA Amplification Kit (Clontech, China). All amplicons were cloned into the pGEM-T vector (Promega, USA) and sequenced (three clones for each amplicon) by Microsynth Seqlab (Microsynth AG, Switzerland). Finally, the complete genomic sequences of the three RNAs were assembled by MacVector 17.5 (MacVector Inc., USA). The RNA1, RNA2 and RNA3 of See-1 are 3,643, 2,593 and 2,037 nt respectively (GenBank accession Nos. MT093209 to MT093211), and share the highest nt sequence identity with the RNA1 and RNA3 of AMV isolate (HZ) from tobacco (99.5% for RNA1, HQ316635; 98.7% for RNA3, HQ316637) and with the RNA2 of isolate AMV-Gym from Gynostemma pentaphyllum (98.1%, MH332898), both from China. AMV isolate See-1 was classified as belonging to subgroup I based on the presence of a BamH I and two AvaII sites in the CP ORF (Parrella et al., 2000). Reverse transcription polymerase chain reaction, using primers targeting the CP gene (Parrella et al., 2000), confirmed AMV infection in three symptomatic cayote plants including that used for Illumina sequencing, with 100% of nt sequence identity of amplicons. Three plants each of Chenopodium amaranticolor, Nicotiana benthamiana and Solanum lycopersicon were mechanically inoculated with sap from isolate See-1 infected plant, leading to the appearance of typical AMV symptoms in all three hosts ten days post-inoculation (Jaspars & Bos, 1980). This note describes the first detection of AMV in cayote in Italy and, to the best of our knowledge, in the world. In some areas of Southern Italy, climatic conditions are favorable enough to allow chayote development in the wild. Further studies would be desirable to determine the distribution and incidence of AMV in chayote and to understand the possibility that this species may play a role in AMV epidemiology, representing a threat to other susceptible crops.

scholarly journals Araujia sericifera New Host of Alfalfa mosaic virus in Italy

Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1387-1387 ◽  
Author(s):  
G. Parrella ◽  
B. Greco ◽  
G. Cennamo ◽  
R. Griffo ◽  
A. Stinca
Keyword(s):  
Mosaic Virus ◽  
Invasive Plant ◽  
Alfalfa Mosaic Virus ◽  
Rt Pcr ◽  
Systemic Necrosis ◽  
New Host ◽  
Campania Region ◽  
Bright Yellow ◽  
Italian Isolate ◽  
Local Lesions

Araujia sericifera Brot. (Fam. Apocynaceae) is an evergreen climbing plant native of South America, originally introduced in Europe as an ornamental. In spring 2012, virus-like symptoms including bright yellow mosaic of calico-type and leaf distortion were observed in three A. sericifera plants growing in an abandoned field located in Pomigliano d'Arco (Campania region, Italy). Leaves from the three plants were collected and examined using commercial antisera (Bioreba AG, Reinach, Switzerland) by double antibody sandwich (DAS)-ELISA against Cucumber mosaic virus (CMV), Alfalfa mosaic virus (AMV), and by indirect plate trapped antigen (PTA)-ELISA against potyviruses (Potygroup test). Only AMV was detected serologically in the three A. sericifera samples. The virus was mechanically transmitted from the ELISA-positive samples to four plants each of Chenopodium quinoa, C. amaranticolor, tobacco (Nicotiana tabacum cv. Xanthi nc), cowpea (Vigna unguiculata, cv. Black eyes), basil (Ocimum basilicum, cv. Gigante), and tomato (Solanum lycopersicum cv. San Marzano), using chilled 0.03 M sodium phosphate buffer, containing 0.2% sodium diethyldithiocarbamate, 75 mg/ml of active charcoal, and traces of Carborundum (600 mesh). Inoculated plants were kept in an insect-proof greenhouse with natural illumination and temperatures of 24 and 18°C day/night. Under these conditions, plants showed the following symptoms after 1 to 3 weeks, consistent with symptoms caused by AMV (1): chlorotic local lesions following by mosaic in C. quinoa and C. amaranticolor, reddish local lesions following by mosaic in cowpea, necrotic local lesions followed by systemic necrosis in tomato, bright yellow mosaic (calico type) in basil, and mosaic and strong deformation of the apical leaves in tobacco. The presence of AMV in ELISA-positive A. sericifera and host plants was further confirmed by conventional reverse transcription (RT)-PCR. Total RNAs were extracted with an RNeasy Plant Mini Kit (Qiagen, Hilden, Germany). RT-PCR was performed with the One-Step RT-PCR Kit (Qiagen) using primers for the coat protein gene (CP) previously used for the molecular characterization of AMV isolates (2). An Italian isolate of AMV from Lavandula stoechas (GenBank Accession No. FN667967) and RNA extracted from a healthy A. sericifera plant were used as positive and negative controls, respectively. An amplicon of the correct predicted size (∼750 bp) was obtained from each of the infected plants assayed, and that derived from A. sericifera isolate Ars2 was purified (QIAqick PCR Purification Kit, Qiagen), cloned in pGEMT easy vector (Promega, Fitchburg, WI) and sequenced (HF570950). Sequence analysis of the CP gene, conducted with MEGA5 software, revealed the highest nucleotide identity of 98% (99% amino acid identity) with the AMV isolate Tef-1 (FR854391), an isolate belonging to subgroup I (3). To our knowledge, this is the first report of AMV infecting A. sericifera in Italy. Since A. sericifera is considered an invasive plant, in continuous expansion to new areas in Italy and in other European countries, particular attention should be paid to the possibility that this species may play a role in the epidemiology of aphid-transmitted viruses such as AMV and CMV, representing a threat to susceptible crops growing nearby. References: (1) G. Marchoux et al. Page 163 in: Virus des Solanacées. Quae éditions, Versailles, 2008. (2) G. Parrella et al. Arch. Virol. 145:2659, 2000. (3) G. Parrella et al. Plant Dis. 96:249, 2012.

scholarly journals First Report of Tobacco rattle virus and Cucumber mosaic virus in Phlox paniculata in France

Plant Disease ◽  
2007 ◽  
Vol 91 (3) ◽  
pp. 322-322 ◽  
Author(s):  
L. Cardin ◽  
J. P. Onesto ◽  
I. Bornard ◽  
B. Moury
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Tobacco Rattle Virus ◽  
Post Inoculation ◽  
Mild Mosaic ◽  
Rt Pcr ◽  
Chenopodium Amaranticolor ◽  
Phlox Paniculata ◽  
Local Lesions ◽  
Das Elisa

Phlox paniculata L., a perennial plant from the family Polemoniaceae, is cultivated as an ornamental in gardens and for cut-flower production. In spring 2003, two types of symptoms were observed in P. paniculata plants grown for cut flowers on a farm in the Var department, France. Some plants showed a mild leaf mosaic while others showed leaf browning and delayed growth. In plants showing mild mosaic, Cucumber mosaic virus (CMV) was detected on the basis of the symptoms exhibited by a range of inoculated plants, the observation of isometric particles (approximately 30 nm) with the electron microscope in crude sap preparations from the infected plants, and the positive reaction in double-antibody sandwich (DAS)-ELISA to polyclonal antibodies raised against CMV (1). In double-immunodiffusion analysis, the five tested isolates were shown to belong to group II of CMV strains. To determine if CMV was responsible for the symptoms observed, one isolate was multiplied in Nicotiana tabacum cv. Xanthi-nc plants after isolation from local lesions on Vigna unguiculata and mechanically inoculated to 12 1-year-old P. paniculata plants. At 3 months post inoculation (mpi), all plants showed mild mosaic and CMV was detected by DAS-ELISA. In sap preparations from P. paniculata plants showing leaf browning symptoms, rod-shaped particles with two distinct sizes of 190 to 210 and 70 to 90 nm long, typical of those associated with tobraviruses, were revealed using electron microscopy. Local lesions typical of Tobacco rattle virus (TRV) were observed after inoculation of N. tabacum cv. Xanthi-nc, Chenopodium amaranticolor, and C. quinoa. Total nucleic acid preparations were prepared from symptomatic plants, and amplicons of the expected size (463 bp) were generated by reverse-transcription (RT)-PCR using primers specific to TRV RNA 1 (4). The nucleotide sequence of one amplicon was 93.6% identical to the sequence of a reference TRV isolate (GenBank Accession No. AJ586803). Twelve 1-year-old P. paniculata plants were mechanically inoculated with an extract of infected tissues from one symptomatic P. paniculata plant. TRV was detected 2 to 6 mpi in apical leaves of all inoculated plants by RT-PCR, although the plants did not express symptoms. Since no other pathogens were detected in the source plants, it is plausible that the lack of symptoms in back-inoculated plants is either due to a long incubation period or an interaction with particular environmental factors such as cold conditions. The survey of approximately 200 plants revealed that approximately 7, 10, and 1% were infected by TRV, CMV, or by both viruses, respectively. CMV and TRV were previously detected in P. paniculata in Latvian SSR and in Lithuania (2,3). These results show that sanitary selection of P. paniculata prior to vegetative propagation should include a screening for TRV and CMV infections. References: (1) J.-C. Devergne et al. Ann. Phytopathol. 10:233, 1978. (2) Y. Ignab and A. Putnaergle. Tr. Latv. S.-Kh. Akad. 118:27, 1977. (3) M. Navalinskiene and M. Samuitiene. Biologija 1:52, 1996. (4) D. J. Robinson. J. Virol. Methods 40:57, 1992.

scholarly journals Arabidopsis m6A demethylase activity modulates viral infection of a plant virus and the m6A abundance in its genomic RNAs

2017 ◽  
Vol 114 (40) ◽  
pp. 10755-10760 ◽  
Author(s):  
Mireya Martínez-Pérez ◽  
Frederic Aparicio ◽  
Maria Pilar López-Gresa ◽  
Jose María Bellés ◽  
Jesus A. Sánchez-Navarro ◽  
...  
Keyword(s):  
Viral Infection ◽  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Coat Proteins ◽  
Genomic Rnas ◽  
Rna Molecules ◽  
Regulatory Strategy ◽  
Demethylase Activity ◽  
Cellular Machinery

N6-methyladenosine (m6A) is an internal, reversible nucleotide modification that constitutes an important regulatory mechanism in RNA biology. Unlike mammals and yeast, no component of the m6A cellular machinery has been described in plants at present. m6A has been identified in the genomic RNAs of diverse mammalian viruses and, additionally, viral infection was found to be modulated by the abundance of m6A in viral RNAs. Here we show that the Arabidopsis thaliana protein atALKBH9B (At2g17970) is a demethylase that removes m6A from single-stranded RNA molecules in vitro. atALKBH9B accumulates in cytoplasmic granules, which colocalize with siRNA bodies and associate with P bodies, suggesting that atALKBH9B m6A demethylase activity could be linked to mRNA silencing and/or mRNA decay processes. Moreover, we identified the presence of m6A in the genomes of two members of the Bromoviridae family, alfalfa mosaic virus (AMV) and cucumber mosaic virus (CMV). The demethylation activity of atALKBH9B affected the infectivity of AMV but not of CMV, correlating with the ability of atALKBH9B to interact (or not) with their coat proteins. Suppression of atALKBH9B increased the relative abundance of m6A in the AMV genome, impairing the systemic invasion of the plant, while not having any effect on CMV infection. Our findings suggest that, as recently found in animal viruses, m6A modification may represent a plant regulatory strategy to control cytoplasmic-replicating RNA viruses.

scholarly journals The 5′ Untranslated Region of Alfalfa Mosaic Virus RNA 1 Is Involved in Negative-Strand RNA Synthesis

2003 ◽  
Vol 77 (20) ◽  
pp. 11284-11289 ◽  
Author(s):  
A. Corina Vlot ◽  
John F. Bol
Keyword(s):  
Mosaic Virus ◽  
Untranslated Region ◽  
Rna Synthesis ◽  
Alfalfa Mosaic Virus ◽  
Loop Structure ◽  
Stem Loop ◽  
Genomic Rnas ◽  
Negative Strand ◽  
Stem Loop Structure ◽  
Virus Rna

ABSTRACT The three genomic RNAs of alfalfa mosaic virus each contain a unique 5′ untranslated region (5′ UTR). Replacement of the 5′ UTR of RNA 1 by that of RNA 2 or 3 yielded infectious replicons. The sequence of a putative 5′ stem-loop structure in RNA 1 was found to be required for negative-strand RNA synthesis. A similar putative 5′ stem-loop structure is present in RNA 2 but not in RNA 3.

scholarly journals Occurrence of Alfalfa mosaic virus in Soybean in Tennessee

Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1505-1505 ◽  
Author(s):  
O. L. Fajolu ◽  
R.-H. Wen ◽  
M. R. Hajimorad
Keyword(s):  
United States ◽  
Mosaic Virus ◽  
Natural Infection ◽  
Infected Plant ◽  
Alfalfa Mosaic Virus ◽  
The United States ◽  
Soybean Plant ◽  
Wide Range ◽  
Soybean Plants ◽  
Leaf Distortion

Alfalfa mosaic virus (AMV), a member of the genus Alfamovirus in the family Bromoviridae, naturally infects a wide range of plant species (1). Soybean (Glycine max (L.) Merr.) has seldom been reported as a natural host of AMV and there are limited reports of detection of AMV in field-grown soybean plants (4). However, AMV incidence in soybean fields in the midwestern United States has been on the rise in recent years, which is partly attributed to the introduction of the soybean aphid (Aphis glycines) (1,4). In June 2009, soybean plants of cv. Lee68 exhibiting moderate leaf distortion, mottling, and stunting were observed at the East Tennessee Research and Education Center. Leaf samples from 18 symptomatic plants were collected and the sap was extracted and analyzed by antigen-coated indirect ELISA (3) with polyclonal antibodies against AMV, Soybean mosaic virus (SMV), and Bean pod mottle virus (BPMV). None of the samples tested positive for BPMV, but all were found to be infected with SMV. Sap extract from 1 of 18 plants tested positive for AMV and SMV. Sap from this infected plant ground in 10 mM phosphate buffer, pH 7.0, was mechanically inoculated to Carborundum-dusted unifoliate leaves of PI96983, which contains the dominant Rsv1-locus conferring functional immunity to a majority of SMV strains (2). AMV, not SMV, was detected by ELISA in the systemically infected trifoliolate leaves that exhibited moderate mottling, mild leaf distortion, and stunting 14 days postinoculation. Sap was extracted from the infected tissues and the virus was passaged four times through PI96983 before being inoculated to Phaseolus vulgaris cv. Blue Lake. A local lesion isolate was obtained following three successive passages in this host and the isolate was propagated in soybean cv. Williams82. The biologically purified isolate was capable of infecting soybean cvs. L78-379 (Rsv1), L81-4420 (Rsv1), L29 (Rsv3), V94-5152 (Rsv4), Lee68, and Colfax upon sap inoculation. The infected plants exhibited a range of systemic symptoms including mottling, leaf distortion, necrosis, chlorosis, and moderate stunting. To characterize the virus further, total RNA was extracted from infected Williams82 leaf tissues with the RNeasy Plant Mini Kit (Qiagen, Valencia, CA). The RNA served as a template for cDNA synthesis in the presence of random primers. The resultant cDNA served as a template in a PCR assay with primers 1193 (forward) (5′-AGCTGAATTCATGAGTTCTTCACAAC-3′) and 1858 (reverse) (5′-GCTAGCGGCCGCTCAATGACGATC-3′) corresponding to nucleotides 1,193 to 1,210 and 1,858 to 1,840 of RNA3 from AMV-Kr (GenBank Accession No. AB126032), respectively. The amplified fragments were purified and directly sequenced bidirectionally using the same primers. BLAST analysis of the resultant nucleotide sequences showed 98% identity to an AMV isolate from a naturally infected soybean plant in Illinois (GenBank Accession No. HQ185569), and 97% identity to an isolate described from P. vulgaris in the United States (GenBank Accession No. AY340070.1). To our knowledge, this is the first report of natural infection of soybean by AMV in Tennessee. References: (1) J. Bol. Mol. Plant Pathol. 4:1, 2003. (2) M. R. Hajimorad and J. H. Hill. Mol. Plant-Microbe Interact. 14:587, 2001. (3) M. Malapi-Nelson et al. Plant Dis. 93:1259, 2009. (4) E. E. Mueller and C. R. Grau. Plant Dis. 91:266, 2007.

scholarly journals Brome mosaic virus defective RNAs generated during infection of barley plants

1999 ◽  
Vol 80 (9) ◽  
pp. 2511-2518 ◽  
Author(s):  
Tri Asmira Damayanti ◽  
Hideaki Nagano ◽  
Kazuyuki Mise ◽  
Iwao Furusawa ◽  
Tetsuro Okuno
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Helper Virus ◽  
Brome Mosaic Virus ◽  
Cdna Clones ◽  
Post Inoculation ◽  
Dependent Manner ◽  
Genomic Rnas ◽  
Defective Rnas

Brome mosaic virus (BMV) purified from systemically infected barley leaves 8 weeks post-inoculation (p.i.) contained defective RNAs (D-RNAs). The D-RNAs were detected in total and virion RNAs extracted from infected plants at 8 weeks p.i. or later, but not before, when barley plants had been inoculated with virions either containing or lacking D-RNA. The D-RNAs were derived from genomic RNA3 by double or mainly single deletions in the 3a protein ORF, and formed a heterogeneous population. By using in vitro transcripts of D-RNA synthesized from full-length cDNA clones, the D-RNAs were shown to replicate in a helper virus-dependent manner and to be packaged into virions in barley protoplasts. Subgenomic RNA4 was produced from the D-RNA and the coat protein was also expressed. Existence of the D-RNAs together with BMV genomic RNAs in inoculated protoplasts decreased the accumulation of 3a protein but it had no apparent effect on the accumulation of BMV genomic RNA3 or the coat protein. This is the first report of naturally occurring D-RNAs generated during prolonged infection with BMV.

scholarly journals First report of costus stripe mosaic virus infecting Tradescantia spathacea plants in Brazil

Plant Disease ◽  
2021 ◽  
Author(s):  
Gabriel Madoglio Favara ◽  
Felipe Franco de Oliverira ◽  
Camila Geovana Ferro ◽  
Heron Delgado Kraide ◽  
Eike Yudi Nishimura Carmo ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Protein Gene ◽  
Infected Plant ◽  
Nucleotide Sequences ◽  
Mild Mosaic ◽  
Rt Pcr ◽  
Chenopodium Amaranticolor ◽  
Capsid Protein Gene ◽  
Total Rna ◽  
First Report

Tradescantia spathacea (family Commelinaceae) is cultivated worldwide as an ornamental (Golczyk et al., 2013) and as medicinal plant (Tan et al., 2020). In 2019, 90 of ~180 plants of T. spathacea, grown in two beds of 4 m2 and exhibiting leaf mosaic were found in an experimental area at ESALQ/USP (Piracicaba municipality, São Paulo state, Brazil). Potyvirus-like flexuous filamentous particles were observed by transmission electron microscopy in foliar extracts of two symptomatic plants stained with 1% uranyl acetate. Total RNA was extracted using the Purelink viral RNA/DNA kit (Thermo Fisher Scientific) from leaves of two symptomatic plants and separately subjected to a reverse transcription polymerase chain reaction (RT-PCR). The potyviruses degenerate pairs of primers CIFor/CIRev (Ha et al. 2008), which amplifies a fragment corresponding to part of the cylindrical inclusion protein gene, and WCIEN/PV1 (Maciel et al. 2011), which amplifies a fragment containing part of the capsid protein gene and the 3′ untranslated region, were used. The expected amplicons (~700bp) were obtained from both total RNA extracts. Two amplicons from one sample were purified using the Wizard SV Gel and PCR Clean-Up System kit (Promega) and directly sequenced in both directions at Macrogen Inc (Seoul, South Korea). The obtained nucleotide sequences (GenBank MW430005 and MW503934) shared 95.32% and 97.79% nucleotide identity, respectively, with the corresponding sequences of the Brazilian isolate of the potyvirus costus stripe mosaic virus (CoSMV, MK286375) (Alexandre et al. 2020). Extract from an infected plant of T. spathacea was mechanically inoculated in 10 healthy plants of T. spathacea and two plants each of the following species: Capsicum annuum, Chenopodium amaranticolor, Commelina benghalensis, Datura stramonium, Gomphrena globosa, Nicandra physaloides, Nicotiana tabacum cvs. Turkish and Samsun, Solanum lycopersicum, T. palida, and T. zebrina. All T. spathacea plants exhibited mosaic and severe leaf malformation. C. benghalensis plants developed mild mosaic, whereas infected T. zebrina plants were asymptomatic. The plants of other species were not infected. RT-PCR with specific CoSMV primers CoSMVHC-F and CoSMVHC-R (Alexandre et al. 2020) confirmed the infection. Nucleotide sequences of amplicons obtained from experimentally inoculated T. spathacea and T. zebrina (MW430007 and MW430008) shared 94.56% and 94.94% identity with the corresponding sequence of a Brazilian CoSMV isolate (MK286375). None of eight virus-free plants of T. spathacea inoculated with CoSMV using Aphis craccivora exhibited symptoms, nor was CoSMV detected by RT-PCR. Lack of CoSMV transmission by A. solanella, Myzus persicae, and Uroleucon sonchi was previously reported (Alexandre et al. 2020). T. spathacea plants are commonly propagated vegetatively, and by seeds. Virus-free seeds, if available, can provide an efficient and easy way to obtain healthy plants. Only three viruses were reported in plants of the genus Tradescantia: Commelina mosaic virus, tradescantia mild mosaic virus, and a not fully characterized potyvirus (Baker and Zettler, 1988; Ciuffo et al., 2006; Kitajima 2020). CoSMV was recently reported infecting Costus spiralis and C. comosus (Alexandre et al. 2020). As far as we know, this is the first report of CoSMV infecting T. spathacea plants.

scholarly journals Cynoglossum officinale, a New Natural Host of Alfalfa mosaic virus

Plant Disease ◽  
2002 ◽  
Vol 86 (4) ◽  
pp. 444-444 ◽  
Author(s):  
M. G. Bellardi ◽  
C. Rubies-Autonell ◽  
A. Pisi
Keyword(s):  
Mosaic Virus ◽  
Protein A ◽  
Alfalfa Mosaic Virus ◽  
Botanical Garden ◽  
Natural Host ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chenopodium Amaranticolor ◽  
Serological Tests ◽  
Cynoglossum Officinale ◽  
Epidemiological Surveys

Cynoglossum officinale L. (family Boraginaceae), hound's-tongue, is a medicinal plant whose roots are used for their astringent and healing properties and for their sedative, calming, and slightly narcotic effects. This species, originating from Europe where it grows wild in mountainous fields, is cultivated only for its medicinal properties. Epidemiological surveys performed in the Emilia Romagna Region of northern Italy in the spring and autumn of 2001 revealed the presence of virus-like symptoms on C. officinale cultivated in two different locations. In the Botanical Garden of the University of Bologna, the plants showed stunting, interveinal chlorotic spots, midrib necrosis, and scarce or no seed production. In the experimental field of the Agriculture Faculty of Bologna (Imola), the plants exhibited stunting, interveinal chlorotic spots, and reduction of leaf lamina. Mechanical inoculations of sap from symptomatic leaves caused typical symptoms of Alfalfa mosaic virus (AlMV) on Chenopodium amaranticolor Coste & Reyn. (local chlorotic, necrotic lesions and systemic chlorotic vein streaking), Vigna unguicolata (L.) Walp., and Phaseolus vulgaris L. (local necrotic lesions). Using an electron microscope, examination of leaf sap obtained from infected plants stained with uranyl acetate and phosphotungstic acid did not show the presence of elongated virus particles. Serological tests, such as immunoelectron microscopy, gold-labeled decoration, and protein A sandwich indirect enzyme-linked immunosorbent assay using antiserum to AMV (PVAS 92, American Type Culture Collection, Manassas, VA, and AlMV-Vinca minor L., from the DiSTA collection, Bologna, Italy as a control), gave positive reactions, indicating that the virus in question was AlMV. To our knowledge, this is the first report of virus infection on C. officinale, a new natural host of AlMV.

scholarly journals First Report of the Natural Infection of Robinia pseudoacacia with Alfalfa mosaic virus

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 851-851 ◽  
Author(s):  
G. Delibašić ◽  
B. Tanović ◽  
J. Hrustic ◽  
I. Stanković ◽  
A. Bulajić ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Black Locust ◽  
Natural Infection ◽  
Robinia Pseudoacacia ◽  
Alfalfa Mosaic Virus ◽  
Natural Host ◽  
Post Inoculation ◽  
Rt Pcr ◽  
First Report ◽  
Negative Controls

Robinia pseudoacacia L. (family Fabaceae), commonly known as black locust, is native to the southeastern United States, but has been widely planted and naturalized in temperate regions worldwide. In Europe it is often planted alongside streets and in parks, not only because of the dense canopy and impressive flower clusters in spring, but also because it tolerates air pollution well. In June 2012, several black locust trees exhibiting yellow leaf spots accompanied by mottling and leaf deformation were observed in a park in Backa Topola, North Backa District, Serbia. Numerous aphid colonies were found colonizing symptomatic trees. Leaves collected from nine symptomatic and 10 asymptomatic trees were tested for the presence of three common aphid-transmitted viruses, Alfalfa mosaic virus (AMV), Cucumber mosaic virus, and Potato virus Y, using double-antibody sandwich (DAS)-ELISA with commercial polyclonal antibody (Bioreba AG, Reinach, Switzerland). Commercial positive and negative controls and extracts from healthy black locust leaves were included in each assay. AMV was serologically detected in all symptomatic and also in four of the asymptomatic trees, while no other tested viruses were found. Sap from affected leaves of a ELISA-positive sample (373-12) was mechanically inoculated onto five plants each of Chenopodium quinoa and Nicotiana benthamiana using 0.01 M phosphate buffer (pH 7). Symptoms including local chlorotic leaf lesions followed by mosaic on C. quinoa and a bright yellow mosaic on N. benthamiana were observed on all inoculated plants 5 and 10 days post-inoculation, respectively. The identity of the virus was confirmed using reverse transcription (RT)-PCR analysis. Total RNAs from all naturally and mechanically infected plants were isolated using RNeasy Plant Mini Kit (Qiagen, Hilden, Germany). RT-PCR was carried out using the One-Step RT-PCR Kit (Qiagen) with primer pair CP AMV1 and CP AMV2 specific to the partial CP gene and 3′-UTR of AMV RNA 3 (1). Total RNAs from Serbian AMV isolate from alfalfa (GenBank Accession No. FJ527748) and RNA extract from healthy leaves of R. pseudoacacia were used as positive and negative controls, respectively. All tested plants, as well as the positive control, yielded an amplicon of the correct predicted size (751 bp), while no amplicon was recorded in the healthy control. The amplified product of isolate 373-12 was purified with QIAquick PCR Purification Kit (Qiagen) and sequenced on ABI PRISM 3700 DNA analyzer (Macrogen, South Korea) in both directions (KC288155). Pairwise comparison of the 373-12 isolate CP sequence with those available in GenBank, conducted with MEGA5 software (4), revealed the maximum nucleotide identity of 99% (99% amino acid identity) with the soybean isolate (HQ185569) from Tennessee. AMV has a worldwide distribution and its natural host range includes over 150 plant species, including many herbaceous and several woody plants (2). To our knowledge, this is the first report of R. pseudoacacia as a natural host of AMV worldwide. This finding has potentially significant implications for the successful production of susceptible crops, considering that black locust could act as an important link in the epidemiology of AMV as it may serve as a virus reservoir (3). References: (1) M. M. Finetti-Sialer et al. J. Plant Pathol. 79:115, 1997. (2) R. Hull. Comparative Plant Virology. 2nd ed. Elsevier Academic Press, Burlington, MA, 2009. (3) E. E. Muller et al. Plant Dis. 96:506, 2012. (4) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011.

Sign in / Sign up

Export Citation Format

Share Document