Host Of Cucumber Mosaic Virus Research Articles

Vasconcellea cauliflora – a new natural host of cucumber mosaic virus

Vasconcellea cauliflora plants exhibiting chlorotic spots, mottling and mosaic with yellowing on leaves were observed in Pune, India in October 2020. The disease incidence was 16%. The samples were screened for cucumber mosaic virus (CMV), papaya ringspot virus, tobacco mosaic virus and zucchini yellow mosaic virus using ELISA. Sap inoculation on healthy V. cauliflora plants using CMV positive DAS-ELISA samples reproduced field symptoms. The transmission upon mechanical inoculation was 100%. For further confirmation, RT-PCR was carried out using CMV coat protein gene specific primers. Amplicons of expected size (c. 650 bp) were obtained in all symptomatic and sap inoculated samples. No amplification was observed in the asymptomatic samples. BLASTn analysis revealed that the amplicon sequence shares more than 99% identity with CMV isolates and in phylogenetic analysis it clustered with CMV IB isolates. This is the first record of V. cauliflora as a natural host of CMV worldwide.

High-Throughput Sequencing Discloses the Cucumber Mosaic Virus (CMV) Diversity in Slovakia and Reveals New Hosts of CMV from the Papaveraceae Family.

Cucumber mosaic virus (CMV; Cucumovirus, Bromoviridae) is an omnipresent virus characterized by a large host range and high genetic variability. Using high-throughput sequencing, we have characterized near complete genomes of 14 Slovak CMV variants from different plant hosts. Of these, three variants originated from the Papaveraceae species (oilseed poppy, common poppy and great celandine), previously poorly described as CMV natural hosts. Based on a BLAST search and phylogenetic analysis, the Slovak CMV isolates can be divided into two genetically different Groups, Ia and II, respectively. The SL50V variant, characterized by a divergent RNA2 sequence, potentially represents a reassortant variant. In four samples (T101, SL50V, CP2, MVU2-21), the presence of satellite CMV RNA was identified along with CMV. Although mechanically transmitted to experimental cucumber plants, the role of satellite RNA in the symptomatology observed could not be established due to a complex infection of original hosts with different viruses.

Identification of natural weed hosts of Cucumber mosaic virus subgroup-I and the absence of seed transmission in weed hosts in Pakistan

ABSTRACT Every year in Pakistan the Cucumber mosaic virus (CMV) severely damages tomato crops, but little is known about the epidemiology of this disease. Tomato fields with a high incidence of CMV were tested to determine the range of potential natural alternative weed hosts of CMV. A total of 553 symptomatic leaf samples from 36 plant species representing 19 families were analysed for the presence of CMV subgroup-I and subgroup-II using triple antibody sandwich enzyme-linked immunosorbant assay (TAS-ELISA) and reverse transcription polymerase chain reaction (RT-PCR). CMV subgroup-I was detected for the first time in nine plant species: Chenopodium album, Calotropis procera, Heliotropium indicum, Cornopus didymus, Convolvulus arvensis, Melilotus indica, Galium aparine, Nicotiana plumbaginifolia and Withania somnifera. Back indexing with leaf extracts of naturally infected TAS-ELISA- and RT-PCR-positive plants of all of these weed species produced severe symptoms in tomato plants of the susceptible variety Nagina. Grow-out testing proved the absence of seed transmission of CMV subgroup-I in TAS-ELISA- and RT-PCR-positive weed species. This information is useful for reducing early CMV infection by eradicating these weed species, thereby reducing virus reservoirs and the vector aphid population. However, the TAS-ELISA and RT-PCR tests proved the absence of CMV subgroup-II in the tested samples.

Dalmatian Toadflax (Linaria dalmatica): New Host for Cucumber Mosaic Virus

To date, there have been no reports of Dalmatian toadflax serving as a host for cucumber mosaic virus (CMV). Infestations of Dalmatian toadflax may serve as a reservoir of CMV, thereby facilitating aphid transmission of CMV to both agricultural crops and native plants. The goal of this study was to determine whether Dalmatian toadflax is a host for CMV. Dalmatian toadflax seedlings were randomly assigned to two treatments (18 replicates/treatment): no inoculation (control) and inoculation with CMV (Fast New York strain). The Dalmatian toadflax seedlings were inoculated by standard mechanical methods and tested for the presence of CMV using enzyme-linked immunosorbent assay (ELISA). Ten of the 18 CMV-inoculated toadflax plants tested positive for the virus; 6 of the 18 displayed systemic mosaic chlorosis and leaf curling. All control plants tested negative. Transmission electron microscopy obtained from CMV-positive plants confirmed the presence of CMV based on physical properties. To verify CMV infestation, tobacco plants were assigned to the following treatments (six replicates/treatment): no inoculation (control), CMV-negative (control) inoculation, and a CMV-positive inoculation. Plants were inoculated by standard methods. Five of the 6 tobacco plants treated with the CMV-positive inoculum tested positive for CMV using ELISA. All control plants tested negative for the virus.

Analysis of the viability of coat-protein hybrids between Cucumber mosaic virus and Tomato aspermy virus

Coat-protein (CP) hybrids between Cucumber mosaic virus (CMV) and Tomato aspermy virus (TAV) were engineered to analyse reported CP-associated differences between these viruses. CP portions delimited by aa 1-59, 60-148 and 149-219 were exchanged in all possible combinations within TAV RNA3. The seven possible chimeras were able to replicate in tobacco protoplasts to similar levels, but only those having residues 1-59 or 60-148 from CMV were infectious to tobacco plants, a common host for CMV and TAV, and formed stable particles. When most of the movement protein (MP) of TAV was substituted for that of CMV, infectivity of CP hybrids did not vary. No hybrid was able to infect cucumber plants, a host for CMV and not for TAV. Need for MP-CP compatibility could explain these results, but shows that MP-CP compatibility conditions the use of CP chimeras to map CP-associated differences between CMV and TAV.

Capparis spinosa- a new host of Cucumber mosaic virus in Italy

In spring 2004, a survey was conducted to investigate the phytosanitary status of caper ( Capparis spinosa ) crops in Sicily, the Eolie Islands (Salina and Lipari) and Pantelleria. Two viruses have previously been isolated from caper in Salina (Campo et al ., 2000): Caper latent virus (CapLV, genus Carlaviruses , family Flexiviridae ) (Gallitelli & Di Franco, 1987) and Pittosporum vein yellowing virus (PVYV, genus Nucleorhabdovirus , family Rhabdoviridae ) (Nuzzaci et al ., 1993) . Crude sap taken from collected leaf samples was used to mechanically inoculate the experimental host species Chenopodium quinoa , C. amaranticolor , Nicotiana benthamiana and N. glutinosa . Some samples from the Eolie crops produced chlorotic local lesions on Chenopodium spp. a few days post-inoculation and severe systemic mosaic leaf malformations and shoestringing on Nicotiana spp., resembling symptoms caused by C ucumber mosaic virus (CMV, genus Cucumovirus , family Bromoviridae ). ELISA, using a CMV-specific rabbit polyclonal antiserum (ISPaVe-CMV22), detected the presence of the virus in samples from Salina and Lipari. To characterize the virus isolates, total RNA was extracted from caper leaves (Qiagen, RNeasy Plant Mini Kit) and was analysed in a one-step RT-PCR using primer sets CMV-CPI or CMVCPII (Lumia et al ., 2001), specific to I and II subgroups of CMV, respectively. An amplified product of the expected size was mostly commonly obtained when CMV-CPI primers were used (672 bp), and less frequently with CMV-CPII primers (674 bp). In a few samples both subgroups were detected. During the spring, CMV was detected in plants showing reddish mottle, vein yellowing and yellow rings or spots, and in caper plants without symptoms that showed interveinal leaf chlorosis on a few basal shoots later in summer. Plants with yellowing disorder were found to be infected with both CMV and PVYV. No CMV-infected plants were detected in Pantelleria. This is the first report of Capparis spinosa as a natural host of CMV and adds a new plant family, Capparaceae, to the already wide virus host range.

Construction of full-length cDNA clones of cucumber mosaic virus RNAs 1, 2 and 3: Generation of infectious RNA transcripts

Full-length cDNA copies of cucumber mosaic virus (CMV) RNAs 1 and 2 of the Fny strain were constructed from partial cDNA clones and were cloned downstream of bacteriophage T7 promoters. In one pair of clones, transcription proceeded from an unaltered T7 promoter such that in vitro transcripts representing RNAs 1 and 2 contained an additional 17 nucleotides at their 5' termini. In a second pair of clones, the T7 promoter/cDNA junction was altered by oligonucleotide-directed mutagenesis such that the in vitro transcripts contained only an additional G residue at their 5' ends. In addition, a full-length cDNA copy of Fny-CMV RNA 3 was constructed from two overlapping cDNA clones and was cloned downstream of an altered T7 promoter such that the resultant in vitro transcripts also contained only an additional G residue at their 5' ends. In vitro transcripts derived from all clones contained an additional C residue at their 3' ends. In vitro transcripts representing RNAs 1, 2 and 3 which contained an additional residue at each terminus were shown to be infectious together in several hosts of CMV.

Some variables affecting the use of cowpea as an assay host for cucumber mosaic virus.

A study was made of the factors affecting the production of local lesions by cucumber mosaic virus on cowpea (Vigna sinensis (L.) Endl. ex Hassk.).