Cucumber mosaic virus

The major objective of our cucumber breeding program involves breeding for CMV disease resistance to reduce losses in quality and yield. Seven half diallel cross hybrids resistant to CMV were developed at the Vegetables Breeding Dept., Hort. Res. Inst., Egypt during March, 2006. Sixteen genetically different pure inbred lines of Cucumis sativus were used to develop the hybrids obtained from different sources and selected for their CMV disease-resistance trait. The inbred lines and one commercial (Beit alpha) cultivar as a ...

A strain of Cucumber Mosaic Virus (CMV, Cucumovirus), belonging to the subgroup CMV-Ib, was characterized as the causal agent of yellow mottle diseases in Amaryllis (Hippeastrum× hybridum Leopoldii) from commercial nurseries and home gardens in the State of México. The characterization was performed by indicator host range, morphology and size of viral particle under an electron microscope and determination of

Cucumber mosaic virus (CMV) is one of the most destructive viruses in the Solanaceae family. Simple inheritance of CMV resistance in peppers has not previously been documented; all previous studies have reported that resistance to this virus is mediated by several partially dominant and recessive genes. In this study, we showed that the Capsicum annuum cultivar ‘Bukang’ contains a single dominant resistance gene against CMVKorean and CMVFNY strains. We named this resistance gene Cmr1 (Cucumber mosaic resistance 1). Analysis of the cellular localization of CMV using a CMV green fluorescent protein construct showed that in ‘Bukang,’ systemic movement of the virus from the epidermal cell layer to mesophyll cells is inhibited. Genetic mapping and FISH analysis revealed that the Cmr1 gene is located at the centromeric region of LG2, a position syntenic to the ToMV resistance locus (Tm-1) in tomatoes. Three SNP markers were developed by comparative genetic mapping: one intron-based marker using a pepper homolog of Tm-1, and two SNP markers using tomato and pepper BAC sequences mapped near Cmr1. We expect that the SNP markers developed in this study will be useful for developing CMV-resistant cultivars and for fine mapping the Cmr1 gene.

The influence of arsenic and Cucumber mosaic virus (CMV), applied separately and simultaneously on young tomato plants was studied. The plants were cultivated in containers under glasshouse conditions. Four main variants were arranged. The first one was without additional As pollution of soil, named as a control, and the other three variants, with As added at 25, 50 and 100 mg kg−1 to dry soil respectively. Half of the plants in each experimental container were inoculated with CMV and the rest uninoculated. A clear response in plant behavior under the conditions of biotic and abiotic stress was estimated. Both arsenic and virus infection had a negative effect on tomato plants by limiting the growth of their roots and above growth parts. The changes in roots were more significant than of stems. Virus infection was a stronger stress factor than arsenic applied at levels of 25 and 50 mg kg−1. The effect of each stress factor applied separately was enhanced in cases of their simultaneous application. The strongest negative effect was manifested in the infected plants, treated with excess arsenic of 100 mg kg−1. It was established that the infection, caused by CMV in tomatoes, was affected by the presence of arsenic in the soil and concentration of the latter. Doses of 25 and 50 mg kg−1 were favorable for infection development, while the dose of 100 mg kg−1 was an inhibitor.Virus infection induced stronger specific peroxidase activity (SPOA) than As treatment. The combination of both stress factors reduced the positive peroxidase response caused by virus infection. Arsenic at rate 50 and 100 mg kg−1, virus infection and the combination of both stress factors at 25 mg kg−1 reduced chlorophyll a, chlorophyll b and carotenoid content The virus infection in cases of the higher arsenic doses reduced the As effect. There was an interaction between the two effects of biotic and abiotic stress. When arsenic and virus infection were applied simultaneously, they caused modification of the effect of each stress on the plants, when applied separately.

Methods for the cryopreservation of in vitro-grown shoot tips of grapevine were recently developed  and . The present study demonstrates that grapevine virus A (GVA) can be successfully eliminated from naturally infected grapevine by cryopreservation of in vitro-grown shoot tips. The various steps taken before freezing in liquid nitrogen did not, by themselves, eliminate GVA. However, the freezing step resulted in 97% GVA elimination. The size of the shoot tips used for cryopreservation influenced their survival rate, while viral eradication was independent of their size in the range of 0.5–2.0 mm. In comparison, plant regeneration from meristems increased with size, and meristems of 0.1 mm completely failed to regenerate. Regeneration from 0.4-mm meristems reached 100%, but none of the regenerated plantlets were GVA-free. Meristems of 0.2 mm resulted in only 12% GVA-free plants. Frequency of GVA elimination was not affected by the cryopreservation procedure, be it encapsulation–dehydration or vitrification. Leaf morphology of plants regenerated from cryopreserved shoot tips was similar to that from control shoot tips. Results from the present study suggest cryopreservation of shoot tips as a simple and efficient method for eliminating GVA from infected grapevine plants.

Partial coat protein sequence analysis of Cucumber mosaic virus (CMV) isolates from Vanilla tahitensis crops in French Polynesia and V. planifolia crops on Réunion Island detected several different sequence variants of CMV isolates that were related to their geographic origin. French Polynesian isolates showed high molecular variability and clustered into two subgroup IB clades and one putative subgroup IA clade. The Réunion isolates grouped into a single subgroup IB clade. Experimental inoculation with a New Zealand isolate (NZ100) belonging to the CMV-II subgroup, demonstrated that vanilla is able to be infected by a very diverse range of CMV isolates.

Zucchini squash (Cucurbita pepo) is a systemic host for most strains of the cucumovirus Cucumber mosaic virus (CMV), although the long-distance movement of the M strain of CMV (M-CMV) is inhibited in some cultivars. However, co-infection of zucchini plants with M-CMV and the potyvirus Zucchini yellow mosaic virus strain A (ZYMV-A) allowed M-CMV to move systemically, as demon- strated by

Leaf samples of Lablab purpureus collected from two agroecological zones of Nigeria—the northern guinea savanna zone (NGSZ) and the derived savanna zone (DSZ)—were infected with viruses when serologically indexed against available antisera. Approximately 31.1 and 81.1% of the leaf samples collected from the NGSZ and DSZ, respectively, were infected. Seven viruses were found: Bean common mosaic virus (BCMV), Cowpea aphid-borne

Cereal yellow dwarf virus (CYDV) RNA has a 5′-terminal genome-linked protein (VPg). We have expressed the VPg region of the CYDV genome in bacteria and used the purified protein (bVPg) to raise an antiserum which was able to detect free VPg in extracts of CYDV-infected oat plants. A template-dependent RNA-dependent RNA polymerase (RdRp) has been produced from a CYDV membrane-bound RNA polymerase by treatment with BAL 31 nuclease. The RdRp was template specific, being able to utilize templates from CYDV plus- and minus-strand RNAs but not those of three unrelated viruses, Red clover necrotic mosaic virus , Cucumber mosaic virus , and Tobacco mosaic virus . RNA synthesis catalyzed by the RdRp required a 3′-terminal GU sequence and the presence of bVPg. Additionally, synthesis of minus-strand RNA on a plus-strand RNA template required the presence of a putative stem-loop structure near the 3′ terminus of CYDV RNA. The base-paired stem, a single-nucleotide (A) bulge in the stem, and the...

Leaf samples of Lablab purpureus collected from two agroecological zones of Nigeria—the northern guinea savanna zone (NGSZ) and the derived savanna zone (DSZ)—were infected with viruses when serologically indexed against available antisera. Approximately 31.1 and 81.1% of the leaf samples collected from the NGSZ and DSZ, respectively, were infected. Seven viruses were found: Bean common mosaic virus (BCMV), Cowpea aphid-borne mosaic virus (CABMV), Cucumber mosaic virus (CMV), Cowpea mottle virus (CPMoV), Cowpea severe mosaic virus (CPSMV), Southern bean mosaic virus (SBMV) and Tobacco mosaic virus (TMV) were detected from samples collected from NGSZ, while CMV, CPMoV, Cowpea mosaic virus (CPMV) and CPSMV were detected from samples from DSZ.

For the production of broad commercial resistance to cucumber mosaic virus (CMV) infection, tomato plants were transformed with a combination of two coat protein (CP) genes, representing both subgroups of CMV. The CP genes were cloned from the CMV-D strain and Italian CMV isolates (CMV-22 of subgroup I and CMV-PG of subgroup II) which have been shown to produce severe disease symptoms. Four plant transformation vectors were constructed: pMON18774 and pMON18775 (CMV-D CP), pMON18831 (CMV-PG CP) and pMON18833 (CMV-22 CP and CMV-PG CP). Transformed R0 plants were produced and lines were selected based on the combination of three traits: CMV CP expression at the R0 stage, resistance to CMV (subgroup I and/or II) infection in growth chamber tests in R1 expressing plants, and single transgene copy, based on R1 segregation. The results indicate that all four vector constructs generated plants with extremely high resistant to CMV infection. The single and double gene vector construct produced plants with broad resistance against strains of CMV from both subgroups I and II at high frequency. The engineered resistance is of practical value and will be applied for major Italian tomato varieties.

MxA is a key component in the interferon-induced antiviral defense in humans. After viral infections, MxA is rapidly induced and accumulates in the cytoplasm. The multiplication of many RNA viruses, including all bunyaviruses tested so far, is inhibited by MxA. These findings prompted us to express MxA in plants in an attempt to create resistance to tospoviruses. Here, we report the generation of transgenic tobacco plants that constitutively express MxA under the control of the 35 S cauliflower mosaic virus promotor. Northern and western blot analysis confirmed the expression of MxA in several transgenic plant lines. MxA expression had no obvious detrimental effects on plant growth and fertility. However, challenge experiments with tomato spotted wilt virus, tomato chlorotic spot virus, and groundnut ringspot virus revealed no increased resistance of MxA-transgenic tobacco plants to tospovirus infections. Neither was the multiplication of tobacco mosaic virus, cucumber mosaic virus ...

Antigenic sites in the cucumber mosaic virus (CMV) coat protein (CP) have been identified using a polyclonal antiserum prepared against glutaraldehyde-fixed virions. Antibodies were used to screen a random peptide library of heptamers displayed on the surface of a bacteriophage. Eight of 36 (22%) sequenced phage clones had inserts resembling a putative virion surface domain of the CMV CP. This region has the sequence LETDEL, corresponding to amino acids 194-199 in the Fny-CMV CP. The binding of phage clones to Fny-CMV antiserum was inhibited by a synthetic peptide representing this region. Six of 36 (17%) phage clones contained sequences corresponding to a C-terminal sequence in the Fny-CMV CP, which is thought to be internal in assembled virions. This sequence, EHQRIPTSGV, represents amino acids 206-215 and all but the P residue were observed in at least one clone. Four of 36 (11%) sequenced phage clones carried sequences that matched a portion of the sequence RLLLPDSV, correspondi...