Maize Dwarf Mosaic Virus Strain Research Articles

Modified plasmodesmata inSorghum (Sorghum bicolor L Moench) leaf tissues infected by maize dwarf mosaic virus

The early acute response (EAR), a type of hypersensitive response, is defined by small chlorotic spots at the base of the youngest leaf of sorghum (Sorghum bicolor L. Moench) cultivar HOK, and usually appears within five days after inoculation with maize dwarf mosaic virus strain A (MDMV-A). These chlorotic spots become necrotic one to two days later and the leaf tissues are rapidly killed. In leaf tissues showing EAR, plasmodesmal fields contained many modified plasmodesmata of various sizes and structures within thickened cell walls. The membranous vesicles and tubules, derived from the extended terminal structures of modified plasmodesmata, were blocked by callose-like deposits in the area between the cell wall and plasmalemma. Also observed were two opposite-directed channels united via a central cavity at the middle lamella of the cell wall, one end of which was connected to the plasmalemma, but the other end sealed off to form a bulbous extension. The localized structure, an extraprotoplasmic sac containing aggregates of elongated virus-like particles associated with the modified plasmodesmata, was located between the plasmalemma and the cell wall. The sac was bound by membranes, and appeared to be sealed and completely excluded from the protoplasm. Extraprotoplasmic sacs appeared to be derived from the terminal extension of modified plasmodesmata, and these modification seem to be related to restriction of the viral spread.

Sequence Analysis of the Genomic RNA 3′‐terminal Region of a Potyvirus from Brachiaria spp. Related to Gulneagrass Mosaic Virus

AbstractThe 3'terminal region of the genomic RNA of a potyvirus isolated from Brachiaria spp. which is related to guinea grass mosaic virus (GGMV), was compared to that of members of the sugarcane mosaic subgroup of poty viruses. Reverse transcription‐polymerase chain reaction (RT‐PCR) of total nucleic acid extracted from infected B. brizantha resulted in the amplification of a DNA product of c. 0.9 kb. This product was cloned and sequenced, it has an open reading frame of 149 amino acid residues, and a 3'untranslated region (UTR) of 474 nucleotides. Optimal alignments of the 3'UTRs of the Brachiaria potyvirus and members of the sugarcane mosaic subgroup of potyviruses showed that it has nucleotide sequence similarities of c. 42. 46, 46, and 46% to maize dwarf mosaic virus strain A, sugarcane mosaic virus strains SC and MDB, and sorghum mosaic virus strain SCH, respectively. It had higher nucleotide sequence similarities of c. 88, 89, and 92% with Johnsongrass mosaic virus (JGMV) strains MDO, MDKSl and JG, respectively. Analyses of the deduced amino acid sequence of the Brachiaria potyvirus coat protein fragment revealed a 97.3% similarity to the JG strain of JGMV to which it is scrologically related. We propose that the Brachiaria potyvirus now be considered a strain of JGMV (designated JGMV‐Brac).

Characterisation of a maize-infecting potyvirus from Spain

In order to characterise and classify an unknown maize-infecting potyvirus isolated from fields in northeast Spain, the entire coat protein gene and the C-terminal twothirds of the large nuclear inclusion protein (NIb) gene were cloned and sequenced. Protein sequencing enabled the cleavage site between the two proteins to be deduced and also revealed that on storage the viral coat protein undergoes a specific degradation in which the N-terminal 39 amino acids are removed. Comparison of the nucleotide sequence of the 3′ non-coding region of the viral RNA and the predicted amino acid sequence of the coat protein with the equivalent regions of other members of the potyvirus group revealed that the Spanish virus is closely related to maize dwarf mosaic virus strain A.

Transgenic Corn Plants Expressing MDMV Strain B Coat Protein are Resistant to Mixed Infections of Maize Dwarf Mosaic Virus and Maize Chlorotic Mottle Virus

The maize dwarf mosaic virus strain B (MDMV-B) coat protein (cp) gene was cloned into a monocot expression cassette and introduced into sweet corn cell suspension cultures via particle bombardment or electroporation. Transformed cells were selected on culture media containing 300 mg/l kanamycin, and plants were regenerated. Cells from all transformed lines expressed the cp gene; and one transgenic line synthesized approximately 100-200 micrograms MDMV-cp per gram fresh weight. Plants regenerated from this line were challenged with a virus inoculum concentration adjusted to produce symptoms in nontransgenic controls at six days post inoculation. In growth chamber studies, the presence of the MDMV-cp provided resistance to inoculations with MDMV-A or MDMV-B and to mixed inoculations of MDMV and maize chlorotic mottle virus.

Effect of Nitrogen and Moisture Stress on Severity of Maize Dwarf Mosaic Virus Infection in Corn Seedlings

The impact of nitrogen and moisture stress on maize dwarf mosaic virus strain A (MDMV-A) in corn (Zea mays) was examined in greenhouse experiment. The factors were MDMV-A, moisture, and nitrogen arranged in a factorial design, with each stress either present or absent. Moisture × nitrogen interaction was significant for number of leaves, plant height, and dry weight. MDMV × moisture was significant for dry weight (.)

Maize chlorotic mottle virus in Hawaiian-grown maize: vector relations, host range and associated viruses

Studies were conducted on Kauai, Hawaii to identify potential above-ground arthropod vectors of maize chlorotic mottle virus (MCMV), to survey for plants serving as reservoirs for MCMV and also to survey for associated viruses in maize ( Zea mays) that might cause corn lethal necrosis disease. MCMV transmission studies used six arthropod species found in MCMV-infected maize fields ( Peregrinus maidis, Sardia pluto, Empoasca solana, Adoretus sinicus, Tetranychus sp. and Frankliniella williamsi). After a 1–3-day acquisition feeding period on MCMV-infected maize plants, five arthropod species gave positive test results for MCMV by enzyme-linked immunosorbent assay (ELISA), but only the thrips ( F. williamsi) were able to transmit MCMV to healthy maize plants. This is the first evidence of MCMV transmission by thrips. MCMV was found in all maize genotypes tested and was detected by infectivity tests and ELISA in all parts of the maize plant and in mature seed with 13–30% moisture. Fifteen other species of plants tested by ELISA were negative for MCMV, except for one sample of the grass, Trichachne insularis, and one sample of the dicotyledon, Melia azedarach. However, only sap from maize plant parts testing positive for MCMV by ELISA was capable of infecting healthy maize plants. All maize samples from Kauai were negative (by ELISA) for maize chlorotic dwarf virus, wheat streak mosaic virus and maize dwarf mosaic virus strain A (MDMV-A); one maize sample out of 300 tested positive for MDMV strain B. One T. insularis sample tested positive for MDMV-A.

Identification of Viruses and Mycoplasmas in Maize by Use of Light Microscopy

Maize tissues infected with maize dwarf mosaic virus (MDMV) strain A or B, maize stripe virus (MStpV), maize mosaic virus (MMV), maize rayado fino virus (MRFV), maize chlorotic dwarf virus (MCDV), maize bushy stunt mycoplasma (MBSM), or corn stunt spiroplasma (CSS) were studied by light microscopy. Intracellular inclusions in stained epidermal strips were uniquely associated with infection by MDMV-A, MDMV-B, MStpV, or MMV. For MStpV identification, paradermal sections of the leaf sheath were better sources than such sections of the leaf blade (....)

Genetics Basis of Resistance in Maize to Five Maize Dwarf Mosaic Virus Strains

Maize dwarf mosaic (MDM) is a widespread viral disease of maize (Zea mays L.) in the southern U.S. Corn Belt. An understanding of the genetics for resistance to maize dwarf mosaic virus (MDMV) will provide a rational basis for effective selection. Our objective wast o determine the genetic basis of resistance in inbred Pa405 to Strains A, B, D, E, and F of MDMV by examining the association between host symptomr esponses, and chromosomal translocation and morphologicaol r molecularm arkers. Twenty‐six translocation markers and the morphological marker yl were incorporated into inbred MI4. Linkage relationships with molecular markersw ere determinedb y restriction fragment length polymorphism (RFLP) analysis, using molecular markers UMC85, BNL6.29, UMC59a,n d UMC21T. he three approachesa ll indicated a gene or genes on either the short arm or the proximal region of the long arm( proximal to YI) of Chromosom6e i n inbred Pa405 controlling resistance to all five strains of MDMV.

Linkage between Maize Dwarf Mosaic Virus Resistance and Endosperm Color in Maize

Maize dwarf mosaic is the most widespread virus disease of maize (Zea mays L.) in the USA. The objective of this study was to determine which, if any, of eight maize inbreds with resistance to maize dwarf mosaic virus strain A (MDMV‐A) had a gene or genes for resistance linked to the endosperm color gene (Y1) on Chromosome 6. Resistant inbreds with yellow endosperm AR234, Ark342, E663, N7B, SC54, SC278, and Tx5858 were crossed onto a susceptible inbred, Mp333, which has a white endosperm Resistant inbred KyBll0 with white endosperm was crossed onto the susceptible inbred CI21 that has yellow endosperm. The F2 kernels were separated for kernel color into dark yellow, light yellow, and white kernels. Plants from the dark yellow kernels had a significantly lower proportion of diseased to healthy plants than did plants from white kernels for all F2 populations involving resistant inbreds with yellow endosperm, indicating that each of these inbreds had a gene for resistance linked to Y1. The white inbred, KyB110, also has a gene for resistance linked to Y1 because the proportion of diseased to healthy plants was lower for plants from white kernels than for plants from dark yellow kernels. Resistance to MDMV‐A for the gene(s) linked to Y1 among the resistant parents seemed to be dominant to mostly dominant except for KyBll0. The data indicated that most of the resistant lines have additional genes for resistance to MDMV that are not linked to the Yl gene. However, crossovers between the gene for resistance to MDMV and the Yl gene and/or gene penetrance could have an effect on what conclusions can be made.

Properties and in vitro Translation of Maize Dwarf Mosaic Virus RNA

SUMMARY The RNA of maize dwarf mosaic virus strain A (MDMV-A) was characterized and compared with that of strain B (MDMV-B). Glyoxal-treated MDMV-A RNA has an M r of 3·32 × 106 measured in agarose gels, compared with that of MDMV-B which is 3·41 × 106 under the same conditions. MDMV-A RNA has a Tm of 50·7 °C and a hyperchromicity of 23·3%, which are higher than those reported for MDMV-B RNA. Translation products of both RNAs in a rabbit reticulocyte cell-free system ranged from 23K to 121K. Four major polypeptide products of 57K, 91K, 100K and 117K were produced by MDMV-A RNA-directed translation, and four major products of 39K, 55K, 86K and 121K by MDMV-B RNA. Protein profiles from the two RNAs were distinct including translation products that comigrated with authentic coat protein at 37K (MDMV-A) or 39K (MDMV-B) for each strain. Anti-virion sera immunoprecipitated polypeptide products from each strain. Distinct subsets of translation products were immunoprecipitated with antisera to tobacco etch virus 49K and 54K nuclear inclusion proteins. No cell-free translation products were recognized by antisera to potato virus Y (PVY) or tobacco vein mottling virus (TVMV) helper components or antisera to the cylindrical inclusion proteins of PVY or TVMV.

Genetics of Reaction to Maize Dwarf Mosaic Virus Strain A in Several Maize Inbred Lines

(...) Resistant inbred lines B68, Oh1EP, Oh7B, and Pa405 (the B68 group) behaved homogeneously for virus reactions as lines and the F 1 of crosses with susceptible line Va50 produced only type 1 plants. In the F 2 , resistance was monogenic and completely dominant. Since no infected plants were observed in F 2 of crosses of lines within the B68 group, resistance occurred at one locus. The symbol Rmd1 is suggested for this locus. The resistant inbred lines A239, Va53, Va85, and VaOM73 (the Va53 group) produced only type 1 plants, but in the F 1 of crosses with Va50, produced some susceptible plants; however, in F 2 all segregated monogenically. In the F 2 of crosses within the Va53 group and between the Va53 and B68 groups, susceptible segregates appeared (...)

Estimates of yield loss and virus titre in sorghum hybrids infected with maize dwarf mosaic virus strain B

Sorghum genotypes having the red-leaf reaction to infection by maize dwarf mosaic virus strain B had significantly higher virus concentrations and 33–755 yield reductions. Sorghum having only the mosaic reaction to infection had low virus levels and 0–8% yield reductions.

Comparative Study of Two Maize Dwarf Mosaic Virus Strains Infecting Corn and Johnsongrass in Israel

Comparative Study of Two Maize Dwarf Mosaic Virus Strains Infecting Corn and Johnsongrass in Israel

Purification and Antiserum Preparation of Maize Dwarf Mosaic Virus

A high purity of maize dwarf mosaic virus strain B (MDMV-B) with sufficient yield was obtained by isopycnic centrifugation in cesium sulphate. The virus was infectious and nonaggregated after the purification process. Ultraviolet absorption spectrum of the purified virus showed a typical curve of nucleroprotein with a maximum at 259 and a minimum at 249 nm. The yield of purified virus was 70-80μg per g of tissue. Antiserum to MDMV-B was produced by intramuscular injection of the purified virus to a rabbit. The highest titer of the antiserum obtained 7 weeks after the first injection was 1/8 in SDS-immunodiffusion test, and 1/2048 in precipitin ring test. The completely negative reactions of MDMV-B antiserum to healthy plant extract indicated the efficiency of this method for the purification of MDMV-B. A spur was produced between antigens of an isolate of sugarcane mosaic virus (SCMV) and MDMV-B against antiserum of MDMV-B in SDS-immunodif fusion test. Using the antiserum prepared in this study, we could easily distinguish MDMV-B from strains of SCMV by either SDS-immunodiffusion test or ELISA.

Effects of Genotype and Inoculation Protocols on Resistance Evaluation of Maize to Maize Dwarf Mosaic Virus Strains

Effects of Genotype and Inoculation Protocols on Resistance Evaluation of Maize to Maize Dwarf Mosaic Virus Strains

Disease Reaction of Sorghum Hybrids to Infection by Maize Dwarf Mosaic Virus Strains A and B (1986)

Disease Reaction of Sorghum Hybrids to Infection by Maize Dwarf Mosaic Virus Strains A and B (1986)

Disease Reaction of Sorghum Hybrids to Infection by Maize Dwarf Mosaic Virus Strain A (1985)

Maize dwarf mosaic of sorghum, Sorghum bicolor (L.) Moench, is caused by maize dwarf mosaic virus (MDMV). Infection of sorghum by MDMV produces variable symptoms depending on virus strain, plant genotype, and temperature. Infection causes a yellow to dark green pattern (mosaic) and, on certain genotypes, a necrotic reaction (red-leaf) develops when the temperature drops below 21°C (69°F). Hybrids expressing the mosaic reaction when the temperature drops show less reduction in yield than plants with redleaf symptoms. Immunity to MDMV is not present in commercially available hybrid sorghums.

Serological relatedness of strains of maize dwarf mosaic and sugarcane mosaic viruses as determined by microprecipitin and enzyme‐linked immunosorbent assays

SUMMARYAntisera to maize dwarf mosaic virus strain A, B, and Kansas 1 (MDMV‐A, ‐B, ‐KS1) and sugarcane mosaic virus strains A, B, D, and H (SCMV‐A, ‐B, ‐D, ‐H) were prepared and their reactions with these and other SCMV strains (SCMV‐I, ‐J, ‐M) compared by microprecipitin tests and enzyme‐linked immunosorbent assay (ELISA). In microprecipitin tests, antibody titres in heterologous tests were unchanged or up to five two‐fold dilution steps lower than those in corresponding homologous reactions. Microprecipitin tests and ELISA distinguished the same four serogroups among the 10 viruses tested. Strains MDMV‐A and SCMV‐J comprised one serogroup; MDMV‐KS1, a second; MDMV‐B and SCMV‐A, ‐B and ‐D, a third; and SCMV‐H, ‐I and ‐M, a fourth.

Optimum Conditions for Studies of Maize Dwarf Mosaic Virus Strains A and B in Sorghum

Optimum Conditions for Studies of Maize Dwarf Mosaic Virus Strains A and B in Sorghum

Optimum Conditions for Studies of Maize Dwarf Mosaic Virus Strains A and B in Sorghum

Optimum Conditions for Studies of Maize Dwarf Mosaic Virus Strains A and B in Sorghum