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J L Dale

Publications and source records attributed to J L Dale.

47 records · Page 3Linked to original sources
PubMed1994

Evidence for two groups of banana bunchy top virus isolates.

Banana bunchy top virus (BBTV) DNA component 1 from isolates from 10 different countries was cloned and sequenced and the sequences were aligned and compared. This analysis indicated two groups: the South Pacific group (isolates from Australia, Burundi, Egypt, Fiji, India, Tonga and Western Samoa) and the Asian group (isolates from the Philippines, Taiwan and Vietnam). The mean sequence difference within each group was 1.9 to 3.0% and between isolates from the two groups was approximately 10%, but some parts of the sequences differed more than others. However, the protein encoded by the major open reading frame, which is probably a replicase, differed by approximately 5%. The region from the beginning of the stem-loop sequence to the potential TATA box was identical in all isolates except for a two nucleotide change in the Western Samoan isolate and a single change in that of the NSW isolate. These results, together with other evidence, suggest that BBTV has spread to bananas after the initial movement of bananas from the Asian Pacific regions to Africa and the Americas.

Africa↗
PubMed1994

Papaya ringspot potyvirus: isolate variability and the origin of PRSV type P (Australia).

We have sequenced the coat protein gene of nine isolates of papaya ringspot virus (PRSV) including six Australian and three Asian isolates and compared these with four previously reported sequences of PRSV. There was up to 12% sequence variation between isolates at the nucleotide level. However, there was no significant difference between the sequences obtained from Australian isolates irrespective of whether they were PRSV type P (cucurbit or papaya infecting) or PRSV type W (cucurbit infecting) and these isolates were more closely related to one another than to any other isolate. These results imply that PRSV-P, first recorded in Australia in 1991, arose locally from PRSV-W (first recorded in Australia in 1978) rather than being introduced. Further, there was no consistent sequence difference between PRSV-P and PRSV-W isolates that would obviously account for their host range difference.

Amino Acid Sequence↗
PubMed1993

Nucleotide sequence of one component of the banana bunchy top virus genome contains a putative replicase gene.

One DNA component of the banana bunchy top virus (BBTV) genome was cloned and sequenced. This component is present as a circular, ssDNA in the virions and consists of 1111 nucleotides. It contains one large open reading frame (ORF) of 858 nucleotides in the virion sense; this ORF encodes a putative replicase based on the presence of a dNTP-binding motif (GGEGKT). Two smaller ORFs (249 and 366 nucleotides), in the complementary orientation, could not be assigned any obvious function. Neither of these ORFs had significant sequence homology with any known DNA plant virus gene or gene product. Computer analysis of this component-predicted a strong stem-loop structure in the virion sense putative untranslated region; a nonanucleotide sequence in the loop was nearly identical to the nonanucleotide invariant loop sequence of geminiviruses and coconut foliar decay virus. There is strong evidence that the genome of BBTV consists of more than one component because no ORF was found that would encode a protein the size of the BBTV coat protein. BBTV has some characteristics in common with geminiviruses but cannot be classified as one. Rather, BBTV probably belongs to an undescribed plant virus group which could also include subterranean clover stunt virus and coconut foliar decay virus.

Amino Acid Sequence↗
PubMed1992

Transient expression of the coat protein of sugarcane mosaic virus in sugarcane protoplasts and expression in Escherichia coli.

The coat protein (CP) of strain SC of sugarcane mosaic virus (SCMV-SC) was expressed transiently in sugarcane protoplasts after electroporation with one of two plasmids encoding the CP gene. The CP gene was fused with either the cauliflower mosaic virus 35S promoter or the synthetic monocotyledon promoter "Emu". The coat protein gene was also inducibly expressed in Escherichia coli when fused to the trc promoter. The protein expressed in both systems had the same electrophoretic mobility and antigenic specificity as purified SCMV-SC coat protein. Transient expression of the 35S-CP gene in protoplasts could only be demonstrated in Western blots developed with the chemiluminescence enzyme substrate luminol.

Base Sequence↗
PubMed1992

PCR amplification of a specific double-stranded RNA region of Fiji disease virus from diseased sugarcane.

A 450-bp region from one species of the segmented dsRNA genome of Fiji disease virus (FDV) was amplified from total nucleic acid extracts of diseased plants by reverse transcription with MMLV, followed by amplification with Taq DNA polymerase (RT-PCR). Other FDV-specific regions (c 150 bp and c 270 bp) were also amplified from the dsRNA template. FDV cDNA was only synthesised when the viral dsRNA template was boiled and quenched with FDV-specific or random hexamer primers. The reverse transcriptase/DNA polymerase enzyme rTth appeared to yield only the 150 bp fragment from the dsRNA template under the conditions used. The level of sensitivity of RT-PCR for purified FDV dsRNA was 100 ag, approximately 10(4)-fold more sensitive than detection with biotinylated DNA probe.

Base Sequence↗
PubMed1991

Virus-like particles associated with banana bunchy top disease contain small single-stranded DNA.

Virus-like particles were purified from banana plants with banana bunchy top disease. These particles were isometric with a diameter of 18 to 20 nm and a density of 1.28 to 1.30 g/ml in caesium sulphate. Associated with these particles were an ssDNA of about 1 kb and one major protein of Mr 20,100. DsDNA was synthesized from nucleic acid extracts from these particles and cloned. One clone, pBT338, hybridized specifically (i) with sap extracts from plants infected with banana bunchy top virus (BBTV) but not with sap extracts from healthy plants and (ii) with the small ssDNA in nucleic acid extracts from infected plants and virus-like particles. Banana bunchy top disease was transmitted from infected to healthy bananas by aphid inoculation and it was demonstrated that the small ssDNA was transmitted with the disease. It is probable that these particles represent the virions of BBTV containing small ssDNA and that the virus resembles subterranean clover stunt virus more than any other known virus.

Blotting, Southern↗
PubMed1986

Detection of Fiji disease virus in infected sugarcane by nucleic acid hybridization.

Clones of Fiji disease virus were obtained by cDNA synthesis from isolated viral genomic double-stranded RNA. Nick-translated probes made from a mixture of clones specifically detected Fiji disease virus in infected sugarcane galls, leaves and growing tips. This method for detection of Fiji disease virus is extremely sensitive, and can be used as a rapid screening procedure for the virus with very small tissue samples.

DNA↗
PubMed1984

Glycine mottle virus, a possible member of the tombusvirus group.

Glycine mottle virus ( GMeV ) was isolated from Glycine tomentella and has a restricted distribution in north Queensland. It has a very narrow experimental host range, systemically infecting several Glycine spp., but not G. max (soybean). Local infection occurred in soybean and several other legumes, but none of six species of non-legumes became infected. GMeV is extremely stable and can be purified in high concentration from G. soja . Based on the following properties it is classified as a possible new member of the tombusvirus group: isometric virions with a diameter of 30 nm (25 nm in cell section) which sediment as a single component with S20,w = 138; single, major polypeptide of molecular weight 39,000; approximately equal to 20% RNA consisting of a single component of molecular weight 1.5 X 10(6); a high concentration of virions in the cytoplasm and nuclei of infected cells, especially in cytoplasmic extrusions into the vacuole; and the presence of vesicles in peroxisomes and chloroplasts in infected cells. GMeV differs from most tombusviruses in its extremely narrow host range, and its virions showed no serological relationship to those of known members of the tombusvirus group, nor those of any other isometric virus tested.

Australia↗
PubMed1981

Protein composition of the virions of five plant rhabdoviruses.

Five plant rhabdoviruses fall into two groups based on the patterns produced by their dissociated virion proteins when separated electrophoretically. Lettuce necrotic yellows virus (LNVY) and Sonchus virus (SV) virions contained only one M protein and NS protein. Sowthistle yellow vein virus (SYVV), Sonchus yellow net virus (SYNV) and eggplant mottled dwarf virus (EMDV) virions contained two M proteins and no detectable NS protein. The M and G proteins of LNYV and SV were easily released from the nucleocapsid after incubation with 1% Nonidet P40 (NP40), whereas the G protein and only a proportion of one of the M proteins were released from the nucleocapsids of SYVV, SYNV and EMDV after incubation with 1% NP40. It was necessary to increase the NP40 concentration to 4% to release both M proteins from SYVV nucleocapsids.

Plant Viruses↗