Sequence analysis of two plasmids from the phytoplasma beet leafhopper-transmitted virescence agent.
The complete nucleotide sequences of the two plasmids from the phytoplasma beet leafhopper-transmitted virescence agent (BLTVA) have been determined. The larger plasmid, pBLTVA-1, was 10 785 nt in length and contained 11 putative ORFs, almost all of which were duplicated or triplicated on the plasmid due to the presence of large repeated regions. The sequence contained a series of tandem repeats, the largest of which was 338 nt long. The sequences of ORFs 4 and 11 showed homology with the replication genes of plasmids from other phytoplasmas and from geminiviruses. ORF9, the only ORF present as a single copy, showed homology with DNA primase genes from bacterial chromosomes and contained the conserved zinc finger and topoisomerase/primase domains. None of the other eight ORFs showed homology with known sequences in the GenBank database. pBLTVA-2 was 2587 nt in length, and all of its sequence was nearly identical to sequences from pBLTVA-1, most of which spanned ORFs 10 and 11, including the 338 nt tandem repeat. Analysis of 30 strains of BLTVA showed that most of the 11 putative ORFs were present, but the size of the plasmids varied in these strains.
Liefting
Lia W
LW
Department of Plant Pathology, University of California, Davis, CA 95616, USA.
Shaw
Mary E
ME
Department of Life Sciences, New Mexico Highlands University, Las Vegas, NM 87701, USA.
Kirkpatrick
Bruce C
BC
Department of Plant Pathology, University of California, Davis, CA 95616, USA.
D000818:Animals; D027461:Beta vulgaris / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D006430:Hemiptera / Q000382:microbiology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D045582:Phytoplasma / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology; D010957:Plasmids / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014675:Vegetables / Q000382:microbiology
D004269:DNA, Bacterial