title: Spiralin diversity within Iranian strains of Spiroplasma citri.
abstract: The first-cultured and most-studied spiroplasma is Spiroplasma citri, the causal agent of citrus stubborn disease, one of the three plant-pathogenic, sieve-tube-restricted, and leafhopper vector-transmitted mollicutes. In Iranian Fars province, S. citri cultures were obtained from stubborn affected citrus trees, sesame and safflower plants, and from the leafhopper vector Circulifer haematoceps. Spiralin gene sequences from different S. citri isolates were amplified by PCR, cloned, and sequenced. Phylogenetic trees based on spiralin gene sequence showed diversity and indicated the presence of three clusters among the S. citri strains. Comparison of the amino acid sequences of eleven spiralins from Iranian strains and those from the reference S. citri strain GII-3 (241 aa), Palmyre strain (242 aa), Spiroplasma kunkelii (240 aa), and Spiroplasma phoeniceum (237 aa) confirmed the conservation of general features of the protein. However, the spiralin of an S. citri isolate named Shiraz I comprised 346 amino acids and showed a large duplication of the region comprised between two short repeats previously identified in S. citri spiralins. We report in this paper the spiralin diversity in Spiroplasma strains from southern Iran and for the first time a partial internal duplication of the spiralin gene.
authors.affiliation: Plant Virology Research Centre (PVRC), College of Agriculture, Shiraz University, Shiraz, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Khanchezar
authors.forename: Laure
authors.initials: L
authors.lastname: Béven
authors.forename: Keramat
authors.initials: K
authors.lastname: Izadpanah
authors.forename: Mohammad
authors.initials: M
authors.lastname: Salehi
authors.forename: Colette
authors.initials: C
authors.lastname: Saillard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002957:Citrus / Q000382:microbiology; D004269:DNA, Bacterial; D005638:Fruit / Q000382:microbiology; D006430:Hemiptera; D007492:Iran; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D045642:Spiroplasma citri / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; C028588:spiralin