Plasmid pSci6 from Spiroplasma citri GII-3 confers insect transmissibility to the non-transmissible strain S. citri 44

• Published in: Microbiology (Society for General Microbiology) Vol. 152; no. 9; pp. 2703 - 2716
• Main Authors: Berho, Nathalie, Duret, Sybille, Danet, Jean-Luc, Renaudin, Joel
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.09.2006; Society for General Microbiology; Microbiology Society
• Subjects: Adhesins, Bacterial - genetics; Adhesins, Bacterial - physiology; Animals; Bacteriology; Biological and medical sciences; Catharanthus roseus; Circulifer; Electroporation; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetic Markers; Genetics; Hemiptera - microbiology; Insect Vectors - microbiology; Life Sciences; Microbiology; Microbiology and Parasitology; Plasmids - genetics; Plasmids - isolation & purification; Spiroplasma; Spiroplasma citri; Spiroplasma citri - genetics; Spiroplasma citri - physiology; Transformation, Genetic; Vinca - microbiology; Spiroplasma citri; Catharanthus roseus; Genetic transfer; Apocynaceae; Mollicutes; Plasmid; Polymerase chain reaction; Mycoplasmatales; Spiroplasmataceae; Dicotyledones; Angiospermae; Bacteria; Spermatophyta; Adhesin; Southern blotting; CITRUS; BIOLOGIE MOLECULAIRE; SPIROPLASMA CITRI
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.29085-0

UMR 1090 Génomique Développement et Pouvoir Pathogène, INRA, Université de Bordeaux 2, Centre INRA de Bordeaux, 71 avenue Edouard Bourlaux, BP 81, 33883 Villenave d'Ornon Cedex, France Correspondence Joël Renaudin renaudin{at}bordeaux.inra.fr The insect-transmissible strain GII-3 of Spiroplasma citri contains plasmids pSci1–6, five of which (pSci1–5) encode adhesin-like proteins and one (pSci6) encodes protein P32, which has been associated with insect transmissibility. In contrast, S. citri strains ASP-1 and 44, which cannot be transmitted via injection into the leafhopper vector Circulifer haematoceps , lack these proteins and also do not carry plasmids pSci1–6. To further study the apparent relationship between the presence of plasmids and insect transmissibility, plasmids from S. citri GII-3 were introduced into the insect-non-transmissible S. citri strain 44 by electrotransformation using the tetM gene as the selection marker. Tetracycline-resistant transformants were shown to carry one, two or three distinct plasmids. Plasmids pSci1–6 were all detected in the transformants, pSci1 being the most frequently found, alone or together with other plasmids. Selected S. citri 44 transformants having distinct plasmid contents were submitted, separately or in combination, to experimental transmission to periwinkle ( Catharanthus roseus ) plants via injection into the leafhopper vector. The occurrence of symptomatic plants indicated that, in contrast to S. citri 44, spiroplasmal transformants were transmitted to the host plant, in which they multiplied. Spiroplasma cultures isolated from these infected plants all contained pSci6, leading to the conclusion that, under the experimental conditions used, transformation by pSci6 conferred insect transmissibility to S. citri strain 44. This is believed to be the first report of a phenotypic change associated with transformation of S. citri by natural plasmids. Abbreviations: ScARP, S. citri adhesion-related protein