Two high-copy plasmids found in plants associated with strains of “Candidatus Phytoplasma asteris”

Complete sequences for two plasmids associated with two strains of “Candidatus Phytoplasma asteris” have been obtained. The plasmid named pPARG1 was found in Rehmannia glutinosa L. associated with phytoplasma classified in the 16Sr I-C subgroup. Plasmid pPABN1 was from phytoplasma associated with infected winter oilseed rape and classified in the 16Sr I-B subgroup. The plasmids pPARG1 (4371 nt) and pPABN1 (3529 nt) have high A + T content of about 75%, similar to that of phytoplasma genomes. Six and five open reading frames longer than 100 amino acids and organized on the same strand were recognized on pPARG1 and pPABN1, respectively. A segment about 1.6 kbp long sharing high sequence identity with the Onion yellows phytoplasma genome was found in pPABN1.

► Complete sequences for two plasmids from “C. Phytoplasma asteris” strains have been obtained. ► The plasmids pPARG1 and pPABN1 have A + T content similar to that of phytoplasma genomes. ► A 1.6 kbp segment of pPABN1 has 98% sequence identity with the Onion yellows phytoplasma genome. ► Both plasmids possesses geminivirus-like type of rep gene.