Whole genome sequence of five strains of Spiroplasma citri isolated from different host plants and its leafhopper vector

Authors: Yokomi, Raymond - Ray; RATTNER, R - Cooperative Agricultural Support Services; OSMAN, FATIMA - University Of California, Davis; MAHESHWARI, YOGITA - Foreign Agricultural Service (FAS, USDA); SELVARAJ, VIJAYANADRAJ - Foreign Agricultural Service (FAS, USDA); PAGLIACCIA, D - University Of California; Chen, Jianchi; VIDALAKIS, GEORGES - University Of California

Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2020
Publication Date: 7/2/2020
Citation: Yokomi, R.K., Rattner, R., Osman, F., Maheshwari, Y., Selvaraj, V., Pagliaccia, D., Chen, J., Vidalakis, G. 2020. Whole genome sequence of five strains of Spiroplasma citri isolated from different host plants and its leafhopper vector. BMC Research Notes. 13. Article 320. https://doi.org/10.1186/s13104-020-05160-9.
DOI: https://doi.org/10.1186/s13104-020-05160-9

Interpretive Summary: Spiroplasma citri, causal agent of citrus stubborn disease and brittle root disease of horseradish, is a bacterium with a wide host range and is transmitted by the beet leafhopper in a circulative and persistent manner. To determine the genetic diversity of S. citri, the bacterium was isolated and cultured from citrus, horseradish, and the beet leafhopper from different habitats and times in the United States. DNA from the cultures was sequenced and genome assembled for five strains of S. citri to expand the pathogen's genomic database to help improve detection assays and to gain a better understanding of the ecology, genetics, and evolution of S. citri and other spiroplasmas.

Technical Abstract: Spiroplasma citri, causal agent of citrus stubborn disease and brittle root disease of horseradish, is a bacterium with a wide host range and is transmitted by leafhoppers in a circulative and persistent manner. In the U.S., the vector of S. citri is the beet leafhopper. Five strains of S. citri were isolated and cultured from citrus, horseradish, and the beet leafhopper from different habitats and times. DNA from cultures was sequenced and genome assembled. The whole genome sequence and genomic metrics of the five strains of S. citri from these diverse sources were established. The S. citri chromosome was circularized for all five strains and ranged from 1,576,550 to 1,742,208 bp with a G+C content of 25.4-25.6%. Characterization of extrachromosomal DNAs resulted in identification of one or two plasmids, with a G+C content of 23.3 to 27.6%, from plant hosts; and eight or nine plasmids, with a G+C content of 21.65 to 29.19%, from the leafhopper. Total genome size ranged from 1,611,714 to 1,832,173 bp from plants and 1,968,976 to 2,155,613 bp from the leafhopper. These data expands the sequence database of S. citri and serves to improve understanding of the ecology, genetics, and evolution of S. citri and will assist in developing improved detection assays for this pathogen.