Genome elements in Rhodococcus fascians D188 and PBTS Rhodococcus spp. 
R. STAMLER (1), D. Vereecke (2), I. Francis (3), J. Randall (4) (1) New Mexico State University, U.S.A.; (2) Ghent University, Belgium; (3) California State University Bakersfield, U.S.A.; (4) New Mexico State University, U.S.A.

Rhodococcus fascians is a gram-positive, pleomorphic bacterium that causes plant disease through production and modulation of plant growth regulators. The R. fascians model strain, D188, has characterized virulence genes necessary for symptomatic host colonization and hormone synthesis. Pistachio Bushy Top Syndrome (PBTS) describes a suite of symptoms affecting propagated rootstock planted in CA, AZ, and NM. Two distinct Rhodococcus spp. (PBTS 1 and PBTS 2) were isolated from diseased trees and shown to cause stunting and abnormal root and shoot development in pathogenicity assays. The 3 isolates were sequenced and assembled to the level of complete chromosomes and plasmids using the Pac Bio RS II instrument and a Hierarchical Genome Assembly Process (HGAP). In strain D188, all previously sequenced elements were identified, including the 200 KB pFiD188 linear plasmid, a 150 KB plasmid carrying cadmium resistance, and 5.1 MB chromosome. Multi-locus sequence analysis confirmed that PBTS isolate 2 is a member of the R. fascians species group, while PBTS isolate 1 is a distinct Rhodococcus species. Genome annotations identified complex secondary metabolism including novel antibiotic synthesis, heavy metal resistance, siderophore production, pilus-like assembly mechanisms, secreted proteins, transposons and other mobile elements, and prophage sequences. Growth assays, and microscopic analyses provide support for many of the predicted genomic features.

Abstract Number: P7-212
Session Type: Poster