Genomic comparison of plant pathogenic and nonpathogenic Serratia marcescens strains by suppressive subtractive hybridization.
Cucurbit yellow vine disease (CYVD) is caused by disease-associated Serratia marcescens strains that have phenotypes significantly different from those of nonphytopathogenic strains. To identify the genetic differences responsible for pathogenicity-related phenotypes, we used a suppressive subtractive hybridization (SSH) strategy. S. marcescens strain Z01-A, isolated from CYVD-affected zucchini, was used as the tester, whereas rice endophytic S. marcescens strain R02-A (IRBG 502) was used as the driver. SSH revealed 48 sequences, ranging from 200 to 700 bp, that were present in Z01-A but absent in R02-A. Sequence analysis showed that a large proportion of these sequences resembled genes involved in synthesis of surface structures. By construction of a fosmid library, followed by colony hybridization, selection, and DNA sequencing, a phage gene cluster and a genome island containing a fimbrial-gene cluster were identified. Arrayed dot hybridization showed that the conservation of subtracted sequences among CYVD pathogenic and nonpathogenic S. marcescens strains varied. Thirty-four sequences were present only in pathogenic strains. Primers were designed based on one Z01-A-specific sequence, A79, and used in a multiplex PCR to discriminate between S. marcescens strains causing CYVD and those from other ecological niches.
Zhang
Q
Q
Department of Entomology and Plant Pathology, 127 Noble Research Center, Oklahoma State University, Stillwater, OK 74078, USA.
Melcher
U
U
Zhou
L
L
Najar
F Z
FZ
Roe
B A
BA
Fletcher
J
J
D001483:Base Sequence; D002876:Chromosomes, Bacterial; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods; D010935:Plant Diseases / Q000382:microbiology; D010944:Plants / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping; D012706:Serratia marcescens / Q000235:genetics* / Q000472:pathogenicity
D017931:DNA Primers; D004269:DNA, Bacterial