Transcript accumulation from the rpoS gene encoding a stationary-phase sigma factor in Pseudomonas chlororaphis strain O6 is regulated by the polyphosphate kinase gene.
Polyphosphate levels are modulated by the actions of polyphosphate kinase, encoded by ppk, and exopolyphosphatase, encoded by ppx. The genes ppk and ppx are adjacent to each other in the genome of the root colonizer, Pseudomonas chlororaphis O6. A ppk-deficient mutant was more sensitive to oxidative stress than the wild-type and the ppx mutant. Transcripts from ppx increased as cultures matured from mid- to late-logarithmic and stationary phases, whereas abundance was greater for ppk in the late-logarithmic phase than in the stationary phase. Transcript accumulation from the rpoS gene, encoding the stationary-phase sigma factor RpoS, was decreased in the mid- and late-logarithmic and stationary phases in the ppk mutant. Thus, ppk regulates rpoS transcript accumulation in P. chlororaphis 06. However, mutations in either the ppk or ppx genes had no effect on induction of systemic resistance in plants colonized by P. chlororaphis O6.
Kim
H J
HJ
Agricultural Plant Stress Research Center and Environmental-Friendly Agriculture Research Center, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Korea.
Yang
K Y
KY
Cho
B H
BH
Kim
K Y
KY
Lee
M C
MC
Kim
Y H
YH
Anderson
A J
AJ
Kim
Y C
YC
D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000502:physiology; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000382:microbiology; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D017422:Sequence Analysis, DNA; D012808:Sigma Factor / Q000096:biosynthesis* / Q000235:genetics; D014026:Nicotiana / Q000382:microbiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase; D010749:Phosphoprotein Phosphatases; C080406:protein phosphatase 4