Expression of extra-cellular levansucrase in Pseudomonas syringae is controlled by the in planta fitness-promoting metabolic repressor HexR.

ABSTRACT:

Background

Pseudomonas syringae pv. glycinea PG4180 causes bacterial blight on soybean plants and enters the leaf tissue through stomata or open wounds, where it encounters a sucrose-rich milieu. Sucrose is utilized by invading bacteria via the secreted enzyme, levansucrase (Lsc), liberating glucose and forming the polyfructan levan. P. syringae PG4180 possesses two functional lsc alleles transcribed at virulence-promoting low temperatures.

Results

We hypothesized that transcription of lsc is controlled by the hexose metabolism repressor, HexR, since potential HexR binding sites were identified upstream of both lsc genes. A hexR mutant of PG4180 was significantly growth-impaired when incubated with sucrose or glucose as sole carbon source, but exhibited wild type growth when

SUBMITTER: Mehmood A 

PROVIDER: S-EPMC4357207 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature