Environmental stresses induce several plant pathogenic bacteria into a viable but nonculturable (VBNC) state, but the basis for VBNC is largely uncharacterized. We investigated the physiology and morphology ofthe @entity920 -induced VBNC state in the plant pathogen Ralstonia solanacearum in liquid microcosm. Supplementation of 200  M @entity3973 to the liquid microcosm completely suppressed bacterial colony formation on culture media; however, LIVE/DEAD BacLight bacterial viability staining showed that the bacterial cells maintained viability, and that the viable cells contain higher level of DNA. Based on electron microscopic observations, the bacterial cells in the VBNC state were unchanged in size, but heavily aggregated and surrounded by an unknown extracellular material. Cellular ribosome contents, however, were less, resulting in a reduction of the total RNA in VBNC cells. Proteome comparison and reverse transcription PCR analysis showed that the Dps protein production was up-regulated at the transcriptional level and that 2 catalases/peroxidases were present at lower level in VBNC cells. Cell aggregation and elevated levels of Dps protein are typical oxidative stress responses. @entity274 levels also increased in VBNC cells, which could result if catalase/peroxidase levels are reduced. Some of phenotypic changes in VBNC cells of @entity17498 could be an oxidative stress response due to @entity274 accumulation. This report is the first of the distinct phenotypic changes in cells of @entity17498 in the VBNC state.

Altered Gene Expression and Intracellular Changes of the Viable But Nonculturable State in Ralstonia solanacearum by XXXX Treatment.

@entity3973 :: ('MESH:D019327', 'Chemical') :: ['copper sulfate'] @entity920 :: ('MESH:D003300', 'Chemical') :: ['copper'] @entity274 :: ('CHEBI:16240', 'Chemical') :: ['H2O2'] @entity17498 :: ('305', 'Species') :: ['R. solanacearum']
@entity920 :: (MESH:D003300,Chemical) :: ['Copper']
