The phytopathogenic Burkholderia species B. glumae and
B. plantarii are the causal agents of bacterial wilt, grain rot,
and seedling blight, which threaten the rice industry globally.
Toxoflavin and tropolone are produced by these phytopathogens
and are considered the most hostile biohazards with a
broad spectrum of target organisms. However, despite their
nonspecific toxicity, the effects of toxoflavin and tropolone
on bacteria remain unknown. RNA-seq based transcriptome
analysis was employed to determine the genome-wide expression
patterns under phytotoxin treatment. Expression of 2327
and 830 genes was differentially changed by toxoflavin and
tropolone, respectively. Enriched biological pathways reflected
the down-regulation of oxidative phosphorylation and ribosome
function, beginning with the inhibition of membrane
biosynthesis and nitrogen metabolism under oxidative stress
or iron starvation. Conversely, several systems such as bacterial
chemotaxis, flagellar assembly, biofilm formation, and
sulfur/taurine transporters were highly expressed as countermeasures
against the phytotoxins. In addition, our findings
revealed that three hub genes commonly induced by both phytotoxins
function as the siderophore enterobactin, an ironchelator.
Our study provides new insights into the effects of
phytotoxins on bacteria for better understanding of the interactions
between phytopathogens and other microorganisms.
These data will also be applied as a valuable source in subsequent
applications against phytotoxins, the major virulence
factor.