Figure 1. Effects of hgdA, rpfG and hgdC mutations on biofilm formation and the production of extracellular polysaccharide (EPS) in X. oryzae pv.oryzicola.

(A) Increased biofilm formation was observed after mutation of rpfG, but not hgdA and hgdC deletion. Introducing the full-length rpfG gene into ΔrpfG reduced biofilm production to the wild-type level. Upper panel: The glass-bound biofilm was stained with crystal violet; Lower panel: The crystal violet in the stained biofilm on glass tubes was dissolved with 90% ethanol and detected spectrophotometrically at 590 nm. (B) EPS production was reduced when rpfG, but not hgdA and hgdC, was deleted in Xoc. The complemented strain ΔrpfG(rpfG) had a level of EPS production similar to the wild-type.